A method and device for controlling the rotor of a doubly-fed wind turbine
By acquiring the kinetic energy change and wind energy capture of the doubly-fed wind turbine, the frequency regulation energy change is determined, and the rotor speed during the current frequency regulation period is controlled. This solves the problem of low rotor control accuracy of the doubly-fed wind turbine and improves the unit's operational stability and frequency regulation capability.
Patent Information
- Application Number
- CN202010236503.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-03-30
- Publication Date
- 2026-01-13
- Estimated Expiration
- 2040-03-30
AI Technical Summary
In the existing technology, the frequency controller of the doubly fed wind turbine lacks consideration of the unit's operating characteristics, resulting in low rotor control accuracy, poor unit operation stability, and difficulty in meeting the system's frequency regulation requirements.
By acquiring the kinetic energy change and wind energy capture amount from the previous frequency regulation period, the frequency regulation energy change is determined, and the rotor speed is controlled based on this. The rotor frequency converter is used to generate control signals to improve the rotor speed accuracy and stability.
This improved the control accuracy of the rotor speed of the doubly-fed wind turbine and the stability of the unit's operation, meeting the frequency regulation requirements of the power grid and enhancing the system's operational stability.
Smart Images
Figure CN111525855B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of new energy control technology, in particular to a rotor control method and device of a doubly-fed wind turbine. BACKGROUND
[0002] With the rapid development of global wind power and the rapid growth of wind turbine installed capacity, the construction of large-scale grid-connected wind farms has become an effective way to efficiently utilize wind energy. However, wind power has characteristics such as intermittency, volatility and anti-peaking, and large-scale wind power grid connection makes the system power balance and frequency modulation increasingly difficult, posing challenges to system operation control, protection and dispatching.
[0003] Doubly-fed wind turbines can participate in system frequency modulation by utilizing the rotational kinetic energy of the unit itself. When the unit operates based on maximum power tracking control, its inertia does not decrease, and it can exhibit its inertia effect by adding frequency control. The frequency control of doubly-fed wind turbines is influenced by both power grid disturbance types and unit operating conditions, but current research on frequency control of doubly-fed wind turbines mainly focuses on responding to system frequency changes, and the frequency controller lacks consideration of the operating characteristics of doubly-fed wind turbines, resulting in low precision of controlling the rotor of the unit and poor stability of the unit operation.
[0004] Therefore, when controlling the rotor of a doubly-fed wind turbine, how to fully utilize the operating characteristics of the doubly-fed wind turbine to improve the precision of controlling the rotor speed of the doubly-fed wind turbine is a problem to be solved in the field. SUMMARY
[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a rotor control method and device of a doubly-fed wind turbine, which takes into account the operating characteristics of the unit during the last frequency modulation period when controlling the rotor of the doubly-fed wind turbine, so as to improve the precision of controlling the rotor speed of the doubly-fed wind turbine and the operating stability of the unit.
[0006] The purpose of the present application is achieved by using the following technical solutions:
[0007] The present application provides a rotor control method of a doubly-fed wind turbine, which is improved in that the method comprises:
[0008] obtaining the kinetic energy change and wind energy capture of the doubly-fed wind turbine during the last frequency modulation period;
[0009] determining the frequency modulation energy change of the doubly-fed wind turbine during the last frequency modulation period according to the kinetic energy change and wind energy capture of the doubly-fed wind turbine during the last frequency modulation period;
[0010] controlling the rotor speed of the doubly-fed wind turbine during the current frequency modulation period based on the frequency modulation energy change of the doubly-fed wind turbine during the last frequency modulation period.
[0011] Preferably, the acquiring the kinetic energy variation and the wind energy capture of the doubly-fed wind turbine in the last frequency modulation period comprises:
[0012] acquiring the rotor speed of the doubly-fed wind turbine at the initial time of the last frequency modulation period, and determining the kinetic energy variation of the doubly-fed wind turbine in the last frequency modulation period according to the rotor speed of the doubly-fed wind turbine at the initial time of the last frequency modulation period;
[0013] determining the wind energy capture of the doubly-fed wind turbine in the last frequency modulation period according to the active power of the doubly-fed wind turbine in the last frequency modulation period.
