Fire storage combined frequency modulation system based on composite energy storage, condensate frequency modulation and boiler overshoot

Abstract

This invention relates to a combined thermal and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot. The system comprises: a composite energy storage subsystem, enabling different types of batteries to participate in different types of frequency regulation command requirements; a condensate throttling frequency regulation response subsystem, which participates in auxiliary regulation when the composite energy storage subsystem cannot meet the grid frequency regulation response requirements; a frequency regulation response subsystem, which controls the composite energy storage subsystem, condensate throttling frequency regulation response subsystem, boiler overshoot control subsystem, and turbine main steam control valve to jointly participate in frequency regulation response based on the received frequency regulation command and the actual unit output; and a boiler overshoot control subsystem, which sets an overshoot amount based on the load command when the frequency regulation response subsystem receives a long-duration, large-amplitude frequency regulation command, adjusting the amount of water and coal entering the boiler. Compared with existing technologies, this invention has advantages such as minimizing power generation coal consumption and equipment wear, improving the battery life of the energy storage system, and reducing initial investment costs.

Description

Technical Field

[0001] This invention relates to the field of frequency regulation technology for thermal power units, and in particular to a combined thermal power and storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot. Background Technology

[0002] With carbon peaking and carbon neutrality goals being upgraded to national strategies, economic and social development has begun a comprehensive green transformation. The installed capacity of new energy power sources such as wind power, photovoltaic power, and hydropower is continuing to grow rapidly. The volatility and intermittency of new energy power generation output are increasingly impacting the stable operation of the power grid. To ensure the safe and stable operation of the power grid, thermal power units, as a supporting power source, are receiving more frequent frequency regulation commands, and the demand for deeper frequency regulation is also increasing.

[0003] Thermal power units typically participate in frequency regulation response through load adjustment via main steam control valves. This method offers advantages such as timely response and large regulation capacity, but also disadvantages including significant throttling losses, high coal consumption, and severe equipment wear. In recent years, a combined thermal power and energy storage frequency regulation technology has emerged, such as... Figure 2 As shown, this technology typically uses lithium iron phosphate battery energy storage systems to assist in the frequency regulation response of thermal power units, in order to release the main steam valve opening to a certain extent and reduce valve throttling losses. However, through practical application, the combined thermal power and energy storage frequency regulation technology generally has the disadvantages of large battery capacity, high initial investment, short battery life, and poor economic efficiency. At the same time, its ability to release the main steam valve opening is limited, and the improvement of valve throttling losses is not significant. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a combined thermal power and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation and boiler overshoot. Through this invention, the main steam regulating valve of the thermal power unit can be fully opened, which can minimize the coal consumption and equipment wear of power generation. At the same time, it can also improve the battery life of the energy storage system and reduce the initial investment cost by comprehensively improving the battery life of the energy storage system through different types of energy storage systems.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A combined thermal power and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot is used to improve the load regulation mode of thermal power units participating in frequency regulation response through throttling of the main steam control valve. The boiler is connected to the steam turbine through the main steam control valve, the steam turbine is connected to the low-pressure heat exchanger, one end of the condenser is connected to the steam turbine, and the other end is connected to the low-pressure heat exchanger through the condensate pump. The other end of the low-pressure heat exchanger is connected to the boiler feedwater equipment. The system specifically includes:

[0007] A composite energy storage subsystem is used to enable different types of batteries to participate in different types of frequency regulation commands.

[0008] The condensate throttling frequency regulation response subsystem is used to participate in auxiliary regulation when the composite energy storage subsystem cannot meet the grid frequency regulation response requirements;

[0009] The frequency regulation response subsystem is used to control the composite energy storage subsystem, condensate throttling frequency regulation response subsystem, boiler overshoot control subsystem, and turbine main steam regulating valve in accordance with the received frequency regulation command and the actual output of the unit.

[0010] The boiler overshoot control subsystem connects the regulating valves between the boiler and the feedwater and coal feeding equipment. When the frequency regulation response subsystem receives a long-term, large-amplitude frequency regulation command, it sets the overshoot amount based on the load command to regulate the amount of water and coal entering the boiler.

