CN212137272U - Locking system of intelligent substation to prevent misoperation of bus differential protection caused by wrong order of protection pressure plate - Google Patents

Abstract

The invention discloses a latching system of an intelligent substation for preventing the misoperation of bus differential protection caused by the wrong order of protection pressure plates, comprising a voltage transformer, a voltage merging unit, a current transformer, an interval intelligent terminal and a bus differential protection module; The protection module realizes the bus differential protection action through the logic operation of the complex pressure element, the differential element and the interval GOOSE outlet pressure plate. The operation steps of the locking system are: closing the voltage SV receiving pressure plate; closing the interval current SV receiving pressure plate; closing the busbar differential protection function pressure plate, and judging whether the differential element operates and whether the recompression element operates; If the element does not act and the recompression element does not act, close the GOOSE outlet pressure plate of each interval; after each pressure plate is closed and put into operation, the busbar differential protection device starts to work. The use of this locking system can reduce the probability of the operator's pressing plate operation sequence error, thereby reducing the power grid blackout accident caused by human beings, and maintaining the safe and stable operation of the power grid.

Description

The intelligent substation prevents the misoperation of the bus differential protection caused by the wrong order of the protection pressure plate locking system

technical field

The invention relates to a backstage soft pressure plate control technology of an intelligent substation, in particular to a locking system for an intelligent substation to prevent faulty operation of the bus differential protection caused by the wrong order in which the protection pressure plates are put in.

Background technique

In the intelligent substation, the protection device pressure plate adopts the soft pressure plate that can be controlled in the background machine, and the operators operate the switch in and out of the pressure plate in the background machine. Due to the incorrect order of pressure plate switching, it may cause the protection device to malfunction, especially when judging multiple sets of currents. differential protection. It has happened in the power system that the bus differential protection malfunctioned and tripped the running line when the bus differential protection was put into the pressure plate, causing accidents and affecting the safe power consumption of users. Therefore, it is urgent to prevent the intelligent substation. A latching system in which faults cause faulty bus differential protection.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention provides an intelligent substation locking system capable of preventing malfunction of bus differential protection.

In order to achieve the above purpose, the present invention provides a latching system for an intelligent substation to prevent the misoperation of the bus differential protection caused by the wrong order of the protection pressure plate, including: a voltage transformer, the voltage transformer is used to collect the analog voltage on the bus side and connect all the The analog voltage quantity is transmitted to the voltage merging unit, one end of the voltage transformer is connected to the voltage merging unit through a cable, and the other end of the voltage transformer is connected to the bus bar; the voltage merging unit, the voltage merging unit collects the analog voltage quantity And through the A/D conversion module, it is converted into a digital voltage and output to the bus differential protection module, and the voltage combining unit is connected to the bus differential protection module through an optical cable and a voltage SV receiving pressure plate; a current transformer, the current transformer is used for Collecting the analog current on the bus side and transmitting the analog current to the bay merging unit, one end of the current transformer is connected to the bay merging unit through a cable, and the other end of the current transformer is connected to the bus through the bay switch; Interval merging unit, the interval merging unit collects the analog current and converts it into digital current through the A/D conversion module and outputs it to the bus difference protection module, the interval merging unit receives the pressure plate and the bus difference through the optical cable and the interval current SV. The protection module is connected; the interval intelligent terminal, one end of the interval intelligent terminal is connected with the interval switch through the cable and the interval trip outlet pressure plate, and the other end of the interval intelligent terminal is connected with the interval GOOSE outlet pressure plate of the bus differential protection module through the optical cable, so The said interval intelligent terminal controls the on-off of the interval switch according to the command received by the interval GOOSE outlet pressure plate.

