A grid-side energy storage configuration method and device for suppressing power fluctuation of a wind farm

Abstract

The application relates to a power grid side energy storage configuration method and device for inhibiting wind power plant power fluctuation, which comprises the following steps: determining the rated power of an energy storage system according to the historical time sequence of wind power plant output power; determining the rated capacity of the energy storage system based on the rated power of the energy storage system; and configuring the energy storage system at the power grid side according to the rated power and the rated capacity of the energy storage system; the application obtains the power grid side energy storage configuration scheme for inhibiting wind power plant power fluctuation according to the historical time sequence of wind power plant output power, so that the energy storage system at the power grid side is optimally configured, and the economy of the power grid side energy storage configuration is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power grid frequency modulation technology, and particularly relates to a power grid side energy storage configuration method and device for suppressing wind farm power fluctuation. BACKGROUND

[0002] Wind power has the characteristics of randomness, fluctuation and instability, and is easy to cause frequent power fluctuation of the power grid, which deteriorates power quality. At present, the phenomenon of curtailment of wind power occurs during the operation of wind power, and the problems brought by large-scale grid connection of wind power are increasingly prominent, such as step-out oscillation problem, uncertainty problem of power grid dispatching and prominent additional loss of the power grid. Due to the characteristics of wind power that it is not storable and uncontrollable, wind power consumption has become an important problem faced by the current power system.

[0003] The consumption of wind power is mainly realized by compensation and suppression of power sources with strong load regulation capability. Energy storage technology develops rapidly and is widely applied to the suppression control of intermittent energy such as wind power. Due to its flexible configuration and strong load regulation capability, it is usually combined with other peak shaving and frequency modulation resources to realize the consumption of wind power. For the suppression of large amplitude fluctuation components and high frequency fluctuation components in wind power, hybrid energy storage can be used; considering the advantages of various energy storages, the effect of the energy storage system on suppressing wind power is improved. At present, in the research on application of hybrid energy storage to suppress wind power, most of them only make qualitative analysis of the related economy, and do not consider the optimal configuration of energy storage. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to obtain a power grid side energy storage configuration scheme for suppressing wind farm power fluctuation according to the historical time sequence of wind farm output power, so as to realize the optimal configuration of the power grid side energy storage system and solve the deficiencies of the prior art.

[0005] The purpose of the present application is achieved by using the following technical solutions:

[0006] The present application provides a power grid side energy storage configuration method for suppressing wind farm power fluctuation, and the improvement lies in that the method comprises:

[0007] determining the rated power of the energy storage system according to the historical time sequence of wind farm output power;

[0008] determining the rated capacity of the energy storage system based on the rated power of the energy storage system;

[0009] configuring the energy storage system on the power grid side according to the rated power and the rated capacity of the energy storage system.

[0010] Preferably, the energy storage system comprises a lead-acid battery system, a lithium battery system and a super capacitor system.

[0011] Further, the determining the rated power of the energy storage system according to the historical time series of the wind farm output power comprises:

[0012] The low-frequency component, the medium-frequency component and the high-frequency component of the historical time series of the wind farm output power are obtained, and the rated power of the energy storage system is determined by the following method:

[0013] The absolute value of the maximum peak of the low-frequency component is taken as the rated power of the lead-acid battery system;

[0014] The absolute value of the maximum peak of the medium-frequency component is taken as the rated power of the lithium battery system;

[0015] The absolute value of the maximum peak of the high-frequency component is taken as the rated power of the super capacitor system.

[0016] Further, the obtaining the low-frequency component, the medium-frequency component and the high-frequency component of the historical time series of the wind farm output power comprises:

[0017] The low-frequency component, the medium-frequency component and the high-frequency component of the historical time series of the wind farm output power are obtained by the following formula:

[0018]

[0019] In the formula, P L,m is the mth low-frequency component, P H,s is the sth medium-frequency component, P G,t is the th high-frequency component, θ L is the starting frequency of the low frequency, is the calculation step of the low frequency, θ M is the starting frequency of the medium frequency, is the calculation step of the medium frequency, θ H is the starting frequency of the high frequency, is the calculation step of the high frequency, m∈[1,M], M is the total number of low-frequency components, s∈[1,S], S is the total number of medium-frequency components, t∈[1,T], T is the total number of high-frequency components, P n is the nth data of the historical time series, n∈[1,N], N is the total number of data of the historical time series, j is an imaginary number, e (·) is an exponential function.