[0011] In this invention, the composite energy storage subsystem includes a first battery for participating in short-term high-rate grid frequency regulation commands, i.e., primary frequency regulation, and a second battery for participating in long-term low-rate grid frequency regulation commands, i.e., secondary frequency regulation.

[0012] The composite energy storage subsystem also includes a first battery, a second battery, a DC / DC converter, a DC / AC inverter rectifier, and a BESS controller. The first battery and the second battery are each connected in series with a DC / DC converter. The output terminals of the two DC / DC converters are connected to the DC / AC inverter rectifier. The DC / AC inverter rectifier is connected to the high-voltage station service transformer, which is connected between the generator and the main transformer. One end of the BESS controller is connected to the load, the DC / AC inverter rectifier, the first battery, the second battery, and each DC / DC converter. The other end of the BESS controller is connected to the frequency regulation response subsystem.

[0013] In this invention, the condensate throttling frequency regulation response subsystem includes a condensate throttling response module for responding according to the subsystem's capabilities, a low-pressure heater bypass valve for regulating the amount of condensate entering the low-pressure heater, and a connecting piping system. The condensate throttling response module is connected to the low-pressure heater bypass valve, one end of which is connected between the low-pressure heater and the condensate pump, and the other end is connected to the boiler feedwater equipment. The condensate throttling frequency regulation response subsystem regulates the amount of condensate entering the low-pressure heater by controlling the opening of the low-pressure heater bypass valve, thereby indirectly regulating the turbine's steam extraction rate.

[0014] In this invention, the frequency regulation response subsystem participates in the frequency regulation response in conjunction with the received frequency regulation command, the unit's actual output control composite energy storage subsystem, the condensate throttling frequency regulation response subsystem, the boiler overshoot control subsystem, and the turbine main steam regulating valve, including participating in the primary frequency regulation mode and participating in the secondary frequency regulation mode.

[0015] Furthermore, the frequency regulation response subsystem, based on the received frequency regulation command, the actual unit output control composite energy storage subsystem, the condensate throttling frequency regulation response subsystem, the boiler overshoot control subsystem, and the turbine main steam regulating valve, jointly participates in the frequency regulation response, including jointly participating in the primary frequency regulation mode. The specific details are as follows:

[0016] The frequency regulation response subsystem sends instructions to the BESS controller of the composite energy storage subsystem. The BESS controller calculates the power setpoint of the composite energy storage subsystem based on the state of charge of the first battery and feeds the setpoint back to the frequency regulation response subsystem.

[0017] The frequency regulation response subsystem feeds back the difference between the primary frequency regulation response demand command and the set value of the first battery energy storage system to the condensate throttling response module; the condensate throttling response module adjusts the condensate flow rate according to key operating parameters, thereby controlling the amount of steam entering the low-pressure heater and participating in the primary frequency regulation response.

[0018] When the primary frequency regulation demand exceeds the frequency regulation response capacity of the composite energy storage subsystem and the condensate throttling response module, if it is a load reduction demand, the primary frequency regulation response demand is met by reducing the opening of the main steam control valve; if it is a load increase demand, a primary frequency regulation assessment fee will be incurred.

[0019] Furthermore, the frequency regulation response subsystem, based on the received frequency regulation command, the actual unit output control composite energy storage subsystem, the condensate throttling frequency regulation response subsystem, the boiler overshoot control subsystem, and the turbine main steam regulating valve, jointly participates in the frequency regulation response, including jointly participating in the secondary frequency regulation mode. The specific details are as follows:

[0020] The frequency regulation response subsystem generates a load demand command based on the grid secondary frequency regulation command and the actual load of the unit, and sends the load demand command to the BESS controller of the composite energy storage subsystem. The BESS controller calculates the power setpoint of the composite energy storage subsystem in conjunction with the state of charge of the second battery, and feeds the setpoint back to the frequency regulation response subsystem.

[0021] The frequency regulation response subsystem feeds back the difference between the secondary frequency regulation command and the set value of the second battery energy storage system to the condensate throttling response module; the condensate throttling response module adjusts the condensate flow rate according to key operating parameters, thereby controlling the amount of steam entering the low-pressure heater and participating in the response.

