Wind storage combined primary frequency modulation method and system for deep and far sea wind power plant

Abstract

The invention relates to a wind storage combined primary frequency modulation method and system for a deep and far sea wind power plant. Collecting a network side active power initial value of a land connection transformer of the deep and far sea wind power plant, a wind turbine generator reserve capacity initial value of the deep and far sea wind power plant and an operation power initial value of energy storage of the deep and far sea wind power plant; calculating the total active power change demand value of the deep and far sea wind power plant under the current disturbance frequency; calculating a primary frequency modulation active power change demand value of a wind turbine generator of the deep and far sea wind power plant and a primary frequency modulation active power change demand value of energy storage of the deep and far sea wind power plant; and performing primary frequency modulation according to the total active power change demand value of the deep and far sea wind power plant, the primary frequency modulation active power change demand value of the wind turbine generator and the primary frequency modulation active power change demand value of the energy storage.

Description

Technical Field

[0001] The invention relates to a wind storage combined primary frequency modulation method and system for a deep sea wind farm, belonging to the technical field of offshore wind power. Background Art

[0002] Large-capacity deep-sea wind farms that are transmitted via flexible direct current are different from AC transmission in that the flexible direct current transmission system isolates the wind farm from the connected power grid. Therefore, traditional primary frequency regulation technology is not applicable to this transmission scheme. Currently, large-capacity deep-sea wind farms that have been put into operation via flexible direct current transmission in China do not have primary frequency regulation operating conditions, so this technology is still in the exploratory stage.

[0003] The current offshore wind power transmitted by flexible direct current has several characteristics:

[0004] The wind farm is more than 70 kilometers or even more than 100 kilometers away from the land. The communication distance is long, and there is a large delay between the sending and execution of all control strategies;

[0005] The control of flexible DC systems is complex. Major changes to the control strategy may cause system instability, but minor changes to the strategy can maintain system stability.

[0006] The current returns from offshore wind power are relatively low and the maintenance costs are high. The large energy gap required for primary frequency regulation will cause too much loss for the wind farm.

[0007] Wind farms, energy storage, etc. may belong to different manufacturers, and their control systems are independent of each other, making joint control technology extremely difficult to implement.

[0008] There are currently several main strategies for primary frequency regulation of offshore wind power transmitted by flexible DC:

[0009] The wind turbine adjusts its frequency according to the grid frequency: the grid frequency on land is transmitted to the offshore wind turbine through communication, and the primary frequency modulation function is realized by the primary frequency modulation system of the wind turbine. This method is relatively simple, but it is difficult to solve problems such as long communication distance and long delay;

[0010] Utilize flexible system coupling: The flexible system tracks the grid frequency and enables offshore wind turbines to sense grid frequency changes by modifying the DC voltage amplitude and offshore grid frequency, thereby using their own control system to achieve primary frequency modulation. This method has a faster control speed, but affects the safety and stability of the flexible system.

[0011] Wind-storage joint dynamic primary frequency regulation: Use wind turbines and energy storage to build a joint energy control to achieve primary frequency regulation. For example, the invention patent with publication number "CN115313426A" discloses a wind-storage dynamic primary frequency regulation method suitable for offshore wind farms, including: constructing an offshore wind farm grid-connected power generation system and a system frequency response model, obtaining the total frequency regulation power support of the wind turbines and inputting it, outputting the grid frequency change rate and grid frequency deviation; obtaining environmental parameters and performance parameters, and using the Delphi-entropy weight method to obtain performance factors based on the environmental parameters and performance parameters; using a fuzzy control algorithm to obtain the output power of the offshore wind turbines and energy storage devices. rate; adjust the output power of each current offshore wind turbine and energy storage device to achieve dynamic primary frequency modulation of wind-storage joint in offshore wind farm grid-connected power generation system; the invention combines the Delphi-entropy weight method and fuzzy control algorithm, proposes a primary frequency modulation of wind turbines and energy storage devices considering performance factors, reasonably optimizes the output distribution of wind turbines and energy storage devices, and achieves the mitigation of wind turbine performance deterioration. The patent establishes a joint control strategy and implements the adjustment of wind turbine and energy storage output. In theory, the solution is better, but in practice there are problems such as communication delay, inconsistent control strategy, inconsistent response rate, etc., which makes it difficult to apply in practice. Summary of the invention

[0012] In order to solve the above problems existing in the prior art, the present invention proposes a wind-storage combined primary frequency regulation method and system for deep sea wind farms.

