KR20180081370A - Compressor driving apparatus and chiller including the same - Google Patents

Abstract

The present invention relates to a chiller. A compressor driving apparatus according to an embodiment of the present invention includes a compressor having a compressor motor, a magnetic bearing, and a switching element, and applies a current to a bearing coil of the magnetic bearing in accordance with a switching operation, A bearing coil current detector for detecting a current applied to the bearing coil; a gap sensor for sensing a gap between the bearing coil and the bearing coil; And a control section for controlling the switching elements of the coil driving section on the basis of the gap information from the gap sensor and the current from the bearing coil current detecting section and the control section controls the switching section based on the gap information from the gap sensor or the current from the bearing coil current detecting section Is out of the reference range, it is judged as a failure, and control is performed so as to output a replacement message. Accordingly, it is possible to easily diagnose the failure of the elements inside the compressor in the magnetic floating system.

Description

[0001] The present invention relates to a compressor driving apparatus and a chiller having the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor driving apparatus and a chiller having the same, and more particularly, to a chiller capable of easily diagnosing a failure of components in a compressor in a magnetic levitation manner.

The air conditioner is a device that discharges cold air into the room to create a pleasant indoor environment. This air conditioner is installed to provide a more comfortable indoor environment to humans by adjusting the room temperature and purifying the room temperature.

Generally, the air conditioner includes an indoor unit that is configured as a heat exchanger and installed in a room, and an outdoor unit that is composed of a compressor, a heat exchanger, and the like and supplies the refrigerant to the indoor unit.

On the other hand, among the air conditioners, a chiller used in a business place or a building larger than the home generally includes a cooling tower installed on the outdoor roof and a heat exchange unit for circulating the refrigerant and exchanging heat with the cooling water sent from the cooling tower. Further, the heat exchange unit includes a compressor, a condenser, and an evaporator.

On the other hand, when chiller is driven by a compressor motor, a magnetic force is generated by flowing a current through a bearing coil to make the rotor of the compressor motor magnetic levitation, do. This method is referred to as a magnetic bearing method or a magnetic levitation method.

On the other hand, in order to drive the compressor motor in the chiller, a plurality of magnetic bearings are used, and various circuit elements are used for driving the magnetic bearings.

On the other hand, due to the characteristics of the chiller, it is necessary to promptly determine and replace the failure of the compressor.

An object of the present invention is to provide a compressor driving apparatus and a chiller having the same, which can easily perform a fault diagnosis of elements inside a compressor in a magnetic floating system.

According to an aspect of the present invention, there is provided a compressor driving apparatus including: a compressor having a compressor motor, a magnetic bearing, and a switching element, and applying a current to a bearing coil of the magnetic bearing, A coil driver for levitation or landing the rotor of the compressor motor from the magnetic bearing, a bearing coil current detector for detecting a current applied to the bearing coil, a gap between the bearing coil and the bearing coil, And a control unit for controlling the switching element of the coil driving unit based on the gap information from the gap sensor and the current from the bearing coil current detection unit, wherein the control unit controls the gap information from the gap sensor or the bearing When the current from the coil current detection unit is out of the reference range, it is determined that the current is out of order and the replacement message is output.

According to an aspect of the present invention, there is provided a chiller comprising: a compressor having a compressor motor and a magnetic bearing; and a compressor driving unit for driving the compressor, wherein the compressor driving unit includes a compressor having a compressor motor and a magnetic bearing, And a coil driver for levitation or landing the rotor of the compressor motor from the magnetic bearing by applying a current to the bearing coil of the magnetic bearing in accordance with the switching operation, A gap sensor for sensing a gap between the bearing coil and the bearing coil; gap information from the gap sensor; and based on the current from the bearing coil current detector, And a control unit for controlling the switching elements of the driving unit, wherein the control unit is configured to control the gap information from the gap sensor or the bearing coil current detection If the current from the part is out of the reference range, it is judged to be faulty and controls to output a replacement message.

A compressor driving apparatus and a chiller having the same according to an embodiment of the present invention are provided with a compressor motor having a compressor motor and a magnetic bearing and a switching element and applying a current to a bearing coil of the magnetic bearing according to a switching operation, A coil driver for levitating or landing the rotor of the compressor motor from the magnetic bearing, a bearing coil current detector for detecting the current applied to the bearing coil, and a gap between the bearing coil and the bearing coil And a control unit for controlling the switching elements of the coil driving unit based on the gap information from the gap sensor and the current from the bearing coil current detection unit, wherein the control unit controls the gap information from the gap sensor, When the current from the current detection unit is out of the reference range, It is possible to easily perform the fault diagnosis for the elements inside the compressor in the floating-type system.

Particularly, fault diagnosis for the gap sensor or the bearing coil current detector can be easily performed.

On the other hand, when the bearing coil current detection unit is in failure, the rotor of the compressor motor is controlled to land, and when the rotor of the compressor motor is landed, the current flowing through the bearing coil is stepwise lowered to realize soft landing. Accordingly, wear of the rotor and the bearing can be prevented.

On the other hand, when the flotation stabilization time is out of the third reference range when the rotor is floated, it is determined that the coil driving unit is faulty, and by outputting the coil driving unit replacement message, .

FIG. 1 is a view showing a configuration of a chiller according to an embodiment of the present invention.
Fig. 2 is a view showing the air conditioning unit of Fig. 1 in more detail.
3 is an example of an internal block diagram of the chiller of Fig.
Fig. 4 illustrates an example of an internal block diagram of the motor drive apparatus of Fig.
5 is an example of an internal circuit diagram of the motor driving apparatus of Fig.
6 is an internal block diagram of the inverter control unit of FIG.
7A is a view showing an example of the structure of the compressor of FIG.
7B is a cross-sectional view taken along line I-I 'of FIG. 7A.
Figure 7c is a side view of the compressor of Figure 7a.
Figures 8A-8C are diagrams that are referenced to illustrate the lifting and landing of the rotor in a bearing.
FIG. 9A is an example of an internal block diagram of the bearing drive unit of FIG.
FIG. 9B is an example of an internal block diagram of the bearing control unit of FIG. 9A.
10 is an example of a circuit diagram of a coil driver according to an embodiment of the present invention.
11A to 13 are views referred to in the description of the operation of the coil driver of FIG.
14 is a flowchart showing an operation method of the chiller according to the embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The suffix "module" and " part "for components used in the following description are given merely for convenience of description, and do not give special significance or role in themselves. Accordingly, the terms "module" and "part" may be used interchangeably.

FIG. 1 is a view showing a configuration of a chiller according to an embodiment of the present invention.

Referring to the drawings, a chiller 100 includes an air conditioning unit 10 in which a refrigeration cycle is formed, a cooling tower 20 for supplying cooling water to the air conditioning unit 10, And a cold water consumer 30 through which cold water to be heat-exchanged circulates. The cold water consumer 30 corresponds to a device or a space for performing air conditioning using cold water.