[0022] When the secondary frequency regulation command exceeds the capacity of the composite energy storage subsystem and the condensate throttling response module, if it is a load reduction requirement, the main steam control valve opening will be reduced to meet the requirement; if it is a load increase requirement, a secondary frequency regulation assessment fee will be incurred.

[0023] When the frequency regulation response subsystem receives a frequency regulation command that is greater than 50% of the rated power of the composite energy storage system for two consecutive minutes, it will send a secondary frequency regulation command to the boiler overshoot control subsystem. The boiler overshoot control subsystem will add an overshoot amount on the basis of the secondary frequency regulation command to control the amount of water and coal entering the boiler and overshoot the boiler load of the thermal power unit.

[0024] As a preferred embodiment, the first battery is a carbon-based capacitor battery, and the second battery is a lithium iron phosphate battery.

[0025] The combined thermal power and energy storage frequency regulation system and control method provided by this invention have at least the following advantages compared to the prior art:

[0026] 1) Compared with the traditional frequency regulation response method of thermal power units, the thermal power-storage combined frequency regulation system of the present invention combines composite energy storage, condensate frequency regulation and boiler overshoot, which can realize the full opening operation of the main steam regulating valve of thermal power unit, reduce valve throttling loss, and achieve coal saving and carbon reduction.

[0027] 2) The combined fire and energy storage frequency regulation system of the present invention integrates the advantages of high rate and long life of carbon-based capacitors and high energy density and low cost of lithium iron phosphate batteries. Through the composite energy storage subsystem, it enables different types of batteries to participate in different types of frequency regulation command requirements.

[0028] 3) This invention combines condensate frequency regulation and boiler overshoot, which can meet the grid frequency regulation requirements to the greatest extent while also optimizing the capacity configuration and service life of the composite energy storage subsystem. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a conventional frequency regulation system for existing thermal power units;

[0030] Figure 2 This is a schematic diagram of the structure of a conventional combined thermal power and energy storage frequency regulation system.

[0031] Figure 3 This is a schematic diagram of the combined thermal and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot in the embodiment. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0033] Example

[0034] This invention relates to a combined thermal power and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot. This system improves upon the traditional method of thermal power units participating in frequency regulation response through load adjustment via main steam control valve throttling. The system includes a composite energy storage subsystem, a condensate throttling frequency regulation response subsystem, a boiler overshoot control subsystem, a frequency regulation response subsystem, a condensate pump, a condenser, and a low-pressure heat exchanger (low-pressure heater). Specifically:

[0035] The composite energy storage subsystem includes: carbon-based capacitor batteries, lithium iron phosphate batteries, DC / DC converters, DC / AC inverters and rectifiers, and BESS controllers. Among them, carbon-based capacitor batteries are characterized by high power density, long cycle life, and high unit cost, and are mainly responsible for participating in short-term high-rate grid frequency regulation commands (primarily primary frequency regulation); lithium iron phosphate batteries are characterized by low power density, high capacity density, and low unit cost, and are mainly responsible for participating in long-term low-rate grid frequency regulation commands (primarily secondary frequency regulation). Figure 3 As shown, each of the carbon-based capacitor battery and the lithium iron phosphate battery is connected in series with a DC / DC converter. The outputs of the two DC / DC converters are connected to a DC / AC inverter rectifier, which is then connected to the high-voltage plant transformer. The high-voltage plant transformer is connected between the generator and the main transformer. The BESS controller is connected to the load, the DC / AC inverter rectifier, the carbon-based capacitor battery, the lithium iron phosphate battery, and each DC / DC converter to control the operation of each device. The other end of the BESS controller is connected to the frequency response subsystem.

[0036] The condensate throttling frequency regulation response subsystem mainly includes: a condensate throttling response module, a low-pressure heater bypass valve and its connecting piping system, etc., and is mainly responsible for assisting in primary and secondary frequency regulation responses; that is, when the composite energy storage subsystem cannot meet the grid frequency regulation response requirements due to battery capacity or power configuration limitations, the condensate throttling frequency regulation response subsystem participates in auxiliary regulation. Figure 3 As shown, the boiler is connected to the steam turbine via the main steam regulating valve. The steam turbine is connected to the low-pressure heat exchanger. One end of the condenser is connected to the steam turbine, and the other end is connected to the low-pressure heat exchanger via the condensate pump. The other end of the low-pressure heat exchanger is connected to the boiler feedwater equipment. The condensate throttling response module is connected to the low-pressure heater bypass valve and is used to respond according to the capability of the condensate throttling frequency regulation subsystem. One end of the low-pressure heater bypass valve is connected between the low-pressure heat exchanger and the condensate pump, and the other end is connected to the boiler feedwater equipment.