[0013] The technical solution of the present invention is as follows:

[0014] In one aspect, the present invention provides a method for combining wind and storage with primary frequency regulation in a deep sea wind farm, comprising the following steps:

[0015] When the disturbance frequency of the power grid exceeds the frequency regulation dead zone, the initial value of the grid-side active power of the onshore connection transformer of the deep-sea wind farm, the initial value of the standby capacity of the wind turbines in the deep-sea wind farm, and the initial value of the operating power of the energy storage in the deep-sea wind farm are collected;

[0016] Calculate the overall active power change demand value of deep sea wind farms under the current disturbance frequency;

[0017] Based on the overall active power change demand value of the deep-sea wind farm at the current disturbance frequency, the initial value of the grid-side active power of the onshore connection transformer of the deep-sea wind farm, the initial value of the reserve capacity of the wind turbines in the deep-sea wind farm, and the initial value of the operating power of the energy storage in the deep-sea wind farm, the primary frequency regulation active power change demand value of the wind turbines in the deep-sea wind farm and the primary frequency regulation active power change demand value of the energy storage in the deep-sea wind farm are calculated;

[0018] A primary frequency regulation is performed according to the overall active power change demand value of the deep-sea wind farm, the primary frequency regulation active power change demand value of the wind turbines, and the primary frequency regulation active power change demand value of the energy storage.

[0019] As a preferred embodiment of the present invention, the steps for calculating the overall active power change demand value of the deep sea wind farm are:

[0020] Assume that the total active power change demand value of deep sea wind farm is ΔP S , assuming that the rated active power of the deep sea wind farm is P Se , the rated frequency of the power grid is f Se , the primary frequency change value of the grid side is Δf S , the static frequency regulation effect coefficient of the primary frequency regulation of deep sea wind farm is σ ％ , construct the following formula:

[0021]

[0022] Let f r is the grid disturbance frequency, when f r >f Se When , we get the following formula:

[0023] Δf S =-max{|(f Se -f d )-f r |,0};

[0024] When f r <f Se When , we get the following formula:

[0025] Δf S =max{(f Se -f d )-f r , 0}.

[0026] As a preferred embodiment of the present invention, the steps for calculating the primary frequency modulation active power change demand value of the wind turbines in the deep sea wind farm are as follows:

[0027] Assume that the positive reserve capacity of the wind turbine is P WTB+ , then:

[0028] P WTB+ =P WTM -P WT0 ;

[0029] Where: P WTM is the maximum power generation of the wind turbine; P WT0 is the actual power generation of the wind turbine;

[0030] Assume that the positive reserve capacity of the wind turbine is P WTB+ , then:

[0031] P WTB- =P WT0 ;

[0032] If the overall active power change demand value of the deep-sea wind farm is positive, the positive deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated WTB+ , as shown in the following formula:

[0033] ΔP WTB+ =max{ΔP WT -P WTB ,0};

[0034] At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below:

[0035] ΔP WT =min{P WTB+ , ΔP S};

[0036] If the overall active power change demand value of the deep-sea wind farm is negative, the negative deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated. WTB- , as shown in the following formula:

[0037] ΔP WTB- =-max{|ΔP WT |-|P WTB- |,0};

[0038] At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below:

[0039] ΔP WT =-min{|P WTB- |,|ΔP S |}.

[0040] As a preferred embodiment of the present invention, the steps for calculating the change demand value of primary frequency modulation active power of the deep sea wind farm energy storage are as follows:

[0041] Assume that the proportional coefficient of primary frequency regulation active power control of deep sea wind farm energy storage is k p , assuming that the integral coefficient of primary frequency regulation active power control of deep sea wind farm energy storage is k i , assuming that the primary frequency regulation active power change demand of deep sea wind farm energy storage is ΔP ES ;

[0042] When the overall active power change demand value of the deep sea wind farm is positive, the following formula is obtained:

[0043] ΔP ES =ΔP WTB ++k p *[ΔP S -(P S -P S0 )]+k i *∫[ΔP S -(P S -P S0 )]dt;

[0044] Where: P S0 is the initial value of the grid-side active power of the onshore connection transformer of the deep sea wind farm; P S is the grid-side active power value of the onshore connection transformer of the current deep-sea wind farm;

[0045] When the overall active power change demand value of the deep sea wind farm is negative, the following formula is obtained:

[0046] ΔP ES =ΔP WTB- +k p *[ΔP S -(P S -P S0 )]+k i *∫[ΔP S -(P S -P S0 )]dt.