Between the air conditioning unit 10 and the cooling tower 20 is provided a circulation flow passage 40 through which cooling water flows so that cooling water is circulated between the air conditioning unit 10 and the cooling tower 20.

The cooling water circulating flow path 40 is provided with a cooling water intake flow path 42 for guiding the cooling water to flow into the condenser 12 and a cooling water outflow path 42 for guiding the cooling water heated in the air conditioning unit 10 to the cooling tower 20 And includes a flow path 44.

At least one of the cooling water intake flow path 42 and the cooling water outflow flow path 44 may further include a cooling water pump 46 for flowing cooling water. As an example, FIG. 2 illustrates a state in which a cooling water pump 46 is installed in the cooling water intake flow path 42.

An outflow temperature sensor 47 for sensing the temperature of the cooling water flowing into the cooling tower 20 can be installed in the cooling water outflow passage 44. The outflow temperature sensor 47 for detecting the temperature of the cooling water An intake temperature sensor 48 for measuring the temperature can be provided.

A cold water circulation passage (50) is provided between the air conditioning unit (10) and the cold water consumer (30) so that cooling water can be circulated between the two. The cold water circulation passage 50 is connected to the cold water supply passage 52 and the cold water supply unit 10 so that the cold water can circulate between the cold water consumer 30 and the air conditioning unit 10. [ 30 to guide the cold water outflow passage 54 to the outside.

A cold water pump (56) for circulating cold water is provided in at least one of the cold water inlet flow path (52) and the cold water outlet flow path (54). FIG. 2 illustrates a state in which the cold water supply passage 52 is provided with the cold water pump 56.

In the present embodiment, the cold water consumer 30 is described as a water-cooled air conditioner for exchanging air with cold water. For example, the cold water consumer 30 includes an air handling unit (AHU, Air Handling Unit) that mixes indoor air and outdoor air, then exchanges the mixed air with cold water to introduce it into the room, And a bottom pipe unit embedded in the floor of the indoor unit. FIG. 2 is a side view of the cold water consumer 30, Respectively.

The cold water consumer 30 includes a casing 61, a cold water coil 62 installed inside the casing 61 and through which cold water passes, and a cooling water pipe 62 provided on both sides of the cold water coil 62, And blowers 63 and 64 for blowing air into the room. The blower includes a first blower 63 for allowing indoor air and outdoor air to be sucked into the casing 61 and a second blower 64 for blowing out air to the outside of the casing 61 .

The casing 61 includes an indoor air suction portion 65, an indoor air discharge portion 66, an ambient air suction portion 67, and an air conditioning air discharge portion.

When the blowers 63 and 64 are driven, a part of the air introduced through the indoor air suction part 65 is discharged to the indoor air discharge part 66 and the rest is discharged to the outdoor air suction part 67 And then passes through the cold water coil 62 to perform heat exchange. Thereafter, the heat exchanged mixed air flows into the room through the air conditioning air discharge unit 68.

Fig. 2 is a view showing the air conditioning unit of Fig. 1 in more detail.

Referring to the drawings, the air conditioning unit 10 includes a compressor 11 for compressing refrigerant, a condenser 12 for introducing high-temperature and high-pressure refrigerant compressed by the compressor 11, a refrigerant condensed in the condenser 12, And an evaporator 14 for evaporating the refrigerant decompressed in the inflator 13 and a driving unit 220 for operating the compressor 11.

The air conditioning unit 10 includes a suction pipe 101 installed at the inlet side of the compressor 11 and guiding the refrigerant from the evaporator 14 to the compressor 11 and a suction pipe 101 provided at the outlet side of the compressor 11, And a discharge pipe 102 for guiding the refrigerant from the evaporator 11 to the condenser 12.

The condenser (12) and the evaporator (14) can be constituted by a shell tubular heat exchanger so as to enable heat exchange between the refrigerant and water.

The condenser 12 includes a shell 121 forming an outer shell, an inlet 122 through which the refrigerant compressed by the plurality of compressors 11a, 11b and 11c installed on one side of the shell 121 flows, a shell 121, And an outlet 123 through which the refrigerant condensed in the condenser 12 flows out.

The condenser 12 is provided with a cooling water pipe 125 for guiding the flow of the cooling water in the shell 121 and a cooling water pipe 125 installed at the end of the shell 121 to supply the cooling water supplied from the cooling tower 20 to the water- And an outlet 128 for discharging the cooling water from the condenser 12 to the cooling tower 20 through the inlet 127 and the outlet channel 44.

In the condenser 12, the cooling water flows through the cooling water pipe 125, and heat exchange is performed with the refrigerant in the shell 121 flowing into the condenser 12 through the refrigerant inlet port 122.

The evaporator 14 includes a shell 141 that forms an outer appearance, an inlet 142 that is installed on one side of the shell 141 and through which the refrigerant expanded in the inflator 13 is supplied, And an outlet 143 through which the refrigerant evaporated in the evaporator 14 flows out to the compressor 11. The outlet 143 is connected to the suction pipe 101 and the evaporated refrigerant is transferred from the evaporator 14 to the compressor 11.

Also. The evaporator 14 includes a cold water pipe 145 installed inside the shell 141 for guiding the flow of cold water, an inlet 141 installed at one side of the shell 141 for introducing cold water into the cold water pipe 145 And an outlet 148 for discharging cold water circulated in the evaporator.

The inlet channel 52 and the outlet channel 54 are connected to the inlet 141 and the outlet 148 so that the cold water can circulate between the cold water coils 62 of the consumer 30.

Meanwhile, the plurality of drivers 220a, 220b, and 220c can drive the plurality of compressors 11a, 11b, and 11c, respectively.

On the other hand, each of the plurality of drivers 220a, 220b, and 220c may include a converter, an inverter, and the like.

3 is an example of an internal block diagram of the chiller of Fig.

The chiller 100 may include an input unit 120, a communication unit 130, a memory 140, a control unit 170, and a driving unit 220.

The input unit 120 may include an operation button, a key, and the like, and may output an input signal for turning on / off the chiller 100, setting an operation, and the like.

In particular, the input unit 120 may include a plurality of switches to which an ID is assigned corresponding to the plurality of drivers 220a, 220b, and 220c, according to the embodiment of the present invention.

The plurality of switches at this time may be a hardware switch, a dip switch, and a tact switch.

For example, the plurality of switches may be first to third switches 122P1, 122P2, and 122P3 to which IDs are assigned corresponding to the plurality of drivers 220a, 220b, and 220c.

The communication unit 130 can exchange data with a peripheral device, for example, a remote control device or the mobile terminal 600 by wire or wirelessly. For example, infrared (IR) communication, RF communication, Bluetooth communication, Zigbee communication, WiFi communication, and the like can be performed.

