Composite energy storage power supply system for grid peak shaving and frequency modulation and its regulation method

Abstract

The application provides a composite energy storage power supply system for grid peak shaving and frequency modulation, comprising a renewable energy power generation device; a battery energy storage device, a first input end of the battery energy storage device being connected with a power output end of the renewable energy power generation device through a DC / DC converter; a first DC / AC converter, a power output end of the battery energy storage device being connected with a common AC bus through the first DC / AC converter; a second DC / AC converter, the power output end of the renewable energy power generation device being connected with the common AC bus through the second DC / AC converter; a solar thermal power generation device, a power output end of the solar thermal power generation device being connected with the common AC bus through an AC / AC converter; and a heat storage device, the heat storage device being connected with the solar thermal power generation device and being capable of storing and releasing heat with the solar power generation device. The composite energy storage power supply system provided by the application can take into account stability, reliability, economy and environmental protection when used for grid peak shaving and frequency modulation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of renewable energy power generation, in particular to a composite energy storage power supply system for grid peak shaving and frequency modulation and a regulation method thereof. BACKGROUND

[0002] Renewable energy power generation such as wind power and photovoltaic power has the characteristics of volatility, randomness and non-schedulability, which has caused certain impact on the safe and stable operation of the power grid, and the phenomenon of wind curtailment and light curtailment has become increasingly prominent, which has seriously affected the economic benefits. At present, the use of traditional thermal power units for peak shaving and frequency modulation can stabilize the fluctuations to a certain extent, but as the proportion of thermal power gradually decreases and the installed capacity of renewable energy increases, the use of thermal power units alone will not be able to meet the demand for peak shaving and frequency modulation, and the participation of thermal power units in frequency modulation will also have a great impact on their own service life. Large-scale energy storage technology can store excess energy and release it when needed, has the characteristics of good dynamic response, long service life and high reliability, can improve the output quality of renewable energy power generation such as wind power and photovoltaic power, solve the problem of wind curtailment and light curtailment, and improve the economy of the power grid.

[0003] At present, the energy storage technologies that can be used for grid peak shaving and frequency modulation include pumped storage, compressed air energy storage, electrochemical energy storage and heat storage. For a single energy storage method, in electrochemical energy storage, battery energy storage has a fast response speed and is suitable for suppressing rapid output fluctuations in a short time range. However, due to the high price of battery systems, the operation and maintenance cost of large-capacity battery systems is higher, and it is not suitable for suppressing large-scale output fluctuations. Pumped storage, compressed air energy storage and molten salt energy storage are suitable for large-scale energy storage, but pumped storage has too high requirements for site selection, and the development of large and super large key equipment for compressed air energy storage is difficult. Heat storage has the advantages of large capacity, environmental friendliness, high safety, simple site selection, friendliness to the power grid and obvious energy storage benefits, and as the capacity of heat storage increases, the cost of heat storage will further decrease. Heat storage has a slower response speed compared with battery energy storage and is suitable for suppressing large fluctuations in a long time range.

[0004] A Chinese patent document with publication number CN108173274A and the title of a multi-element energy storage peak shaving and frequency modulation system based on pumped storage power station and hydropower station discloses a multi-element energy storage peak shaving and frequency modulation system based on pumped storage power station and hydropower station, which includes a hydraulic power generation module, the hydraulic power generation module is connected with the input end of a main transformer, transformer three and an alternating current switch device through wires, the output end of the main transformer is connected with a power grid, transformer three is connected with a flywheel energy storage group module, the alternating current switch device is connected with a transformer four, the transformer four is connected with a battery energy storage group module, and the hydraulic power generation module, the flywheel energy storage group module and the battery energy storage group module are connected with a peak shaving and frequency modulation coordination control center. The peak shaving and frequency modulation system disclosed in the Chinese patent document uses pumped storage, which has high requirements for the selection of site environment, high cost, low safety and poor stability.

[0005] Therefore, it is necessary to improve the existing energy storage technology for grid peak shaving and frequency modulation. SUMMARY

[0006] In view of the defects in the prior art, the purpose of the present application is to provide a composite energy storage power supply system for grid peak shaving and frequency modulation and a regulation method thereof.

