Method and system for configuring optical storage subsection combined security power supply for thermal power

Abstract

The invention discloses a thermal power configuration optical storage segmented combined security power supply method and system, and relates to the technical field of security power supplies, and the method comprises the steps: connecting a photovoltaic bus, an energy storage bus and a security power supply bus, and forming a three-bus system connected with an interconnection circuit breaker; the photovoltaic energy storage system is set as a backup power supply of the security power supply through an interconnection circuit breaker; the photovoltaic energy storage system is connected to the thermal power generating unit for frequency modulation, and meanwhile the photovoltaic system serves as a controllable load to participate in frequency modulation; a load shedding control strategy is implemented in a photovoltaic system, and active power support is provided for a power grid. According to the invention, the photovoltaic 400V alternating current bus, the energy storage 400V alternating current bus and the 400V security power supply bus are connected through the interconnection circuit breaker, so that photovoltaic energy storage can be used as a backup power supply system of a low-voltage 400V security power supply. And when the 400V security load does not work or the capacity is insufficient, the power supply can be quickly switched to the optical storage system for power supply, so that the reliability of station low-voltage power supply is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of security power supply, in particular to a method and system for a security power supply with a thermal power generation system configured with a photovoltaic power plant and a storage system. Background Art

[0002] At present, the typical design of the power supply system of large thermal power units usually includes a step-down transformer at the generator outlet, which gradually steps down the voltage from the high voltage (such as 20kV) at the generator outlet to the low voltage (such as 6kV and 400V) required by the power supply system. This design uses an industrial frequency transformer, which mainly involves the use of alternating current.

[0003] However, as the capacity of the units continues to increase, the capacity of the plant power system is also continuously expanding. The capacity of the high-voltage plant transformer (i.e., high-voltage plant transformer) has increased accordingly, resulting in a significant increase in the short-circuit current of the plant power system. This places higher demands on the short-circuit breaking capacity of the high-voltage switch. At the same time, in order to meet the requirements of short-circuit thermal stability, the high-voltage cables of the plant power system need to be thicker, which undoubtedly increases the investment cost.

[0004] In addition, traditional high-voltage power plant transformers use industrial frequency transformers, which are large in size and often require capacity expansion when the power system capacity needs to be increased. The cost of the transformation is high, the construction period is long, and it will delay the normal power generation of the power plant.

[0005] In this context, the traditional AC power supply system faces some development bottlenecks and urgently needs new technical solutions. Compared with the traditional AC power supply system, the DC networking form is considered to have many advantages. For example, the power supply capacity of the DC network is larger, and there is no need to consider the phase angle and frequency issues, and asynchronous system interconnection can be realized. The power supply load is connected to the DC power supply system through the rectifier, which can improve the power conversion efficiency, reduce equipment loss, and realize load variable frequency drive, thereby simplifying the internal circuit of the load and reducing the failure rate and equipment cost.

[0006] The present invention proposes a thermal power configuration photovoltaic storage segmented joint security power supply method and system, aiming to utilize the advantages of photovoltaic and energy storage systems, solve the problems existing in traditional AC plant power systems, and improve the reliability and economy of plant power systems. Summary of the invention

[0007] In view of the above-mentioned problems, the present invention is proposed.

[0008] Therefore, the problem to be solved by the present invention is: how to solve the problem that the traditional high-voltage power plant transformer uses an industrial frequency transformer, which is bulky and often needs to be remodeled when the capacity of the power system needs to be increased. The cost of the remodeling is high, the construction period is long, and the normal power generation of the power plant is delayed.

