CN207184025U - Circuit breaker emergency trip control circuit after all DC power disappears - Google Patents

Abstract

The utility model discloses an emergency trip control circuit of a circuit breaker after the direct current power supply disappears completely, which solves the problem of how to remove faulty equipment after the direct current power supply disappears. Electromagnetic voltage relays are connected between the positive and negative poles of each section of the DC power supply bus. The normally closed contacts of the electromagnetic voltage relays of each section of the DC power supply bus are connected in series to form one end of the series branch and one pole of the supercapacitor (1). connection, the other end of the series branch is connected to the parallel connection point (B), and the trip coil (8) of the high-voltage side circuit breaker, the trip coil (10) of the medium-voltage side circuit breaker and the trip coil (12) of the low-voltage side circuit breaker are connected in parallel. One end is connected to the other parallel connection point (B), and the high-voltage side circuit breaker trip coil (8), the medium-voltage side circuit breaker trip coil and the low-voltage side circuit breaker trip coil (12) are connected in parallel through the button (4) and the supercapacitor (1) to the other pole connection. It is especially suitable for on-site operators to operate and use.

Description

Circuit breaker emergency trip control circuit after all DC power disappears

technical field

The invention relates to an emergency tripping method for circuit breakers on the high-voltage side, medium-voltage side and low-voltage side when all DC power sources in a power plant or a substation disappear, and is suitable for emergency situations in a power plant or a substation It can effectively avoid the occurrence of major accidents in which the circuit breaker cannot be tripped in an emergency due to the loss of DC power supply, resulting in large-area burning of the power supply equipment.

Background technique

The DC power supply system in a power plant or substation is composed of AC charging cabinets, battery packs, DC circuit breakers, DC busbars, and fuses. It is used for control, signal, relay protection, automatic devices and Provide DC power supply for emergency lighting, etc. In addition, it also provides reliable DC power supply for equipment operation. The reliable power supply of the DC power system plays a pivotal role in the safe operation of the power plant or substation, and is a reliable guarantee for the safe operation of the substation. In recent years, there have been many accidents in the power grid due to the disappearance of the DC power supply of the entire substation, which made the protection device unable to work, and the circuit breaker tripped and closed the coil and lost the DC power supply, so the faulty line could not be cut off, which eventually led to the burning of all or part of the equipment in the entire substation. Serious accidents not only cause huge economic losses to power supply companies, but also bring huge losses to some users, and even threaten the safe operation of the entire power grid.

In power plants or substations, failure or disconnection of the DC power supply system will cause the DC power supply to disappear, which will cause the circuit breaker to fail to operate. Remove the faulty equipment within the time limit. The existing technology relies on the delay of the backup protection of the transmission line of the power plant or substation connected to it to remove the faulty equipment, or disconnect the relevant equipment under the command of the dispatcher. These measures exist The response time is long, and there are many wrong operations caused by human factors, which cannot play the role of emergency avoidance, and will also bring the disadvantage of expanding the scope of power outages. Therefore, when the DC power supply in the power plant or substation disappears, how to remove the faulty equipment without the DC power supply has become a technical problem that needs to be solved urgently in the operation of the substation.

Contents of the invention

The invention relates to a circuit breaker emergency trip control circuit and control method after all DC power sources disappear, and solves the technical problem of how to remove faulty equipment without DC power sources when DC power sources in power plants or substations disappear.

The present invention solves the above technical problems through the following technical solutions:

A circuit breaker emergency trip control circuit after the DC power supply completely disappears, including a high-voltage side circuit breaker trip coil, a high-voltage side circuit breaker first auxiliary contact, a high-voltage side circuit breaker second auxiliary contact, and a medium-voltage side circuit breaker trip coil in a substation , The first auxiliary contact of the circuit breaker on the medium voltage side, the second auxiliary contact of the circuit breaker on the medium voltage side, the tripping coil of the circuit breaker on the low voltage side, the first auxiliary contact of the circuit breaker on the low voltage side, the second auxiliary contact of the circuit breaker on the low voltage side; set in the substation There is a DC power bus, and a DC power bus electromagnetic voltage relay is connected between the positive and negative poles of the DC power bus. One end of the normally closed contact of the DC power bus electromagnetic voltage relay is connected to one pole of the supercapacitor. The DC power bus The other end of the normally closed contact of the electromagnetic voltage relay is connected with the parallel connection point. The transformer pressure release contact, the transformer heavy gas relay contact and the button are connected in parallel to form a switch parallel branch circuit. One end of the switch parallel branch circuit is connected to the other end of the supercapacitor The other end of the parallel branch of the switch is connected with another parallel connection point; one end of the trip coil of the high-voltage side circuit breaker is connected with another parallel connection point after passing through the first auxiliary contact of the high-voltage side circuit breaker. The other end of the trip coil of the high-voltage side circuit breaker is connected to the parallel connection point after passing through the second auxiliary contact of the high-voltage side circuit breaker; one end of the trip coil of the medium-voltage side circuit breaker passes through the first auxiliary contact of the The parallel connection points are connected together, and the other end of the trip coil of the medium-voltage side circuit breaker is connected with the parallel connection point after passing through the second auxiliary contact of the medium-voltage side circuit breaker; one end of the trip coil of the low-voltage side circuit breaker passes through the first An auxiliary contact is connected together with another parallel connection point, and the other end of the trip coil of the low-voltage side circuit breaker is connected together with the parallel connection point after passing through the second auxiliary contact point of the low-voltage side circuit breaker.

A high-voltage side current limiting resistor is set between another parallel connection point and the first auxiliary contact of the high-voltage side circuit breaker; a medium-voltage side current-limiting resistor is set between another parallel connection point and the first auxiliary contact of the medium-voltage side circuit breaker Resistor; a low-voltage side current-limiting resistor is set between another parallel connection point and the first auxiliary contact of the low-voltage side circuit breaker.

In the substation, there are multiple sets of DC power bus bars consisting of the first DC power bus, the second DC power bus, and the Nth DC power bus. The positive and negative poles of the first DC power bus are connected with The first section of DC power bus electromagnetic voltage relay is connected between the positive and negative poles of the second section of DC power bus, and the second section of DC power bus electromagnetic voltage relay is connected until between the positive and negative poles of the Nth section of DC power bus Connected with the Nth DC power bus electromagnetic voltage relay, the first DC power bus electromagnetic voltage relay normally closed contact, the second DC power bus electromagnetic voltage relay normally closed contact, until the Nth DC power bus electromagnetic The normally closed contacts of the voltage relay are connected in series to form a normally closed contact series branch. One end of the normally closed contact series branch is connected to one pole of the super capacitor, and the other end of the normally closed contact series branch is connected to the parallel connection.

A charging device is connected to both ends of the supercapacitor.

All of the circuit breaker trip coils and DC power bus bars mentioned above are also part of the equipment of the power plant.

A control method for emergency tripping of a circuit breaker after all DC power sources disappear, comprising the following steps:

The first step is to sort the DC power busbars in the substation. The first DC power busbar is represented by I, the second DC power busbar is represented by II, and so on, the Nth DC power busbar is represented by N;

In the second step, the voltage of the first section of the DC power supply bus is represented by U _I ; the voltage of the second section of the DC power supply bus is represented by U _II ; and so on, the Nth section of the DC power supply bus is represented by U _N ;

The third step is to install an electromagnetic DC voltage relay on each DC power bus. The electromagnetic DC voltage relay installed on the first DC power bus is denoted by J _I , and the electromagnetic DC voltage relay installed on the second DC power bus The DC voltage relay is denoted by J _II , and by analogy, the electromagnetic DC voltage relay installed on the N-section DC power bus is denoted by J _N ;

The fourth step is to sort the transformers in the substation. The first transformer is represented by T1; For the corresponding buttons, the button of the first transformer is represented by _ANT1 , the button of the second transformer is represented by _ANT2 , and so on, the button of the Mth transformer is represented by AN _TM ;

