WO2015059906A1 - Power supply control apparatus - Google Patents

Abstract

This power supply control apparatus has an input terminal, inverter unit, output terminal, input voltage detection unit, first storage unit, second storage unit, and control unit. The first storage unit is connected to the input voltage detection unit, and stores a first input voltage detected by means of the input voltage detection unit while the inverter unit is stopped. The second storage unit is connected to the input voltage detection unit, and stores a second input voltage detected by the input voltage detection unit while the inverter unit is oscillating. The control unit is connected to the first storage unit and the second storage unit, compares the first input voltage and the second input voltage with each other, and specifies a power supply as a power generator in the cases where a difference between the first input voltage and the second input voltage is larger than a predetermined voltage.

Description

Power control device

This disclosure relates to a power supply control device that receives commercial power from a commercial power source or power from an engine generator and outputs converted power. In particular, the present invention relates to a function of controlling output power when power from an engine generator is input.

Conventionally, a commercial power source that outputs commercial power (commercial AC power) or an engine generator is used as an external power source of a power supply device. In the construction industry, an engine generator that is easy to move and can secure a large capacity may be used as an external power source in order to perform new construction work such as buildings and roads, restoration work, repair work, and reinforcement work.

A conventional power supply device has a function of detecting an input voltage input from an external power supply, determining whether or not the input voltage is within a rated allowable range, and displaying an alarm if the input voltage is outside the rated allowable range. . Furthermore, the conventional power supply device also has a function of determining whether or not the input voltage is within the maximum allowable range and stopping the inverter unit if the input voltage is outside the maximum allowable range (see, for example, Patent Document 1).

Hereinafter, a conventional power supply device will be described with reference to FIG. FIG. 8 is a diagram showing a schematic configuration of a conventional power supply apparatus.

As shown in FIG. 8, the power supply device 201 includes an input terminal 202, an input side rectification unit 203, a smoothing capacitor 204, an inverter unit 205, a transformer 206, an output side rectification unit 207, an output terminal 208a, and Output terminal 208b, inverter control unit 209, power supply voltage detector 210, current detector 211, voltage comparator 212, maximum lower limit reference signal generator 213, maximum upper limit reference signal generator 214, and inverter stop A control unit 215, a voltage comparator 216, a rated lower limit reference signal generator 217, a rated upper limit reference signal generator 218, and an alarm display unit 219 are provided. Then, power is input from the external power supply 220 to the power supply device 201.

Three-phase or single-phase AC power is input from the external power source 220 to the input terminal 202 of the power supply device 201. The input side rectification unit 203 rectifies the input AC power. The smoothing capacitor 204 smoothes the DC power rectified by the input side rectifying unit 203. The inverter unit 205 receives a command from the inverter control unit 209 and converts the input DC power into high-frequency AC power. The transformer 206 transforms the high-frequency AC power generated by the inverter unit 205 on the primary side (input side) and outputs it to the secondary side (output side). The output side rectification unit 207 rectifies the high-frequency AC power transformed by the transformer 206. The DC power rectified by the output side rectification unit 207 is output to the outside as output power from the output terminal 208 a and the output terminal 208 b of the power supply device 201. In this specification, “voltage” and “current” are collectively referred to as “power”. “AC power” is a general term for “AC voltage” and “AC current”, “DC power” is a general term for “DC voltage” and “DC current”, and “input power” is “ “Input voltage” and “input current” are generic terms, and “output power” is a generic term for “output voltage” and “output current”.

The current detector 211 detects the output current output from the output terminal 208b, and outputs an output signal proportional to the output current to the inverter control unit 209.

The power supply voltage detector 210 detects an AC voltage input from the external power supply 220 to the power supply device 201 and outputs a detection signal. This detection signal is transmitted to the voltage comparator 212 and the voltage comparator 216.

In the voltage comparator 212, the voltage detected by the power supply voltage detector 210 is equal to or higher than the threshold output from the maximum lower limit reference signal generator 213 and lower than the threshold output from the maximum upper limit reference signal generator 214. If so, it is determined that it is within the maximum allowable range. In the voltage comparator 212, the voltage detected by the power supply voltage detector 210 is lower than the threshold output from the maximum lower limit reference signal generator 213 or higher than the threshold output from the maximum upper limit reference signal generator 214. In this case, it is determined that it is outside the maximum allowable range. When the voltage comparator 212 determines that the input voltage is outside the maximum allowable range, the voltage comparator 212 outputs a voltage abnormality signal to the inverter stop control unit 215 in order to protect the inverter unit 205 and the like constituting the power supply device 201. Upon receiving the voltage abnormality signal, the inverter stop control unit 215 supplies a stop command signal to the inverter control unit 209, and the inverter control unit 209 stops the inverter unit 205.

The voltage comparator 216 has a voltage detected by the power supply voltage detector 210 that is equal to or higher than the threshold output by the rated lower limit reference signal generator 217 and the threshold output by the rated upper limit reference signal generator 218. If it is less than or equal to the value, it is determined that it is within the rated tolerance. The voltage comparator 216 has a voltage detected by the power supply voltage detector 210 lower than the threshold output from the rated lower limit reference signal generator 217 or higher than the threshold output from the rated upper limit reference signal generator 218. In such a case, it is determined that it is out of the rated allowable range. At this time, the voltage comparator 216 supplies the power supply voltage fluctuation signal to the alarm display unit 219. As a result, the alarm display unit 219 turns on the red lamp and displays an alarm. The signal level of the rated lower limit reference signal is higher than the signal level of the maximum lower limit reference signal, and the signal level of the rated upper limit reference signal is lower than the signal level of the maximum upper limit reference signal.

