RU2360347C1 - Device and method of emergency trip control for automatic switch - Google Patents

Abstract

FIELD: electric engineering.

SUBSTANCE: according to the invention, if current supplied to the customer is measured as overcurrent, the heat amount corresponding to the measured overcurrent is calculated and transmitted to the heat amount control unit before the supplied power is disconnected. The above-mentioned control unit continues to operate after de-energising using battery power. When power supply is restored via automatic switch, further overcurrent takes place. The residual amount of heat in electrical circuit is analysed based on the data stored in heat amount control unit and time elapsed. Finally, variable time of emergency trip delay for automatic switch is defined.

EFFECT: increased accuracy and easiness of device.

11 cl, 4 dwg

Description

Link to "related" applications

[001] This patent application is based on Korean patent applications No. 10-2006-0101066, filed October 17, 2006, and No. 10-2007-0095914, filed October 20, 2007, and claims to be priorities for these applications, the essence of which in its entirety by reference is incorporated into the present application.

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

[002] The present invention relates to an emergency shutdown control device for a circuit breaker, and more particularly, to an emergency shutdown control device and method for a circuit breaker in which heat amount control data is controlled by a heat quantity control unit that operates even when the power is turned off , and the amount of heat remaining in the electric circuit is analyzed on the basis of heat generation and elapsed time, which are recorded in the control unit la, after the occurred overcurrent, in order to determine trip delay time of the circuit breaker.

State of the art

[003] FIG. 1 is a circuit diagram of a conventional circuit breaker emergency trip control device.

[004] The emergency shutdown control device 10 includes a switch 11, a current sensor 12, a switch unit 13, a diode D1, a charging circuit 14, a voltage follower 15, and a microprocessor 16.

[005] The switch 11 is located in a line through which external power is supplied to the load, and is designed to turn off the power supplied to the consumer through the emergency shutdown coil 17.

[006] The current sensor 12 is located in a line between the switch 11 and the load and is designed to read the current supplied to the load. The current sensor 12 not only senses the current supplied to the load, but also receives the operating power of the circuit breaker from the line, and then transfers it to the consumer

[007] The switch 13 includes a transistor Q1. The transistor Q1 is unlocked in response to the output control signal from the microprocessor 16 for a predetermined trip delay time when the current measured by the current sensor 12 is an excessive current, and thus opens the circuit so that the current of the power supply with a voltage across the common collector (VCC) flows through a resistor.

[008] The diode D1 is designed to prevent current flowing in the opposite direction when the transistor Q1 is open.

[009] The charging circuit 14 includes a capacitor C1. The capacitor C1 is designed to charge to the charging voltage using the current of the power source flowing through the current circuit of the transistor Q1, and discharge to ground through the first resistor R1 when the switch 11 is open (i.e. when the voltage of the power source is not supplied through the transistor Q1) .

[010] The voltage follower 15 is designed to supply to the microprocessor 16 the residual voltage of the capacitor C1 of the charging circuit 14 when the open switch 11 closes.

[011] The microprocessor 16 is designed to control the switch 13 for a predetermined time delay emergency shutdown when the current measured by the current sensor 12 is excessive current, so that the charging circuit 14 is charged to the voltage of the power source; to control the emergency shutdown coil 17 in order to open the circuit breaker 11 after a predetermined emergency stop delay time has passed and to calculate the voltage remaining in the charging circuit 14 when the power supply resumes after the specified emergency shutdown delay time has passed and to estimate the residual heat in the line based on residual stress.

[012] In the conventional emergency shutdown control method constructed as described above, the microprocessor 16 controls the switch 13, including it, when the current measured by the current sensor 12 is excessive. As a result, the current of the power supply with voltage on the common collector flows through the switch 13, enters the capacitor C1 of the charging circuit 14, and the capacitor C1 begins to charge in accordance with the time constant determined by the first resistor R1.

[013] Then, the microprocessor 16 controls the emergency shutdown coil 17, opening the switch 11 after a predetermined emergency shutdown delay time.

[014] If the switch 11 opens, the capacitor C1 of the charging circuit 14 is no longer charged by the voltage of the power source and the charging voltage begins to gradually discharge through the first resistor R1.

