Improved frequency regulation control method and system of wind turbine generator considering energy storage output mode
By improving the frequency regulation control of wind turbines that take into account energy storage output, and combining rotor kinetic energy, pitch angle and energy storage system control, the problem of insufficient inertia support of wind turbines has been solved, thereby improving grid frequency stability and power generation efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA ELECTRIC POWER RESEARCH INSTITUTE CO LTD
- Filing Date
- 2021-10-29
- Publication Date
- 2026-06-05
Smart Images
Figure CN114069653B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of wind power frequency regulation, and specifically to an improved frequency regulation control method and system for wind turbines that takes into account energy storage output mode. Background Technology
[0002] Unlike traditional synchronous generators, wind turbines are connected to the grid via power electronic devices. Their rotor kinetic energy is decoupled from system frequency changes, meaning they cannot provide inertial support for grid frequency variations. As the proportion of wind power in the power system increases, the system's inertia will continue to decrease, posing a significant challenge to grid frequency stability. Therefore, researching strategies for wind turbine participation in grid frequency regulation control is crucial for large-scale wind power grid integration.
[0003] Currently, extensive research has been conducted on the system frequency instability caused by wind power grid connection. To improve the frequency response capability of wind power generation systems, virtual inertial control and droop control strategies can be added under the maximum power point tracking (MPPT) mode of wind turbines to provide inertial support for grid frequency. However, most studies have not conducted detailed analysis of the inertial coefficients in the control strategies, and few studies have investigated how to perform variable coefficient control on the two existing inertial coefficients when using virtual inertial control and droop control strategies simultaneously. Overspeed standby control methods can put wind turbines in an overspeed operating state to reserve a certain amount of power in advance, thereby providing inertial support for the grid. However, overspeed standby control is limited by the maximum speed, and the adjustable speed range is relatively limited. Adjusting the active power output of the turbine by adjusting the pitch angle can also participate in grid frequency regulation, but since pitch angle adjustment is a mechanical response process, it is slow, and frequent actions increase maintenance costs. Therefore, how to configure the control strategy for wind turbines to participate in system frequency regulation while balancing their own power generation efficiency is an urgent problem to be solved. Summary of the Invention
[0004] To overcome the shortcomings of the prior art, this invention proposes an improved frequency regulation control method for wind turbines that takes into account energy storage output, comprising:
[0005] Obtain the frequency of the wind turbine;
[0006] Determine whether the frequency is less than a preset frequency threshold;
[0007] If the frequency is less than the preset frequency threshold, then wind turbine frequency regulation control and energy storage system control are performed.
[0008] The wind turbine frequency regulation control includes: controlling the wind turbine to perform rotor kinetic energy frequency regulation control and blade pitch angle backup control based on wind speed and wind turbine rotation speed.
[0009] Preferably, the step of controlling the wind turbine to perform rotor kinetic energy frequency regulation control and blade pitch angle backup control based on wind speed and wind turbine rotation speed includes:
[0010] Obtain the rotor speed and wind speed of the wind turbine;
[0011] Determine whether the rotor speed of the wind turbine is less than a preset speed threshold;
[0012] If so, there is no need to control the wind turbine to use rotor kinetic energy for frequency regulation;
[0013] Otherwise, determine whether the wind speed is less than the rated wind speed. If so, control the wind turbine to use the rotor kinetic energy for frequency regulation. Otherwise, add a backup control for the pitch angle on the basis of controlling the wind turbine to use the rotor kinetic energy for frequency regulation.
[0014] Preferably, the control wind turbine utilizes a rotor
[0015] Kinetic energy frequency regulation includes: controlling the wind turbine to perform variable coefficient integrated inertial control and virtual capacitor control, adjusting the rotor kinetic energy, and performing frequency regulation.
[0016] Preferably, the wind turbine is controlled by a variable coefficient integrated inertial control, including:
[0017] The optimal reference speed of the wind turbine is calculated using the optimal wind turbine speed calculation formula based on the wind turbine reference speed, constants related to the frequency change of the wind-storage system, and the frequency change.