Thus, by setting the rated allowable range within the maximum allowable range, the operator can be alerted before the inverter unit 205 of the power supply apparatus 201 stops. The conventional power supply device 201 displays an alarm if the input voltage from the external power supply 220 is outside the rated allowable range. Further, the conventional power supply device 201 protects the inverter unit 205 and the like by stopping the inverter unit 205 when the input voltage is outside the maximum range.

JP 2001-212669 A

However, the conventional power supply 201 cannot specify whether the external power source is a commercial power source or an engine generator. In addition, the output voltage of the engine generator may change abruptly. When the power supply device 201 is connected to the engine generator and the fluctuation of the input voltage to the power supply device 201 is large, the input voltage may exceed the rated allowable range and the maximum allowable range all at once. At this time, the inverter unit 205 cannot be stopped in time, and the inverter unit 205 may be damaged by a voltage outside the maximum allowable range.

This disclosure is intended to specify whether the external power supply connected to the power supply control apparatus is a commercial power supply or an engine generator. Furthermore, it aims at protecting the inverter part of a power supply control apparatus also when an external power supply is an engine generator.

In order to achieve the above object, a power supply control device of the present disclosure includes an input terminal, an inverter unit, an output terminal, an input voltage detection unit, a first storage unit, a second storage unit, and a control unit. And have. An input voltage from a power source is input to the input terminal. The inverter unit is connected to the input terminal and performs inverter control of the input voltage. The output terminal is connected to the inverter unit via a transformer and outputs an output current from the transformer. The input voltage detection unit is connected between the input terminal and the inverter unit and detects the input voltage. The first storage unit is connected to the input voltage detection unit, and stores the first input voltage detected by the input voltage detection unit while the inverter unit is stopped. The second storage unit is connected to the input voltage detection unit, and stores the second input voltage detected by the input voltage detection unit during oscillation of the inverter unit. The control unit is connected to the first storage unit and the second storage unit, compares the first input voltage with the second input voltage, and specifies whether the power source is a generator. When the difference between the first input voltage and the second input voltage is greater than a predetermined voltage, the control unit identifies the power source as a generator.

As described above, the power supply control device of the present disclosure specifies whether the external power supply is a commercial power supply or an engine generator. Furthermore, when the external power source is identified as an engine generator, the power control device of the present disclosure monitors the output current and the input voltage, and if the predetermined condition is exceeded, the input voltage of the power control device is abnormal. It is determined that And since the power supply control apparatus of this indication stops the inverter part which is oscillating based on abnormality determination, it can prevent damage to an inverter part.

FIG. 1 is a diagram illustrating a configuration of a power supply control device and an engine generator according to Embodiment 1 of the present disclosure. FIG. 2 is a diagram illustrating a relationship between the operation of the power supply control device and the output voltage of the engine generator in the first embodiment of the present disclosure. FIG. 3 is a diagram illustrating a relationship between the operation of the conventional power supply device and the output voltage of the engine generator as a comparative example of the first embodiment of the present disclosure. FIG. 4 is a diagram illustrating a configuration of the power supply control device and the engine generator according to the second embodiment of the present disclosure. FIG. 5 is a diagram illustrating a configuration of the power supply control device and the engine generator according to the third embodiment of the present disclosure. FIG. 6 is a diagram illustrating a configuration of a welding apparatus and an engine generator according to the fourth embodiment of the present disclosure. FIG. 7 is a diagram illustrating a configuration of the power supply control device and the engine generator according to the fifth embodiment of the present disclosure. FIG. 8 is a diagram illustrating a configuration of a conventional power supply device.

(Embodiment 1)
The first embodiment will be described below with reference to FIGS.

FIG. 1 is a schematic diagram in which a power supply control device 1 and an engine generator 101 that is an external power supply are connected in the present embodiment. FIG. 2 is a diagram showing the relationship between the operation of the power supply control device 1 and the output voltage of the engine generator 101 in the present embodiment. FIG. 3 is a diagram showing a relationship between the operation of the conventional power supply apparatus 201 and the output voltage of the engine generator 101 as a comparative example of the present embodiment.

As shown in FIG. 1, the power supply control device 1 includes an input terminal 2, a first rectifying unit 3, an inverter unit 4, a main transformer 5, a second rectifying unit 6, an output terminal 7a, and an output. The terminal 7b, the input voltage detection part 8, the 1st memory | storage part 9, the 2nd memory | storage part 10, the control part 11, the output current detection part 12, and the drive part 13 are provided.

As shown in FIG. 1, an engine generator 101 (generator) includes an engine 102, a generator 103, an armature winding 104, a voltage setting unit 105, an automatic voltage regulator 106, and an output terminal 107. have. In the present embodiment, AC power generated by the engine generator 101 that is a power source is input to the power source control device 1.

Next, operations of the power supply control device 1 and the engine generator 101 will be described below.

First, the operation of the power supply control device 1 will be described. Three-phase or single-phase AC power generated by the engine generator 101 is input to the input terminal 2. For example, the AC power generated by the engine generator 101 has a voltage of 200 V and a frequency of 60 Hz. In addition to the engine generator 101, the power source may be a commercial power source that outputs commercial power.

The first rectification unit 3 is connected to the input terminal 2 and rectifies AC power from the input terminal 2 into DC power.