[0009] To solve the above technical problems, the present invention provides the following technical solutions: a method for configuring a photovoltaic and energy storage segmented joint security power supply for thermal power generation, comprising: connecting a photovoltaic bus, an energy storage bus and a security power supply bus to form a three-bus system connected by interconnected circuit breakers; setting the photovoltaic energy storage system as a backup power supply for the security power supply through the interconnected circuit breaker; connecting the photovoltaic energy storage system to the frequency modulation of the thermal power unit, and at the same time making the photovoltaic system participate in the frequency modulation as a controllable load; implementing a load reduction control strategy in the photovoltaic system to provide active power support for the power grid; the load reduction control strategy includes improving the control system of the plant photovoltaic inverter and introducing a load reduction control strategy without changing the main circuit structure and the inverter grid connection strategy.

[0010] As a preferred solution of the method for configuring photovoltaic and storage segmented combined security power supply for thermal power generation described in the present invention, the photovoltaic energy storage system includes constructing a photovoltaic energy storage system for a thermal power plant, connecting the photovoltaic AC bus, the energy storage AC bus and the security power bus through an interconnecting circuit breaker, so that the photovoltaic energy storage is used as a security power backup power system to reduce the power consumption rate of the plant, and the energy storage assists the thermal power units in frequency regulation, and the photovoltaic energy storage participates in the frequency regulation of the thermal power units as a controllable load.

[0011] As a preferred solution of the method of configuring photovoltaic and storage segmented combined security power supply for thermal power generation described in the present invention, wherein: the use of photovoltaic energy storage as a security power backup power supply system includes using the photovoltaic energy storage system as a security power backup power supply to provide security power supply reliability. When the security load is not working or the capacity is insufficient, the photovoltaic energy storage system's electric energy is transmitted to the security power bus by closing the interconnected circuit breaker to ensure the reliability of the factory's low-voltage power supply.

[0012] As a preferred solution of the method for configuring a photovoltaic and storage segmented joint security power supply for thermal power generation according to the present invention, the improvement of the photovoltaic inverter control system for the plant includes performing load reduction control in the photovoltaic inverter control system, and the active standby power is expressed as: , in, is the photovoltaic backup power, is the load reduction rate, is the number of PV arrays connected in parallel, The reference power provided for the photovoltaic main array; the active reserve power required for load reduction control is controlled by Change, that is, change the active output by controlling the load reduction rate, set Corresponding relationship, by detecting the fluctuation of the factory photovoltaic bus frequency and changing the load reduction rate, active power support is achieved.

[0013] As a preferred solution of the method for configuring thermal power generation with photovoltaic and storage segmented joint security power supply described in the present invention, wherein: the load reduction rate is included in the photovoltaic inverter control system, the plant photovoltaic bus voltage frequency is detected by the PLL phase-locked loop, and the load reduction rate is changed according to the frequency change; when the plant photovoltaic bus voltage frequency is greater than the rated value, the photovoltaic power generation load reduction rate is increased, that is, the active power output is reduced; when the plant photovoltaic bus voltage frequency is less than the rated value, the load reduction rate is reduced, that is, the active power output is increased; to achieve the same frequency adjustment range as the thermal power unit, a frequency adjustment dead zone is set in the photovoltaic inverter frequency control link, and different load reduction rates are set according to different frequency drop depths to achieve dynamic frequency adjustment.

[0014] As a preferred solution of the thermal power configuration photovoltaic storage segmented joint security power supply method of the present invention, the load reduction rate is expressed as: , in, is the output frequency of the photovoltaic inverter, F is the relationship between the load reduction rate and frequency in the corresponding interval, , Respectively represent the maximum and minimum frequencies allowed, Indicates the normal frequency fluctuation range, is the standard value of load reduction rate, is the minimum load reduction rate, is the calculated value of load reduction rate for large frequency fluctuations, is the calculated value of load reduction rate for small range frequency fluctuation, is the maximum load reduction rate.

[0015] Another object of the present invention is to provide a system for the method of configuring a thermal power plant with a photovoltaic and storage segmented joint security power supply, which can solve the problem of configuring a thermal power plant with a photovoltaic and storage segmented joint security power supply by constructing a thermal power plant with a photovoltaic and storage segmented joint security power supply system.