[0014] Further, the rotor speed ω of the doubly-fed wind turbine at the initial time of the last frequency modulation period is acquired by the following method:
[0015] when P0≤P min , ω=ω min ;
[0016] when P min ≤P0≤P max , ω equals to the actual sampling value;
[0017] when P0≥P max , ω=ω max ;
[0018] wherein, P0 is the active power of the doubly-fed wind turbine at the initial time of the last frequency modulation period, ω min is the lower limit value of the rotor speed of the doubly-fed wind turbine, ω max is the upper limit value of the rotor speed of the doubly-fed wind turbine, P min is the lower limit value of the active power of the doubly-fed wind turbine, and P max is the upper limit value of the active power of the doubly-fed wind turbine.
[0019] Further, the determining the kinetic energy variation of the doubly-fed wind turbine in the last frequency modulation period according to the rotor speed of the doubly-fed wind turbine at the initial time of the last frequency modulation period comprises:
[0020] determining the kinetic energy variation ΔE D of the doubly-fed wind turbine in the last frequency modulation period according to the following formula:
[0021]
[0022] wherein, P D is the number of pole pairs of the doubly-fed wind turbine, J D is the total moment of inertia of the doubly-fed wind turbine, ω is the rotor speed of the doubly-fed wind turbine at the initial time of the last frequency modulation period, and ω∈[ω min , ω max ], ω min is the lower limit value of the rotor speed of the doubly-fed wind turbine, and ω maxThis represents the upper limit of the rotor speed of a doubly fed wind turbine.
[0023] Furthermore, determining the wind energy capture amount of the doubly-fed wind turbine in the previous frequency regulation period based on the active power of the doubly-fed wind turbine in the previous frequency regulation period includes:
[0024] The wind energy capture amount ΔE of the doubly-fed wind turbine during the previous frequency regulation period is determined by the following formula. P :
[0025]
[0026] In the formula, P W (t) represents the active power of the doubly-fed wind turbine at time t of the previous frequency regulation period, and P0 represents the active power of the doubly-fed wind turbine at the beginning of the previous frequency regulation period. on t is the initial time of the previous frequency modulation period. off The time at which the previous frequency modulation period ends, t∈[t on ,t off ].
[0027] Preferably, determining the frequency regulation energy change of the doubly-fed wind turbine during the previous frequency regulation period based on the change in kinetic energy and wind energy capture of the doubly-fed wind turbine during the previous frequency regulation period includes:
[0028] The frequency regulation energy change ΔE of the doubly-fed wind turbine during the previous frequency regulation period is determined by the following formula:
[0029] ΔE=ΔE D +ΔE P +M
[0030] In the formula, ΔE D ΔE represents the change in kinetic energy of the doubly-fed wind turbine during the previous frequency regulation period. P M represents the wind energy captured by the doubly-fed wind turbine during the previous frequency regulation period, and M represents the energy loss of the doubly-fed wind turbine during the previous frequency regulation period.
[0031] Preferably, controlling the rotor speed of the doubly-fed wind turbine in the current frequency regulation period based on the frequency regulation energy change of the doubly-fed wind turbine in the previous frequency regulation period includes:
[0032] The target active power value P of the doubly-fed wind turbine is determined by the following formula. ref :
[0033] P ref =P′ ref +ΔPΔE
[0034] In the formula, P′ ref ΔP is the active power reference value of the doubly-fed wind turbine, ΔP is the change in active power of the doubly-fed wind turbine, and ΔE is the change in frequency regulation energy of the doubly-fed wind turbine in the previous frequency regulation period.
[0035] The active power target value of the doubly-fed wind generator is taken as an input of a rotor frequency conversion controller, and a control signal generated by the rotor frequency conversion controller is used to control the rotor rotating speed of the doubly-fed wind generator in the current frequency modulation period.
