Standby emergency diesel generating set power supply circuit suitable for high-temperature gas cooled reactor nuclear power plant

Abstract

The invention relates to the technical field of emergency diesel generators of emergency power systems, and discloses a power supply circuit suitable for a standby emergency diesel generator set of a high-temperature gas cooled reactor nuclear power plant, and the power supply circuit is additionally provided with a standby emergency diesel generator which is connected to a working bus through an outlet circuit breaker. A standby diesel generator is connected with a transfer bus through an interconnection switch, the transfer bus is connected to two original emergency buses through feeder switches, and the two emergency buses are additionally provided with wire inlet switches led from the transfer bus, so that when any one original emergency diesel generator fails and is unavailable, the standby diesel generator can quickly replace the original emergency diesel generator to execute an emergency power supply function through switching operation; retreating of the unit operation mode is avoided, and the power generation economy, operation stability and accident safety of the nuclear power plant are improved.

Description

Technical Field

[0001] This invention relates to the field of emergency diesel generator technology in emergency power systems, and specifically to a power supply circuit for a backup emergency diesel generator set suitable for high-temperature gas-cooled reactor nuclear power plants. Background Technology

[0002] The core components of the emergency power system of the high-temperature gas-cooled reactor demonstration project include emergency diesel generator sets (hereinafter referred to as emergency diesel generators) and power distribution systems. Among them, the emergency diesel generators are key emergency power sources. In the event that both the main power source and the auxiliary power source outside the plant fail, they must undertake crucial guarantee functions such as the habitability of the main control room and post-accident monitoring, which are directly related to the safe and stable operation of the nuclear power plant.

[0003] The existing emergency busbar is equipped with two incoming switches: one source is from a 6kV medium-voltage transformer, which is stepped down to 380V by a dry-type transformer, serving as the normal operating power supply for the emergency busbar; the other source is from the emergency diesel generator, serving as an emergency power supply in case the normal power supply is lost. The nuclear power plant's operating technical specifications place extremely high demands on the availability of the emergency diesel generator. However, in actual operation, the emergency diesel generator may face risks such as damage to critical sensitive equipment and components during its lifespan, natural disasters or equipment failures leading to unavailability of external power, and auxiliary transformer maintenance. Once the emergency diesel generator fails, the downtime for return to the plant for repair or troubleshooting is extremely long; the repair and replacement of critical components is estimated to take approximately 300 days. During this period, to ensure the safety of the plant's power supply, the unit must be withdrawn to a hot shutdown state, severely impacting the nuclear power plant's power generation economics. Summary of the Invention

[0004] This invention provides a power supply circuit for backup emergency diesel generator sets in high-temperature gas-cooled reactor nuclear power plants, in order to solve the problem that when an emergency diesel generator fails, the unit needs to be withdrawn to a hot shutdown state, which seriously affects the economic efficiency of nuclear power plant power generation.

[0005] This invention provides a power supply circuit for a backup emergency diesel generator set suitable for high-temperature gas-cooled reactor nuclear power plants. The circuit includes: a backup emergency diesel generator, a backup emergency diesel generator working bus, a backup emergency diesel generator transfer bus, a backup emergency diesel generator output switch, a backup power transfer switch group, a first emergency bus backup power switch group, and a second emergency bus backup power switch group. The backup emergency diesel generator is connected to the backup emergency diesel generator working bus via the backup emergency diesel generator output switch, and the backup emergency diesel generator working bus is connected to the backup emergency diesel generator transfer bus via the backup power transfer switch group. The backup emergency diesel generator transfer bus is connected to the first emergency bus via the first emergency bus backup power switch group, and the backup emergency diesel generator transfer bus is connected to the second emergency bus via the second emergency bus backup power switch group. The first emergency bus is equipped with a first emergency diesel generator, and the second emergency bus is equipped with a second emergency diesel generator.

[0006] This invention provides a power supply circuit for a backup emergency diesel generator set suitable for high-temperature gas-cooled reactor nuclear power plants. By adding a backup emergency diesel generator, which is connected to the working bus via an output circuit breaker and to a transfer bus via a tie switch, the transfer bus is connected to two existing emergency buses via feeder switches. Both emergency buses also have newly added incoming switches from the transfer bus. This invention allows the backup diesel generator to quickly replace any existing emergency diesel generator in case of failure, thus avoiding unit shutdown and improving the economic efficiency, operational stability, and accident safety of the nuclear power plant. In one optional embodiment, the backup power transfer switch group includes: a backup emergency diesel generator to transfer bus tie switch and a transfer bus incoming switch, wherein, One end of the standby emergency diesel generator to transfer bus tie switch is connected to the working bus of the standby emergency diesel generator, the other end of the standby emergency diesel generator to transfer bus tie switch is connected to one end of the transfer bus incoming switch, and the other end of the transfer bus incoming switch is connected to the transfer bus of the standby emergency diesel generator.