[0016] In order to solve the above technical problems, the present invention provides the following technical solutions: a thermal power configuration photovoltaic storage segmented joint security power supply system, including a thermal power plant start-up standby transformer unit and a distributed photovoltaic energy storage security segment access unit; the generator in the thermal power plant start-up standby transformer unit is connected to the power grid system through a main transformer, a plant high-voltage transformer is arranged at the generator outlet, and the voltage is stepped down and connected to the plant bus, the power grid system is connected to the high-voltage side of the start-up standby transformer, the start-up standby transformer is stepped down, and the low-voltage side of the start-up standby transformer is connected to the plant bus; the plant bus in the distributed photovoltaic energy storage security segment access unit is connected to the thermal power plant start-up standby transformer The low-voltage side of the plant high-voltage transformer and the starting standby transformer in the unit, the photovoltaic panels are connected to the photovoltaic bus through the inverter, the energy storage module is connected to the energy storage bus through the converter, the security load is connected to the security power bus through the security load access switch, the photovoltaic AC bus, the energy storage AC bus and the security power bus are connected through the interconnection circuit breaker, the photovoltaic AC bus is connected to the low-voltage side of the photovoltaic boost transformer, the high-voltage side of the photovoltaic boost transformer is connected to the plant bus, the energy storage AC bus is connected to the low-voltage side of the energy storage boost transformer, the high-voltage side of the energy storage boost transformer is connected to the plant bus, the security power bus is connected to the low-voltage side of the low-plant transformer, and the high-voltage side of the low-plant transformer is connected to the plant bus.

[0017] A computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method for configuring a thermal power plant with a photovoltaic and storage segmented combined security power supply are implemented as described above.

[0018] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for configuring a thermal power plant with a photovoltaic and storage segmented combined security power supply as described above.

[0019] The beneficial effects of the present invention are as follows: the thermal power configuration photovoltaic storage segmented combined security power supply method provided by the present invention brings many beneficial effects, which are specifically detailed as follows: 1) Improve power supply reliability and flexibility: By connecting the photovoltaic 400V AC bus, energy storage 400V AC bus and 400V security power bus through interconnected circuit breakers, this system allows photovoltaic energy storage to be used as a backup power system for the low-voltage 400V security power supply. When the 400V security load is not working or the capacity is insufficient, it can be quickly switched to the photovoltaic storage system for power supply, thereby greatly improving the reliability of the low-voltage power supply for the factory.

[0020] 2) Reduce power consumption and costs: Configuring photovoltaic and energy storage equipment in the power system of the factory can effectively reduce the dependence on traditional power sources, thereby reducing the power consumption rate of the factory. At the same time, the introduction of photovoltaic and energy storage can optimize the distribution of power loads, reduce power demand during peak hours, and help reduce power costs.

[0021] 3) Support frequency regulation of thermal power units and grid stability: Energy storage equipment can not only serve as a backup power source, but also assist thermal power units in frequency regulation. When the grid frequency fluctuates, energy storage equipment can respond quickly, release or absorb electric energy, and thus help maintain the stability of the grid frequency. In addition, photovoltaic systems can also participate in the frequency regulation of thermal power units as controllable loads, further enhancing the stability of the grid.

[0022] 4) Simplify circuit structure and reduce failure rate: Compared with the traditional AC power plant system, the DC networking proposed in the present invention has many advantages. DC networking does not need to consider phase angle and frequency, and can realize asynchronous system interconnection. The power plant load is connected to the DC power plant system through a rectifier, which can simplify the circuit structure, reduce equipment loss, and reduce the failure rate.

[0023] 5) Improve power conversion efficiency and equipment utilization: The DC network can also improve the efficiency of power conversion, because DC power has less loss during transmission. In addition, the introduction of photovoltaic and energy storage equipment can make the equipment utilization rate of the factory power system more efficient, reducing idleness and waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0025] Figure 1 A flow chart of a method for configuring a thermal power plant with photovoltaic and storage segmented combined security power supply provided in the first embodiment of the present invention.

