CN109119964B - Intelligent controller to prevent switch trip coil from burning out - Google Patents

Abstract

The invention belongs to the technical field of power system relay protection, and specifically relates to an intelligent controller that prevents switch trip coils from burning out. It solves problems in the circuit breaker trip control loop, mainly to increase the reliability of switch tripping and prevent trip coils from burning out. Intelligent control of the original switch control loop is realized, effectively preventing the burnout of the switch trip coil and the switch refusal accident caused by the switch auxiliary contact. The intelligent controller also provides multiple auxiliary functions such as trip coil disconnection monitoring, circuit breaker auxiliary contact contact reliability monitoring, trip coil temperature monitoring, and closing pulse wave recording at various locations.

Description

Intelligent controller to prevent switch trip coil from burning out

Technical field

The invention belongs to the technical field of power system relay protection, and specifically relates to an intelligent controller that prevents switch tripping coils from burning out. It solves problems in the circuit breaker (switch) tripping control loop, mainly to increase the reliability of switch tripping and prevent tripping. The coil is burned out.

Background technique

At present, the trip contact circuit output by the relay protection device of the power components (lines, transformers, busbars, etc.) of the power system is connected to the switch trip coil circuit to form a switch control circuit. A basic structure is as shown in Figures 1 and 2 of the specification. Show.

In the above switch trip circuit, TBJ is an anti-trip and trip self-holding relay. When the protection trips, the trip relay contact TJ is closed. Through the TBJ relay current coil and the closed circuit breaker auxiliary contact DL, 220 volts are applied to both ends of the trip coil TQ. DC voltage, causing the switch to trip.

During the above tripping process, in order to prevent the switch from refusing to operate due to mechanical jamming of the tripping mechanism, and the fault is removed by the upper level protection, the TJ contact of this protection will return. If no measures are taken, the TJ contact will be burned out due to arcing. In this way, a trip self-holding contact of a TBJ anti-trip relay is connected in parallel at both ends of the trip contact to protect the TJ contact from being burned out.

The introduction of the self-holding contact of the TBJ anti-trip relay brings a problem: once the switch fails to trip, the DL auxiliary contact does not switch and the trip circuit cannot be disconnected, and both ends of the TQ remain charged until burned out.

On the other hand, the introduction of the auxiliary contact of the switch in the trip circuit reduces the reliability of the switch tripping. Once the auxiliary contact of the switch has poor contact, the switch will refuse to operate.

The above-mentioned traditional switch tripping circuit causes accidents of the switch coil being burned and accidents of the switch refusing to operate due to poor contact of the switch auxiliary contact, which occur in large numbers in on-site operations.

Compared with relay protection devices that have become microcomputerized and intelligent, the above-mentioned traditional structure of the switch control loop still remains at the non-intelligent level of decades ago.

Contents of the invention

In order to solve the above technical problems, the present invention provides an intelligent controller that prevents the switch trip coil from burning out.

The invention is implemented as follows: an intelligent controller that prevents switch tripping coils from burning out, including an automatic recovery circuit (1) for DC operating power supply outage, an anti-trip relay self-maintaining state automatic return circuit (3) and an intelligent control module (4 ), the DC operating power supply automatic recovery circuit (1) is connected to the switch trip circuit (2), the switch trip circuit (2) is connected to the anti-trip relay self-maintaining state automatic return circuit (3), and the intelligent control module (4) It is equipped with multiple switching input contacts, multiple analog input contacts, CPU logic operation module, multiple switching output contacts, communication interface and inverter power supply. The DC operating power supply automatic recovery circuit (1) is an inverter power supply. Provide electric energy, and the output contacts in the switch trip circuit (2) and the anti-trip relay self-maintaining state automatic return circuit (3) are connected to the switch input contacts on the intelligent control module (4). The switch trip circuit (2) and anti-trip circuit The analog output in the relay's self-maintaining state automatic return circuit (3) is connected to the analog input contact in the intelligent control module. The switching input and analog input received in the intelligent control module (4) are processed by the CPU logic operation module. , connected to the substation monitoring system through communication interfaces and switching output contacts.

Further, the DC operating power supply automatic recovery circuit (1) includes a battery DC circuit and an AC rectifier output DC circuit. The battery DC circuit starts from the 220V DC positive and negative power terminals C and D, and is connected in sequence to the DC power supply monitoring relay ZJ2. Two normally open contacts, two reverse diodes D3 and D4, and finally output to terminals 201 and 202;

The AC rectifier output DC circuit starts from the A terminal and B terminal connected to the 220V AC power supply, and is sequentially connected to a 220V/160V AC transformer, a rectifier bridge composed of 4 diodes, and 4 capacitors to rectify the 220V AC into 220V DC. Finally, Through the two reverse diodes D1 and D2 and the two normally closed contacts of the DC monitoring relay ZJ2, it is output to terminals 201 and 202;

Connect the DC operating power supply automatic recovery circuit (1) to the switch tripping circuit (2) through terminals 201 and 202.