The memory 140 of the chiller 100 may store data necessary for the operation of the chiller 100. For example, data on operation time, operation mode, and the like at the time of operation of the driving unit 220 can be stored.

In addition, the memory 140 of the chiller 100 may store management data including power consumption information of the chiller, recommended operation information, current operation information, and product management information.

In addition, the memory 140 of the chiller 100 may store diagnostic data including operation information, operation information, and error information of the chiller.

The control unit 170 can control each unit in the chiller 100. For example, the control unit 170 can control the input unit 120, the communication unit 130, the memory 140, the driving unit 220, and the like.

At this time, as shown in FIG. 2, the driving unit 220 may include a plurality of driving units 220a, 220b, and 220c.

Each of the plurality of driving units 220a, 220b and 220c includes an inverter 420, an inverter control unit 430, and an inverter control unit 430 shown in FIG. 4 for driving the plurality of compressors 11a, 11b, A motor 230 may be provided.

The controller 170 may control the plurality of drivers 220a, 220b, and 220c to selectively operate according to the magnitude of the demand load.

Specifically, the controller 170 may control the inverters 420a, 420b, and 420c in the plurality of drivers 220a, 220b, and 220c to selectively operate according to the magnitude of the demand load.

On the other hand, the control unit 170 can control the corresponding plurality of driving units to operate in accordance with the turn-on states of the plurality of switches.

In particular, the control unit 170 can control the plurality of drivers to selectively operate according to the turn-on state of the plurality of switches and the size of the demand load.

Meanwhile, the compressor motor driving unit described in the present specification can be applied to a motorless motor driven by a sensorless method in which a position sensing unit such as a hall sensor for sensing a rotor position of a motor is provided, It can be a motor drive device that can be estimated.

Meanwhile, the compressor motor driving unit 220 according to the embodiment of the present invention may also be referred to as a compressor compressor motor driving unit 220.

Fig. 4 illustrates an example of an internal block diagram of the compressor driving unit of Fig.

Referring to the drawings, the compressor 11 may include a motor 230 and a bearing coil RB.

Accordingly, the compressor driving unit 220 may include a compressor motor driving unit 220a for driving the compressor motor, and a bearing driving unit 221a for driving the bearing coil RB. Meanwhile, in this specification, the compressor driving unit 220 may be referred to as a compressor driving apparatus.

The bearing drive unit 221a controls the rotor (not shown) of the motor for driving the impeller in the compressor 11 to float or land.

To this end, the bearing drive unit 221a may include a bearing control unit 435, a coil drive unit 437, and a bearing coil RB.

The bearing control unit 435 detects gap information from a gap sensor (CB in FIG. 9A) disposed around the bearing coil and current information (hereinafter referred to as " gap information ") from the bearing coil current detection unit And outputs the switching control signal Sci for controlling the coil driver 437 based on the received gap information and the current information IB.

Then, the coil driver 437 can turn on / off the switching element based on the switching control signal Sci. A magnetic field or the like is generated or extinguished in the bearing coil RB due to the turn-on or turn-off of the switching element in the coil driving unit 437 so that the rotor (not shown) of the motor is lifted or landed .

The compressor motor driving unit 220a in the compressor driving unit 220 of FIG. 4 may include a memory 270, an inverter control unit 430, an inverter 430, and the like.

The detailed operation of the compressor motor driving unit 220a will be described in more detail with reference to Fig.

5 is an example of an internal circuit diagram of the compressor motor driving unit of Fig.

The compressor motor driving unit 220a according to the embodiment of the present invention drives the motor in a sensorless manner and may include an inverter 420 and an inverter control unit 430 have.

The compressor motor driving unit 220a according to the embodiment of the present invention may include a converter 410, a dc voltage detection unit B, a smoothing capacitor C, and an output current detection unit E. The driving unit 220 may further include an input current detection unit A, a reactor L, and the like.

The inverter control unit 430 according to the embodiment of the present invention stores the diagnostic data including the time of occurrence of the error, the operation information at the occurrence of the error, and the status information in the memory 140 or the memory 270 Can be controlled.

Meanwhile, the inverter control unit 430 periodically controls operation information and state information to be temporarily stored in the memory 140 or the memory 270, and when the error occurs, the inverter control unit 430 periodically stores operation information, , And finally store the final state information in the memory 140 or the memory 270. [

On the other hand, when an error occurs, the inverter control unit 430 controls the memory 140 or the memory 270 to store operation information at the time of occurrence of an error, and stores operation information or state information after a predetermined time from the occurrence of the error, (140) or the memory (270).

The amount of data of the last operation information and the final state information stored in the memory 140 or the memory 270 is smaller than the amount of data of the operation information at the time of error occurrence or the amount of data of the operation information or state information after a predetermined time A larger one is preferable.

The reactor L is disposed between the commercial AC power source 405, etc. and the converter 410 to perform a power factor correcting or boosting operation. The reactor L may also function to limit the harmonic current due to the fast switching of the converter 410.

The input current detection section A can detect the input current is inputted from the commercial AC power source 405. [ To this end, a current transformer (CT), a shunt resistor, or the like may be used as the input current detector A. The detected input current is may be input to the inverter control unit 430 as a discrete signal in the form of a pulse.

The converter 410 converts the commercial AC power source 405, which has passed through the reactor L, into DC power and outputs the DC power. Although the commercial AC power source 405 is shown as a single-phase AC power source in the figure, it may be a three-phase AC power source. The internal structure of the converter 410 also changes depending on the type of the commercial AC power source 405.

Meanwhile, the converter 410 may include a diode without a switching element, and may perform a rectifying operation without a separate switching operation.

For example, in the case of a single-phase AC power source, four diodes may be used in the form of a bridge, and in the case of a three-phase AC power source, six diodes may be used in the form of a bridge.

On the other hand, the converter 410 may be, for example, a half-bridge type converter in which two switching elements and four diodes are connected, and in the case of a three-phase AC power source, six switching elements and six diodes may be used .

When the converter 410 includes a switching element, the boosting operation, the power factor correction, and the DC power conversion can be performed by the switching operation of the switching element.

The smoothing capacitor C smoothes the input power supply and stores it. In the drawing, one element is exemplified by the smoothing capacitor C, but a plurality of elements are provided so that the element stability can be ensured.

For example, when a direct current power from the solar cell is supplied to the smoothing capacitor C (not shown), the direct current power is supplied to the smoothing capacitor C It may be input directly or may be DC / DC converted and input. Hereinafter, the portions illustrated in the drawings are mainly described.

On the other hand, both ends of the smoothing capacitor C are referred to as a dc stage or a dc stage because the dc power source is stored.

The dc voltage detection unit B can detect the dc voltage Vdc at both ends of the smoothing capacitor C. [ For this purpose, the dc voltage detection unit B may include a resistance element, an amplifier, and the like. The detected dc voltage source Vdc can be input to the inverter control unit 430 as a discrete signal in the form of a pulse.