[0007] The composite energy storage power supply system for grid peak shaving and frequency modulation comprises:

[0008] a renewable energy power generation device;

[0009] a battery energy storage device, a first input end of the battery energy storage device being connected with a power output end of the renewable energy power generation device through a DC / DC converter;

[0010] a first DC / AC converter, a power output end of the battery energy storage device being connected with a common AC bus through the first DC / AC converter;

[0011] a second DC / AC converter, a power output end of the renewable energy power generation device being connected with the common AC bus through the second DC / AC converter;

[0012] a solar thermal power generation device, a power output end of the solar thermal power generation device being connected with the common AC bus through an AC / AC converter;

[0013] a heat storage device, the heat storage device being connected with the solar thermal power generation device and being capable of storing and releasing heat with the solar power generation device.

[0014] Preferably, the battery energy storage device further comprises a second input end of the battery energy storage device, the second input end of the battery energy storage device being connected with the power output end of the solar thermal power generation device through an AC / DC converter.

[0015] Preferably, a central management device, a first input end and a second input end of the central management device being connected with an output end of the first DC / AC converter and an output end of the second DC / AC converter respectively, an output end of the central management device being connected with the common AC bus, the central management device being in communication connection with an external grid dispatching system.

[0016] Preferably, the renewable energy power generation device comprises any one of a wind power generation system, a solar light power generation system, a solar thermal power generation device and other renewable energy power generation devices with fluctuating output.

[0017] Preferably, the solar thermal power generation device is a power generation device for converting heat energy into electric energy.

[0018] Preferably, a local coordination processing controller is in communication with the battery energy storage device and the thermal storage device and the central processing device, respectively, and is capable of receiving instructions from the central processing device and optimizing the output of the battery energy storage device and the thermal storage device according to the instructions and the state of charge of the battery energy storage device and the thermal storage device.

[0019] Preferably, an environment / load prediction device is in communication with the central management device, generates prediction data including external environment and load changes of the public AC bus, and sends the prediction data to the central management device.

[0020] Preferably, the battery energy storage device further comprises:

[0021] An energy module comprising heat dissipation, measurement and signal loop to provide energy storage;

[0022] A control module providing a communication interface with the outside, monitoring the state of the energy module and PCS, scheduling the setting of charge and discharge power according to the instructions from the local coordination processing controller, and controlling the operation of the battery energy storage device;

[0023] A power module responding to the instructions generated by the control module to control the charge and discharge actions of the energy module and provide a grid-connected interface of the composite energy storage power supply system.

[0024] Preferably, the composite energy storage power supply system further comprises:

[0025] An electric energy conversion device, the inlet end of which is connected to the power output end of the renewable energy power generation device, and the outlet end of which is connected to the thermal storage device, for converting the electric energy generated by the renewable energy power generation device into thermal energy stored in the thermal storage device.

[0026] Preferably, the thermal storage device comprises:

[0027] A tank, at least one, which is capable of containing a plurality of thermal storage units inside, and the thermal storage units contain thermal storage working medium;

[0028] A bypass control system capable of bypass connecting the working medium outlet of the thermal storage unit and the working medium inlet of the thermal storage unit for stabilizing the outlet state of the thermal storage working medium.

[0029] The present application further provides a regulation and control method for a composite energy storage power supply system for grid peak shaving and frequency modulation, which regulates and controls the composite energy storage power supply system as described above, comprising the following steps:

[0030] a total power demand calculation step, in which the central management device integrates grid peak shaving and frequency modulation demand scheduling instructions from an external grid dispatching system, local photovoltaic power generation and solar thermal power generation state information from the environment / load prediction device, and predicted data of external environment and load changes of the public AC bus to give total power demand information of the composite energy storage system;

[0031] a heat storage device power output step, in which heat storage device power output information is output to the central processing device according to the total power demand information of the composite energy storage system and the state of charge of the heat storage device;

[0032] a central management device feedback step, in which a power difference is calculated and output to the battery energy storage device according to the heat storage device power output information;

[0033] a battery energy storage device system power output step, in which battery energy storage device power output information is output to the central processing device according to the power difference and the state of charge of the battery energy storage device.

