Frequency modulation and emergency power supply control method and system for nuclear power plant

Abstract

The invention relates to a nuclear power plant frequency modulation and emergency power supply control method and system, and the method is used for a super capacitor energy storage system, and comprises the steps: obtaining the real-time operation information of a generator; the real-time operation information comprises output frequency; determining whether the generator operates normally according to the real-time operation information, if so, entering a first mode, and if not, entering a second mode; in the first mode, the super-capacitor energy storage system is controlled to be connected with an output bus of the generator, and the super-capacitor energy storage system is controlled to be charged or discharged according to the output frequency, so that the output frequency is stabilized in a set frequency range; and in the second mode, the super-capacitor energy storage system is controlled to be connected with the emergency bus, and the super-capacitor energy storage system is controlled to supply power to the emergency bus before the emergency power supply system is started. The frequency modulation response speed of the generator can be remarkably improved, the frequency modulation duration is shortened, and the switching-in success rate of an emergency power supply system can be improved when emergency power supply is needed.

Description

Technical Field

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

[0002] When nuclear power units participate in grid frequency regulation, due to their physical characteristics (such as over-power limit, slow response speed of reactor control rods, etc.), they often have problems such as slow response speed and insufficient response time when responding to grid frequency regulation instructions.

[0003] On the other hand, the emergency power supply systems of nuclear power plants (mainly including diesel generators, battery packs and external power supplies) currently have certain reliability issues. For example, the diesel generators take a long time to start up and there is a risk of startup failure. As a result, under extreme weather conditions or maintenance conditions, some necessary equipment for maintaining the safe operation of the nuclear power plant may lose both external and internal power supplies, affecting the safe operation of the nuclear power plant. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for controlling frequency regulation and emergency power supply of a nuclear power plant.

[0005] The technical solution adopted by the present invention to solve the technical problem is to construct a nuclear power plant frequency modulation and emergency power supply control method for a supercapacitor energy storage system, wherein the supercapacitor energy storage system includes multiple supercapacitors. The method comprises:

[0006] Acquiring real-time operating information of the generator; the real-time operating information includes output frequency;

[0007] Determine whether the generator is operating normally according to the real-time operating information, and if so, enter the first mode, otherwise enter the second mode;

[0008] In the first mode, the supercapacitor energy storage system is controlled to be connected to the output bus of the generator, and the supercapacitor energy storage system is controlled to charge or discharge according to the output frequency, so that the output frequency is stabilized within a set frequency range;

[0009] In the second mode, the supercapacitor energy storage system is controlled to be connected to the emergency bus, and before the emergency power supply system is started, the supercapacitor energy storage system is controlled to supply power to the emergency bus.

[0010] Preferably, controlling the charging or discharging of the supercapacitor energy storage system according to the output frequency includes:

[0011] Subtracting the output frequency from the set standard frequency to obtain a frequency deviation;

[0012] Determine whether the frequency deviation is greater than a first frequency threshold, and if so, control the supercapacitor energy storage system to charge;

[0013] Determine whether the frequency deviation is less than a second frequency threshold, and if so, control the supercapacitor energy storage system to discharge.

[0014] Preferably, controlling the charging of the supercapacitor energy storage system includes: monitoring the storage capacity of the supercapacitor energy storage system during the charging process; determining whether the storage capacity is greater than a first set capacity, and if so, controlling the supercapacitor energy storage system to stop charging;

[0015] The controlling the supercapacitor energy storage system to discharge includes: detecting the storage capacity of the supercapacitor energy storage system during the discharge process; judging whether the storage capacity is less than a second set capacity, and if so, controlling the supercapacitor energy storage system to stop charging.