The inverter unit 4 is connected to the first rectifying unit 3 and is constituted by a power semiconductor (not shown). The power semiconductor switching operation of the inverter unit 4 is controlled by a drive signal from the drive unit 13. The inverter unit 4 converts the DC power from the first rectification unit 3 into high-frequency AC power. Examples of the power semiconductor include an IGBT (Insulated Gate Bipolar Transistor) and a MOSFET (Metal-Oxide Semiconductor Field Effect Transistor). In addition, examples of the switching operation of the power semiconductor include PWM control (Pulse Width Modulation control). The high frequency is an oscillation frequency of 10 kHz to 50 kHz, for example.

The main transformer 5 transforms high-frequency AC power from the inverter unit 4 and outputs high-frequency AC power. The transformed high-frequency AC power has, for example, a voltage of 20 V and a frequency of 10 kHz.

The second rectification unit 6 rectifies the transformed high-frequency AC power from the main transformer 5 into DC power. The DC power from the second rectifying unit 6 is output to the outside of the power supply control device 1 from the output terminal 7a and the output terminal 7b.

The output current detection unit 12 is inserted between the second rectification unit 6 and the output terminal 7b, and detects the output current of the power supply control device 1. Further, the output current detection unit 12 is connected to the control unit 11 and outputs an output current signal proportional to the output current to the control unit 11.

The input voltage detector 8 is inserted between the input terminal 2 and the first rectifier 3 and detects the input voltage of the input AC power. If the AC power input at this time is three-phase, the voltage of all three phases or a voltage of an arbitrary phase among the three phases is detected, and if it is a single phase, a single-phase voltage is detected. The input voltage detection unit 8 is connected to the first storage unit 9 and the second storage unit 10, and the input voltage detected by the input voltage detection unit 8 is the first storage unit 9 and the second storage unit. 10 is stored.

The control unit 11 is connected to the first storage unit 9, the second storage unit 10, and the output current detection unit 12. The control unit 11 includes a voltage stored in the first storage unit 9 (first input voltage), a voltage stored in the second storage unit 10 (second input voltage), and an output current. An output current signal from the detection unit 12 is input. The control unit 11 performs an operation and specifies an external power source based on the input information and signals, generates an output command, and outputs the output command to the drive unit 13.

The drive unit 13 is connected to the control unit 11 and the inverter unit 4, and outputs a drive signal that is a signal of a power semiconductor switching operation to the inverter unit 4 based on an output command from the control unit 11. When the input voltage detection unit 8 detects all three-phase voltages, the first storage unit 9 and the second storage unit 10 can store the voltages of the three phases. As described above, the power supply control device 1 operates.

Next, the operation of the engine generator 101 will be described. The engine generator 101 uses the engine 102 as power, and rotates a rotor having a magnetic pole (not shown). Due to the rotation of the rotor, the armature winding 104 fixed around the rotor is electromagnetically induced, and an AC voltage is generated by the generator 103. The armature winding 104 has a winding inductance component (for example, 0.5 mH to 3 mH). The generated AC voltage is adjusted by the automatic voltage regulator 106 so as to be the voltage set by the voltage setting device 105. The AC voltage adjusted by the automatic voltage regulator 106 is output from the output terminal 107 to the outside of the engine generator 101.

FIG. 2 is a diagram showing the relationship between the operation of the power supply control device 1 and the output voltage of the engine generator 101 in the present embodiment.

In FIG. 2, the horizontal axis indicates time. In FIG. 2, the “operating state of the inverter unit 4” on the vertical axis indicates whether the inverter unit 4 is stopped or oscillating in a state where the power supply control device 1 is activated. In FIG. 2, the “set voltage” on the vertical axis is the output voltage of the engine generator 101 set using the voltage setter 105 of the engine generator 101. As the “set voltage”, an effective value of an AC voltage is generally used, but in this embodiment, a peak value (amplitude of the AC voltage) is described. In FIG. 2, “output voltage of the engine generator 101” on the vertical axis is an AC voltage output from the output terminal 107 of the engine generator 101. When the AC voltage output from the engine generator 101 is three-phase, three voltage waveforms that are 120 degrees out of phase are output. FIG. 2 shows an arbitrary one-phase AC voltage waveform. The “storage destination of the input voltage” on the vertical axis indicates whether the voltage detected by the input voltage detection unit 8 is stored in the first storage unit 9 or the second storage unit 10.

“The input voltage storage destination” will be described more specifically. While the inverter unit 4 is stopped, the voltage (first input voltage) detected by the input voltage detection unit 8 is stored in the first storage unit 9. On the other hand, during the oscillation of the inverter unit 4, the voltage (second input voltage) detected by the input voltage detection unit 8 is stored in the second storage unit 10. The oscillation and stop of the inverter unit 4 are performed based on a signal given from the outside of the power supply control device 1 to the control unit 11 of the power supply control device 1. Based on this signal, the control unit 11 recognizes whether the inverter unit 4 is stopped or oscillating, and outputs an output command to the drive unit 13. Further, when the inverter unit 4 is stopped, the control unit 11 instructs the first storage unit 9 to store the voltage detected by the input voltage detection unit 8. Then, the control unit 11 instructs the second storage unit 10 to store the voltage detected by the input voltage detection unit 8 when the inverter unit 4 is oscillating.

FIG. 3 is a diagram showing the relationship between the operation of the power supply device 201 and the output voltage of the engine generator 101 when the engine generator 101 is connected to the conventional power supply device 201. In FIG. 3, the horizontal axis represents time. In FIG. 3, the “operating state of the inverter unit 205” on the vertical axis indicates whether the inverter unit 205 is stopped or oscillating in a state where the power supply device 201 is activated. “Setting voltage” and “output voltage of engine generator 101” are the same as those in FIG. 3 differs from FIG. 2 in that the output voltage of the engine generator 101 is stable even when the inverter unit 205 is oscillating because the power supply device 201 has the smoothing capacitor 204. is there.