[0020] Further, the determining the rated capacity of the energy storage system based on the rated power of the energy storage system comprises:

[0021] The rated capacity E i of the ith energy storage system is determined by the following formula:

[0022] E i = P i t i

[0023] P i i P i i P i

[0024] Based on the same inventive concept, the application also provides a grid-side energy storage configuration device for suppressing wind farm power fluctuation, which is improved in that the device comprises:

[0025] a first determining unit configured to determine the rated power of the energy storage system according to the historical time series of the wind farm output power;

[0026] a second determining unit configured to determine the rated capacity of the energy storage system based on the rated power of the energy storage system;

[0027] a configuration unit configured to configure the energy storage system at the grid side according to the rated power and the rated capacity of the energy storage system.

[0028] Preferably, the energy storage system comprises a lead-acid battery system, a lithium battery system and a super capacitor system.

[0029] Further, the first determining unit is specifically configured to:

[0030] obtain the low-frequency component, the medium-frequency component and the high-frequency component of the historical time series of the wind farm output power, and determine the rated power of the energy storage system by the following method:

[0031] take the absolute value of the maximum peak value of the low-frequency component as the rated power of the lead-acid battery system;

[0032] take the absolute value of the maximum peak value of the medium-frequency component as the rated power of the lithium battery system;

[0033] take the absolute value of the maximum peak value of the high-frequency component as the rated power of the super capacitor system.

[0034] Further, the obtaining of the low-frequency component, the medium-frequency component and the high-frequency component of the historical time series of the wind farm output power comprises:

[0035] obtaining the low-frequency component, the medium-frequency component and the high-frequency component of the historical time series of the wind farm output power by the following formula:

[0036]

[0037] P m L,m P m H,s P s G,t P t L θ m θ mM is the starting frequency of the high frequency, is the calculation step of the high frequency, m∈[1, M], M is the total number of low frequency components, s∈[1, S], S is the total number of medium frequency components, t∈[1, T], T is the total number of high frequency components, P H is the starting frequency of the high frequency, is the calculation step of the high frequency, m∈[1, M], M is the total number of low frequency components, s∈[1, S], S is the total number of medium frequency components, t∈[1, T], T is the total number of high frequency components, P n is the nth data of the historical time series, n∈[1, N], N is the total number of data of the historical time series, j is an imaginary number, e (·) is an exponential function.

[0038] Further, the second determination unit is specifically configured to:

[0039] determine the rated capacity E of the i th energy storage system according to the following formula: i

[0040] E i = P i t i

[0041] In the formula, P i is the rated power of the i th energy storage system, t i is the working time of the i th energy storage system for suppressing the power fluctuation of the wind farm.

[0042] Compared with the closest prior art, the present application has the beneficial effects that:

[0043] The present application provides a grid-side energy storage configuration method and device for suppressing power fluctuation of a wind farm, determines the rated power of an energy storage system according to the historical time series of the output power of the wind farm, determines the rated capacity of the energy storage system based on the rated power of the energy storage system, and configures the energy storage system at the grid side according to the rated power and the rated capacity of the energy storage system. The present application obtains a grid-side energy storage configuration scheme for suppressing power fluctuation of a wind farm according to the historical time series of the output power of the wind farm, so that the grid-side energy storage system is optimally configured, and the economy of the grid-side energy storage configuration is improved. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is a flow chart of the grid-side energy storage configuration method for suppressing power fluctuation of a wind farm of the present application;

[0045] Figure 2 is a schematic diagram of the grid-side energy storage configuration device for suppressing power fluctuation of a wind farm of the present application. DETAILED DESCRIPTION

[0046] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0047] ​In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0048] The present application provides a grid-side energy storage configuration method for suppressing wind farm power fluctuation, as shown in the formula (I), the method comprises: Figure 1

[0049] determining the rated power of the energy storage system according to the historical time series of the wind farm output power;

[0050] determining the rated capacity of the energy storage system based on the rated power of the energy storage system;

[0051] configuring the energy storage system at the grid side according to the rated power and the rated capacity of the energy storage system.

[0052] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0053] In the embodiments of the present application, the energy storage system comprises a lead-acid battery system, a lithium battery system and a super capacitor system.

[0054] In the embodiments of the present application, the above-mentioned determination of the rated power of the energy storage system according to the historical time series of the wind farm output power comprises:

[0055] obtaining the low-frequency component, the medium-frequency component and the high-frequency component of the historical time series of the wind farm output power, and determining the rated power of the energy storage system by the following method:

[0056] taking the absolute value of the maximum peak value of the low-frequency component as the rated power of the lead-acid battery system;

[0057] taking the absolute value of the maximum peak value of the medium-frequency component as the rated power of the lithium battery system;

[0058] taking the absolute value of the maximum peak value of the high-frequency component as the rated power of the super capacitor system.

