Frequency response construction method and device for new energy power system containing gravity energy storage

Abstract

The invention discloses a frequency response construction method and device for a new energy power system containing gravity energy storage, and the method comprises the steps: constructing frequency response-transfer functions based on a thermal power synchronous generator set, wind and light storage equipment and gravity energy storage in the new energy power system; generating an energy frequency response function of the new energy power system on the basis of a frequency response model of a traditional synchronous generator in combination with a plurality of frequency response-transfer functions; and performing aggregation processing on the energy frequency response function of the new energy power system to obtain an energy aggregation frequency response model. According to the method, the influence of the frequency response characteristics of the power system containing the gravity energy storage can be accurately evaluated.

Description

Technical Field

[0001] The present invention belongs to the field of power grid frequency technology, and specifically relates to a frequency response construction method and device for a new energy power system containing gravity energy storage. Background Art

[0002] Gravity energy storage system has become a key technology for peak-shaving and valley-filling of power grids and ensuring safe and stable operation of power grids due to its high safety, environmental friendliness, flexible site selection advantages and low comprehensive cost. In the vertical matrix gravity energy storage system, the topological structure directly connected to the grid can provide the necessary inertia support for the power system. However, due to the mechanical structure characteristics of the gravity energy storage system, its power output is discrete, and the input time of each heavy block is relatively long. At present, the model construction and related mechanisms of gravity energy storage system participating in the frequency response of the power system have not been clarified. This technical gap may lead to our inability to accurately evaluate the impact of gravity energy storage system on the frequency response characteristics of the power system after access. At the same time, most of the existing power systems are large-scale centralized grid-connected wind power and photovoltaic and other renewable energy power systems, which poses a challenge to the safe and stable operation of gravity energy storage system connected to the power grid. Due to the unpredictability, intermittency and volatility of the power output of renewable energy power systems, and the fact that wind power, photovoltaic and energy storage equipment are usually directly connected to the power grid through power electronic converters, the system inertia is reduced, making the frequency stability problem more prominent.

[0003] For example, patent CN114530890A discloses a method for establishing a frequency response model of a power system containing photovoltaic power generation, including the following steps: S1, establishing a model of a conventional unit prime mover-speed regulator; S2, establishing a model of photovoltaic power generation participating in frequency control; S3, establishing an improved SFR model of a power system containing photovoltaic power generation based on the models in S1 and S2; S4, estimating the parameters in the S3 model framework, where some parameters are directly obtained by weighted calculation of the information of each unit, and the remaining parameters are obtained by identification according to the constraints; S5, substituting the parameters obtained in S4 into the S3 model, and predicting the frequency of the system after the disturbance by sensing the power system disturbance event. Although the established model can predict the system frequency response and accurately grasp the maximum frequency deviation, the lowest frequency point time, the steady-state frequency deviation and other information that may exist after the system is disturbed. However, it does not consider the frequency response of the gravity energy storage system connected to the power grid.

[0004] Therefore, how to provide a frequency response construction method for vertical matrix gravity energy storage is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] In view of the defects existing in the above-mentioned prior art, the present invention provides a method and device for constructing the frequency response of a new energy power system including gravity energy storage, which can realize accurate evaluation of the influence of the frequency response characteristics of the power system including gravity energy storage.

[0006] In a first aspect, the present invention provides a method for constructing a frequency response of a new energy power system including gravity energy storage, comprising:

[0007] Based on the thermal power synchronous generator sets, wind and solar storage equipment and gravity energy storage in the new energy power system, the frequency response-transfer function is constructed respectively;

[0008] Based on the frequency response model of traditional synchronous generators and combining multiple frequency response-transfer functions, the energy frequency response function of the new energy power system is generated;

[0009] The energy frequency response functions of the new energy power system are aggregated to obtain an energy aggregation frequency response model.

[0010] Furthermore, based on the thermal power synchronous generator set, wind and solar storage equipment and gravity energy storage in the new energy power system, the frequency response-transfer function is constructed respectively, including:

[0011] Based on the performance parameters of thermal power synchronous generator sets and the corresponding speed governor parameters, the thermal power frequency response transfer function is constructed;

[0012] Provide frequency response support for wind, solar and storage devices connected to the grid via converters, and construct wind, solar and storage frequency response transfer functions;

[0013] Based on the topological structure of gravity energy storage grid-connected and its corresponding frequency response link under the frequency response time scale, a frequency modulation characteristic transfer function is constructed.

[0014] Furthermore, the thermal power frequency response transfer function satisfies the following relationship:

[0015]

[0016] In the formula, ΔP G represents the power response of the thermal power synchronous generator set, Δf represents the frequency change of the new energy power system, K m Represents the mechanical power gain factor, F H is the work coefficient of the high-voltage cylinder of the thermal power synchronous generator set, T R is the reheating time constant, R is the primary frequency modulation droop coefficient of the speed regulator, and s is the Laplace operator.