In a preferred manner, the bus differential protection module includes a recompression element, a differential element and a spaced GOOSE outlet pressure plate; wherein, the voltage combining unit is connected to the recompression element of the bus differential protection module through an optical cable and a voltage SV receiving pressure plate ; The digital voltage received by the complex pressure element is filtered into positive, negative and zero-sequence voltage components after being filtered by the sequence component, and a logical OR gate operation is performed: when the positive, negative and zero-sequence voltage components meet the OR gate conditions, the complex pressure Component action; when the positive, negative and zero-sequence voltage components do not meet the OR gate conditions, the complex pressure element does not act.

In a preferred manner, the interval merging unit is connected to the differential element of the bus differential protection module through an optical cable and an interval current SV receiving pressure plate; the digital current received by the differential element undergoes logical operations: when the digital current is received When the current setting value of the differential element is greater than that of the differential element, the differential element acts; when the digital current is less than the current setting value of the differential element, the differential element does not act; The busbar differential protection function pressure plate performs the logical AND gate operation of the interval GOOSE outlet pressure plate: when the AND gate condition is satisfied, the interval GOOSE outlet pressure plate sends a trip command to the interval intelligent terminal; when the AND gate condition is not satisfied, the interval GOOSE outlet The pressure plate does not issue a trip command to the bay smart terminal.

The beneficial effects of the present invention are as follows: the use of the locking system can reduce the error probability of operating personnel pressing the plate operation sequence, thereby reducing the power grid blackout accident caused by human beings, and maintaining the safe and stable operation of the power grid.

Description of drawings

Figure 1 is a schematic diagram of the intelligent substation bus differential protection pressure plate;

Fig. 2 is the logic diagram of the input sequence of the busbar differential protection pressure plate of the intelligent substation;

Fig. 3 is the working principle diagram of the bus differential protection complex pressure element of the intelligent substation;

Fig. 4 is the working principle diagram of the differential element of the bus differential protection of the intelligent substation;

Figure 5 is the working principle diagram of the GOOSE outlet pressure plate of the bus differential protection interval of the intelligent substation.

Detailed ways

Figure 1 shows the principle diagram of the bus differential protection pressure plate of the intelligent substation, in which 1, 2, and 3 are respectively the #1 line, #2 line, and #3 line interval trip outlet pressure plate, the interval trip outlet pressure plate is a hard pressure plate, 4 Voltage SV receiving pressure plate, 5, 6, 7 respectively #1 line, #2 line, #3 line interval current SV receiving pressure plate, 8, 9, 10 respectively #1 line, #2 line, #3 line interval GOOSE The outlet pressure plate, 11 is the busbar differential protection function pressure plate; the above pressure plates except the hard pressure plate are all soft pressure plates that can be operated in the background machine, and each bay is in operation, and the outlet pressure plate of each bay trip must be put in. In addition, it also includes busbars, voltage transformers, current transformers and circuit breakers; their functions are as follows: In the power system, the busbar connects the various current-carrying branch circuits in the power distribution device, and plays the role of collecting, distributing and transmitting electrical energy. The role of the voltage transformer is to convert the high voltage into a standard secondary voltage of 100V or lower in a proportional relationship, which is used for protection, metering and instrumentation devices. At the same time, the use of voltage transformers can isolate high voltages from electrical workers; current transformers act like voltage transformers, except that they convert the amount of current; circuit breakers are #1, #2, #3 interval switches, which are used in power When the system is in normal operation, it is used to close and disconnect the circuit. In the event of a fault, the faulty equipment is automatically disconnected from the line under the control of the electromechanical protection device, and it can also have an automatic reclosing function.

As shown in Figure 3, the working principle of the compound voltage element: the voltage transformer is used to collect the analog voltage on the bus side and transmit the analog voltage to the voltage merging unit, and the voltage transformer is connected to the voltage merging unit through a cable The voltage merging unit collects the analog voltage quantity and converts it into a digital voltage quantity through the A/D conversion module and outputs it to the bus differential protection module, and the voltage merging unit receives the complex connection between the pressure plate and the bus differential protection module through the optical cable and the voltage SV. The digital voltage received by the complex pressure element is filtered by the sequence component and divided into positive, negative and zero-sequence voltage components and performs logical OR gate operation: when the positive, negative and zero-sequence voltage components meet the OR gate conditions , the complex pressure element acts; when the positive, negative and zero sequence voltage components do not meet the OR gate conditions, the complex pressure element does not act.

