Frequency modulation control method and device for wind storage combined system

Abstract

The invention provides a wind storage combined system frequency modulation control method and device, and the method comprises the steps: carrying out the fuzzy calculation through a first fuzzy logic controller according to the frequency offset and the frequency change rate, and generating the total active power increment of a wind storage combined system; performing fuzzy calculation through a second fuzzy logic controller according to the operation parameters of the wind turbine generator and the current charge state of the energy storage system, and generating a frequency modulation participation coefficient of the wind turbine generator; performing frequency modulation control on the wind storage combined system according to the frequency modulation participation coefficient and the total active power increment of the wind turbine generator, and formulating a wind storage combined frequency modulation control strategy by analyzing the controllable potential of the wind storage combined system and describing a calculation method of a total output power and a power distribution principle of the wind storage combined system based on a fuzzy control theory. And the frequency modulation capability and stability are improved, so that the wind turbine generator can provide active standby support, thereby ensuring stable operation of the system.

Description

Technical Field

[0001] The present invention relates to the field of computer technology, and in particular to a frequency modulation control method and device for a wind-storage combined system. Background Art

[0002] With the grid connection of new energy power generation resources providing sufficient frequency regulation capacity for the system, it has become the norm to tap the frequency regulation potential of wind turbines through additional frequency control. However, the output power of wind turbines is subject to many restrictions of the external environment and its own equipment, exposing the shortcomings of wind turbines' insufficient ability to participate in system frequency regulation alone, mainly including the following aspects. First, wind turbines usually operate at the optimal working point. At this time, wind turbines in the maximum power point tracking (MPPT) mode cannot provide active backup support; second, the output of wind turbines is affected by wind speed, especially at extreme wind speeds. The output power and blade control of wind turbines will be strongly restricted, and even lose the frequency regulation capability; third, the output of wind turbines is unpredictable and volatile, and wind turbines often contain frequency-sensitive components, which may cause the frequency regulation process to be withdrawn midway, further causing system failures. In the related technology, the power allocation problem of new energy resources with additional energy storage is carried out. The system frequency regulation output is calculated based on the given maximum spare capacity space to formulate a coordinated control strategy. Although this method can theoretically achieve short-term frequency regulation tasks, from the perspective of the overall frequency regulation control framework, the ideal assumption cannot meet the needs in practical applications due to the lack of analysis of the actual controllable potential of the spare capacity. Summary of the invention

[0003] One object of the present invention is to provide a frequency regulation control method for a wind-storage combined system, by analyzing the controllable potential of the wind-storage combined system and describing the calculation method of the total output power and power allocation principle of the wind-storage combined system based on fuzzy control theory, formulating a wind-storage combined frequency regulation control strategy, improving the frequency regulation capability and stability, so that the wind turbines can provide active standby support, thereby ensuring the stable operation of the system. Another object of the present invention is to provide a frequency regulation control device for a wind-storage combined system. Another object of the present invention is to provide a computer-readable medium. Still another object of the present invention is to provide a computer device.

[0004] In order to achieve the above objectives, the present invention discloses a frequency regulation control method for a wind-storage combined system, comprising:

[0005] Obtaining the frequency offset and frequency change rate of the wind-storage combined system after disturbance, where the wind-storage combined system includes a wind turbine and an energy storage system;

[0006] By using a preset first fuzzy logic controller, according to a first membership function and a first fuzzy logic rule table, fuzzy calculation is performed according to the frequency offset and the frequency change rate to generate a total active power increment of the wind-storage combined system;

[0007] By using a preset second fuzzy logic controller, according to a second membership function and a second fuzzy logic rule table, fuzzy calculation is performed according to the wind turbine operating parameters and the current charge state of the energy storage system to generate a wind turbine frequency modulation participation coefficient;

[0008] The frequency regulation of the wind-storage combined system is controlled according to the frequency regulation participation coefficient of the wind turbines and the total active power increment.

[0009] Preferably, the method further comprises:

[0010] Get the wind speed of the wind turbine;

[0011] According to the pre-divided wind speed range and the wind speed of the wind turbine, determine whether the wind turbine meets the load reduction operation conditions;

[0012] If so, the wind turbine is operated at reduced load according to the load reduction operation strategy.

[0013] Preferably, the method further comprises:

[0014] Obtain the initial state of charge, rated capacity and rated power of the energy storage system;

[0015] Generate a current state of charge based on the initial state of charge, rated capacity and rated power;

[0016] According to the current state of charge, determine whether the energy storage system meets the conditions for joint frequency regulation;

[0017] If so, continue to execute the step of obtaining the frequency offset and frequency change rate of the wind-storage combined system after the disturbance occurs, and the wind-storage combined system includes a wind turbine and an energy storage system.

[0018] Preferably, the wind turbine operating parameters include speed parameters and power parameters;

[0019] Through the preset second fuzzy logic controller, according to the second membership function and the second fuzzy logic rule table, fuzzy calculation is performed according to the wind turbine operating parameters and the current charge state of the energy storage system to generate the wind turbine frequency regulation participation coefficient, including:

[0020] Generate the additional power capacity of the wind turbine according to the speed parameters and power parameters;

[0021] Generate the additional power capacity of the energy storage system based on the current state of charge and frequency offset;

[0022] The preset second fuzzy logic controller performs fuzzy calculation on the additional power capacity of the wind turbine and the additional power capacity of the energy storage system according to the second membership function and the second fuzzy logic rule table, and generates the frequency regulation participation coefficient of the wind turbine.

[0023] Preferably, generating the additional power capability of the wind turbine generator set according to the speed parameter and the power parameter includes:

[0024] Generate speed frequency modulation capability according to speed parameters;

[0025] Generate power frequency modulation capability based on power parameters;

[0026] Compare the speed frequency regulation capability and power frequency regulation capability to determine the additional power capacity of the wind turbine.