[0017] Furthermore, wind, solar and storage equipment includes direct-drive wind turbines, photovoltaic units and electrochemical energy storage equipment;

[0018] Provide frequency response support for wind, solar and storage devices connected to the grid via converters, and construct wind, solar and storage frequency response transfer functions, including:

[0019] The frequency response of the direct-drive wind turbine and photovoltaic units connected to the grid via the converter is supported by additional control, and the wind power frequency response transfer function and the photovoltaic frequency response transfer function are constructed respectively;

[0020] The electrochemical frequency response transfer function is constructed by performing a frequency response on the electrochemical energy storage device connected to the grid via the converter.

[0021] Furthermore, the wind power frequency response transfer function is a proportional relationship between the frequency additional control proportional coefficient of the direct-drive wind turbine and the frequency modulation time constant of the direct-drive wind turbine combined with the Laplace operator;

[0022] The photovoltaic frequency response transfer function is the proportional relationship between the frequency additional control proportional coefficient of the photovoltaic unit and the frequency modulation time constant of the photovoltaic unit combined with the Laplace operator;

[0023] The electrochemical frequency response transfer function is a proportional relationship between the frequency additional control proportional coefficient of the electrochemical energy storage device and the frequency modulation time constant of the electrochemical energy storage device combined with the Laplace operator.

[0024] Furthermore, the wind power frequency response transfer function satisfies the following relationship:

[0025]

[0026] In the formula, ΔP W represents the primary frequency regulation power adjustment of the direct-drive wind turbine, Δf represents the frequency change of the new energy power system, K W It represents the frequency additional control proportional coefficient of the direct-drive wind turbine, T W represents the frequency modulation time constant of the direct-drive wind turbine, and s is the Laplace operator;

[0027] The photovoltaic frequency response transfer function satisfies the following relationship:

[0028]

[0029] In the formula, ΔP PV represents the primary frequency modulation power regulation of the photovoltaic unit, Δf represents the frequency change of the new energy power system, K PV Indicates the frequency additional control proportional coefficient of the photovoltaic unit, T PV represents the frequency modulation time constant of the photovoltaic unit, and s is the Laplace operator;

[0030] The electrochemical frequency response transfer function satisfies the following relationship:

[0031]

[0032] Where ΔP E represents the primary frequency modulation power regulation of the electrochemical energy storage device, Δf represents the frequency change of the new energy power system, K E Represents the frequency additional control proportional coefficient of the electrochemical energy storage device, T E represents the frequency modulation time constant of the electrochemical energy storage device, and s is the Laplace operator.

[0033] Furthermore, based on the topological structure of the gravity energy storage grid-connected and its corresponding frequency response link under the frequency response time scale, a frequency modulation characteristic transfer function is constructed, including:

[0034] Based on the topological structure of gravity energy storage grid connection, determine the mechanical torque provided by gravity energy storage at different response times;

[0035] According to the frequency response link corresponding to the gravity energy storage at the frequency response time scale and the mechanical torque provided at different response times, the proportional coefficient of the power response of the gravity energy storage is determined;

[0036] Based on the proportionality coefficient of the gravity energy storage power response and the response time of the gravity energy storage, an intermediate state frequency response coefficient is determined;

[0037] Based on the superposition of the intermediate state frequency response coefficient and the proportionality coefficient of the gravity energy storage power response, the frequency modulation characteristic transfer function is determined.

[0038] Furthermore, based on the frequency response model of the traditional synchronous generator and combined with multiple frequency response-transfer functions, the energy frequency response function of the new energy power system is generated, including:

[0039] Based on the characteristics of wind-solar-storage equipment and gravity energy storage in frequency response through traditional synchronous generators, the wind-solar-storage frequency response transfer function and the frequency modulation characteristic transfer function are respectively added to the frequency response model of the traditional synchronous generator, and the active power change when the wind-solar-storage equipment and gravity energy storage perform frequency response is given;

[0040] Based on the characteristics of frequency response of thermal power synchronous generator sets, the active power variation of thermal power synchronous generator sets when performing frequency response is given;

[0041] Based on the load change of the new energy power system and the difference between the active power change of the thermal power synchronous generator set, wind and solar storage equipment and gravity energy storage when performing frequency response, the intermediate load margin of the new energy power system is determined;

[0042] Based on the inertia proportional constant and damping superposition coefficient of the new energy power system and gravity energy storage, combined with the Laplace operator, the dynamic characteristic quantity of the new energy power system is determined;

[0043] Based on the dynamic characteristics and frequency variation of the renewable energy power system and combined with the intermediate load margin, an energy frequency response function is given.