[0036] Further, the active power reference value P' of the doubly-fed wind generator is determined according to the following formula: ref
[0037]
[0038] In the formula, ω ref is the rotor rotating speed reference value of the doubly-fed wind generator, ω is the rotor rotating speed of the doubly-fed wind generator at the initial moment of the previous frequency modulation period, K is the proportional coefficient of the rotating speed controller, and T is the integral time constant of the rotating speed controller.
[0039] Further, the active power variation ΔP of the doubly-fed wind generator is determined according to the following formula:
[0040]
[0041] In the formula, K f is the differential coefficient, and f is the grid frequency.
[0042] Based on the same inventive concept, the application further provides a rotor control device of a doubly-fed wind generator, which is improved in that the device comprises:
[0043] An acquisition unit is configured to acquire the kinetic energy variation and the wind energy capture of the doubly-fed wind generator in the previous frequency modulation period;
[0044] A determination unit is configured to determine the frequency modulation energy variation of the doubly-fed wind generator in the previous frequency modulation period according to the kinetic energy variation and the wind energy capture of the doubly-fed wind generator in the previous frequency modulation period;
[0045] A control unit is configured to control the rotor rotating speed of the doubly-fed wind generator in the current frequency modulation period based on the frequency modulation energy variation of the doubly-fed wind generator in the previous frequency modulation period.
[0046] Compared with the closest prior art, the application has the beneficial effects of:
[0047] This invention provides a rotor control method and apparatus for a doubly-fed induction generator (DFIG) wind turbine, comprising: acquiring the kinetic energy change and wind energy capture of the DFIG wind turbine during the previous frequency regulation period; determining the frequency regulation energy change of the DFIG wind turbine during the previous frequency regulation period based on the kinetic energy change and wind energy capture; and controlling the rotor speed of the DFIG wind turbine during the current frequency regulation period based on the frequency regulation energy change of the DFIG wind turbine during the previous frequency regulation period. This invention uses the frequency regulation energy change of the DFIG wind turbine as an influencing factor in the rotor control of the DFIG wind turbine, improving the accuracy of controlling the rotor speed of the DFIG wind turbine and enhancing the operational stability of the unit during speed regulation, thereby maximizing the satisfaction of the grid's frequency regulation requirements. Furthermore, when acquiring the frequency regulation energy change of the DFIG wind turbine, the rotor speed, active power, and frequency regulation losses of the unit are fully considered, laying the foundation for improving the operational stability of the unit. Attached Figure Description
[0048] Figure 1 This is a flowchart of the rotor control method for a doubly fed wind turbine generator according to the present invention;
[0049] Figure 2 This is a schematic diagram of the rotor control device for a doubly fed wind turbine of the present invention. Detailed Implementation
[0050] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0052] This invention provides a rotor control method for a doubly-fed wind turbine, such as... Figure 1 As shown, the method includes:
[0053] Obtain the kinetic energy change and wind energy capture of the doubly-fed wind turbine during the previous frequency regulation period;
[0054] The frequency regulation energy change of the doubly-fed wind turbine in the previous frequency regulation period is determined based on the change in kinetic energy and wind energy capture of the doubly-fed wind turbine in the previous frequency regulation period.
[0055] The rotor speed of the doubly fed wind turbine in the current frequency regulation period is controlled based on the change in frequency regulation energy of the doubly fed wind turbine in the previous frequency regulation period.
[0056] To more clearly illustrate the purpose of this invention, the following detailed explanation of the invention's solution is provided in conjunction with specific embodiments.
[0057] In this embodiment of the invention, obtaining the kinetic energy change and wind energy capture of the doubly-fed wind turbine during the previous frequency regulation period includes:
[0058] Obtain the rotor speed of the doubly-fed wind turbine at the beginning of the previous frequency regulation period, and determine the change in kinetic energy of the doubly-fed wind turbine during the previous frequency regulation period based on the rotor speed of the doubly-fed wind turbine at the beginning of the previous frequency regulation period.
[0059] The wind energy capture of the doubly-fed wind turbine in the previous frequency regulation period is determined based on the active power of the doubly-fed wind turbine in the previous frequency regulation period.