[015] In this case, the microprocessor 16 of the circuit breaker operates on the basis of the power passing through the current sensor 12. When the current supplied to the load is an excessive current or leakage current, the microprocessor 16 automatically opens the circuit breaker 11 using the emergency shutdown coil 17 and does not work, since he no longer receives working food.

[016] Further, if the switch 11 is closed by the user and the operating power is again supplied to the circuit breaker, the microprocessor 16 determines whether excessive current is supplied to the load through the current sensor 12. If excessive current is detected again, the microprocessor 16 through the voltage follower 15 reads the voltage remaining in the capacitor C1.

[017] Based on this read value, the microprocessor 16 calculates the elapsed time after opening the switch 11, calculates the residual voltage based on the previously recorded data table in accordance with the calculated elapsed time, and based on the calculated residual voltage determines the current amount of heat remaining in the device and in line.

[018] In a prototype operating as described above, the residual voltage, elapsed time, and residual heat should be determined by calculating the slope of the voltage discharge curve stored in the capacitor. Accordingly, there are problems in that it is difficult to accurately calculate the residual amount of heat, and at a high cost, since it is necessary to use expensive accurate components.

[019] In addition, the capacitor in the charging circuit must remain unplugged for up to 30 minutes. Accordingly, there is a problem in that the cost of production increases because large components have to be used having very large capacitance and resistance values.

[020] In the case where the circuit that has been charged must be discharged due to a decrease in current, the circuit is complicated because additional components have to be introduced. Accordingly, there are problems in that the circuit is difficult to control from the point of view of both hardware and software and becomes complex.

SUMMARY OF THE INVENTION

[021] Accordingly, the present invention has been made in view of the aforementioned problems encountered in the known solutions, and an object of the present invention is to provide an apparatus and method for controlling an emergency shutdown of a circuit breaker in which the quantity control unit controls the quantity of heat heat that works even when the power is off; the residual amount of heat in the current transmission line is analyzed after the occurrence of excessive current based on the amount of heat and the elapsed time that are stored in the heat quantity control unit, and the emergency shutdown delay time of the circuit breaker is set variable, so that the switch is controlled quickly in accordance with the amount of heat, remaining in the consumer’s system, and as a result, a line blow and consumer damage due to subsequent excessive current may to be prevented.

[022] In order to achieve the above purpose, the emergency shutdown control device for the circuit breaker in accordance with the present invention comprises a circuit breaker arranged in a current line through which external power is supplied to the consumer and designed to shut off the power supplied to the consumer by the emergency shutdown coil; a current sensor located at the output end of the switch and designed to determine the amount of current supplied to the consumer; a heat quantity control unit for storing heat amount data received externally indicating the time when this heat amount data was transferred, so that this data can be stored by the power received from the battery during a power outage, and for transmitting data on an external request related to the amount of heat, which include stored data on the amount of heat, the time when this data was transferred, and the current time; and a microprocessor for calculating the amount of heat in the consumer system due to excessive current for a predetermined time of the emergency shutdown delay, for transmitting data on the calculated amount of heat to the heat quantity control unit, for controlling the emergency shutdown coil, to turn off the power supplied to the consumer when the current input the signal coming from the current sensor is excessive current to calculate the residual amount of heat based on the data related to the amount of heat that is recorded The heat value management unit, and to determine the trip delay time based on the calculated remaining heat value if the power supply is resumed, and then overcurrent is detected.

[023] The circuit breaker is preferably an air circuit breaker.

[024] The heat quantity control unit comprises a memory for storing data on the amount of heat transmitted from the microprocessor and the time when this heat amount data was transmitted; and a time controller for checking data on the amount of heat transferred from the microprocessor, and the time when these data on the amount of heat were transferred, and for recording data on the amount of heat and time in the memory, and for checking the data on the amount of heat and time stored in the memory when these data on the amount of heat were transferred, and the current time; and for transmitting data on the amount of heat, the specified time and the current time, when the microprocessor requests data related to the amount of heat.

[025] The time when this heat quantity data was transmitted is approximately the same as the time when the operating power was removed from the microprocessor. The current time is approximately the same as the time when excessive current was secondarily detected.

[026] The microprocessor controls the emergency shutdown coil to shut off the power supplied to the consumer when the calculated heat amount is more than a predetermined value.