[0059] Specifically, the above-mentioned obtaining of the low-frequency component, the medium-frequency component and the high-frequency component of the historical time series of the wind farm output power comprises:

[0060] obtaining the low-frequency component, the medium-frequency component and the high-frequency component of the historical time series of the wind farm output power according to the following formula:

[0061] ​

[0062] wherein P L,m is the mth low-frequency component, P H,s is the st mid-frequency component, P G,t is the tth high-frequency component, θ L is the starting frequency of the low frequency, is the calculation step of the low frequency, θ M is the starting frequency of the mid frequency, is the calculation step of the mid frequency, θ H is the starting frequency of the high frequency, is the calculation step of the high frequency, m∈[1,M], M is the total number of low-frequency components, s∈[1,S], S is the total number of mid-frequency components, t∈[1,T], T is the total number of high-frequency components, P n is the nth data of the historical time series, n∈[1,N], N is the total number of data of the historical time series, j is an imaginary number, e (·) is an exponential function.

[0063] In an embodiment of the present application, the power system peak shaving and frequency modulation generally includes three frequency bands of high frequency 0.015Hz-0.5Hz, mid frequency 0.001Hz-0.015Hz, and low frequency 0Hz-0.001Hz. Corresponding to the three frequency bands, corresponding linear frequency modulation Z transform parameters are respectively set as:

[0064]

[0065] In an embodiment of the present application, the above determining the rated capacity of the energy storage system based on the rated power of the energy storage system comprises:

[0066] determining the rated capacity E i of the ith energy storage system according to the following formula:

[0067] E i = P i t i

[0068] wherein P i is the rated power of the ith energy storage system, t i is the working time of the ith energy storage system for suppressing the power fluctuation of the wind farm.

[0069] Based on the same inventive concept, the present application also provides a power grid side energy storage configuration device for suppressing the power fluctuation of a wind farm, as shown in Figure 2 The device comprises:

[0070] a first determining unit, configured to determine the rated power of the energy storage system according to a historical time series of wind farm output power;

[0071] The second determining unit is configured to determine the rated capacity of the energy storage system based on the rated power of the energy storage system.

[0072] The configuring unit is configured to configure the energy storage system at the grid side according to the rated power and the rated capacity of the energy storage system.

[0073] Preferably, the energy storage system comprises a lead-acid battery system, a lithium battery system and a super capacitor system.

[0074] Further, the first determining unit is specifically configured to:

[0075] The first determining unit is configured to determine the rated power of the energy storage system according to the low-frequency component, the medium-frequency component and the high-frequency component of the historical time sequence of the wind farm output power.

[0076] The absolute value of the maximum peak of the low-frequency component is taken as the rated power of the lead-acid battery system.

[0077] The absolute value of the maximum peak of the medium-frequency component is taken as the rated power of the lithium battery system.

[0078] The absolute value of the maximum peak of the high-frequency component is taken as the rated power of the super capacitor system.

[0079] Further, the low-frequency component, the medium-frequency component and the high-frequency component of the historical time sequence of the wind farm output power are obtained by:

[0080] The low-frequency component, the medium-frequency component and the high-frequency component of the historical time sequence of the wind farm output power are obtained by the following formula:

[0081]

[0082] In the formula, P L,m is the mth low-frequency component, P H,s is the sth medium-frequency component, P G,t is the th high-frequency component, θ L is the starting frequency of the low frequency, is the calculation step of the low frequency, θ M is the starting frequency of the medium frequency, is the calculation step of the medium frequency, θ H is the starting frequency of the high frequency, is the calculation step of the high frequency, m∈[1,M], M is the total number of low-frequency components, s∈[1,S], S is the total number of medium-frequency components, t∈[1,T], T is the total number of high-frequency components, P n is the nth data of the historical time sequence, n∈[1,N], N is the total number of data of the historical time sequence, j is an imaginary number, e (·) is an exponential function.

[0083] Furthermore, the second determining unit is specifically used for:

[0084] The rated capacity E of the i-th energy storage system is determined by the following formula. i :

[0085] E i =P i t i

[0086] In the formula, P i Let t be the rated power of the i-th energy storage system. i Let be the operating time of the i-th energy storage system to suppress power fluctuations in the wind farm.