[0016] Preferably, the controlling the charging or discharging of the supercapacitor energy storage system further includes:

[0017] Calculating the frequency modulation required power according to the frequency deviation;

[0018] Calculating the charge and discharge load according to the power of the supercapacitor energy storage system;

[0019] Subtracting the frequency modulation required power from the charge and discharge load to obtain a capacitance capacity difference;

[0020] Determining whether the capacitance capacity difference is greater than a frequency modulation power threshold, and determining whether a sum of the capacitance capacity difference and the current power of the generator is greater than an upper limit power;

[0021] When the capacitance capacity difference is greater than the frequency modulation power threshold or the total power is greater than the upper limit power, the supercapacitor energy storage system is controlled to stop discharging or charging and the frequency modulation function is deactivated once.

[0022] Preferably, the controlling the charging or discharging of the supercapacitor energy storage system further includes:

[0023] It is determined whether the current power is less than a lower power threshold. If so, the supercapacitor energy storage system is controlled to stop discharging and the frequency modulation function is deactivated.

[0024] Preferably, the first frequency threshold is 0.067 Hz, the second frequency threshold is -0.067 Hz, the first set power is 95%, and the second set power is 20%.

[0025] Preferably, in controlling the charging or discharging of the supercapacitor energy storage system according to the output frequency, the method further includes:

[0026] When the frequency deviation is less than or equal to the first frequency threshold and greater than or equal to the second frequency threshold, the storage capacity of the supercapacitor energy storage system is controlled to be maintained within a set capacity range.

[0027] Preferably, before the emergency power supply system is started, controlling the supercapacitor energy storage system to supply power to the emergency bus includes:

[0028] When entering the second mode, controlling the supercapacitor energy storage system to supply power to the emergency bus, and simultaneously obtaining the real-time operating condition of the emergency power supply system;

[0029] Determine whether the operating condition of the emergency power supply system meets the switching requirements according to the real-time operating condition, and if so, the emergency bus is switched to be powered by the emergency power supply system;

[0030] After the power supply is switched, the supercapacitor energy storage system is charged and maintained within a set power range.

[0031] The present invention also constructs a nuclear power plant frequency regulation and emergency power supply control system, comprising:

[0032] A supercapacitor energy storage system comprising a plurality of supercapacitors;

[0033] a state switching unit, configured to obtain real-time operating information of the generator, determine whether the generator is operating normally according to the real-time operating information, and enter the first mode if the generator is operating normally, otherwise enter the second mode; the real-time operating information includes an output frequency;

[0034] a frequency modulation control unit, configured to, in the first mode, control the supercapacitor energy storage system to be connected to the output bus of the generator, and control the supercapacitor energy storage system to charge or discharge according to the output frequency, so that the output frequency is stabilized within a set frequency range;

[0035] The emergency power supply control unit is used to control the supercapacitor energy storage system to be connected to the emergency bus in the second mode, and to control the supercapacitor energy storage system to supply power to the emergency bus before the emergency power supply system is started.

[0036] Preferably, the supercapacitors are connected to each other to form a capacitor array;

[0037] The supercapacitor energy storage system also includes an inverter and a transformer;

[0038] The inverter is connected to the capacitor array and is used to convert the DC voltage output by the capacitor array into an AC voltage;

[0039] The transformer is connected to the inverter and is used for boosting the AC voltage and inputting the boosted AC voltage to the output bus or the emergency bus.

[0040] The implementation of the present invention has the following beneficial effects: by setting the working mode through the real-time operating information of the generator, seamless coordination of the two functions of frequency regulation and emergency power supply is achieved, which can not only significantly improve the frequency regulation response speed of the generator and shorten the frequency regulation time, but also improve the success rate of the emergency power supply system when emergency power supply is required, and can effectively improve the safety and reliability of the nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0042] Figure 1 is a flowchart of a method for controlling frequency regulation and emergency power supply in a nuclear power plant in some embodiments of the present invention;

[0043] Figure 2 is a flowchart of a program for controlling the charging or discharging of a supercapacitor energy storage system in some embodiments of the present invention;

[0044] Figure 3 It is a structural diagram of a nuclear power plant frequency regulation and emergency power supply control method in some embodiments of the present invention. DETAILED DESCRIPTION

[0045] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0046] It should be noted that the flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all content and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0047] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0048] Figure 1This is a flowchart of a method for controlling frequency regulation and emergency power supply in a nuclear power plant according to some embodiments of the present invention. This method, when applied to a supercapacitor energy storage system, can significantly improve the generator's frequency regulation response speed, shorten the frequency regulation duration, and increase the success rate of the emergency power supply system's cut-in when emergency power is needed. Furthermore, the supercapacitor energy storage system can include multiple supercapacitors, each of which can be connected in series.