[0026] Figure 2 This is a structural diagram of a thermal power generation and photovoltaic storage segmented combined safety power supply system provided for the second embodiment of the present invention.

[0027] In the figure: 100, thermal power plant start-up and standby transformer unit; 200, distributed photovoltaic energy storage security section access unit; 101, generator #1; 102, main transformer #1; 103, 330kV power grid system; 104, plant high-voltage transformer; 105, start-up and standby transformer; 201, 6kV plant bus; 202, photovoltaic access high-voltage side switch; 203, photovoltaic step-up transformer; 204, photovoltaic access low-voltage side switch; 205, 400V photovoltaic bus; 206, photovoltaic grid-connected switch; 207, photovoltaic inverter ; 208, photovoltaic panels; 209, photovoltaic low-voltage bus and energy storage low-voltage bus interconnection switch; 210, energy storage volt access high-voltage side switch; 211, energy storage step-up transformer; 212, energy storage access low-voltage side switch; 213, energy storage switch; 214, energy storage system AC cabinet; 215, energy storage module; 216, energy storage low-voltage bus and security power bus interconnection switch; 217, low-voltage plant transformer high-voltage side switch; 218, low-voltage plant transformer; 219, low-voltage plant transformer low-voltage side switch; 220, security load access switch; 221, security load. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Example 1, reference Figure 1 , which is the first embodiment of the present invention, provides a method for configuring a thermal power plant with a photovoltaic and energy storage segmented joint security power supply, including: connecting a photovoltaic bus, an energy storage bus and a security power supply bus to form a three-bus system connected by interconnected circuit breakers; setting the photovoltaic energy storage system as a backup power supply for the security power supply through the interconnected circuit breaker; connecting the photovoltaic energy storage system to the frequency modulation of the thermal power unit, and at the same time allowing the photovoltaic system to participate in the frequency modulation as a controllable load; implementing a load reduction control strategy in the photovoltaic system to provide active power support for the power grid.

[0031] S1, connect the photovoltaic bus, energy storage bus and security power bus to form a three-bus system connected by interconnected circuit breakers.

[0032] S2. By interconnecting the circuit breakers, the photovoltaic energy storage system is set as the backup power supply for the security power supply.

[0033] Construct a photovoltaic energy storage system for thermal power plants, connect the photovoltaic AC bus, energy storage AC bus and security power bus through interconnected circuit breakers, and use photovoltaic energy storage as a security power backup power system to reduce plant power consumption. Energy storage assists thermal power units in frequency regulation, and photovoltaics participate in the frequency regulation of thermal power units as a controllable load.

[0034] Specifically, a photovoltaic energy storage system is constructed for a thermal power plant. The photovoltaic 400V AC bus, the energy storage 400V AC bus and the 400V security power bus are connected through an interconnected circuit breaker. The photovoltaic energy storage can be used as a low-voltage 400V security power backup power system, and the power consumption rate of the plant can also be reduced. The energy storage can assist the thermal power units in frequency regulation, and the photovoltaic can also participate in the frequency regulation of the thermal power units as a controllable load.

[0035] S3. Connect the photovoltaic energy storage system to the frequency regulation of the thermal power unit, and at the same time make the photovoltaic system participate in the frequency regulation as a controllable load.

[0036] The photovoltaic energy storage system is used as a backup power source for the security power supply to provide security power supply reliability. When the security load is not working or the capacity is insufficient, the photovoltaic energy storage system power is transmitted to the security power bus by closing the interconnection circuit breaker to ensure the reliability of the factory's low-voltage power supply.

[0037] Specifically, the photovoltaic 400V AC bus, the energy storage 400V AC bus and the 400V security power bus are connected through an interconnection circuit breaker. The photovoltaic storage system can be used as a backup power supply for the 400V security power supply to provide security power supply reliability. When the 400V security load is not working or the capacity is insufficient, the photovoltaic storage system power is transmitted to the 400V security power bus by closing the interconnection circuit breaker to ensure the reliability of the factory's low-voltage power supply.