As shown in FIG. 4 , the current transformer is used to collect the analog current on the bus side and transmit the analog current to the bay combining unit; the bay combining unit collects the analog current and converts the analog current through the A/D conversion module into The digital current is output to the bus differential protection module, and the interval merging unit is connected to the differential element of the bus differential protection module through an optical cable and an interval current SV receiving pressure plate; the digital current received by the differential element undergoes logical operations: When the digital current amount is greater than the current setting value of the differential element, the differential element operates; when the digital current amount is smaller than the current setting value of the differential element, the differential element does not operate.

As shown in Figure 5, one end of the interval intelligent terminal is connected to the interval switch through a cable and the interval trip outlet pressure plate, and the other end of the interval intelligent terminal is connected to the interval GOOSE outlet pressure plate through an optical cable, and the interval intelligent terminal is used to control the interval On-off of the switch; the differential element, re-pressure element and bus differential protection function pressure plate of the bus differential protection module perform the logical AND gate operation of the interval GOOSE outlet pressure plate. When the AND gate conditions are met, the interval GOOSE outlet pressure plate is sent to The said bay intelligent terminal issues a trip command; when the AND gate conditions are not met, the bay GOOSE outlet pressure plate does not issue a trip command to the bay smart terminal. When the differential protection function pressure plate is turned on, the differential element is activated, and the complex pressure blocking element is opened at the same time, the bus differential protection module satisfies the action, and the switch trip command is sent to each bay through the control of the GOOSE outlet pressure plate of each bay; the bay intelligent terminal Receive the digital GOOSE trip command, convert the digital quantity into electrical quantity through D/A conversion, and then drive the relay to act. The trip coil of the switch energizes and trips the bay switch.

In the power system, there has been an accident of malfunction caused by the wrong sequence of inputting the pressure plate. The accident happened: the operating personnel put the bus differential protection into work, and the pressure plate input sequence is as follows: close the busbar differential protection function pressure plate, close each interval GOOSE The outlet pressure plate and input #1 line interval current SV receiving pressure plate, at this time, the busbar differential protection action trips each line switch, resulting in a power outage accident for all lines.

Analysis of the cause of the accident: The action principle of the bus differential protection is that when the bus differential protection is put into the pressing plate, the operating current of each interval is received by the receiving pressure plate of each interval current SV, and the current amount of each interval is calculated according to "Kirchhoff's current law". The vector sum is called differential current. During normal operation, the differential current is close to 0A, which is less than the bus differential protection setting, and the differential element will not act. At the same time, the bus voltage received by the voltage SV receiving platen is normal, and the recompression element will not act. Therefore, The busbar differential protection will not operate the outlet. When the busbar fails, the differential current is greater than the fixed value of the busbar differential protection, the differential element acts, and at the same time the busbar voltage decreases, the recompression element acts, the busbar differential protection issues a trip command, and the trip command is sent to the GOOSE outlet pressure plate of each bay and the tripping outlet pressure plate of each bay. Each line switch issues a trip command.

Reasons for malfunction: The operator first closes the busbar differential protection function pressure plate, closes the GOOSE outlet pressure plate of each bay, and closes the #1 line interval current SV receiving pressure plate. At this time, the busbar differential protection only receives part of the interval current, so the calculation The sum of the output current vector is greater than the fixed value of the bus differential protection, and the differential element operates; and because there is no input voltage SV receiving pressure plate, the bus differential protection has no voltage and causes the bus differential protection voltage to open, which is equivalent to the action of the complex pressure element. Therefore, the busbar differential protection sends a trip command to each line switch through the GOOSE outlet pressure plate of each bay and the tripping outlet pressure plate of each bay, causing an accident.