[027] In order to achieve the aforementioned objective, the emergency shutdown control method for the circuit breaker according to the present invention, when the current detected by the microprocessor by the current sensor is excessive current, comprises the steps of: calculating the amount of heat in the consumer system caused by the excessive current for a given current emergency shutdown delay time; management of the calculated data on the amount of heat that must be recorded in the control unit of the amount of heat, and when the calculated data on the amount of heat exceeds a predetermined value, control the emergency shutdown coil to turn off the power supplied to the consumer; if the power is turned off, allowing the heat amount control unit to maintain information about the stored heat amount data and about the time when this heat amount data was transmitted using power supplied by the battery; if, after resuming the power supply, excessive current is detected again, then the microprocessor can receive data related to the amount of heat from the heat quantity control unit and calculate the residual amount of heat in the consumer system; and determining a variable predetermined emergency shutdown delay time based on the calculated residual heat.

BRIEF DESCRIPTION OF THE DRAWINGS

[028] Additional objectives and advantages of the invention can be better understood from the following detailed description in combination with the accompanying drawings, in which:

[029] FIG. 1 is a circuit diagram of a conventional emergency stop control device for a circuit breaker.

[030] FIG. 2 is a block diagram of an emergency shutdown control device for a circuit breaker in accordance with an embodiment of the present invention; and

[031] FIGS. 3a and 3b are flowcharts illustrating a method of controlling an emergency shutdown of a circuit breaker in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[032] An emergency shutdown control device and method for a circuit breaker in accordance with the present invention will now be described in detail in conjunction with specific embodiments of the invention with reference to FIGS. 2-3b.

[033] FIG. 2 is a block diagram of an emergency shutdown control device for a circuit breaker in accordance with an embodiment of the present invention. The circuit breaker 100 comprises an emergency shutdown control device having a circuit breaker 110, a current sensor 130, a heat quantity control unit 150, a microprocessor 170, and an emergency shutdown coil 190.

[034] The switch 110 is located in a line through which external power is supplied to the consumer, and is intended to turn off the power supplied to the consumer through the emergency shutdown coil 190.

[035] The current sensor 130 is located in line between the switch 110 and the consumer and is designed to perceive the current flowing to the consumer. The current sensor 130 not only determines the current supplied to the consumer, but also receives the operating power of the circuit breaker from the line, and then transfers it to the consumer.

[036] The heat quantity control unit 150 is designed to store data on the amount of heat received from the microprocessor 170, in accordance with the time when this data on the amount of heat was transferred, and during the absence of power supply saves the recorded data using the power supplied from batteries 160. The heat quantity control unit 150 is also intended for transmitting to the microprocessor 170 data related to the amount of heat, which includes data on the amount of heat stored upon request of the microprocessor 170 , the time when this heat quantity data was recorded, and the current time. The heat quantity control unit 150 can be implemented using a conventional unit - a real-time counter “RTC”.

[037] The heat quantity control unit 150 comprises a memory 155 and a time controller 151. Memory 155 is intended for storing data on the amount of heat received from the microprocessor 170 and the time when this data on the amount of heat was transmitted. The temporary controller 151 is designed to check data on the amount of heat transferred from the microprocessor 170, and the time when these data on the amount of heat were transferred, and to write them to memory 155. The temporary controller 151 is also used to check the data on the amount of heat stored in memory 155 heat and the time when this data about the amount of heat was transferred, and the current time when the microprocessor 170 requests data related to the amount of heat, and for transferring them to the microprocessor 170.

[038] The time controller 151 calculates and queries the time based on the clock signal generated by the crystal oscillator.

[039] When the current detected by the current sensor 130 is excessive current, the microprocessor 170 accumulates and calculates the amount of heat in the consumer system due to the excessive current for a predetermined emergency shutdown delay time and transmits the calculated heat amount data to the heat quantity control unit 150 Further, when the calculated heat quantity data exceeds a predetermined value, the microprocessor 170 controls the emergency shutdown coil 190 to turn off the power supplied to the consumer. If the switch 110 opens when the operating power is transmitted through the current sensor, and the power is therefore turned off, then the microprocessor 170 cannot work, because it does not receive working power through a current sensor 130.