[0047] As a preferred embodiment of the present invention, the active power change demand of primary frequency regulation of deep sea wind farm energy storage is limited by setting the positive upper limit and negative lower limit of active power output, and the specific steps are as follows:

[0048] Assume that the rated active power of the deep sea wind farm energy storage is P ESe , the initial operating power value of the deep sea wind farm energy storage is P ES0 ;

[0049] If P ES0 is positive, then the positive upper limit of active power output of deep sea wind farm energy storage is P ESmax+ and negative lower limit P ESmax- As shown below:

[0050] P ESmax+ =P ESe -P ES0 ;

[0051] P ESmax- =-P ESe -P ES0 ;

[0052] If PES0 If it is negative, the positive upper limit of the active power output of deep sea wind farm energy storage is P ESmax+ and negative lower limit P ESmax- As shown below:

[0053] P ESmax+ =P ESe -P ES0

[0054] P ESmax- =-P ESe -P ES0 ;

[0055] The active power change demand of primary frequency regulation of deep sea wind farm energy storage is constrained by the output positive upper limit P ESmax+ and negative lower limit P ESmax- Between, specifically: P ESmax- <ΔP ES <P ESmax+ .

[0056] On the other hand, the present invention also provides a wind-storage combined primary frequency regulation system for a deep-sea wind farm, including a data acquisition module, a deep-sea wind farm overall active power change demand calculation module, a wind turbine and deep-sea wind farm energy storage primary frequency regulation active power change demand value calculation module, and a primary frequency regulation module;

[0057] The data acquisition module is used to collect the initial value of the grid-side active power of the onshore connection transformer of the deep sea wind farm, the initial value of the standby capacity of the wind turbines in the deep sea wind farm, and the initial value of the operating power of the deep sea wind farm energy storage when the disturbance frequency of the power grid exceeds the frequency modulation dead zone;

[0058] The deep sea wind farm overall active power change demand calculation module is used to calculate the deep sea wind farm overall active power change demand value under the current disturbance frequency;

[0059] The wind turbine and energy storage primary frequency modulation active power change demand value calculation module is used to calculate the primary frequency modulation active power change demand value of the wind turbine in the deep sea wind farm and the primary frequency modulation active power change demand value of the deep sea wind farm energy storage based on the overall active power change demand value of the deep sea wind farm at the current disturbance frequency, the initial value of the grid-side active power of the onshore connection transformer of the deep sea wind farm, the initial value of the standby capacity of the wind turbine in the deep sea wind farm, and the initial value of the operating power of the deep sea wind farm energy storage;

[0060] The primary frequency regulation module is used to perform primary frequency regulation according to the overall active power change demand value of the deep sea wind farm, the primary frequency regulation active power change demand value of the wind turbine generator and the primary frequency regulation active power change demand value of the energy storage.

[0061] As a preferred embodiment of the present invention, the steps for calculating the overall active power change demand value of the deep sea wind farm are:

[0062] Assume that the total active power change demand value of deep sea wind farm is ΔP S , assuming that the rated active power of the deep sea wind farm is P Se , the rated frequency of the power grid is f Se , the primary frequency change value of the grid side is Δf S , the static frequency regulation effect coefficient of the primary frequency regulation of deep sea wind farm is σ ％ , construct the following formula:

[0063]

[0064] Let f r is the grid disturbance frequency, when f r >f Se When , we get the following formula:

[0065] Δf S =-max{|(f Se -f d )-f r |,0};

[0066] When f r <f Se When , we get the following formula:

[0067] Δf S =max{(f Se -f d )-f r , 0}.