In the fifth step and the third step, the normally closed contacts of the electromagnetic DC voltage relay J _I installed on the first section of the DC power bus are represented by J _IT1 , J _IT2 ... J _ITM , and the electromagnetic type installed on the second section of the DC power bus The normally closed contacts of the DC voltage relay J _II are represented by J _IIT1 , J _IIT2 ... J _IITM , and the normally closed contacts of the electromagnetic DC voltage relay J _N installed on the DC power bus of the Nth segment are represented by J _NT1 , J _NT2 ... J _NTM express

The sixth step is to obtain the voltage setting value U _ZL for the disappearance of the DC power bus section, and the setting values for the disappearance of all DC power bus sections are the same;

The seventh step is to set the electromagnetic DC voltage relay installed on each section of the DC power bus according to the setting value U _ZL obtained in the sixth step; the number of normally closed contacts of the relay should be the same as the number of transformers in the entire substation; the DC power supply voltage is normal , the relay acts and the normally closed contact opens;

Step 8. Configure one supercapacitor for each transformer in the substation; the supercapacitor should be installed near the circuit breaker, and the capacity of the supercapacitor should meet the requirements that all circuit breakers on each side of the transformer can trip reliably at the same time; With super capacitor charging device;

Step 9: When the voltage U _I of the first DC power bus ≦ U _ZL , the electromagnetic DC voltage relay J I installed on the first DC power bus loses the DC power supply, and the electromagnetic DC voltage relay J _I installed on the first DC power bus The normally closed contacts J _IT1 , J _IT2 ... J _ITM of the voltage relay J _I are closed;

Start to judge whether the second section of the DC power bus is de-energized:

If U _II >U _ZL , the electromagnetic DC voltage relay J _II installed on the second DC power bus does not lose the DC power, the normally closed contact J of the electromagnetic DC voltage relay J _II installed on the second DC power bus _IIT1 , J _IIT2 ... J _IITM is not closed, stop judging whether the DC power supply of other buses is lost or not;

If, U _II ≦ U _Z , the electromagnetic DC voltage relay J _II installed on the second DC power bus loses DC power, the normally closed contact J _IIT1 of the electromagnetic DC voltage relay J _II installed on the second DC power bus , J _IIT2 ... J _IITM closed;

Then start to judge whether the third section of the DC power bus is de-energized;

By analogy, it is judged whether the N section DC power supply bus is de-energized; if all the DC power supplies in the substation are in the disappearance state, then the first section DC power supply bus 1 to the electromagnetic DC power supply on the Nth section DC power supply bus The contacts of the voltage relay are all in the closed state;

The tenth step, close the transformer heavy gas relay or pressure release contact, connect the super capacitor of the transformer, use the super capacitor, DC bus electromagnetic DC voltage relay contact of all voltage levels, transformer heavy gas relay or pressure release contact, current limit The circuit formed by the resistance, the closing auxiliary contact of the circuit breaker on each side of the transformer and the tripping coil of the circuit breaker on each side of the transformer supplies power for the tripping coil of the circuit breaker to achieve the purpose of disconnecting the circuit breaker on each side of the transformer;

It can also be activated by pressing the button, the button, the DC bus electromagnetic DC voltage relay contact of all voltage levels, the transformer heavy gas relay or pressure release contact, the current limiting resistor, the auxiliary contact of the circuit breaker on each side of the transformer (connected when the circuit breaker is closed) The loop formed by the circuit breaker tripping coils on each side of the transformer and the circuit breaker tripping coils supplies power to the circuit breaker tripping coils to achieve the purpose of disconnecting the circuit breakers on each side of the transformer.

The voltage setting value U _ZL lost by the DC bus power supply voltage is calculated according to the following formula:

U _ZL =(0.1-0.3) U _n ;

Among them, U _n is the rated voltage of the DC bus power supply.

The DC bus power supply and circuit breaker involved in the above method can also be in the power plant.

The invention provides a simple and effective emergency tripping method for power plants and transformer substations after the DC power supply disappears, and is especially suitable for on-site operators to operate and use, and well guarantees the equipment safety of the transformer substations.