[0027] Preferably, the frequency regulation control of the wind-storage combined system is performed according to the frequency regulation participation coefficient of the wind turbine generator set and the total active power increment, including:

[0028] Generate the wind turbine active power increment according to the wind turbine frequency regulation participation coefficient and the total active power increment, and distribute the wind turbine active power increment to the wind turbine;

[0029] According to the frequency regulation participation coefficient of the wind turbine, determine the frequency regulation participation coefficient of the energy storage system;

[0030] According to the frequency regulation participation coefficient of the energy storage system and the total active power increment, the active power increment of the energy storage system is generated, and the active power increment of the energy storage system is distributed to the energy storage system.

[0031] The present invention also discloses a frequency modulation control device for a wind-storage combined system, comprising:

[0032] A frequency parameter acquisition unit, used to acquire a frequency offset and a frequency change rate after a disturbance occurs in the wind-storage combined system, wherein the wind-storage combined system includes a wind turbine and an energy storage system;

[0033] A first fuzzy calculation unit is used to generate a total active power increment of the wind-storage combined system by performing fuzzy calculation according to a first membership function and a first fuzzy logic rule table through a preset first fuzzy logic controller according to a frequency offset and a frequency change rate;

[0034] A second fuzzy calculation unit is used to generate a frequency regulation participation coefficient of the wind turbine set by performing fuzzy calculation according to the second membership function and the second fuzzy logic rule table based on the wind turbine set operating parameters and the current charge state of the energy storage system through a preset second fuzzy logic controller;

[0035] The frequency control unit is used to perform frequency control on the wind-storage combined system according to the frequency participation coefficient of the wind turbine set and the total active power increment.

[0036] Preferably, the device further comprises:

[0037] A wind speed acquisition unit, used to acquire the wind speed of the wind turbine;

[0038] A load shedding judgment unit is used to judge whether the wind turbine generator set meets the load shedding operation conditions according to the wind speed of the wind turbine generator set in accordance with the pre-divided wind speed interval;

[0039] The load reduction operation unit is used to perform load reduction operation on the wind turbine set according to the load reduction operation strategy.

[0040] Preferably, the device further comprises:

[0041] An energy storage parameter acquisition unit, used to obtain the initial state of charge, rated capacity and rated power of the energy storage system;

[0042] A state of charge generating unit, used to generate a current state of charge according to an initial state of charge, a rated capacity and a rated power;

[0043] The frequency regulation judgment unit is used to judge whether the energy storage system meets the joint frequency regulation conditions according to the current charge state; if so, the trigger frequency parameter acquisition unit continues to execute the steps of obtaining the frequency offset and frequency change rate after the disturbance occurs in the wind-storage combined system, and the wind-storage combined system includes a wind turbine and an energy storage system.

[0044] Preferably, the wind turbine operating parameters include speed parameters and power parameters;

[0045] The second fuzzy calculation unit is specifically used to generate the additional power capacity of the wind turbine according to the speed parameter and the power parameter; generate the additional power capacity of the energy storage system according to the current state of charge and the frequency offset; the preset second fuzzy logic controller performs fuzzy calculation on the additional power capacity of the wind turbine and the additional power capacity of the energy storage system according to the second membership function and the second fuzzy logic rule table, and generates the frequency regulation participation coefficient of the wind turbine.

[0046] Preferably, the second fuzzy calculation unit is specifically used to generate a speed frequency regulation capability according to a speed parameter; generate a power frequency regulation capability according to a power parameter; compare the speed frequency regulation capability and the power frequency regulation capability to determine the additional power capacity of the wind turbine set.

[0047] Preferably, the frequency regulation control unit is specifically used to generate the active power increment of the wind turbine group according to the frequency regulation participation coefficient of the wind turbine group and the total active power increment, and distribute the active power increment of the wind turbine group to the wind turbine group; determine the frequency regulation participation coefficient of the energy storage system according to the frequency regulation participation coefficient of the wind turbine group; generate the active power increment of the energy storage system according to the frequency regulation participation coefficient of the energy storage system and the total active power increment, and distribute the active power increment of the energy storage system to the energy storage system.

[0048] The present invention also discloses a computer-readable medium on which a computer program is stored. When the program is executed by a processor, the method described above is implemented.

[0049] The present invention also discloses a computer device, including a memory and a processor, wherein the memory is used to store information including program instructions, the processor is used to control the execution of program instructions, and the processor implements the above method when executing the program.

[0050] The present invention also discloses a computer program product, including a computer program / instruction, and the method described above is implemented when the computer program / instruction is executed by a processor.

[0051] The present invention obtains the frequency offset and frequency change rate of a wind-storage combined system after a disturbance occurs, wherein the wind-storage combined system includes a wind turbine and an energy storage system; through a preset first fuzzy logic controller, fuzzy calculation is performed according to the frequency offset and the frequency change rate according to a first membership function and a first fuzzy logic rule table, to generate a total active power increment of the wind-storage combined system; through a preset second fuzzy logic controller, fuzzy calculation is performed according to the wind turbine operating parameters and the current charge state of the energy storage system according to a second membership function and a second fuzzy logic rule table, to generate a frequency regulation participation coefficient of the wind turbine; according to the frequency regulation participation coefficient of the wind turbine and the total active power increment, frequency regulation control is performed on the wind-storage combined system, and a controllable potential of the wind-storage combined system is analyzed, and a calculation method for describing the total output power and power allocation principle of the wind-storage combined system based on fuzzy control theory is formulated, a wind-storage combined frequency regulation control strategy is formulated, the frequency regulation capability and stability are improved, and the wind turbine can provide active standby support, thereby ensuring stable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 A flow chart of a frequency regulation control method for a wind-storage combined system provided by an embodiment of the present invention;