The inverter 420 includes a plurality of inverter switching elements and converts the smoothed DC power supply Vdc into a three-phase AC power supply va, vb, vc having a predetermined frequency by on / off operation of the switching element, And outputs it to the synchronous motor 230.

The inverter 420 includes a pair of upper arm switching elements Sa, Sb and Sc and lower arm switching elements S'a, S'b and S'c serially connected to each other, The switching elements are connected to each other in parallel (Sa & S a, Sb & S'b, Sc & S'c). Diodes are connected in anti-parallel to each switching element Sa, S'a, Sb, S'b, Sc, S'c.

The switching elements in the inverter 420 perform ON / OFF operations of the respective switching elements based on the inverter switching control signal Sic from the inverter controller 430. [ Thus, three-phase AC power having a predetermined frequency is output to the three-phase synchronous motor 230.

The inverter control unit 430 can control the switching operation of the inverter 420 based on the sensorless method. For this, the inverter control unit 430 can receive the output current io detected by the output current detection unit E.

The inverter control unit 430 outputs the inverter switching control signal Sic to the inverter 420 to control the switching operation of the inverter 420. [ The inverter switching control signal Sic is generated and output based on the output current io detected by the output current detection section E as a switching control signal of the pulse width modulation method (PWM). Detailed operation of the output of the inverter switching control signal Sic in the inverter control unit 430 will be described later with reference to Fig.

The output current detecting section E detects the output current io flowing between the inverter 420 and the three-phase motor 230. [ That is, the current flowing in the motor 230 is detected. The output current detection unit E can detect all of the output currents ia, ib, ic of each phase or can detect the output currents of two phases using the three-phase balance.

The output current detection unit E may be located between the inverter 420 and the motor 230. For current detection, a current transformer (CT), a shunt resistor, or the like may be used.

Three shunt resistors are placed between the inverter 420 and the synchronous motor 230 or the three lower arm switching elements S'a, S'b, S'c To be connected to each other. On the other hand, it is also possible to use two shunt resistors using three phase equilibrium. On the other hand, when one shunt resistor is used, the shunt resistor may be disposed between the capacitor C and the inverter 420 described above.

The detected output current io can be applied to the inverter control unit 430 as a pulse discrete signal and the inverter switching control signal Sic is generated based on the detected output current io do. Hereinafter, the detected output current io may be described as being three-phase output currents (ia, ib, ic).

On the other hand, the three-phase motor 230 has a stator and a rotor, and each phase alternating current power of a predetermined frequency is applied to a coil of a stator of each phase (a, b, c) .

The motor 230 may be, for example, a Surface Mounted Permanent Magnet Synchronous Motor (SMPMSM), an Interior Permanent Magnet Synchronous Motor (IPMSM) A synchronous motor (Synchronous Reluctance Motor; Synrm), and the like. Among them, SMPMSM and IPMSM are permanent magnet applied Permanent Magnet Synchronous Motor (PMSM), and Synrm is characterized by having no permanent magnet.

6 is an internal block diagram of the inverter control unit of FIG.

6, the inverter control unit 430 includes an axis conversion unit 310, a speed calculation unit 320, a current command generation unit 330, a voltage command generation unit 340, an axis conversion unit 350, And a switching control signal output unit 360.

The axial conversion unit 310 receives the three-phase output currents ia, ib, ic detected by the output current detection unit E and converts the three-phase output currents ia, ib, ic into the two-phase currents iα, iβ in the stationary coordinate system.

On the other hand, the axis converting unit 310 can convert the two-phase current i ?, i? Of the still coordinate system into the two-phase current id, iq of the rotating coordinate system.

)와 연산된 속도(

)를 출력할 수 있다.Based on the two-phase current (i?, I?) Of the stationary coordinate system changed in the axis by the axis converting unit 310, the speed calculating unit 320 calculates the speed

) And the calculated speed (

Can be output.

)와 속도 지령치(ω^* _r)에 기초하여, 전류 지령치(i^* _q)를 생성한다. 예를 들어, 전류 지령 생성부(330)는, 연산 속도(

)와 속도 지령치(ω^* _r)의 차이에 기초하여, PI 제어기(335)에서 PI 제어를 수행하며, 전류 지령치(i^* _q)를 생성할 수 있다. 도면에서는, 전류 지령치로, q축 전류 지령치(i^* _q)를 예시하나, 도면과 달리, d축 전류 지령치(i^* _d)를 함께 생성하는 것도 가능하다. 한편, d축 전류 지령치(i^* _d)의 값은 0으로 설정될 수도 있다. On the other hand, the current command generation unit 330 generates the current command

(I ^* _q ) on the basis of the speed command value? ^* _R and the speed command value? ^* _R. For example, the current command generation section 330 generates the current command

The PI controller 335 performs the PI control based on the difference between the speed command value? ^* _R and the speed command value? ^* _R , and generates the current command value i ^* _q . In the figure, the q-axis current command value (i ^* _q ) is exemplified by the current command value, but it is also possible to generate the d-axis current command value (i ^* _d ) unlike the figure. On the other hand, the value of the d-axis current command value i ^* _d may be set to zero.

On the other hand, the current command generation section 330 may further include a limiter (not shown) for limiting the current command value (i ^* _q ) so that the current command value (i ^* _q ) does not exceed the allowable range.

Next, the voltage command generating unit 340 generates the voltage command generating unit 340 with the d-axis and q-axis currents (i _d , i _q ) axially transformed into the two-phase rotational coordinate system in the axial converting unit and the current command value based on ^{_{i * d, i * q)}} , and generates a d-axis, q-axis voltage command value ^{_{(v * d, v * q}} ). For example, the voltage command generation unit 340 performs PI control in the PI controller 344 based on the difference between the q-axis current (i _q ) and the q-axis current command value (i ^* _q ) It is possible to generate the axial voltage command value v ^* _q . The voltage command generation unit 340 performs PI control in the PI controller 348 based on the difference between the d-axis current i _d and the d-axis current command value i ^* _d , It is possible to generate the command value v ^* _d . The voltage command generator 340 may further include a limiter (not shown) for limiting the level of the d-axis and q-axis voltage command values v ^* _d and v ^* _q so as not to exceed the permissible range .

On the other hand, the generated d-axis and q-axis voltage command values (v ^* _d and v ^* _q ) are input to the axial conversion unit 350.

)와, d축, q축 전압 지령치(v^* _d,v^* _q)를 입력받아, 축변환을 수행한다.The axis transforming unit 350 transforms the position calculated by the velocity calculating unit 320

) And the d-axis and q-axis voltage command values (v ^* _d , v ^* _q ).

)가 사용될 수 있다.First, the axis converting unit 350 performs conversion from a two-phase rotating coordinate system to a two-phase stationary coordinate system. At this time, the position calculated by the speed calculator 320 (

) Can be used.