[0037] According to the above design, the main working principle of the condensate throttling frequency regulation response subsystem is as follows: by controlling the opening of the low-pressure heater bypass valve, the amount of condensate entering the low-pressure heater is adjusted, thereby indirectly regulating the turbine extraction steam rate and achieving the purpose of adjusting the turbine output. Specifically, when it is necessary to reduce the turbine output, the opening of the low-pressure heater bypass valve is reduced, increasing the condensate inlet flow to the low-pressure heater. In order to maintain the condensate outlet temperature of the low-pressure heater, the system will automatically increase the turbine extraction steam rate, thus reducing the turbine output.

[0038] The generator is equipped with water supply and coal supply equipment for power generation. Regulating valves are installed between the boiler and the water supply and coal supply equipment, and the boiler overshoot control subsystem is connected to each regulating valve. The function of the boiler overshoot control subsystem is as follows: when the frequency regulation response subsystem receives a frequency regulation command exceeding 50% of the rated power of the composite energy storage system for two consecutive minutes, the boiler overshoot control subsystem will set a certain overshoot based on the load command to regulate the amount of water and coal entering the boiler. Through the boiler overshoot control subsystem, on the one hand, the boiler load response time can be shortened, reducing the capacity configuration requirements of the composite energy storage subsystem; on the other hand, by setting a reasonable overshoot, the composite energy storage subsystem can avoid long-term unidirectional load regulation (i.e., long-term charging or discharging) during long-term, large-amplitude frequency regulation responses, and also avoid deep charging and discharging, maintaining the energy storage system at a reasonable state of charge, which is beneficial to the lifespan of the energy storage system.

[0039] The frequency regulation response subsystem, as the control module of the entire frequency regulation response system, participates in the frequency regulation response in conjunction with the received frequency regulation commands, the actual unit output control composite energy storage subsystem, the condensate throttling frequency regulation response subsystem, the boiler overshoot control subsystem, and the turbine main steam regulating valve. Throughout the frequency regulation response process, the main steam regulating valve of the thermal power unit is kept fully open as much as possible to achieve coal saving and carbon reduction. Details are as follows:

[0040] (1) For primary frequency regulation, the frequency regulation response subsystem sends instructions to the BESS controller of the composite energy storage subsystem. The BESS controller calculates the power setpoint of the composite energy storage subsystem based on the state of charge of the carbon-based capacitor battery and feeds the setpoint back to the frequency regulation response subsystem. The frequency regulation response subsystem feeds back the difference between the primary frequency regulation response demand instruction and the setpoint of the carbon-based capacitor energy storage system to the condensate throttling response module. The condensate throttling response module then adjusts the condensate flow rate appropriately based on key operating parameters such as condensate flow rate and condensate temperature, thereby controlling the amount of steam entering the low-pressure heater and participating in the primary frequency regulation response. The boiler overshoot control subsystem does not participate in the primary frequency regulation response. When the primary frequency regulation demand exceeds the frequency regulation response capacity of the composite energy storage subsystem and the condensate throttling response module, if it is a load reduction demand, the primary frequency regulation response demand can be further met by reducing the opening of the main steam regulating valve; if it is a load increase demand, a certain primary frequency regulation assessment fee will be incurred.

