CN209329687U - A kind of traction substation emergency protection system - Google Patents

Abstract

The utility model provides an emergency protection system for a traction substation. The system is applicable to the situation that the opening coils of the existing main transformer high-voltage side circuit breakers in the traction substation are all occupied. The system includes: an emergency protection device, which controls the action of the emergency protection circuit according to the emergency protection signal; The protection circuit, under the control of the emergency protection device, disconnects the existing circuit of the opening coil, and forms a new protection circuit with the opening coil. The utility model is suitable for the situation that only one or two opening coils of the high-voltage side circuit breaker of the main transformer in the existing traction substation are occupied, and can make the traction substation control and protection system work abnormally. The power substation can quickly withdraw from operation to avoid greater secondary accidents, and can ensure that the emergency protection power supply and the existing circuit will not be cross-wired, keep the electrical circuit independent, and can upgrade and transform the existing traction transformer without affecting the existing protection. electric station.

Description

An emergency protection system for traction substation

technical field

The utility model relates to the technical field of traction substation protection, in particular to an emergency protection system for traction substations.

Background technique

Traction substation is an important facility of electrified railway, responsible for transforming the electric energy of the power system into electric energy suitable for electric traction, and supplying power to electric locomotives through catenary. The failure of the traction substation will cause the catenary to lose power and affect the railway transportation.

The control and protection system of the traction substation is composed of independent protection devices such as traction transformer protection and feeder protection. The operating power of the protection devices and switchgear is supplied by the DC power supply in the traction substation.

The control and protection system is an important device in the traction substation, and it is a weak current device without backup. When the traction substation suffers from lightning strike, high voltage switch insulation breakdown, earthquake, fire, DC power failure, etc., it may affect the normal operation of the control and protection system in the substation.

When the control and protection system fails to work normally, the primary equipment of the traction substation will be in a state of no relay protection. If the traction substation continues to operate, there will be a high safety risk, because once In the event of short circuit, overload and other faults, the circuit breakers at all levels will not be able to trip, which will endanger the safety of people, equipment and system operation, and in severe cases will cause major accidents such as equipment fires. Therefore, enough attention should be paid to the serious consequences caused by the abnormal operation of the control and protection system in the institute, and an emergency remedy method should be studied.

Utility model content

The purpose of the embodiment of the utility model is to provide an emergency protection system for a traction substation to solve the problem of no relay protection in the traction substation caused by the abnormal operation of the control and protection system of the traction substation.

The embodiment of the utility model provides an emergency protection system for a traction substation, which is characterized in that the system is suitable for the case where all the opening coils of the high-voltage side circuit breakers of the main transformer in the traction substation are occupied. The system includes:

The emergency protection device controls the action of the emergency protection circuit according to the emergency protection signal;

The emergency protection circuit, under the control of the emergency protection device, disconnects the existing circuit of the opening coil, and forms a new protection circuit with the opening coil.

Further, the system also includes:

The power supply provides DC power for the emergency protection device and the emergency protection circuit.

Further, the power supply also includes:

The storage battery provides DC power for the emergency protection device and the emergency protection circuit after the power supply loses power.

Further, the emergency protection circuit includes:

The relay control circuit controls the action of the relay under the control of the emergency protection device;

The time-delay relay control circuit controls the action of the time-delay relay under the control of the emergency protection device;

Existing opening disconnect circuit, disconnecting the existing circuit of the opening coil;

The emergency protection opening circuit forms a new protection circuit with the opening coil.