[0007] In one optional embodiment, the first emergency bus backup power switch group includes: a switching switch for transferring the bus to the first emergency bus feeder and a first emergency bus backup emergency incoming switch, wherein, One end of the transfer bus to the first emergency bus feeder switch is connected to the backup emergency diesel generator transfer bus, the other end of the transfer bus to the first emergency bus feeder switch is connected to one end of the first emergency bus backup emergency incoming switch, and the other end of the first emergency bus backup emergency incoming switch is connected to the first emergency bus.

[0008] In one optional embodiment, the second emergency bus backup power switch group includes: a switching switch for transferring the bus to the second emergency bus feeder and a second emergency bus backup emergency incoming switch, wherein, One end of the transfer bus to the second emergency bus feeder switch is connected to the backup emergency diesel generator transfer bus, and the other end of the transfer bus to the second emergency bus feeder switch is connected to one end of the backup emergency incoming switch of the second emergency bus, and the other end of the backup emergency incoming switch of the second emergency bus is connected to the second emergency bus.

[0009] In one optional embodiment, the circuit further includes: a backup emergency diesel generator auxiliary power distribution bus, a common busbar feeder switch for the backup emergency diesel generator auxiliary power distribution bus, and a normal incoming switch for the backup emergency diesel generator auxiliary power distribution bus, wherein... The backup emergency diesel generator auxiliary power distribution bus is connected to the plant's common bus via the backup emergency diesel generator auxiliary power distribution bus normal incoming switch and the common bus to the backup emergency diesel generator auxiliary power distribution bus feeder switch. The backup emergency diesel generator auxiliary power distribution bus is equipped with the backup emergency diesel generator auxiliary power distribution load.

[0010] In one optional embodiment, the circuit further includes: a feeder switch from the backup emergency diesel generator working bus to the auxiliary power distribution bus and an emergency incoming switch for the backup emergency diesel generator auxiliary power distribution bus, wherein... The backup emergency diesel generator auxiliary power distribution bus is connected to the backup emergency diesel generator working bus in sequence through the backup emergency diesel generator auxiliary power distribution bus emergency incoming switch and the backup emergency diesel generator working bus to auxiliary power distribution bus feeder switch.

[0011] In one optional implementation, when the backup emergency diesel generator is in standby mode, the first emergency bus backup emergency incoming switch, the second emergency bus backup emergency incoming switch, the transfer bus to first emergency bus feeder switch, the transfer bus to second emergency bus feeder switch, the transfer bus incoming switch, the backup emergency diesel generator to transfer bus tie switch, the backup emergency diesel generator outgoing switch, the backup emergency diesel generator working bus to auxiliary equipment distribution bus feeder switch, and the backup emergency diesel generator auxiliary equipment distribution bus emergency incoming switch are all in an isolated open state. The backup emergency diesel generator auxiliary equipment distribution bus normal incoming switch and the common bus to backup emergency diesel generator auxiliary equipment distribution bus feeder switch are in a closed state. The backup emergency diesel generator auxiliary equipment distribution bus is energized, supplying power to the auxiliary equipment distribution load of the backup emergency diesel generator.

[0012] In one optional implementation, when the standby emergency diesel generator is undergoing periodic testing, the first emergency bus backup incoming switch, the second emergency bus backup emergency incoming switch, the transfer bus to the first emergency bus feeder switch, the transfer bus to the second emergency bus feeder switch, the transfer bus incoming switch, and the standby emergency diesel generator to the transfer bus tie switch are all in an isolated open state. The standby emergency diesel generator working bus to auxiliary equipment distribution bus feeder switch, the standby emergency diesel generator auxiliary equipment distribution bus emergency incoming switch, the standby emergency diesel generator auxiliary equipment distribution bus normal incoming switch, and the common bus to standby emergency diesel generator auxiliary equipment distribution bus feeder switch are in a closed state. When the standby emergency diesel generator starts and the output voltage and frequency reach preset values, the standby emergency diesel generator output switch is connected to the plant's common bus for load bearing through synchronous closing.

[0013] In one optional implementation, when the first emergency diesel generator fails and becomes unavailable, the emergency incoming switch of the first emergency bus, the feeder switch of the public bus to the auxiliary power distribution bus of the backup emergency diesel generator, the normal incoming switch of the auxiliary power distribution bus of the backup emergency diesel generator, the backup emergency incoming switch of the second emergency bus, and the feeder switch of the transfer bus to the second emergency bus are in the isolated open state; the backup emergency incoming switch of the first emergency bus, the feeder switch of the transfer bus to the first emergency bus, the incoming switch of the transfer bus, the tie switch of the backup emergency diesel generator to the transfer bus, the feeder switch of the working bus of the backup emergency diesel generator to the auxiliary power distribution bus, and the emergency incoming switch of the auxiliary power distribution bus of the backup emergency diesel generator are in the closed state; and the output switch of the backup emergency diesel generator is in the working position and closed according to the start signal.

