Nuclear power plant emergency power supply control method and system

Abstract

The invention relates to the technical field of nuclear power, in particular to a nuclear power plant emergency power supply control method and system, and the method comprises the steps: enabling an energy storage system to be connected to an emergency bus under the condition that an external power supply of a nuclear power unit breaks down, and starting a diesel generator under the condition that the charge state of the energy storage system meets a preset condition; or, under the condition that the external power supply of the nuclear power unit breaks down, a diesel generator is started, and under the condition that the diesel generator breaks down, the energy storage system is connected to an emergency bus so as to supply power to the nuclear power unit. The system can provide a power supply for a nuclear power unit in time, reduces the complexity of an emergency power supply system, and improves the operation reliability of a nuclear power plant at a lower cost.

Description

Technical Field

[0001] The present invention relates to the field of nuclear power technology, and in particular to a nuclear power plant emergency power supply control method and system in the field of nuclear power technology. Background Art

[0002] In recent years, my country's pressurized water reactor nuclear power plants have all used diesel generator sets as emergency power sources for medium-voltage plant electricity, ensuring plant safety in the event of a complete loss of external power. However, with advances in nuclear power technology, the redundant configuration of homogeneous diesel generators may not effectively mitigate the risk of single failures in response to common-cause failures. The benefits of redundant diesel generators for nuclear power plant operation have diminished, significantly increasing the construction and maintenance costs of emergency power systems. Furthermore, frequent start-up and shutdown testing during routine maintenance accelerates the aging and wear of diesel generator sets, while high power demands and the requirement for rapid startup further complicate the design and operation of emergency power systems. Summary of the Invention

[0003] The purpose of the present invention is to provide a method and system for controlling emergency power supply of a nuclear power plant. The technical solutions adopted are as follows: In a first aspect, an embodiment of the present invention provides a nuclear power plant emergency power supply control system, the system comprising: In the event of a failure in the external power supply of the nuclear power unit, the energy storage system is connected to the emergency bus, and when it is detected that the charge state of the energy storage system meets the preset conditions, the diesel generator is started; Alternatively, in the event that the external power supply of the nuclear power unit fails, the diesel generator is started, and in the event that the diesel generator fails, the energy storage system is connected to the emergency bus to provide power to the nuclear power unit.

[0004] In a second aspect, an embodiment of the present invention provides a method for controlling an emergency power supply of a nuclear power plant, the method comprising: An energy storage system is used to connect to the emergency bus in the event of a failure of the external power supply of the nuclear power unit; or to connect the energy storage system to the emergency bus in the event of a failure of the diesel generator; A diesel generator is used to enter a startup state and connect to the emergency bus when the charge state of the energy storage system meets preset conditions; or to enter a startup state and connect to the emergency bus to provide power to the nuclear power unit when the external power supply of the nuclear power unit fails.

[0005] In a third aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the method in the first aspect or any one of the possible implementations of the first aspect.

[0006] In a fourth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the method in the first aspect or any possible implementation method described in the first aspect.

[0007] The present invention has the following beneficial effects: in a nuclear power plant emergency power supply control system, an energy storage system is used to replace the emergency power supply in a nuclear power unit or as a backup for an emergency diesel engine. In the event of a failure in the external power supply of the nuclear power unit, the energy storage system is preferentially connected to the emergency busbar. When it is detected that the charge state of the energy storage system meets a preset condition, the diesel generator is started. Alternatively, the energy storage system is used to replace the backup diesel engine in a nuclear power unit or as a backup for the backup diesel engine. In the event of a failure in the external power supply of the nuclear power unit, the diesel generator is started. In the event of a failure in the diesel generator, the energy storage system is connected to the emergency busbar to provide power to the nuclear power unit. In this way, power can be provided to the nuclear power unit in a timely manner, the complexity of the design and operation of the emergency power supply system can be reduced, and the operational reliability of the nuclear power plant can be improved at a lower construction and maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0009] Figure 1 This is a structural block diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 2 This is another structural block diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 3 This is a schematic diagram of an implementation flow of a nuclear power plant emergency power supply control method provided by an embodiment of the present invention; Figure 4 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 5This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 6 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 7 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 8 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 9 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 10 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 11 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 12 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 13 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 14 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 15 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 16 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 17 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 18 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 19 This is another implementation flow diagram of a nuclear power plant emergency power supply control method provided by an embodiment of the present invention; Figure 20 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 21 This is another structural diagram of a nuclear power plant emergency power supply control system provided by an embodiment of the present invention; Figure 22 This is another implementation flow diagram of a nuclear power plant emergency power supply control method provided by an embodiment of the present invention; Figure 23 It is a structural diagram of a computer device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0010] To further illustrate the technical means and effectiveness of the present invention in achieving its intended objectives, the following, in conjunction with the accompanying drawings and preferred embodiments, describes in detail the specific implementation, structure, features, and effectiveness of a nuclear power plant emergency power supply control method proposed in accordance with the present invention. In the following description, references to different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0011] In the description of the embodiments of the present invention, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present invention, "multiple" refers to two or more than two.

[0012] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0013] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0014] In some embodiments, the energy management system of a nuclear power plant is Figure 1 As mentioned above, the energy management system 11 controls the connection or disconnection between the energy storage system and the station-use step-up transformer and the medium-voltage busbar of the nuclear power plant through an intelligent switching switch. Figure 1 The energy storage system includes electrochemical energy storage (lithium-ion batteries, sodium-sulfur batteries, flow batteries, hydrogen energy, etc.), mechanical energy storage (pumped hydro, compressed air storage, flywheel storage, gravity storage, etc.), thermal energy storage (sensible heat storage, phase change storage, heat pump storage, and direct air thermal storage), and electromagnetic energy storage (superconducting magnetic energy storage, capacitor storage, and supercapacitor storage). The energy storage system automatically switches between the station-based step-up transformer and the nuclear power medium-voltage busbar via an intelligent transfer switch.