Further, the relay control circuit includes a first relay coil, a second relay coil, and a normally open contact of a power isolation control relay. After the coils of the first relay coil and the second relay are connected in parallel, they are connected to the power isolation control Between one end of the normally open contact of the relay and the negative pole of the power supply;

The delay relay control circuit includes a trip relay normally open contact and a delay relay coil, the normally open contact of the trip relay and the delay relay are connected in series between the positive pole and the negative pole of the power supply;

The existing opening and disconnecting circuit includes the normally closed contacts of the first relay and the second relay, and the normally closed contacts of the first relay and the second relay are connected in series to the existing opening coil of the opening coil after being connected in parallel. in the circuit;

The emergency protection opening circuit includes the first normally open contact and the second normally open contact of the first relay, the second relay and the delay relay, and the first contact of the first relay, the second relay and the delay relay The normally open contacts are connected in series between the positive pole of the power supply and one end of the opening coil; the second normally open contacts of the first relay, the second relay, and the delay relay are connected in series at the other end of the opening coil and the negative terminal of the power supply.

Further, the delay time of the delay relay is set according to the safe disconnection time of the opening coil.

Further, the emergency protection device includes:

The signal acquisition unit collects various signals required for tripping;

A controller, receiving the signal transmitted by the signal acquisition unit, and outputting a control signal to control the action of the power isolation control relay and the delay relay when the signal or a combination of various signals meets the protection trip condition .

Further, the signal acquisition unit includes:

The voltage relay is arranged on each section of the DC power bus of the protection panel of the traction substation, and collects the power-off signal and sends it to the controller;

The current sensor collects the main transformer current signal and sends it to the controller.

Further, the voltage relay corresponds to at least one redundant voltage relay, and the two voltage relays work at the same time, and the contacts are connected in series to the controller electrically, and the power-off signal is collected and sent to the controller.

Further, the signal acquisition unit also includes:

In the earthquake monitoring system, two sets of independent passive normally open contacts are connected in parallel and then electrically connected to the controller, and the monitoring earthquake signal is sent to the controller;

The fire detector is electrically connected with the controller, and the fire monitoring signal is sent to the controller.

The technical solution provided by the embodiment of the utility model is suitable for the situation that only one or two of the opening coils of the high-voltage side circuit breaker of the main transformer in the existing traction substation are occupied, and can be controlled in the traction substation When the protection system does not work normally, the traction substation can be quickly withdrawn from operation to avoid causing greater secondary accidents, and it can ensure that the emergency protection power supply and the existing circuit will not be cross-wired, keeping the electrical circuit independent, and can be used without affecting the existing protection. In the case of upgrading and transforming existing traction substations, it greatly improves the reliability of railway power consumption, reduces the impact of accidents on the operation of railway traction substations, and reduces the economic cost and cost of upgrading and transforming existing traction substations. Time cost, guarantee the safety of equipment operation and personnel safety, and avoid the expansion of accidents.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some implementations of the present invention. For example, those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.

Figure 1 is a schematic diagram of the composition of an emergency protection circuit for a traction substation provided by an embodiment of the utility model;

Fig. 2 is a schematic diagram of the composition of an emergency protection device for a traction substation provided by an embodiment of the utility model;

Fig. 3 is a schematic diagram of the principle of a power supply provided by an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the specific implementation of the technical solutions of the utility model will be described in more detail and clearly below in conjunction with the drawings and embodiments. However, the specific embodiments and examples described below are only for the purpose of illustration, rather than limiting the present utility model. It only includes a part of the embodiments of the utility model, but not all the embodiments. Other embodiments obtained by those skilled in the art for various changes of the utility model all belong to the scope of protection of the utility model.

It should be understood that although the terms first, second, third, etc. may be used herein to describe various elements or components, these elements or components should not be limited by these terms. These terms are only used to distinguish one element or component from another element or component. Therefore, a first element or component discussed below may be referred to as a second element or a second component without departing from the scope of the present invention.

An emergency protection system for a traction substation is applicable to the situation that all the opening coils of the existing main transformer high-voltage side circuit breakers in the traction substation are occupied. The system includes an emergency protection device and an emergency protection circuit.

The emergency protection device controls the action of the emergency protection circuit according to the emergency protection signal. Under the control of the emergency protection device, the emergency protection circuit disconnects the existing circuit of the opening coil and forms a new protection circuit with the opening coil.