[0034] Compared with the prior art, the application has the following beneficial effects:

[0035] 1. The composite energy storage system coordination processing control method formed by the battery energy storage device and the heat storage device can perform real-time peak shaving and frequency modulation on the renewable energy power generation system, the battery energy storage device responds quickly and can suppress rapid fluctuations of the renewable energy power generation system within a short period of time, the heat storage device has large capacity and can suppress large fluctuations of the renewable energy power generation system within a long period of time. At the same time, the battery energy storage device can also suppress rapid fluctuations within a short period of time that exceed the adjustment range of the heat storage device, optimize the output target of the battery energy storage and the heat storage, and make the composite energy storage system work within a reasonable range, thereby stabilizing the output of the local renewable energy power generation system and the output of other renewable energy power generation systems within the local area network.

[0036] 2. When the solar energy fluctuates and is unstable, the heat storage device can provide a stable heat source for the solar thermal power generation device. When the solar energy is excessive, the excess heat is stored in the heat storage device, thereby improving the energy utilization rate.

[0037] 3. The renewable energy power generation device cooperates with the battery energy storage system, the battery energy storage system suppresses the power generation fluctuations of the renewable energy power generation device through the charging and discharging process; the renewable energy power generation device cooperates with the heat storage device, and the excess power generated by the renewable energy power generation system that cannot be grid-connected is converted into heat energy by the electrothermal conversion device and stored in the heat storage device, thereby improving the stability of system operation, saving energy, and improving the energy utilization rate. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a structural schematic diagram of a composite energy storage power supply system for grid peak shaving and frequency modulation of the application;

[0039] Figure 2 is a structural schematic diagram of a composite energy storage power supply system for grid peak shaving and frequency modulation of the application;

[0040] Figure 3 is a structural schematic diagram of a composite energy storage power supply system for grid peak shaving and frequency modulation of the application based on a tower type solar energy Brayton cycle gas turbine power generation system thermal chemical heat storage device;

[0041] Figure 4 is a structural schematic diagram of a composite energy storage power supply system for grid peak shaving and frequency modulation of the application based on a tower type solar energy Brayton cycle gas turbine power generation system heat storage device bypass control system;

[0042] Figure 5 is a structural schematic diagram of a composite energy storage power supply system for grid peak shaving and frequency modulation of the application using a wind power generation system, a solar photovoltaic power generation system and a tower type solar energy Brayton cycle gas turbine power generation system;

[0043] Figure 6 is a control method schematic diagram of a composite energy storage power supply system for grid peak shaving and frequency modulation provided by the application.

[0044] Explanation of reference signs

[0045] Renewable energy power generation device 1; battery energy storage device 2; heat storage device 3; local coordination processing controller 5; environment / load prediction device 6; first input end of battery energy storage device 7; DC / DC converter 8; first DC / AC converter 9; public AC bus 10; second DC / AC converter 11; solar thermal power generation device 12; AC / AC converter 13; second input end of battery energy storage device 14; AC / DC converter 15; electric heating conversion device 16; air inlet 17; air outlet 18; electric heater 19; central management device 20; power grid 21; electric switch 22; heat storage unit 23; bypass control system 24; bypass 25; valve 26; wind power generation system 27; solar photovoltaic power generation system 28; mirror field 29; air heat absorber 30; bypass valve 32; regenerator 33; air compressor 34; turbine 35; generator 36; waste heat utilization device 37; AC / AC converter 38; tower type solar energy Brayton cycle gas turbine power generation system 39; DC / AC converter 40. DETAILED DESCRIPTION

[0046] The application will be described in detail below with specific examples. The following examples will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the application. These are within the scope of the present application.