[0014] In one optional implementation, when the second emergency diesel generator fails and becomes unavailable, the emergency incoming switch of the second emergency bus, the feeder switch of the public bus to the auxiliary power distribution bus of the backup emergency diesel generator, the normal incoming switch of the auxiliary power distribution bus of the backup emergency diesel generator, the backup emergency incoming switch of the first emergency bus, and the feeder switch of the transfer bus to the first emergency bus are in the isolated open state; the backup emergency incoming switch of the second emergency bus, the feeder switch of the transfer bus to the second emergency bus, the incoming switch of the transfer bus, the tie switch of the backup emergency diesel generator to the transfer bus, the feeder switch of the working bus of the backup emergency diesel generator to the auxiliary power distribution bus, and the emergency incoming switch of the auxiliary power distribution bus of the backup emergency diesel generator are in the closed state; and the output switch of the backup emergency diesel generator is in the working position and closed according to the start signal. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a power supply circuit for a backup emergency diesel generator set applicable to a high-temperature gas-cooled reactor nuclear power plant, according to an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0019] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] This invention provides a power supply circuit suitable for backup emergency diesel generator sets in high-temperature gas-cooled reactor nuclear power plants, such as... Figure 1 As shown, it includes: a backup emergency diesel generator, a backup emergency diesel generator working busbar BNM, a backup emergency diesel generator transfer busbar BNT, a backup emergency diesel generator output switch BNM.A2, a backup power transfer switch group, a first emergency busbar backup power switch group, and a second emergency busbar backup power switch group.

[0021] The backup emergency diesel generator is connected to the backup emergency diesel generator working bus BNM via the backup emergency diesel generator output switch BNM.A2. The backup emergency diesel generator working bus BNM is connected to the backup emergency diesel generator transfer bus BNT via the backup power transfer switch group. The backup emergency diesel generator transfer bus BNT is connected to the first emergency bus via the first emergency bus backup power switch group, and the backup emergency diesel generator transfer bus BNT is connected to the second emergency bus via the second emergency bus backup power switch group. The first emergency bus is equipped with a first emergency diesel generator, and the second emergency bus is equipped with a second emergency diesel generator.

[0022] Specifically, the backup emergency diesel generator has performance parameters that are fully matched with the original emergency diesel generator, and has the ability to replace any of the original emergency diesel generators to perform emergency power supply functions.

[0023] When the first emergency diesel generator fails and becomes unavailable, the emergency incoming switch BNA.A2 of the first emergency bus and the backup power switch group of the second emergency bus are in the isolated open state, while the backup power switch group and the backup power transfer switch group of the first emergency bus are in the closed state. The backup emergency diesel generator output switch BNM.A2 is in the working position. The backup emergency diesel generator receives the start signal and starts successfully. Once its output voltage and frequency reach the qualified standards, the backup emergency diesel generator output switch BNM.A2 automatically closes, supplying power to the first emergency bus BNA, completely replacing the first emergency diesel generator in performing the predetermined emergency power supply function.

[0024] When the second emergency diesel generator fails and becomes unavailable, the emergency incoming switch BNB.A2 of the second emergency bus and the standby power switch group of the first emergency bus are in the isolated open state, while the standby power switch group and the standby power transfer switch group of the second emergency bus are in the closed state. The standby emergency diesel generator output switch BNM.A2 is in the working position. The standby emergency diesel generator receives the start signal and starts successfully. Once its output voltage and frequency reach the qualified standards, the standby emergency diesel generator output switch BNM.A2 automatically closes, supplying power to the second emergency bus BNB, completely replacing the second emergency diesel generator in performing the predetermined emergency power supply function.

[0025] With the above design, when any of the original emergency diesel generators fails due to a major malfunction, the backup emergency diesel generator can quickly replace the faulty emergency diesel generator and perform its intended functions simply by switching the bus. This effectively avoids the forced shutdown of the unit operation mode of the high-temperature gas-cooled reactor nuclear power plant due to the unavailability of the emergency diesel generator, and significantly improves the power generation economy, operational stability and accident response safety of the nuclear power plant.