[0038] Configuring photovoltaics and energy storage in the plant power system can reduce the plant power consumption rate. Energy storage can assist thermal power units in frequency regulation, and photovoltaics can also participate in the frequency regulation of thermal power units as a controllable load.

[0039] S4. Implement load reduction control strategy in the photovoltaic system to provide active power support for the power grid.

[0040] The control system of the factory-used photovoltaic inverter is improved and a load reduction control strategy is introduced to enable the photovoltaic power station to support the factory-used bus frequency without changing the main circuit structure and the inverter grid-connected strategy.

[0041] When load shedding control is performed in the photovoltaic inverter control system, the active standby power is: , in, is the photovoltaic backup power, is the load reduction rate, is the number of PV arrays connected in parallel, The reference power provided for the photovoltaic main array; the active reserve power required for load reduction control is controlled by Change, that is, change the active output by controlling the load reduction rate, set Corresponding relationship, active power support can be achieved by detecting the fluctuation of the frequency of the 400V photovoltaic busbar in the factory to change the load reduction rate.

[0042] In the photovoltaic inverter control system, the current 400V bus voltage frequency of the photovoltaic power plant is detected through the PLL phase-locked loop, and the load reduction rate is changed according to the frequency change, so that the photovoltaic power plant has the ability to actively support the system frequency. When the 400V bus voltage frequency of the photovoltaic power plant is greater than the rated value, the photovoltaic power generation load reduction rate is increased, that is, the active power output is reduced. When the 400V bus voltage frequency of the photovoltaic power plant is less than the rated value, the load reduction rate is reduced, that is, the active power output is increased, providing inertia for the system. In order to achieve the same frequency regulation range as that of the thermal power unit, a frequency regulation dead zone is set in the frequency control link of the photovoltaic inverter. Different load reduction rates are set according to the depth of the frequency drop to achieve dynamic frequency regulation. The load reduction rate is expressed as: , in, is the output frequency of the photovoltaic inverter, F is the relationship between the load reduction rate and frequency in the corresponding interval, , Respectively represent the maximum and minimum frequencies allowed, Indicates the normal frequency fluctuation range, is the standard value of load reduction rate, is the minimum load reduction rate, is the calculated value of load reduction rate for large frequency fluctuations, is the calculated value of load reduction rate for small range frequency fluctuation, is the maximum load reduction rate.

[0043] The allowable frequency deviation of the power system is ±0.2Hz, so the setting , at this time the load reduction rate ,Pick , so that the system operates in maximum power point tracking mode, and all the reserve power of the photovoltaic system is sent to the system through load shedding to balance the system power. When the system frequency is greater than 50.2 Hz, the load reduction rate is set to the maximum to reduce the active power output of the system. . Set the normal fluctuation range of the system to ,Right now , in this interval the system operates at a fixed load reduction rate, let . , To connect within the corresponding interval , A function, set , .

[0044] Example 2, reference Figure 2 , which is the second embodiment of the present invention, is different from the previous embodiment in that it provides a thermal power configuration photovoltaic storage segmented joint safety power supply system, including: a thermal power plant start-up standby transformer unit 100 and a distributed photovoltaic energy storage safety segment access unit 200.

[0045] The generator in the starting standby transformer unit 100 of the thermal power plant is connected to the 330kV power grid system through the main transformer. A plant high-voltage transformer is arranged at the generator outlet to step down the 20kV voltage to 6kV and connect it to the 6kV plant bus. The 330kV power grid system is connected to the high-voltage side of the starting standby transformer. The starting standby transformer steps down the 330kV voltage to 6kV, and the low-voltage side of the starting standby transformer is connected to the 6kV plant bus.

