10kV auxiliary power spare power automatic switching and spare power switching switching-on interlocking optimization loop

Abstract

The utility model discloses a 10kV auxiliary power spare power automatic switching and spare power switching closing interlocking optimization loop which comprises a bus voltage monitoring relay contact, a bus tie circuit breaker position contact, a circuit breaker body closing interlocking mechanism and a circuit breaker interlocking loop monitoring relay. The bus voltage monitoring relay contact is a closed contact of the bus voltage monitoring relay in a bus non-voltage state, and the bus bus tie circuit breaker position contact is a closed contact of the bus tie circuit breaker in an opening state; the bus voltage monitoring relay contact, the bus tie circuit breaker position contact and the circuit breaker body closing interlocking mechanism are connected in series, and the circuit breaker body closing interlocking mechanism is connected with the circuit breaker interlocking loop monitoring relay in parallel; and a pair of normally open contacts of the circuit breaker interlocking loop monitoring relay are used as circuit breaker closing interlocking release contacts and are connected to a switching value input channel of the spare power automatic switching device. The loop can ensure that the spare power switching-on sending time of the spare power automatic switching device is synchronous with the switching-on interlocking releasing time of the circuit breaker.

Description

Technical Field

[0001] The utility model relates to the technical field of self - switching devices, in particular to an optimized circuit for the closing interlock of the 10kV auxiliary power supply self - switching device. Background Technique

[0002] The 10kV auxiliary power supply system is a key device for the long - term and large - load stable operation of the generator set in the power plant. The power supply reliability requirements for the 10kV auxiliary power supply system are extremely high. If a section of the 10kV auxiliary power supply fails to lose power normally due to reasons, its self - switching device (i.e., the standby power supply automatic input device) must perform a reliable self - switching action to input the standby power supply and avoid permanent power loss of this section of the auxiliary power supply.

[0003] However, in actual applications, due to the influence of the load situation on the decay of the bus residual voltage, and there are significant differences in the voltage detection principles of the self - switching device and the voltage relay, the time when the self - switching device issues the closing command and the time when the circuit breaker closing interlock is released are often out of sync. If the time when the circuit breaker closing interlock is released is later than the time when the self - switching device issues the closing command, the circuit breaker will not be able to close successfully, and the self - switching device self - switching fails, resulting in an ineffective action of the self - switching device. Content of the Utility Model

[0004] Aiming at the actual operation problem that the time when the self - switching device issues the closing command and the time when the circuit breaker closing interlock is released are out of sync, the utility model proposes an optimized circuit for the closing interlock of the 10kV auxiliary power supply self - switching device. By optimizing the closing interlock circuit of the 10kV auxiliary power supply circuit breaker, taking the released state of the closing interlock as one of the conditions for the self - switching closing logic, it can not only monitor the state of the circuit breaker closing interlock circuit in real time through the self - switching device, but also ensure the synchronization of the time when the self - switching device issues the closing command and the time when the circuit breaker closing interlock is released.

[0005] The technical solution adopted by the utility model is as follows:

[0006] An optimized circuit for the closing interlock of the 10kV auxiliary power supply self - switching device includes: the contact of the bus voltage monitoring relay, the contact of the bus sectional breaker position, the circuit breaker body closing interlock mechanism, and the circuit breaker interlock circuit monitoring relay. The contact of the bus voltage monitoring relay is the closed contact of the bus voltage monitoring relay in the state of no voltage on the bus. The contact of the bus sectional breaker position is the closed contact of the sectional breaker in the open state; the contact of the bus voltage monitoring relay, the contact of the bus sectional breaker position, and the circuit breaker body closing interlock mechanism are connected in series, and the circuit breaker body closing interlock mechanism is connected in parallel with the circuit breaker interlock circuit monitoring relay; a pair of normally open contacts of the circuit breaker interlock circuit monitoring relay are used as the circuit breaker closing interlock release contacts, and the circuit breaker closing interlock release contacts are connected to the switch - quantity input channel of the self - switching device.

[0007] Further, it further includes an SR bistable flip-flop. The S terminal of the SR bistable flip-flop is electrically connected to the closing of the standby power supply device, and the R terminal is electrically connected to the overall startup control terminal of the standby power supply device.

[0008] Further, it further includes a first AND gate circuit. The first input terminal of the first AND gate circuit is electrically connected to the Q terminal (i.e., the output terminal) of the SR bistable flip-flop, and the second input terminal is electrically connected to the breaker closing interlock release contact.

[0009] Further, the output terminal of the first AND gate circuit can drive the outlet relay of the standby power supply device to output a pulse for closing the breaker by the standby power supply device.