[0015] According to the type of nuclear power unit, it is divided into: active pressurized water reactor nuclear power unit (such as CPR1000) and passive pressurized water reactor nuclear power unit; among them: The CPR1000 nuclear power system 6.6 kilovolt (kV) medium voltage system can be divided into the following types: (1) Unit busbar (LGA / LGD / LGE): supplies power to the normal plant equipment of the nuclear energy system, that is, the related equipment that must be used when the unit is in normal operation (such as the electric main water supply system, etc.).

[0016] (2) Permanent busbar (LGB / LGC): supplies power to permanent plant equipment, i.e., electrical equipment that needs to be used during unit shutdown (such as air compressors, conventional island cooling water pumps, etc.).

[0017] (3) Common distribution busbar (9LGIA / 9LGIB): supplies power to the common auxiliary equipment of the two units, i.e., common plant equipment shared by the two units (e.g., equipment in the nuclear waste treatment plant).

[0018] (4) Emergency safety bus (LHA / LHB): supplies power to the emergency safety equipment of the nuclear energy system, i.e., the emergency safety equipment (such as the safety injection system, safety spray system, etc.) necessary to ensure that the reactor can be shut down normally and in a safe state when a unit fails; emergency safety equipment (such as the auxiliary water supply system, etc.) that will cause damage to the key facilities of the nuclear energy system if the power is lost.

[0019] In some possible implementations, the structure of a pressurized water reactor nuclear power plant (such as CPR1000) is as follows: Figure 2As shown, it includes a 500kV switchyard and a 220kV switchyard. Each 500kV switchyard is connected to the main transformer, which is in turn connected to two step-down transformers and, via a switch, to the generator of Unit 1. One step-down transformer is connected to the unit busbar (1LGE or 2LGE), while another step-down transformer is connected to each of the unit busbars (1LGA and 1LGD, or 2LGA and 2LGD). Unit busbar 1LGA is connected to permanent busbar 1LGB, which is connected to emergency safety busbar 1LHA and self-provided diesel generator 1LHP. Unit busbar 1LGD is connected to permanent busbar 1LGC, which is connected to emergency safety busbar 1LHB and self-provided diesel generator 1LHQ. The unit busbar 2LGA connects to the permanent busbar 2LGB, which in turn connects to the emergency busbar 2LHA and the self-provided diesel generator 2LHP. The unit busbar 2LGD connects to the permanent busbar 2LGC, which in turn connects to the emergency busbar 2LHB and the self-provided diesel generator 2LHQ. The 220kV switchyard is connected to the auxiliary transformer. Busbars 1LHA, 2LHA, 2LHA, and 2LHB connect to the emergency busbar 9LHT, which in turn connects to the standby diesel generator 0LHS.

[0020] If the 500kV line, the 220kV off-site grid, and the steam turbine generator set simultaneously fail, the nuclear power unit's own diesel generator (LHP / LHQ) must power the unit's emergency equipment to ensure an emergency shutdown of the reactor and maintain a safe and stable state. At this point, the 500kV switchyard's ultra-high voltage system circuit breaker and the 220kV switchyard's medium-voltage tie switch (LGB / LGC) both trip and open, depriving the medium-voltage unit switchboard and permanent switchboard of power.

[0021] The following is a detailed description of a method for controlling emergency power supply of a nuclear power plant provided by the present invention with reference to the accompanying drawings. Figure 3 , which shows a schematic diagram of an implementation flow of a nuclear power plant emergency power supply control method provided by one embodiment of the present invention, the method comprising: In the event of a failure in the external power supply of a nuclear power unit, emergency power supply to the nuclear power plant can be achieved by following the steps 301 and 302: 301 , connecting the energy storage system to the emergency bus, and starting the diesel generator when it is detected that the state of charge of the energy storage system meets a preset condition.

[0022] In this case, a failure in the nuclear power unit's external power supply refers to a simultaneous failure of the 500kV line, the 220kV external grid, and the steam turbine generator set. If these failures occur simultaneously, the LHP / LHQ (i.e., the nuclear power unit's own emergency diesel generator) is preferentially connected to the emergency busbar via the first switch to provide power. The operating status of the emergency diesel generator is also monitored. If the emergency diesel generator is operating normally, it remains connected to the emergency busbar. If the energy storage system's state of charge reaches a threshold, the system determines that the state of charge meets a preset condition.

[0023] Electrochemical energy storage systems come from a variety of sources, such as Figure 18 As shown, electrochemical energy storage can be obtained not only from nuclear power plants themselves, but also from clean energy sources such as wind power, photovoltaics and fuel cells, as well as other forms of energy connected to the grid (e.g. Figure 18 This diversified energy acquisition approach significantly enhances the reliability and resilience of the energy storage system as an emergency power source for nuclear power plants. In extreme disaster situations, it can effectively reduce the probability of failure of the original diesel engine system due to common cause failures.

[0024] In some possible implementations, step 101 may be implemented in the following two ways: Method 1: The energy storage system replaces the emergency power supply of the nuclear power unit. When the external power supply of the nuclear power unit fails, the energy storage system is connected to provide power; and when it is detected that the charge state of the energy storage system meets the preset conditions, the backup diesel generator is started to provide power to the nuclear power unit.

[0025] If a fault is detected in the emergency diesel generator, the emergency busbar is prioritized for connection to the energy storage system to provide power. Simultaneously, the energy storage system's state of charge (SOC) threshold is continuously checked. When the SOC falls below the set threshold, the system switches to the backup diesel generator or other emergency backup measures.