[0049] like Figure 1 As shown, the nuclear power plant frequency regulation and emergency power supply control method may include step S1, step S2, step S3 and step S4.

[0050] Step S1 involves acquiring real-time operating information about the generator; this information includes the generator's output frequency, output voltage, current power, and active power. In this step, real-time operating information is routinely monitored at the nuclear power plant and can be acquired through communication with relevant systems (such as the DCS). It should be noted that the output frequency is a real-time parameter that changes with the generator's real-time operating status.

[0051] Step S2 includes: determining whether the generator is operating normally according to the real-time operating information, and if so, entering the first mode, otherwise entering the second mode.

[0052] In some embodiments, abnormal generator operation can be determined when a generator experiences an anomaly such as a shutdown or undervoltage. For example, when the generator's output voltage or current power decreases to a certain value (even close to zero), this indicates a generator anomaly. It should be noted that determining whether a generator anomaly such as undervoltage has occurred based on real-time operating information such as output voltage and current power is a mature technology in nuclear power plants and can be referenced in existing technologies. This will not be further elaborated here.

[0053] Step S3 includes: in the first mode, controlling the supercapacitor energy storage system to be connected to the output bus of the generator, and controlling the supercapacitor energy storage system to charge or discharge according to the output frequency, so that the output frequency is stabilized within the set frequency range. In this step, when the supercapacitor energy storage system is charging, it will draw power from the output bus of the generator, which is equivalent to increasing the load power of the generator, and when discharging, it will discharge to the output bus, which is equivalent to increasing the output power of the generator. Therefore, the charging and discharging of the supercapacitor energy storage system can be used to adjust the power balance between the generator and the load, thereby realizing the output frequency regulation of the generator. It is easy to understand that since the charging and discharging power of the supercapacitor energy storage system and the frequency deviation can be linearly related, the supercapacitor has the advantages of large instantaneous charging and discharging power and fast response, so the charging and discharging process of the supercapacitor energy storage system can quickly and accurately adjust the output frequency and improve the frequency modulation response speed.

[0054] It should be noted that the output busbar of the generator may be a power grid to which the power output terminal of the generator is connected.

[0055] In some embodiments, as Figure 2 As shown, the charging or discharging of the supercapacitor energy storage system can be controlled according to the output frequency by executing steps S31 to S33.

[0056] Step S31 includes: subtracting the output frequency from the set standard frequency to obtain a frequency deviation. In this step, the set standard frequency can be 50 Hz.

[0057] Step S32 includes: determining whether the frequency deviation is greater than a first frequency threshold, and if so, controlling the supercapacitor energy storage system to charge.

[0058] In some embodiments, the first frequency threshold can be 0.067 Hz. Of course, the first frequency threshold can also be customized according to needs. The first frequency threshold is a value greater than 0 Hz. The smaller the first frequency threshold, the more conducive it is to stabilize the output frequency of the generator at around the set standard frequency. Accordingly, the charging frequency of the supercapacitor energy storage system may be higher, which will lead to increased system losses.

[0059] To prevent the supercapacitor energy storage system from overcharging, in some embodiments, the following steps may be performed during the process of controlling the charging of the supercapacitor energy storage system: monitoring the storage capacity of the supercapacitor energy storage system during the charging process; determining whether the storage capacity is greater than a first set capacity, and if so, controlling the supercapacitor energy storage system to stop charging. In this embodiment, when the storage capacity reaches the first set capacity, if the supercapacitor energy storage system is continued to be used for charging and the output frequency is reduced, the supercapacitor energy storage system may be overcharged, causing capacitor overload and even safety issues. Therefore, it is necessary to stop the supercapacitor energy storage system from drawing power from the output bus to protect the supercapacitor energy storage system.

