CN108051706B - Fault identification method and system for automatic standby power supply switching device - Google Patents

Abstract

A method and system for identifying faults of an automatic switching-in device of a backup power supply relate to a method and a system for automatically switching on the backup power supply of a substation. The method includes the following steps: centrally install a merging unit intelligent terminal integrated device on the bus tie and the incoming line, collect the voltage of the bus bar and the incoming line, the current of the incoming line and the segment, and the switch position, and send the optical signal message. To the standby self-switching device, at the same time, it receives and executes the command from the standby self-switching to control the operation of the circuit breaker; the standby self-switching device automatically judges its current direction as the criterion for fault location; when the standby self-switching start conditions are met, the standby self-switching The device judges whether there is a bus fault or a transformer fault, and then executes the standby self-switching logic according to the strategy to automatically identify the fault type. The system includes a backup power supply automatic input device, a merging unit intelligent terminal integration device, a direction monitoring unit for real-time monitoring of the direction and magnitude of line current, and a fault judgment and positioning monitoring unit. The invention can effectively improve the power supply reliability of the power network and the stability of the power grid operation.

Description

Fault identification method and system for automatic power-on device of backup power supply

technical field

The invention relates to a method and system for automatic switching on of backup power in a substation, in particular to a method and system for automatic switching on of backup power with a voltage level of 110 kV without busbar protection, which requires automatic switching on and automatic identification of fault types and executes different logics.

Background technique

With the rapid development of social economy, power users have higher and higher requirements for the reliability of power supply and the stability of power grid operation.

At present, the standby self-switching device in the intelligent substation can automatically detect the operation mode of the substation and complete the automatic switching logic of the standby power supply in the station, which can greatly improve the power supply reliability of the power grid, and it occupies an important position in the power grid automation system. However, the current mainstream 110kV substations will not be equipped with busbar protection alone. In this way, when there is a busbar fault, the backup protection action of the transformer or line will be used to cut it off. The risk of failure; when the transformer operates, the previous mainstream standby automatic switching failed to distinguish the action type, and the standby automatic switching was directly blocked, and there was a situation where the loss partially met. At present, there is no standby power automatic switching device that can judge the fault type and implement different strategies according to the relevant electrical quantities and switching quantities.

SUMMARY OF THE INVENTION

One of the objectives of the present invention is to provide a fault identification method for an automatic power-on device of a backup power source, which can quickly and accurately determine the fault type in an intelligent substation, and realize and automatically input the backup power source according to the response strategy.

One of the objectives of the present invention can be achieved by designing a fault identification method for an automatic input device of a backup power supply, comprising the following steps:

A. The integrated device of merging unit intelligent terminal is centrally installed on the bus tie and incoming line, collects the busbar voltage, incoming line voltage, incoming line current, segment current and the position of incoming line and segment switch, and transmits the message optical signal. To the standby self-switching device, at the same time receive and execute the tripping and closing commands from the standby self-switching, and control the operation of the circuit breaker;

B. The standby self-switching device automatically judges the current direction according to the relationship between the bus voltage and the incoming line current from the intelligent terminal integrated device of the line merging unit, as the criterion for fault location;

The relationship between the busbar voltage and the incoming line current stipulates that the flow from the line to the busbar is the positive direction, and the directional element adopts a 90° connection. The forward direction action equation is:

和

分别代表90°接线方式中相对应的进线电流和母线电压；where:

and

Represent the corresponding incoming current and bus voltage in the 90° connection mode;

When the device judges the positive direction and the current value is greater than the fault current threshold, it means that the fault point is below the current transformer of the circuit breaker; if it is the opposite direction, it is a line fault;

C. When the busbar voltage does not meet the voltage condition, and at the same time meets the backup automatic switching start conditions, the backup automatic switching device judges whether there is a busbar fault or transformer fault according to the relationship between the relevant AC quantity and electrical quantity, and then executes different strategies according to different strategies. Equipped with automatic switching logic to automatically identify fault types.