[0054] Figure 2 A flow chart of another frequency regulation control method for a wind-storage combined system provided by an embodiment of the present invention;

[0055] Figure 3 A schematic diagram of a frequency offset membership function curve provided by an embodiment of the present invention;

[0056] Figure 4 A schematic diagram of a frequency change rate membership function curve provided by an embodiment of the present invention;

[0057] Figure 5 A schematic diagram of a curve of a total active power increment membership function provided by an embodiment of the present invention;

[0058] Figure 6 A schematic diagram of a curve of a membership function of the additional power capability of a wind turbine provided by an embodiment of the present invention;

[0059] Figure 7 A schematic diagram of a curve of a membership function of the incremental power capability of an energy storage system provided in an embodiment of the present invention;

[0060] Figure 8 A curve diagram of a membership function of a wind turbine frequency regulation participation coefficient provided by an embodiment of the present invention;

[0061] Fig. 9 This is a schematic diagram of frequency variation of a four-machine two-zone system under normal wind speed;

[0062] Fig.10 This is a schematic diagram of the change in additional power of a four-machine two-zone system under normal wind speed;

[0063] Fig.11 This is a schematic diagram of frequency variation of a four-machine two-zone system under extreme wind speeds;

[0064] Fig.12 This is a schematic diagram of the change in additional power of a four-machine two-zone system under extreme wind speeds;

[0065] Fig.13 It is a schematic diagram of the frequency change of the IEEE39 node system under normal wind speed;

[0066] Fig.14 This is a schematic diagram of the additional power change of the IEEE39 node system under normal wind speed;

[0067] Fig.15 Schematic diagram of frequency variation of IEEE39-node system under extreme wind speed;

[0068] Fig.16 It is a schematic diagram of the change of the additional power of the IEEE39 node system under the positive extreme wind speed;

[0069] Fig.17 A schematic diagram of the structure of a frequency regulation control device for a wind-storage combined system provided by an embodiment of the present invention;

[0070] Fig.18A schematic diagram of the structure of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0071] 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.

[0072] It should be noted that the frequency regulation control method and device for a wind-storage combined system disclosed in the present application can be used in the field of artificial intelligence technology, and can also be used in any field outside the field of artificial intelligence technology. The application field of the frequency regulation control method and device for a wind-storage combined system disclosed in the present application is not limited.

[0073] In order to facilitate the understanding of the technical solution provided by the present application, the relevant contents of the technical solution of the present application are first described below. The present invention uses wind power as a representative of new energy control resources, analyzes the controllable potential of the wind-storage combined system, and describes the calculation method of the total output power and power allocation principle of the wind-storage combined system based on fuzzy control theory, and formulates a wind-storage combined frequency regulation control strategy, which can make up for the insufficient ability of wind turbines to participate in system frequency regulation alone. Doubly Fed Induction Generator (DFIG) is a type of generator widely used in wind power generation systems. The maximum active power and optimal speed of wind turbines corresponding to different wind speeds are significantly different, and at the same time affect the optimal speed of wind turbines under MPPT mode operation. Therefore, in preventive control, it is necessary to distinguish the operating status of the DFIG unit, and only reduce the load of the DFIG unit that meets the requirements to ensure that when a frequency offset occurs after a disturbance, the DFIG unit in load reduction operation can quickly participate in system frequency regulation through virtual inertial response and droop control. Therefore, it is necessary to consider different wind speed scenarios. Considering that the operating speed of DFIG units is usually 0.7-1.2 pu, in order to give full play to the potential of spare capacity within a limited speed range, it is necessary to perform wind speed zoning to achieve controllable potential analysis. The controllable potential analysis of the energy storage system mainly depends on the state of charge (SOC) of the energy storage system. Only within the normal working range can it provide sufficient support for the DFIG unit to participate in frequency regulation.

[0074] The following takes the frequency regulation control device of the wind-storage combined system as an example to illustrate the implementation process of the frequency regulation control method of the wind-storage combined system provided by the embodiment of the present invention. It is understandable that the execution subject of the frequency regulation control method of the wind-storage combined system provided by the embodiment of the present invention includes but is not limited to the frequency regulation control device of the wind-storage combined system.

[0075] Figure 1 A flow chart of a frequency regulation control method for a wind-storage combined system provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the method includes:

[0076] Step 101: Obtain the frequency offset and frequency change rate of the wind-storage combined system after a disturbance occurs.

[0077] In an embodiment of the present invention, the wind-storage combined system includes a wind turbine and an energy storage system.

[0078] Step 102: Through the preset first fuzzy logic controller (FCL1), according to the first membership function and the first fuzzy logic rule table, fuzzy calculation is performed according to the frequency offset and the frequency change rate to generate the total active power increment of the wind-storage combined system.

[0079] In the embodiment of the present invention, the severity of the frequency offset and the urgency of the frequency fluctuation rate are described in FCL 1, and the total active power increment of the wind-storage combined system is output under controllable potential according to the frequency safety requirements.

[0080] Step 103: Perform fuzzy calculation according to the second membership function and the second fuzzy logic rule table, the wind turbine operating parameters and the current state of charge of the energy storage system to generate a wind turbine frequency regulation participation coefficient through a preset second fuzzy logic controller (FCL 2).

[0081] In the embodiment of the present invention, the wind turbine operating parameters include speed parameters and power parameters.

[0082] In the embodiment of the present invention, the operating conditions of the wind turbine and the energy storage system are monitored in real time in FCL 2, and the allocation of the total active power increment between the wind turbine and the energy storage system is determined based on the comparison of the remaining additional power capacity, and the wind turbine frequency regulation participation coefficient is output.

[0083] Step 104: Perform frequency regulation control on the wind-storage combined system according to the frequency regulation participation coefficient of the wind turbine generator set and the total active power increment.