[0060] Due to the differences in performance of each supercapacitor in the supercapacitor energy storage system, for example, when some supercapacitors are charged to 98%, other supercapacitors may have been charged to 100%. To minimize overcharging of the supercapacitors, the first set power is set to a value less than 100%. Preferably, it is set to 95% to leave sufficient margin to ensure the safety of the supercapacitor energy storage system.

[0061] Since the output frequency may still have a positive frequency difference after the storage capacity reaches the first set capacity, in order to stabilize the output frequency, in some embodiments, when the supercapacitor energy storage system stops charging, the existing nuclear power plant frequency regulation control system can be enabled to utilize the existing equipment of the nuclear power plant to achieve frequency reduction.

[0062] Step S33 includes: determining whether the frequency deviation is less than a second frequency threshold, and if so, controlling the supercapacitor energy storage system to discharge.

[0063] In some embodiments, the second frequency threshold can be -0.067 Hz. Of course, the second frequency threshold can also be customized according to needs. The second frequency threshold is a value less than 0 Hz. The larger the second frequency threshold, the more conducive it is to stabilizing the output frequency of the generator at around the set standard frequency. Correspondingly, the charging frequency of the supercapacitor energy storage system may be higher, which will lead to increased system losses.

[0064] In order to avoid over-discharge of the supercapacitor energy storage system, in some embodiments, the following steps can also be performed in the process of controlling the discharge of the supercapacitor energy storage system: detecting the storage capacity of the supercapacitor energy storage system during the discharge process; judging whether the storage capacity is less than a second set capacity, and if so, controlling the supercapacitor energy storage system to stop charging, and controlling the nuclear power plant frequency regulation control system to enable.

[0065] In some embodiments, the second set power level may be 20%.

[0066] In order to further improve safety, in some embodiments, the following steps can also be performed in the process of controlling the charging or discharging of the supercapacitor energy storage system: calculating the frequency modulation power requirement based on the frequency deviation; calculating the charging and discharging load based on the power of the supercapacitor energy storage system; subtracting the frequency modulation power requirement from the charging and discharging load to obtain a capacitance capacity difference; judging whether the capacitance capacity difference is greater than the frequency modulation power threshold, and judging whether the total power after adding the capacitance capacity difference and the current power of the generator is greater than the upper limit power; when the capacitance capacity difference is greater than the frequency modulation power threshold or the total power is greater than the upper limit power, controlling the supercapacitor energy storage system to stop discharging or charging, and deactivating the frequency modulation function once.

[0067] Specifically, the expression of the frequency modulation required power can be: ΔP req =K*△f,△P req represents the frequency modulation power requirement, K represents the frequency modulation coefficient (which can be determined through actual testing and entered in advance), and △f represents the frequency deviation. The expression of the charge and discharge load can be: Psc represents the charge and discharge load, P sc，charge，max Indicates the maximum charging power during the charging process, P sc，discharge，max Indicates the maximum discharge power during the charging process. It is understandable that this embodiment also uses existing technologies to monitor the charging power and discharge power of the supercapacitor energy storage system in real time. The expression for the upper limit power can be: Pmax = λ*Prared, where Pmax represents the upper limit power, λ represents the frequency regulation capability value (which can be determined through actual testing and entered in advance), and Prared represents the power value when the generator is at full power output.

[0068] It should be noted that when the capacitance capacity difference is greater than the frequency modulation power threshold or the total power is greater than the upper limit power, if the supercapacitor energy storage system is discharging, it will immediately stop discharging; if the supercapacitor energy storage system is charging, it will immediately stop charging and output an alarm signal to alert the staff.

[0069] When the generator needs to be shut down for maintenance or related tests, the current power may drop to a relatively low value, and there is no need to perform frequency modulation at this time. Accordingly, in some embodiments, the following steps are also performed in the process of controlling the charging or discharging of the supercapacitor energy storage system: determining whether the current power is less than the lower power threshold; if so, controlling the supercapacitor energy storage system to stop discharging and deactivating the frequency modulation function.