[0026] This invention provides a power supply circuit for a backup emergency diesel generator set suitable for high-temperature gas-cooled reactor nuclear power plants. The backup diesel generator is connected to the working bus via an output circuit breaker and to a transfer bus via a tie switch. The transfer bus is connected to two existing emergency buses via feeder switches, and both emergency buses have newly added incoming switches from the transfer bus. This application allows the backup diesel generator to quickly replace any existing emergency diesel generator in case of failure, thus avoiding the need for unit operation mode shutdown and improving the power generation economy, operational stability, and accident safety of the nuclear power plant. In one alternative implementation, such as Figure 1 As shown, the backup power transfer switch group includes: a backup emergency diesel generator to transfer bus tie switch BNM.A3 and a transfer bus incoming switch BNT.A1. One end of the backup emergency diesel generator to transfer bus tie switch BNM.A3 is connected to the backup emergency diesel generator working bus BNM, and the other end of the backup emergency diesel generator to transfer bus tie switch BNM.A3 is connected to one end of the transfer bus incoming switch BNT.A1. The other end of the transfer bus incoming switch BNT.A1 is connected to the backup emergency diesel generator transfer bus BNT.

[0027] Specifically, the backup power transfer switch group uses two switches connected in series to achieve precise on / off control between the backup emergency diesel generator working bus BNM and the backup emergency diesel generator transfer bus BNT. This provides structural support for the stable transmission of power from the working bus to the transfer bus. At the same time, the dual-switch design enhances the safety of the circuit control, avoids the failure of the backup power supply channel due to the failure of a single switch, and ensures the reliability of subsequent power diversion to the first and second emergency buses.

[0028] In one alternative implementation, such as Figure 1 As shown, the first emergency bus backup power switch group includes: a transfer bus to first emergency bus feeder switch BNT.A2 and a first emergency bus backup emergency incoming switch BNA.A3. One end of the transfer bus to first emergency bus feeder switch BNT.A2 is connected to the backup emergency diesel generator transfer bus BNT; the other end of the transfer bus to first emergency bus feeder switch BNT.A2 is connected to one end of the first emergency bus backup emergency incoming switch BNA.A3; and the other end of the first emergency bus backup emergency incoming switch BNA.A3 is connected to the first emergency bus.

[0029] Specifically, the backup power switch group for the first emergency busbar, through a dedicated link design from the transfer busbar to the first emergency busbar feeder switch BNT.A2 and the first emergency busbar backup emergency incoming switch BNA.A3, clearly defines the power transmission path from the backup emergency diesel generator to the first emergency busbar BNA, ensuring that when the first emergency diesel generator fails and becomes unavailable, the backup generator's power can be accurately connected to the target busbar. Combined with the switching operation logic, it can quickly replace the function of the first emergency diesel generator.

[0030] In one alternative implementation, such as Figure 1 As shown, the second emergency bus backup power switch group includes: a transfer bus to second emergency bus feeder switch BNT.A3 and a second emergency bus backup emergency incoming switch BNB.A3. One end of the transfer bus to second emergency bus feeder switch BNT.A3 is connected to the backup emergency diesel generator transfer bus BNT, and the other end of the transfer bus to second emergency bus feeder switch BNT.A3 is connected to one end of the second emergency bus backup emergency incoming switch BNB.A3. The other end of the second emergency bus backup emergency incoming switch BNB.A3 is connected to the second emergency bus.

[0031] Specifically, the backup power switch group for the second emergency busbar, through a dedicated link design between the transfer busbar and the second emergency busbar feeder switch BNT.A3 and the second emergency busbar backup emergency incoming switch BNB.A3, clearly defines the power transmission path from the backup emergency diesel generator to the second emergency busbar BNB, ensuring that when the second emergency diesel generator fails and becomes unavailable, the backup diesel generator's power can be accurately connected to the target busbar. Combined with the switching operation logic, it can quickly replace the function of the second emergency diesel generator.

[0032] In one alternative implementation, such as Figure 1 As shown, the circuit also includes: a backup emergency diesel generator auxiliary power distribution busbar BNF, a common busbar feeder switch for the backup emergency diesel generator auxiliary power distribution busbar BFA.A1, and a normal incoming switch for the backup emergency diesel generator auxiliary power distribution busbar BNF.A1. The backup emergency diesel generator auxiliary power distribution busbar BNF is connected to the plant's common busbar sequentially through the normal incoming switch for the backup emergency diesel generator auxiliary power distribution busbar BNF.A1 and the common busbar feeder switch for the backup emergency diesel generator auxiliary power distribution busbar BFA.A1. The backup emergency diesel generator auxiliary power distribution busbar BNF is equipped with the auxiliary power distribution load of the backup emergency diesel generator.