Then, the axial conversion unit 350 performs conversion from the two-phase stationary coordinate system to the three-phase stationary coordinate system. Through this conversion, the axial conversion unit 1050 outputs the three-phase output voltage instruction values v ^* a, v ^* b, v ^* c.

The switching control signal output section 360 generates the switching control signal Sic for inverter according to the pulse width modulation (PWM) method based on the three-phase output voltage instruction values v ^* a, v ^* b and v ^* And outputs it.

The output inverter switching control signal Sic may be converted into a gate driving signal in a gate driving unit (not shown) and input to the gate of each switching element in the inverter 420. As a result, the switching elements Sa, S'a, Sb, S'b, Sc, and S'c in the inverter 420 perform the switching operation.

7A is a view showing an example of the structure of the compressor of FIG.

Referring to the drawings, an impeller 701 and a rotor 702 may be disposed inside the compressor 11. [ The rotor 702 of the compressor motor can be connected to the impeller 701 disposed at one side of the inside of the compressor 11. [

On the other hand, the rotor 702 extends in the z-axis direction, and a T-shaped trust plate 706 can be formed near the end of the rotor 702.

A frame 704 is disposed in the case CS of the compressor 11 and a plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4 and RBC1 to RBC2 may be disposed in the frame 704. [

The plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4 and RBC1 to RBC2 may include a bobbin (not shown) and a bearing coil (not shown) wound around the bobbin.

When a current does not flow through the bearing coils of the plurality of magnetic bearings (RBa1 to RBa4, RBb1 to RBb4, RBC1 to RBC2), the surface of some of the magnetic bearings contacts the rotor 702, Magnetic levitation occurs from the surface of some of the magnetic bearings.

After the magnetic levitation, the rotor 702 of the compressor motor 230 rotates. Particularly, the rotation speed of the rotor 702 can be varied by the control of the inverter control unit 430 shown in Figs. .

The magnetic bearings RBa1 to RBa4 and RBb1 to RBb4 of the plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4 and RBC1 to RBC2 are radial magnetic bearings, The rotation can be controlled. That is, the x and y axes can be controlled.

On the other hand, the magnetic bearings RBa1 to RBa4 and RBb1 to RBb4 of the plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4 and RBC1 to RBC2 are disposed apart from the rotor 702 in the z- .

On the other hand, the magnetic bearings RBC1 to RBC2 among the plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4 and RBC1 to RBC2 are axial magnetic bearings and can control the rotation of the rotor in the axial direction have. That is, the z-axis can be controlled.

On the other hand, the magnetic bearings RBC1 to RBC2 among the plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4 and RBC1 to RBC2 may be disposed apart from a trust plate extending in the y-axis direction.

On the other hand, a plurality of gap sensors (CBa1 to CBa4, CBb1 to CBb4) for sensing the gap between the magnetic bearing and the rotor 702 are provided around the plurality of magnetic bearings (RBa1 to RBa4, RBb1 to RBb4, RBC1 to RBC2) CBb4, CBC1 to CBC2) can be arranged.

Some of the gap sensors CBC1 to CBC2 among the plurality of gap sensors CBa1 to CBa4, CBb1 to CBb4 and CBC1 to CBC2 are radial gap sensors that sense the position of the x, .

Some of the gap sensors CBC1 to CBC2 among the plurality of gap sensors CBa1 to CBa4, CBb1 to CBb4 and CBC1 to CBC2 can sense the position of the z-axis rotor as an axial gap sensor.

Meanwhile, the plurality of gap sensors CBa1 to CBa4, CBb1 to CBb4, and CBC1 to CBC2 may be implemented as hall sensors.

The bearing control unit 435 controls the plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4 and RBC1 to RBC2 based on the gap information from the plurality of gap sensors CBa1 to CBa4, CBb1 to CBb4 and CBC1 to CBC2 , In particular, the currents applied to the bearing coils of the plurality of magnetic bearings (RBa1 to RBa4, RBb1 to RBb4, RBC1 to RBC2) can be controlled.

7B is a cross-sectional view taken along line I-I 'of FIG. 7A.

Referring to FIG. 7A, RBb1 to RBb, which are radial magnetic bearings, may be disposed apart from each other according to a cross section taken along the line I-I 'in FIG. 7A.

The rotor 702 is disposed apart from the inner surface BR of the radial magnetic bearings RBb1 to RBb4. The rotor 702 of Fig. 7B shows floating.

Figure 7c is a side view of the compressor of Figure 7a.

Referring to the drawings, axial magnetic bearings RBC1 to RBC2 may be disposed on both sides of a trust plate 706 near the end of the rotor 702. [

On the other hand, a rotor 702 can be disposed at the lower end of the rust plate 706.

Figures 8A-8C are diagrams that are referenced to illustrate the lifting and landing of the rotor in a bearing.

First, FIG. 8A shows a state in which the current is not applied to the bearing coils of the plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4, RBC1 to RBC2, and the current is not applied to the inner surfaces BR of the radial magnetic bearings RBb1 to RBb4 The case where the rotor 702 is brought into contact is exemplified.

Next, FIG. 8B shows a state in which the current is applied to the bearing coils of the plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4, RBC1 to RBC2, and the current is applied from the inner surface BR of the radial magnetic bearings RBb1 to RBb4 The electrons 702 are shown floating.

On the other hand, the bearing control unit 435 can control the gap between the inner surface BR of the radial magnetic bearings RBb1 to RBb4 and the rotor 702 to be constant.

Next, FIG. 8C shows a state in which the current is not applied to the bearing coils of the plurality of magnetic bearings RBa1 to RBa4, RBb1 to RBb4, RBC1 to RBC2, and the current is not applied to the inner surfaces BR of the radial magnetic bearings RBb1 to RBb4 , And a case where the rotor 702 lands.

On the other hand, the inner surface BR of the radial magnetic bearings RBb1 to RBb4 in Figs. 8A to 8C may be the inner surface of the frame 704 in Fig. 7A.

FIG. 9A is an example of an internal block diagram of the bearing drive unit of FIG.

Referring to the drawing, the bearing driving unit 221a includes a bearing coil RB, a coil driving unit 439 for applying a current to the bearing coil RB, a bearing coil current detecting unit for detecting a current applied to the bearing coil RB, A gap sensor CB for sensing a gap between the bearing coil RB and the rotor 702, gap information Gp from the gap sensor CB, a bearing coil current detector M And a bearing control section 435 for outputting a switching control signal Sci to the coil driving section 439 based on the current IB from the control section 431. [

FIG. 9B is an example of an internal block diagram of the bearing control unit of FIG. 9A.

Referring to the drawing, the bearing control unit 435 may include a current command generation unit 910 and a duty generation unit 920.