[0084] In the technical solution provided by the embodiment of the present invention, the frequency offset and frequency change rate of the wind-storage combined system after a disturbance occurs are obtained, and the wind-storage combined system includes a wind turbine and an energy storage system; through a preset first fuzzy logic controller, fuzzy calculation is performed according to the frequency offset and the frequency change rate according to the first membership function and the first fuzzy logic rule table, and the total active power increment of the wind-storage combined system is generated; through a preset second fuzzy logic controller, fuzzy calculation is performed according to the wind turbine operating parameters and the current charge state of the energy storage system according to the second membership function and the second fuzzy logic rule table, and the wind turbine frequency regulation participation coefficient is generated; according to the wind turbine frequency regulation participation coefficient and the total active power increment, the wind-storage combined system is frequency-controlled, and by analyzing the controllable potential of the wind-storage combined system and describing the calculation method of the total output power and power allocation principle of the wind-storage combined system based on fuzzy control theory, a wind-storage combined frequency regulation control strategy is formulated to improve the frequency regulation capability and stability, so that the wind turbine can provide active standby support, thereby ensuring stable operation of the system.

[0085] Figure 2 A flow chart of another frequency regulation control method for a wind-storage combined system provided by an embodiment of the present invention is shown in FIG. Figure 2 As shown, the method includes:

[0086] Step 201: Obtain the wind speed of the wind turbine.

[0087] In the embodiment of the present invention, each step is executed by a frequency regulation control device of a wind-storage combined system.

[0088] In the embodiment of the present invention, the wind speed of the wind turbine generator set may be measured by a wind speed measurement tool.

[0089] Step 202 , according to the pre-divided wind speed intervals and the wind speed of the wind turbine generator set, determine whether the wind turbine generator set meets the load reduction operation conditions. If so, execute step 203 ; if not, execute step 204 .

[0090] In an embodiment of the present invention, the wind speed intervals are pre-divided according to actual needs. As an optional scheme, the wind speed interval with a wind speed less than or equal to 6 meters per second (m / s) is divided into wind speed zone 1; the wind speed interval with a wind speed of 6 to 10 m / s is divided into wind speed zone 2; the wind speed interval with a wind speed of 10 to 12 m / s is divided into wind speed zone 3; the wind speed interval with a wind speed greater than or equal to 12 m / s is divided into wind speed zone 4.

[0091] Among them, wind speed zone 1 is a low wind speed zone. In this range, the output power of the DFIG unit is low and the rotor speed is close to the critical value. Therefore, the DFIG unit does not have the frequency regulation capability. This type of unit is not used as a load-reducing operation unit during preventive control. The controllable potential of the wind-storage combined system depends only on the energy storage system.

[0092] The wind speed in wind speed zone 2 is relatively low. In this range, the DFIG unit can operate at reduced load to reserve sufficient spare capacity, and can participate in system frequency regulation through rotor inertia control.

[0093] The DFIG units in wind speed zone 3 can reserve sufficient spare capacity by operating at reduced load. When the wind speed is high, the wind turbine rotor speed is close to the upper limit, and variable pitch control is considered to control the output power. The technical characteristics can be simulated by droop control. Therefore, in this wind speed zone, droop control is additionally considered in the additional frequency control.

[0094] Wind speed zone 4 is a high wind speed zone. At this time, the output of the DFIG unit is maintained near the rated power only through variable pitch control. This type of unit is not used as a load-reducing unit during preventive control. At this time, the controllable potential of the wind-storage combined system depends only on the energy storage system.

[0095] Specifically, if the wind speed of the wind turbine generator belongs to wind speed zone 2 or wind speed zone 3, it indicates that the load reduction operation conditions are met, and step 203 is continued; if the wind speed of the wind turbine generator belongs to wind speed zone 1 or wind speed zone 4, it indicates that the load reduction operation conditions are not met, and step 204 is continued.

[0096] In the embodiment of the present invention, the DFIG unit will be given priority as a load-reducing unit in preventive control only in the appropriate wind speed environment, that is, in wind speed zone 2 and wind speed zone 3, and then participate in frequency regulation after the disturbance. This is also to ensure that the potential of wind power frequency regulation is fully exploited while considering the safety of wind turbine operation. In wind speed zones 1 and 4, traditional wind turbines cannot respond to the system frequency regulation requirements, but the wind-storage combined system can achieve full coverage of the wind speed area, continuously participate in frequency regulation in different wind speed zones with a large span, and provide reliable and stable power support for the system.

[0097] Step 203: Perform load reduction operation on the wind turbine generator set according to the load reduction operation strategy.

[0098] In the embodiment of the present invention, different wind speed intervals correspond to different load reduction operation strategies. The specific load reduction operation strategy can be set according to actual needs, and the embodiment of the present invention does not limit this. As an optional solution, the load reduction operation strategy corresponding to wind speed zone 2 includes participating in system frequency regulation through rotor inertia control; the load reduction operation strategy corresponding to wind speed zone 3 includes using variable pitch to control output power, and the technical characteristics can be simulated by droop control. In this wind speed zone, droop control is additionally considered in additional frequency control.

[0099] Specifically, the load reduction operation strategy corresponding to the wind speed interval in which the wind speed of the wind turbine generator set is located is queried, and the queried load reduction operation strategy is executed.

[0100] In the embodiment of the present invention, according to the controllable potential analysis, a reasonable wind turbine load reduction plan can be formulated according to potential risks before the disturbance, and then the wind turbine and the energy storage system can be frequency-controlled after the disturbance.

[0101] Step 204: Obtain the initial state of charge, rated capacity and rated power of the energy storage system.

[0102] In the embodiment of the present invention, the initial state of charge is the energy storage state of charge at the initial moment; the rated capacity and the rated power both depend on the properties of the energy storage system itself.