[0044] Furthermore, the energy frequency response function of the new energy power system is aggregated to obtain an energy aggregation frequency response model, including:

[0045] The wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are aggregated to give a power-frequency frequency domain response aggregation function;

[0046] Based on the power-frequency frequency domain response aggregation function and combined with the intermediate load margin and the frequency change of the new energy power system, the energy frequency response function is updated to obtain the energy aggregation frequency response model.

[0047] Furthermore, the wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are aggregated to give a power-frequency frequency domain response aggregation function, including:

[0048] Based on the wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function, the frequency additional control proportional coefficient and frequency modulation time constant of the direct-drive wind turbine, the frequency additional control proportional coefficient and frequency modulation time constant of the photovoltaic unit, and the frequency additional control proportional coefficient and frequency modulation time constant of the electrochemical energy storage device are respectively obtained;

[0049] Based on the frequency additional control proportional coefficient of the direct-drive wind turbine, photovoltaic unit and electrochemical energy storage device, determine the aggregate frequency additional control proportional coefficient; based on the frequency modulation time constant of the direct-drive wind turbine, photovoltaic unit and electrochemical energy storage device, determine the aggregate frequency modulation time constant;

[0050] The characteristics of wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are analyzed, and the power-frequency frequency domain response aggregation function is given in combination with the aggregation frequency additional control proportional coefficient and the aggregation frequency modulation time constant.

[0051] In a second aspect, the present invention further provides a frequency response construction device for a new energy power system including gravity energy storage, using the frequency response construction method for a new energy power system including gravity energy storage, the frequency response construction device comprises:

[0052] The transfer function building module is used to build frequency response-transfer functions based on thermal power synchronous generator sets, wind and solar storage equipment, and gravity energy storage in the new energy power system;

[0053] A response function building module, which is used to generate an energy frequency response function of a new energy power system based on a frequency response model of a traditional synchronous generator and combined with multiple frequency response-transfer functions;

[0054] The aggregation processing module is used to aggregate the energy frequency response function of the new energy power system to obtain an energy aggregation frequency response model.

[0055] Furthermore, the transfer function building blocks include:

[0056] Based on the performance parameters of thermal power synchronous generator sets and the corresponding speed governor parameters, the thermal power frequency response transfer function is constructed;

[0057] Provide frequency response support for wind, solar and storage devices connected to the grid via converters, and construct wind, solar and storage frequency response transfer functions;

[0058] Based on the topological structure of gravity energy storage grid-connected and its corresponding frequency response link under the frequency response time scale, a frequency modulation characteristic transfer function is constructed.

[0059] Furthermore, the transfer function building blocks include:

[0060] The frequency response of the direct-drive wind turbine and photovoltaic units connected to the grid via the converter is supported by additional control, and the wind power frequency response transfer function and the photovoltaic frequency response transfer function are constructed respectively;

[0061] The electrochemical frequency response transfer function is constructed by performing a frequency response on the electrochemical energy storage device connected to the grid via the converter.

[0062] Furthermore, the transfer function building block also includes:

[0063] Based on the topological structure of gravity energy storage grid connection, determine the mechanical torque provided by gravity energy storage at different response times;

[0064] According to the frequency response link corresponding to the gravity energy storage at the frequency response time scale and the mechanical torque provided at different response times, the proportional coefficient of the power response of the gravity energy storage is determined;

[0065] Based on the proportionality coefficient of the gravity energy storage power response and the response time of the gravity energy storage, an intermediate state frequency response coefficient is determined;

[0066] Based on the superposition of the intermediate state frequency response coefficient and the proportionality coefficient of the gravity energy storage power response, the frequency modulation characteristic transfer function is determined.

[0067] Furthermore, the response function building blocks include:

[0068] Based on the characteristics of wind-solar-storage equipment and gravity energy storage in frequency response through traditional synchronous generators, the wind-solar-storage frequency response transfer function and the frequency modulation characteristic transfer function are respectively added to the frequency response model of the traditional synchronous generator, and the active power change when the wind-solar-storage equipment and gravity energy storage perform frequency response is given;

[0069] Based on the characteristics of frequency response of thermal power synchronous generator sets, the active power variation of thermal power synchronous generator sets when performing frequency response is given;

[0070] Based on the load change of the new energy power system and the difference between the active power change of the thermal power synchronous generator set, wind and solar storage equipment and gravity energy storage when performing frequency response, the intermediate load margin of the new energy power system is determined;

[0071] Based on the inertia proportional constant and damping superposition coefficient of the new energy power system and gravity energy storage, combined with the Laplace operator, the dynamic characteristic quantity of the new energy power system is determined;

[0072] Based on the dynamic characteristics and frequency variation of the renewable energy power system and combined with the intermediate load margin, an energy frequency response function is given.

[0073] Furthermore, the aggregation processing module includes:

[0074] The wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are aggregated to give a power-frequency frequency domain response aggregation function;

[0075] Based on the power-frequency frequency domain response aggregation function and combined with the intermediate load margin and the frequency change of the new energy power system, the energy frequency response function is updated to obtain the energy aggregation frequency response model.