[0070] In some embodiments, the lower power threshold may be 30%.

[0071] In some embodiments, as Figure 2 As shown, the process of controlling the charging or discharging of the supercapacitor energy storage system according to the output frequency may also include: S34, when the frequency deviation is less than or equal to the first frequency threshold and greater than or equal to the second frequency threshold, controlling the storage capacity of the supercapacitor energy storage system to remain within the set capacity range.

[0072] In some embodiments, the set power range may be 40% to 60%.

[0073] Step S4 includes: in the second mode, controlling the supercapacitor energy storage system to connect to the emergency bus and, before the emergency power system starts up, controlling the supercapacitor energy storage system to supply power to the emergency bus. This step ensures that during the startup phase of the emergency power system, before it fails to deliver stable emergency power, the supercapacitor energy storage system provides stable power to essential equipment responsible for maintaining nuclear power plant safety. The system then switches back on after the emergency power system has completed startup, thereby improving the success rate of the emergency power system's switch-on.

[0074] In some embodiments, the step of controlling the supercapacitor energy storage system to supply power to the emergency bus before the emergency power supply system is started may include: controlling the supercapacitor energy storage system to supply power to the emergency bus when entering the second mode, and obtaining the real-time operating conditions of the emergency power supply system at the same time; determining whether the operating conditions of the emergency power supply system meet the switching requirements based on the real-time operating conditions, and if so, the emergency bus is switched to be powered by the emergency power supply system; after the power switching is completed, charging the supercapacitor energy storage system and maintaining it within the set power range.

[0075] In some embodiments, when the emergency power system is powered by a diesel generator, the switching requirement may include the diesel generator speed reaching at least 80% of the rated speed. When the emergency power system is powered by a battery pack or an external power source, the switching requirement may also include the emergency power system output voltage amplitude being stable within a corresponding preset voltage range. For example, if the emergency bus voltage level is 10.5 kV, the preset voltage range may be 10.5 kV ± 0.5 kV.

[0076] In addition, the present invention returns to step S1 after each execution of step S3 or step S4 to update the real-time operation information of the generator so as to quickly enter the first mode or the second mode based on actual conditions to ensure stable operation of the nuclear power plant.

[0077] like Figure 3 As shown, the present invention also provides a nuclear power plant frequency regulation and emergency power supply control system, which may include a supercapacitor energy storage system 1, a state switching unit 2, a frequency regulation control unit 3 and an emergency power supply control unit 4.

[0078] The supercapacitor energy storage system 1 may include multiple supercapacitors. The supercapacitors may be connected in series or in a combination of series and parallel, and the supercapacitors may be connected to form a capacitor array.

[0079] In some embodiments, the number of supercapacitors can be 100, and the supercapacitors can be 2.7V / 3000F supercapacitors. Accordingly, the supercapacitors are connected in series to form a capacitor array capable of outputting a rated power of 500kW to 1000kW and a rated voltage of 380V to 400V, with a discharge time of 15s to 30s, ensuring that the emergency power supply system has sufficient time to start and output stable emergency power.

[0080] It should be noted that supercapacitors have the advantages of high power density (≥10kW / kg), long life (≥10 years maintenance-free), wide temperature operating range (-40℃~+65℃) and no risk of chemical reactions. They are particularly suitable for use in scenarios with high reliability and high safety required by nuclear power plants.

[0081] The state switching unit 2 is used to obtain real-time operation information of the generator to determine whether the generator is operating normally according to the real-time operation information, and enter the first mode when the generator is operating normally, otherwise enter the second mode; the real-time operation information includes the output frequency.

[0082] The frequency modulation control unit 3 is used to control the supercapacitor energy storage system 1 to be connected to the output bus of the generator in the first mode, and to control the charging or discharging of the supercapacitor energy storage system according to the output frequency, so that the output frequency is stabilized within a set frequency range. The specific method of the frequency modulation control unit 3 controlling the charging or discharging of the supercapacitor energy storage system according to the output frequency can be referred to in the above embodiment and will not be repeated here.