[0033] Furthermore, such as Figure 1As shown, the circuit also includes: a feeder switch BNM.A1 from the backup emergency diesel generator working bus to the auxiliary power distribution bus, and an emergency incoming switch BNF.A2 from the backup emergency diesel generator auxiliary power distribution bus. The backup emergency diesel generator auxiliary power distribution bus BNF is connected to the backup emergency diesel generator working bus BNM in sequence via the backup emergency incoming switch BNF.A2 and the feeder switch BNM.A1 from the backup emergency diesel generator working bus to the auxiliary power distribution bus.

[0034] Specifically, the standby emergency diesel generator is equipped with two independent auxiliary power supply lines. One power supply line is taken from the plant's common busbar BFA and is used to supply power to the auxiliary system when the standby diesel generator is in cold standby mode. The other power supply line is taken from the standby diesel generator working busbar BNM and is used to supply power to the auxiliary system when the standby diesel generator replaces the first or second emergency diesel generator.

[0035] When the standby diesel generator is in standby mode, the feeder switch BFA.A1 of the common busbar for the auxiliary power distribution bus of the standby emergency diesel generator and the normal incoming switch BNF.A1 of the auxiliary power distribution bus of the standby emergency diesel generator remain closed. The stable power from the plant's common busbar BFA is transmitted to the auxiliary power distribution busbar BNF through this circuit, providing continuous power supply to the auxiliary load of the standby diesel generator. This ensures that the auxiliary equipment is always in a standby state ready to start at any time, without having to activate the standby diesel generator itself, effectively avoiding energy waste. At the same time, because BFA is the plant's common busbar, the power supply stability is strong, and the risk of the standby diesel generator failing due to power outage can be completely eliminated.

[0036] When the standby diesel generator receives a command to replace the faulty emergency diesel generator, the feeder switch BFA.A1 on the common busbar supplying the auxiliary power distribution bus of the standby emergency diesel generator and the normal incoming switch BNF.A1 on the auxiliary power distribution bus of the standby emergency diesel generator will simultaneously open and isolate. At the same time, the feeder switch BNM.A1 on the working busbar of the standby emergency diesel generator to the auxiliary power distribution bus and the emergency incoming switch BNF.A2 on the auxiliary power distribution bus of the standby emergency diesel generator will simultaneously close. After the standby diesel generator starts, its own qualified power output will first be connected to the working busbar BNM of the standby emergency diesel generator, and then distributed through this circuit to the auxiliary power distribution busbar BNF of the standby emergency diesel generator, providing continuous power to the auxiliary load. This design ensures that the auxiliary power supply of the standby diesel generator is from the same source as its own emergency power supply, completely eliminating dependence on the external common busbar, effectively avoiding the risk of auxiliary equipment failure due to external power failure during the replacement process, and ensuring that the standby diesel generator continuously and stably performs its emergency power supply function.

[0037] In one optional implementation, when the standby emergency diesel generator is in standby mode, the following switches are configured: First Emergency Busbar Standby Emergency Incoming Switch BNA.A3, Second Emergency Busbar Standby Emergency Incoming Switch BNB.A3, Transfer Busbar to First Emergency Busbar Feeder Switch BNT.A2, Transfer Busbar to Second Emergency Busbar Feeder Switch BNT.A3, Transfer Busbar Incoming Switch BNT.A1, Standby Emergency Diesel Generator to Transfer Busbar Connecting Switch BNM.A3, and Standby Emergency Diesel Generator Outgoing Switch BNM.A2. The backup emergency diesel generator working bus to auxiliary power distribution bus feeder switch BNM.A1 and the backup emergency diesel generator auxiliary power distribution bus emergency incoming switch BNF.A2 are both in the isolated open state. The backup emergency diesel generator auxiliary power distribution bus normal incoming switch BNF.A1 and the common bus to the backup emergency diesel generator auxiliary power distribution bus feeder switch BFA.A1 are in the closed state. The backup emergency diesel generator auxiliary power distribution bus BNF is energized, supplying power to the backup emergency diesel generator auxiliary power distribution load.

[0038] Specifically, by placing the first emergency bus backup incoming line switch BNA.A3, the second emergency bus backup incoming line switch BNB.A3, and all the associated switches (BNT.A2, BNT.A3, BNT.A1, BNM.A3) between the transfer bus and the emergency bus and working bus, the main circuit of the backup diesel generator is completely isolated from the original emergency power system of the nuclear power plant. This avoids conflicts or erroneous interference between the backup circuit and the power supply logic of the original emergency bus and emergency diesel generator when the backup circuit is idle, and ensures that the normal standby and operation of the original two emergency diesel generators are not affected. It is perfectly compatible with the existing system structure and requires no modification to the original core circuit.