The system also includes a power supply to provide DC power for the emergency protection device and the emergency protection circuit. This power supply is independent of the existing DC power supply system in the traction substation.

Figure 1 is a schematic diagram of the composition of an emergency protection circuit for a traction substation provided by an embodiment of the utility model. The emergency protection circuit includes a relay control circuit, a delay relay control circuit, an existing opening and closing circuit, and an emergency protection opening circuit .

As shown in Figure 1, during normal operation, the negative terminal of the opening coil TQ of the high-voltage circuit breaker of the main transformer is connected to the original control power supply -KM through the normally closed contact 1ZJ4 or 2ZJ4 of the intermediate relay, and the positive terminal is connected to the original control power supply through the normally closed contact 1ZJ2 or 2ZJ2. The protection opening circuit is connected, the emergency protection device +KM' is isolated and segmented by the 1ZJ1, 2ZJ1, 3ZJ1 contacts, and the emergency protection -KM' is isolated and segmented by the 1ZJ3, 2ZJ3, 2ZJ3 contacts.

When the emergency protection signal appears, the relay control circuit controls the action of the relay under the control of the emergency protection device. The delay relay control circuit controls the action of the delay relay under the control of the emergency protection device. The existing opening disconnect circuit breaks the existing circuit of the opening coil. The emergency protection opening circuit and the opening coil form a new protection circuit.

The relay control circuit includes a first relay coil 1ZJ, a second relay coil 2ZJ, and a normally open contact 1KJ1 of a power isolation control relay. After the first relay coil 1ZJ and the second relay coil 2ZJ are connected in parallel, they are connected between one end of the normally open contact 1KJ1 of the power isolation control relay and the negative pole -KM' of the power supply.

The delay relay control circuit includes a trip relay normally open contact 1TJ1 and a delay relay coil 3ZJ. The normally open contact 1TJ1 of the trip relay and the delay relay coil 3ZJ are connected in series between the positive pole +KM' and the negative pole -KM' of the power supply.

The existing opening and breaking circuit includes a first relay normally closed contact 1ZJ2 and a second relay normally closed contact 2ZJ2. The first relay normally closed contact 1ZJ2 and the second relay normally closed contact 2ZJ2 are connected in parallel and then connected in series in the existing circuit of the opening coil TQ.

The emergency protection opening circuit includes the first normally open contact 1ZJ1 of the first relay, the second normally open contact 1ZJ3 of the first relay, the first normally open contact 2ZJ1 of the second relay, the second normally open contact 2ZJ3 of the second relay, and the second normally open contact 2ZJ3 of the delay relay. One normally open contact 3ZJ1, the second normally open contact 3ZJ3 of the delay relay. The first normally open contact 1ZJ1 of the first relay, the first normally open contact 2ZJ1 of the second relay, and the first normally open contact 3ZJ1 of the delay relay are connected in series to the positive pole +KM' of the power supply and one end of the opening coil TQ. The second normally open contact 1ZJ3 of the first relay, the second normally open contact 2ZJ3 of the second relay, and the second normally open contact 3ZJ3 of the delay relay are connected in series between the other end of the opening coil and the negative pole -KM' of the power supply.

The delay time of the delay relay 3ZJ is set according to the safe disconnection time of the opening coil TQ.

When the emergency protection device operates, the emergency protection device first controls the power isolation control relay 1KJ to act, and the power isolation control relay normally open contact 1KJ1 closes, driving the first relay coil 1ZJ and the second relay coil 2ZJ to receive power, so that 1ZJ2, 1ZJ4, 2ZJ2, 2ZJ4 contacts open, 1ZJ1, 1ZJ3, 2ZJ1, 2ZJ3 close, to ensure that the circuit breaker opening coil TQ is disconnected from the original protection opening circuit.