[0076] Furthermore, the aggregation processing module also includes:

[0077] Based on the wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function, the frequency additional control proportional coefficient and frequency modulation time constant of the direct-drive wind turbine, the frequency additional control proportional coefficient and frequency modulation time constant of the photovoltaic unit, and the frequency additional control proportional coefficient and frequency modulation time constant of the electrochemical energy storage device are respectively obtained;

[0078] Based on the frequency additional control proportional coefficient of the direct-drive wind turbine, photovoltaic unit and electrochemical energy storage device, determine the aggregate frequency additional control proportional coefficient; based on the frequency modulation time constant of the direct-drive wind turbine, photovoltaic unit and electrochemical energy storage device, determine the aggregate frequency modulation time constant;

[0079] The characteristics of wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are analyzed, and the power-frequency frequency domain response aggregation function is given in combination with the aggregation frequency additional control proportional coefficient and the aggregation frequency modulation time constant.

[0080] The present invention provides a method and device for constructing a frequency response of a new energy power system with gravity energy storage, which has at least the following beneficial effects:

[0081] (1) Through the obtained energy aggregation frequency response model, it is possible to accurately evaluate the impact of gravity energy storage on the frequency response characteristics of the power system after it is connected to the new energy power system.

[0082] (2) By analyzing and aggregating the frequency response characteristics of wind, solar and storage devices, the frequency response model of the power system can be updated, which can simplify the frequency response evaluation while ensuring the accuracy of the evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 A flow chart of a method for constructing a frequency response of a new energy power system with gravity energy storage provided by the present invention;

[0084] Figure 2 A flowchart of constructing a frequency response-transfer function provided by an embodiment of the present invention;

[0085] Figure 3 A frequency response model diagram of a thermal power synchronous generator set provided in an embodiment of the present invention;

[0086] Figure 4 A flow chart of constructing a wind-solar-storage frequency response transfer function provided by an embodiment of the present invention;

[0087] Figure 5 A flow chart of constructing a frequency modulation characteristic transfer function provided by an embodiment of the present invention;

[0088] Figure 6 A flow chart of generating an energy frequency response function provided by an embodiment of the present invention;

[0089] Figure 7 A flow chart of obtaining an energy aggregation frequency response model provided by an embodiment of the present invention;

[0090] Figure 8 A flowchart of a power-frequency frequency domain response aggregation function provided for an embodiment of the present invention;

[0091] Fig. 9 A frequency response model diagram of a wind-solar-storage device provided in an embodiment of the present invention;

[0092] Fig.10 A schematic diagram of a frequency response construction device for a new energy power system with gravity energy storage provided by the present invention. DETAILED DESCRIPTION

[0093] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0094] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0095] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0096] like Figure 1 As shown, the present invention provides a method for constructing the frequency response of a new energy power system containing gravity energy storage, which accurately characterizes the frequency response characteristics of a power system containing vertical matrix gravity energy storage. Based on the operating characteristics of wind, solar and storage equipment and the frequency response mode of participating in the system, a frequency response model of a multi-machine system containing wind, solar and storage is formed on the basis of the frequency response model of a traditional synchronous electric generator multi-machine system; based on the operating characteristics of gravity energy storage and the frequency response mode of participating in the system, an energy frequency response function containing gravity energy storage and wind, solar and storage is constructed for the energy frequency response function containing wind, solar and storage. Specifically, the frequency response construction method of the present invention includes:

[0097] Based on the thermal power synchronous generator sets, wind and solar storage equipment and gravity energy storage in the new energy power system, the frequency response-transfer function is constructed respectively;

[0098] Based on the frequency response model of traditional synchronous generators and combining multiple frequency response-transfer functions, the energy frequency response function of the new energy power system is generated;

[0099] The energy frequency response functions of the new energy power system are aggregated to obtain an energy aggregation frequency response model.

[0100] Among them, Figure 2 and Figure 3 As shown, based on the thermal power synchronous generator set, wind and solar storage equipment and gravity energy storage in the new energy power system, the frequency response-transfer function is constructed respectively, which may include:

[0101] Based on the performance parameters of the thermal power synchronous generator set and the corresponding speed regulator parameters, the thermal power frequency response transfer function is constructed to meet the following relationship:

[0102]

[0103] In the formula, ΔP G represents the power response of the thermal power synchronous generator set, Δf represents the frequency change of the new energy power system, K m Represents the mechanical power gain factor, F H is the work coefficient of the high-voltage cylinder of the thermal power synchronous generator set, T R is the reheating time constant, R is the primary frequency modulation droop coefficient of the speed regulator, and s is the Laplace operator;

[0104] Provide frequency response support for wind, solar and storage devices connected to the grid via converters, and construct wind, solar and storage frequency response transfer functions;

[0105] Based on the topological structure of gravity energy storage grid-connected and its corresponding frequency response link under the frequency response time scale, a frequency modulation characteristic transfer function is constructed.