[0010] Further, it further includes a second AND gate circuit. The first input terminal of the second AND gate circuit is electrically connected to the output terminal of the first AND gate circuit, the second input terminal is connected to the voltage when the bus is energized, and the output terminal can output a standby power supply device standby power supply successful signal.

[0011] Further, the value range of the bus energized setting value includes: 80% Un, where Un is the rated voltage of the secondary side of the bus voltage transformer.

[0012] Further, the value range of the setting value U1 of the no-voltage setting of the bus voltage monitoring relay includes: 25% Un, where Un is the rated voltage of the secondary side of the bus voltage transformer.

[0013] Further, the range of taking the bus sectional breaker position contact includes: the auxiliary contact of the breaker body mechanism.

[0014] Further, the selection range of the breaker interlock circuit monitoring relay includes: voltage type relay.

[0015] Further, the action voltage setting range of the breaker interlock circuit monitoring relay includes: 55% - 70% of the rated working voltage of the standby power supply device standby power supply closing interlock optimization circuit.

[0016] The beneficial effects of the present utility model are as follows:

[0017] By optimizing the 10kV auxiliary power supply breaker closing interlock circuit, taking the closing interlock release state as one of the conditions for the standby power supply device standby power supply closing logic, the present utility model can not only realize the real-time monitoring of the breaker closing interlock circuit state by the standby power supply device, but also solve the actual operation problem that the time when the standby power supply device issues the standby power supply closing is not synchronized with the breaker closing interlock release time. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of a 10kV auxiliary power supply standby power supply closing interlock optimization circuit according to an embodiment of the present utility model.

[0019] Figure 2 It is a schematic diagram of the closing logic of the 10kV auxiliary power supply automatic switching device in the embodiment of the present utility model.

[0020] Reference numerals: DYJ is the bus voltage monitoring relay, DYJ1 is the contact of the bus voltage monitoring relay, WZJ is the position contact of the bus-tie breaker, RL is the closing interlock mechanism of the breaker body, KV is the monitoring relay of the breaker interlock circuit, KV-1 is the breaker closing interlock release contact, BZT is the automatic switching device, SR is the SR bistable flip-flop, &-1 is the first AND gate circuit, &-2 is the second AND gate circuit. Specific embodiments

[0021] In order to have a clearer understanding of the technical features, objectives, and effects of the present utility model, the specific embodiments of the present utility model will now be described. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model, that is, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative efforts fall within the protection scope of the present utility model.

[0022] As Figure 1 shown, this embodiment provides an optimized circuit for the closing interlock of the 10kV auxiliary power supply automatic switching device, including the contact DYJ-1 of the bus voltage monitoring relay, the position contact WZJ of the bus-tie breaker, the closing interlock mechanism RL of the breaker body, and the monitoring relay KV of the breaker interlock circuit. The closing interlock circuit of the 10kV auxiliary power supply breaker is optimized by electrically connecting the monitoring relay KV of the breaker interlock circuit in parallel to the closing interlock mechanism RL of the breaker body.

[0023] It should be noted that the original closing interlock circuit of the 10kV auxiliary power supply breaker is composed of the series electrical connection of the contact DYJ-1 of the bus voltage monitoring relay, the position contact WZJ of the bus-tie breaker, and the closing interlock mechanism RL of the breaker body, where the contact DYJ-1 of the bus voltage monitoring relay, the position contact WZJ of the bus-tie breaker, and the closing interlock mechanism RL of the breaker body are connected in series electrically; the contact DYJ-1 of the bus voltage monitoring relay is the closed contact of the bus voltage monitoring relay DYJ in the state of no voltage on the bus. Usually, the set no-voltage value U1 of the bus voltage monitoring relay is 25% Un, and Un is the rated secondary voltage of the bus voltage transformer; the position contact WZJ of the bus-tie breaker is the closed contact in the state of the bus-tie breaker being open, usually taken from the auxiliary contact of the breaker body mechanism.

[0024] Based on this, the optimization of the closing interlock circuit of the 10kV auxiliary power breaker in this embodiment is achieved by connecting the RL of the closing interlock mechanism of the breaker body in parallel with the monitoring relay KV of the breaker interlock circuit. The monitoring relay KV of the breaker interlock circuit can be a voltage-type relay, and the operating voltage is preferably 55%-70% Un.

[0025] Preferably, a pair of normally open contacts of the monitoring relay KV of the breaker interlock circuit is selected as the breaker closing interlock release contact KV-1, and the breaker closing interlock release contact KV-1 is connected to the digital input channel of the backup power automatic switching device BZT.