Further, in the bus tie standby mode, charge when the following conditions are met: 1a, the bus tie switch is in the open state; 1b, the incoming line switch is in the closed state; 1c, the busbar voltage is higher than the busbar voltage setting value;

Discharge when any one of the following conditions is met: 2a, the self-switching input of the locked incoming line is set to 1; 2b, the switch of one of the incoming lines is manually jumped by remote control or on-site; 2c, the transformer action signal is set to 1; 2d, the bus tie switch Closed; 2e, the voltage of the two sections of the bus does not meet the voltage time greater than 15s; 2f, the maintenance status of the intelligent terminal integrated device of the incoming line merging unit is inconsistent with the maintenance status of the standby self-switching device; 2g, the integrated device of the intelligent terminal of the bus-joint merging unit The maintenance status is inconsistent with the maintenance status of the standby automatic switching device; 2h, the bus tie standby automatic switching soft pressure plate or the control word is not put in; 2i, the incoming line switch refuses to trip or the bus tie switch refuses to close;

When the standby automatic switching device receives the action signal from the transformer protection device, it is considered that there is a fault in the corresponding transformer protection at this time, and the standby automatic switching device should discharge directly;

If the current flowing through the incoming line is greater than the set fault current threshold, and judged to be in the positive direction according to the direction criterion, the device determines that the corresponding bus is faulty; first cut off the incoming line switch, and close the bus tie switch; after closing the bus tie switch , if the corresponding bus fault is a transient fault, the fault has been eliminated at this time, and the system can operate normally; if the corresponding bus fault is a permanent fault, after closing the bus tie switch, the fault current through the bus tie CT is greater than the post-acceleration fixed value , at this time, start the post-acceleration function of the bus tie, cut off the bus tie switch, and isolate the fault point;

If the current flowing through the incoming line is less than the set fault current threshold, or judged to be the opposite direction according to the direction criterion, the device judges that the line is faulty, first cut off the corresponding incoming line switch, and close the bus tie switch to ensure that the entire station does not lose voltage.

Further, in the incoming line standby self-throwing mode, charge when the following conditions are met: 3a, the incoming line switch is in the open state; 3b, the other incoming line switch is in the closed state; 3c, the busbar voltage is higher than the busbar There is a voltage setting; 3d, the bus tie switch is in the closed state; 3e, when the incoming line voltage control word is checked, the incoming line extraction voltage is higher than the incoming line voltage setting value;

Discharge when any of the following conditions are met: 4a, the incoming line is locked and set to 1; 4b, the other incoming line switch is manually opened by remote control or on-site; 4c, the action signal of the transformer is set to 1; 4d, the incoming line The switch is closed; 4e. When checking that the incoming line voltage control word is turned on, the incoming line extraction voltage does not meet the voltage time greater than 15s; 4f. The incoming line merging unit intelligent terminal integrated device maintenance status and the standby self-switching device maintenance status Inconsistent; 4g, the maintenance status of the intelligent terminal integrated device of the bus-unit merging unit is inconsistent with the maintenance status of the standby self-throwing device; 4h, the incoming line standby self-throwing soft pressure plate or control word is not put in; 4i, another incoming line switch refuses to trip or The incoming switch refuses to close or the bus tie switch refuses to trip;

When the standby automatic switching device receives the action signal from the 1# transformer protection device, it is considered that there is a fault in the 1# transformer protection at this time, and the standby automatic switching device starts at this time, jumps off the incoming line "1" switch and the bus tie switch, and then Close the incoming line "2" switch;

When the standby automatic switching device receives the action signal from the 2# transformer protection device, it is considered that the 2# transformer protection is faulty at this time, and the standby automatic switching device should discharge directly to prevent the switch from closing in the fault and affect the system stability;

If the current flowing through the incoming line "1" is greater than the set fault current threshold, and judged as positive direction according to the direction criterion, the device judges that the busbar is faulty, first cut off the bus tie switch, and after the bus tie switch is cut off, it flows through the incoming line "1" ” disappears, indicating that the fault point is on the II bus and has been removed; if the current flowing through the incoming line “1” still exists, it means that the fault point is on the I bus, and the device cuts off the incoming line “1” switch and closes the The upper incoming line "2" switch ensures that the II bus load is not cut off;

If the current flowing through the incoming line "1" is less than the set fault current threshold, or judged to be the opposite direction according to the direction criterion, the device judges that the line is faulty, first cut off the incoming line "1" switch, and close the incoming line "2" switch , to ensure that the entire station does not lose voltage.