Further, in the switch trip circuit (2), position points 235, 237 and 239 are set, and three current detection transformers are respectively provided between 235 and 237, between 237 and DL, and between DL and 239.

Further, the anti-trip relay self-maintaining state automatic return circuit (3) includes a switch auxiliary contact test branch, an anti-trip relay self-maintaining state automatic return branch, a trip circuit switch auxiliary contact status monitoring branch, and a trip coil disconnection circuit. Monitoring branch, positive power supply 201 to ground voltage monitoring branch;

The switch auxiliary contact test branch is formed by connecting R1 and output contact SYJ in series and then in parallel between contacts 237 and 239 of the switch trip circuit. R1 is a 110Ω resistor, and the output contact SYJ is a switching output contact in the intelligent control module (4). ;

The anti-jump relay self-maintaining and filling automatic return branch route R2 and the output contact FGJ are connected in series and then in parallel to form between the 201 contact and the 237 contact. R2 is a 0-10Ω variable resistor, and the output contact FGJ is the one in the intelligent control module (4) One switching output contact;

The trip circuit switch auxiliary contact status monitoring branch is formed by the trip circuit switch auxiliary contact status monitoring relay DLJ and the line between contacts 237 and 239. The two DLF contacts are connected in series with the DL contact and then connected in parallel between contacts 237 and 239. DL Between the two DLFs, the two DLF output contacts are the two switching output contacts in the intelligent control module (4);

The trip coil disconnection monitoring branch is formed by the trip coil disconnection monitor DX1 connected in parallel between contact 202 and contact 237. The contact of DX1 is a switching output contact in the intelligent control module (4);

The positive power supply 201-to-ground voltage monitoring branch is formed by connecting the positive power supply 201-to-ground voltage monitoring relay JD1 in parallel between contact 202 and contact 235. The JD1 contact is a switching output contact in the intelligent control module (4).

Further, the contacts 201 and 202 are connected to the inverter power supply of the intelligent control module (4), and the plurality of switch input contacts include a trip outlet backup contact TJ taken from the protection device and a manual trip point taken from the protection switch operating circuit. Relay contact STJ, temperature relay contact WJ installed on the trip coil, anti-trip relay self-maintaining state automatic return circuit (3), trip coil disconnection monitoring relay DX1 output contact DX1, anti-trip relay self-maintaining state automatic return circuit (3) 3) The output contact JD1 of the output negative power supply to ground voltage monitoring relay JD1 and the switch auxiliary contact DL are introduced after the output of the switch mechanism. They are two contacts, one open and one closed;

The analog input contacts include the CT secondary three-phase current IABC and zero sequence current I0 input by the protection device, and the current detection mutual inductance between 235 and 237, between 237 and DL, and between DL and 239 in the switch trip circuit (2) The current I235, I237, I239 output by the device;

In addition to the SYJ, FGJ, two DLF, DX1, and JD1 described in claim 4, the switching output contacts are also provided with alarm switching output contacts.

Compared with the prior art, the advantages of the present invention are:

1. Use intelligent control modules to prevent the switch trip circuit from being charged for a long time and prevent the switch coil TQ from burning out;

2. The intelligent control module will only increase the reliability of tripping, but will not bring negative effects;

3. It has a monitoring circuit for whether the trip circuit is intact, and the resistance value of the trip circuit can be given at any time;

4. It has a trip coil temperature monitoring circuit. When the temperature of the trip coil is too high, an alarm message will be given and the trip circuit will be automatically disconnected for 200 milliseconds and then connected again;

5. It has the function of automatic switching of backup trip power supply. Prevent the switch from refusing to operate due to battery and charger failure;

6. It has tripping pulse recording function: providing analysis basis for finding the cause of switch tripping;

7. It has the function of forcing the switch auxiliary contact to be connected: the intelligent control module has a switch auxiliary contact forced connection button, and its contacts are connected in parallel at both ends of the original switch auxiliary contact. When a control loop disconnection signal appears, the intelligent control module automatically temporarily connects the button contact. If the control loop disconnection disappears, it means that the switch auxiliary contact is not in good contact, and one of the common reasons for the control loop disconnection is automatically determined;