[0026] In other methods, the energy storage system replaces the backup diesel generator of the nuclear power unit, and when the external power supply of the nuclear power unit fails, the emergency diesel generator is started; and when the emergency diesel generator fails, the energy storage system is connected, and when it is detected that the charge state of the energy storage system meets the preset conditions, the preset emergency mode is started to provide power to the nuclear power unit.

[0027] Here, the preset emergency mode can be a customized emergency means. The energy storage system replaces the backup diesel generator of the nuclear power unit, and the implementation process of replacing the emergency power supply of the nuclear power unit with the energy storage system, such as Figure 20 and Figure 21 shown; in Figure 20 In this solution, the energy storage system replaces the original on-site backup diesel engine 0LHS, providing an emergency backup power source in the event of an accident on the 1LHA, 1LHB, 2LHA, or 2LHB emergency safety busbar. This solution can also integrate wind power, photovoltaic power, or fuel cells as energy storage systems to provide more sustainable, high-capacity energy.

[0028] exist Figure 21 In the case of an accident, the energy storage system replaces 1LHP and 2LHP to respond to the accident, while 0LHS is retained as a backup. In the event of an accident requiring a diesel engine response, the energy storage system, 1LHQ and 2LHQ are activated simultaneously.

[0029] Method 2: First, the energy storage system is used as a backup system for the emergency diesel generator. In the event of a failure in the external power supply of the nuclear power unit, the energy storage system is connected. Then, when it is detected that the charge state of the energy storage system meets the preset conditions, the emergency diesel generator is started. Finally, in the event of a failure in the emergency diesel generator, the backup diesel generator is started to provide power to the nuclear power unit.

[0030] For active pressurized water reactor nuclear power units, such as Figure 4 As shown in the figure, in the above accident conditions where both external power sources and the turbine generator are lost at the same time, priority is given to using LHP / LHQ (diesel generators provided by the nuclear power unit). When one of the diesel generators fails, the energy storage system is connected to the 9LHT busbar (i.e. Figure 4 The access scheme 1 shown in the figure is used to replace any failed diesel generator set, thereby improving the safety margin of the nuclear power plant's emergency power supply system. At the same time, the energy storage system (State of Charge) value is continuously checked. When the SOC falls below the set threshold, the backup diesel generator 0LHS or other backup emergency means are switched.

[0031] In some possible implementations, the energy storage system is divided into modules to obtain multiple energy storage modules; energy detection and real-time state of charge detection are performed on the multiple energy storage modules; and when it is detected that the energy of any energy storage module can maintain the emergency bus load working time less than a preset time, and the state of charge of any energy storage module meets the preset conditions, the backup diesel generator is connected to the public emergency bus to provide power.

[0032] Here, if the energy of any energy storage module among the multiple energy storage modules can maintain the emergency bus load working time shorter than the preset time, and if the charge state of any energy storage module is continuously monitored to meet the preset conditions, the public emergency bus is connected based on the switch to provide power. Figure 5 As shown in the figure, the overall capacity of the energy storage system is modularized to obtain multiple energy storage modules. When each energy storage module is connected to the nuclear energy system's medium-voltage emergency bus, a branch line connection method is adopted to ensure the relative independence and safety of different modules. Different branch lines are connected to different emergency bus sections, such as 1LHA, 1LHB, 2LHA or 2LHB (i.e. Figure 5 (See Access Option 2 for details.) In the event of a plant-wide power outage, priority is given to switching to the energy storage emergency incoming line to power downstream equipment. If a line anomaly occurs or the energy storage system's SOC approaches a minimum threshold, the emergency diesel engine system on the corresponding busbar is activated.

[0033] When the energy storage of the energy storage module corresponding to each emergency diesel engine system can only sustain the operation of the emergency bus load for less than 24 hours (i.e., the preset duration), the remaining SOC changes of the energy storage system should be continuously monitored after the accident occurs so as to switch to the emergency diesel engine system power supply mode in a timely manner.

[0034] In some possible implementations, a new emergency bus is added to the nuclear power unit; the energy storage system is used as a backup system for the emergency diesel generator. When the external power supply of the nuclear power unit fails, the energy storage system is connected to the new emergency bus to provide power.

[0035] Here, in Figure 4 On the basis of , an emergency bus LHE can be newly added. Figure 6 As shown in the figure, an emergency busbar LHE is added to the original standby emergency busbar 9LHT. The newly added emergency busbar LHE can also provide energy support for all medium-voltage emergency buses connected to it. In the event of a simultaneous loss of two external power sources and the turbine generator, the emergency busbar LHE is used first to connect to the energy storage system to supply power to the 1LHA, 1LHB, 2LHA, and 2LHB emergency safety buses (i.e. Figure 6 Access scheme 3 shown).

[0036] 302 , start the diesel generator. In the event of a failure of the diesel generator, connect the energy storage system to the emergency bus to provide power to the nuclear power unit.

[0037] Here, if a fault is detected in the emergency diesel generator, the state of charge of the energy storage system is continuously detected. When it is detected that the state of charge of the energy storage system is less than a preset threshold, it is determined that the state of charge meets the preset conditions, and the backup diesel generator is connected to the public emergency bus through a switch to provide power.

[0038] In some possible implementations, the energy storage system is used as a backup system for the backup diesel generator. When the external power supply of the nuclear power unit fails, the emergency diesel generator is started; then, when the emergency diesel generator fails, the energy storage system is connected; and when it is detected that the charge state of the energy storage system meets the preset conditions, the backup diesel generator is started to provide power to the nuclear power unit.

[0039] Here, the operating status of at least two emergency diesel generators is detected in real time; and when a fault is detected in the operating status of any emergency diesel generator, an abnormal signal of the operating status is obtained and transmitted to the control system, so that the control system triggers a switching mechanism to connect the energy storage system to the emergency bus.