[0083] The emergency power supply control unit 4 is configured to control the supercapacitor energy storage system 1 to connect to the emergency bus in the second mode, and to control the supercapacitor energy storage system to supply power to the emergency bus before the emergency power supply system is activated. The specific method by which the emergency power supply control unit 4 controls the supercapacitor energy storage system to supply power to the emergency bus before the emergency power supply system is activated can be found in the above embodiment and will not be repeated here.

[0084] In some embodiments, the supercapacitor energy storage system 1 may further include an inverter and a transformer. The inverter is connected to the capacitor array and is used to convert the DC voltage output by the capacitor array into AC voltage. The transformer is connected to the inverter and is used to boost the AC voltage and input the boosted AC voltage to the output bus or emergency bus.

[0085] In some embodiments, the inverter may be an ABB ACS880-01-325A-3 inverter, and the transformer may be an existing step-up transformer with a transformation ratio of 0.4 kV / 10.5 kV.

[0086] In some embodiments, the state switching unit 2 may include a first control switch and a second control switch. The first control switch is connected between the output bus of the generator and the supercapacitor energy storage system 1, and is used to connect the connection between the supercapacitor energy storage system 1 and the output bus of the generator when entering the first mode, and disconnect the connection between the supercapacitor energy storage system 1 and the output bus of the generator when entering the second mode. The second control switch is connected between the emergency bus of the emergency power supply system and the supercapacitor energy storage system 1, and is used to disconnect the connection between the supercapacitor energy storage system 1 and the emergency bus when entering the first mode, and connect the connection between the supercapacitor energy storage system 1 and the emergency bus when entering the second mode. Among them, the frequency modulation control unit 3 is used to output instructions for controlling the on and off of the first control switch, and the emergency power supply control unit 4 is used to output instructions for controlling the on and off of the second control switch.

[0087] In some embodiments, the first control switch and the second control switch can both be composed of switching devices such as contactors and circuit breakers.

[0088] In an embodiment of the present invention, the working mode is set by using the real-time operating information of the generator, thereby achieving seamless coordination of the two functions of frequency regulation and emergency power supply. This can not only significantly improve the frequency regulation response speed of the generator and shorten the frequency regulation time, but also improve the success rate of the emergency power supply system when emergency power supply is required, thereby effectively improving the safety and reliability of the nuclear power plant.

[0089] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0090] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0091] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0092] It can be understood that the above embodiments only express the preferred implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can be made, all of which fall within the scope of protection of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A method for controlling frequency modulation and emergency power supply in a nuclear power plant, characterized in that: For a supercapacitor energy storage system comprising a plurality of supercapacitors, the method comprises: Acquiring real-time operating information of the generator; the real-time operating information includes output frequency; determining whether the generator is operating normally according to the real-time operating information, and if so, entering the first mode, otherwise entering the second mode; In the first mode, the supercapacitor energy storage system is controlled to be connected to the output bus of the generator, and the supercapacitor energy storage system is controlled to charge or discharge according to the output frequency, so that the output frequency is stabilized within a set frequency range; In the second mode, the supercapacitor energy storage system is controlled to be connected to the emergency bus, and before the emergency power supply system is started, the supercapacitor energy storage system is controlled to supply power to the emergency bus.

2. The nuclear power plant frequency modulation and emergency power supply control method according to claim 1, characterized in that: The controlling the charging or discharging of the supercapacitor energy storage system according to the output frequency includes: Subtracting the output frequency from the set standard frequency to obtain a frequency deviation; Determine whether the frequency deviation is greater than a first frequency threshold, and if so, control the supercapacitor energy storage system to charge; Determine whether the frequency deviation is less than a second frequency threshold, and if so, control the supercapacitor energy storage system to discharge.