The operations of the power supply control device 1 and the engine generator 101 will be described more specifically with reference to FIGS.

In the engine generator 101, only the control unit 11 of the power supply control device 1 consumes power while the inverter unit 4 of the connected power supply control device 1 is stopped. At this time, the load of the power supply control device 1 viewed from the engine generator 101 is small, and the engine generator 101 stably outputs an AC voltage at the voltage set by the voltage setting unit 105. At this time, the power supply control device 1 stores the voltage detected by the input voltage detection unit 8 in the first storage unit 9. This state is shown at t1 in FIG. Even when the engine generator 101 is connected to the power supply device 201, stable AC power is output while the inverter unit 205 of the power supply device 201 is stopped. This state is shown at t1 in FIG.

Note that the first storage unit 9 stores the latest one of the voltages detected by the input voltage detection unit 8. In other words, the first storage unit 9 updates the voltage detected by the input voltage detection unit 8.

When the inverter unit 4 of the connected power supply control device 1 starts oscillating, the load of the power supply control device 1 viewed from the engine generator 101 increases. For this reason, the output voltage of the engine generator 101 temporarily decreases. At this time, the automatic voltage regulator 106 of the engine generator 101 detects that the output voltage has fallen below the set output set by the voltage setter 105, increases the output of the engine 102, and outputs the output of the engine generator 101. The output voltage is adjusted so that the voltage becomes the set voltage. As described above, the engine generator 101 adjusts the output of the engine 102 in accordance with the load of the connected power supply control device 1. At this time, the power supply control device 1 stores the voltage detected by the input voltage detection unit 8 in the second storage unit 10. As shown in FIG. 3, even when the engine generator 101 is connected to the power supply device 201, when the inverter unit 205 of the power supply device 201 starts oscillating, the output voltage of the engine generator 101 temporarily decreases. To do. Then, the output of the engine 102 is adjusted by the automatic voltage regulator 106, and the output voltage is adjusted to be the set voltage. Such a voltage drop due to the start of oscillation of the inverter section is shown at the beginning of t2 in FIG. 2 and at the beginning of t2 in FIG.

Next, a specific description will be given of the period after t2 in FIG. 2 and the initial period t2 in FIG.

The inverter unit 4 and the inverter unit 205 repeat energization and interruption of current at high frequency when oscillating. The influence on the engine generator 101 by the inverter unit 4 and the inverter unit 205 oscillating at a high frequency will be described.

As shown in FIG. 7, the conventional power supply device 201 includes a smoothing capacitor 204 between the input side rectification unit 203 and the inverter unit 205. When the external power source 220 is the engine generator 101, the smoothing capacitor 204 charges the DC power rectified by the input side rectifying unit 203 according to a multiple of the frequency of the input voltage from the external power source 220. Smoothing capacitor 204 discharges the charged power at a multiple or a divisor of the frequency at which inverter unit 205 operates.

Furthermore, the smoothing capacitor 204 can absorb this fluctuation when the output of the power supply apparatus 201 fluctuates instantaneously. Even when the inverter unit 205 oscillates and repeats energization and interruption of the current, the smoothing capacitor 204 can absorb the current change. Therefore, the power supply device 201 can receive a stable input voltage from the engine generator 101 regardless of the output fluctuation of the power supply device 201 or the oscillation of the inverter unit 205. Therefore, the output voltage of the engine generator 101 has a smooth waveform as indicated by t2 in FIG.

For example, if the power supply device 201 is a consumable electrode type arc welding apparatus, the output terminal 208a and the output terminal 208b are connected to the consumable electrode and the welding object, respectively. And the fluctuation | variation of an output occurs based on the short circuit and open | release which arise between a consumable electrode and a welding target object. This is an example of instantaneous output fluctuation of the power supply device 201.

On the other hand, the power supply control device 1 of the present embodiment does not have a smoothing capacitor as shown in FIG. When the external power source is the engine generator 101, the DC power rectified by the first rectification unit 3 is directly input to the inverter unit 4 at a multiple or a divisor of the frequency at which the inverter unit 4 operates. And when the output of the power supply control apparatus 1 fluctuates instantaneously, there is no smoothing capacitor that absorbs the fluctuation, so the input current of the power supply control apparatus 1 becomes unstable due to this output fluctuation. Further, even when the inverter unit 4 oscillates and the current is repeatedly turned on and off, the input current of the power supply control device 1 becomes unstable because there is no smoothing capacitor. As the input current of the power supply control device 1 becomes unstable, the output voltage of the engine generator 101 has a rough waveform as shown at t2 in FIG.

The reason why the output voltage of the engine generator 101 becomes unstable when the input current of the power supply control device 1 becomes unstable will be described. Due to the influence of the output fluctuation of the power supply control device 1, the input current from the input terminal 2 rapidly increases and then rapidly decreases. Thereby, a counter electromotive voltage is generated in the armature winding 104 due to the inductance component of the armature winding 104 mounted on the engine generator 101. Even when the inverter unit 4 oscillates and repeats energization and interruption of the current, energization and interruption of the input current from the input terminal 2 are caused and the same result is obtained.

The power generation capacity of the engine generator 101 of the present embodiment is about 1 to 10 times the rated capacity of the power supply control device 1. When the power generation capacity of the engine generator 101 is close to the rated capacity of the power supply control device 1, when the inverter unit 4 of the power supply control device 1 is oscillated, a counter electromotive voltage is likely to be generated in the armature winding 104 of the engine generator 101. On the other hand, if the external power supply of the power supply control device 1 of the present embodiment is a commercial power supply, the power supply control device 1 obtains a stable input voltage without being affected by the oscillation of the inverter unit 4 of the power supply control device 1. It is possible.