[0018] Based on the calculated optimal reference speed of the wind turbine, the rotor kinetic energy of the wind turbine is adjusted, and the frequency of the wind turbine is controlled until the grid frequency returns to the rated frequency.
[0019] The change in frequency is the difference between the rated frequency and the real-time frequency.
[0020] Preferably, the formula for calculating the optimal reference speed of the fan is:
[0021]
[0022] In the formula, K P This is a constant related to the frequency variation of the wind-storage system. The optimal reference rotor speed for the fan. Δf is the reference speed of the fan, and Δf is the difference between the rated frequency and the real-time frequency.
[0023] Preferably, the virtual capacitor control method for controlling wind turbine generators includes:
[0024] The target value of the input power from the rotor-side converter to the DC-side capacitor is calculated based on the virtual capacitor, DC-side voltage, and DC-side power.
[0025] By adjusting the size of the virtual capacitor, the DC-side input power is adjusted to the target value.
[0026] Preferably, the formula for calculating the target value of the input power is:
[0027]
[0028]
[0029] In the formula, P′ in C is the target value of the input power from the rotor-side converter to the DC-side capacitor. vir For virtual capacitance, ΔP vir The additional power provided by the virtual capacitor control strategy, V dc It is the measured DC-side voltage, P in This is the power flowing from the rectifier into the DC-side capacitor.
[0030] Preferably, the wind turbine is controlled to control the energy storage system;
[0031] Determine whether the obtained state of charge of the energy storage system is greater than the preset minimum state of charge value;
[0032] If so, the wind-storage system is controlled by fuzzy logic based on the wind turbine's output power and rotor speed; otherwise, the battery is controlled not to generate power.
[0033] Preferably, the fuzzy logic control of the wind-storage system based on the wind turbine output power and rotor speed includes:
[0034] The fuzzy linguistic variable to which the wind turbine output power belongs is obtained from the per-unit value of the wind turbine output power, and the fuzzy linguistic variable to which the rotor speed belongs is obtained from the per-unit value of the rotor speed.
[0035] Based on the fuzzy linguistic variables of the wind turbine output power and the rotor speed, the fuzzy linguistic variables of the inertial response participation coefficient of the energy storage output are obtained.
[0036] The value of the inertial response participation coefficient is adjusted according to the fuzzy linguistic variable to which the inertial response participation coefficient belongs, thereby controlling the wind-storage system.
[0037] Based on the same inventive concept, this application also provides an improved frequency regulation control system for wind turbines that takes into account energy storage output mode, including a data acquisition module, a judgment module and a control module;
[0038] The data acquisition module is used to acquire the frequency of the wind turbine.
[0039] The judgment module is used to determine whether the frequency is less than a preset frequency threshold;
[0040] The control module is used to perform frequency regulation control of the wind turbine and control of the energy storage system if the frequency is less than a preset frequency threshold.
[0041] The wind turbine frequency regulation control includes: controlling the wind turbine to perform rotor kinetic energy frequency regulation control and blade pitch angle backup control based on wind speed and wind turbine rotation speed.
[0042] Preferably, the control module is specifically used to: control the wind turbine to perform rotor kinetic energy frequency regulation control and pitch angle backup control based on wind speed and wind turbine rotation speed, including:
[0043] Obtain the rotor speed and wind speed of the wind turbine;
[0044] Determine whether the rotor speed of the wind turbine is less than a preset speed threshold;
[0045] If so, there is no need to control the wind turbine to use rotor kinetic energy for frequency regulation;
[0046] Otherwise, determine whether the wind speed is less than the rated wind speed. If so, control the wind turbine to use the rotor kinetic energy for frequency regulation. Otherwise, add a backup control for the pitch angle on the basis of controlling the wind turbine to use the rotor kinetic energy for frequency regulation.
[0047] Preferably, the control of the wind turbine generator using rotor kinetic energy frequency regulation includes: controlling the wind turbine generator to perform variable coefficient integrated inertial control and virtual capacitor control, adjusting the rotor kinetic energy, and performing frequency regulation.