[0060] The rotor speed ω of the doubly-fed wind turbine at the initial moment of the previous frequency regulation period is obtained as follows:
[0061] When P0≤P min When, ω=ω min ;
[0062] When P min ≤P0≤P max When ω equals the actual sampled value;
[0063] When P0≥P max When, ω=ω max ;
[0064] Where P0 is the active power of the doubly-fed wind turbine at the beginning of the previous frequency regulation period, ω min ω represents the lower limit of the rotor speed of a doubly-fed wind turbine. max P represents the upper limit of the rotor speed of a doubly-fed wind turbine. min P is the lower limit of the active power of a doubly-fed wind turbine. max ω represents the upper limit of the active power of a doubly-fed wind turbine. max =1.2pu, ω min =0.7pu, P min The value is 0.7pu, P max It is 1.2 pu.
[0065] Specifically, the determination of the change in kinetic energy of the doubly-fed wind turbine during the previous frequency regulation period based on the rotor speed of the doubly-fed wind turbine at the initial moment of the previous frequency regulation period includes:
[0066] The change in kinetic energy ΔE of the doubly-fed wind turbine during the previous frequency regulation period is determined by the following formula. D :
[0067]
[0068] In the formula, PD J is the pole pair number of the doubly-fed wind turbine D J is the total moment of inertia of the doubly-fed wind turbine, ω is the rotor speed of the doubly-fed wind turbine at the initial time of the last frequency modulation period, ω ∈ [ω min , ω max ], ω min is the lower limit value of the rotor speed of the doubly-fed wind turbine, ω max is the upper limit value of the rotor speed of the doubly-fed wind turbine. Wherein, ω max = 1.2pu, ω min = 0.7pu.
[0069] Specifically, the wind energy capture amount of the doubly-fed wind turbine in the last frequency modulation period is determined according to the active power of the doubly-fed wind turbine in the last frequency modulation period, comprising:
[0070] The wind energy capture amount ΔE P of the doubly-fed wind turbine in the last frequency modulation period is determined according to the following formula:
[0071]
[0072] In the formula, P W (t) is the active power of the doubly-fed wind turbine at time t of the frequency modulation time in the last frequency modulation period, P0 is the active power of the doubly-fed wind turbine at the initial time of the last frequency modulation period, t on is the initial time of the last frequency modulation period, t off is the end time of the last frequency modulation period, t ∈ [t on , t off ].
[0073] In the embodiment of the application, the frequency modulation energy change amount of the doubly-fed wind turbine in the last frequency modulation period is determined according to the kinetic energy change amount and the wind energy capture amount of the doubly-fed wind turbine in the last frequency modulation period, comprising:
[0074] The frequency modulation energy change amount ΔE of the doubly-fed wind turbine in the last frequency modulation period is determined according to the following formula:
[0075] ΔE = ΔE D + ΔE P + M
[0076] In the formula, ΔE D is the kinetic energy change amount of the doubly-fed wind turbine in the last frequency modulation period, ΔE P is the wind energy capture amount of the doubly-fed wind turbine in the last frequency modulation period, and M is the energy loss of the doubly-fed wind turbine in the last frequency modulation period.
[0077] In the embodiment of the application, the rotor speed of the doubly-fed wind turbine in the current frequency modulation period is controlled based on the frequency modulation energy change amount of the doubly-fed wind turbine in the last frequency modulation period, comprising:
[0078] The target active power value P of the doubly-fed wind turbine is determined by the following formula. ref :
[0079] P ref =P′ ref +ΔPΔE
[0080] In the formula, P′ ref ΔP is the active power reference value of the doubly-fed wind turbine, ΔP is the change in active power of the doubly-fed wind turbine, and ΔE is the change in frequency regulation energy of the doubly-fed wind turbine in the previous frequency regulation period.
[0081] The active power target value of the doubly fed wind turbine is used as the input of the rotor frequency converter, and the control signal generated by the rotor frequency converter is used to control the rotor speed of the doubly fed wind turbine during the current frequency regulation period.