The current command generation section 910 generates the current command value I ^* B based on the gap information Gp from the gap sensor CB and the gap command value Gp *. For example, the current command generation section 330 performs PI control in the PI controller 914 based on the difference between the gap information Gp and the gap command value Gp *, and outputs the current command value I ^* B, Lt; / RTI >

On the other hand, the current command generation section 910 may further include a limiter (not shown) for limiting the current command value I ^* B so that the current command value I ^* B does not exceed the allowable range.

The duty generating unit 920 generates the current command value I ^* B based on the current information IB from the bearing coil current detecting unit M and the current command value I ^* B. For example, the duty generator 920 performs PI control in the PI controller 924 based on the difference between the current information IB and the current command value I ^* B, and performs switching control including the duty command It is possible to generate the signal Sci.

Meanwhile, the duty generator 920 may further include a limiter (not shown) for limiting the level so that the duty command value does not exceed the permissible range.

For example, when the gap between the magnetic bearing and the rotor 702 is smaller than the gap command value Gp *, the bearing control unit 435 sets the switching control signal Sci whose duty increases to increase the gap Can be output.

At this time, the switching control signal Sci whose duty increases may mean that the switching period is increased and the duty is increased within the increased switching period.

Alternatively, the switching control signal Sci whose duty increases may mean that the duty increases within a constant switching period.

As another example, when the gap between the magnetic bearing and the rotor 702 is larger than the gap command value Gp *, the bearing control section 435 outputs the switching control signal Sci whose duty is decreased so that the gap is reduced can do.

According to the operation of the bearing control unit 435, the gap can be maintained constant when the rotor rotates.

On the other hand, the bearing control unit 435 can output a switching control signal Sci whose duty increases as the gap between the magnetic bearing and the rotor 702 increases stepwise when the rotor is floated.

On the other hand, the bearing control unit 435 can output a switching control signal Sci whose duty decreases when the rotor is landed, such that the gap between the magnetic bearing and the rotor 702 decreases stepwise.

The bearing control unit 435 controls the first mode in which the current stored in the bearing coil RB is discharged when the rotor 702 of the compressor motor 230 is loaded and the first mode in which the first capacitor Cbs is discharged, The second mode in which the current flows through the bearing coil RB can be controlled to be repeated by the power source stored in the second coil.

In particular, during the rotor landing period, the period during which the first mode is performed is preferably longer than the period during which the second mode is performed. Thereby, it is possible to control so that the current flowing through the bearing coil RB is stepwise lowered.

Accordingly, when the compressor motor is stopped in the magnetic levitation mode, the rotor of the compressor motor can be soft lanfed, and thus the rotor of the compressor motor can be prevented from being damaged. In addition, damage to the magnetic bearing, the gap sensor, and the like can be prevented. Further, stability and reliability of the compressor driving apparatus 220 and the chiller 100 having the compressor driving apparatus 220 are improved.

FIG. 10 is an example of a circuit diagram of a coil driver according to an embodiment of the present invention, and FIGS. 11A to 13 are diagrams referencing operation descriptions of the coil driver of FIG.

10, the coil driver 1200 of FIG. 10 includes a first capacitor Cbs, a first capacitor Cbs, and a second capacitor Cbs, which are disposed at both ends of the dc stage (ab stage) The first switching element Sb1 is connected between both ends of the first diode element Db1 and the first capacitor Cbs and is connected between the first switching element Sb1 and the first switching element Sb1, A second diode element Db2 and a second switching element Sb2 connected in parallel to the diode element Db1.

The bearing coil RB can be connected between the first switching element Sb1 and the first diode element Db1 and between the second diode element Db2 and the second switching element Sb2 have.

That is, the DC power supply Vbs from the DC power supply unit 805 is stored in the first capacitor Cbs, and between the one end of the first capacitor Cbs and one end of the bearing coil RB, (Sb1) can be connected.

The first diode element Db1 may be connected between the other end of the first capacitor Cbs and one end of the bearing coil RB.

The second diode element Db2 may be connected between one end of the first capacitor Cbs and the other end of the bearing coil RB.

The second switching element Sb2 can be connected between the other end of the first capacitor Cbs and the other end of the bearing coil RB.

Meanwhile, the coil driver 1200 of FIG. 10 may include a second capacitor Cbk connected between the first switching device and the first diode device and storing a second DC power source.

The coil driver 1200 of FIG. 10 may include a resistance element Rbk and a third diode Dbk, which are connected between the second DC power supply Vbk and the second capacitor Cbk.

The bearing control unit 435 controls the first switching device Sb1 so that the second DC power supply Vbk is stored in the second capacitor Cbk in order to secure the driving voltage of the first switching device Sb1. And the second mode in which the second switching device Sb2 is turned on can be controlled.

The first mode is a mode in which the first switching device Sb1 and the second switching device Sb2 are driven separately and efficiently by the second DC power supply Vbk stored in the second capacitor Cbk, The driving voltage of the first switching element Sb1 can be secured.

In other words, on the basis of this bootstrap operation, it becomes possible to secure the drive voltage of the first switching device Sb1 by the second direct-current power supply Vbk stored in the second capacitor Cbk.

Meanwhile, the bearing control unit 435 can control the execution time of the first mode to be equal to or longer than the first reference time.

Since the voltage storage time in the second capacitor Cbk is determined based on the RC time constant, the first reference time can be determined based on the capacitance of the second capacitor Cbk and the resistance value of the resistor element Rbk .

Accordingly, the bearing control unit 435 can control the execution time of the first mode to be variable, based on the capacitance of the second capacitor Cbk and the resistance value of the resistor Rbk. Thereby, a sufficient first mode execution time is secured, and the driving voltage of the first switching device Sb1 can be secured.

On the other hand, Fig. 11A shows an operation according to the second mode.

11A, since the first switching device Sb1 and the second switching device Sb2 are both turned on, the first capacitor Cbs, the first switching device Sb1, the bearing coil RB, The first current path Ipath1, which flows sequentially along the element Sb2, can be illustrated. Such a second mode may be referred to as a magnetization mode. Thereby, energy can be accumulated in the bearing coil RB.

On the other hand, in order to further secure the drive voltage of the first switching device Sb1, the bearing control unit 435 controls the third mode in which both the first switching device Sb1 and the second switching device Sb2 are turned off Can be performed.

On the other hand, Fig. 11B shows the operation according to the first mode.

11B, since the first switching device Sb1 is turned off and the second switching device Sb2 is turned on, the first diode Db1, the bearing coil RB, the second switching device Sb2, A second current path Ipath2 that sequentially flows along the first current path Ipath2 may be exemplified. Such a first mode may be referred to as a freewheeling mode. Thereby, the energy stored in the bearing coil RB can be discharged.

On the other hand, the first mode is performed by the second current path Ipath2 in Fig. 11B, and the current flowing in the bearing coil RB is lowered. By the first current path Ipath1 in Fig. 11A, So that the current flowing in the bearing coil RB can rise.