One of the purposes of the present invention can be achieved by designing a fault identification system for an automatic power-on device for backup power, including an automatic power-on device for backup power, an integrated device for merging unit intelligent terminals, a direction monitoring unit for real-time monitoring of the direction and magnitude of line current, and a fault detection unit. Judgment and positioning monitoring unit,

The backup power supply automatic input device automatically judges the fault condition according to the electrical quantity and switch quantity information provided by the intelligent terminal integrated device of the merging unit, and executes the logic corresponding to the fault type according to the fault type to ensure the reliability and stability of the power supply system;

The intelligent terminal integrated device of the merging unit sends out an optical signal according to the analog sampling value collected by the collector, the switch position of the circuit breaker and the synchronization signal of the substation, and at the same time accepts the control command from the automatic input device of the standby power supply to operate the circuit breaker mechanism;

A direction monitoring unit that monitors the direction and magnitude of the line current in real time, and judges the direction and magnitude of the current according to the received bus voltage and line current;

The fault judgment and location monitoring unit judges the fault according to the monitoring results of the direction monitoring unit that monitors the direction and magnitude of the line current in real time, and locates the fault point by switching the switch.

The invention adopts the detection unit in the substation control system that can detect the busbar voltage and incoming current direction of the station in real time, monitors the electrical quantity of the system, the circuit breaker switch information and the action signals of other protection devices in real time, and transmits it to the backup device in real time as an optical signal. The structure of the merging unit intelligent terminal integrated unit that simultaneously accepts the self-switching command from the standby and self-switching device enables the standby self-switching device system of the present invention to effectively improve the power supply reliability of the power network and the stability of the power grid operation. It can be used for self-switching of conventional backup, and can also be used as a self-switching backup with fault identification function.

Description of drawings

1 is a schematic diagram of a network architecture of a preferred embodiment of the present invention;

Fig. 2 is the logic diagram of the self-throwing action of the incoming line "2" of the preferred embodiment of the present invention;

FIG. 3 is a logic diagram of the self-throwing action of the segmented device according to the preferred embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the embodiments.

The present invention is a backup device of an intelligent standby power automatic switching device (also known as a standby automatic switching device) designed for the main wiring of a substation with a single busbar, a single busbar with a bypass, a single bus section and a single bus section with a bypass. self-injection method. The invention can judge the fault type of the power system according to the electrical quantity information such as the binary input quantity and the AC quantity of the device, and execute different logics according to different fault types.

A method for identifying faults of a backup power supply automatic input device, comprising the following steps:

A. Centrally install the integrated unit intelligent terminal integrated device on the bus tie and incoming line, collect the bus voltage, incoming line voltage, incoming line current, segment current and the position of incoming line and segment switch, and use IEC61850 message light The signal is sent to the standby automatic switching device, and at the same time, the trip and closing commands from the standby automatic switching device are received and executed, and the operation of the circuit breaker is controlled;

B. The standby self-switching device automatically judges the current direction according to the relationship between the bus voltage and the incoming line current from the intelligent terminal integrated device of the line merging unit, as the criterion for fault location;

C. When the busbar voltage does not meet the voltage condition, and at the same time meets the backup automatic switching start conditions, the backup automatic switching device judges whether there is a busbar fault or transformer fault according to the relationship between the relevant AC quantity and electrical quantity, and then executes different strategies according to different strategies. Equipped with automatic switching logic to automatically identify fault types to ensure reliable and stable power supply.

The automatic switching device automatically judges the current direction according to the relationship between the bus voltage and the incoming current from the intelligent terminal integrated device of the line merging unit, as the criterion for fault location. The criterion is as follows: The relationship between the bus voltage and incoming current , it is stipulated that the flow from the line to the bus is the positive direction, and the directional element adopts a 90° connection (Ia→Ubc/Ib→Uca/Ic→Uab), and the action equation in the positive direction is:

和

分别代表90°接线方式中相对应的电流和电压量。where:

and

Represent the corresponding current and voltage in the 90° wiring mode.

When the device judges that it is in the positive direction and the current value is greater than the fault current threshold, it means that the fault point is below the current transformer of the circuit breaker; if it is the opposite direction, it is a line fault. The fault identification and direction identification function device makes real-time judgment to ensure the reliability and integrity of the data and eliminate the risk of misjudgment and misjudgment.