[0082] Specifically, the active power reference value P′ of the doubly-fed wind turbine is determined by the following formula. ref :
[0083]
[0084] In the formula, ω ref ω is the reference value of the rotor speed of the doubly fed wind turbine, K is the rotor speed of the doubly fed wind turbine at the beginning of the previous frequency regulation period, T is the proportional coefficient of the speed controller, and T is the integral time constant of the speed controller.
[0085] Specifically, the change in active power ΔP of the doubly-fed wind turbine is determined by the following formula:
[0086]
[0087] In the formula, K f is the differential coefficient, and f is the power grid frequency.
[0088] In an embodiment of the present invention, the active power target value of the doubly-fed wind turbine is used as the input of the rotor frequency converter, and the control signal generated by the rotor frequency converter is used to control the rotor speed of the doubly-fed wind turbine during the current frequency regulation period. Specifically, the active power target value of the doubly-fed wind turbine obtained by the present invention is used as the active power target value P in the document "Research on the Interaction Principle and System Oscillation Characteristics of Doubly-Fed Wind Turbine and Static Var Generator" published in the February 2017 issue of Power System Technology, Volume 41, Issue 2. ref This enables control of the rotor speed of the doubly fed wind turbine during the current frequency regulation period.
[0089] Based on the same inventive concept, the present invention also provides a rotor control device for a doubly fed wind turbine, such as... Figure 2 As shown, the device includes:
[0090] an acquisition unit, configured to acquire kinetic energy variation and wind energy capture of the doubly-fed wind turbine in the previous frequency modulation period;
[0091] a determination unit, configured to determine frequency modulation energy variation of the doubly-fed wind turbine in the previous frequency modulation period according to the kinetic energy variation and the wind energy capture of the doubly-fed wind turbine in the previous frequency modulation period;
[0092] a control unit, configured to control rotor speed of the doubly-fed wind turbine in the current frequency modulation period based on the frequency modulation energy variation of the doubly-fed wind turbine in the previous frequency modulation period.
[0093] In the embodiment of the present application, the acquisition of the kinetic energy variation and the wind energy capture of the doubly-fed wind turbine in the previous frequency modulation period comprises:
[0094] acquiring rotor speed of the doubly-fed wind turbine at the initial moment of the previous frequency modulation period, and determining the kinetic energy variation of the doubly-fed wind turbine in the previous frequency modulation period according to the rotor speed of the doubly-fed wind turbine at the initial moment of the previous frequency modulation period;
[0095] determining the wind energy capture of the doubly-fed wind turbine in the previous frequency modulation period according to active power of the doubly-fed wind turbine in the previous frequency modulation period.
[0096] wherein, the rotor speed ω of the doubly-fed wind turbine at the initial moment of the previous frequency modulation period is acquired by the following method:
[0097] when P0≤P min , ω=ω min ;
[0098] when P min ≤P0≤P max , ω is equal to the actual sampling value;
[0099] when P0≥P max , ω=ω max ;
[0100] wherein, P0 is the active power of the doubly-fed wind turbine at the initial moment of the previous frequency modulation period, ω min is the lower limit value of the rotor speed of the doubly-fed wind turbine, ω max is the upper limit value of the rotor speed of the doubly-fed wind turbine, P min is the lower limit value of the active power of the doubly-fed wind turbine, P max is the upper limit value of the active power of the doubly-fed wind turbine, ω max =1.2pu, ω min =0.7puP min =0.7pu, P max =1.2pu.
[0101] Specifically, the determination of the kinetic energy change amount of the doubly-fed wind turbine in the last frequency modulation period according to the rotor speed of the doubly-fed wind turbine at the initial time of the last frequency modulation period comprises:
[0102] The kinetic energy change amount of the doubly-fed wind turbine in the last frequency modulation period is determined according to the following formula: D :
[0103]
[0104] In the formula, P D is the number of pole pairs of the doubly-fed wind turbine, J D is the total moment of inertia of the doubly-fed wind turbine, ω is the rotor speed of the doubly-fed wind turbine at the initial time of the last frequency modulation period, ω ∈ [ω min , ω max ], ω min is the lower limit value of the rotor speed of the doubly-fed wind turbine, and ω max is the upper limit value of the rotor speed of the doubly-fed wind turbine.