[0048] Preferably, the wind turbine is controlled by a variable coefficient integrated inertial control, including:
[0049] The optimal reference speed of the wind turbine is calculated using the optimal wind turbine speed calculation formula based on the wind turbine reference speed, constants related to the frequency change of the wind-storage system, and the frequency change.
[0050] Based on the calculated optimal reference speed of the wind turbine, the rotor kinetic energy of the wind turbine is adjusted, and the frequency of the wind turbine is regulated until the grid frequency returns to the rated frequency.
[0051] The change in frequency is the difference between the rated frequency and the real-time frequency.
[0052] Preferably, the virtual capacitor control method for controlling wind turbine generators includes:
[0053] The target value of the input power from the rotor-side converter to the DC-side capacitor is calculated based on the virtual capacitor, DC-side voltage, and DC-side power.
[0054] By adjusting the size of the virtual capacitor, the DC-side input power is adjusted to the target value.
[0055] Preferably, the wind turbine is controlled to control the energy storage system;
[0056] Determine whether the obtained state of charge of the energy storage system is greater than the preset minimum state of charge value;
[0057] If so, the wind-storage system is controlled by fuzzy logic based on the wind turbine's output power and rotor speed; otherwise, the battery is controlled not to generate power.
[0058] Preferably, the fuzzy logic control of the wind-storage system based on the wind turbine output power and rotor speed includes:
[0059] The fuzzy linguistic variable to which the wind turbine output power belongs is obtained from the per-unit value of the wind turbine output power, and the fuzzy linguistic variable to which the rotor speed belongs is obtained from the per-unit value of the rotor speed.
[0060] Based on the fuzzy linguistic variables of the wind turbine output power and the rotor speed, the fuzzy linguistic variables of the inertial response participation coefficient of the energy storage output are obtained.
[0061] The value of the inertial response participation coefficient is adjusted according to the fuzzy linguistic variable to which the inertial response participation coefficient belongs, thereby controlling the wind-storage system.
[0062] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0063] This invention provides an improved frequency regulation control method and system for wind turbines that takes into account energy storage output modes. The method includes: acquiring the frequency of the wind turbine; if the frequency is less than a preset frequency threshold, then performing wind turbine frequency regulation control and energy storage system control; wherein, the wind turbine frequency regulation control includes: controlling the wind turbine to perform rotor kinetic energy frequency regulation control and pitch angle reserve control based on wind speed and wind turbine rotational speed. This invention, by employing fuzzy logic control in the wind-storage joint control system, enables energy storage to dynamically determine its ability to participate in system frequency regulation based on wind speed and the wind turbine's operating state. Through this coordinated control, while fully utilizing the wind turbine's frequency regulation capability, it avoids excessive participation in system frequency regulation, fully leveraging the dynamic characteristics of energy storage, and achieving coordinated operation of wind and energy storage. Attached Figure Description
[0064] Figure 1 A flowchart of an improved frequency regulation control method for wind turbines that takes into account energy storage output mode is provided by the present invention.
[0065] Figure 2 This invention provides a block diagram for coordinated frequency regulation control of wind turbine generators;
[0066] Figure 3 This is a detailed flowchart of the wind-storage system joint participation in system frequency regulation method proposed in this invention;
[0067] Figure 4The variable coefficient integrated inertial control block diagram provided by this invention;
[0068] Figure 5 This is a system structure diagram illustrating an example of the present invention;
[0069] Figure 6 The virtual capacitor control block diagram provided by the present invention;
[0070] Figure 7 This is a fuzzy logic control block diagram of the present invention;
[0071] Figure 8(a) shows ω r Membership function;
[0072] Figure 8(b) shows p W Membership function;
[0073] Figure 8(c) shows the membership function of the output α;
[0074] Figure 9 The present invention provides a structural diagram of an improved frequency regulation control system for wind turbines that takes into account energy storage output. Detailed Implementation
[0075] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0076] Example 1:
[0077] This invention provides an improved frequency regulation control method for wind turbines that takes into account energy storage output, the specific process of which is as follows: Figure 1 As shown, it includes:
[0078] Step 1: Obtain the frequency of the wind turbine;
[0079] Step 2: Determine whether the frequency is less than a preset frequency threshold;
[0080] Step 3: If the frequency is less than the preset frequency threshold, then wind turbine frequency regulation control and energy storage system control are performed;
[0081] The wind turbine frequency regulation control includes: controlling the wind turbine to perform rotor kinetic energy frequency regulation control and blade pitch angle backup control based on wind speed and wind turbine rotation speed.