8. It has the function of real-time communication with the substation background monitoring system.

Description of drawings

Figure 1 shows a typical switch tripping circuit in the prior art;

Figure 2 is a simplified switch tripping circuit in the prior art;

Figure 3 shows the automatic recovery circuit for DC operating power supply loss;

Figure 4 is a schematic diagram of the switch trip circuit;

Figure 5 shows the automatic return circuit of the anti-trip relay in its self-maintaining state;

Figure 6 is a schematic structural diagram of the intelligent control module;

Figure 7 is the automatic reset logic block diagram of the anti-trip relay.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

Referring to Figure 3, in order to prevent the switch trip coil from burning out, the DC operating power supply automatic recovery circuit (1) in the intelligent controller is in which the A and B terminals are respectively connected to the 220V AC power supply used in the substation or the external 220V AC power supply. Power supply, the 220V AC power supply passes through a 1000-watt AC transformer with a transformation ratio of 220V/160V. After the voltage is reduced, it passes through a rectifier bridge composed of four diodes G1, G2, G3, and G4 that can pass 10A current, and C1, C2, C3 and C4 are four capacitors with a voltage of 300 volts and a capacity of 2000 microfarads to achieve the purpose of rectifying 220V AC into 220V DC. Finally, through the two normally closed contacts of the reverse diodes D1 and D2 and the DC monitoring relay ZJ2 , output to terminals 201 and 202, which is the AC rectifier output DC circuit;

Terminals C and D are the 220V DC positive and negative power terminals of the substation respectively. C is connected to the 220V positive terminal 101, and D is connected to the 220V negative terminal 102. ZJ2 is the substation DC power supply monitoring relay. When the substation has a normal 220V DC power supply, the ZJ2 relay is in the action state, and 101 and 102 DC are output to 201 and 202 through the two normally open contacts of ZJ2 and the two reverse diodes D3 and D4. terminal, this is the battery DC circuit.

The final function of the DC operating power supply automatic recovery circuit (1) is to convert the 220V AC in the substation into 220V DC with the same voltage as the DC battery pack in the substation through voltage regulation, rectification, and filtering. When the battery DC in the substation has power, the DC switches 201 and 202 use the battery DC. When the battery DC disappears, the DC output from the AC rectifier is used. It solves the problem of how to achieve correct tripping of the switch even when the DC battery power supply of the substation is damaged.

Referring to Figure 4, it is a switch tripping circuit, in which 201 and 202 are the positive and negative terminals of the DC 220V power supply output in Figure 3, TJ is the tripping contact output by the protection device, and TBJ is the original switch control circuit. Anti-trip relay, DL is the switch auxiliary contact (connected when the switch is closed), TQ is the switch trip coil, 235, 237, and 239 are different position points of the trip circuit, I235, I237, and I239 are between 235 and 237 respectively. The current detection transformer between 237 and DL, and between DL and 239, when current flows through this section of wire, the transformer will have a secondary current output.

Refer to Figure 5, which is an automatic return circuit for the self-maintaining state of the anti-trip relay. R1 is 110 ohms, the resistor power is 300W, and it can pass 2A current in a short time. SYJ is the output contact in the intelligent control module. When the switch is in the closing position and an When the control loop is disconnected, the intelligent control module closes the SYJ contact for 10 seconds to see if the control loop disconnection disappears. If it disappears, it is judged that the switch auxiliary contact is in poor contact.

R2 is an adjustable resistor (variable between 0-10 ohms), FGJ is the anti-trip relay self-maintaining state and automatic return relay contact. This node is output by the intelligent control. When the intelligent control module determines that the switch receives the tripping command, after a few seconds, If the protection fault current IABC has disappeared, but the switch auxiliary contact DL has not changed, FGJ will be automatically turned on for a certain period of time and then automatically turned off.

DLJ is the trip circuit switch auxiliary contact status monitoring relay. When the switch is in the closed state, if a DC voltage of more than 110V appears at both ends of the DLJ relay, it means that the switch auxiliary contact is in poor contact. The intelligent control module automatically outputs a pair of contacts DLF to communicate with the external After the DL contacts are connected in series, the trip circuit is forced to be connected to prevent the switch from refusing to operate.

The DX1 relay is a trip coil disconnection monitoring relay. When the trip coil is disconnected, a 220V voltage appears at both ends of the relay and operates. The relay contact DX1 is connected to the intelligent control module, and a trip coil disconnection signal is sent through the intelligent control module.

JD1 is the positive power supply 201 to ground voltage monitoring relay. When the positive power supply is grounded, the relay operates, and the relay contact JD1 is connected to the intelligent control module.