[0103] Step 205: Generate a current state of charge according to the initial state of charge, the rated capacity and the rated power.

[0104] In the embodiment of the present invention, discharge is taken as an example for specific description.

[0105] Specifically, through The initial state of charge, rated capacity and rated power are calculated to generate the current state of charge. Among them, SOC(t) is the current state of charge at time t, SOC0 is the initial state of charge, P BESS is the rated power, E BESS is the rated capacity.

[0106] Step 206: According to the current state of charge, determine whether the energy storage system meets the joint frequency regulation conditions. If so, execute step 207; if not, the process ends.

[0107] In the embodiment of the present invention, in order to effectively manage and utilize energy storage resources, the SOC of the energy storage system is usually divided into several intervals, so as to more effectively manage energy flow, balance system load, and improve the overall efficiency and economic benefits of the long-term operation of the wind and storage combined system. The zoning of the state of charge needs to be combined with the requirements of performance, life and grid frequency regulation.

[0108] In an embodiment of the present invention, the SOC interval is pre-divided according to actual needs. As an optional scheme, the interval where the SOC is less than or equal to 0.1 is divided into a low power area; the interval where the SOC is between 0.1 and 0.9 is divided into a reasonable power area; and the interval where the SOC is greater than or equal to 0.9 is divided into a high power area.

[0109] Among them, the energy storage system in the low power area is too low to avoid deep discharge, which will cause great damage to the energy storage unit and shorten its service life. Therefore, the energy storage system is only charged but not discharged.

[0110] The reasonable power range is the ideal range for the operation of energy storage units, which can avoid deep discharge while leaving enough space for charging. In this range, the energy storage unit can charge and discharge more flexibly to cope with the fluctuation of wind energy and changes in grid demand.

[0111] In the high power area, because a long period of high SOC state will also affect the health status and service life of the energy storage unit, in order to avoid overcharging, the energy storage system only discharges but does not charge in the high SOC range.

[0112] Specifically, if the current state of charge is in a reasonable power range, it indicates that the energy storage system meets the joint frequency modulation conditions, and step 207 is continued; if the current state of charge is in a low power range or a high power range, it indicates that the energy storage system does not meet the joint frequency modulation conditions and cannot participate in the joint frequency modulation, and the process ends.

[0113] Step 207: Obtain the frequency offset and frequency change rate of the wind-storage combined system after a disturbance occurs.

[0114] In the embodiment of the present invention, according to the controllable potential analysis, a reasonable wind turbine load reduction plan can be formulated according to potential risks before the disturbance, and then the wind turbine and the energy storage system can be frequency-controlled after the disturbance.

[0115] In the embodiment of the present invention, after a disturbance occurs, the frequency offset Δf and the frequency change rate df / dt of the wind-storage combined system are monitored and counted.

[0116] Step 208: Through the preset first fuzzy logic controller (FCL 1), according to the first membership function and the first fuzzy logic rule table, fuzzy calculation is performed according to the frequency offset and the frequency change rate to generate the total active power increment of the wind-storage combined system.

[0117] In the embodiment of the present invention, FCL 1 describes the severity of the frequency offset and the urgency of the frequency fluctuation rate, and outputs the total active power increment of the wind-storage combined system under controllable potential according to the frequency safety requirements.

[0118] For FCL 1, the inputs are frequency offset and frequency change rate, and the dynamic characteristics of the frequency response are characterized according to the description of fuzzy linguistic variables. Among them, the frequency offset Δf is described as: very small (VS), small (MS), small (S), medium (M), large (L), large (ML), very large (VL), and the range is from -1Hz to 1Hz. The frequency change rate df / dt is described as negative high (NL), negative medium (NM), negative low (NS), zero (Z), positive low (PS), positive medium (PM), and positive high (PL), and the range is from -0.6Hz / s to 0.6Hz / s.

[0119] It is worth noting that the ranges of the above frequency safety indicators may be further modified with reference to system capacity and safety requirements, and the embodiments of the present invention do not limit this.

[0120] As the output of FCL1, the fuzzy linguistic variable of the total active power increment of the wind-storage combined system is set to: very small (VS), small (MS), small (S), medium (M), large (L), large (MB), very large (VB). The maximum frequency regulation capacity of 0 to 0.4pu given is based on the rated power of the wind-storage combined system as a reference value.

[0121] Figure 3 A curve diagram of a frequency offset membership function provided by an embodiment of the present invention is shown in FIG. Figure 3 As shown, the horizontal axis is the frequency offset, with an interval of 0.2 and a range of -1 to 0; the vertical axis is the membership degree, with an interval of 0.2 and a range of 0 to 1. Figure 3 The membership curves of VL, ML, L, M, S, MS, and VS are shown respectively.

[0122] Figure 4 A curve diagram of a frequency change rate membership function provided by an embodiment of the present invention is shown in FIG. Figure 4 As shown, the horizontal axis is the frequency change rate, with an interval of 0.2 and a range of -0.6 to 0.4; the vertical axis is the membership degree, with an interval of 0.2 and a range of 0 to 1. Figure 4 The membership curves of NL, NM, NS, Z, PS, PM, and PL are shown respectively.

[0123] Figure 5 A curve diagram of a total active power increment membership function provided by an embodiment of the present invention is shown in FIG. Figure 5 As shown, the horizontal axis is the output power, with an interval of 0.05 and a range of 0 to 0.4; the vertical axis is the membership degree, with an interval of 0.2 and a range of 0 to 1. Figure 5 The membership curves of VS, MS, S, M, B, MB, and VB are shown respectively.

[0124] In the embodiment of the present invention, the first fuzzy logic rule table is shown in Table 1:

[0125] Table 1

[0126]

[0127] Specifically, the frequency offset and the frequency change rate are input into FCL1, and fuzzy calculation is performed through the first membership function and the first fuzzy logic rule table to output the total active power increment of the wind-storage combined system.