[0041] (2) For secondary frequency regulation, the frequency regulation response subsystem generates a load demand command based on the secondary frequency regulation command of the power grid and the actual load of the unit, and sends the load demand command to the BESS controller of the composite energy storage subsystem. The BESS controller calculates the power setpoint of the composite energy storage subsystem in conjunction with the state of charge of the lithium iron phosphate battery, and feeds the setpoint back to the frequency regulation response subsystem. The frequency regulation response subsystem feeds back the difference between the secondary frequency regulation command and the setpoint of the lithium iron phosphate battery energy storage system to the condensate throttling response module. The condensate throttling response module then adjusts the condensate flow rate appropriately based on key operating parameters such as condensate flow rate and condensate temperature, thereby controlling the amount of steam entering the low-pressure heater and participating in the response. When the secondary frequency regulation command exceeds the frequency regulation response capacity of the composite energy storage subsystem and the condensate throttling response, if it is a load reduction demand, the demand can be further met by reducing the opening of the main steam regulating valve; if it is a load increase demand, a certain secondary frequency regulation assessment fee will be incurred. Furthermore, when the frequency regulation response subsystem receives frequency regulation commands exceeding 50% of the rated power of the composite energy storage system for two consecutive minutes, it will issue a secondary frequency regulation command to the boiler overshoot control subsystem. The boiler overshoot control subsystem will then add a certain overshoot amount to the secondary frequency regulation command, controlling the amount of water and coal entering the boiler to overshoot the boiler load of the thermal power unit. By setting a reasonable overshoot amount, the composite energy storage subsystem can avoid prolonged unidirectional load regulation (i.e., prolonged charging or discharging) during long-term, large-amplitude frequency regulation responses, and also avoid deep charging and discharging, maintaining the energy storage system at a reasonable state of charge and extending its lifespan.

[0042] Compared with traditional frequency regulation response methods for thermal power units, the thermal power-storage combined frequency regulation system of this invention enables the main steam regulating valve of the thermal power unit to operate with full opening, reducing valve throttling losses and achieving coal saving and carbon reduction. In addition, the thermal power-storage combined frequency regulation system of this invention also combines the advantages of high rate and long life of carbon-based capacitors and high energy density and low cost of lithium iron phosphate batteries. Through the composite energy storage subsystem, different types of batteries can participate in different types of frequency regulation command requirements. Furthermore, by combining condensate frequency regulation and boiler overshoot, it maximizes the satisfaction of grid frequency regulation requirements while optimizing the capacity configuration and service life of the composite energy storage subsystem.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A combined thermal power and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot, used to improve the load regulation mode of thermal power units participating in frequency regulation response through main steam control valve throttling. The boiler is connected to the steam turbine through the main steam control valve, the steam turbine is connected to the low-pressure heat exchanger, one end of the condenser is connected to the steam turbine, and the other end is connected to the low-pressure heat exchanger through a condensate pump. The other end of the low-pressure heat exchanger is connected to the boiler feedwater equipment. Its features include... The system includes: A composite energy storage subsystem is used to enable different types of batteries to participate in different types of frequency regulation commands. The condensate throttling frequency regulation response subsystem is used to participate in auxiliary regulation when the composite energy storage subsystem cannot meet the grid frequency regulation response requirements; The frequency regulation response subsystem is used to control the composite energy storage subsystem, condensate throttling frequency regulation response subsystem, boiler overshoot control subsystem, and turbine main steam regulating valve in accordance with the received frequency regulation command and the actual output of the unit. The boiler overshoot control subsystem connects the regulating valves between the boiler and the water supply equipment and coal supply equipment. When the frequency regulation response subsystem receives a long-term, large-amplitude frequency regulation command, it sets the overshoot amount based on the load command to regulate the amount of water and coal entering the boiler. The frequency regulation response subsystem participates in the frequency regulation response in accordance with the received frequency regulation command, the actual output control composite energy storage subsystem of the unit, the condensate throttling frequency regulation response subsystem, the boiler overshoot control subsystem, and the turbine main steam regulating valve, including participating in the primary frequency regulation mode and participating in the secondary frequency regulation mode. The frequency regulation response subsystem, based on the received frequency regulation command, the actual unit output control composite energy storage subsystem, the condensate throttling frequency regulation response subsystem, the boiler overshoot control subsystem, and the turbine main steam regulating valve, jointly participates in the frequency regulation response, including jointly participating in the primary frequency regulation mode. The specific details are as follows: The frequency regulation response subsystem sends instructions to the BESS controller of the composite energy storage subsystem. The BESS controller calculates the power setpoint of the composite energy storage subsystem based on the state of charge of the first battery and feeds the setpoint back to the frequency regulation response subsystem. The frequency regulation response subsystem feeds back the difference between the primary frequency regulation response demand command and the set value of the first battery energy storage system to the condensate throttling response module; the condensate throttling response module adjusts the condensate flow rate according to key operating parameters, thereby controlling the amount of steam entering the low-pressure heater and participating in the primary frequency regulation response. When the primary frequency regulation demand exceeds the frequency regulation response capacity of the composite energy storage subsystem and the condensate throttling response module, if it is a load reduction demand, the primary frequency regulation response demand is met by reducing the opening of the main steam control valve; if it is a load increase demand, a primary frequency regulation assessment fee will be incurred. The frequency regulation response subsystem, based on the received frequency regulation command, the actual unit output control composite energy storage subsystem, the condensate throttling frequency regulation response subsystem, the boiler overshoot control subsystem, and the turbine main steam regulating valve, jointly participates in the frequency regulation response, including jointly participating in the secondary frequency regulation mode. The specific details are as follows: The frequency regulation response subsystem generates a load demand command based on the grid secondary frequency regulation command and the actual load of the unit, and sends the load demand command to the BESS controller of the composite energy storage subsystem. The BESS controller calculates the power setpoint of the composite energy storage subsystem in conjunction with the state of charge of the second battery, and feeds the setpoint back to the frequency regulation response subsystem. The frequency regulation response subsystem feeds back the difference between the secondary frequency regulation command and the set value of the second battery energy storage system to the condensate throttling response module; the condensate throttling response module adjusts the condensate flow rate according to key operating parameters, thereby controlling the amount of steam entering the low-pressure heater and participating in the response. When the secondary frequency regulation command exceeds the capacity of the composite energy storage subsystem and the condensate throttling response module, if it is a load reduction requirement, the main steam control valve opening will be reduced to meet the requirement; if it is a load increase requirement, a secondary frequency regulation assessment fee will be incurred. When the frequency regulation response subsystem receives a frequency regulation command that is greater than 50% of the rated power of the composite energy storage system for two consecutive minutes, it will send a secondary frequency regulation command to the boiler overshoot control subsystem. The boiler overshoot control subsystem will add an overshoot amount on the basis of the secondary frequency regulation command to control the amount of water and coal entering the boiler and overshoot the boiler load of the thermal power unit.