Description of drawings

Fig. 1 is a schematic diagram of wiring of the present invention in a substation system.

Detailed ways

The present invention is described in detail below according to accompanying drawing:

A control circuit for emergency tripping of a circuit breaker after a DC power supply completely disappears, including a trip coil 8 of a circuit breaker on the high voltage side, a first auxiliary contact 7 of the circuit breaker on the high voltage side, a second auxiliary contact 24 of the circuit breaker on the high voltage side, and a circuit breaker on the medium voltage side in a substation Trip coil 10 of the circuit breaker on the medium voltage side 9 Second auxiliary contact 25 of the circuit breaker on the medium voltage side 12 Trip coil 12 of the circuit breaker on the low voltage side Two auxiliary contacts 26; a DC power bus is provided in the substation, and a DC power bus electromagnetic voltage relay is connected between the positive and negative poles of the DC power bus, and one end of the normally closed contact of the DC power bus electromagnetic voltage relay is connected to the supercapacitor 1 One pole of the DC power bus electromagnetic voltage relay is connected together, the other end of the normally closed contact of the DC power bus electromagnetic voltage relay is connected with the parallel connection point B, the transformer pressure release contact 2, the transformer heavy gas relay contact 3 and the button 4 are connected in parallel to form a switch parallel branch One end of the switch parallel branch is connected to the other pole of the supercapacitor 1, and the other end of the switch parallel branch is connected to another parallel node A; one end of the high-voltage side circuit breaker trip coil 8 passes through the high-voltage side The first auxiliary contact 7 of the circuit breaker is connected together with another parallel connection point A, and the other end of the trip coil 8 of the high-voltage side circuit breaker is connected with the parallel connection point B after passing through the second auxiliary contact 24 of the high-voltage side circuit breaker; One end of the trip coil 10 of the circuit breaker on the medium voltage side passes through the first auxiliary contact 9 of the circuit breaker on the medium voltage side and is connected to another parallel connection point A, and the other end of the trip coil 10 of the circuit breaker on the medium voltage side passes through the first The second auxiliary contact 25 is then connected to the parallel connection point B; one end of the trip coil 12 of the low-voltage side circuit breaker is connected to another parallel connection point A after passing through the first auxiliary contact 11 of the low-voltage side circuit breaker, and the low-voltage side circuit breaker trips The other end of the coil 12 is connected to the parallel connection point B after passing through the second auxiliary contact 26 of the low-voltage side circuit breaker.

All of the circuit breaker trip coils and DC power bus bars mentioned above are also part of the equipment of the power plant.

A control method for emergency tripping of a circuit breaker after all DC power sources disappear, comprising the following steps:

The first step is to sort the DC power busbars in the substation. The first DC power busbar is represented by I, the second DC power busbar is represented by II, and so on, the Nth DC power busbar is represented by N;

In the second step, the voltage of the first section of the DC power supply bus is represented by U _I ; the voltage of the second section of the DC power supply bus is represented by U _II ; and so on, the Nth section of the DC power supply bus is represented by U _N ;

The third step is to install an electromagnetic DC voltage relay on each DC power bus. The electromagnetic DC voltage relay installed on the first DC power bus is denoted by J _I , and the electromagnetic DC voltage relay installed on the second DC power bus The DC voltage relay is denoted by J _II , and by analogy, the electromagnetic DC voltage relay installed on the N-section DC power bus is denoted by J _N ;

The fourth step is to sort the transformers in the substation. The first transformer is represented by T1; the second transformer is represented by T2; and so on, the Mth transformer is represented by TM; in the control room, install and For the corresponding button, the button of the first transformer is represented by _ANT1 , the button of the second transformer is represented by _ANT2 , and so on, the button of the Mth transformer is represented by AN _TM ;

In the fifth step and the third step, the normally closed contacts of the electromagnetic DC voltage relay J _I installed on the first section of the DC power bus are represented by J _IT1 , J _IT2 ... J _ITM , and the electromagnetic type installed on the second section of the DC power bus The normally closed contacts of the DC voltage relay J _II are represented by J _IIT1 , J _IIT2 ... J _IITM , and the normally closed contacts of the electromagnetic DC voltage relay J _N installed on the DC power bus of the Nth segment are represented by J _NT1 , J _NT2 ... J _NTM express