[0128] It is worth noting that the 0.4pu given in the embodiment of the present invention is only a reference value and needs to be replaced according to the estimation of real-time controllable potential. The controllable potential represents the maximum additional power that can be generated by the current wind-storage combined system. The initial controllable potential is mainly determined by the active reserve optimization in the preventive control stage. In the coordinated control stage, it is mainly affected by the real-time operating status of the unit's energy storage system. Therefore, the controllable potential analysis runs through the entire frequency regulation process and is the basis for formulating the wind-storage combined frequency regulation control strategy.

[0129] Step 209: Generate the additional power capability of the wind turbine generator system according to the speed parameter and the power parameter.

[0130] In the embodiment of the present invention, since the energy storage system is a supplement to the frequency regulation of the wind turbine generator set, the power capacity that the current wind turbine generator set can generate is first considered. The frequency regulation capacity of the wind turbine generator set is determined by the speed factor and the power factor.

[0131] In the embodiment of the present invention, step 209 specifically includes:

[0132] Step 2091: Generate speed frequency modulation capability according to the speed parameter.

[0133] In the embodiment of the present invention, the speed parameter includes but is not limited to the actual value of the rotor speed, the maximum speed at the current wind speed, and the minimum speed at the current wind speed.

[0134] In the embodiment of the present invention, the speed of the wind turbine directly affects its output power. However, when the speed approaches its limit value, the control system may not be able to further adjust the output of the wind turbine to ensure the safe operation of the unit. Moreover, the influence of different control modes on the speed is also significantly different. For example, the method of releasing kinetic energy often reduces the rotor speed, while the speed needs to be increased to obtain greater power output when the wind speed increases. Therefore, considering the kinetic energy change and the speed range limitation, from the perspective of speed safety, the coefficient k is defined. m Quantify the real-time frequency regulation capability of the unit:

[0135]

[0136] Among them, k m is the speed frequency regulation capability, ω r_max is the maximum speed under the current wind speed, ω r is the actual value of the rotor speed, ω r_min It is the minimum rotation speed under the current wind speed.

[0137] Step 2092: Generate power frequency modulation capability according to the power parameter.

[0138] In the embodiment of the present invention, the power parameters include but are not limited to the actual value of the active power of the wind turbine generator set, the maximum value of the active power of the wind turbine generator set at the current wind speed, and the initial value of the active power of the wind turbine generator set after load reduction operation.

[0139] In the embodiment of the present invention, in order to describe the real-time controllable potential of the unit in the real-time frequency regulation process and prevent the occurrence of insufficient controllable capacity, the coefficient k is defined from the perspective of unit power safety based on the proportion of the remaining power that can be generated by the current unit. e Quantify the real-time frequency regulation capability of the unit:

[0140]

[0141] Among them, k e is the power frequency modulation capability, P e_max is the maximum active power of the wind turbine at the current wind speed, P e is the actual value of active power of wind turbine, P e_0 It is the initial value of the active power of the wind turbine after load reduction operation.

[0142] Step 2093: compare the speed frequency regulation capability and the power frequency regulation capability to determine the additional power capability of the wind turbine generator set.

[0143] In the embodiment of the present invention, since the speed of the unit and the electromagnetic power are reversely coupled during the frequency modulation process, the smallest of the two can represent the power increase capability K of the current wind turbine unit. w :

[0144] K w =min(k m ,k e )

[0145] Step 210: Generate the additional power capability of the energy storage system according to the current state of charge and frequency offset.

[0146] In the embodiment of the present invention, the current additional power capacity of the energy storage system is considered, which is only related to the current state of charge SOC. Therefore, the current additional power capacity K of the energy storage system is s :

[0147]

[0148] Among them, K s is the additional power capacity of the wind turbine, Δf is the frequency offset, SOC is the current state of charge, SOC max The maximum state of charge, SOC min is the minimum state of charge.

[0149] Step 211, the preset second fuzzy logic controller (FLC 2) performs fuzzy calculation on the additional power capacity of the wind turbine and the additional power capacity of the energy storage system according to the second membership function and the second fuzzy logic rule table, and generates a frequency regulation participation coefficient of the wind turbine.

[0150] In the embodiment of the present invention, FCL2 monitors the operating conditions of the wind turbine and the energy storage system in real time, determines the allocation of the total active power increment between the wind turbine and the energy storage system based on the comparison of the remaining incremental power capacity, and outputs the wind turbine frequency regulation participation coefficient.

[0151] For FCL2, the current remaining controllable capacity is evaluated during the process of wind-storage combined system participating in system frequency regulation, and the allocation task of active power increment is further realized based on the output results of FCL1. Therefore, what needs to be considered is the real-time power increase capacity of wind turbines and energy storage systems, which depends on the controllable potential analysis under the initial situation and the output situation during the real-time frequency regulation process.

[0152] Wind turbine can increase power capacity K w And the energy storage system can increase the power capacity K s They are used as the input of FCL2 respectively, and the wind turbine frequency modulation participation coefficient β is output after fuzzy relationship. w And the energy storage system can increase the power capacity K s They are described as: very small (VS), small (MS), small (S), medium (M), large (B), large (MB), very large (VB), and the range is from 0 to 1. The frequency regulation participation coefficient β of wind turbines is described as: very small (VS), small (S), medium (M), large (B), very large (VB), and the range is from 0 to 1.

[0153] Figure 6 A curve diagram of a membership function of the wind turbine generator system's additional power capability provided by an embodiment of the present invention is shown in FIG. Figure 6 As shown, the horizontal axis is the additional power capacity of the wind turbine, with an interval of 0.2 and a range of 0 to 1; the vertical axis is the degree of membership, with an interval of 0.2 and a range of 0 to 1. Figure 6 The membership curves of VS, S, MS, MB, B, and VB are shown respectively.