[0047] As Figure 1 The application provides a composite energy storage power supply system for grid peak shaving and frequency modulation, which comprises a renewable energy power generation device 1, a battery energy storage device 2, a heat storage device 3, and a central management device 20. The first input end 7 of the battery energy storage device 2 is connected to the power output end of the renewable energy power generation device 1 through a DC / DC converter 8. The power output end of the battery energy storage device 1 is connected to a public AC bus 10 through a first DC / AC converter 9. The power output end of the renewable energy power generation device 1 is connected to the public AC bus 10 through a second DC / AC converter 11. The composite energy storage power supply system further comprises a solar thermal power generation device 12, the power output end of which is connected to the public AC bus 10 through an AC / AC converter 13. The heat storage device 3 is connected to the solar thermal power generation device 12 and can store and release heat with the solar thermal power generation device 12. The composite energy storage power supply system for grid peak shaving and frequency modulation couples the battery energy storage device 2 and the heat storage device 3, uses the composite energy storage power supply system composed of the battery energy storage device 2 and the heat storage device 3 to coordinate output regulation, and regulates the renewable energy power generation device 1 in real time. Specifically, the battery energy storage device 2 responds quickly and mainly suppresses the rapid fluctuations of the renewable energy power generation device 1 in a short period of time. The heat storage device 3 has a large capacity and is mainly used to suppress the large fluctuations of the renewable energy power generation device 1 in a long period of time. Meanwhile, the heat storage device 3 can release heat to promote the solar thermal power generation device to generate electricity for the battery energy storage device 2, suppress the rapid fluctuations of the heat storage device 3 in a short period of time, optimize the output target of the battery energy storage device 2 and the heat storage device 3, and make the composite energy storage system work in a reasonable range, stabilize the output of the local renewable energy power generation device 1 and the output of other renewable energy power generation systems in the local area network. The regulation method combines the characteristics of the large capacity of the heat storage device and the quick response, accurate and reliable regulation of the battery energy storage device, reduces the occupation of the expensive battery capacity of the battery energy storage device, saves costs, and improves economic efficiency.

[0048] As a preferred embodiment of the present application, the renewable energy power generation device 1 includes any one of a wind power generation system, a solar photovoltaic power generation system, a solar thermal power generation device and other renewable energy power generation devices with fluctuating output, and the battery energy storage device 2 further includes a second input end 14 of the battery energy storage device, which is connected with the power output end of the solar thermal power generation device 12 through an AC / DC converter 15. The solar thermal power generation device 12 cooperates with the heat storage device 3. When the solar energy is unstable, the heat storage device 3 can provide a stable heat source for the solar thermal power generation device 12. When the solar energy is excessive, the excess heat is stored in the heat storage device 3. The wind power generation system, the solar photovoltaic power generation system and other renewable energy power generation systems cooperate with the battery energy storage device 2. The battery energy storage device 2 smoothes the power generation fluctuation of the wind power generation system, the solar photovoltaic power generation system and other renewable energy power generation systems through the charging and discharging process. The battery energy storage device 2 cooperates with the heat storage device 3. The excess power generated by the wind power generation system, the solar photovoltaic power generation system and other renewable energy power generation systems, which cannot be grid-connected, is converted into heat energy by the electric-thermal conversion device 16 and stored in the heat storage device 3. When the battery energy storage device 2 is insufficient to smooth the rapid fluctuation in a short time, the heat storage device 3 releases heat to drive the solar thermal power generation device 12 to generate power. Part of the power is charged to the battery energy storage device 2 through the AC / DC converter 15 until the battery energy storage device 2 is sufficient to smooth the rapid fluctuation in a short time.

[0049] As a preferred embodiment of the present application, the central management device 20 is further included, which is in communication connection with an external grid dispatching system. The first input end and the second input end of the central management device 20 are connected with the output end of the first DC / AC converter 9 and the output end of the second DC / AC converter 11 respectively. The output end of the central management device 20 is connected with the public AC bus 10. The central management device 20 can give peak shaving and frequency modulation instructions based on comprehensive information.

[0050] As a preferred embodiment of the present application, the local coordination processing controller 5 is further included, which is in communication connection with the battery energy storage device 2, the heat storage device 3 and the central processing device 20 respectively. The local coordination processing controller 5 can accept instructions from the central processing device 20. The local coordination processing controller 5 can optimize the output of the battery energy storage device 2 and the heat storage device 3 according to the instructions and the state of charge of the battery energy storage device 2 and the heat storage device 3.

[0051] As a preferred embodiment of the present application, the environmental / load prediction device 6 comprehensively predicts the changes of light, wind volume and alternating current load in a certain area and a certain period of time by comprehensively considering weather conditions, electricity demand and time period, and further predicts the change of electricity price and feeds back to the central management device 20. The central management device 20 further receives the information of local photovoltaic power generation and photo-thermal power generation and the information of grid peak shaving and frequency modulation demand, comprehensively considers the above information, forms a scheduling instruction and sends it to the local coordination processing controller 5. The battery energy storage device 2 and the heat storage device 3 cooperatively output according to the instruction to complete the peak shaving and frequency modulation process. At the same time, the central management device 20 actively reports the peak shaving and frequency modulation capacity of the local composite energy storage system to the grid dispatching center to stabilize the local area network power output.