Then the emergency protection device controls the tripping relay coil 1TJ to act after a delay, and drives the delay relay coil 3ZJ to receive power, so that the contacts 3ZJ1 and 3ZJ3 are closed. At this time, the opening coil of the circuit breaker is switched to the opening circuit of the emergency protection device to drive the opening The coil is tripped.

For the circuit breaker with only one opening coil in the existing traction substation, or the circuit breaker with both opening coils occupied, the electrical isolation between the emergency protection and the original protection circuit is realized through this circuit design, and the transformation is basically avoided The original protection circuit greatly improves the safety and reliability of the upgrade of the existing traction substation.

FIG. 2 is a schematic diagram of the composition of an emergency protection device for a traction substation provided by an embodiment of the utility model. The emergency protection device includes a signal acquisition unit and a controller 21 .

The signal acquisition unit collects various signals required for tripping. The controller 21 receives the signal transmitted by the signal acquisition unit, and when the signal or a combination of various signals meets the protection and tripping conditions, it outputs a control signal to control the action of the power isolation control relay 1KJ and the tripping relay 1TJ.

The signal acquisition unit includes a voltage relay YJ and a current sensor TA.

The voltage relay YJ is set on each segment of the DC power bus of the protection panel of the traction substation, and collects the power-off signal and sends it to the controller 21 . The power-off signal is that the DC bus of the main transformer protection panel and the DC bus of the feeder protection panel in the power system of the existing traction substation meet the power-off conditions at the same time. The current sensor TA collects the main transformer current signal and sends it to the controller 21 .

Preferably, in order to avoid misjudgment caused by a single relay failure, the voltage relay YJ corresponds to at least one redundant voltage relay, and the two voltage relays work simultaneously to monitor the bus voltage. After the contacts are connected in series, they are electrically connected to the controller 21, and the power-off signal is collected and sent to controller 21. In the case of group ring supply, the main transformer protection panel and the feeder protection panel are respectively equipped with power busbars, and the emergency protection device will start to protect and trip only after the emergency protection device receives the power-off signal of the main transformer protection panel and the feeder protection panel at the same time .

As an optional solution, the signal acquisition unit may also include an earthquake monitoring system 22 and a fire detector 23 .

Two sets of independent passive normally open contacts of the earthquake monitoring system 22 are connected in parallel and electrically connected to the controller 21 , and the monitoring earthquake signal is sent to the controller 21 . The fire detector 23 is electrically connected to the controller 21 , and the fire monitoring signal is sent to the controller 21 .

The emergency protection device conducts comprehensive analysis and judgment on the collected signal input to determine the action conditions of the emergency protection device. Among them, the power failure signal in the traction substation is used as the main criterion for the protection trip of the emergency protection device, the voltage and current signals are used as the auxiliary criterion, and the earthquake signal and fire signal are used as optional signals.

The power failure signal can be applied to the situation of power failure maintenance in traction substations. When the DC bus power supply of the existing protection system is artificially pulled down, the emergency protection device can judge by itself according to logic, and only alarm but not trip.

The protection action includes that after the signal input condition criterion is satisfied, the emergency protection device trips the circuit breaker on the high voltage side of the main transformer and cuts off the power supply of the traction substation. For a circuit breaker with only one opening coil or both opening coils occupied, after the protection trip condition is met, the emergency protection device needs to isolate the original protection opening circuit before tripping the circuit breaker to cut off the traction substation. All power.

Fig. 3 is a schematic diagram of the principle of a power supply provided by an embodiment of the present invention. As shown in FIG. 3 , the power supply includes an isolation transformer 31 , a surge protector 32 , a rectification module 33 , and a power monitoring unit 34 . The power supply is introduced into one AC power supply from the AC panel in the traction substation, and after being isolated by the isolation transformer 31 , it is converted into a DC power supply by the rectification module 33 . The surge protector 32 and the power monitoring unit 34 are used to monitor and protect the working state of the power supply.

Preferably, the power supply may also include a storage battery 35 . The storage battery 35 provides DC power for the emergency protection device and the emergency protection circuit after the power failure. The capacity of the storage battery 35 is not less than 10Ah.