[0106] The wind-solar-energy storage device of the present invention comprises a direct-drive wind turbine set, a photovoltaic unit and an electrochemical energy storage device.

[0107] like Figure 4 As shown, the frequency response support for the wind-solar-storage device connected to the grid via the converter is carried out, and the wind-solar-storage frequency response transfer function is constructed, which may include:

[0108] The frequency response of the direct-drive wind turbine and photovoltaic units connected to the grid via the converter is supported by additional control, and the wind power frequency response transfer function and the photovoltaic frequency response transfer function are constructed respectively;

[0109] The electrochemical frequency response transfer function is constructed by performing a frequency response on the electrochemical energy storage device connected to the grid via the converter.

[0110] Among them, further, the wind power frequency response transfer function is the proportional relationship between the frequency additional control proportional coefficient of the direct-drive wind turbine group and the frequency modulation time constant of the direct-drive wind turbine group combined with the Laplace operator; specifically, the wind power frequency response transfer function satisfies the following relationship:

[0111]

[0112] In the formula, ΔP W represents the primary frequency regulation power adjustment of the direct-drive wind turbine, Δf represents the frequency change of the new energy power system, K W It represents the frequency additional control proportional coefficient of the direct-drive wind turbine, T W represents the frequency modulation time constant of the direct-drive wind turbine, and s is the Laplace operator;

[0113] The photovoltaic frequency response transfer function is the proportional relationship between the frequency additional control proportional coefficient of the photovoltaic unit and the frequency modulation time constant of the photovoltaic unit combined with the Laplace operator; specifically, the photovoltaic frequency response transfer function satisfies the following relationship:

[0114]

[0115] In the formula, ΔP PV represents the primary frequency modulation power regulation of the photovoltaic unit, Δf represents the frequency change of the new energy power system, K PV Indicates the frequency additional control proportional coefficient of the photovoltaic unit, T PV represents the frequency modulation time constant of the photovoltaic unit, and s is the Laplace operator;

[0116] The electrochemical frequency response transfer function is a proportional relationship between the frequency additional control proportional coefficient of the electrochemical energy storage device and the frequency modulation time constant of the electrochemical energy storage device combined with the Laplace operator. Specifically, the electrochemical frequency response transfer function satisfies the following relationship:

[0117]

[0118] In the formula, ΔP E represents the primary frequency modulation power regulation of the electrochemical energy storage device, Δf represents the frequency change of the new energy power system, K E Represents the frequency additional control proportional coefficient of the electrochemical energy storage device, T E represents the frequency modulation time constant of the electrochemical energy storage device, and s is the Laplace operator.

[0119] The vertical matrix gravity energy storage system uses a transmission device to pull the elevator car and lift or lower the weight through the elevator car. Its working principle is mainly to achieve electromechanical energy conversion by driving the synchronous machine through discrete weight blocks. According to the above principle, Figure 5 As shown, based on the topological structure of gravity energy storage grid connection and its corresponding frequency response link under the frequency response time scale, the frequency modulation characteristic transfer function is constructed, including:

[0120] Based on the topological structure of gravity energy storage grid connection, determine the mechanical torque provided by gravity energy storage at different response times;

[0121] According to the frequency response link corresponding to the gravity energy storage at the frequency response time scale and the mechanical torque provided at different response times, the proportional coefficient of the power response of the gravity energy storage is determined;

[0122] Based on the proportional coefficient of the gravity energy storage power response and the response time of the gravity energy storage, the intermediate state frequency response coefficient is determined to satisfy the following relationship:

[0123]

[0124] In the formula, α is the intermediate frequency response coefficient, β is the proportional coefficient of the gravity energy storage power response, and T0 is the response time of the gravity energy storage;

[0125] Based on the superposition of the intermediate state frequency response coefficient and the proportionality coefficient of the gravity energy storage power response, the frequency modulation characteristic transfer function is determined.

[0126] After determining the transfer functions of thermal power synchronous generators, wind and solar storage equipment, and gravity energy storage, the energy frequency response function of the new energy power system can be constructed. Figure 6 As shown, based on the frequency response model of the traditional synchronous generator and combined with multiple frequency response-transfer functions, the energy frequency response function of the new energy power system is generated, which may include:

[0127] Based on the characteristics of wind-solar-storage equipment and gravity energy storage in frequency response through traditional synchronous generators, the wind-solar-storage frequency response transfer function and the frequency modulation characteristic transfer function are respectively added to the frequency response model of the traditional synchronous generator, and the active power change when the wind-solar-storage equipment and gravity energy storage perform frequency response is given;

[0128] Based on the characteristics of frequency response of thermal power synchronous generator sets, the active power variation of thermal power synchronous generator sets when performing frequency response is given;

[0129] Load variation ΔP based on new energy power system L , and the difference in active power change when the thermal power synchronous generator set, wind and solar storage equipment and gravity energy storage perform frequency response, to determine the intermediate load margin of the new energy power system;

[0130] Based on the inertia proportional constant and damping superposition coefficient of the new energy power system and gravity energy storage, combined with the Laplace operator, the dynamic characteristic quantity of the new energy power system is determined;

[0131] Based on the dynamic characteristics and frequency variation of the renewable energy power system and combined with the intermediate load margin, an energy frequency response function is given.