Terminals 201, 202, 235, 237, and 239 in Figure 5 are directly connected to terminals 201, 202, 235, 237, and 239 in Figure 4.

Referring to Figure 6, which is a structural diagram of the intelligent control module, the working power supplies 201 and 202 of the inverter power module are taken from the terminals 201 and 202 of Figure 3. The input contacts of the switch input module: TJ is taken from the trip outlet backup contact of the protection device; STJ is taken from the manual trip relay contact of the protection switch operating circuit; WJ is the temperature relay contact installed on the trip coil; DX1 is the trip point in Figure 5 The output contact of the coil disconnection monitoring relay DX1; JD1 is the contact output of the negative power supply to ground voltage monitoring relay JD1 output in Figure 5; DL is the switch auxiliary contact, introduced after the output of the switch mechanism, with two contacts, one open and one closed.

The input quantities of the analog input module: IABC and I0 are the CT secondary three-phase current input by the protection device, and the zero sequence current, which are used to determine whether the primary current of the switch disappears and whether the switch refuses to operate; I235, I237, and I239 are shown in Figure 4 respectively. The current between 235 and 237, between 237 and DL, and between DL and 239 detects the current output by the transformer. When there is current, it means that there is a tripping pulse in this section of wire, which provides wave recording data for analyzing the cause of switch tripping.

The output contact of the switching output module: FGJ is the self-maintaining state automatic return contact of the anti-trip relay. When the intelligent control module determines that the switch receives the tripping order a few seconds later, the protection fault current IABC has disappeared, but the switch auxiliary contact DL remains unchanged. , the FGJ will be automatically turned on for a certain period of time and then automatically turned off.

DLF is an alternative auxiliary contact output after the switch auxiliary contact is in poor contact. If a DC voltage of more than 110V appears at both ends of the DLJ relay in Figure 5, it means that the switch auxiliary contact is in poor contact. The intelligent control module in Figure 6 automatically outputs a pair of DLF contacts.

The DX1 contact is the trip coil disconnection signal contact output to the substation monitoring system.

JD1 is the DC positive ground monitoring contact, which is output to the substation background monitoring system.

The SYJ contact output is a test contact for judging whether the switch auxiliary contact is in poor contact. When the switch is in the closing position and the control circuit disconnection occurs, the intelligent control module closes the SYJ contact for 10 seconds and then opens it to see if the control loop disconnection disappears during the closing period. If it disappears, it is judged that the switch auxiliary contact is in poor contact.

The alarm contact is the self-operating status monitoring contact output by the intelligent control module. When the CPU logic error, power failure, etc. occurs, the contact is closed and output to the substation background monitoring system to let the operating personnel on duty know.

CPU logic operation module: performs logical operations, analysis, wave recording, etc. on the information of switch input and analog input, and finally makes the switch output module output the corresponding command signal, so that the communication interface module communicates with external connections.

Refer to Figure 7, which is a logic block diagram of the automatic reset of the anti-trip relay. When a short-circuit fault occurs in the system, the switch is initially in the closed position, and the protection trip contact TJ acts to send a trip command to the circuit breaker, or STJ acts when the circuit breaker is manually opened, delayed by T1 The rear switch does not change position T (WJ=0), which proves that the switch refuses to move (the anti-jump self-holding circuit is always active at this time). After the T2 delay, the FGJ relay is driven to act for 100 milliseconds and then returns. 100 milliseconds after the FGJ relay acts. During the millisecond period, the normally closed contact of the FGJ relay is connected in parallel to both ends of the current holding coil of the anti-trip relay TBJ, causing TBJ to lose excitation and reset, and disconnect the trip holding circuit.

After the above-mentioned Figures 3, 4, 5, 6 and 7 are numbered according to the numbers and connected in the manner explained above, intelligent control of the original switch control loop is realized, effectively preventing the burnout of the switch trip coil and the failure of the switch auxiliary The switch refuses to operate due to contact reasons.

The above-mentioned intelligent control module also provides multiple auxiliary functions such as trip coil disconnection monitoring, circuit breaker auxiliary contact contact reliability monitoring, trip coil temperature monitoring, and closing pulse wave recording at various locations.