[0105] Specifically, the determination of the wind energy capture amount of the doubly-fed wind turbine in the last frequency modulation period according to the active power of the doubly-fed wind turbine in the last frequency modulation period comprises:
[0106] The wind energy capture amount of the doubly-fed wind turbine in the last frequency modulation period is determined according to the following formula: P :
[0107]
[0108] In the formula, P W (t) is the active power of the doubly-fed wind turbine at time t of the frequency modulation time in the last frequency modulation period, P0 is the active power of the doubly-fed wind turbine at the initial time of the last frequency modulation period, t on is the initial time of the last frequency modulation period, t off is the end time of the last frequency modulation period, and t ∈ [t on , t off ].
[0109] In the embodiment of the application, the determination of the frequency modulation energy change amount of the doubly-fed wind turbine in the last frequency modulation period according to the kinetic energy change amount and the wind energy capture amount of the doubly-fed wind turbine in the last frequency modulation period comprises:
[0110] The frequency modulation energy change amount of the doubly-fed wind turbine in the last frequency modulation period is determined according to the following formula:
[0111] ΔE = ΔE D + ΔE P + M
[0112] In the formula, ΔE D is the kinetic energy change amount of the doubly-fed wind turbine in the last frequency modulation period, ΔE PM represents the wind energy captured by the doubly-fed wind turbine during the previous frequency regulation period, and M represents the energy loss of the doubly-fed wind turbine during the previous frequency regulation period.
[0113] In an embodiment of the present invention, the above-mentioned control of the rotor speed of the doubly-fed wind turbine in the current frequency regulation period based on the frequency regulation energy change of the doubly-fed wind turbine in the previous frequency regulation period includes:
[0114] The target active power value P of the doubly-fed wind turbine is determined by the following formula. ref :
[0115] P ref =P′ ref +ΔPΔE
[0116] In the formula, P′ ref ΔP is the active power reference value of the doubly-fed wind turbine, ΔP is the change in active power of the doubly-fed wind turbine, and ΔE is the change in frequency regulation energy of the doubly-fed wind turbine in the previous frequency regulation period.
[0117] The active power target value of the doubly fed wind turbine is used as the input of the rotor frequency converter, and the control signal generated by the rotor frequency converter is used to control the rotor speed of the doubly fed wind turbine during the current frequency regulation period.
[0118] Specifically, the active power reference value P′ of the doubly-fed wind turbine is determined by the following formula. ref :
[0119]
[0120] In the formula, ω ref ω is the reference value of the rotor speed of the doubly fed wind turbine, K is the rotor speed of the doubly fed wind turbine at the beginning of the previous frequency regulation period, T is the proportional coefficient of the speed controller, and T is the integral time constant of the speed controller.
[0121] Specifically, the change in active power ΔP of the doubly-fed wind turbine is determined by the following formula:
[0122]
[0123] In the formula, K f is the differential coefficient, and f is the power grid frequency.
[0124] In summary, the application provides a rotor control method and device for a doubly-fed wind turbine, comprising: obtaining kinetic energy variation and wind energy capture of the doubly-fed wind turbine in a previous frequency modulation period; determining frequency modulation energy variation of the doubly-fed wind turbine in the previous frequency modulation period according to the kinetic energy variation and the wind energy capture of the doubly-fed wind turbine in the previous frequency modulation period; and controlling rotor speed of the doubly-fed wind turbine in a current frequency modulation period based on the frequency modulation energy variation of the doubly-fed wind turbine in the previous frequency modulation period. The application takes the frequency modulation energy variation of the doubly-fed wind turbine as an influencing factor when controlling the rotor of the doubly-fed wind turbine, thereby improving the accuracy of controlling the rotor speed of the doubly-fed wind turbine and the operation stability in the speed regulation process of the unit, and further meeting the frequency modulation needs of the power grid to the maximum extent. When obtaining the frequency modulation energy variation of the doubly-fed wind turbine, the rotor speed, active power and frequency modulation loss of the unit are fully considered, thereby laying a foundation for improving the operation stability of the unit.