According to the above analysis of the cause of the accident, it is concluded that the bus differential protection is put into operation, and the correct operation sequence is:

S1: In the busbar differential protection device, first close the voltage SV receiving pressure plate;

S2: close the #1 line interval current SV receiving pressure plate, #2 line interval current SV receiving pressure plate, #3 line interval current SV receiving pressure plate;

S3: Close the busbar differential protection function pressure plate, and judge whether the differential element operates and whether the recompression element operates;

S4: If the differential element does not act and the recompression element does not act, then close the #1 line interval GOOSE outlet pressure plate, #2 line interval GOOSE outlet pressure plate, #3 line interval GOOSE outlet pressure plate;

S5: After the pressure plates are all closed and put into operation, the busbar differential protection device starts to work.

As shown in Figure 2, the busbar differential protection function pressure plate has been closed, the voltage SV receiving pressure plate has been closed, the current SV receiving pressure plate of each interval has been closed, the differential element does not operate, and the complex pressure element does not operate conditions are output through the AND gate And close the GOOSE outlet command of each bay and then output it through the AND gate, so that the GOOSE outlet pressure plate of each bay can be put into operation. This logic requires that the busbar differential protection function pressure plate has been closed, the voltage SV receiving pressure plate has been closed, the current SV receiving pressure plate of each interval has been closed, the differential element has not acted, and the complex pressure element has not acted. The reason why the outlet pressure plate is put in is that only when the busbar differential protection function pressure plate is closed can it be judged whether the differential element operates; only when the voltage SV receiving pressure plate is closed can it be judged whether the compound pressure element is in operation; only when each interval current SV receiving pressure plate is closed, The differential current can be calculated correctly only by the bus differential protection, and it can prevent the misoperation caused by inputting each interval current SV receiving pressure plate after the bus differential tripping outlet is switched on. It will not malfunction to prevent the switch from tripping due to the input and outlet pressure plate.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (3)

1. The utility model provides an intelligent substation prevents that protection clamp plate from putting into the locking system that sequence error caused busbar differential protection malfunction which characterized in that includes: the voltage transformer is used for collecting analog voltage quantity at the bus side and transmitting the analog voltage quantity to the voltage merging unit, one end of the voltage transformer is connected with the voltage merging unit through a cable, and the other end of the voltage transformer is connected with the bus; the voltage merging unit collects analog voltage quantity, converts the analog voltage quantity into digital voltage quantity through the A/D conversion module and outputs the digital voltage quantity to the bus differential protection module, and is connected with the bus differential protection module through an optical cable and a voltage SV receiving pressing plate; the current transformer is used for collecting the analog current amount at the bus side and transmitting the analog current amount to the interval merging unit, one end of the current transformer is connected with the interval merging unit through a cable, and the other end of the current transformer is connected with the bus through an interval switch; the interval merging unit collects analog current quantity, converts the analog current quantity into digital current quantity through an A/D conversion module and outputs the digital current quantity to the bus differential protection module, and is connected with the bus differential protection module through an optical cable and an interval current SV receiving pressing plate; the interval intelligent terminal is connected with the interval switch through a cable and an interval tripping outlet pressing plate, the other end of the interval intelligent terminal is connected with the interval GOOSE outlet pressing plate of the bus differential protection module through an optical cable, and the interval intelligent terminal controls the on-off of the interval switch according to a received command of the interval GOOSE outlet pressing plate.

2. The intelligent substation of claim 1, wherein the busbar differential protection module comprises a composite pressure element, a differential element and a spacing GOOSE outlet pressure plate; the voltage merging unit is connected with a composite pressure element of the bus differential protection module through an optical cable and a voltage SV receiving pressure plate.

3. The intelligent substation locking system for preventing busbar differential protection misoperation caused by wrong switching sequence of protection pressing plates according to claim 1 or 2 is characterized in that the interval merging unit is connected with a differential element of the busbar differential protection module through an optical cable and an interval current SV receiving pressing plate.

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