[0046] The 6kV plant bus in the distributed photovoltaic energy storage security section access unit 200 is connected to the plant high-voltage transformer and the low-voltage side of the starting standby transformer in the thermal power plant standby transformer unit 100. The photovoltaic panels are connected to the 400V photovoltaic bus through the inverter, and the energy storage module is connected to the 400V energy storage bus through the converter. The security load is connected to the 400V security power bus through the security load access switch. The photovoltaic 400V AC bus, the energy storage 400V AC bus and the 400V security power bus are connected through the interconnection circuit breaker. The photovoltaic 400V AC bus is connected to the low-voltage side of the photovoltaic boost transformer, and the photovoltaic boost transformer high-voltage side is connected to the 6kV plant bus. The energy storage 400V AC bus is connected to the low-voltage side of the energy storage boost transformer, and the energy storage boost transformer high-voltage side is connected to the 6kV plant bus. The 400V security power bus is connected to the low-voltage side of the low-plant transformer, and the low-plant transformer high-voltage side is connected to the 6kV plant bus.

[0047] like Figure 2 As shown, 101 is the #1 generator, 102 is the #1 main transformer, 103 is the 330kV power grid system, 104 is the plant high-voltage transformer, and 105 is the starting standby transformer.

[0048] 201 is the 6kV plant bus, 202 is the photovoltaic access high-voltage side switch, 203 is the photovoltaic step-up transformer, 204 is the photovoltaic access low-voltage side switch, 205 is the 400V photovoltaic bus, 206 is the photovoltaic grid-connected switch, 207 is the photovoltaic inverter, 208 is the photovoltaic panel, 209 is the photovoltaic low-voltage bus and energy storage low-voltage bus interconnection switch, 210 is the energy storage volt access high-voltage side switch, 211 is the energy storage step-up transformer, 212 is the energy storage access low-voltage side switch, 213 is the energy storage switch, 214 is the energy storage system AC cabinet, 215 is the energy storage module, 216 is the energy storage low-voltage bus and the security power bus interconnection switch, 217 is the low-plant transformer high-voltage side switch, 218 is the low-plant transformer, 219 is the low-plant transformer low-voltage side switch, 220 is the security load access switch, and 221 is the security load.

[0049] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0050] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0051] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0052] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0053] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for combining thermal power generation with photovoltaic and energy storage for segmented security power supply, characterized in that: include, Connect the photovoltaic bus, energy storage bus and security power bus to form a three-bus system connected by interconnected circuit breakers; By interconnecting the circuit breakers, the photovoltaic energy storage system is set as a backup power source for the security power supply; Connect the photovoltaic energy storage system to the frequency regulation of thermal power units, and make the photovoltaic system participate in the frequency regulation as a controllable load; Implement load shedding control strategies in photovoltaic systems to provide active power support for the grid; The load shedding control strategy includes improving the control system of the plant-used photovoltaic inverter and introducing the load shedding control strategy without changing the main circuit structure and the inverter grid connection strategy.

2. The method for sectionalized joint security power supply of thermal power and photovoltaic and energy storage as claimed in claim 1 is characterized by: The photovoltaic energy storage system includes constructing a photovoltaic energy storage system for a thermal power plant, connecting a photovoltaic AC bus, an energy storage AC bus and a security power bus through an interconnection circuit breaker, so that the photovoltaic energy storage is used as a security power backup power system to reduce the power consumption rate of the plant, and the energy storage assists the thermal power unit in frequency regulation. Photovoltaics participates in the frequency regulation of the thermal power unit as a controllable load.

3. The method for sectionalized joint security power supply of thermal power and photovoltaic and energy storage as claimed in claim 2 is characterized by: The method of using photovoltaic energy storage as a backup power supply system for the security power supply includes using the photovoltaic energy storage system as a backup power supply for the security power supply to provide the reliability of the security power supply. When the security load is not working or the capacity is insufficient, the photovoltaic energy storage system power is transmitted to the security power bus by closing the interconnection circuit breaker to ensure the reliability of the low-voltage power supply for the factory.