[0040] In some embodiments, the energy storage system is used as a backup for the off-site emergency system to provide power to the nuclear power unit, such as Figure 7 As shown in the figure, the energy storage system uses the entire station as output and the 220kV switch station as the incoming line. As an off-site emergency system, when the original 500kV line and 220kV line fail, the energy storage system is connected to the 220kV switch station after inverter boosting, providing backup energy for the off-site power supply of the nuclear power plant (i.e. Figure 7 (See option 4 for connection.) Electrochemical energy storage systems are limited by current technology, and their use as off-site emergency systems remains under investigation. Mechanical energy storage, such as pumped hydro and gravity storage, is more suitable for this backup power solution.

[0041] In some embodiments, the nuclear power plant emergency power supply control system further comprises: a transformer and a unit generator; wherein the unit generator comprises: an active pressurized water reactor nuclear power unit generator and a passive pressurized water reactor nuclear power unit generator; Figure 2 As shown, the first end of the transformer is connected to the generator of the unit, and the second end is connected to the medium voltage bus; the transformer is used to transform the input power supply to obtain the power supply voltage for the operation of the generator of the unit.

[0042] In some possible implementations, Figure 8The passive pressurized water reactor nuclear power unit (such as the Hualong One) shown in the figure can be powered by the following process: Emergency loads, such as nuclear safety equipment and main equipment safety equipment, are connected to the emergency plant busbars (EMA and EMB). The EMA and EMB busbars have three power sources. Under normal operation, these buses are powered by the unit plant busbars ESA and ESD, respectively, and the standby plant busbars (ESB and ESC). If ESA and ESD lose power, the emergency plant busbar switches to the auxiliary transformer standby plant busbars ESB and ESC. If both of these power sources are lost, the corresponding emergency diesel generator sets independently power the nuclear safety equipment and main equipment safety equipment on the emergency plant busbars EMA and EMB.

[0043] In the event of a nuclear power plant losing both external power sources and the steam turbine generator simultaneously, the power supply must be switched from normal plant power to the emergency diesel generator (EMP / EMQ) started by the AC emergency power system through the power switching circuit. Circuit breaker 002JA is used to switch power, and the plant load is simultaneously swept and reloaded. If the emergency diesel generator is also unavailable, the backup diesel generator (EMS) is started and supplied via the backup power circuit breaker 003JA. This can be achieved through the following methods: Method 1: Figure 9 As shown in the figure, when a plant-wide power outage occurs, the system prioritizes the use of the EMP and EMQ as emergency power sources. During this period, the monitoring system monitors the operating status of the EMP and EMQ in real time. If one of the emergency diesel generators fails, the fault detection module quickly captures the abnormal signal and transmits it to the control system. The control system immediately triggers a switchover mechanism, prioritizing energy storage to connect to the EMT busbar to replace the failed generator set, effectively increasing the safety margin of the emergency power system. Simultaneously, the system continuously monitors the energy storage system's SOC threshold. Once the energy storage system's SOC falls below a pre-set threshold, the switchover mechanism immediately executes a power supply switchover operation, switching power to the backup diesel generator (EMS) or other backup emergency means. This ensures the continuity and reliability of the nuclear power plant's power supply and minimizes the impact of power outages on the plant's safe operation.

[0044] Method 2: If Figure 10 As shown, the overall capacity of the energy storage system is modularized. When connected to the nuclear power system's medium-voltage emergency busbar, separate lines are used to ensure relative independence and safety between different modules. Specifically, each branch line is connected to different emergency busbar sections of the EMA and / or EMB. In the event of a simultaneous loss of both external power sources and the turbine generator, the monitoring system captures the busbar power loss signal in real time, and the control system quickly triggers a fast-change switch, prioritizing the energy storage emergency line to power downstream equipment.

[0045] During the power supply process, the system continuously monitors the line status and the SOC value of the energy storage system. If an abnormality such as overcurrent or short circuit occurs in the line, or the SOC of the energy storage system approaches the minimum threshold, the monitoring system immediately issues a command: first disconnect the energy storage system from the bus, and at the same time activate the startup program of the emergency diesel engine system on the corresponding bus to ensure uninterrupted power supply. In particular, when the SOC of the energy storage module corresponding to each emergency diesel engine system can only maintain the emergency bus load for less than 24 hours, the changes in the remaining SOC of the energy storage are monitored in real time from the occurrence of the accident. Before the energy storage SOC drops to the preset switching threshold, the startup preparation work of the emergency diesel engine system is completed in advance, and the energy storage system is switched to the emergency diesel engine system in time to avoid emergency power supply interruption due to energy depletion of the energy storage system, thereby maximizing the reliability and stability of the nuclear energy system power supply.

[0046] Method three, such as Figure 11 As shown in the figure, compared to Option 1, this solution adds an emergency busbar (EME) to the existing backup emergency busbar (EMT). The newly added EME busbar can simultaneously provide energy support for all connected medium-voltage emergency buses (such as EMA and EMB). In the event of a plant-wide power outage, the EME busbar takes priority. By connecting to the energy storage system, it can also power the EMA and EMB medium-voltage emergency buses, creating a more flexible and reliable emergency power supply system.

[0047] In some possible implementations, the energy storage system can also replace the backup diesel generator EMS, such as Figure 12 As shown, the energy storage system replaces the original on-site backup diesel engine EMS and serves as a backup power source when the EMP and / or EMQ fail. It can also be connected to wind power, photovoltaic power, or fuel cells to provide continuous power.

[0048] In some possible implementations, the energy storage system can also replace the emergency diesel generator EMP; Figure 13 As shown in the figure, the energy storage system replaces the EMP to respond to accident conditions, while retaining the EMS as a backup power source. In the event of a fault requiring a diesel engine response, the energy storage system and EMS are activated simultaneously.