[040] If external power is again supplied through the current sensor 130, then the microprocessor 170 again registers the current through the current sensor 130. If excessive current is detected again, the microprocessor 170 calculates the residual heat in the consumer system based on data related to the amount of heat stored in the control unit of the amount of heat 150, and based on the calculated residual amount of heat differently assigns a predetermined delay time emergency shutdown.

[041] In this case, the microprocessor 170 calculates the residual heat quantity by checking the elapsed time for the heat quantity data and sets the emergency shutdown delay time to be shorter the larger the residual heat quantity. A large residual amount of heat means that the consumer system is in an overheated state due to previous excessive current. Thus, to protect the consumer system, the microprocessor 170 controls the emergency shutdown coil 190 faster than the emergency shutdown delay time elapses when the residual heat is zero under normal conditions and opens the disconnector 110.

[042] The heat quantity control unit 150, upon request of the microprocessor 170, transmits data related to the amount of heat. Data related to the amount of heat includes data on the amount of heat, the time when the data on the amount of heat were transferred, and the current time.

[043] The time when the heat amount data was transferred from the microprocessor 170 to the heat quantity control unit 150 is approximately the same as the time when the operating power was removed from the microprocessor 170. The current time transmitted from the heat quantity control unit 150 to the microprocessor 170 is approximately the same as the time when excessive current is re-detected.

[044] In this case, the microprocessor 170 controls the emergency shutdown coil 190 only when the amount of heat in the consumer system, which is calculated during the emergency shutdown delay, exceeds a predetermined value, so that the switch 110 opens. The microprocessor 170 does not open the switch 110 when the data on the amount of heat in the consumer system is less than a predetermined value.

[045] For convenience of description, it was said above that the microprocessor 170 calculates the amount of heat when an excessive current is passed, and stores the calculated amount of heat in the heat quantity control unit 150. However, even when the current detected by the current sensor 130, does not exceed a predetermined excessive current, the microprocessor 170 can periodically calculate data on the amount of heat and store the calculated data on the amount of heat in the heat quantity control unit 150. Assuming that the excess current is 110% or more rated current, necessary to periodically store heat value data, as close to the nominal current value of 90 to 109% may also lead to deterioration of user characteristics or line.

[046] An emergency shutdown control device 100 in accordance with the present invention can be applied to a circuit breaker to which operating power is supplied via a current sensor 130 or via a current limiting inductor integrated in a current sensor, and can advantageously be applied to an air circuit breaker .

[047] The overall operation process of the emergency shutdown control device constructed as described above is described below with reference to the flowcharts shown in FIGS. 3a and 3b.

[048] First, the circuit breaker 100 operates in accordance with the operating power supplied through the current sensor 130. The current sensor 130 may include any type of sensors, such as a current transformer, Rogowski coil, or shunt.

[049] The microprocessor 170 of the circuit breaker 100 detects the current supplied to the consumer through the current sensor 130, and determines whether the detected current is excessive current (S1).

[050] If, as a result of the determination, it turns out that the detected current is an excessive current, then the microprocessor 170 accumulates and calculates in accordance with the excess current the amount of heat generated in the line and the consumer system during the time of the set emergency shutdown delay (S2). The amount of heat Q is determined by calculating (Q = I ² × T) the duration of the period (T; seconds) with current I during the delay time of the emergency shutdown.

[051] After the emergency shutdown delay time has elapsed, the microprocessor 170 transmits the calculated heat quantity data to the heat quantity control unit 150, and also determines whether the calculated heat quantity data exceeds a predetermined value (S3).

[052] If the emergency shutdown delay time expires and the heat amount data exceeds a predetermined value, the microprocessor 170 controls the emergency shutdown coil 190 by opening the switch 110 so that the power supplied to the consumer is turned off (S4). If the switch 110 opens, the microprocessor 170 does not receive operating power through the current sensor 130 and therefore it does not work.

[053] Meanwhile, the time controller 151 of the heat quantity control unit 150 receives the heat amount data from the microprocessor 170, checks the time when this heat amount data was transmitted, and stores the heat amount data and the time when this heat quantity data has been transmitted.