[0132] Among them, the inertia proportional constant of gravity energy storage can be determined based on the topological structure of the gravity energy storage unit and the equipment parameters of each equipment in the new energy power system, and the damping superposition coefficient of gravity energy storage is determined based on the damping coefficient of the load, as well as the equipment parameters and damping coefficient of each equipment in the new energy power system.

[0133] like Figure 7 As shown, the energy frequency response function of the new energy power system is aggregated to obtain an energy aggregation frequency response model, which may include:

[0134] The wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are aggregated to give a power-frequency frequency domain response aggregation function;

[0135] Based on the power-frequency frequency domain response aggregation function and combined with the intermediate load margin and the frequency change of the new energy power system, the energy frequency response function is updated to obtain the energy aggregation frequency response model.

[0136] Specifically, Figure 8 As shown, the wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are aggregated to give a power-frequency frequency domain response aggregation function, including:

[0137] Based on the wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function, the frequency additional control proportional coefficient and frequency modulation time constant of the direct-drive wind turbine, the frequency additional control proportional coefficient and frequency modulation time constant of the photovoltaic unit, and the frequency additional control proportional coefficient and frequency modulation time constant of the electrochemical energy storage device are respectively obtained;

[0138] Based on the frequency additional control proportional coefficient of the direct-drive wind turbine, photovoltaic unit and electrochemical energy storage device, determine the aggregate frequency additional control proportional coefficient; based on the frequency modulation time constant of the direct-drive wind turbine, photovoltaic unit and electrochemical energy storage device, determine the aggregate frequency modulation time constant;

[0139] The characteristics of wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are analyzed, and the power-frequency frequency domain response aggregation function is given in combination with the aggregation frequency additional control proportional coefficient and the aggregation frequency modulation time constant.

[0140] like Fig. 9As shown, through the characteristic analysis of wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function, it can be known that the wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function have the same characteristics and response methods. Therefore, the wind power frequency response transfer function, photovoltaic frequency response transfer function or electrochemical frequency response transfer function is updated through the aggregate frequency additional control proportional coefficient and the aggregate frequency modulation time constant to determine the power-frequency frequency domain response aggregation function.

[0141] like Fig.10 As shown, the present invention also provides a frequency response construction device for a new energy power system with gravity energy storage, using the above-mentioned frequency response construction method for a new energy power system with gravity energy storage, the frequency response construction device comprises:

[0142] The transfer function building module is used to build frequency response-transfer functions based on thermal power synchronous generator sets, wind and solar storage equipment, and gravity energy storage in the new energy power system;

[0143] A response function building module, which is used to generate an energy frequency response function of a new energy power system based on a frequency response model of a traditional synchronous generator and combined with multiple frequency response-transfer functions;

[0144] The aggregation processing module is used to aggregate the energy frequency response function of the new energy power system to obtain an energy aggregation frequency response model.

[0145] Furthermore, the transfer function building blocks include:

[0146] Based on the performance parameters of thermal power synchronous generator sets and the corresponding speed governor parameters, the thermal power frequency response transfer function is constructed;

[0147] Provide frequency response support for wind, solar and storage devices connected to the grid via converters, and construct wind, solar and storage frequency response transfer functions;

[0148] Based on the topological structure of gravity energy storage grid-connected and its corresponding frequency response link under the frequency response time scale, a frequency modulation characteristic transfer function is constructed.

[0149] Furthermore, the transfer function building blocks include:

[0150] The frequency response of the direct-drive wind turbine and photovoltaic units connected to the grid via the converter is supported by additional control, and the wind power frequency response transfer function and the photovoltaic frequency response transfer function are constructed respectively;

[0151] The electrochemical frequency response transfer function is constructed by performing a frequency response on the electrochemical energy storage device connected to the grid via the converter.

[0152] Furthermore, the transfer function building block also includes:

[0153] Based on the topological structure of gravity energy storage grid connection, determine the mechanical torque provided by gravity energy storage at different response times;

[0154] According to the frequency response link corresponding to the gravity energy storage at the frequency response time scale and the mechanical torque provided at different response times, the proportional coefficient of the power response of the gravity energy storage is determined;

[0155] Based on the proportionality coefficient of the gravity energy storage power response and the response time of the gravity energy storage, an intermediate state frequency response coefficient is determined;

[0156] Based on the superposition of the intermediate state frequency response coefficient and the proportionality coefficient of the gravity energy storage power response, the frequency modulation characteristic transfer function is determined.