[0154] Figure 7 A schematic diagram of a curve of a membership function of the incremental power capability of an energy storage system provided by an embodiment of the present invention, such as Figure 7 As shown, the horizontal axis is the power capacity of the energy storage system, with an interval of 0.1 and a range of 0.1 to 0.9; the vertical axis is the degree of membership, with an interval of 0.2 and a range of 0 to 1. Figure 7The membership curves of VS, S, MS, MB, B, and VB are shown respectively.

[0155] Figure 8 A curve diagram of a membership function of a wind turbine frequency regulation participation coefficient provided by an embodiment of the present invention is shown in FIG. Figure 8 As shown, the horizontal axis is the wind turbine frequency regulation participation coefficient, with an interval of 0.2 and a range of 0 to 1; the vertical axis is the membership degree, with an interval of 0.2 and a range of 0 to 1. Figure 8 The membership curves of VS, S, M, B, and VB are shown respectively.

[0156] In the embodiment of the present invention, the second fuzzy logic rule table is shown in Table 2:

[0157] Table 2

[0158]

[0159] Specifically, the additional power capacity of the wind turbine and the additional power capacity of the energy storage system are input into FCL2, and fuzzy calculation is performed through the second membership function and the second fuzzy logic rule table to output the frequency regulation participation coefficient of the wind turbine.

[0160] The fuzzy logic rules are mainly based on the following principles:

[0161] (1) In most cases, the spare capacity of wind turbines is used for frequency control first, so that wind turbines bear a larger power share, that is, the wind turbine frequency regulation participation coefficient β is larger and should be greater than 0.5.

[0162] (2) When only wind turbines can generate additional power K w When it is small, for the sake of wind turbine operation safety, priority should be given to ensuring the stable operation of wind turbines, allowing the energy storage system to bear a larger power share, that is, the wind turbine frequency regulation participation coefficient β is small and should be less than 0.

[0163] (3) When the wind turbine can increase its power capacity K w The power capacity that can be increased with the energy storage system is K s When both are small, considering that the energy storage system may not be able to provide timely power support if the wind turbine exits unexpectedly, resulting in a secondary drop in frequency, the wind turbine frequency regulation participation coefficient β is very small at this time and should be greater than 0 and less than 0.5.

[0164] Step 212: Perform frequency regulation control on the wind-storage combined system according to the frequency regulation participation coefficient of the wind turbine generator set and the total active power increment.

[0165] In the embodiment of the present invention, step 212 specifically includes:

[0166] Step 2121: Generate the wind turbine active power increment according to the wind turbine frequency regulation participation coefficient and the total active power increment, and distribute the wind turbine active power increment to the wind turbine.

[0167] Specifically, the frequency regulation participation coefficient of the wind turbine generator set is multiplied by the total active power increment to generate the active power increment of the wind turbine generator set, and the active power increment of the wind turbine generator set is distributed to the wind turbine generator set.

[0168] Step 2122: Determine the frequency regulation participation coefficient of the energy storage system according to the frequency regulation participation coefficient of the wind turbine generator set.

[0169] Specifically, the result of 1-β is determined as the frequency regulation participation coefficient of the energy storage system, where β is the frequency regulation participation coefficient of the wind turbine.

[0170] Step 2123: Generate the active power increment of the energy storage system according to the frequency regulation participation coefficient of the energy storage system and the total active power increment, and distribute the active power increment of the energy storage system to the energy storage system.

[0171] Specifically, the frequency regulation participation coefficient of the energy storage system is multiplied by the total active power increment to generate the active power increment of the energy storage system, and the active power increment of the energy storage system is distributed to the energy storage system.

[0172] It is worth noting that the active power increment of wind turbines and the active power increment of energy storage systems need to be compared with the current controllable potential. If the requirements cannot be met, the fuzzy linguistic variable ratings will be gradually lowered until the requirements are met.

[0173] In order to verify the effectiveness of the proposed wind-storage system joint frequency regulation control strategy, the embodiment of the present invention will use example systems with different capacities for simulation verification, namely a four-machine two-area system and an IEEE39-node system. Both systems use normal wind speed (8m / s) and extreme wind speed (4m / s) and sufficient SOC examples for analysis.

[0174] Fig. 9 The frequency variation diagram of the four-machine two-zone system under normal wind speed is shown in Figure 2. Fig. 9 As shown, the horizontal axis is time (s), with an interval of 5 and a range of 0 to 30; the vertical axis is frequency (Hz), with an interval of 0.1 and a range of 49.4 to 50. Fig. 9 The red curve is the frequency change curve of wind power and storage combined frequency regulation, the blue curve is the frequency change curve of additional wind power frequency regulation, and the black curve is the frequency change curve of only traditional unit frequency regulation. Comparison of multiple frequency change curves shows that wind power and storage combined frequency regulation achieves frequency stabilization in the shortest time.

[0175] Fig.10 The following is a schematic diagram of the additional power change of the four-machine two-zone system under normal wind speed. Fig.10As shown, the horizontal axis is time (s), with an interval of 5 and a range of 0 to 30; the vertical axis is the additional power (pu), with an interval of 0.05 and a range of 0 to 0.2. Fig.10 The red curve in the middle is the power increase change curve of the energy storage system, and the blue curve is the power increase change curve of the wind turbine.

[0176] Fig.11 The frequency variation diagram of the four-machine two-zone system under extreme wind speed is shown in Figure 2. Fig.11 As shown, the horizontal axis is time (s), with an interval of 5 and a range of 0 to 30; the vertical axis is frequency (Hz), with an interval of 0.1 and a range of 49.4 to 50. Fig.11 The red curve in the middle is the frequency change curve of wind-storage combined frequency regulation, and the blue curve is the frequency change curve of only traditional unit frequency regulation. Comparison of multiple frequency change curves shows that wind-storage combined frequency regulation achieves frequency stabilization in the shortest time.