Subsequently, the inverter unit 4 of the power supply control device 1 is stopped. At this time, the load of the power supply control device 1 decreases, and the output voltage of the engine generator 101 temporarily increases. Similar to when the inverter unit 4 of the power supply control device 1 starts oscillating, the automatic voltage regulator 106 of the engine generator 101 adjusts the output voltage so that the output voltage becomes the set output voltage. At this time, the power supply control device 1 stores the voltage detected by the input voltage detection unit 8 in the first storage unit 9. Even when the engine generator 101 is connected to the power supply device 201, when the inverter unit 205 of the power supply device 201 stops oscillating, the output voltage of the engine generator 101 temporarily rises. Then, the output of the engine 102 is adjusted by the automatic voltage regulator 106, and the output voltage is adjusted to be the set voltage. Such an increase in voltage due to the stop of the inverter is shown at the beginning of t3 in FIG. 2 and at the beginning of t3 in FIG.

As described above, in the power supply control device 1 that does not have the smoothing capacitor of the present embodiment, the stability during oscillation of the inverter unit 4 varies greatly depending on whether the external power supply is an engine generator or a commercial power supply. Therefore, it is important for the power supply control device 1 to determine whether or not the external power supply connected to the power supply control device 1 of the present embodiment is an engine generator.

The power supply control device 1 of the present embodiment uses the voltage detected by the input voltage detection unit 8 in the first storage unit 9 while the inverter unit 4 is stopped, and the second storage unit 10 during oscillation of the inverter unit 4. Remember each. The control unit 11 compares the voltage (updated latest voltage) stored in the first storage unit 9 with the voltage stored in the second storage unit 10. When the voltage stored in the second storage unit 10 is higher than the voltage stored in the first storage unit 9 (updated latest voltage) by a predetermined value or more, the control unit 11 101 is specified. The predetermined value is preferably a voltage at which the output voltage of the engine generator 101 fluctuates due to the oscillation of the inverter unit 4, and is, for example, 10V to 50V.

As described above, according to the power supply control device 1 of the present embodiment, an external power supply can be specified. That is, the control unit 11 can compare the input voltage when the inverter unit 4 is stopped and the input voltage during oscillation of the inverter unit 4 to identify whether the external power source is a commercial power source or the engine generator 101.

In this embodiment, in FIG. 2, the waveform of the output voltage of the engine generator 101 is greatly varied every cycle in order to more clearly show the voltage variation. However, voltage fluctuations are not limited to one cycle, and may extend over several cycles.

In addition, since the power supply control device 1 is not provided with a smoothing capacitor between the first rectification unit 3 and the inverter unit 4, the power supply control device 1 can be reduced in size, weight, and cost.

In place of the input voltage detection unit 8, a voltage detector is provided between the first rectification unit 3 and the inverter unit 4, and the voltage during the stop of the inverter unit 4 is stored in the first storage unit 9 and the inverter unit. 4 may be stored in the second storage unit 10. The control unit 11 specifies the external power supply in the same manner as described above.

(Embodiment 2)
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted. Embodiment 2 will be described with reference to FIG. FIG. 4 is a diagram showing the configuration of the power supply control device 401 and the engine generator 101 in the present embodiment.

As shown in FIG. 4, the power supply control device 401 according to the present embodiment includes a first average voltage storage unit 14 in the first storage unit 9 and a second average voltage storage unit 15 in the second storage unit 10. Have The 1st average voltage memory | storage part 14 memorize | stores the average voltage (1st average voltage) of the voltage memorize | stored in the 1st memory | storage part 9, and the 2nd average voltage memory | storage part 15 is a 2nd memory | storage part. An average voltage (second average voltage) of the voltages stored in 10 is stored. The average voltage is an average of voltages for a certain period, and is calculated every certain period. For example, the average of voltages for 16 milliseconds is calculated every 10 microseconds. The first average voltage storage unit 14 stores the latest one of the first average voltages. In other words, the first average voltage storage unit 14 updates the first average voltage.

The first average voltage is the average voltage for the first period, and the second average voltage is the average voltage for the second period. At this time, the first period and the second period may have the same length or different lengths. Further, the first period and the second period are, for example, 16 milliseconds to 500 milliseconds. Further, the period for calculating the first average voltage may be the first period. Similarly, the period for calculating the second average voltage may be the second period.

4, the control unit 11 of the power supply control device 401 stores the first average voltage (updated latest average voltage) stored in the first average voltage storage unit 14 and the second average voltage storage. The second average voltage stored in the unit 15 is compared. When the second average voltage is higher than the first average voltage by a predetermined value or more (for example, 10 V to 50 V), the control unit 11 specifies that the external power source is the engine generator 101.

As in this embodiment, by averaging the input voltage, it is possible to prevent erroneous determination against noise and to stabilize the detection level of the input voltage. The average voltage may be a moving average voltage. The moving average voltage is an average voltage obtained from an average voltage of a plurality of unit times, and is updated every unit time.

(Embodiment 3)
In the third embodiment, the same components as those in the first embodiment and the second embodiment are denoted by the same reference numerals and detailed description thereof is omitted. Embodiment 3 will be described with reference to FIG. FIG. 5 is a diagram showing the configuration of the power supply control device 501 and the engine generator 101 in the present embodiment.