[0026] As Figure 2 shown is the closing logic of the 10kV auxiliary power backup power automatic switching device in this embodiment. Among them, the closing of the backup power automatic switching device 1 is connected to the S terminal of the SR bistable flip-flop, and the whole-group start 2 is connected to the R terminal of the SR bistable flip-flop through a NOT gate circuit; the output Q terminal of the SR bistable flip-flop is connected to the first input terminal of the first AND gate circuit, and the breaker closing interlock release KV-1 is connected to the second input terminal of the first AND gate circuit; the output terminal of the first AND gate circuit drives the output relay of the backup power automatic switching device BZT to output the pulse for closing the breaker by the backup power automatic switching device; the output terminal of the first AND gate circuit is connected to the first input terminal of the second AND gate circuit, and the bus voltage available 3 is connected to the second input terminal of the second AND gate circuit. The bus voltage available setting value is preferably 80% of the rated voltage of the bus voltage transformer.

[0027] Preferably, the closing logic of the backup power automatic switching device BZT in this embodiment is as follows:

[0028] 1. Under the condition of normal 10kV auxiliary power bus voltage, the following working steps are adopted:

[0029] 1. The bus voltage monitoring relay DYJ monitors that the bus voltage does not reach the no-voltage setting value of 25% Un, the bus voltage monitoring relay DYJ does not operate, its contact DYJ-1 is in the open state, the monitoring relay KV of the breaker interlock circuit does not operate, and the breaker closing interlock release contact KV-1 is in the open state.

[0030] 2. In the 10kV auxiliary power backup power automatic switching closing logic, the second input terminal of the first AND gate circuit, the breaker closing interlock release KV-1, is 0, the first AND gate circuit outputs 0, the pulse output for closing the breaker by the backup power automatic switching device is 0, and the backup power automatic switching device does not operate.

[0031] 2. Under the condition of normal loss of voltage of the 10kV auxiliary power bus, the following working steps are adopted:

[0032] 1. When the 10kV auxiliary power busbar loses voltage normally, the bus voltage monitoring relay DYJ monitors that the bus voltage reaches the no-voltage setting value of 25% Un. The bus voltage monitoring relay DYJ operates, and its contact DYJ-1 is in the closed state. Also, the bus sectional breaker position contact WZJ is in the closed state. The bus breaker interlock circuit monitoring relay KV operates, and the breaker closing interlock release contact KV-1 is in the closed state, that is, the second input terminal of the first AND gate circuit is 1.

[0033] 2. When the 10kV auxiliary power busbar loses voltage normally, the backup power supply automatic switching device BZT monitors a sudden change in the bus voltage. The backup power supply automatic switching device BZT starts as a whole 2 and operates. The output of the whole start 2 is 1. After passing through the NOT gate circuit, the output becomes 0, that is, the R terminal of the SR flip-flop is 0.

[0034] 3. When the voltage of the 10kV auxiliary power busbar decays to the no-voltage setting value of 25% Un of the backup power supply automatic switching logic and there is an available standby power supply for the de-energized busbar, the output of the backup power supply automatic switching close breaker 1 is 1, that is, the S terminal of the SR flip-flop is 1.

[0035] 4. When the R terminal of the SR flip-flop is 0 and the S terminal of the SR flip-flop is 1, the output Q terminal of the SR flip-flop is 1, that is, the first input terminal of the first AND gate circuit is 1.

[0036] 5. When the first input terminal of the first AND gate circuit is 1 and the second input terminal of the first AND gate circuit is 1, the first AND gate circuit outputs 1.

[0037] 6. When the first AND gate circuit outputs 1, the backup power supply automatic switching close breaker pulse output is 1, and the backup power supply automatic switching operates, that is, the first input terminal of the second AND gate circuit is 1.

[0038] 7. When the backup power supply automatic switching operates and the breaker closing interlock is in the released state at this time, the breaker closes normally. The voltage of the 10kV auxiliary power busbar returns to normal, and the bus voltage reaches the voltage setting value of 80% Un. The bus voltage available 3 outputs 1, that is, the second input terminal of the second AND gate circuit is 1.

[0039] 8. When the first input terminal of the second AND gate circuit is 1 and the bus voltage available 3 is 1, the backup power supply automatic switching success is 1, and the backup power supply automatic switching device BZT reports the backup power supply automatic switching success signal.

[0040] 9. The backup power supply automatic switching device BZT whole start 2 is set to return with a time delay. The time delay setting principle is to directly set 5 - 10S or to set according to the longest time from the normal loss of voltage of the busbar to the success of the backup power supply automatic switching multiplied by the reliability coefficient. When the time delay value is reached after the whole start 2, the whole start 2 is 0. The whole start 2 passes through the NOT gate circuit and the output is 1, that is, the R terminal of the SR flip-flop is 1.