[054] If the switch 110 is opened and the operating power is turned off, the heat quantity control unit 150 receives power from the battery 160 (ie, from an auxiliary power source) and stores information on the amount of heat and time recorded in the memory 155 (S6) this heat quantity data has been transmitted.

[055] The heat quantity control unit 150 is designed to operate normally using power supplied through the current sensor 130, however, it will automatically switch to power from the battery 160 when the operating power is turned off.

[056] Subsequently, if the switch 110 is again closed by the user, the microprocessor 170 of the circuit breaker operates using the operating power supplied through the current sensor 130. The heat quantity control unit 150 also automatically operates using the operating power supplied through the current sensor 130.

[057] Then, the microprocessor 170 of the circuit breaker controls the current sensor 130 to detect the current supplied to the consumer again and determines whether the detected current is excessive current (S7).

[058] If, as a result of the determination, it turns out that the detected current is excessive current, then the microprocessor 170 sends a request to the heat quantity control unit 150 to transmit data stored therein related to the heat amount (S8).

[059] The temporary controller 151 of the heat quantity control unit 150 checks the data on the amount of heat and the time when these data were transmitted, stored in the memory 155, as well as the current time and transfers them to the microprocessor 170 (S9).

[060] The microprocessor 170 receives from the heat quantity control unit 150 data related to the amount of heat, including data on the amount of heat and the time when this data on the amount of heat was transmitted, and the current time, and calculates the residual amount of heat in the line and the consumer system (S10). The residual amount of heat is obtained by calculating the elapsed time of storage of data on the amount of heat based on the time of transmission of data on the amount of heat and the current time.

[061] In this case, the microprocessor 170 can determine the residual amount of heat by calculating the elapsed time for storing the amount of heat in the heat quantity control unit 150 and then searching for a value corresponding to the amount of heat and the elapsed time in the pre-recorded look-up table.

[062] The microprocessor 170 receives the residual heat as described above, and sets a short trip delay time when the residual heat is large. This is done in order to prevent deterioration or damage to the consumer system by establishing a shorter emergency shutdown delay time than during normal times (when the residual amount of heat is zero), i.e. by quickly opening the switch 110 due to the fact that the line and the consumer system are in a state of overheating due to previous excessive current.

[063] The microprocessor 170, based on the calculated residual heat, determines the predetermined emergency shutdown delay time differently (S11).

[064] Then, the microprocessor 170 calculates, in accordance with the excessive current, the amount of heat that is generated in the line and the consumer system for the obtained emergency shutdown delay time (S12).

[065] After the emergency shutdown delay time has passed, the microprocessor 170 transmits the calculated heat amount data to the heat quantity control unit 150, and also determines whether the calculated heat amount exceeds a predetermined value (S13).

[066] If the emergency shutdown delay time has expired and it is determined that the amount of heat exceeds a predetermined value, the microprocessor 170 controls the emergency shutdown coil 190 to open the switch 110, so that the power supplied to the consumer is turned off (S14).

[067] The temporary controller 151 of the heat quantity control unit 150 receives data on the amount of heat from the microprocessor 170, checks the time when this data on the amount of heat was transmitted, and stores in the memory 155 the data on the amount of heat and the time when this data on the amount of heat were transferred.

[068] If the switch 110 opens and the operating power is turned off, the heat quantity control unit 150 receives power from the battery 160 and stores information on the heat quantity and the time when the heat quantity data was transmitted recorded in the memory 155 (S15).

[069] Subsequently, if the power supply is resumed and excessive current is detected, the microprocessor 170 re-executes this process, obtaining data related to the amount of heat from the heat quantity control unit 150, calculating the residual amount of heat in the consumer system and determining a different predetermined emergency delay time shutdowns based on the calculated residual heat (S7-S15).

[070] As described above, according to the emergency shutdown control method in accordance with the present invention, the heat quantity control unit 150, for example, the RTC real-time counter, reproduces data on the amount of heat in the line and the consumer and the time elapsed after the occurrence of excessive current . Accordingly, the residual heat can be measured more accurately, the error that occurs when the device is implemented as an existing analog device can be minimized, the circuit can be simplified and in emergency conditions with subsequent excessive current, more reliable and accurate can be realized Work.