5, the power supply control device 501 includes an input voltage monitoring unit 16, an output current monitoring unit 17, an abnormality determination unit 18, and a display 19.

The difference of this embodiment from Embodiment 1 and Embodiment 2 is as follows. The power supply control device 501 includes an input voltage monitoring unit 16 that is connected to the input voltage detection unit 8 and monitors the input voltage detected by the input voltage detection unit 8. The power supply control device 501 includes an output current monitoring unit 17 that is connected between the control unit 11 and the output current detection unit 12 and monitors the output current detected by the output current detection unit 12. In addition, the power supply control device 501 has an abnormality determination unit 18 connected to the control unit 11, the input voltage monitoring unit 16, and the output current monitoring unit 17. The abnormality determination unit 18 determines whether or not the input voltage from the outside is abnormal based on the monitoring results of the input voltage monitoring unit 16 and the output current monitoring unit 17, and the output current to the outside is abnormal. It is determined whether or not. The power supply control device 501 is connected to the control unit 11 and has a display 19 for displaying an abnormality or the like.

Note that the operator can confirm the setting conditions, the output state (for example, output current, output voltage, etc.), etc., of the power supply control device 501 with the display 19. The indicator 19 is, for example, a liquid crystal panel, a 7 segment LED, an indicator lamp, or the like.

The abnormality determination unit 18 has a first stop condition and a second stop condition for determining occurrence of an abnormality. The first stop condition is used when the external power source is an engine generator, and the second stop condition is used when the external power source is a commercial power source.

The first stop condition is, for example, “the input voltage monitoring unit 16 detects that an input voltage equal to or higher than a predetermined voltage is input a predetermined number of times within a predetermined time” and “output current” In the monitoring unit 17, it is detected that an output current equal to or greater than a predetermined current has been generated for a predetermined number of times or more. When the power control device 501 is connected to the engine generator, when the first stop condition is satisfied, the power control device 501 determines that the input voltage from the external power source is abnormal.

As a specific example of the first stop condition, “in the input voltage monitoring unit 16, an input voltage of 210 V or more is detected five times or more per second”, and “in the output current monitoring unit 17, 500 A or more It is detected that the output current has continued for 10 milliseconds or more for 8 or more times. The predetermined voltage may be 300 to 400 V, or a voltage obtained by adding 100 V to 200 V to the input voltage. The predetermined time may be 10 milliseconds to 50 milliseconds.

The second stop condition is, for example, “the input voltage monitoring unit 16 detects an input voltage equal to or higher than a predetermined voltage within a predetermined time”, and “the output current monitoring unit 17 has a predetermined current. It is detected that the above output current continues for a predetermined time or more. When the power supply control device 501 is connected to a commercial power supply and the second stop condition is satisfied, the power supply control device 501 determines that the input voltage from the external power supply is abnormal.

As a specific example of the second stop condition, “the input voltage monitoring unit 16 detects an input voltage equal to or higher than the first input voltage +60 V in 300 milliseconds”, and “the output current monitoring unit 17 , It is detected that an output current of 500 A or more continues for 200 milliseconds or more.

Note that the first stop condition and the second stop condition are not limited to the above, and items may be added, items may be deleted, and threshold values may be changed. The first stop condition item and the second stop condition item do not necessarily match. The “item” in the present embodiment is “input voltage”, “output current”, “duration”, “number of occurrences”, and in addition, “input current”, “output voltage”, “occurrence interval” You may use. In addition, the “threshold value” in the present embodiment is a value determined in each “item”.

When the abnormality determination unit 18 determines an abnormality in the input voltage, the abnormality determination unit 18 detects an abnormality in the control unit 11 in order to protect the first rectification unit 3, the inverter unit 4, the second rectification unit 6, and the like from excessive voltage. Send a signal. Upon receiving the abnormal signal, the control unit 11 controls the drive unit 13 to stop the oscillation of the inverter unit 4. In addition, the control unit 11 that has received the abnormality signal transmits an abnormality display command to the display unit 19, and the display unit 19 displays the occurrence of the abnormality and notifies the operator of the occurrence of the abnormality. Further, the control unit 11 may stop the entire power supply control device 501.

According to the present embodiment, in addition to the effects of the first and second embodiments, it can be determined whether or not the input voltage to the power supply control device 501 is abnormal. Further, it is possible to protect the semiconductor and the like constituting the inverter unit 4 of the power supply control device 501.

In the present embodiment, the abnormality determination unit 18 may further include a third stop condition. The third stop condition is “the input voltage monitoring unit 16 detects an input voltage that damages a semiconductor or the like constituting the inverter unit 4”. This is a condition that does not relate to the type of external power supply, regardless of whether the inverter unit 4 oscillates or stops. When the third stop condition is satisfied, the abnormality determination unit 18 determines that the input voltage from the external power source is abnormal. Subsequent abnormality display, inverter stop, and power supply control device stop are the same as described above.

(Embodiment 4)
In the fourth embodiment, the same components as those in the third embodiment are denoted by the same reference numerals and detailed description thereof is omitted. The fourth embodiment will be described with reference to FIG. FIG. 6 is a diagram showing a configuration of the welding power source device 601 and the engine generator 101 in the present embodiment.