[0082] To address the issue of wind turbines participating solely in system frequency regulation control, a collaborative frequency regulation control method is proposed, comprising the following steps: First, frequency fluctuation signals and wind speed signals are acquired, and the wind speed signals are differentiated into high wind speed and low wind speed. When the actual wind speed is lower than the wind turbine's rated wind speed, a control method combining variable coefficient integrated inertial control and virtual capacitor control is adopted. When the wind speed exceeds the rated wind speed, pitch angle power backup control is added to the above combined control method. Through the coordinated operation of these three frequency regulation control methods, the problem of wind turbines participating solely in system frequency regulation can be effectively solved, and the frequency dynamic characteristics of the power grid will be greatly improved. The block diagram of the collaborative frequency regulation control method is shown below. Figure 2 As shown.
[0083] Figure 3 The flowchart shows the method for wind and energy storage systems to jointly participate in system frequency regulation. The system uses frequency data, wind speed data, rotational speed data, and state of charge to determine whether to control the wind turbine to use rotor kinetic energy for system frequency regulation control and fuzzy logic control.
[0084] The decision to add a pitch angle backup control based on wind speed data is determined in addition to the frequency regulation control of the wind turbine using rotor kinetic energy.
[0085] In step 3, the traditional integrated inertial control method for wind turbines is improved by proposing a variable coefficient integrated inertial control. Under normal circumstances, wind turbines typically operate in MPPT mode, at which point the optimal speed reference value is... Variable coefficient control introduces a frequency variation into the optimal speed control loop, using... Replace the optimal speed in The expression is:
[0086]
[0087] In the formula, K P The coefficient is related to the system frequency variation. This is the reference speed for the fan. Δf represents the optimal reference speed for the fan, and Δf represents the frequency change.
[0088] In the variable coefficient composite inertia coefficient, K is:
[0089] K = 1 + K P △f (2)
[0090] After incorporating variable coefficient integrated inertial control, the variable coefficient K changes in real time with the degree of change in system frequency, due to the reference speed of the fan. The value of the inertia coefficient depends on K, so the rotational speed will also change accordingly. The changing rotational speed is input into the wind turbine's torque control loop, causing the wind turbine's output power to change as well. Under this control method, the inertia coefficient is adjusted in real time according to the magnitude of the system disturbance, thereby enabling the wind turbine to flexibly adjust its output power according to the magnitude of the disturbance, making the wind turbine's participation in frequency regulation more flexible and targeted. As the frequency regulation process ends, the grid frequency gradually recovers. At this time, the variable coefficient inertia control stops working, and the wind turbine gradually increases its rotor speed and increases the captured wind energy. When the grid frequency finally stabilizes, the wind turbine will be in MPPT operation mode, and its control loop is as follows: Figure 4 As shown.
[0091] In step 3, the DC-side capacitor is too small to provide sufficient inertial support for the system in the DC-side inertial control method. A virtual capacitor control method is used to improve this. The relationship between the DC-side voltage and the DC-side power during system disturbance is shown in equation (3).
[0092]
[0093] In the formula, C dc For the DC capacitor of the back-to-back system, V dc It is the measured DC-side voltage (i.e., the DC capacitance C). dc (voltage across terminals), P in P is the power flowing from the rectifier into the DC-side capacitor. out The power flowing into the inverter from the DC side is as follows: Figure 5 As shown in equation (3), when the wind turbine is operating in steady state, the DC voltage remains constant. When the system is disturbed, the larger the DC-side capacitor, the smaller the voltage change rate, and the larger the DC-side capacitor can provide inertial support. Due to the limitation of the actual DC-side capacitor capacity, the inertia of this DC-side capacitor is actually small. However, after adopting the virtual capacitor control strategy, when the DC-side voltage changes, the input power can be quickly adjusted in the rotor-side inverter, as shown in equation (4). This allows the converter to quickly absorb or release additional power ΔP. vir As shown in equation (5). Moreover, the virtual capacitor can be adjusted according to the actual situation of the system, so as to provide relatively sufficient inertial support for the system without causing large fluctuations in the DC side voltage.