[0125] Those skilled in the art will appreciate that embodiments of the application can be supplied as a method, a system, or a computer program product. Accordingly, the application can be embodied in the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the application can be embodied in the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk memory, CD-ROMs, optical storage media, etc.) having computer usable program code embodied thereon.
[0126] The present application is described with reference to the flowcharts and / or block diagrams according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as combinations of flows and / or blocks in the flowcharts 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, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus generate a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in a flow or multiple flows and / or blocks Figure 1 The functions specified in a flow or multiple flows and / or blocks
[0127] These computer program instructions can also be stored in a computer-readable memory that can direct the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including instruction means, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in a flow or multiple flows and / or blocks Figure 1 The functions specified in a flow or multiple flows and / or blocks
[0128] These computer program instructions can also be loaded into a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 one or more flowcharts and / or blocks
[0129] Finally, it should be noted that the above-mentioned embodiments are merely used to illustrate the technical solutions of the present application, rather than limit the technical solutions of the present application. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.
Claims
1. A method of rotor control for a doubly-fed wind turbine generator, characterized by, The method comprises: acquiring kinetic energy variation and wind energy capture of the doubly-fed wind turbine in the last frequency modulation period; determining frequency modulation energy variation of the doubly-fed wind turbine in the last frequency modulation period according to the kinetic energy variation and the wind energy capture of the doubly-fed wind turbine in the last frequency modulation period; controlling rotor speed of the doubly-fed wind turbine in the current frequency modulation period based on the frequency modulation energy variation of the doubly-fed wind turbine in the last frequency modulation period; the controlling rotor speed of the doubly-fed wind turbine in the current frequency modulation period based on the frequency modulation energy variation of the doubly-fed wind turbine in the last frequency modulation period comprises: The active power target value P of the doubly-fed wind power generator is determined according to the following formula ref : P ref = P' ref + ΔPΔE In the formula, P′ ref ΔP is the active power reference value of the doubly-fed wind turbine, ΔP is the change in active power of the doubly-fed wind turbine, and ΔE is the change in frequency regulation energy of the doubly-fed wind turbine in the previous frequency regulation period. taking the active power target value of the doubly-fed wind turbine as input of a rotor frequency converter, and controlling rotor speed of the doubly-fed wind turbine in the current frequency modulation period by using a control signal generated by the rotor frequency converter; The active power reference value P' of the doubly-fed wind power unit is determined according to the following formula ref : In the formula, ω ref is the rotor speed reference value of the doubly-fed wind turbine, ω is the rotor speed of the doubly-fed wind turbine at the initial moment of the last frequency modulation period, K is the proportional coefficient of the speed controller, and T is the integral time constant of the speed controller. determining active power variation ΔP of the doubly-fed wind turbine according to the following formula: where K f is the differential coefficient and f is the grid frequency.
2. The method of claim 1, wherein, the acquiring kinetic energy variation and wind energy capture of the doubly-fed wind turbine in the last frequency modulation period comprises: acquiring rotor speed of the doubly-fed wind turbine at the initial moment of the last frequency modulation period, and determining kinetic energy variation of the doubly-fed wind turbine in the last frequency modulation period according to the rotor speed of the doubly-fed wind turbine at the initial moment of the last frequency modulation period; determining wind energy capture of the doubly-fed wind turbine in the last frequency modulation period according to active power of the doubly-fed wind turbine in the last frequency modulation period.
3. The method of claim 2, wherein, the rotor speed of the doubly-fed wind turbine at the initial moment of the last frequency modulation period ω is acquired according to the following method: When P0≤P min , ω = ω min ; When P min <P0<P max ω is equal to the actual sample value; When P0≥P max , ω = ω max ; wherein P0 is the active power of the doubly-fed wind generator at the initial time of the last frequency modulation period, ω min is the lower limit of the rotor speed of the doubly-fed wind generator, ω max is the upper limit of the rotor speed of the doubly-fed wind generator, P min is the lower limit of the active power of the doubly-fed wind generator, P max is the upper limit of the active power of the doubly-fed wind generator.