[0052] As a preferred embodiment, the battery energy storage device 2 comprises an energy module for providing energy storage capacity, including heat dissipation, measurement and signal loop inside the energy storage unit; a power module for controlling the charging and discharging actions of the battery energy storage unit in response to the instructions of the communication and control unit. At the same time, the grid-connected interface of the battery energy storage device 2 is provided to meet the requirements of grid-connected power quality, grid adaptability and fault protection function; a control module for providing a communication interface with the local area network and the grid, monitoring the state of the energy storage unit and the PCS, and controlling the operation of the battery energy storage device 2 according to the instruction of the local coordination processing controller 5 to set the charging and discharging power of the battery energy storage device 2.

[0053] As Figure 2 As a preferred embodiment of the present application, the central management device 20 receives the peak shaving and frequency modulation instruction, gives the total power demand Ps of the composite energy storage system and controls the output of the heat storage device 3. The heat storage device 3 actually outputs Phs based on the heat storage SOC feedback system 221 and feeds back to the central management device 20. The central management device 20 calculates the power difference and feeds back to the battery energy storage device 2 to control its output. The battery energy storage device 2 actually outputs Pbs based on the battery energy storage SOC feedback system 222 and feeds back the output information to the central management device 20 to form a closed-loop feedback system, complete the peak shaving and frequency modulation process, and improve the stability and reliability of the local area network.

[0054] As Figure 3 As a preferred embodiment of the present application, the central management device 20 receives the peak shaving and frequency modulation instruction, gives the total power demand Ps of the composite energy storage system and controls the output of the heat storage device 3. The heat storage device 3 actually outputs Phs based on the heat storage SOC feedback system 221 and feeds back to the central management device 20. The central management device 20 calculates the power difference and feeds back to the battery energy storage device 2 to control its output. The battery energy storage device 2 actually outputs Pbs based on the battery energy storage SOC feedback system 222 and feeds back the output information to the central management device 20 to form a closed-loop feedback system, complete the peak shaving and frequency modulation process, and improve the stability and reliability of the local area network. As a preferred embodiment of the present application, the composite energy storage power supply system based on the heat chemical heat storage device of the tower type solar Brayton cycle gas turbine power generation system comprises an air inlet 17, an air outlet 18, an electric heater 19 and a heat storage unit 23. When the composite energy storage power supply system provided by the present application is matched with the tower type solar Brayton cycle gas turbine power generation system, the electric heating conversion device adopts the electric heater 19. The air inlet 17 is arranged at the top of the tank body, the air outlet 18 is arranged at the bottom of the tank body, and the heat chemical heat storage units are distributed in the plurality of heat storage units 23 inside the tank body.

[0055] As a preferred embodiment, the local area network can set multiple heat storage tanks according to actual needs; the electric heating device converts the excess electric energy in the renewable energy power generation device 1 into heat energy and stores it in the heat storage device 3; because the hot gas has a smaller density than the normal temperature gas, the heated gas is easy to flow upward under the influence of buoyancy, and the hot gas will gradually and uniformly fill the tank from top to bottom by adopting the setting mode that the air inlet 17 is arranged at the top of the tank and the air outlet 18 is arranged at the bottom of the tank. The thermochemical heat storage is the heat storage mode with the largest heat storage density at present, can realize seasonal long-term storage and long-distance transportation, and can realize the upgrading of heat energy grade, the principle is to use reversible thermochemical reaction to realize the process of heat storage and heat release, and multiple heat storage units 23 can make the heat storage and heat release process more complete.

[0056] As a preferred embodiment, when the heat storage device 3 cooperates with the tower type solar Brayton cycle gas turbine power generation system, the medium flowing into the tank through the air inlet 17 is air, and the thermochemical heat storage medium is metal oxide. As the thermochemical heat storage medium, air is both the reactant of the heat storage / heat release process and the heat transfer medium, compared with other heat storage devices, the heat loss generated by heat exchange with the heat storage device is reduced, the heat storage efficiency is higher, and the metal oxide oxidation-reduction reaction has good cycle stability, can maintain good reaction kinetics and structural stability after multiple cycles, and can maintain stable operation for a long time after initial use.