[0068] As a preferred embodiment of the present invention, the steps for calculating the primary frequency modulation active power change demand value of the wind turbines in the deep sea wind farm are as follows:

[0069] Assume that the positive reserve capacity of the wind turbine is P WTB+ , then:

[0070] P WTB+ =P WTM -P WT0 ;

[0071] Where: P WTM is the maximum power generation of the wind turbine; P WT0 is the actual power generation of the wind turbine;

[0072] Assume that the positive reserve capacity of the wind turbine is P WTB+ , then:

[0073] P WTB- =P WT0 ;

[0074] If the overall active power change demand value of the deep-sea wind farm is positive, the positive deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated WTB+ , as shown in the following formula:

[0075] ΔP WTB+ =max{ΔP WT -P WTB ,0};

[0076] At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below:

[0077] ΔP WT =min{P WTB+ , ΔP S};

[0078] If the overall active power change demand value of the deep-sea wind farm is negative, the negative deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated. WTB- , as shown in the following formula:

[0079] ΔP WTB- =-max{|ΔP WT |-|P WTB- |,0};

[0080] At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below:

[0081] ΔP WT =-min{|P WTB- |,|ΔP S |}.

[0082] On the other hand, the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method described in any embodiment of the present invention is implemented.

[0083] In yet another aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in any embodiment of the present invention.

[0084] The present invention has the following beneficial effects:

[0085] 1. The present invention utilizes the energy storage system to make up for the problem of insufficient primary frequency modulation response rate and insufficient capacity of deep sea wind turbines. Through the rapid response of energy storage, the primary frequency modulation active power output of the entire wind farm to the power grid can be formed in a short time.

[0086] 2. The present invention only requires the configuration of a wind storage combined with a primary frequency regulation system on land, without the need for communication with the sea, which greatly reduces the construction cost.

[0087] 3. The present invention does not require direct coordination between energy storage and the wind turbine, but issues active power control instructions respectively through the measured system active power conditions, and adjusts the energy storage active power through the proportional integral method, which is easier to implement in practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] Figure 1 is a flow chart of the method of the present invention;

[0089] Figure 2 Topology diagram of offshore wind power system with flexible direct current transmission. DETAILED DESCRIPTION

[0090] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0091] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0092] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0093] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0094] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0095] Embodiment 1:

[0096] See also Figure 1 , a wind storage combined primary frequency modulation method for a deep sea wind farm, comprising the following steps:

[0097] When the disturbance frequency of the power grid exceeds the frequency regulation dead zone, the initial value of the grid-side active power of the onshore connection transformer of the deep-sea wind farm, the initial value of the standby capacity of the wind turbines in the deep-sea wind farm, and the initial value of the operating power of the energy storage in the deep-sea wind farm are collected;

[0098] Calculate the overall active power change demand value of deep sea wind farms under the current disturbance frequency;

[0099] Based on the overall active power change demand value of the deep-sea wind farm at the current disturbance frequency, the initial value of the grid-side active power of the onshore connection transformer of the deep-sea wind farm, the initial value of the reserve capacity of the wind turbines in the deep-sea wind farm, and the initial value of the operating power of the energy storage in the deep-sea wind farm, the primary frequency regulation active power change demand value of the wind turbines in the deep-sea wind farm and the primary frequency regulation active power change demand value of the energy storage in the deep-sea wind farm are calculated;

[0100] A primary frequency regulation is performed according to the overall active power change demand value of the deep-sea wind farm, the primary frequency regulation active power change demand value of the wind turbines, and the primary frequency regulation active power change demand value of the energy storage.

[0101] For offshore wind power transmitted by flexible DC, deep sea wind farms Figure 2 As shown, it includes sea-land converter valve, DC submarine cable, offshore wind turbine and supporting energy storage. The supporting energy storage is set on the low-voltage side of the onshore connecting transformer;

[0102] As a preferred implementation of this embodiment, the steps for calculating the overall active power change demand value of the deep sea wind farm are:

[0103] Assume that the total active power change demand value of deep sea wind farm is ΔP S , assuming that the rated active power of the deep sea wind farm is P Se , the rated frequency of the power grid is f Se , the primary frequency change value of the grid side is Δf S , the static frequency regulation effect coefficient of the primary frequency regulation of deep sea wind farm is σ ％ , construct the following formula:

[0104]

[0105] Let f r is the grid disturbance frequency, when f r >f Se When , we get the following formula:

[0106] Δf S =-max{|(f Se -f d )-f r |,0};

[0107] When fr <f Se When , we get the following formula:

[0108] Δf S =max{(f Se -f d )-f r , 0}.