The sixth step is to obtain the voltage setting value U _ZL for the disappearance of the DC power bus section, and the setting values for the disappearance of all DC power bus sections are the same;

The seventh step is to set the electromagnetic DC voltage relay installed on each section of the DC power bus according to the setting value U _ZL obtained in the sixth step; the number of normally closed contacts of the relay should be the same as the number of transformers in the entire substation; the DC power supply voltage is normal When (currently the DC bus voltage of power plants and substations is generally 220V or 110V), the relay operates and the normally closed contact opens;

Step 8: Configure one supercapacitor 1 for each transformer in the substation; supercapacitor 1 should be installed near the circuit breaker, and the capacity of the supercapacitor should meet the requirements that all circuit breakers on each side of the transformer can trip reliably at the same time; supercapacitor 1 A supercapacitor charging device 23 is arranged on it to charge the supercapacitor 1;

Step 9: When the voltage U _I of the first DC power bus ≦ U _ZL , the electromagnetic DC voltage relay J I installed on the first DC power bus loses the DC power supply, and the electromagnetic DC voltage relay J _I installed on the first DC power bus The normally closed contacts J _IT1 , J _IT2 ... J _ITM of the voltage relay J _I are closed;

Start to judge whether the second section of the DC power bus is de-energized:

If U _II >U _ZL , the electromagnetic DC voltage relay J _II installed on the second DC power bus does not lose the DC power, the normally closed contact J of the electromagnetic DC voltage relay J _II installed on the second DC power bus _IIT1 , J _IIT2 ... J _IITM is not closed, stop judging whether the DC power supply of other buses is lost or not;

If, U _II ≦ U _Z , the electromagnetic DC voltage relay J _II installed on the second DC power bus loses DC power, the normally closed contact J _IIT1 of the electromagnetic DC voltage relay J _II installed on the second DC power bus , J _IIT2 ... J _IITM closed;

Then start to judge whether the third section of the DC power bus is de-energized;

By analogy, it is judged whether the N section DC power supply bus is de-energized; if all the DC power supplies in the substation are in the disappearance state, then the first section DC power supply bus 1 to the electromagnetic DC power supply on the Nth section DC power supply bus The contacts of the voltage relay are all in the closed state;

The tenth step, close the transformer heavy gas relay or pressure release contact, connect the super capacitor 1 of the transformer, use the super capacitor 1, the DC bus electromagnetic DC voltage relay contact of all voltage levels, the transformer heavy gas relay or pressure release contact, The circuit composed of the current limiting resistor, the closing auxiliary contact of the circuit breaker on each side of the transformer (connected when the circuit breaker is closed and disconnected when the circuit breaker is opened) and the trip coil of the circuit breaker on each side of the transformer supplies power for the trip coil of the circuit breaker, reaching The purpose of opening the circuit breakers on each side of the transformer;

It can also be activated by pressing button 4, button 4, DC bus electromagnetic DC voltage relay contact of all voltage levels, transformer heavy gas relay or pressure release contact, current limiting resistor, auxiliary contact of circuit breaker closing on each side of transformer (circuit breaker closing It is connected when the circuit breaker is open and disconnected when the circuit breaker is open) and the circuit breaker trip coil on each side of the transformer, which supplies power to the trip coil of the circuit breaker to achieve the purpose of disconnecting the circuit breaker on each side of the transformer.

The voltage setting value U _ZL lost by the DC bus power supply voltage is calculated according to the following formula:

U _ZL =(0.1-0.3) U _n ;

Among them, U _n is the rated voltage of the DC bus power supply.

The DC bus power supply and circuit breaker involved in the above method can also be in the power plant.