The bearing control unit 435 can control the second mode in which both the first switching device Sb1 and the second switching device Sb2 are turned on to float the rotor 702 of the compressor motor have.

On the other hand, Fig. 11C shows the operation according to the third mode.

11C, the first switching device Sb1 and the second switching device Sb2 are both turned off. Therefore, the first switching device Sb1 and the second switching device Sb2 are sequentially turned off along the first diode Db1, the bearing coil RB, and the second diode Db2. The third current path Ipath3, which flows to the second current path Ipath3, can be exemplified. Such a third mode may be referred to as a discharge mode. Thereby, the energy stored in the bearing coil RB can be discharged.

On the other hand, a predetermined voltage is secured at one end of the bearing coil RB by the first mode of Fig. 11B and the third mode of Fig. 11C, and thus the first switching device Sb1 The voltage can be efficiently ensured.

11 (d) shows a control signal waveform applied to the first switching device Sb1, and FIG. 11 (b) shows a control signal waveform applied to the second switching device Sb2, 11C shows the voltage waveform Vrb applied to the bearing coil RB and Fig. 11D shows the current waveform Irb applied to the bearing coil RB,

During the Tp period, the first switching device Sb1 and the second switching device Sb2 are both turned on as shown in FIG. 11A. During the Tg period, as shown in FIG. 11B, the first switching device Sb1 is turned off, The second switching element Sb2 is turned on.

That is, the second switching element Sb2 is turned on during the Tp period, and both the first switching element Sb1 and the second switching element Sb2 are turned off during the Tr period.

Among them, bootstrapping is performed during the Tg period and the Tp period, so that the driving voltage of the first switching device Sb1 can be efficiently ensured.

On the other hand, as described above, the Tg period is preferably the first mode execution period and is equal to or longer than the first reference time.

FIG. 11E is a diagram referred to explain the duty command value generated by the duty command generator 920 of FIG. 9B.

11E shows the triangular waveform CV1 corresponding to the period T for generating the duty command value and FIGURE 11B shows the duty command value CV2 for the first switching element Sb1. 11E is a waveform showing the duty command value CV3 for the second switching element Sb2 and FIG. 11D is a waveform showing the duty ratio for the second switching element Sb2. And a command value CV3.

The larger the difference between the high level of the duty instruction value CV2 for the first switching device Sb1 and the duty level CV3 for the second switching device Sb2 is, The driving voltage can be efficiently ensured.

On the other hand, as shown in Fig. 7A, the number of the bearing coils RB is ten in the compressor 11, so ten coil drivers are used.

Accordingly, the first switching device Sb1, which is the upper arm switching element, and the second switching element Sb2, which is the lower arm switching element, in the ten coil drive sections are turned on simultaneously, . As a result, the peak current at the time of switching is reduced, and the likelihood of burnout of the circuit element is reduced.

Next, FIG. 12A illustrates the current waveform Irboy flowing in the bearing coil CB when the rotor 702 is floating, as shown in FIG. 8B.

11A and the first mode of FIG. 11B are repeatedly performed, and in particular, the second mode performing period is preferably longer than the first mode performing period for the rotor 702 floating.

On the other hand, as the rotor 702 rises, the level of the current waveform Irboy flowing in the bearing coil CB increases.

Next, Fig. 12 (b) illustrates the current waveform Irboz flowing in the bearing coil CB when the rotor 702 is stabilized after the completion of the floating.

11A and the first mode of FIG. 11B are repeatedly performed. In particular, it is preferable that the second mode execution period and the first mode execution period are substantially the same. Accordingly, the same waveform may repeatedly appear in the current waveform Irboz flowing in the bearing coil CB.

Next, FIG. 13A shows the relationship between the a-phase current waveform Irba1 flowing in the bearing coil CB, the b-phase current waveform Irbb1, the c-phase current waveform Irb2 flowing in the bearing coil CB, (Irbc1), and a d-phase current waveform Irbd1.

13A is a graph showing the relationship between the a-phase current waveform Irba1 flowing in the bearing coil CB and the b-phase current waveform (braking current waveform) flowing in the bearing coil CB when the rotor 702 rotates stably without changing the position of the rotor. Irbb1), a c-phase current waveform Irbc1, and a d-phase current waveform Irbd1.

13B shows a state in which the position of the rotor changes when the rotor 702 is rotated and the a phase current waveform Irba2 flowing in the bearing coil CB and the c phase The current waveform Irbc2 is illustrated.

It can be seen that the change in the position of the rotor occurs and the change in amplitude of the current waveform flowing through the bearing coil CB is large in order to keep the gap constant.

On the other hand, in order to stably carry out the floating of the rotor, the maintenance of the gap during the rotation of the rotor, and the landing of the rotor, it is necessary to determine whether or not the circuit elements in the compressor driving unit 220, do.

Accordingly, the present invention proposes a method for easily determining a failure of a circuit element in the compressor driving unit 220, particularly, the bearing driving unit 221a.

Particularly, according to the embodiment of the present invention, when the gap information Cp from the gap sensor CB or the current IB from the bearing coil current detection section M is out of the reference range, the bearing control section 435, It is possible to control so as to output a replacement message. Accordingly, it is possible to easily diagnose the failure of the elements inside the compressor in the magnetic floating system.

On the other hand, the failure determination method and the like will be described in more detail with reference to FIG.

14 is a flowchart showing an operation method of the chiller according to the embodiment of the present invention.

Referring to the drawing, the bearing control unit 435 senses the rotor position based on the gap information from the gap sensor CB (S1410).

Next, the bearing control section 435 controls the lifting up of the rotor (S1415).

For example, the bearing control unit 435 can control the second mode of FIG. 11A and the first mode of FIG. 11B to be repeatedly performed.

11A, the bearing control unit 435 controls both the first switching device S1 and the second switching device S2 to be turned on. Thereafter, as shown in FIG. 11B, the first switching device S1 S1) and the second switching element S2 are turned on.

At this time, as shown in FIG. 11A, the bearing control unit 435 can control the period in which the second mode is performed to be longer than the period in which the first mode is performed, as shown in FIG. 11B.

At this time, the bearing control unit 435 can receive the gap information from the gap sensor CB in real time, and accordingly, determine which bearing coil among the plurality of bearing coils is more likely to apply current. For example, the smaller the gap information size, the more current may be applied to the bearing coil.

Meanwhile, the bearing control unit 435 can determine whether the output of the gap sensor during the rotor lifting is normal (S1420).

For example, when the gap information from the gap sensor CB is out of the first reference range, the bearing control unit 435 determines that the gap sensor CB is faulty (S14112) and outputs a gap sensor replacement message Can be controlled.

The gap sensor replacement message may be displayed, output as a sound, or transmitted through the communication unit 130 to the mobile terminal 600 or the like.