[0109] As a preferred implementation of this embodiment, the steps for calculating the primary frequency modulation active power change demand value of the wind turbines in the deep sea wind farm are as follows:

[0110] Assume that the positive reserve capacity of the wind turbine is P WTB+ , then:

[0111] P WTB+ =P WTM -P WT0 ;

[0112] Where: P WTM is the maximum power generation of the wind turbine; P WT0 is the actual power generation of the wind turbine;

[0113] Assume that the positive reserve capacity of the wind turbine is P WTB+ , then:

[0114] P WTB- =P WT0 ;

[0115] If the overall active power change demand value of the deep-sea wind farm is positive, the positive deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated WTB+ , as shown in the following formula:

[0116] ΔP WTB+ =max{ΔP WT -P WTB ,0};

[0117] At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below:

[0118] ΔP WT =min{P WTB+ , ΔP S};

[0119] If the overall active power change demand value of the deep-sea wind farm is negative, the negative deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated. WTB- , as shown in the following formula:

[0120] ΔP WTB- =-max{|ΔP WT |-|PWTB- |,0};

[0121] At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below:

[0122] ΔP WT =-min{|P WTB- |,|ΔP S |}.

[0123] As a preferred implementation of this embodiment, the steps for calculating the change demand value of primary frequency modulation active power of the deep sea wind farm energy storage are as follows:

[0124] Since the wind turbines are located at sea, the response speed of primary frequency regulation is slow, and the adjustment speed of wind turbines is slow, but the capacity reserve of wind turbines is large. Therefore, energy storage mainly realizes the rapid response and adjustment function of primary frequency regulation. The proportional integral control system is adopted. The proportional integral control system proportional coefficient of primary frequency regulation active power control of deep sea wind farm energy storage is k. p , assuming that the integral coefficient of the proportional integral control system of the primary frequency regulation active power control of the deep sea wind farm energy storage is k i , assuming that the primary frequency regulation active power change demand of deep sea wind farm energy storage is ΔP ES ;

[0125] When the overall active power change demand value of the deep sea wind farm is positive, the following formula is obtained:

[0126] ΔP ES =ΔP WTB+ +k p *[ΔP S -(P S -P S0 )]+k i *∫[ΔP S -(P S -P S0 )]dt;

[0127] Where: P S0 is the initial value of the grid-side active power of the onshore connection transformer of the deep sea wind farm; P S is the grid-side active power value of the onshore connection transformer of the current deep-sea wind farm;

[0128] When the overall active power change demand value of the deep sea wind farm is negative, the following formula is obtained:

[0129] ΔP ES =ΔP WTB- +k p *[ΔP S -(P S -PS0 )]+k i *∫[ΔP S -(P S -P S0 )]dt.

[0130] As a preferred implementation of this embodiment, the active power change demand of primary frequency regulation of deep sea wind farm energy storage is limited by setting the positive upper limit and negative lower limit of active power output. The specific steps are as follows:

[0131] Assume that the rated active power of the deep sea wind farm energy storage is P ESe , the initial operating power value of the deep sea wind farm energy storage is P ES0 ;

[0132] If P ES0 is positive, then the positive upper limit of active power output of deep sea wind farm energy storage is P ESmax+ and negative lower limit P ESmax- As shown below:

[0133] P ESmax+ =P ESe -P ES0 ;

[0134] P ESmax- =-P ESe -P ES0 ;

[0135] If P ES0 If it is negative, the positive upper limit of the active power output of deep sea wind farm energy storage is P ESmax+ and negative lower limit P ESmax- As shown below:

[0136] P ESmax+ =P ESe -P ES0 ;

[0137] P ESmax- =-P ESe -P ES0 ;

[0138] The active power change demand of primary frequency regulation of deep sea wind farm energy storage is constrained by the output positive upper limit P ESmax+ and negative lower limit P ESmax- Between, specifically: P ESmax- <ΔP ES <P ESmax+ .

[0139] As a preferred implementation mode of this embodiment, if after one frequency modulation, the current grid frequency still exceeds the frequency modulation dead zone, the overall active power change demand value of the deep sea wind farm under the current disturbance frequency, the primary frequency modulation active power change demand value of the wind turbines in the deep sea wind farm and the primary frequency modulation active power change demand value of the energy storage in the deep sea wind farm are recalculated, and the frequency is adjusted again according to the calculation results, and the above operation is repeated until the grid frequency is lower than the frequency modulation dead zone.