[0049] In some embodiments, Figure 14The passive pressurized water reactor nuclear power plant shown (such as the AP1000 / CAP1000 / CAP1400) can be powered using the following process: The site standby power system (ZOS) is powered by two 4,500 kW standby diesel generators, providing power to specific loads in the event of a loss of normal power and priority power. If the generators / priority or standby power are restored, the loads are manually transferred to the restored power source. Certain loads with special defense-in-depth capabilities (permanent non-safety loads) are considered priority loads and assigned to buses ES1 and ES2. These permanent non-safety loads are divided into two groups, so the loss of one group does not result in a complete system loss. Each group is connected to its own bus, ES1 and ES2, with each bus section backed up by a non-1E standby diesel generator set.

[0050] Two non-safety-class auxiliary diesel generators (35 kilowatts (kW), 380 volts (V)) are located in the auxiliary building. When other power sources are unavailable, these two generators provide power for Class 1E accident monitoring facilities, main control room lighting, instruments on channels B and C in the main control room, main control room ventilation, and equipment related to the PCCWST (passive containment cooling water storage tank) and the spent fuel pool. Within 72 hours (h) of the nuclear power plant losing all AC power, the auxiliary diesel generators do not need to supply power to the PCCWST, spent fuel pool, accident monitoring system, and lighting system. This can be achieved through the following methods: Method 1: If Figure 15 As shown in Figure 1, this solution adds an emergency busbar (ESM). The newly added ESM busbar can simultaneously serve all connected medium-voltage emergency buses. In the event of a plant-wide power outage, the system prioritizes backup diesel generators A and B to supply specific loads. During this period, the monitoring system monitors the operating status of backup diesel generators A and B in real time. If one of the backup diesel generators fails, the fault detection module quickly captures the abnormal signal and transmits it to the control system. The control system immediately triggers a switchover mechanism, prioritizing energy storage to connect to the emergency energy storage line to replace the failed generator set, effectively increasing the safety margin of the emergency power supply system. Simultaneously, the system continuously monitors the energy storage system's SOC threshold. Once the energy storage system SOC falls below a pre-set threshold, the switchover mechanism immediately switches power to the backup diesel generators (EMS) or other backup emergency means, ensuring the continuity and reliability of the nuclear power plant's power supply and minimizing the impact of power outages on safe operation.

[0051] Method 2: If Figure 16As shown, the overall capacity of the energy storage system is modularized. When connected to the nuclear power system's medium-voltage emergency busbar, separate lines are used to ensure relative independence and safety between different modules. Specifically, each branch line is connected to different emergency busbar sections of ES1 and ES2. In the event of a simultaneous loss of both external power sources and the turbine generator, the monitoring system captures the busbar power loss signal in real time, and the control system quickly triggers a fast-change switch, prioritizing the energy storage emergency line to power downstream equipment.

[0052] During the power supply process, the system continuously monitors the line status and the SOC value of the energy storage system. If an abnormality such as overcurrent or short circuit occurs in the line, or the SOC of the energy storage system approaches the minimum threshold, the monitoring system immediately issues a command: first disconnect the energy storage system from the bus, and at the same time activate the startup program of the emergency diesel engine system on the corresponding bus to ensure uninterrupted power supply. In particular, when the SOC of the energy storage module corresponding to each emergency diesel engine system can only maintain the emergency bus load for less than 24 hours, the system monitors the changes in the remaining SOC of the energy storage in real time from the moment the accident occurs. Before the energy storage SOC drops to the preset switching threshold, the startup preparation of the emergency diesel engine system is completed in advance, and the system is switched to the emergency diesel engine system in time to avoid emergency power supply interruption due to exhaustion of the SOC of the energy storage system, thereby maximizing the reliability and stability of the nuclear energy system power supply.

[0053] Method 3: If Figure 17 As shown, the energy storage system is used to replace the backup diesel generator A. When a fault occurs that requires the diesel engine to respond, the energy storage system and the backup diesel generator B are enabled at the same time.

[0054] The embodiment of the present invention provides a method for controlling emergency power supply of a nuclear power plant, such as Figure 19 As shown, combined Figure 19 The steps shown are explained below: 1901. Based on the operating status of the nuclear power plant, predict whether the energy of the energy storage system reaches a remaining energy threshold after a preset period of time.

[0055] Here, after an accident occurs in which both external power sources and the turbine generator are lost, the energy storage system is the first to start and respond, providing emergency power to the nuclear power plant while also checking the normal status of the emergency and backup diesel engines.

[0056] When the energy storage system provides support, it is predicted that the energy storage system will be close to the remaining capacity threshold after t hours (to prepare for diesel engine startup and line switching): if so, the diesel engine system will be set to hot standby state, and then further judge whether the current remaining energy of the energy storage system is close to the threshold: if so, the diesel engine switch will be prepared to prepare for switching to diesel engine power supply. Figure 4 As shown, the emergency diesel generator is connected to the emergency bus of the nuclear power unit through the first switch.

[0057] In some possible implementations, the above steps may be implemented through the following process: First, based on the operating status of the nuclear power plant, predict whether the energy of the energy storage system reaches a remaining energy threshold after a preset time period; Secondly, if the state of charge of the energy storage system reaches the remaining capacity threshold after a preset period of time, the emergency diesel generator is set to a hot standby state, and it is determined whether the current state of charge of the energy storage system reaches the remaining energy threshold; Thirdly, if the current state of charge of the energy storage system reaches the remaining energy threshold, the emergency diesel generator is connected to the emergency bus through a switch, and the switch between the energy storage system and the emergency bus is disconnected; Finally, if the current state of charge of the energy storage system reaches the remaining energy threshold, the emergency diesel generator is connected to the emergency bus through a switch, and the switch between the energy storage system and the emergency bus is disconnected.