Next, when the gap information from the gap sensor CB does not deviate from the first reference range, the bearing control unit 435 determines that the gap information is normal and controls the next step to be performed.

Next, the bearing control unit 435 can determine whether the rotor flotation stabilization time is normal after completion of rotor flotation (S1425).

The bearing control unit 435 determines that the coil driving unit 435 is faulty if the floating stabilization time is out of the third reference range when the rotor 702 is lifted up (S1414), and controls to output the coil driving unit replacement message .

The coil driver replacement message may be displayed, output as a sound, or transmitted via the communication unit 130 to the mobile terminal 600 or the like.

On the other hand, when the failure of the coil driver 435 is determined, the bearing control unit 435 controls the first capacitor Cbs, the first switching device Sb1, the first diode Db1, The diode element Db2, and the second switching element Sb2.

On the other hand, when the failure of the coil driver 435 is determined, the bearing control unit 435 controls the first capacitor Cbs, the first switching device Sb1, the first diode Db1, It may be controlled to output a replacement message for at least one of the diode element Db2, the second switching element Sb2, and the second capacitor Cbk.

On the other hand, if the rotor flotation stabilization time is normal, the bearing control unit 435 can control the next step to be performed.

Next, the inverter control unit 430 in the compressor motor driving unit can control to rotate the rotor after completion of the rotor lifting operation (S1430).

At this time, the bearing control unit 435 can control so that the rotor maintains a constant gap so that each of Figs. 12B and 12C is performed.

On the other hand, the bearing control unit 435 determines whether the current IB from the bearing coil current detection unit M is normal (S1435), and controls the rotor so that the rotor is normally driven (S1440).

On the other hand, when the current information from the bearing coil current detection section M is out of the second reference range, the bearing control section 435 determines that the bearing coil current detection section M is faulty and outputs the bearing coil current detection section replacement message .

The bearing coil current detector replacement message may be displayed, outputted as a sound, or transmitted via the communication unit 130 to the mobile terminal 600 or the like.

The bearing control unit 435 controls the rotor 702 of the compressor motor to be landed when the bearing coil current detection unit M fails. When the rotor 702 of the compressor motor is landed, the bearing coil RB, It is possible to control the current flowing in the step-down manner.

That is, the bearing control unit 435 controls the first mode of FIG. 11B in which the current stored in the bearing coil RB is discharged when the rotor 702 of the compressor motor 230 is landed for soft landing, The second mode in Fig. 11A in which a current flows in the bearing coil RB can be controlled to be repeated by the power source stored in the capacitor Cbs.

In particular, during the rotor landing period, the period during which the first mode is performed is preferably longer than the period during which the second mode is performed. Thereby, it is possible to control so that the current flowing through the bearing coil RB is stepwise lowered.

Accordingly, the rotor of the compressor motor can be soft-laned when the compressor motor is stopped in the magnetic levitation mode due to failure of the bearing coil current detecting portion (M), so that the rotor of the compressor motor can be damaged . In addition, damage to the magnetic bearing, the gap sensor, and the like can be prevented. Further, stability and reliability of the compressor driving apparatus 220 and the chiller 100 having the compressor driving apparatus 220 are improved.

Next, the inverter control unit 430 in the compressor motor driving unit can turn off all the switching elements of the inverter 420 when the rotation of the rotor is stopped (S1445).

Thus, the bearing control unit 435 can control the first mode of 11b and the second mode of Fig. 11A to be repeated for soft landing as described above.

Accordingly, the bearing control unit 435 can seat the rotor 702 (S1450).

The compressor driving apparatus and the chiller having the compressor driving apparatus according to the embodiment of the present invention are not limited to the configuration and method of the embodiments described above but the embodiments can be applied to various implementations All or some of the examples may be selectively combined.

The compressor driving apparatus of the present invention and the operating method of the chiller having the compressor driving apparatus of the present invention can be implemented as a processor readable code on a recording medium readable by a processor provided in a compressor driving apparatus and a chiller having the same. The processor-readable recording medium includes all kinds of recording apparatuses in which data that can be read by the processor is stored.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

Claims (9)

A compressor having a compressor motor and a magnetic bearing;
A coil driver for applying a current to the bearing coil of the magnetic bearing to levitate or land the rotor of the compressor motor from the magnetic bearing in accordance with a switching operation;
A bearing coil current detector for detecting a current applied to the bearing coil;
A gap sensor for sensing a gap with the bearing coil;
And a control unit for controlling the switching element of the coil driving unit based on gap information from the gap sensor and current information from the bearing coil current detection unit,
Wherein,
Wherein when the gap information from the gap sensor or the current from the bearing coil current detection unit is out of the reference range, the control unit determines that the gap is out of order and outputs a replacement message. The method according to claim 1,
Wherein,
And to output a gap sensor replacement message when the gap information from the gap sensor is out of the first reference range,
Wherein when the current information from the bearing coil current detection unit is out of the second reference range, the control unit determines that the bearing coil current detection unit is in failure and outputs a bearing coil current detection unit replacement message. 3. The method of claim 2,
Wherein,
Wherein the controller controls the rotor of the compressor motor to be landed when the bearing coil current detector fails and controls the current flowing through the bearing coil to step down when the rotor of the compressor motor is landed. . The method of claim 3,
Wherein,
A first mode in which a current stored in the bearing coil is discharged when the rotor of the compressor motor is landed and a second mode in which a current flows in the bearing coil by a power source stored in the capacitor, Compressor drive. The method according to claim 1,
Wherein,
Wherein the control unit determines that the coil driving unit is faulty and outputs a coil driving unit replacement message when the flotation stabilization time is out of the third reference range when the rotor is floated. 6. The method of claim 5,
The coil driver may include:
A first capacitor for storing DC power;
A first switching element connected between both ends of the first capacitor, a first diode element;
A second diode element connected between both ends of the first capacitor and connected in parallel to the first switching element and the first diode element;
The bearing coil
A second switching element connected between the first switching element and the first diode element and between the second diode element and the second switching element,
Wherein,
And outputs a replacement message for at least one of the first capacitor, the first switching device, the first diode device, the second diode device, and the second switching device when the failure of the coil driver is determined Compressor drive. The method according to claim 6,
The coil driver may include:
And a second capacitor connected between the first switching element and the first diode element and storing a second DC power supply,
The control unit
Wherein when the failure of the coil driver is determined, when the failure of the coil driver is determined, the first capacitor, the first switching element, the first diode element, the second diode element, the second switching element, And outputs a replacement message for at least one of the plurality of compressors. The method according to claim 1,
Wherein,
A current command generator for outputting a current command value based on gap information sensed from the gap sensor and a gap command value;
And a duty command generator for outputting a duty command value based on the current command value and a current applied to the detected bearing coil. A chiller comprising the compressor drive device according to any one of claims 1 to 8.

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