It should be noted that the various embodiments described above with reference to the accompanying drawings are only used to illustrate the utility model rather than limit the scope of the utility model, those of ordinary skill in the art should understand that without departing from the spirit and scope of the utility model Any modifications or equivalent replacements made to the present utility model under the premise of the present utility model shall be covered within the scope of the present utility model. Further, words appearing in the singular include the plural and vice versa unless the context otherwise requires. Additionally, all or a portion of any embodiment may be utilized with all or a portion of any other embodiment, unless stated otherwise.

Claims (8)

1. An emergency protection system for a traction substation, characterized in that the system is applicable to the situation that the opening coils of the existing main transformer high-voltage side circuit breakers of the traction substation are all occupied, and the system includes: The emergency protection device controls the action of the emergency protection circuit according to the emergency protection signal; The emergency protection circuit, under the control of the emergency protection device, disconnects the existing circuit of the opening coil, and forms a new protection circuit with the opening coil; The emergency protection circuit includes: The relay control circuit controls the action of the relay under the control of the emergency protection device; The delay relay control circuit controls the action of the delay relay under the control of the emergency protection device, wherein the delay time of the delay relay is set according to the safe disconnection time of the opening coil; Existing opening disconnect circuit, disconnecting the existing circuit of the opening coil; The emergency protection opening circuit forms a new protection circuit with the opening coil. 2. The system according to claim 1, further comprising: The power supply provides DC power for the emergency protection device and the emergency protection circuit. 3. The system according to claim 2, wherein the power supply further comprises: The storage battery provides DC power for the emergency protection device and the emergency protection circuit after the power supply loses power. 4. The system of claim 1, wherein: The relay control circuit includes a first relay coil, a second relay coil, and a normally open contact of a power isolation control relay. After the coils of the first relay coil and the second relay are connected in parallel, they are connected to the normally open contact of the power isolation control relay. Between one end of the open contact and the negative pole of the power supply; The delay relay control circuit includes a trip relay normally open contact and a delay relay coil, the normally open contact of the trip relay and the delay relay are connected in series between the positive pole and the negative pole of the power supply; The existing opening and breaking circuit includes the normally closed contacts of the first relay and the second relay, and the normally closed contacts of the first relay and the second relay are connected in series to the existing opening coil of the opening coil after being connected in parallel. in the circuit; The emergency protection opening circuit includes the first normally open contact and the second normally open contact of the first relay, the second relay and the delay relay, and the first contact of the first relay, the second relay and the delay relay The normally open contacts are connected in series between the positive pole of the power supply and one end of the opening coil; the second normally open contacts of the first relay, the second relay, and the delay relay are connected in series at the other end of the opening coil and the negative terminal of the power supply. 5. The system according to claim 4, wherein the emergency protection device comprises: The signal acquisition unit collects various signals required for tripping; The controller receives the signal transmitted by the signal acquisition unit, and outputs a control signal to control the action of the power isolation control relay and the trip relay when the signal or a combination of various signals meets the protection tripping condition. 6. The system according to claim 5, wherein the signal acquisition unit comprises: The voltage relay is arranged on each section of the DC power bus of the protection panel of the traction substation, and collects the power-off signal and sends it to the controller; The current sensor collects the main transformer current signal and sends it to the controller. 7. The system according to claim 6, wherein the voltage relay corresponds to at least one redundant voltage relay, and the two voltage relays work at the same time, and the contacts are connected in series to the controller electrically, and the acquisition failure Electrical signals are sent to the controller. 8. The system according to claim 6 or 7, wherein the signal acquisition unit further comprises: In the earthquake monitoring system, two sets of independent passive normally open contacts are connected in parallel and then electrically connected to the controller, and the monitoring earthquake signal is sent to the controller; The fire detector is electrically connected with the controller, and the fire monitoring signal is sent to the controller.