[0057] As a preferred embodiment, as shown in Figure 4 The bypass control system 24 of the heat storage device of the tower type solar Brayton cycle gas turbine power generation system of the composite energy storage power supply system for grid peak regulation and frequency modulation provided by the application also includes a bypass 25 and a valve 26, the bypass control system 24 can bypass connect the working medium outlet of the heat storage unit 23 and the working medium inlet of the heat storage unit 23, and is used for stabilizing the outlet state of the working medium of the heat storage unit 23. In the bypass control system 24, the opening degree of the bypass valve 26 is changed to control and stabilize the outlet air temperature of the heat storage tank to meet the requirements of the gas turbine. When the heat storage tank is storing heat, the opening degree of the valve 26 is adjusted to be small, the high-temperature air mainly flows through the heat storage tank, and the high-temperature air heat energy is converted into chemical energy by chemical reaction and stored in the heat storage medium; after the heat storage tank is fully stored, the opening degree of the valve 26 is adjusted to be large, and the high-temperature air mainly flows to the downstream through the bypass except that a part of the hot air is used to maintain the temperature and state stability of the heat storage tank.

[0058] As shown in Figure 5The application provides a composite energy storage power supply system for grid peak shaving and frequency modulation, and the system is used for stabilizing local power generation system output, and the renewable energy power generation device comprises a wind power generation system 27, a solar photovoltaic power generation system 28 and a tower type solar energy Brayton cycle gas turbine power generation system 39. The battery energy storage device 2 is coupled with the heat storage device 3, when the output of the power generation system fluctuates and cannot reach the grid-connected power generation requirement, the central management device 20 collects signals and generates scheduling instructions, after the local coordination processing controller 5 receives the scheduling instructions, the battery energy storage device 2 and the heat storage device 3 are adjusted according to the regulation method to cooperatively adjust the charging and discharging and heat storage and release processes, so that the peak shaving and frequency modulation are realized, and the self power generation output is stabilized. The tower type solar energy Brayton cycle gas turbine power generation system comprises a mirror field 29, an air heat absorber 30, the heat storage device 3, a bypass valve 32, a regenerator 33, a compressor 34, a turbine 35, a generator 36, a waste heat utilization device 37 and an AC / AC converter 38. Ambient air enters the regenerator 33 after being pressurized by the compressor, is preheated, enters the air heat absorber 30 and is heated by the focused sunlight of the heliostat field 29, the high-temperature air after being heated enters the heat storage device 3, the heat storage device 3 absorbs or releases heat according to the system operation condition, if the air temperature is higher than the stable operation air temperature of the gas turbine, the heat storage device 3 absorbs the excess heat, if the air temperature is lower than the stable operation air temperature of the gas turbine, the heat storage device 3 releases heat, the stable high-temperature air enters the turbine for expansion and power generation, the turbine exhaust gas enters the waste heat utilization device after being cooled by the regenerator. The turbine 35 drives the generator to generate power and is connected with the public AC bus 10 through the AC / AC converter 38. The wind power generation system 27, the solar photovoltaic power generation system 28 and the battery energy storage device 2 are connected with the DC bus through the DC / DC converter 8, the DC bus is connected with the AC bus 10 through the DC / AC converter 40, the AC bus 10 is connected with the power grid and can be directly connected with the AC load, meanwhile, the DC bus is also connected with the electric heating device in the heat storage device 3. When the output of the wind power generation system 27 or the solar photovoltaic power generation system 28 is higher than the expected value, the excess electric energy is stored in the battery energy storage device or is converted into heat energy by the electric heating device and stored in the heat storage device 3, when the output of the wind power generation system 27 or the solar photovoltaic power generation system 28 is lower than the expected value, the battery energy storage device 2 is discharged to suppress the insufficient output of the solar photovoltaic power generation system or the heat storage device 3 releases heat to improve the output of the tower type solar energy Brayton cycle gas turbine power generation system to suppress the insufficient output of the wind power generation system 27 or the solar photovoltaic power generation system 28.When the battery energy storage device 2 is not sufficient to smooth the rapid fluctuations in the output for a short period of time, the heat storage device 3 releases heat to drive the solar thermal power generation device 12 to generate electricity, and part of the electricity is converted by the AC / DC converter 15 to charge the battery energy storage device 2 until the battery energy storage device 2 is sufficient to smooth the rapid fluctuations in the output for a short period of time.