As shown in FIG. 6, the welding power supply apparatus 601 of the present embodiment is obtained by adding the output voltage detection unit 20 to the power supply control apparatus 501 shown in FIG. The output voltage detection unit 20 is connected to the output terminal 7a, the output terminal 7b, and the control unit 11, detects the output voltage between the output terminal 7a and the output terminal 7b, and transmits the output voltage to the control unit 11. The welding torch 23 is connected to the output terminal 7 a of the welding power source device 601, and the welding object 22 is connected to the output terminal 7 b of the welding power source device 601. Further, the welding torch 23 feeds the welding wire 21 fed by a feeding motor (not shown) to the welding position of the welding object 22. The output terminal 7 a is electrically connected to the welding wire 21, and the output terminal 7 b is electrically connected to the welding object 22. Then, output power (output voltage and output current) is supplied between the welding wire 21 and the welding object 22 to weld the welding object.

The welding power supply device 601 of the present embodiment is a consumable electrode system that feeds the welding wire 21 and performs welding while consuming the welding wire 21. Not limited to this, a non-consumable electrode system that supplies output power between the electrode fixed to the welding torch 23 and the welding object 22 may be used.

In welding by the consumable electrode method, welding is performed by repeating a short circuit state and an arc state between the welding wire 21 and the welding object 22. The control unit 11 determines whether the state is a short circuit state or an arc state from the output current detected by the output current detection unit 12 and the output voltage detected by the output voltage detection unit 20. And if it is a short circuit state, the inverter part 4 will be controlled based on an output current, and if it is an arc state, the inverter part 4 will be controlled based on an output voltage.

In welding by the consumable electrode method, the short-circuit state and the arc state are repeated between the welding wire 21 and the welding object 22, but the interval between the welding torch 23 and the welding object 22 (for example, 10 mm to 20 mm) is constant. In this case, the output fluctuation of the welding power source device 601 is stable. However, when the welding torch 23 and the welding object 22 are greatly approached during welding, the short-circuit state continues for a long time, and the tip end portion of the welding wire 21 is blown off when shifting to the next arc state. Thereby, an arc does not generate | occur | produce and the output current of the welding power supply device 601 falls instantaneously. In the welding power supply device 601 connected to the engine generator 101, when an instantaneous output voltage drop occurs, the output voltage from the engine generator 101 rises, and the controller 11 causes the external power source to be an engine generator. It can be identified.

Further, the first stop condition and the second stop condition may be optimally set in the welding power source apparatus 601. In welding in which the short circuit state and the arc state are repeated, the output current in the short circuit state is generally higher than the output current in the arc state. The first stop condition exemplified in the third embodiment is that the output current monitoring unit 17 detects that an output current of a predetermined current or more continues for a predetermined time or more has occurred for a predetermined number of times. May be set to a condition for monitoring the short-circuit state.

(Embodiment 5)
In the fifth embodiment, the same components as those in the first to fourth embodiments are denoted by the same reference numerals and detailed description thereof is omitted. The fifth embodiment will be described with reference to FIG. FIG. 7 is a diagram showing the configuration of the power supply control device 701 and the engine generator 101 in the present embodiment.

7, the power supply control device 701 has an output control unit 24.

The difference of this embodiment from Embodiments 1 to 4 is as follows. As the output from the power supply control device increases, the fluctuation in output also increases, and the power supply control device frequently stops abnormally. On the other hand, when the control unit 11 provided in the power supply control device 701 specifies the external power supply as the engine generator 101, the output control unit 24 lowers the output from the power supply control device 701 than the original rated output. Suppress to output. Thereby, the abnormal stop of the power supply control device 701 can be suppressed, and the power supply control device 701 can be operated continuously. A method for suppressing the output of the power supply control device 701 will be described more specifically below.

The output control unit 24 of the power supply control device 701 changes the output command sent from the control unit 11 to the drive unit 13 when the external power supply is the engine generator 101. Specifically, the inverter driving duty ratio of the inverter unit 4 is reduced. Thereby, the alternating current power from the inverter part 4 falls, and the output of the power supply control apparatus 701 falls. As the output of the power supply control device 701 decreases, the width of the output fluctuation also decreases, and the abnormal stop of the power supply control device 701 is reduced.

Hereinafter, an example of the operation of the output control unit 24 will be shown. When electric power with a DC current of 500 A is input from the first rectifying unit 3 to the inverter unit 4, and the control unit 11 transmits an output command for setting the inverter unit 4 to a duty ratio of 80% to the drive unit 13. explain. When the power supply control device does not have the output control unit 24, the inverter unit 4 outputs power with an AC current of 400A. At this time, the output control unit 24 of the power supply control device 701 of the present embodiment changes the output command for setting the duty ratio to 80% to the output command for setting the duty ratio to 60%. Thereby, the electric power with an alternating current of 300 A is output from the inverter unit 4, and the output electric power from the output terminals 7a and 7b of the power supply control device 701 is also reduced.

In this embodiment, the output control unit 24 is configured differently from the control unit 11, but the function of the output control unit 24 may be provided in the control unit 11. In the present embodiment, the output control unit 24 is provided between the control unit 11 and the drive unit 13, but may be provided between the drive unit 13 and the inverter unit 4. And the inverter unit 4 may be provided.

In the first to fifth embodiments, an example in which the engine generator 101 includes the automatic voltage regulator 106 has been described. However, even when the engine generator 101 does not include the automatic voltage regulator 106, the effect of the present disclosure is achieved.

Further, the abnormality determination unit 18 may include a first warning condition or a second warning condition in addition to the first stop condition or the second stop condition. The first warning condition is a condition for issuing a warning before the first stop condition is satisfied while the inverter unit 4 is stopped. Specifically, it is the same item as the first stop condition, and the threshold value of each item is smaller than that of the first stop condition. For example, “in the input voltage monitoring unit 16, an input voltage of 205 V or more is detected three times or more in one second” and “in the output current monitoring unit 17, an output current of 450 A or more continues for 7 milliseconds or more. It is detected that it has occurred 5 times or more. The first warning condition does not necessarily need to reduce the threshold values of all items of the first stop condition, and the number of items may be reduced. When the threshold value becomes smaller or the number of items decreases, the condition is easily satisfied. That is, the first warning condition is a condition that is easier to satisfy than the first stop condition. The second warning condition is a condition for issuing a warning before the second stop condition is satisfied during the oscillation of the inverter unit 4, and is a condition that is easier to satisfy than the second stop condition.