[0041] 10. When the success of the backup power supply automatic switching is 1 and the voltage of the 10 kV auxiliary power bus returns to normal, and the closing of the backup power supply automatic switching 1 is 0, that is, the S terminal of the SR bistable flip-flop is 0.

[0042] 11. When the R terminal of the SR bistable flip-flop is 1 and the S terminal of the SR bistable flip-flop is 0, the output Q terminal of the SR bistable flip-flop is 0, that is, the backup power supply automatic switching logic returns to the initial state.

[0043] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. And the changes and alterations made by those skilled in the art without departing from the spirit and scope of the present invention should fall within the protection scope of the appended claims of the present invention.

Claims

1. An optimized loop for the closing and tripping interlock of the 10kV auxiliary power supply automatic switching device, characterized in that Including: The contact of the bus voltage monitoring relay, the position contact of the bus-tie breaker of the bus, the closing interlocking mechanism of the breaker body, and the monitoring relay of the breaker interlocking circuit. The contact of the bus voltage monitoring relay is the closed contact of the bus voltage monitoring relay in the state of no voltage on the bus. The position contact of the bus-tie breaker of the bus is the closed contact of the bus-tie breaker in the open state. The contact of the bus voltage monitoring relay, the position contact of the bus-tie breaker of the bus, and the closing interlocking mechanism of the breaker body are connected in series. The closing interlocking mechanism of the breaker body is connected in parallel with the monitoring relay of the breaker interlocking circuit. A pair of normally open contacts of the monitoring relay of the breaker interlocking circuit serve as the breaker closing interlock release contacts, and the breaker closing interlock release contacts are connected to the digital input channel of the backup power supply automatic switching device.

2. An optimized loop for the closing and tripping interlock of the 10 kV auxiliary power supply automatic switching device according to claim 1, characterized in that, It further includes an SR bistable flip-flop. The S terminal of the SR bistable flip-flop is electrically connected to the closing of the backup power supply of the backup power supply automatic switching device, and the R terminal is electrically connected to the overall start control terminal of the backup power supply automatic switching device.

3. An optimized circuit for the closing and tripping interlock of the 10 kV auxiliary power supply automatic switching device according to claim 2, characterized in that, It further includes a first AND gate circuit. The first input terminal of the first AND gate circuit is electrically connected to the Q terminal (i.e., the output terminal) of the SR bistable flip-flop, and the second input terminal is electrically connected to the breaker closing interlock release contacts.

4. An optimized circuit for the closing and tripping interlock of the 10 kV auxiliary power supply automatic switching device according to claim 3, characterized in that The output terminal of the first AND gate circuit can drive the outlet relay of the backup power supply automatic switching device to output a pulse for the backup power supply automatic switching device to switch on and close the breaker.

5. An optimized loop for the closing and tripping interlock of the 10 kV auxiliary power supply automatic switching device according to claim 4, characterized in that It further includes a second AND gate circuit. The first input terminal of the second AND gate circuit is electrically connected to the output terminal of the first AND gate circuit, the second input terminal is connected to the voltage when the bus is energized, and the output terminal can output a signal indicating the successful switching of the backup power supply automatic switching device.

6. An optimized circuit for the interlocking of closing and tripping of the 10 kV auxiliary power supply automatic switching device according to claim 5, characterized in that, The value range of the set value of the bus energized voltage includes: 80% Un, where Un is the rated secondary voltage of the bus voltage transformer.

7. An optimized loop for the closing and tripping interlock of the 10 kV auxiliary power supply automatic switching device according to claim 1, characterized in that, The value range of the set value of the no-voltage value U1 set by the bus voltage monitoring relay includes: 25% Un, where Un is the rated secondary voltage of the bus voltage transformer.

8. An optimized loop for the closing and tripping interlock of the 10 kV auxiliary power supply automatic switching device according to claim 1, characterized in that, The point-taking range of the position contact of the bus-tie breaker of the bus includes: the auxiliary contact of the breaker body mechanism.

9. An optimized loop for the closing and tripping interlock of the 10 kV auxiliary power supply automatic switching device according to claim 1, characterized in that, The selection range of the monitoring relay of the breaker interlocking circuit includes: voltage-type relay.

10. An optimized circuit for the closing and tripping interlock of the 10 kV auxiliary power supply automatic switching device according to claim 1, characterized in that, The set range of the operating voltage of the monitoring relay of the breaker interlocking circuit includes: 55% - 70% of the rated working voltage of the optimized circuit of the backup power supply automatic switching device for backup power supply switching on and closing interlock.

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