The implementation process of the present invention is as follows:

1. As shown in Figure 1 and Figure 2, take the input line "2" as an example.

When it is in the incoming line standby mode, charge when the following conditions are met: 3a, the incoming line switch (incoming line 2 switch) is in the open state; 3b, the other incoming line switch (incoming line 1 switch) is in the closed state 3c, the bus voltage is higher than the bus voltage setting value; 3d, the bus tie switch is in the closed state; 3e, when the incoming line (incoming line "2") voltage control word is checked, the incoming line (incoming line "2") is turned on. "2") The extraction voltage is higher than the incoming line voltage setting value.

Discharge when any one of the following conditions is met: 4a. The incoming line is locked and set to 1; #Transformer) action signal is set to 1; 4d, the incoming line switch (incoming line "2" switch) is closed; 4e, when the incoming line (incoming line "2") voltage control word is checked, the incoming line (incoming line "2") is turned on. Line "2") The extraction voltage does not meet the voltage-holding time greater than 15s; 4f, the incoming line (incoming line 1 or incoming line 2) merge unit intelligent terminal integrated device maintenance status is inconsistent with the standby self-switching device maintenance status; 4g, the bus union The maintenance status of the integrated device of the intelligent terminal of the parallel unit is inconsistent with the maintenance status of the standby self-throwing device; 4h, the incoming line (incoming line "2") has the self-throwing soft pressure plate or the control word not put in; 4i, another incoming line switch (incoming line "2") Line "1" switch) refuses to trip or the incoming line switch (incoming line "2" switch) refuses to close or the bus tie switch refuses to trip.

Action logic is divided into: 1# main transformer failure, 2# main transformer failure, I bus failure, II bus failure, incoming line "2" line failure, etc. The device can implement different strategies according to various situations.

When the standby automatic switching device receives the action signal from the 1# transformer protection device, it is considered that there is a fault in the 1# transformer protection at this time, and the standby automatic switching device starts at this time, jumps off the incoming line "1" switch and the bus tie switch, and then Close the incoming line "2" switch. When the 1# transformer fails, the standby self-switching device receives the GOOSE action signal from the 1# main transformer protection at this time, and judges whether the I bus voltage and the II bus voltage are both lower than the bus no-voltage fixed value. If the voltage of the two busbars is lower than the busbar no-voltage setting, the device will start automatically. After the setting delay, the “1” switch and the bus tie switch of the incoming line will be tripped. After the "1" switch and the bus tie switch are both tripped, after a set value for a period of time, the command to close the "2" switch of the incoming line is automatically issued; confirm that the "2" switch of the incoming line has been closed, and send a report of the completion of the standby automatic switching. During the action of backup and automatic switching, if any switch refuses to jump or close, the operation process of automatic switching of backup will be stopped, and a report of failure of automatic switching of backup will be issued. At this time, the fault is isolated to ensure that the II bus load is not removed, and the reliability of the power supply is improved.

When the standby automatic switching device receives the action signal from the 2# transformer protection device, it is considered that there is a fault in the 2# transformer protection at this time, and the standby automatic switching device should discharge directly to prevent the switch from closing in failure and affecting the system stability. When the 2# transformer fails, when the 2# transformer fails, the standby self-switching device receives the GOOSE action signal from the 2# main transformer protection, and the standby self-switching directly discharges at this time, and cannot operate, because if the incoming line is closed "2" will be directly connected to the fault, causing an impact on the power system.

If the current flowing through the incoming line "1" is greater than the set fault current threshold, and judged as positive direction according to the direction criterion, the device judges that the busbar is faulty, first cut off the bus tie switch, and after the bus tie switch is cut off, it flows through the incoming line "1" ” disappears, indicating that the fault point is on the II bus and has been removed; if the current flowing through the incoming line “1” still exists, it means that the fault point is on the I bus, and the device cuts off the incoming line “1” switch and closes the The upper incoming line "2" switch ensures that the II bus load is not cut off. When the II bus fails, the I bus voltage and the II bus voltage will both be lower than the bus no-voltage fixed value, and the “1” direction criterion of the incoming line will judge the positive direction at this time, that is, the current flows from the line to the bus. The standby self-switching device judges that the bus is faulty. After setting the time-delay bus tie switch, the device sends out an action signal, and at the same time prepares for self-feeding; after confirming that the bus tie switch is tripped, if the current flowing through the incoming line "1" is lower than the set value of the fault current, it means that the fault is in II at this time. On the bus, and has been isolated, the standby automatic switching device sends a report that the standby automatic switching is completed. During the action of backup and automatic transfer, the bus tie switch refuses to trip, suspends the operation of backup and automatic transfer, and issues a report of failure of backup and automatic transfer.