[0094]
[0095]
[0096] In the formula, P ref-VCC This is the new active power reference value after adopting virtual capacitor control, C. virDefined as a virtual capacitor, it is not a real capacitor, but rather an equivalent capacitor on the DC side achieved through a virtual capacitor control strategy implemented in the rotor-side inverter control loop. This takes into account the additional power ΔP provided by the virtual capacitor control strategy. vir The input power P from the rotor-side converter to the DC-side capacitor in Equation (6) represents:
[0097]
[0098] P in equation (6) in P in equation (3) in We can obtain:
[0099]
[0100] As can also be seen from (7) above, the proposed virtual capacitor control strategy can be regarded as adding a capacitor C to the actual DC side. dc Parallel virtual capacitor C vir Moreover, the virtual capacitor C vir The capacitance can be determined based on the required virtual capacitor inertia constant H. vir Adjustments were made by adding C. vir The capacitance can reduce the actual DC-side capacitance C. dc The size of the virtual capacitor control strategy not only saves costs but also reduces the size of the converter. The control block diagram of the virtual capacitor control strategy is shown below. Figure 6 As shown.
[0101] In step 3, a fuzzy logic control method was adopted for the energy storage output mode. Based on the partitioning of rotor speed and wind speed, corresponding rules were formulated for how to allocate the output of wind and energy storage in the medium-to-high wind speed range, and the output coefficient of energy storage was adjusted in real time. The fuzzy controller is as follows: Figure 7 As shown, the inputs are the rotor speed ω of the wind turbine. r With the output power P of the fan W The per-unit value of ω is used as the output, which is the inertial response participation coefficient α of the energy storage output. The output of the energy storage is determined by adjusting the coefficient α in real time through fuzzy control. The function graphs are shown in Figures 8(a)(b)(c). The input ω is... r With P W The fuzzy linguistic variables are S (small), M (medium), and L (large), and the fuzzy linguistic variables for the output coefficient α are VS (very small), S (small), M (medium), L (large), and VL (very large). The fuzzy controller changes the active power increment of the energy storage in real time according to the changes in the wind turbine output power and rotor speed, dynamically simulating the frequency response characteristics of a conventional unit. The principle of fuzzy control is: as the rotor speed ω... r Increase, PW When the value is increased, the reference coefficient α of the output energy storage inertial response should be as large as possible.
[0102] Based on the above principles, the inference table for the fuzzy controller is shown in Appendix Table 1. To verify the effectiveness of the fuzzy logic coefficients, four different wind speed conditions were selected: 10 m / s, 11 m / s, 12 m / s, and 13 m / s. Appendix Table 2 lists the output power, rotational speed, and inertial response participation coefficient α of the energy storage output under different wind speed conditions. It can be seen from the table that as the wind speed increases, the wind turbine output power increases, and this power gradually approaches the wind turbine's limit value. The available active power approaches zero, at which point the energy storage needs to output as much power as possible, therefore the energy storage output coefficient α will also increase. The calculation results shown in Table 2 are consistent with the design logic. Because the wind turbine's output power gradually approaches its limit value, the available active power decreases as the output power increases, so the energy storage needs to output as much power as possible when the wind turbine's output power is high. Based on the above principles, the inference table for the fuzzy controller is shown in Appendix Table 2.
[0103]
[0104] Table 1. Inference Table for Fuzzy Controller
[0105]
[0106] Table 2 shows examples verifying the implementation of the fuzzy logic controller.