2. The combined thermal and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot as described in claim 1, characterized in that, The composite energy storage subsystem includes a first battery for participating in short-term high-rate grid frequency regulation commands, i.e., primary frequency regulation, and a second battery for participating in long-term low-rate grid frequency regulation commands, i.e., secondary frequency regulation.

3. The combined thermal and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot as described in claim 2, is characterized in that, The composite energy storage subsystem also includes a first battery, a second battery, a DC / DC converter, a DC / AC inverter rectifier, and a BESS controller. The first battery and the second battery are each connected in series with a DC / DC converter. The output terminals of the two DC / DC converters are connected to the DC / AC inverter rectifier. The DC / AC inverter rectifier is connected to the high-voltage station service transformer, which is connected between the generator and the main transformer. One end of the BESS controller is connected to the load, the DC / AC inverter rectifier, the first battery, the second battery, and each DC / DC converter. The other end of the BESS controller is connected to the frequency regulation response subsystem.

4. The combined thermal and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot as described in claim 3, is characterized in that, The condensate throttling frequency regulation response subsystem includes a condensate throttling response module for responding according to the subsystem's capabilities, a low-pressure heater bypass valve for regulating the amount of condensate entering the low-pressure heater, and connecting piping. The condensate throttling response module is connected to the low-pressure heater bypass valve, one end of which is connected between the low-pressure heater and the condensate pump, and the other end is connected to the boiler feedwater equipment. The condensate throttling frequency regulation response subsystem regulates the amount of condensate entering the low-pressure heater by controlling the opening of the low-pressure heater bypass valve, thereby indirectly regulating the turbine's steam extraction rate.

5. The combined thermal and energy storage frequency regulation system based on composite energy storage, condensate frequency regulation, and boiler overshoot as described in claim 2, characterized in that, The first battery is a carbon-based capacitor battery, and the second battery is a lithium iron phosphate battery.

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