[0087] In summary, this invention provides a grid-side energy storage configuration method and apparatus for suppressing wind farm power fluctuations. The method involves determining the rated power of the energy storage system based on the historical time series of wind farm output power; determining the rated capacity of the energy storage system based on its rated power; and configuring the energy storage system on the grid side according to its rated power and rated capacity. This invention obtains a grid-side energy storage configuration scheme for suppressing wind farm power fluctuations based on the historical time series of wind farm output power, thereby achieving optimal configuration of the grid-side energy storage system and improving the economic efficiency of grid-side energy storage configuration.

[0088] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0089] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0090] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0091] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A grid-side energy storage configuration method for suppressing power fluctuations in wind farms, characterized in that, The method includes: The rated power of the energy storage system is determined based on the historical time series of wind farm output power. Determine the rated capacity of the energy storage system based on its rated power. Configure the energy storage system on the grid side according to the rated power and rated capacity of the energy storage system; The energy storage system includes: a lead-acid battery system, a lithium battery system, and a supercapacitor system; Determining the rated power of the energy storage system based on the historical time series of wind farm output power includes: Obtain the low-frequency, mid-frequency, and high-frequency components of the historical time series of wind farm output power, and determine the rated power of the energy storage system using the following method: The absolute value of the maximum peak value of the low-frequency component is taken as the rated power of the lead-acid battery system. The absolute value of the maximum peak value of the intermediate frequency component is taken as the rated power of the lithium battery system. The absolute value of the maximum peak value of the high-frequency component is taken as the rated power of the supercapacitor system; The acquisition of the low-frequency, mid-frequency, and high-frequency components of the historical time series of wind farm output power includes: The low-frequency, mid-frequency, and high-frequency components of the historical time series of wind farm output power are obtained using the following formula: In the formula, For the m-th low-frequency component, For the s-th intermediate frequency component, For the t-th high-frequency component, The starting frequency is low. For low-frequency calculations, This is the starting frequency of the intermediate frequency. The calculation step size for intermediate frequencies. This is the high-frequency starting frequency. For high-frequency calculation step size, M represents the total number of low-frequency components. S represents the total number of intermediate frequency components. T represents the total number of high-frequency components. For the nth data point in the historical time series, N is the total number of historical time series data, and j is an imaginary number. It is an exponential function.

2. The method as described in claim 1, characterized in that, Determining the rated capacity of an energy storage system based on its rated power includes: The rated capacity of the i-th energy storage system is determined by the following formula. : In the formula, P Let t be the rated power of the i-th energy storage system. Let be the operating time of the i-th energy storage system to suppress power fluctuations in the wind farm.

3. A grid-side energy storage configuration device for suppressing power fluctuations in wind farms, characterized in that, The device includes: The first determining unit is used to determine the rated power of the energy storage system based on the historical time series of the wind farm's output power. The second determining unit is used to determine the rated capacity of the energy storage system based on the rated power of the energy storage system. A configuration unit is used to configure the energy storage system on the grid side according to the rated power and rated capacity of the energy storage system; The energy storage system includes: a lead-acid battery system, a lithium battery system, and a supercapacitor system; The first determining unit is specifically used for: Obtain the low-frequency, mid-frequency, and high-frequency components of the historical time series of wind farm output power, and determine the rated power of the energy storage system using the following method: The absolute value of the maximum peak value of the low-frequency component is taken as the rated power of the lead-acid battery system. The absolute value of the maximum peak value of the intermediate frequency component is taken as the rated power of the lithium battery system. The absolute value of the maximum peak value of the high-frequency component is taken as the rated power of the supercapacitor system; The acquisition of the low-frequency, mid-frequency, and high-frequency components of the historical time series of wind farm output power includes: The low-frequency, mid-frequency, and high-frequency components of the historical time series of wind farm output power are obtained using the following formula: In the formula, For the m-th low-frequency component, For the s-th intermediate frequency component, For the t-th high-frequency component, The starting frequency is low. For low-frequency calculations, This is the starting frequency of the intermediate frequency. The calculation step size for intermediate frequencies. This is the high-frequency starting frequency. For high-frequency calculation step size, M represents the total number of low-frequency components. S represents the total number of intermediate frequency components. T represents the total number of high-frequency components. For the nth data point in the historical time series, N is the total number of historical time series data, and j is an imaginary number. It is an exponential function.

4. The apparatus as described in claim 3, characterized in that, The second determining unit is specifically used for: The rated capacity of the i-th energy storage system is determined by the following formula. : In the formula, P Let t be the rated power of the i-th energy storage system. Let be the operating time of the i-th energy storage system to suppress power fluctuations in the wind farm.

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