[0140] Embodiment 2:

[0141] A wind-storage combined primary frequency regulation system for a deep-sea wind farm, comprising a data acquisition module, a deep-sea wind farm overall active power change demand calculation module, a wind turbine and energy storage primary frequency regulation active power change demand value calculation module, and a primary frequency regulation module;

[0142] The data acquisition module is used to collect the initial value of the grid-side active power of the onshore connection transformer of the deep sea wind farm, the initial value of the standby capacity of the wind turbines in the deep sea wind farm, and the initial value of the operating power of the deep sea wind farm energy storage when the disturbance frequency of the power grid exceeds the frequency modulation dead zone;

[0143] The deep sea wind farm overall active power change demand calculation module is used to calculate the deep sea wind farm overall active power change demand value under the current disturbance frequency;

[0144] The wind turbine and energy storage primary frequency modulation active power change demand value calculation module is used to calculate the primary frequency modulation active power change demand value of the wind turbine in the deep sea wind farm and the primary frequency modulation active power change demand value of the deep sea wind farm energy storage based on the overall active power change demand value of the deep sea wind farm at the current disturbance frequency, the initial value of the grid-side active power of the onshore connection transformer of the deep sea wind farm, the initial value of the standby capacity of the wind turbine in the deep sea wind farm, and the initial value of the operating power of the deep sea wind farm energy storage;

[0145] The primary frequency regulation module is used to perform primary frequency regulation according to the overall active power change demand value of the deep sea wind farm, the primary frequency regulation active power change demand value of the wind turbine generator and the primary frequency regulation active power change demand value of the energy storage.

[0146] As a preferred implementation of this embodiment, the steps for calculating the overall active power change demand value of the deep sea wind farm are:

[0147] Assume that the total active power change demand value of deep sea wind farm is ΔP S , assuming that the rated active power of the deep sea wind farm is P Se , the rated frequency of the power grid is f Se , the primary frequency change value of the grid side is Δf S, the static frequency regulation effect coefficient of the primary frequency regulation of deep sea wind farm is σ ％ , construct the following formula:

[0148]

[0149] Let f r is the grid disturbance frequency, when f r >f Se When , we get the following formula:

[0150] Δf S =-max{|(f Se -f d )-f r |,0};

[0151] When f r <f Se When , we get the following formula:

[0152] Δf S =max{(f Se -f d )-f r , 0}.

[0153] As a preferred implementation of this embodiment, the steps for calculating the primary frequency modulation active power change demand value of the wind turbines in the deep sea wind farm are as follows:

[0154] Assume that the positive reserve capacity of the wind turbine is P WTB+ , then:

[0155] P WTB+ =P WTM -P WT0 ;

[0156] Where: P WTM is the maximum power generation of the wind turbine; P WT0 is the actual power generation of the wind turbine;

[0157] Assume that the positive reserve capacity of the wind turbine is P WTB+ , then:

[0158] P WTB- =P WT0 ;

[0159] If the overall active power change demand value of the deep-sea wind farm is positive, the positive deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated WTB+ , as shown in the following formula:

[0160] ΔP WTB+ =max{ΔP WT -P WTB ,0};

[0161] At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below:

[0162] ΔP WT =min{P WTB+ , ΔP S};

[0163] If the overall active power change demand value of the deep-sea wind farm is negative, the negative deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated. WTB- , as shown in the following formula:

[0164] ΔP WTB =-max{|ΔP WT |-|P WTB- |,0};

[0165] At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below:

[0166] ΔP WT =-min{|P WTB- |,|ΔP S |}.

[0167] The entire wind farm is equipped with a wind-storage combined primary frequency regulation control system, which is implemented by a server with built-in control software. The server communicates with the energy storage system and the wind turbine control system through a network port or a serial port. The system is used to implement the method in Example 1 and will not be repeated here.

[0168] Embodiment three:

[0169] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any embodiment of the present invention when executing the program.

[0170] Embodiment 4:

[0171] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method described in any embodiment of the present invention is implemented.

[0172] In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c can be single or multiple.

[0173] Those of ordinary skill in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented in a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0174] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0175] In several embodiments provided in the present application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory; hereinafter referred to as: ROM), random access memory (Random Access Memory; hereinafter referred to as: RAM), disk or optical disk, and other media that can store program codes.