3. The nuclear power plant frequency modulation and emergency power supply control method according to claim 2, characterized in that: The controlling the charging of the supercapacitor energy storage system includes: monitoring the storage capacity of the supercapacitor energy storage system during the charging process; determining whether the storage capacity is greater than a first set capacity, and if so, controlling the supercapacitor energy storage system to stop charging; The controlling the supercapacitor energy storage system to discharge includes: detecting the storage capacity of the supercapacitor energy storage system during the discharge process; judging whether the storage capacity is less than a second set capacity, and if so, controlling the supercapacitor energy storage system to stop charging.

4. The nuclear power plant frequency modulation and emergency power supply control method according to claim 3, characterized in that: In controlling the charging or discharging of the supercapacitor energy storage system, the method further includes: Calculating the frequency modulation required power according to the frequency deviation; Calculating the charge and discharge load according to the power of the supercapacitor energy storage system; Subtracting the frequency modulation required power from the charge and discharge load to obtain a capacitance capacity difference; Determining whether the capacitance capacity difference is greater than a frequency modulation power threshold, and determining whether a sum of the capacitance capacity difference and the current power of the generator is greater than an upper limit power; When the capacitance capacity difference is greater than the frequency modulation power threshold or the total power is greater than the upper limit power, the supercapacitor energy storage system is controlled to stop discharging or charging and the frequency modulation function is deactivated once.

5. The nuclear power plant frequency modulation and emergency power supply control method according to claim 4, characterized in that: In controlling the charging or discharging of the supercapacitor energy storage system, the method further includes: It is determined whether the current power is less than a lower power threshold. If so, the supercapacitor energy storage system is controlled to stop discharging and the frequency modulation function is deactivated.

6. The nuclear power plant frequency modulation and emergency power supply control method according to claim 5, characterized in that: The first frequency threshold is 0.067 Hz, the second frequency threshold is -0.067 Hz, the first set power is 95%, and the second set power is 20%.

7. The nuclear power plant frequency modulation and emergency power supply control method according to claim 2, characterized in that: In controlling the charging or discharging of the supercapacitor energy storage system according to the output frequency, the method further includes: When the frequency deviation is less than or equal to the first frequency threshold and greater than or equal to the second frequency threshold, the storage capacity of the supercapacitor energy storage system is controlled to be maintained within a set capacity range.

8. The nuclear power plant frequency modulation and emergency power supply control method according to any one of claims 1 to 7, characterized in that: Before the emergency power supply system is started, controlling the supercapacitor energy storage system to supply power to the emergency bus includes: When entering the second mode, controlling the supercapacitor energy storage system to supply power to the emergency bus, and simultaneously obtaining the real-time operating condition of the emergency power supply system; Determine whether the operating condition of the emergency power supply system meets the switching requirements according to the real-time operating condition, and if so, the emergency bus is switched to be powered by the emergency power supply system; After the power supply is switched, the supercapacitor energy storage system is charged and maintained within a set power range.

9. A nuclear power plant frequency modulation and emergency power supply control system, characterized in that: include: A supercapacitor energy storage system comprising a plurality of supercapacitors; a state switching unit, configured to obtain real-time operating information of the generator, determine whether the generator is operating normally according to the real-time operating information, and enter the first mode if the generator is operating normally, otherwise enter the second mode; the real-time operating information includes an output frequency; a frequency modulation control unit, configured to, in the first mode, control the supercapacitor energy storage system to be connected to the output bus of the generator, and control the supercapacitor energy storage system to charge or discharge according to the output frequency, so that the output frequency is stabilized within a set frequency range; The emergency power supply control unit is used to control the supercapacitor energy storage system to be connected to the emergency bus in the second mode, and to control the supercapacitor energy storage system to supply power to the emergency bus before the emergency power supply system is started.

10. The nuclear power plant frequency regulation and emergency power supply control system according to claim 9, characterized in that: The supercapacitors are connected to each other to form a capacitor array; The supercapacitor energy storage system also includes an inverter and a transformer; The inverter is connected to the capacitor array and is used to convert the DC voltage output by the capacitor array into an AC voltage; The transformer is connected to the inverter and is used for boosting the AC voltage and inputting the boosted AC voltage to the output bus or the emergency bus.

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