[0107] By employing fuzzy logic control in the wind-storage integrated control system, the energy storage can dynamically determine its ability to participate in system frequency regulation based on wind speed and the operating status of the wind turbine. Through this coordinated control, the frequency regulation capability of the wind turbine is fully utilized while avoiding its excessive participation in system frequency regulation, thus giving full play to the dynamic characteristics of energy storage and achieving coordinated operation between wind and energy storage.
[0108] Example 2
[0109] This invention also provides an improved frequency regulation control system for wind turbines that takes into account energy storage output methods, such as... Figure 9 As shown, it includes a data acquisition module, a judgment module, and a control module;
[0110] The data acquisition module is used to acquire the frequency of the wind turbine.
[0111] The judgment module is used to determine whether the frequency is less than a preset frequency threshold;
[0112] The control module is used to perform frequency regulation control of the wind turbine and control of the energy storage system if the frequency is less than a preset frequency threshold.
[0113] The wind turbine frequency regulation control includes: controlling the wind turbine to perform rotor kinetic energy frequency regulation control and blade pitch angle backup control according to the wind speed and the wind turbine rotation speed;
[0114] Specifically, the control module is used to: control the wind turbine to perform rotor kinetic energy frequency regulation control and blade pitch angle backup control based on wind speed and wind turbine rotation speed, including:
[0115] Obtain the rotor speed and wind speed of the wind turbine;
[0116] Determine whether the rotor speed of the wind turbine is less than a preset speed threshold;
[0117] If so, there is no need to control the wind turbine to use rotor kinetic energy for frequency regulation;
[0118] Otherwise, determine whether the wind speed is less than the rated wind speed. If so, control the wind turbine to use the rotor kinetic energy for frequency regulation. Otherwise, add a backup control for the pitch angle on the basis of controlling the wind turbine to use the rotor kinetic energy for frequency regulation.
[0119] The control of the wind turbine generator using rotor kinetic energy frequency regulation includes: controlling the wind turbine generator to perform variable coefficient integrated inertial control and virtual capacitor control, adjusting the rotor kinetic energy, and performing frequency regulation.
[0120] Among them, the control of wind turbine units for variable coefficient integrated inertial control includes:
[0121] The optimal reference speed of the wind turbine is calculated using the optimal wind turbine speed calculation formula based on the wind turbine reference speed, constants related to the frequency change of the wind-storage system, and the frequency change.
[0122] Based on the calculated optimal reference speed of the wind turbine, the rotor kinetic energy of the wind turbine is adjusted, and the frequency of the wind turbine is controlled until the grid frequency returns to the rated frequency.
[0123] The change in frequency is the difference between the rated frequency and the real-time frequency.
[0124] The formula for calculating the optimal reference speed of the fan is:
[0125]
[0126] In the formula, K P This is a constant related to the frequency variation of the wind-storage system. The optimal reference rotor speed for the fan. Δf is the reference speed of the fan, and Δf is the difference between the rated frequency and the real-time frequency.
[0127] Among them, the virtual capacitor control method for controlling wind turbine generators includes:
[0128] The target value of the input power from the rotor-side converter to the DC-side capacitor is calculated based on the virtual capacitor, DC-side voltage, and DC-side power.
[0129] By adjusting the size of the virtual capacitor, the DC-side input power is adjusted to the target value.
[0130] The formula for calculating the target value of the input power is:
[0131]
[0132]
[0133] In the formula, P′ in C is the target value of the input power from the rotor-side converter to the DC-side capacitor. vir For virtual capacitance, ΔP vir The additional power provided by the virtual capacitor control strategy, V dc It is the measured DC-side voltage, P in This is the power flowing from the rectifier into the DC-side capacitor.
[0134] Among them, the virtual capacitor control method for controlling wind turbine generators includes:
[0135] The target value of the input power from the rotor-side converter to the DC-side capacitor is calculated based on the virtual capacitor, DC-side voltage, and DC-side power.
[0136] By adjusting the size of the virtual capacitor, the DC-side input power is adjusted to the target value.
[0137] Among them, controlling wind turbine units for energy storage system control;
[0138] Determine whether the obtained state of charge of the energy storage system is greater than the preset minimum state of charge value;
[0139] If so, the wind-storage system is controlled by fuzzy logic based on the wind turbine's output power and rotor speed; otherwise, the battery is controlled not to generate power.