Claims (2)

1. An intelligent controller that prevents switch tripping coils from burning out, which is characterized by including an automatic recovery circuit (1) for DC operating power supply loss, an anti-trip relay self-maintaining state automatic return circuit (3) and an intelligent control module (4) , the DC operating power supply automatic recovery circuit (1) is connected to the switch trip circuit (2), the switch trip circuit (2) is connected to the anti-trip relay self-maintaining state automatic return circuit (3), and the intelligent control module (4) is equipped with There are multiple switching input contacts, multiple analog input contacts, CPU logic operation modules, multiple switching output contacts, communication interfaces and inverter power supplies. The DC operating power supply loses automatic recovery circuit (1) for the inverter power supply. Electric energy, the output contacts in the switch trip circuit (2), and the anti-trip relay self-maintaining state automatic return circuit (3) are connected to the switch input contacts on the intelligent control module (4), the switch trip circuit (2), and the anti-trip relay The analog output in the self-maintaining state automatic return loop (3) is connected to the analog input contact in the intelligent control module. The switch input and analog input received in the intelligent control module (4) are processed by the CPU logic operation module. Connected to the substation monitoring system through communication interface and switching output contacts; The DC operating power supply automatic recovery circuit (1) includes a battery DC circuit and an AC rectifier output DC circuit. The battery DC circuit starts from the 220V DC positive and negative power terminals C and D, and is sequentially connected to the two normal terminals of the DC power supply monitoring relay ZJ2. Open contact, two reverse diodes D3 and D4, and finally output to terminals 201 and 202; The AC rectifier output DC circuit starts from the A terminal and B terminal connected to the 220V AC power supply, and is sequentially connected to a 220V/160V AC transformer, a rectifier bridge composed of 4 diodes, and 4 capacitors to rectify the 220V AC into 220V DC. Finally, Through the two reverse diodes D1 and D2 and the two normally closed contacts of the DC monitoring relay ZJ2, it is output to terminals 201 and 202; Connect the DC operating power supply automatic recovery circuit (1) to the switch tripping circuit (2) through terminals 201 and 202; In the switch trip circuit (2), position points 235, 237 and 239 are set, and three current detection transformers are respectively provided between 235 and 237, between 237 and DL, and between DL and 239; The anti-trip relay self-maintaining state automatic return circuit (3) includes a switch auxiliary contact test branch, an anti-trip relay self-maintaining state automatic return branch, a trip circuit switch auxiliary contact status monitoring branch, and a trip coil disconnection monitoring branch. , positive power supply 201 to ground voltage monitoring branch; The switch auxiliary contact test branch is formed by connecting R1 and output contact SYJ in series and then in parallel between contacts 237 and 239 of the switch trip circuit. R1 is a 110Ω resistor, and the output contact SYJ is a switching output contact in the intelligent control module (4); The anti-jump relay self-maintaining and filling automatic return branch route R2 and the output contact FGJ are connected in series and then in parallel to form between the 201 contact and the 237 contact. R2 is a 0-10Ω variable resistor, and the output contact FGJ is one of the intelligent control modules (4) Switching output contact; The trip circuit switch auxiliary contact status monitoring branch is formed by the trip circuit switch auxiliary contact status monitoring relay DLJ and the line between contacts 237 and 239. Two DLF contacts are connected in series with the DL contact and then connected in parallel between contacts 237 and 239. DL is in Between the two DLFs, the two DLF output contacts are the two switching output contacts in the intelligent control module (4); The trip coil disconnection monitoring branch is formed by the trip coil disconnection monitor DX1 connected in parallel between contact 202 and contact 237. The contact of DX1 is a switching output contact in the intelligent control module (4); The positive power supply 201-to-ground voltage monitoring branch is formed by connecting the positive power supply 201-to-ground voltage monitoring relay JD1 in parallel between contact 202 and contact 235. The JD1 contact is a switching output contact in the intelligent control module (4). 2. The intelligent controller for preventing the switch trip coil from burning out as claimed in claim 1, characterized in that the contacts 201 and 202 are connected to the inverter power supply of the intelligent control module (4), and the plurality of switching input contacts include The trip outlet backup contact TJ taken from the protection device, the manual trip relay contact STJ taken from the protection switch operating circuit, the temperature relay contact WJ installed on the trip coil, and the anti-trip relay self-maintaining state automatic return circuit (3) trip coil The contact point DX1 of the disconnection monitoring relay DX1 output, the anti-trip relay self-maintaining state automatic return circuit (3) output of the negative power supply to the ground voltage monitoring relay JD1 output contact point JD1, the switch auxiliary contact DL, DL is introduced after the output of the switch mechanism, It has two contacts, one open and one closed; The analog input contacts include the CT secondary three-phase current IABC and zero sequence current I0 input by the protection device, and the current detection mutual inductance between 235 and 237, between 237 and DL, and between DL and 239 in the switch trip circuit (2) The current I235, I237, I239 output by the device; In addition to the aforementioned SYJ, FGJ, two DLF, DX1, and JD1, the switching output contacts are also equipped with alarm switching output contacts.