[0157] Furthermore, the response function building blocks include:

[0158] Based on the characteristics of wind-solar-storage equipment and gravity energy storage in frequency response through traditional synchronous generators, the wind-solar-storage frequency response transfer function and the frequency modulation characteristic transfer function are respectively added to the frequency response model of the traditional synchronous generator, and the active power change when the wind-solar-storage equipment and gravity energy storage perform frequency response is given;

[0159] Based on the characteristics of frequency response of thermal power synchronous generator sets, the active power variation of thermal power synchronous generator sets when performing frequency response is given;

[0160] Based on the load change of the new energy power system and the difference between the active power change of the thermal power synchronous generator set, wind and solar storage equipment and gravity energy storage when performing frequency response, the intermediate load margin of the new energy power system is determined;

[0161] Based on the inertia proportional constant and damping superposition coefficient of the new energy power system and gravity energy storage, combined with the Laplace operator, the dynamic characteristic quantity of the new energy power system is determined;

[0162] Based on the dynamic characteristics and frequency variation of the renewable energy power system and combined with the intermediate load margin, an energy frequency response function is given.

[0163] Furthermore, the aggregation processing module includes:

[0164] The wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are aggregated to give a power-frequency frequency domain response aggregation function;

[0165] Based on the power-frequency frequency domain response aggregation function and combined with the intermediate load margin and the frequency change of the new energy power system, the energy frequency response function is updated to obtain the energy aggregation frequency response model.

[0166] Furthermore, the aggregation processing module also includes:

[0167] Based on the wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function, the frequency additional control proportional coefficient and frequency modulation time constant of the direct-drive wind turbine, the frequency additional control proportional coefficient and frequency modulation time constant of the photovoltaic unit, and the frequency additional control proportional coefficient and frequency modulation time constant of the electrochemical energy storage device are respectively obtained;

[0168] Based on the frequency additional control proportional coefficient of the direct-drive wind turbine, photovoltaic unit and electrochemical energy storage device, determine the aggregate frequency additional control proportional coefficient; based on the frequency modulation time constant of the direct-drive wind turbine, photovoltaic unit and electrochemical energy storage device, determine the aggregate frequency modulation time constant;

[0169] The characteristics of wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are analyzed, and the power-frequency frequency domain response aggregation function is given in combination with the aggregation frequency additional control proportional coefficient and the aggregation frequency modulation time constant.

[0170] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A frequency response construction method for a new energy power system with gravity energy storage, characterized in that: include: Based on the thermal power synchronous generator sets, wind and solar storage equipment and gravity energy storage in the new energy power system, the frequency response-transfer function is constructed respectively; Based on the frequency response model of traditional synchronous generators and combining multiple frequency response-transfer functions, the energy frequency response function of the new energy power system is generated; The energy frequency response functions of the new energy power system are aggregated to obtain an energy aggregation frequency response model.

2. The frequency response construction method according to claim 1, characterized in that: Based on the thermal power synchronous generator sets, wind and solar storage equipment and gravity energy storage in the new energy power system, the frequency response-transfer function is constructed respectively, including: Based on the performance parameters of thermal power synchronous generator sets and the corresponding speed governor parameters, the thermal power frequency response transfer function is constructed; Provide frequency response support for wind, solar and storage devices connected to the grid via converters, and construct wind, solar and storage frequency response transfer functions; Based on the topological structure of gravity energy storage grid-connected and its corresponding frequency response link under the frequency response time scale, a frequency modulation characteristic transfer function is constructed.

3. The frequency response construction method according to claim 2, characterized in that: The thermal power frequency response transfer function satisfies the following relationship: Where ΔP G represents the power response of the thermal power synchronous generator set, Δf represents the frequency change of the new energy power system, K m Represents the mechanical power gain factor, F H is the work coefficient of the high-voltage cylinder of the thermal power synchronous generator set, T R is the reheating time constant, R is the primary frequency modulation droop coefficient of the speed regulator, and s is the Laplace operator.

4. The frequency response construction method according to claim 2, characterized in that: Wind, solar and storage equipment includes direct-drive wind turbines, photovoltaic units and electrochemical energy storage equipment; Provide frequency response support for wind, solar and storage devices connected to the grid via converters, and construct wind, solar and storage frequency response transfer functions, including: The frequency response of the direct-drive wind turbine and photovoltaic units connected to the grid via the converter is supported by additional control, and the wind power frequency response transfer function and the photovoltaic frequency response transfer function are constructed respectively; The electrochemical frequency response transfer function is constructed by performing a frequency response on the electrochemical energy storage device connected to the grid via the converter.