Claims (4)

1. A circuit breaker emergency trip control circuit after all DC power disappears, including the trip coil (8) of the high-voltage side circuit breaker in the substation, the first auxiliary contact (7) of the high-voltage side circuit breaker, and the second auxiliary contact of the high-voltage side circuit breaker (24), medium voltage side circuit breaker trip coil (10), medium voltage side circuit breaker first auxiliary contact (9), medium voltage side circuit breaker second auxiliary contact (25), low voltage side circuit breaker trip coil (12) , the first auxiliary contact (11) of the low-voltage side circuit breaker, and the second auxiliary contact (26) of the low-voltage side circuit breaker; a DC power bus bar is set in the substation, and it is characterized in that the positive and negative poles of the DC power bus bar are connected with DC power bus electromagnetic voltage relay, one end of the normally closed contact of the DC power bus electromagnetic voltage relay is connected with one pole of the supercapacitor (1), and the other end of the normally closed contact of the DC power bus electromagnetic voltage relay is connected with the parallel connection point (B) Connected together, the transformer pressure release contact (2), the transformer heavy gas relay contact (3) and the button (4) are connected in parallel to form a switch parallel branch, and one end of the switch parallel branch is connected to the other end of the supercapacitor (1). One pole is connected together, the other end of the parallel branch of the switch is connected with another parallel connection point (A); one end of the trip coil (8) of the high voltage side circuit breaker passes through the first auxiliary contact (7) of the high voltage side circuit breaker It is connected with another parallel connection point (A), and the other end of the trip coil (8) of the high voltage side circuit breaker is connected with the parallel connection point (B) after passing through the second auxiliary contact (24) of the high voltage side circuit breaker; One end of the trip coil (10) of the circuit breaker on the medium voltage side is connected to another parallel connection point (A) through the first auxiliary contact (9) of the circuit breaker on the medium voltage side, and the other end of the trip coil (10) of the circuit breaker on the medium voltage side One end passes through the second auxiliary contact (25) of the circuit breaker on the medium voltage side and is connected to the parallel connection point (B); one end of the trip coil (12) of the circuit breaker on the low voltage side passes through the first auxiliary contact (11) of the circuit breaker on the low voltage side It is connected with another parallel connection point (A), and the other end of the trip coil (12) of the low-voltage side circuit breaker is connected with the parallel connection point (B) after passing through the second auxiliary contact (26) of the low-voltage side circuit breaker. 2. The circuit breaker emergency trip control circuit after all DC power disappears according to claim 1, characterized in that, between another parallel node (A) and the first auxiliary contact (7) of the high-voltage side circuit breaker A high-voltage side current-limiting resistor (6) is set; a medium-voltage side current-limiting resistor (5) is set between another parallel connection point (A) and the first auxiliary contact (9) of the medium-voltage side circuit breaker; A low-voltage side current limiting resistor (13) is arranged between the parallel connection point (A) and the first auxiliary contact point (11) of the low-voltage side circuit breaker. 3. The circuit breaker emergency trip control circuit after all DC power sources disappear according to claim 2, characterized in that, the substation is provided with a first section of DC power supply bus (17), a second section of DC power supply bus ( 18) Up to the Nth DC power supply busbar (19) consisting of multiple sets of DC power supply busbars, the first DC power supply busbar electromagnetic voltage relay ( 20), between the positive and negative poles of the second DC power bus (18) is connected a second DC power bus electromagnetic voltage relay (21), until the positive and negative poles of the Nth DC power bus (19) There are electromagnetic voltage relays (22) on the Nth section of the DC power bus, the normally closed contacts (16) of the first section of the DC power bus electromagnetic voltage relay, and the normally closed contacts (15) of the second section of the DC power bus electromagnetic voltage relay. , until the Nth DC power supply bus electromagnetic voltage relay normally closed contacts (14) are connected in series to form a normally closed contact series branch, one end of the normally closed contact series branch is connected with a pole of the supercapacitor (1), normally The other end of the closed contact series branch is connected to the parallel junction (B). 4. The control circuit for emergency tripping of the circuit breaker after the DC power completely disappears according to claim 2, characterized in that a charging device (23) is connected to both ends of the supercapacitor (1).