When the I bus is faulty, the I bus voltage and the II bus voltage will both be lower than the bus no-voltage fixed value, and the “1” direction criterion of the incoming line will judge that it is the positive direction at this time, that is, the current flows from the line to the bus. The standby self-switching device judges that the bus is faulty. After setting the time-delay bus tie switch, the device sends out an action signal, and at the same time prepares for self-feeding; after confirming that the bus tie switch is tripped, if the current flowing through the incoming line "1" is still greater than the set value of the fault current, it means that the fault is at I. If the fault still exists on the bus, after the setting delay, the switch "1" of the incoming line is tripped, and the device sends an action signal; after confirming that the switch of "1" of the incoming line is tripped, after a set value for a period of time, it will automatically send out the "2" of the incoming line ” switch command, the standby auto-throwing device will issue a report that the standby auto-throwing is completed. In the process of the automatic switching operation, if any switch refuses to jump or close, the operation process of the automatic switching will be stopped, the operation process of the automatic switching will be stopped, and a report of the failure of the switching will be issued.

If the current flowing through the incoming line "1" is less than the set fault current threshold, or judged to be the opposite direction according to the direction criterion, the device judges that the line is faulty, first cut off the incoming line "1" switch, and close the incoming line "2" switch , to ensure that the entire station does not lose voltage. When the line fails, the I bus voltage and the II bus voltage will both be lower than the bus no-voltage fixed value, and the incoming line "1" direction criterion will judge the reverse direction at this time, that is, the current flows from the bus to the line. At this time, the equipment will jump off the "1" switch of the incoming line after setting the delay time, and the device will send an action signal, and at the same time, the equipment will be powered on by itself; after confirming that the "1" switch of the incoming line has tripped, it will automatically send out the closing input after a set value for a period of time. Line "2" switch command; confirm that the incoming line "2" switch has been closed, and issue a report of the completion of automatic switching. During the action of backup and automatic switching, if any switch refuses to jump or close, the operation process of automatic switching of backup will be stopped, and a report of failure of automatic switching of backup will be issued.

2. As shown in Figure 1 and Figure 3, take the self-injection of the parent-connector as an example:

When it is in the self-switching mode of the bus tie backup, it will be charged when the following conditions are met: 1a, the bus tie switch is in the open state; 1b, the incoming line switch (the incoming line "1" switch, the incoming line "2" switch) is in the closed state Status; 1c, the bus voltage is higher than the bus voltage fixed value.

Discharge when any of the following conditions are met: 2a. The incoming line is locked and set to 1; ); 2c, the action signal of one of the incoming transformers (1# transformer or 2# transformer) is set to 1; 2d, the bus tie switch is closed; 2e, the voltage of the two busbars does not meet the voltage duration greater than 15s; 2f, the incoming line (Incoming line 1 or incoming line 2) The inspection status of the integrated device of the intelligent terminal of the merging unit is inconsistent with the inspection state of the standby self-injection device; 2g, The inspection state of the integrated device of the intelligent terminal of the main unit merging unit is inconsistent with the inspection state of the standby self-injection device; 2h , The bus tie is equipped with a self-switching soft pressure plate or the control word is not put into use; 2i, the incoming line switch (incoming line "1" switch or incoming line "2" switch) refuses to jump or the bus tie switch refuses to close.

Action logic is divided into: 1# main transformer failure, 2# main transformer failure, I bus failure, II bus failure, incoming line "2" line failure, etc. The device can implement different strategies according to various situations.

When the standby automatic switching device receives the action signal from the transformer protection device, it is considered that there is a fault in the corresponding transformer protection at this time, and the standby automatic switching device should discharge directly to prevent the switch from closing on the fault and affect the system stability. When the 1# transformer fails or the 2# main transformer fails, when the transformer fails, the standby automatic switching device receives the GOOSE action signal from the 1# main transformer protection or the 2# main transformer protection. Discharge, can not act, because if the line "2" is closed, it will be directly connected to the fault, which will cause an impact on the power system.