The abnormality determination unit 18 transmits a warning signal to the control unit 11 when the first warning condition and the second warning condition are satisfied. Thereby, the control part 11 can display a warning on the display 19, and can urge the operator to warn.

As described above, the power supply control device of the present disclosure specifies whether the external power supply is an engine generator. Furthermore, when the external power source is identified as an engine generator, the power control device of the present disclosure monitors the output current and the input voltage, and if the predetermined condition is exceeded, the input voltage of the power control device is abnormal. It is determined that And since the power supply control device of this indication stops an inverter part, it can prevent breakage of an inverter part and is industrially useful.

1, 401, 501, 701 Power control device 2 Input terminal 3 First rectifier 4 Inverter 5 Main transformer 6 Second rectifier 7a, 7b Output terminal 8 Input voltage detector 9 First storage 10 First 2 storage unit 11 control unit 12 output current detection unit 13 drive unit 14 first average voltage storage unit 15 second average voltage storage unit 16 input voltage monitoring unit 17 output current monitoring unit 18 abnormality determination unit 19 indicator 20 output Voltage detection unit 21 Welding wire 22 Welding object 23 Welding torch 24 Output control unit 101 Engine generator 102 Engine 103 Generator 104 Armature winding 105 Voltage setter 106 Automatic voltage regulator 107 Output terminal 201 Power supply device 202 Input terminal 203 Input side rectification unit 204 Smoothing capacitor 205 Inverter unit 206 Transformer 207 Output side rectification unit 208 a, 208b Output terminal 209 Inverter control unit 210 Power supply voltage detector 211 Current detector 212, 216 Voltage comparator 213 Maximum lower limit reference signal generator 214 Maximum upper limit reference signal generator 215 Inverter stop control unit 217 Rated lower limit reference signal generator 218 Rated upper limit reference signal generator 219 Alarm display 220 External power supply 601 Welding power supply

Claims (10)

An input terminal to which the input voltage from the power source is input;
An inverter connected to the input terminal for inverter control of the input voltage;
An output terminal connected to the inverter unit via a transformer and outputting an output current from the transformer;
An input voltage detection unit connected between the input terminal and the inverter unit for detecting the input voltage;
A first storage unit connected to the input voltage detection unit and storing a first input voltage detected by the input voltage detection unit while the inverter unit is stopped;
A second storage unit connected to the input voltage detection unit and storing a second input voltage detected by the input voltage detection unit during oscillation of the inverter unit;
A controller that is connected to the first storage unit and the second storage unit, compares the first input voltage with the second input voltage, and identifies whether the power source is a generator; With
When the difference between the first input voltage and the second input voltage is greater than a predetermined voltage, the control unit identifies the power source as a generator. The first input voltage is an average voltage for a first period of the input voltage;
The power supply control device according to claim 1, wherein the second input voltage is an average voltage for a second period of the input voltage. An input voltage monitoring unit connected to the input voltage detection unit;
An output current detection unit connected between the transformer and the output terminal and detecting the output current;
An output current monitoring unit connected to the output current detection unit;
An abnormality determining unit that is connected to the input voltage monitoring unit and the output current monitoring unit, and that determines an abnormality of the input voltage based on the input voltage and the output current;
The abnormality determination unit determines that the input voltage is abnormal when the first stop condition is satisfied when the power source is a generator,
The abnormality determining unit determines that the input voltage is abnormal when the second stop condition is satisfied when the power source is a commercial power source,
The power supply control device according to claim 1, wherein the abnormality determination unit outputs a stop signal for stopping the inverter to the control unit. The first stop condition is:
An input voltage greater than or equal to a first threshold voltage is input a first number of times during a first time; and
The power supply control device according to claim 3, wherein the number of times that the output current equal to or greater than the first threshold current continues for the second time or more is the second number or more. The first threshold voltage is 300V to 400V,
The first time is 1 second;
The first number is 5 times,
The first threshold current is 500 A;
The second time is 10-50 milliseconds;
The power supply control device according to claim 4, wherein the second number of times is eight. The second stop condition is:
The input voltage average for the third time is greater than or equal to the second threshold voltage; and
The power supply control device according to any one of claims 3 to 5, wherein the output current equal to or greater than the first threshold current is continued for a fourth time or more. The third time is 300 milliseconds;
The second threshold voltage is a voltage obtained by adding 60 V to the average of the input voltages,
The power supply control device according to claim 6, wherein the fourth time is 200 milliseconds. The output terminal has a first output terminal and a second output terminal;
The first output terminal is connected to an electrode, the second output terminal is connected to a welding object,
Welding is performed by repeating a short circuit state and an arc state between the electrode and the welding object,
The power supply control device according to any one of claims 3 to 7, wherein the output current is a short-circuit current in the short-circuit state. An output control unit provided between the inverter unit and the control unit;
The power supply control device according to any one of claims 1 to 8, wherein the output control unit changes an output command from the control unit to the inverter unit. A first rectifier connected between the input terminal and the inverter;
The power supply control device according to any one of claims 1 to 9, wherein an electrolytic capacitor does not exist between the first rectifying unit and the inverter unit.

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