[0176] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A wind-storage combined primary frequency modulation method for deep sea wind farms, characterized in that: The following steps are involved: When the disturbance frequency of the power grid exceeds the frequency regulation dead zone, the initial value of the grid-side active power of the onshore connection transformer of the deep-sea wind farm, the initial value of the standby capacity of the wind turbines in the deep-sea wind farm, and the initial value of the operating power of the energy storage in the deep-sea wind farm are collected; Calculate the overall active power change demand value of deep sea wind farm under the current disturbance frequency; Based on the overall active power change demand value of the deep-sea wind farm at the current disturbance frequency, the initial value of the grid-side active power of the onshore connection transformer of the deep-sea wind farm, the initial value of the reserve capacity of the wind turbines in the deep-sea wind farm, and the initial value of the operating power of the energy storage in the deep-sea wind farm, the primary frequency regulation active power change demand value of the wind turbines in the deep-sea wind farm and the primary frequency regulation active power change demand value of the energy storage in the deep-sea wind farm are calculated; A primary frequency regulation is performed based on the overall active power change demand value of the deep-sea wind farm, the primary frequency regulation active power change demand value of the wind turbines, and the primary frequency regulation active power change demand value of the energy storage.

2. The method for combining wind and storage with primary frequency modulation in a deep sea wind farm according to claim 1, characterized in that: The calculation steps of the overall active power change demand value of the deep sea wind farm are as follows: Assume that the total active power change demand value of deep sea wind farm is ΔP S , assuming that the rated active power of the deep sea wind farm is P Se , the rated frequency of the power grid is f Se , the primary frequency change value of the grid side is Δf S , the static frequency regulation effect coefficient of the primary frequency regulation of the deep sea wind farm is σ ％ , construct the following formula: Let f r is the grid disturbance frequency, when f r >f Se When , we get the following formula: Δf S =-max{|(f Se -f d )-f r |,0}; When f r <f Se When , we get the following formula: Δf S =max{(f Se -f d )-f r ,0}。 3. A wind-storage combined primary frequency modulation method for deep sea wind farms according to claim 2, characterized in that: The steps for calculating the change demand value of primary frequency modulation active power of the wind turbines in the deep sea wind farm are as follows: Assume that the positive reserve capacity of the wind turbine is P WTB+ , then: P WTB+ =P WTM -P WT0 ; Where: P WTM is the maximum power generation of the wind turbine; P WT0 is the actual power generation of the wind turbine; Assume that the positive reserve capacity of the wind turbine is P WTB+ , then: P WTB- =P WT0 ; If the overall active power change demand value of the deep-sea wind farm is positive, the positive deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated WTB+ , as shown in the following formula: ΔP WTB+ =max{ΔP WT -P WTB ,0}; At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below: ΔP WT =min{P WTB+ ,ΔP S }; If the overall active power change demand value of the deep-sea wind farm is negative, the negative deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated. WTB- , as shown in the following formula: ΔP WTB- =-max{|ΔP WT |-|P WTB- |,0}; At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below: ΔP WT =-min{|P WTB- |,|ΔP S |}。 4. A wind-storage combined primary frequency modulation method for deep sea wind farms according to claim 2, characterized in that: The calculation steps of the primary frequency regulation active power change demand value of the deep sea wind farm energy storage are as follows: Assume that the proportional coefficient of primary frequency regulation active power control of deep sea wind farm energy storage is k p , assuming that the integral coefficient of primary frequency regulation active power control of deep sea wind farm energy storage is k i , assuming that the primary frequency regulation active power change demand of deep sea wind farm energy storage is ΔP ES ; When the overall active power change demand value of the deep sea wind farm is positive, the following formula is obtained: ΔP ES =ΔP WTB+ +k p *[ΔP S -(P S -P S0 )]+k i *∫[ΔP S -(P S -P S0 )]dt; Where: P S0 is the initial value of the grid-side active power of the onshore connection transformer of the deep sea wind farm; P S is the grid-side active power value of the onshore connection transformer of the current deep-sea wind farm; When the overall active power change demand value of the deep sea wind farm is negative, the following formula is obtained: ΔP ES =ΔP WTB- +k p *[ΔP S -(P S -P S0 )]+k i *∫[ΔP S -(P S -P S0 )]dt。 5. A wind-storage combined primary frequency modulation method for deep sea wind farms according to claim 4, characterized in that: By setting the positive upper limit and negative lower limit of active power output, the active power change demand of primary frequency regulation of deep sea wind farm energy storage is restricted. The specific steps are as follows: Assume that the rated active power of the deep sea wind farm energy storage is P ESe , the initial operating power value of deep sea wind farm energy storage is P ES0 ; If P ES0 is positive, then the positive upper limit of active power output of deep sea wind farm energy storage is P ESmax+ and negative lower limit P ESmax- As shown below: P ESmax+ =P ESe -P ES0 ; P ESmax- =-P ESe -P ES0 ; If P ES0 If it is negative, the positive upper limit of the active power output of deep sea wind farm energy storage is P ESmax+ and negative lower limit P ESmax- As shown below: P ESmax+ =P ESe -P ES0 ; P ESmax- =-P ESe -P ES0 ; The active power change demand of primary frequency regulation of deep sea wind farm energy storage is constrained by the output positive upper limit P ESmax+ and negative lower limit P ESmax- Between, specifically: P ESmax- <ΔP ES <P ESmax+ .