[071] Although the present invention has been described with reference to specific illustrated embodiments, it is not limited to these embodiments, but only to the attached patent claims. It is understood that those skilled in the art can modify or modify embodiments without going beyond the letter and spirit of the present invention.

Claims (11)

1. An emergency shutdown control device for a circuit breaker, comprising: a circuit breaker located in a current circuit through which external power is supplied to a consumer and intended to shut off power supplied to a consumer by an emergency shutdown coil; a current sensor located on the output side of the switch and designed to detect the current supplied to the load; a heat quantity control unit for storing heat amount data received externally with reference to the time when this heat amount data was transferred, and when the power is turned off, these stored data can be saved by receiving power from the battery, and for transmitting data on an external request, related to the amount of heat, including stored data on the amount of heat, the time at which this data on the amount of heat was transmitted, and the current time; and a microprocessor for calculating the amount of heat in the consumer system caused by excessive current during the time of the set emergency shutdown delay, for transmitting the calculated data on the amount of heat to the heat quantity control unit and for controlling the emergency shutdown coil to shut off the power supplied to the consumer when passing through current sensor current is excessive current, and to calculate the residual amount of heat based on data related to the amount of heat stored in the control unit Lenia amount of heat, and to determine the trip delay time based on the calculated remaining heat value if the power supply is resumed and then overcurrent is detected again. 2. The emergency shutdown control device according to claim 1, wherein the circuit breaker is an air circuit breaker. 3. The emergency shutdown control device according to claim 1, wherein the heat quantity control unit comprises: a memory for storing data on the amount of heat transmitted from the microprocessor, and the time when these data on the amount of heat were transferred; and a time controller: for checking data on the amount of heat transferred from the microprocessor, and the time when these data on the amount of heat were transferred and for storing the specified data on the amount of heat and time in the memory; to check the stored data on the amount of heat and the time when these data on the amount of heat were transferred, and the current time; and for transmitting said data on the amount of heat, time and current time when the microprocessor requests data related to the amount of heat. 4. The emergency shutdown control device according to any one of claims 1 to 3, in which: the time when the data on the amount of heat was transmitted is approximately the same with the time the microprocessor was powered off, and the current time is approximately the same with the time for over-current re-registration. 5. The emergency shutdown control device according to any one of claims 1 to 3, in which the microprocessor calculates the residual amount of heat by checking the elapsed time for data on the amount of heat. 6. The emergency shutdown control device according to any one of claims 1 to 3, in which the microprocessor controls the emergency shutdown coil to shut off the power supplied to the consumer when the calculated heat quantity data exceeds a predetermined value. 7. A method of controlling an emergency shutdown for a circuit breaker, comprising the steps of: when the current detected by the microprocessor by the current sensor is excessive current, calculating an amount of heat in the user system caused by the excessive current for a predetermined emergency shutdown delay time; management of the calculated data on the amount of heat that must be stored in the control unit of the amount of heat, and when the calculated data on the amount of heat exceeds a predetermined value, control the emergency shutdown coil to turn off the power supplied to the consumer; if the power is turned off, then providing the heat amount control unit with the ability to store information about the stored heat amount data and the time when this heat amount data was transmitted using power supplied by the battery; if after the disconnected power is restored, excessive current is registered again, then ensuring that the microprocessor receives from the control unit the amount of heat of the data related to the amount of heat and calculates the residual amount of heat in the user system; and assign, based on the calculated residual amount of heat, an adjustable predetermined emergency shutdown delay time. 8. The emergency shutdown control method according to claim 7, wherein when said power is turned off, the power supplied to the microprocessor is also turned off. 9. The emergency shutdown control method of claim 7, wherein the data related to the amount of heat includes data on the amount of heat, the time when these data on the amount of heat were transmitted, and the current time. 10. The method of controlling the emergency shutdown according to any one of claims 7 to 9, in which the microprocessor determines the residual amount of heat by calculating the time that is obtained for the data on the amount of heat stored in the heat quantity control unit. 11. The method of controlling the emergency shutdown according to any one of claims 7 to 9, in which the microprocessor calculates the elapsed time that is obtained for the heat quantity data stored in the heat quantity control unit, and then finds the residual heat quantity by searching for a value corresponding to the heat quantity and elapsed time through a pre-recorded lookup table.

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