4. The method of claim 2, wherein, the determining kinetic energy variation of the doubly-fed wind turbine in the last frequency modulation period according to the rotor speed of the doubly-fed wind turbine at the initial moment of the last frequency modulation period comprises: The kinetic energy change ΔE of the doubly-fed wind power generator in the last frequency modulation period is determined according to the following formula D : In the formula, P D is the number of pole pairs of the doubly-fed wind turbine, J D is the total moment of inertia of the doubly-fed wind turbine, ω is the rotor speed of the doubly-fed wind turbine at the initial time of the last frequency modulation period, ω ∈ [ω min , ω max ], ω min is the lower limit value of the rotor speed of the doubly-fed wind turbine, and ω max is the upper limit value of the rotor speed of the doubly-fed wind turbine.
5. The method of claim 2, wherein, the determining wind energy capture of the doubly-fed wind turbine in the last frequency modulation period according to active power of the doubly-fed wind turbine in the last frequency modulation period comprises: The wind energy capture AE of the doubly-fed wind turbine in the previous frequency modulation period is determined according to the following formula P : In the formula, P W (t) is the active power of the doubly-fed wind generator at the frequency modulation time t in the last frequency modulation period, P0 is the active power of the doubly-fed wind generator at the initial time in the last frequency modulation period, t on is the initial time in the last frequency modulation period, t off is the end time in the last frequency modulation period, and t ∈ [t on , t off ].
6. The method of claim 1, wherein, the determining frequency modulation energy variation of the doubly-fed wind turbine in the last frequency modulation period according to the kinetic energy variation and the wind energy capture of the doubly-fed wind turbine in the last frequency modulation period comprises: determining frequency modulation energy variation ΔE of the doubly-fed wind turbine in the last frequency modulation period according to the following formula: ΔE = ΔE D + ΔE P + M wherein ΔE D is the kinetic energy change of the DFIG wind turbine in the previous frequency regulation period, ΔE P is the wind energy capture of the DFIG wind turbine in the previous frequency regulation period, M is the energy loss of the DFIG wind turbine in the previous frequency regulation period.
7. A doubly-fed wind turbine generator rotor control device, characterised in that, The device comprises: an acquiring unit configured to acquire kinetic energy variation and wind energy capture of the doubly-fed wind turbine in the last frequency modulation period; a determining unit configured to determine frequency modulation energy variation of the doubly-fed wind turbine in the last frequency modulation period according to the kinetic energy variation and the wind energy capture of the doubly-fed wind turbine in the last frequency modulation period; a controlling unit configured to control rotor speed of the doubly-fed wind turbine in the current frequency modulation period based on the frequency modulation energy variation of the doubly-fed wind turbine in the last frequency modulation period; the controlling unit is specifically configured to: The active power target value P of the doubly-fed wind power generator is determined according to the following formula ref : P ref = P' ref + ΔPΔE In the formula, P′ ref ΔP is the active power reference value of the doubly-fed wind turbine, ΔP is the change in active power of the doubly-fed wind turbine, and ΔE is the change in frequency regulation energy of the doubly-fed wind turbine in the previous frequency regulation period. take the active power target value of the doubly-fed wind turbine as input of a rotor frequency converter, and control rotor speed of the doubly-fed wind turbine in the current frequency modulation period by using a control signal generated by the rotor frequency converter; The active power reference value P' of the doubly-fed wind power unit is determined according to the following formula ref : In the formula, ω ref is the rotor speed reference value of the doubly-fed wind turbine, ω is the rotor speed of the doubly-fed wind turbine at the initial moment of the last frequency modulation period, K is the proportional coefficient of the speed controller, and T is the integral time constant of the speed controller. determine active power variation ΔP of the doubly-fed wind turbine according to the following formula: where K f is the differential coefficient and f is the grid frequency.