[0140] The fuzzy logic control of the wind-storage system based on the wind turbine output power and rotor speed includes:
[0141] The fuzzy linguistic variable to which the wind turbine output power belongs is obtained from the per-unit value of the wind turbine output power, and the fuzzy linguistic variable to which the rotor speed belongs is obtained from the per-unit value of the rotor speed.
[0142] Based on the fuzzy linguistic variables of the wind turbine output power and the rotor speed, the fuzzy linguistic variables of the inertial response participation coefficient of the energy storage output are obtained.
[0143] The value of the inertial response participation coefficient is adjusted according to the fuzzy linguistic variable to which the inertial response participation coefficient belongs, thereby controlling the wind-storage system.
[0144] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention 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.
[0145] This invention 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 illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0146] 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.
[0147] 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 1The steps of the functions specified in one or more boxes. 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 protection scope of the claims of the present invention.
Claims
1. An improved frequency regulation control method for wind turbine generators that takes into account energy storage output, characterized in that, include: Obtain the frequency of the wind turbine; Determine whether the frequency is less than a preset frequency threshold; If the frequency is less than the preset frequency threshold, then wind turbine frequency regulation control and energy storage system control are performed. The wind turbine frequency regulation control includes: controlling the wind turbine to perform rotor kinetic energy frequency regulation control and blade pitch angle backup control according to the wind speed and the wind turbine rotation speed; The method of controlling the wind turbine generator to perform rotor kinetic energy frequency regulation control and blade pitch angle backup control based on wind speed and wind turbine generator speed includes: Obtain the rotor speed and wind speed of the wind turbine; Determine whether the rotor speed of the wind turbine is less than a preset speed threshold; If so, there is no need to control the wind turbine to use rotor kinetic energy for frequency regulation; Otherwise, determine whether the wind speed is less than the rated wind speed. If so, control the wind turbine to use the rotor kinetic energy for frequency regulation. Otherwise, add a pitch angle backup control on the basis of controlling the wind turbine to use the rotor kinetic energy for frequency regulation. Control the wind turbine generator for energy storage system control; Determine whether the obtained state of charge of the energy storage system is greater than the preset minimum state of charge value; If so, the wind-storage system is controlled by fuzzy logic based on the wind turbine's output power and rotor speed; otherwise, the battery is controlled not to generate power.
2. The method as described in claim 1, characterized in that, The control wind turbine utilizes rotation Rotor kinetic energy frequency regulation includes: controlling the wind turbine to perform variable coefficient integrated inertial control and virtual capacitor control, adjusting the rotor kinetic energy, and performing frequency regulation.
3. The method as described in claim 2, characterized in that, Controlling wind turbine generators through variable coefficient integrated inertial control includes: The optimal reference speed of the wind turbine is calculated using the optimal wind turbine speed calculation formula based on the wind turbine reference speed, constants related to the frequency change of the wind-storage system, and the frequency change. Based on the calculated optimal reference speed of the wind turbine, the rotor kinetic energy of the wind turbine is adjusted, and the frequency of the wind turbine is controlled until the grid frequency returns to the rated frequency. The change in frequency is the difference between the rated frequency and the real-time frequency.
4. The method as described in claim 3, characterized in that, The formula for calculating the optimal reference speed of the fan is: In the formula, This is a constant related to the frequency variation of the wind-storage system. The optimal reference rotor speed for the fan. This is the reference speed for the fan. This is the difference between the rated frequency and the real-time frequency.
5. The method as described in claim 2, characterized in that, The virtual capacitor control method for controlling wind turbine generators includes: The target value of the input power from the rotor-side converter to the DC-side capacitor is calculated based on the virtual capacitor, DC-side voltage, and DC-side power. By adjusting the size of the virtual capacitor, the DC-side input power is adjusted to the target value.
6. The method as described in claim 5, characterized in that, The formula for calculating the target value of the input power is: In the formula, This is the target value of the input power from the rotor-side converter to the DC-side capacitor. For virtual capacitors, Additional power provided for the virtual capacitor control strategy It is the measured DC-side voltage. .