[0039] In one optional implementation, when the standby emergency diesel generator undergoes periodic testing, the first emergency bus backup incoming switch BNA.A3, the second emergency bus backup emergency incoming switch BNB.A3, the feeder switch from the transfer bus to the first emergency bus BNT.A2, the feeder switch from the transfer bus to the second emergency bus BNT.A3, the transfer bus incoming switch BNT.A1, and the tie switch from the standby emergency diesel generator to the transfer bus BNM.A3 are all in the isolated open state. The feeder switch from the standby emergency diesel generator working bus to the auxiliary power distribution bus BNM.A1, the emergency incoming switch from the standby emergency diesel generator auxiliary power distribution bus BNF.A2, the normal incoming switch from the standby emergency diesel generator auxiliary power distribution bus BNF.A1, and the feeder switch from the common bus to the standby emergency diesel generator auxiliary power distribution bus BFA.A1 are in the closed state. When the standby emergency diesel generator starts and its output voltage and frequency reach preset values, the standby emergency diesel generator output switch BNM.A2... It is connected to the plant's common busbar BFA and loaded via synchronous closing.

[0040] Specifically, by placing the first emergency bus backup incoming switch BNA.A3, the second emergency bus backup incoming switch BNB.A3, the feeder switch from the transfer bus to the first emergency bus BNT.A2, the feeder switch from the transfer bus to the second emergency bus BNT.A3, the transfer bus incoming switch BNT.A1, and the tie switch from the backup emergency diesel generator to the transfer bus BNM.A3 into the isolated open state, complete physical isolation between the backup diesel generator test circuit and the nuclear power plant's original emergency power system is achieved. During the test, the startup and grid connection of the backup diesel generator will not interfere with the normal standby or operation of the original emergency system, avoiding risks such as emergency bus malfunctions and power conflicts caused by the test operation, and ensuring the stability and reliability of the original emergency power supply system.

[0041] In one optional implementation, when the first emergency diesel generator fails and becomes unavailable, the emergency incoming switch BNA.A2 of the first emergency bus, the feeder switch BFA.A1 of the public bus for the auxiliary power distribution bus of the standby emergency diesel generator, the normal incoming switch BNF.A1 of the auxiliary power distribution bus of the standby emergency diesel generator, the standby emergency incoming switch BNB.A3 of the second emergency bus, and the feeder switch BNT.A3 of the transfer bus to the second emergency bus are in the isolated open state; the standby emergency incoming switch BNA.A3 of the first emergency bus, the feeder switch BNT.A2 of the transfer bus to the first emergency bus, the incoming switch BNT.A1 of the transfer bus, the tie switch BNM.A3 of the standby emergency diesel generator to the transfer bus, the feeder switch BNM.A1 of the standby emergency diesel generator working bus to the auxiliary power distribution bus, and the emergency incoming switch BNF.A2 of the auxiliary power distribution bus of the standby emergency diesel generator are in the closed state; and the outgoing switch BNM.A2 of the standby emergency diesel generator is closed. Place it in the working position and close the circuit breaker according to the start signal.

[0042] Specifically, when the first emergency diesel generator fails and becomes unavailable, the switching operation is first performed to configure the opening and closing of the aforementioned switches, isolating the power transmission path from the backup emergency diesel generator to the second emergency bus BNB and opening the power transmission path from the backup emergency diesel generator to the first emergency bus BNA. The backup emergency diesel generator output switch BNM.A2 is placed in the working position, ready to close. When the backup emergency diesel generator receives the start signal from the first emergency diesel generator, it automatically starts and adjusts the output voltage and frequency. Once the voltage and frequency reach the qualified standards, the backup emergency diesel generator output switch BNM.A2 automatically closes, and the power from the backup emergency diesel generator is transmitted to the first emergency bus BNA via the main link. Simultaneously, the auxiliary equipment receives stable power from the backup emergency diesel generator working bus BNM, achieving seamless replacement of the first emergency diesel generator's function.

[0043] In one optional implementation, when the second emergency diesel generator fails and becomes unavailable, the emergency incoming switch BNB.A2 of the second emergency bus, the feeder switch BFA.A1 of the public bus for the auxiliary power distribution bus of the standby emergency diesel generator, the normal incoming switch BNF.A1 of the auxiliary power distribution bus of the standby emergency diesel generator, the standby emergency incoming switch BNA.A3 of the first emergency bus, and the feeder switch BNT.A2 of the transfer bus to the first emergency bus are in the isolated open state; the standby emergency incoming switch BNB.A3 of the second emergency bus, the feeder switch BNT.A3 of the transfer bus to the second emergency bus, the incoming switch BNT.A1 of the transfer bus, the tie switch BNM.A3 of the standby emergency diesel generator to the transfer bus, the feeder switch BNM.A1 of the standby emergency diesel generator working bus to the auxiliary power distribution bus, and the emergency incoming switch BNF.A2 of the auxiliary power distribution bus of the standby emergency diesel generator are in the closed state; and the output switch BNM.A2 of the standby emergency diesel generator is closed. Place it in the working position and close the circuit breaker according to the start signal.