[0058] In some possible implementations, this can be achieved by Figure 22 The steps shown implement the control process of the emergency power supply of the nuclear power plant: 2201, the external power grid and the steam turbine generator set failed simultaneously, causing the reactor to shut down.

[0059] 2202, the energy storage system responds first.

[0060] Here, after an accident occurs in which both external power sources and the turbine generator are lost, the energy storage system is the first to start and respond, providing emergency power to the nuclear power plant while also checking the normal status of the emergency and backup diesel engines.

[0061] 2203, determine whether the current energy storage system is close to the threshold in t hours.

[0062] Here, if the current energy storage system has t hours left to approach the threshold, proceed to step 2204; otherwise, return to step 2203.

[0063] When the energy storage system provides support, it is predicted that the energy storage system will approach the remaining capacity threshold after t hours (to prepare for diesel engine startup and line switching).

[0064] If so, the diesel engine system is set to hot standby mode. The system then determines whether the remaining energy in the energy storage system is close to the threshold. If so, the diesel engine switch is prepared to switch to diesel power. If not, the system proceeds to determine whether the emergency diesel engine is operating normally.

[0065] If not (i.e., the remaining SOC of the energy storage system will not approach the threshold within t hours), the energy storage system will maintain power supply.

[0066] 2204, set the diesel engine system to hot standby state.

[0067] 2205, determine whether the current remaining energy of the energy storage system is close to the threshold.

[0068] Here, if the remaining energy is close to the threshold, proceed to step 2206; otherwise, return to step 2205.

[0069] 2206, control the diesel generator to prepare for switching.

[0070] 2207, determine whether the emergency diesel generator is in normal condition.

[0071] If the emergency diesel engine is not functioning properly, the system will further check whether the backup diesel engine is functioning properly, proceeding to step 2208. If the backup diesel engine is also not functioning properly, the mobile emergency system will be activated to ensure emergency power supply. If the backup diesel engine is functioning properly, the system will return to the diesel engine system hot standby process (e.g., starting the backup diesel engine). If the emergency diesel engine is functioning properly, the system will follow the emergency diesel engine power supply process (with the normal emergency diesel engine being prioritized), returning to step 2206 to control the emergency diesel generator to prepare for power on and off.

[0072] 2208, determine whether the status of the standby diesel generator is normal.

[0073] Here, if the standby diesel generator is in normal state, the process returns to step 2206 to control the standby diesel generator to prepare for switching. If the standby diesel generator is in abnormal state, the process proceeds to step 2209 to start the mobile emergency system.

[0074] Step 2209, start the emergency system.

[0075] 1902. If the state of charge of the energy storage system reaches the remaining capacity threshold after a preset period of time, the emergency diesel generator is set to a hot standby state, and it is determined whether the current state of charge of the energy storage system reaches the remaining energy threshold.

[0076] 1903. If the current state of charge of the energy storage system reaches the remaining energy threshold, the emergency diesel generator is connected to the emergency bus, and the connection between the energy storage system and the emergency bus is disconnected.

[0077] 1904. If the emergency diesel generator fails, detect whether the backup diesel generator fails.

[0078] Here, the operating status of each of the at least two emergency diesel generators is detected in real time; if a fault is detected in the operating status of any emergency diesel generator, an abnormal signal of the operating status is obtained and transmitted to the control system, so that the control system triggers a switching mechanism to connect the emergency busbar to the energy storage system through a switch. Figure 4 As shown, the emergency bus (9LHT bus) is connected to the energy storage system.

[0079] 1905. If the standby diesel generator operates normally and the state of charge of the energy storage system meets the preset conditions, the standby diesel generator is connected to the public emergency bus.

[0080] Here, as Figure 4 As shown, in the event of a simultaneous loss of both external power sources and the steam turbine generator, the emergency diesel generator takes priority. If one of the diesel generators fails, the energy storage system is connected to the emergency bus (9LHT bus) to take over for the failed diesel generator set, thereby improving the safety margin of the nuclear power plant's emergency power supply system. Simultaneously, the energy storage system's SOC threshold is continuously monitored. When the SOC falls below the set threshold, a switch is activated to switch to the backup diesel generator (0LHS) or other backup emergency measures.

[0081] In some possible implementations, the energy storage system is divided into modules to obtain multiple energy storage modules; then, energy detection and real-time state of charge detection are performed on the multiple energy storage modules; and when it is detected that the energy of any energy storage module can maintain the emergency bus load working time less than the preset time, and the state of charge of any energy storage module meets the preset conditions, the backup diesel generator is connected to the public emergency bus to provide power. Figure 5 As shown, the overall capacity of the energy storage system is modularized and connected to different emergency bus sections using a branch line access method, such as 1LHA, 1LHB, 2LHA or 2LHB.

[0082] An embodiment of the present invention provides a nuclear power plant emergency power supply control system, the system comprising: An energy storage system is used to connect to the emergency bus in the event of a failure of the external power supply of the nuclear power unit; or to connect the energy storage system to the emergency bus in the event of a failure of the diesel generator; A diesel generator is used to enter a startup state and connect to the emergency bus when the charge state of the energy storage system meets preset conditions; or to enter a startup state and connect to the emergency bus to provide power to the nuclear power unit when the external power supply of the nuclear power unit fails.

[0083] In some possible implementations, the energy storage system is also used to replace the emergency power supply of the nuclear power unit with the energy storage system. In the event of a failure in the external power supply of the nuclear power unit, the energy storage system is connected to provide power. The diesel generator is also used to start the backup diesel generator to provide power to the nuclear power unit when it is detected that the charge state of the energy storage system meets preset conditions.