5. The frequency response construction method according to claim 4, characterized in that: The wind power frequency response transfer function is the proportional relationship between the frequency additional control proportional coefficient of the direct-drive wind turbine and the frequency modulation time constant of the direct-drive wind turbine combined with the Laplace operator; The photovoltaic frequency response transfer function is the proportional relationship between the frequency additional control proportional coefficient of the photovoltaic unit and the frequency modulation time constant of the photovoltaic unit combined with the Laplace operator; The electrochemical frequency response transfer function is a proportional relationship between the frequency additional control proportional coefficient of the electrochemical energy storage device and the frequency modulation time constant of the electrochemical energy storage device combined with the Laplace operator.

6. The frequency response construction method according to claim 2, characterized in that: Based on the topological structure of gravity energy storage grid connection and its corresponding frequency response link under the frequency response time scale, the frequency modulation characteristic transfer function is constructed, including: Based on the topological structure of gravity energy storage grid connection, determine the mechanical torque provided by gravity energy storage at different response times; According to the frequency response link corresponding to the gravity energy storage at the frequency response time scale and the mechanical torque provided at different response times, the proportional coefficient of the power response of the gravity energy storage is determined; Based on the proportionality coefficient of the gravity energy storage power response and the response time of the gravity energy storage, an intermediate state frequency response coefficient is determined; Based on the superposition of the intermediate state frequency response coefficient and the proportionality coefficient of the gravity energy storage power response, the frequency modulation characteristic transfer function is determined.

7. The frequency response construction method according to claim 2, characterized in that: Based on the frequency response model of traditional synchronous generators and combined with multiple frequency response-transfer functions, the energy frequency response function of the new energy power system is generated, including: Based on the characteristics of wind-solar-storage equipment and gravity energy storage in frequency response through traditional synchronous generators, the wind-solar-storage frequency response transfer function and the frequency modulation characteristic transfer function are respectively added to the frequency response model of the traditional synchronous generator, and the active power change when the wind-solar-storage equipment and gravity energy storage perform frequency response is given; Based on the characteristics of frequency response of thermal power synchronous generator sets, the active power variation of thermal power synchronous generator sets when performing frequency response is given; Based on the load change of the new energy power system and the difference between the active power change of the thermal power synchronous generator set, wind and solar storage equipment and gravity energy storage when performing frequency response, the intermediate load margin of the new energy power system is determined; Based on the inertia proportional constant and damping superposition coefficient of the new energy power system and gravity energy storage, combined with the Laplace operator, the dynamic characteristic quantity of the new energy power system is determined; Based on the dynamic characteristics and frequency variation of the renewable energy power system and combined with the intermediate load margin, an energy frequency response function is given.

8. The frequency response construction method according to claim 7, characterized in that: The energy frequency response function of the new energy power system is aggregated to obtain an energy aggregation frequency response model, including: The wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are aggregated to give a power-frequency frequency domain response aggregation function; Based on the power-frequency frequency domain response aggregation function and combined with the intermediate load margin and the frequency change of the new energy power system, the energy frequency response function is updated to obtain the energy aggregation frequency response model.

9. The frequency response construction method according to claim 8, characterized in that: The wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are aggregated to give the power-frequency frequency domain response aggregation function, including: Based on the wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function, the frequency additional control proportional coefficient and frequency modulation time constant of the direct-drive wind turbine, the frequency additional control proportional coefficient and frequency modulation time constant of the photovoltaic unit, and the frequency additional control proportional coefficient and frequency modulation time constant of the electrochemical energy storage device are respectively obtained; Based on the frequency additional control proportional coefficient of the direct-drive wind turbine group, the photovoltaic unit and the chemical energy storage device, the aggregate frequency additional control proportional coefficient is determined; based on the frequency modulation time constant of the direct-drive wind turbine group, the photovoltaic unit and the chemical energy storage device, the aggregate frequency modulation time constant is determined; The characteristics of wind power frequency response transfer function, photovoltaic frequency response transfer function and electrochemical frequency response transfer function are analyzed, and the power-frequency frequency domain response aggregation function is given in combination with the aggregation frequency additional control proportional coefficient and the aggregation frequency modulation time constant.

10. A frequency response construction device for a new energy power system with gravity energy storage, characterized in that: The frequency response construction method of the new energy power system with gravity energy storage according to any one of claims 1 to 9 is adopted, and the frequency response construction device includes: The transfer function building module is used to build frequency response-transfer functions based on thermal power synchronous generator sets, wind and solar storage equipment, and gravity energy storage in the new energy power system; A response function building module, which is used to generate an energy frequency response function of a new energy power system based on a frequency response model of a traditional synchronous generator and combined with multiple frequency response-transfer functions; The aggregation processing module is used to aggregate the energy frequency response function of the new energy power system to obtain an energy aggregation frequency response model.

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