[0044] Specifically, when the second emergency diesel generator fails and becomes unavailable, the switching operation is first performed to configure the opening and closing of the aforementioned switches, isolating the power transmission path from the standby emergency diesel generator to the first emergency bus BNA and opening the power transmission path from the standby emergency diesel generator to the second emergency bus BNB. The standby emergency diesel generator output switch BNM.A2 is placed in the working position, ready to close. When the standby emergency diesel generator receives the start signal from the first emergency diesel generator, it automatically starts and adjusts the output voltage and frequency. Once the voltage and frequency reach the qualified standards, the standby emergency diesel generator output switch BNM.A2 automatically closes, and the power from the standby emergency diesel generator is transmitted to the second emergency bus BNB via the main link. Simultaneously, the auxiliary equipment receives stable power from the standby emergency diesel generator working bus BNM, achieving seamless replacement of the first emergency diesel generator's function.

[0045] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A power supply circuit for a high temperature gas cooled reactor nuclear power plant back-up emergency diesel generator set, characterised in that, The circuit comprises: a standby emergency diesel generator, a standby emergency diesel generator operating bus, a standby emergency diesel generator transfer bus, a standby emergency diesel generator outlet switch, a standby power transfer switch group, a first emergency bus standby power switch group and a second emergency bus standby power switch group, wherein The standby emergency diesel generator is connected to the standby emergency diesel generator operating bus through the standby emergency diesel generator outlet switch, and the standby emergency diesel generator operating bus is connected to the standby emergency diesel generator transfer bus through the standby power transfer switch group. The standby emergency diesel generator transfer bus is connected to a first emergency bus through the first emergency bus standby power switch group, and the standby emergency diesel generator transfer bus is connected to a second emergency bus through the second emergency bus standby power switch group, a first emergency diesel generator is arranged on the first emergency bus, and a second emergency diesel generator is arranged on the second emergency bus.

2. The back-up emergency diesel generator supply circuit for a high temperature gas cooled reactor nuclear power plant according to claim 1, characterized in that, The standby power transfer switch group comprises: a standby emergency diesel generator to transfer bus liaison switch and a transfer bus incoming line switch, wherein One end of the standby emergency diesel generator to transfer bus liaison switch is connected to the standby emergency diesel generator operating bus, the other end of the standby emergency diesel generator to transfer bus liaison switch is connected to one end of the transfer bus incoming line switch, and the other end of the transfer bus incoming line switch is connected to the standby emergency diesel generator transfer bus.

3. The back-up emergency diesel generator supply circuit for a high temperature gas cooled reactor nuclear power plant of claim 2, characterized in that, The first emergency bus standby power switch group comprises: a transfer bus to first emergency bus feeder switch and a first emergency bus standby emergency incoming line switch, wherein One end of the transfer bus to first emergency bus feeder switch is connected to the standby emergency diesel generator transfer bus, the other end of the transfer bus to first emergency bus feeder switch is connected to one end of the first emergency bus standby emergency incoming line switch, and the other end of the first emergency bus standby emergency incoming line switch is connected to the first emergency bus.

4. A back-up emergency diesel generator supply circuit for a high temperature gas cooled nuclear power plant according to claim 3, characterized in that, The second emergency bus standby power switch group comprises: a transfer bus to second emergency bus feeder switch and a second emergency bus standby emergency incoming line switch, wherein One end of the transfer bus to second emergency bus feeder switch is connected to the standby emergency diesel generator transfer bus, the other end of the transfer bus to second emergency bus feeder switch is connected to one end of the second emergency bus standby emergency incoming line switch, and the other end of the second emergency bus standby emergency incoming line switch is connected to the second emergency bus.

5. A back-up emergency diesel generator supply circuit for a high temperature gas cooled nuclear power plant according to claim 4, characterized in that, The circuit further comprises: a standby emergency diesel generator auxiliary power distribution bus, a public bus standby emergency diesel generator auxiliary power distribution bus feeder switch and a standby emergency diesel generator auxiliary power distribution bus normal incoming line switch, wherein The standby emergency diesel generator auxiliary power distribution bus is connected to the plant public bus through the standby emergency diesel generator auxiliary power distribution bus normal incoming line switch and the public bus standby emergency diesel generator auxiliary power distribution bus feeder switch in sequence, and the standby emergency diesel generator auxiliary power distribution bus is provided with auxiliary power distribution loads of the standby emergency diesel generator.