[0059] As a preferred embodiment, the composite energy storage power supply system for grid peak shaving and frequency modulation provided by the present application is used to stabilize the output of other renewable energy power generation systems in the local area network. When the local wind power generation system 27, the photovoltaic power generation system 28, and the tower type solar energy Brayton cycle gas turbine power generation system output are stable, and the output of other renewable energy power generation devices in the local area network is unstable, the central management device 20 in the composite energy storage system for grid peak shaving and frequency modulation receives the dispatching instruction from the local area network and sends the dispatching instruction to the local coordination controller 5. The energy storage capacity of the battery energy storage device 2 and the heat storage device 3 after smoothing the fluctuations of the local power generation system is adjusted according to the regulation method, and the charging and discharging and heat storage and release processes are adjusted in coordination, so as to realize the local area network peak shaving and frequency modulation and stabilize the output of other renewable energy power generation systems in the local area network.

[0060] As a preferred embodiment, the composite energy storage power supply system for grid peak shaving and frequency modulation provided by the present application is used to stabilize the output of other renewable energy power generation systems in the local area network. When the local wind power generation system 27, the photovoltaic power generation system 28, and the tower type solar energy Brayton cycle gas turbine power generation system output are stable, and the output of other renewable energy power generation devices in the local area network is unstable, the central management device 20 in the composite energy storage system for grid peak shaving and frequency modulation receives the dispatching instruction from the local area network and sends the dispatching instruction to the local coordination controller 5. The energy storage capacity of the battery energy storage device 2 and the heat storage device 3 after smoothing the fluctuations of the local power generation system is adjusted according to the regulation method, and the charging and discharging and heat storage and release processes are adjusted in coordination, so as to realize the local area network peak shaving and frequency modulation and stabilize the output of other renewable energy power generation systems in the local area network.

[0061] As shown in Figure 6 The present application further provides a regulation method for the composite energy storage power supply system for grid peak shaving and frequency modulation, which can regulate the composite energy storage power supply system as described above, and includes the following steps:

[0062] The total power demand calculation step S1, the central management device integrates the power peak regulation and frequency regulation demand scheduling instruction from the external power grid scheduling system, the local photovoltaic power generation and photothermal power generation state information from the environment / load prediction device, and the prediction data of the external environment and the public AC bus load change, and gives the total power demand information of the composite energy storage system;

[0063] The heat storage device power output step S2, according to the total power demand information of the composite energy storage system and the state of charge of the heat storage device, outputs the heat storage device power output information to the central processing device;

[0064] The central management device feedback step S3, according to the heat storage device power output information, calculates the power difference and outputs to the battery energy storage device;

[0065] The battery energy storage device system power output step S4, according to the power difference and the state of charge of the battery energy storage device, outputs the battery energy storage device power output information to the central processing device.

[0066] Those skilled in the art know that, in addition to implementing the system provided by the present application and each device, module, unit thereof in a pure computer readable program code manner, the same function can also be realized by logically programming the method steps in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers and embedded microcontrollers. Therefore, the system provided by the present application and each device, module, unit thereof can be considered as a hardware component, and the devices, modules, units included therein for realizing various functions can also be considered as structures within the hardware component; the devices, modules, units for realizing various functions can also be considered as both software modules realizing methods and structures within hardware components.

[0067] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0068] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other without conflict.