[0084] In some possible implementations, the energy storage system is also used to use the energy storage system as a backup system for the emergency diesel generator, and to connect to the energy storage system in the event of a failure in the external power supply of the nuclear power unit; the diesel generator is also used to start the emergency diesel generator when it is detected that the charge state of the energy storage system meets preset conditions; and to start the backup diesel generator in the event of a failure in the emergency diesel generator to provide power to the nuclear power unit.

[0085] In some possible implementations, the energy storage system is also used to add a new emergency bus in the nuclear power unit; the energy storage system is used as a backup system for the emergency diesel generator, and in the event of a failure in the external power supply of the nuclear power unit, the energy storage system is connected to the new emergency bus to provide power.

[0086] In some possible implementations, the diesel generator is also used to replace the backup diesel generator of the nuclear power unit with the energy storage system, and to start the emergency diesel generator in the event of a failure in the external power supply of the nuclear power unit; in the event of a failure in the emergency diesel generator, the energy storage system is connected, and when it is detected that the charge state of the energy storage system meets the preset conditions, the preset emergency mode is started to provide power to the nuclear power unit.

[0087] In some possible implementations, the diesel generator is also used to use the energy storage system as a backup system for the backup diesel generator. In the event that the external power supply of the nuclear power unit fails, the emergency diesel generator is started; in the event that the emergency diesel generator fails, the energy storage system is connected; and when it is detected that the charge state of the energy storage system meets the preset conditions, the backup diesel generator is started to provide power to the nuclear power unit.

[0088] In some possible implementations, the diesel generator is also used to perform real-time detection of the operating status of at least two emergency diesel generators; when a fault is detected in the operating status of any emergency diesel generator, an abnormal signal of the operating status is obtained and transmitted to the control system, so that the control system triggers a switching mechanism to connect the energy storage system to the emergency bus.

[0089] In some possible implementations, the energy storage system is further used to divide the energy storage system into modules to obtain multiple energy storage modules; perform energy detection and real-time state of charge detection on the multiple energy storage modules; and the diesel generator is further used to connect the backup diesel generator to the public emergency bus to provide power when it is detected that the energy of any energy storage module can maintain the emergency bus load working time less than a preset time and the state of charge of any energy storage module meets the preset conditions.

[0090] In some possible implementations, the nuclear power plant emergency power supply control system is also used to predict, based on the operating status of the nuclear power plant, whether the energy of the energy storage system reaches a residual energy threshold after a preset period of time; if the charge state of the energy storage system reaches a residual capacity threshold after a preset period of time, the emergency diesel generator is set to a hot standby state, and it is determined whether the current charge state of the energy storage system reaches the residual energy threshold; if the current charge state of the energy storage system reaches the residual energy threshold, the emergency diesel generator is connected to the emergency bus and the connection between the energy storage system and the emergency bus is disconnected; if the emergency diesel generator fails, detect whether the standby diesel generator fails; if the standby diesel generator operates normally and the charge state of the energy storage system meets the preset conditions, the standby diesel generator is connected to the public emergency bus.

[0091] Optionally, the transmission medium may be a wired link (such as, but not limited to, coaxial cable, optical fiber, and digital subscriber line (DSL)) or a wireless link (such as, but not limited to, wireless Fidelity (WIFI), Bluetooth, and mobile device network). It should be noted that the system provided in the above embodiment is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the computer device can be divided into different functional modules to complete all or part of the functions described above. In addition, the method embodiments provided in the above embodiments belong to the same concept. The specific implementation process is detailed in the method embodiments and will not be repeated here.

[0092] Figure 23 FIG. 1 is a schematic diagram of the structure of a computer device provided by an embodiment of the present invention. For example, Figure 23 As shown, the computer device 2300 includes: a memory 2301, a processor 2302, and a computer program 2303 stored in the memory 2301 and running on the processor 2302, wherein when the processor 2302 executes the computer program 2303, the computer device can execute any one of the nuclear power plant emergency power supply control methods introduced above.

[0093] In addition, an embodiment of the present invention also protects a system, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to perform a nuclear power plant emergency power supply control method provided by an embodiment of the present invention. This embodiment can divide the system into functional modules according to the above method example. For example, it can correspond to each functional module, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0094] It should be understood that the system provided in this embodiment is used to execute the above-mentioned nuclear power plant emergency power supply control method, and thus can achieve the same effect as the above-mentioned implementation method. In the case of adopting an integrated unit, the system may include a processing module and a storage module. Specifically, when the system is applied to a device, the processing module can be used to control and manage the operation of the device. The storage module can be used to support the device in executing mutual program codes, etc. Specifically, the processing module can be a processor or a controller, which can implement or execute the various exemplary logical blocks, modules and circuits described in conjunction with the contents disclosed in the present invention. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module can be a memory.

[0095] In addition, the system provided by the embodiments of the present invention may be specifically a chip, component, or module. The chip may include a connected processor and memory; the memory is used to store instructions. When the processor calls and executes the instructions, the chip can execute the nuclear power plant emergency power supply control method provided in the above embodiment. This embodiment also provides a computer-readable storage medium, which stores computer program code. When the computer program code is executed on a computer, it causes the computer to execute the relevant method steps described above to implement the nuclear power plant emergency power supply control method provided in the above embodiment.

[0096] This embodiment also provides a computer program product, which, when running on a computer, enables the computer to execute the above-mentioned related steps to implement a nuclear power plant emergency power supply control method provided by the above embodiment. Among them, the system, computer-readable storage medium, computer program product or chip provided by this embodiment are all used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here. Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual application, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above.

[0097] In the embodiments provided by the present invention, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For example, the division of modules or units is merely a logical functional division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interface, indirect coupling or communication connection of systems or units, and can be electrical, mechanical or other forms.