4. The method for sectionalized joint security power supply of thermal power and photovoltaic and energy storage as claimed in claim 3 is characterized by: The improvement of the photovoltaic inverter control system for the plant includes that when load reduction control is performed in the photovoltaic inverter control system, the active standby power is expressed as: ， in, is the photovoltaic backup power, is the load reduction rate, is the number of PV arrays connected in parallel, Reference power provided for the photovoltaic main array; The active reserve power required for load shedding control is controlled by Change, that is, change the active output by controlling the load reduction rate, set Corresponding relationship, by detecting the fluctuation of the factory photovoltaic bus frequency and changing the load reduction rate, active power support is achieved.

5. The method for configuring a thermal power plant with a photovoltaic and energy storage system for a segmented combined security power supply as claimed in claim 4, characterized in that: The load reduction rate includes, in the photovoltaic inverter control system, detecting the factory photovoltaic bus voltage frequency through a PLL phase-locked loop, and changing the load reduction rate according to the frequency change; When the power plant photovoltaic bus voltage frequency is greater than the rated value, the photovoltaic power generation load reduction rate is increased, that is, the active power output is reduced; when the power plant photovoltaic bus voltage frequency is less than the rated value, the load reduction rate is reduced, that is, the active power output is increased; To achieve the same frequency regulation range as thermal power units, a frequency regulation dead zone is set in the frequency control link of the photovoltaic inverter. Different load reduction rates are set according to the depth of frequency drop to achieve dynamic frequency regulation.

6. The method for sectionalized joint security power supply of thermal power and photovoltaic and energy storage as claimed in claim 5, characterized in that: The load reduction rate is expressed as, ， in, is the output frequency of the photovoltaic inverter, F is the relationship between the load reduction rate and frequency in the corresponding interval, , Respectively represent the maximum and minimum frequencies allowed, Indicates the normal frequency fluctuation range, is the standard value of load reduction rate, is the minimum load reduction rate, is the calculated value of load reduction rate for large frequency fluctuations, is the calculated value of load reduction rate for small range frequency fluctuation, is the maximum load reduction rate.

7. A system using the method of thermal power generation and photovoltaic and storage segmented joint security power supply as claimed in any one of claims 1 to 6, characterized in that: It includes a thermal power plant standby transformer unit (100) and a distributed photovoltaic energy storage safety section access unit (200); The generator in the thermal power plant starting and standby transformer unit (100) is connected to the power grid system through a main transformer, a plant high-voltage transformer is arranged at the generator outlet, the voltage is stepped down and connected to the plant bus, the power grid system is connected to the high-voltage side of the starting and standby transformer, the starting and standby transformer steps down the voltage, and the low-voltage side of the starting and standby transformer is connected to the plant bus; The plant bus in the distributed photovoltaic energy storage security section access unit (200) is connected to the plant high-voltage transformer and the low-voltage side of the starting standby transformer in the thermal power plant start-up standby transformer unit (100), the photovoltaic panels are connected to the photovoltaic bus through the inverter, the energy storage module is connected to the energy storage bus through the converter, the security load is connected to the security power bus through the security load access switch, the photovoltaic AC bus, the energy storage AC bus and the security power bus are connected through the interconnection circuit breaker, the photovoltaic AC bus is connected to the photovoltaic boost transformer low-voltage side, the photovoltaic boost transformer high-voltage side is connected to the plant bus, the energy storage AC bus is connected to the energy storage boost transformer low-voltage side, the energy storage boost transformer high-voltage side is connected to the plant bus, the security power bus is connected to the low-voltage side of the low-plant transformer, and the low-plant transformer high-voltage side is connected to the plant bus.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for configuring a thermal power plant with photovoltaic and storage segments for joint security power supply according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for a segmented joint power supply for thermal power generation with photovoltaic and storage devices as described in any one of claims 1 to 6 are implemented.

Images