7. The method as described in claim 1, characterized in that, The fuzzy logic control of the wind-storage system based on the wind turbine output power and rotor speed includes: The fuzzy linguistic variable to which the wind turbine output power belongs is obtained from the per-unit value of the wind turbine output power, and the fuzzy linguistic variable to which the rotor speed belongs is obtained from the per-unit value of the rotor speed. Based on the fuzzy linguistic variables of the wind turbine output power and the rotor speed, the fuzzy linguistic variables of the inertial response participation coefficient of the energy storage output are obtained. The value of the inertial response participation coefficient is adjusted according to the fuzzy linguistic variable to which the inertial response participation coefficient belongs, thereby controlling the wind-storage system.
8. An improved frequency regulation control system for wind turbine generators that takes into account energy storage output mode, characterized in that, It includes a data acquisition module, a judgment module, and a control module; The data acquisition module is used to acquire the frequency of the wind turbine. The judgment module is used to determine whether the frequency is less than a preset frequency threshold; The control module is used to perform frequency regulation control of the wind turbine and control of the energy storage system when the frequency is less than a preset frequency threshold. The wind turbine frequency regulation control includes: controlling the wind turbine to perform rotor kinetic energy frequency regulation control and blade pitch angle backup control according to the wind speed and the wind turbine rotation speed; The control module is specifically used for: Obtain the rotor speed and wind speed of the wind turbine; Determine whether the rotor speed of the wind turbine is less than a preset speed threshold; If so, there is no need to control the wind turbine to use rotor kinetic energy for frequency regulation; Otherwise, determine whether the wind speed is less than the rated wind speed. If so, control the wind turbine to use the rotor kinetic energy for frequency regulation. Otherwise, add a pitch angle backup control on the basis of controlling the wind turbine to use the rotor kinetic energy for frequency regulation. Controlling wind turbine generators for energy storage system control includes: Determine whether the obtained state of charge of the energy storage system is greater than the preset minimum state of charge value; If so, the wind-storage system is controlled by fuzzy logic based on the wind turbine's output power and rotor speed; otherwise, the battery is controlled not to generate power.
9. The system as described in claim 8, characterized in that, The control wind turbine utilizes Rotor kinetic energy frequency regulation includes: controlling the wind turbine to perform variable coefficient integrated inertial control and virtual capacitor control, adjusting the rotor kinetic energy, and performing frequency regulation.
10. The system as described in claim 9, characterized in that, Controlling wind turbine generators through variable coefficient integrated inertial control includes: The optimal reference speed of the wind turbine is calculated using the optimal wind turbine speed calculation formula based on the wind turbine reference speed, constants related to the frequency change of the wind-storage system, and the frequency change. Based on the calculated optimal reference speed of the wind turbine, the rotor kinetic energy of the wind turbine is adjusted, and the frequency of the wind turbine is controlled until the grid frequency returns to the rated frequency. The change in frequency is the difference between the rated frequency and the real-time frequency.
11. The system as described in claim 9, characterized in that, The virtual capacitor control method for controlling wind turbine generators includes: The target value of the input power from the rotor-side converter to the DC-side capacitor is calculated based on the virtual capacitor, DC-side voltage, and DC-side power. By adjusting the size of the virtual capacitor, the DC-side input power is adjusted to the target value.
12. The system as described in claim 8, characterized in that, The fuzzy logic control of the wind-storage system based on the wind turbine output power and rotor speed includes: The fuzzy linguistic variable to which the wind turbine output power belongs is obtained from the per-unit value of the wind turbine output power, and the fuzzy linguistic variable to which the rotor speed belongs is obtained from the per-unit value of the rotor speed. Based on the fuzzy linguistic variables of the wind turbine output power and the rotor speed, the fuzzy linguistic variables of the inertial response participation coefficient of the energy storage output are obtained. The value of the inertial response participation coefficient is adjusted according to the fuzzy linguistic variable to which the inertial response participation coefficient belongs, thereby controlling the wind-storage system.