[0098] It should be noted that the above-mentioned order of the embodiments of the present invention is for description only and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multi-task processing and parallel processing are also possible or may be advantageous. The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments. The above content is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be covered within the scope of protection of the present invention.

Claims

1. A nuclear power plant emergency power supply control method, characterized in that: The method comprises: In the event of a failure in the external power supply of the nuclear power unit, the energy storage system is connected to the emergency bus, and when it is detected that the charge state of the energy storage system meets the preset conditions, the diesel generator is started; Alternatively, in the event that the external power supply of the nuclear power unit fails, the diesel generator is started, and in the event that the diesel generator fails, the energy storage system is connected to the emergency bus to provide power to the nuclear power unit.

2. A nuclear power plant emergency power supply control method according to claim 1, characterized in that: The method of connecting the energy storage system to the emergency bus when the external power supply of the nuclear power unit fails and starting the diesel generator when it is detected that the charge state of the energy storage system meets a preset condition includes: The energy storage system is used to replace the emergency power supply of the nuclear power unit, and in the event of a failure of the external power supply of the nuclear power unit, the energy storage system is connected to provide power; When it is detected that the state of charge of the energy storage system meets a preset condition, the backup diesel generator is started to provide power to the nuclear power unit.

3. A nuclear power plant emergency power supply control method according to claim 1, characterized in that: The method of connecting the energy storage system to the emergency bus when the external power supply of the nuclear power unit fails and starting the diesel generator when it is detected that the charge state of the energy storage system meets a preset condition includes: Using the energy storage system as a backup system for the emergency diesel generator, and accessing the energy storage system in the event of a failure in the external power supply of the nuclear power unit; When it is detected that the state of charge of the energy storage system meets a preset condition, starting the emergency diesel generator; In the event of a failure of the emergency diesel generator, the backup diesel generator is started to provide power to the nuclear power unit.

4. A nuclear power plant emergency power supply control method according to claim 3, characterized in that: The energy storage system is used as a backup system for the emergency diesel generator, and the energy storage system is connected when the external power supply of the nuclear power unit fails, including: Adding a new emergency busbar to the nuclear power unit; The energy storage system is used as a backup system for the emergency diesel generator. When the external power supply of the nuclear power unit fails, the energy storage system is connected to the newly added emergency bus to provide power.

5. A nuclear power plant emergency power supply control method according to claim 1, characterized in that: When the external power supply of the nuclear power unit fails, the diesel generator is started, and when the diesel generator fails, the energy storage system is connected to the emergency bus to provide power to the nuclear power unit, including: Replacing the backup diesel generator of the nuclear power unit with an energy storage system to start the emergency diesel generator in the event of a failure in the external power supply of the nuclear power unit; In the event of a failure of the emergency diesel generator, the energy storage system is connected, and when it is detected that the charge state of the energy storage system meets a preset condition, a preset emergency mode is activated to provide power to the nuclear power unit.

6. A nuclear power plant emergency power supply control method according to claim 1, characterized in that: When the external power supply of the nuclear power unit fails, the diesel generator is started, and when the diesel generator fails, the energy storage system is connected to the emergency bus to provide power to the nuclear power unit, including: The energy storage system is used as a backup system for the backup diesel generator, and the emergency diesel generator is started in the event of a failure of the external power supply of the nuclear power unit; In the event of a failure of the emergency diesel generator, access to the energy storage system; When it is detected that the state of charge of the energy storage system meets a preset condition, the backup diesel generator is started to provide power to the nuclear power unit.

7. A nuclear power plant emergency power supply control method according to claim 6, characterized in that: In the event of a failure of the emergency diesel generator, accessing the energy storage system includes: Conduct real-time monitoring of the operating status of at least two emergency diesel generators; When a fault is detected in the operating state of any emergency diesel generator, an abnormal signal of the operating state is obtained and transmitted to the control system, so that the control system triggers a switching mechanism to connect the energy storage system to the emergency bus.

8. A nuclear power plant emergency power supply control method according to claim 1, characterized in that: The method further comprises: Dividing the energy storage system into modules to obtain a plurality of energy storage modules; Performing energy detection and real-time state of charge detection on the multiple energy storage modules; When it is detected that the energy of any energy storage module can maintain the emergency bus load working time less than the preset time, and the charge state of any energy storage module meets the preset conditions, the backup diesel generator is connected to the public emergency bus to provide power.

9. A nuclear power plant emergency power supply control method according to claim 1, characterized in that: The method further comprises: Based on the operating status of the nuclear power plant, predict whether the energy of the energy storage system reaches a remaining energy threshold after a preset period of time; If the state of charge of the energy storage system reaches the remaining capacity threshold after a preset time, the emergency diesel generator is set to a hot standby state, and it is determined whether the current state of charge of the energy storage system reaches the remaining energy threshold; If the current state of charge of the energy storage system reaches the remaining energy threshold, the emergency diesel generator is connected to the emergency bus, and the connection between the energy storage system and the emergency bus is disconnected; If the emergency diesel generator fails, detecting whether the standby diesel generator fails; If the standby diesel generator operates normally and the state of charge of the energy storage system meets the preset conditions, the standby diesel generator is connected to the public emergency bus.

10. A nuclear power plant emergency power supply control system, characterized in that: The system comprises: An energy storage system is used to connect to the emergency bus in the event of a failure of the external power supply of the nuclear power unit; or to connect the energy storage system to the emergency bus in the event of a failure of the diesel generator; A diesel generator is used to enter a startup state and connect to the emergency bus when the charge state of the energy storage system meets preset conditions; or to enter a startup state and connect to the emergency bus to provide power to the nuclear power unit when the external power supply of the nuclear power unit fails.

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