When the I bus is faulty, the I bus voltage will be lower than the bus no-voltage fixed value, and the “1” direction criterion of the incoming line will judge the positive direction at this time, that is, the current flows from the line to the bus. The standby self-switching device judges that the bus is faulty. After setting the "1" switch of the incoming line, the device sends out an action signal, and at the same time prepares for self-discharging; after confirming that the "1" switch of the incoming line is tripped, the command to close the bus tie is automatically issued after a set value for a period of time to determine the bus tie. When the switch is closed, the standby auto-throwing device sends a report that the standby auto-throwing is completed. In the process of the automatic switching operation, if any switch refuses to jump or close, the operation process of the automatic switching will be stopped, the operation process of the automatic switching will be stopped, and a report of the failure of the switching will be issued. After closing the bus tie switch, if the I bus fault is a transient fault, the fault has been eliminated at this time and the system can operate normally; if the I bus fault is a permanent fault, after closing the bus tie switch, after the fault of the bus tie CT When the current is greater than the post-acceleration setting value, the post-acceleration function of the bus tie is activated at this time, and the bus tie switch is cut off to isolate the fault point.

When the II bus fails, the II bus voltage will be lower than the bus no-voltage setting, and the incoming line "2" direction criterion will judge that it is the positive direction at this time, that is, the current flows from the line to the bus. The standby self-switching device judges that the bus is faulty. After the setting delay of the incoming line "2" switch, the device sends out an action signal, and at the same time prepares for self-feeding power; after confirming that the incoming line "2" switch is tripped, after a period of time, the command to close the bus tie switch is automatically issued to determine the bus tie. When the switch is closed, the standby auto-throwing device sends a report that the standby auto-throwing is completed. In the process of the automatic switching operation, if any switch refuses to jump or close, the operation process of the automatic switching will be stopped, the operation process of the automatic switching will be stopped, and a report of the failure of the switching will be issued. After closing the bus tie switch, if the II bus fault is a transient fault, the fault has been eliminated at this time and the system can run normally; if the II bus fault is a permanent fault, after closing the bus tie switch, after the bus tie CT fault When the current is greater than the post-acceleration setting value, the post-acceleration function of the bus tie is activated at this time, and the bus tie switch is cut off to isolate the fault point.

Line fault, when the line fails, the I bus voltage will be lower than the bus no-voltage fixed value, and the "1" direction criterion of the incoming line will judge that it is the opposite direction at this time, that is, the current flows from the bus to the line. After setting delay of auto-throwing, the switch of incoming line "1" is tripped, and the device sends out an action signal, and at the same time prepares for self-throwing power; after confirming that the "1" switch of incoming line is tripped, after a set value for a period of time, the command for closing the bus tie switch is automatically issued. ; Confirm that the bus tie breaker has been closed, and issue a report of the completion of automatic switching. During the action of backup and automatic switching, if any switch refuses to jump or close, the operation process of automatic switching of backup will be stopped, and a report of failure of automatic switching of backup will be issued.

The above-mentioned backup and self-switching method is an adaptive method, and the device can judge by itself depending on the position of the corresponding circuit breaker, without manual switching.

As shown in Figure 1, a fault identification system for automatic input device of backup power supply, including automatic input device of backup power supply, integrated device of intelligent terminal of merging unit, direction monitoring unit for real-time monitoring of the direction and magnitude of line current, fault judgment and positioning monitoring unit .

The standby power supply automatic input device automatically judges the fault situation according to the electrical quantity and switch quantity information provided by the integrated device of the merging unit intelligent terminal, and executes the logic corresponding to the fault type according to the fault type to ensure the reliability and stability of the power supply system.

The intelligent terminal integrated device of the merging unit sends out an optical signal according to the analog sampling value collected by the collector, the switch position of the circuit breaker and the synchronization signal of the substation, and at the same time accepts the control command from the automatic input device of the standby power supply to operate the circuit breaker mechanism.

The direction monitoring unit that monitors the direction and magnitude of the line current in real time, judges the direction and magnitude of the current according to the received bus voltage and line current.

The fault judgment and location monitoring unit judges the fault according to the monitoring results of the direction monitoring unit that monitors the direction and magnitude of the line current in real time, and locates the fault point by switching the switch.