6. A back-up emergency diesel generator supply circuit for a high temperature gas cooled nuclear power plant according to claim 5, characterized in that, The circuit further comprises a standby emergency diesel generator working bus to auxiliary power distribution bus feeder switch and a standby emergency diesel generator auxiliary power distribution bus emergency incoming line switch, wherein, The standby emergency diesel generator auxiliary power distribution bus is connected to the standby emergency diesel generator working bus through the standby emergency diesel generator auxiliary power distribution bus emergency incoming line switch and the standby emergency diesel generator working bus to auxiliary power distribution bus feeder switch in sequence.

7. A back-up emergency diesel generator supply circuit for a high temperature gas cooled nuclear power plant according to claim 6, characterized in that, When the standby emergency diesel generator is in a standby state, the first emergency bus standby emergency incoming line switch, the second emergency bus standby emergency incoming line switch, the transfer bus to first emergency bus feeder switch, the transfer bus to second emergency bus feeder switch, the transfer bus incoming line switch, the standby emergency diesel generator to transfer bus tie switch, the standby emergency diesel generator outlet switch, the standby emergency diesel generator working bus to auxiliary power distribution bus feeder switch and the standby emergency diesel generator auxiliary power distribution bus emergency incoming line switch are in an isolated and tripped state, the standby emergency diesel generator auxiliary power distribution bus normal incoming line switch and the public bus standby emergency diesel generator auxiliary power distribution bus feeder switch are in a closed state, and the standby emergency diesel generator auxiliary power distribution bus is electrified to supply power to the auxiliary power distribution loads of the standby emergency diesel generator.

8. A back-up emergency diesel generator supply circuit for a high temperature gas cooled nuclear power plant according to claim 7, characterized in that, When the standby emergency diesel generator carries out a periodic test, the first emergency bus standby incoming line switch, the second emergency bus standby emergency incoming line switch, the transfer bus to first emergency bus feeder switch, the transfer bus to second emergency bus feeder switch and the transfer bus incoming line switch are in an isolated and tripped state, the standby emergency diesel generator working bus to auxiliary power distribution bus feeder switch, the standby emergency diesel generator auxiliary power distribution bus emergency incoming line switch, the standby emergency diesel generator auxiliary power distribution bus normal incoming line switch and the public bus standby emergency diesel generator auxiliary power distribution bus feeder switch are in a closed state, and when the standby emergency diesel generator is started and the outlet voltage and frequency reach preset values, the standby emergency diesel generator outlet switch is connected to the plant public bus in parallel through a synchronizing closing mode.

9. A back-up emergency diesel generator supply circuit for a high temperature gas cooled nuclear power plant according to claim 7, characterized in that, When the first emergency diesel generator fails to be available, the emergency incoming line switch of the first emergency bus, the feeder switch of the standby emergency diesel generator auxiliary power distribution bus provided by the public bus, the normal incoming line switch of the standby emergency diesel generator auxiliary power distribution bus, the standby emergency incoming line switch of the second emergency bus, the feeder switch of the second emergency bus to the second emergency bus, and the feeder switch of the second emergency bus to the second emergency bus are in the isolated open state, the standby emergency incoming line switch of the first emergency bus, the feeder switch of the second emergency bus to the first emergency bus, the feeder switch of the second emergency bus to the first emergency bus, the feeder switch of the second emergency bus to the first emergency bus, the feeder switch of the second emergency bus to the first emergency bus, and the feeder switch of the second emergency bus to the first emergency bus are in the closed state, and the feeder switch of the second emergency bus to the first emergency bus is in the closed state. The outgoing switch of the standby emergency diesel generator is placed in the working position and closed according to the starting signal.

10. The back-up emergency diesel generator power supply circuit for a high temperature gas cooled reactor nuclear power plant of claim 7, characterized in that, When the second emergency diesel generator fails to be available, the emergency incoming line switch of the second emergency bus, the feeder switch of the standby emergency diesel generator auxiliary power distribution bus provided by the public bus, the normal incoming line switch of the standby emergency diesel generator auxiliary power distribution bus, the standby emergency incoming line switch of the first emergency bus, the feeder switch of the second emergency bus to the first emergency bus, and the feeder switch of the second emergency bus to the first emergency bus are in the isolated open state, the standby emergency incoming line switch of the second emergency bus, the feeder switch of the second emergency bus to the second emergency bus, the feeder switch of the second emergency bus to the second emergency bus, the feeder switch of the second emergency bus to the second emergency bus, the feeder switch of the second emergency bus to the second emergency bus, and the feeder switch of the second emergency bus to the second emergency bus are in the closed state, and the feeder switch of the second emergency bus to the second emergency bus is in the closed state. The outgoing switch of the standby emergency diesel generator is placed in the working position and closed according to the starting signal.

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