Claims

1. A composite energy storage power supply system for power grid peak shaving and frequency regulation, characterized in that, include: Renewable energy power generation equipment; A battery energy storage device, wherein the first input terminal of the battery energy storage device is connected to the power output terminal of the renewable energy power generation device via a DC / DC converter; The first DC / AC converter is used to connect the power output terminal of the battery energy storage device to the common AC bus. The power output terminal of the renewable energy power generation device is connected to the common AC bus via the second DC / AC converter. A solar thermal power generation device, wherein the power output terminal of the solar thermal power generation device is connected to the common AC bus via an AC / AC converter; A thermal storage device is provided, which is connected to the solar thermal power generation device and can perform thermal storage and release with the solar thermal power generation device. An electrical energy conversion device is provided, with its inlet connected to the power output of the renewable energy power generation device and its outlet connected to the thermal storage device. This device converts the electrical energy generated by the renewable energy power generation device into the thermal energy stored in the thermal storage device. The battery energy storage device further includes a second input terminal, which is connected to the power output terminal of the solar thermal power generation device via an AC / DC converter. The battery energy storage device smooths out rapid fluctuations in the renewable energy power generation system over short periods, while the thermal storage device smooths out large fluctuations in the renewable energy power generation system over long periods. When the battery energy storage device's capacity is insufficient to mitigate rapid fluctuations in the renewable energy power generation system over a short period, the thermal storage device releases heat to heat the air medium. The heated, high-temperature air medium then drives the solar thermal power generation device to generate electricity. Part of this electricity is then used by the AC / DC converter to charge the battery energy storage device to a level sufficient to mitigate rapid fluctuations over a short period. The thermal storage device includes: a tank, at least one tank, the tank being open at both ends and capable of accommodating multiple thermal storage units, each thermal storage unit containing a thermochemical thermal storage medium. The thermal storage device further includes a bypass control system, which can bypass the outlet and inlet of the working fluid of the thermal storage unit to stabilize the outlet state of the working fluid. The working fluid is air. The solar thermal power generation device is a solar Brayton cycle power generation system.

2. The composite energy storage power supply system as described in claim 1, characterized in that, Also includes: A central management device is communicatively connected to an external power grid dispatching system. The first and second input terminals of the central management device are respectively connected to the output terminals of the first and second DC / AC converters. The output terminal of the central management device is connected to the common AC bus.

3. The composite energy storage power supply system as described in any one of claims 1 to 2, characterized in that: The renewable energy power generation device includes any one of wind power generation systems, solar photovoltaic power generation systems, solar thermal power generation devices, and other renewable energy power generation devices with fluctuating output.

4. The composite energy storage power supply system as described in claim 3, characterized in that: The solar thermal power generation device is a power generation device that converts thermal energy into electrical energy.

5. The composite energy storage power supply system as described in claim 2, characterized in that, Also includes: A local coordination processing controller is communicatively connected to the battery energy storage device, the thermal storage device, and the central management device, respectively. The local coordination processing controller can receive instructions from the central management device and optimize the processing of the battery energy storage device and the thermal storage device based on the instructions and the state of charge of the battery energy storage device and the thermal storage device.

6. The composite energy storage power supply system as described in claim 5, characterized in that, Also includes: An environmental / load forecasting device is communicatively connected to the central management device, generates forecast data including external environmental conditions and load changes on the common AC bus, and sends the forecast data to the central management device.

7. The composite energy storage power supply system as described in claim 5, characterized in that, The battery energy storage device also includes: An energy module, comprising heat dissipation, measurement, and signal circuits, for providing energy storage; The control module provides an external communication interface, monitors the status of the energy module and PCS, schedules the charging and discharging power settings according to instructions from the local coordination and processing controller, and controls the operation of the battery energy storage device. The power module responds to the commands generated by the control module, controls the charging and discharging of the energy module, and provides the grid connection interface for the composite energy storage power supply system.

8. A method for regulating a composite energy storage power supply system for power grid peak shaving and frequency regulation, wherein the composite energy storage power supply system according to any one of claims 1 to 7 is regulated, characterized in that, Includes the following steps: The total power demand calculation step involves the central management device integrating grid peak-shaving and frequency regulation demand dispatch instructions from the external grid dispatch system, local photovoltaic and solar thermal power generation status information from the environmental / load forecasting device, and forecast data of external environment and the load changes of the common AC bus, to provide the total power demand information of the composite energy storage system. The power output step of the thermal storage device involves outputting the power output information of the thermal storage device to the central management device based on the total power demand information of the composite energy storage system and the state of charge of the thermal storage device. The central management device feedback step calculates the power difference based on the power output information of the thermal storage device and outputs it to the battery energy storage device. The power output step of the battery energy storage device system involves outputting battery energy storage device power output information to the central management device based on the power difference and the state of charge of the battery energy storage device.

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