6. A wind storage combined primary frequency modulation system for deep sea wind farms, characterized in that: It includes a data acquisition module, a deep-sea wind farm overall active power change demand calculation module, a wind turbine and energy storage primary frequency regulation active power change demand value calculation module, and a primary frequency regulation module; The data acquisition module is used to collect the initial value of the grid-side active power of the onshore connection transformer of the deep sea wind farm, the initial value of the standby capacity of the wind turbines in the deep sea wind farm, and the initial value of the operating power of the deep sea wind farm energy storage when the disturbance frequency of the power grid exceeds the frequency modulation dead zone; The deep sea wind farm overall active power change demand calculation module is used to calculate the deep sea wind farm overall active power change demand value under the current disturbance frequency; The wind turbine and energy storage primary frequency modulation active power change demand value calculation module is used to calculate the primary frequency modulation active power change demand value of the wind turbine in the deep sea wind farm and the primary frequency modulation active power change demand value of the deep sea wind farm energy storage based on the overall active power change demand value of the deep sea wind farm at the current disturbance frequency, the initial value of the grid-side active power of the onshore connection transformer of the deep sea wind farm, the initial value of the standby capacity of the wind turbine in the deep sea wind farm, and the initial value of the operating power of the deep sea wind farm energy storage; The primary frequency regulation module is used to perform primary frequency regulation according to the overall active power change demand value of the deep sea wind farm, the primary frequency regulation active power change demand value of the wind turbine generator and the primary frequency regulation active power change demand value of the energy storage.

7. A wind-storage combined primary frequency modulation system for deep sea wind farms according to claim 6, characterized in that: The calculation steps of the overall active power change demand value of the deep sea wind farm are as follows: Assume that the total active power change demand value of deep sea wind farm is ΔP S , assuming that the rated active power of the deep sea wind farm is P Se , the rated frequency of the power grid is f Se , the primary frequency change value of the grid side is Δf S , the static frequency regulation effect coefficient of the primary frequency regulation of the deep sea wind farm is σ ％ , construct the following formula: Let f r is the grid disturbance frequency, when f r >f Se When , we get the following formula: Δf S =-max{|(f Se -f d )-f r |,0}; When f r <f Se When , we get the following formula: Δf s =max{(f Se -f d )-f r ,0}。 8. The wind-storage combined primary frequency modulation system for deep sea wind farms according to claim 7 is characterized in that: The steps for calculating the change demand value of primary frequency modulation active power of the wind turbines in the deep sea wind farm are as follows: Assume that the positive reserve capacity of the wind turbine is P WTB+ , then: P WTB+ =P WTM -P WT0 ; Where: P WTM is the maximum power generation of the wind turbine; P WT0 is the actual power generation of the wind turbine; Assume that the positive reserve capacity of the wind turbine is P WTB+ , then: P WTB- =P WT0 ; If the overall active power change demand value of the deep-sea wind farm is positive, the positive deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated WTB+ , as shown in the following formula: ΔP WTB+ =max{ΔP WT -P WTB ,0}; At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below: ΔP WT =min{P WTB+ ,ΔP S }; If the overall active power change demand value of the deep-sea wind farm is negative, the negative deficit of the primary frequency regulation active power of the wind turbine generator set ΔP is calculated. WTB- , as shown in the following formula: ΔP WTB- =-max{|ΔP WT |-|P WTB- |,0}; At this time, the primary frequency regulation active power change demand of the wind turbine is ΔP WT As shown below: ΔP WT =-min{|P WTB- |,|ΔP S |}。 9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 5 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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