The operation information of the device can be monitored on other clients, and corresponding data records can be stored after each action for subsequent investigation.

The invention adopts the detection unit in the substation control system that can detect the busbar voltage and incoming current direction of the station in real time, monitors the electrical quantity of the system, the circuit breaker switch information and the action signals of other protection devices in real time, and transmits it to the backup device in real time as an optical signal. The structure of the merging unit intelligent terminal integrated unit that simultaneously accepts the self-switching command from the standby and self-switching device enables the standby self-switching device system of the present invention to effectively improve the power supply reliability of the power network and the stability of the power grid operation. It can be used for self-switching of conventional backup, and can also be used as a self-switching backup with fault identification function.

Claims (8)

1. a method for identifying faults of a backup power supply automatic input device, characterized in that, comprising the following steps: A. The integrated device of merging unit intelligent terminal is centrally installed on the bus tie and incoming line to collect the busbar voltage, incoming line voltage, incoming line current, segment current and the position of incoming line and segment switch, and report the message by optical signal Send to the standby self-switching device, and simultaneously receive and execute the tripping and closing commands from the standby self-switching device to control the operation of the circuit breaker; B. The standby self-switching device automatically judges the current direction according to the relationship between the bus voltage and the incoming line current from the intelligent terminal integrated device of the line merging unit, as the criterion for fault location; The relationship between the busbar voltage and the incoming line current stipulates that the flow from the line to the busbar is the positive direction, and the directional element adopts a 90° connection. The forward direction action equation is:

where:

and

Represent the corresponding incoming current and bus voltage in the 90° connection mode; When the device judges the positive direction and the current value is greater than the fault current threshold, it means that the fault point is below the current transformer of the circuit breaker; if it is the opposite direction, it is a line fault; C. When the busbar voltage does not meet the voltage condition, and at the same time meets the backup automatic switching start conditions, the backup automatic switching device judges whether there is a busbar fault or transformer fault according to the relationship between the relevant AC quantity and electrical quantity, and then executes different strategies according to different strategies. Equipped with automatic switching logic to automatically identify fault types. 2 . The method for identifying faults of an automatic power-on device for backup power according to claim 1 , wherein the device judges in real time. 3 . 3. The method for identifying faults of an automatic switching-in device of a backup power supply according to claim 1, characterized in that: when in the self-switching mode of the bus tie backup, charging is carried out when the following conditions are all met: 1a, the bus tie switch is in an open state; 1b , the incoming line switch is in the closed state; 1c, the busbar voltage is higher than the busbar voltage setting value; Discharge when any one of the following conditions is met: 2a, the self-switching input of the locked incoming line is set to 1; 2b, the switch of one of the incoming lines is manually jumped by remote control or on-site; 2c, the transformer action signal is set to 1; 2d, the bus tie switch Closed; 2e, the voltage of the two sections of the bus does not meet the voltage time greater than 15s; 2f, the maintenance status of the intelligent terminal integrated device of the incoming line merging unit is inconsistent with the maintenance status of the standby self-switching device; 2g, the integrated device of the intelligent terminal of the bus-joint merging unit The maintenance status is inconsistent with the maintenance status of the standby automatic switching device; 2h, the bus tie standby automatic switching soft pressure plate or the control word is not put in; 2i, the incoming line switch refuses to trip or the bus tie switch refuses to close; When the standby automatic switching device receives the action signal from the transformer protection device, it is considered that there is a fault in the corresponding transformer protection at this time, and the standby automatic switching device should discharge directly; If the current flowing through the incoming line is greater than the set fault current threshold, and judged to be in the positive direction according to the direction criterion, the device determines that the corresponding bus is faulty; first cut off the incoming line switch, and close the bus tie switch; after closing the bus tie switch , if the corresponding bus fault is a transient fault, the fault has been eliminated at this time, and the system can operate normally; if the corresponding bus fault is a permanent fault, after closing the bus tie switch, the fault current through the bus tie CT is greater than the post-acceleration fixed value , at this time, start the post-acceleration function of the bus tie, cut off the bus tie switch, and isolate the fault point; If the current flowing through the incoming line is less than the set fault current threshold, or judged to be the opposite direction according to the direction criterion, the device judges that the line is faulty, first cut off the corresponding incoming line switch, and close the bus tie switch to ensure that the entire station does not lose voltage. 4. The method for identifying faults of a backup power supply automatic input device according to claim 1, characterized in that: when being in the incoming line backup self-injection mode, charging when the following conditions are all satisfied: 3a, the incoming line switch is in an off state; 3b. The other incoming line switch is in the closing state; 3c. The busbar voltage is higher than the busbar voltage setting value; 3d. The bus tie switch is in the closing state; 3e. When the incoming line voltage control word is checked, the incoming line The extraction voltage is higher than the incoming line voltage setting value; Discharge when any of the following conditions are met: 4a, the incoming line is locked and set to 1; 4b, the other incoming line switch is manually opened by remote control or on-site; 4c, the action signal of the transformer is set to 1; 4d, the incoming line The switch is closed; 4e. When checking that the incoming line voltage control word is turned on, the incoming line extraction voltage does not meet the voltage time greater than 15s; 4f. The incoming line merging unit intelligent terminal integrated device maintenance status and the standby self-switching device maintenance status Inconsistent; 4g, the maintenance status of the intelligent terminal integrated device of the bus-unit merging unit is inconsistent with the maintenance status of the standby self-throwing device; 4h, the incoming line standby self-throwing soft pressure plate or control word is not put in; 4i, another incoming line switch refuses to trip or The incoming switch refuses to close or the bus tie switch refuses to trip; When the standby automatic switching device receives the action signal from the 1# transformer protection device, it is considered that there is a fault in the 1# transformer protection at this time, and the standby automatic switching device starts at this time, jumps off the incoming line "1" switch and the bus tie switch, and then Close the incoming line "2" switch; When the standby automatic switching device receives the action signal from the 2# transformer protection device, it is considered that the 2# transformer protection is faulty at this time, and the standby automatic switching device should discharge directly to prevent the switch from closing in the fault and affect the system stability; If the current flowing through the incoming line "1" is greater than the set fault current threshold, and judged as positive direction according to the direction criterion, the device judges that the busbar is faulty, first cut off the bus tie switch, and after the bus tie switch is cut off, it flows through the incoming line "1" ” disappears, indicating that the fault point is on the II bus and has been removed; if the current flowing through the incoming line “1” still exists, it means that the fault point is on the I bus, and the device cuts off the incoming line “1” switch and closes the The upper incoming line "2" switch ensures that the II bus load is not cut off; If the current flowing through the incoming line "1" is less than the set fault current threshold, or the direction criterion is judged to be in the opposite direction, the device judges that the line is faulty, first cut off the incoming line "1" switch, close the incoming line "2" switch, Ensure that the entire station does not lose voltage. 5. The method for identifying faults of an automatic power-on device for backup power according to claim 3 or 4, wherein the backup power-on mode is self-adaptive, and the device judges by itself depending on the position of the corresponding circuit breaker, without manual switching. 6 . The method for identifying faults of an automatic power-on device for backup power according to claim 1 , wherein the optical signal is sent out in IEC61850 format. 7 . 7. A fault identification system for automatic input device of backup power supply, characterized in that: it includes automatic input device of backup power supply, integrated device of intelligent terminal of merging unit, direction monitoring unit for real-time monitoring of line current direction and magnitude, fault judgment and positioning monitoring unit , The backup power supply automatic input device automatically judges the fault condition according to the electrical quantity and switch quantity information provided by the intelligent terminal integrated device of the merging unit, and executes the logic corresponding to the fault type according to the fault type to ensure the reliability and stability of the power supply system; The intelligent terminal integrated device of the merging unit sends out an optical signal according to the analog sampling value collected by the collector, the switch position of the circuit breaker and the synchronization signal of the substation, and at the same time accepts the control command from the automatic input device of the standby power supply to operate the circuit breaker mechanism; A direction monitoring unit that monitors the direction and magnitude of the line current in real time, and judges the direction and magnitude of the current according to the received bus voltage and line current; The fault judgment and location monitoring unit judges the fault according to the monitoring results of the direction monitoring unit that monitors the direction and magnitude of the line current in real time, and locates the fault point by switching the switch. 8 . The fault identification system of an automatic power-on device for backup power according to claim 7 , wherein the operation information of the device is monitored at other clients, and corresponding data records are stored after each action for subsequent investigation. 9 .

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