[0177] Fig.12 The following is a schematic diagram of the power increase change of the four-machine two-zone system under extreme wind speed. Fig.12 As shown, the horizontal axis is time (s), with an interval of 5 and a range of 0 to 30; the vertical axis is the additional power (pu), with an interval of 0.05 and a range of 0 to 0.1. Fig.12 The middle curve is the power increase curve of the energy storage system.

[0178] Fig.13 The frequency variation diagram of the IEEE39 node system under normal wind speed is shown in Figure 1. Fig.13 As shown, the horizontal axis is time (s), with an interval of 20 and a range of 0 to 100; the vertical axis is frequency (Hz), with an interval of 0.05 and a range of 49.85 to 50. Fig.13 The red curve in the middle is the frequency change curve of wind-storage combined frequency regulation, and the blue curve is the frequency change curve of only traditional unit frequency regulation. Comparison of multiple frequency change curves shows that wind-storage combined frequency regulation achieves frequency stabilization in the shortest time.

[0179] Fig.14 The following is a schematic diagram of the additional power change of the IEEE39 node system under normal wind speed. Fig.14 As shown, the horizontal axis is time (s), with an interval of 10 and a range of 0 to 50; the vertical axis is the additional power (pu), with an interval of 0.05 and a range of 0 to 0.1. Fig.14 The red curve in the middle is the curve of the wind turbine's increased power generation, and the blue curve is the curve of the energy storage system's increased power generation.

[0180] Fig.15 The frequency variation diagram of the IEEE 39-node system under extreme wind speed is shown in Figure 2. Fig.15As shown, the horizontal axis is time (s), with an interval of 20 and a range of 0 to 100; the vertical axis is frequency (Hz), with an interval of 0.05 and a range of 49.85 to 50. Fig.15 The red curve in the middle is the frequency change curve of wind-storage combined frequency regulation, and the blue curve is the frequency change curve of only traditional unit frequency regulation. Comparison of multiple frequency change curves shows that wind-storage combined frequency regulation achieves frequency stabilization in the shortest time.

[0181] Fig.16 This is a schematic diagram of the additional power change of the IEEE39 node system under the positive extreme wind speed. Fig.16 As shown, the horizontal axis is time (s), with an interval of 10 and a range of 0 to 50; the vertical axis is the additional power (pu), with an interval of 0.01 and a range of 0 to 0.05. Fig.16 The middle curve is the power increase curve of the energy storage system.

[0182] In summary, the comparison of frequency safety indicators under different operating modes at normal wind speed is shown in Table 3:

[0183] Table 3

[0184]

[0185]

[0186] The comparison of frequency safety indicators under different operating modes at extreme wind speeds is shown in Table 4:

[0187] Table 4

[0188] FM Mode Initial frequency change rate Frequency minimum Frequency steady state value Wind power without frequency regulation 0.536Hz / s 49.43Hz 49.88Hz Wind and energy storage combined frequency regulation 0.358Hz / s 49.61Hz 49.89Hz

[0189] The comparison of frequency safety indicators under different operating modes is shown in Table 5:

[0190] Table 5

[0191]

[0192] It is worth noting that the acquisition, storage, use, and processing of data in the technical solution of this application are in compliance with the relevant provisions of laws and regulations. The user information in the embodiments of this application is obtained through legal and compliant channels, and the acquisition, storage, use, and processing of user information are authorized and agreed by the customer.

[0193] It is worth noting that the information collected in this application is information and data authorized by the user or fully authorized by all parties, and the collection, storage, use, processing, transmission, provision, disclosure and application of relevant data comply with the relevant laws, regulations and standards of relevant countries and regions, take necessary confidentiality measures, do not violate public order and good customs, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0194] It is worth noting that the technical solution provided in this application provides users with corresponding operation entrances for them to choose to agree or reject the automated decision-making results; if the user chooses to reject, the expert decision-making process will be entered.

[0195] In the technical solution of the frequency regulation control method of the wind-storage combined system provided by the embodiment of the present invention, the frequency offset and the frequency change rate after the disturbance occurs in the wind-storage combined system are obtained, and the wind-storage combined system includes a wind turbine and an energy storage system; through a preset first fuzzy logic controller, according to the first membership function and the first fuzzy logic rule table, fuzzy calculation is performed according to the frequency offset and the frequency change rate to generate the total active power increment of the wind-storage combined system; through a preset second fuzzy logic controller, according to the second membership function and the second fuzzy logic rule table, fuzzy calculation is performed according to the wind turbine operating parameters and the current charge state of the energy storage system to generate the wind turbine frequency regulation participation coefficient; according to the wind turbine frequency regulation participation coefficient and the total active power increment, the wind-storage combined system is frequency regulated and controlled, and by analyzing the controllable potential of the wind-storage combined system and describing the calculation method of the total output power and power allocation principle of the wind-storage combined system based on fuzzy control theory, a wind-storage combined frequency regulation control strategy is formulated to improve the frequency regulation capability and stability, so that the wind turbine can provide active standby support, thereby ensuring stable operation of the system.

[0196] Fig.17 Schematic diagram of a frequency regulation control device for a wind-storage combined system provided by an embodiment of the present invention, the device is used to execute the frequency regulation control method for the wind-storage combined system, such as Fig.17 As shown, the device includes: a frequency parameter acquisition unit 11, a first fuzzy calculation unit 12, a second fuzzy calculation unit 13 and a frequency modulation control unit 14.

[0197] The frequency parameter acquisition unit 11 is used to acquire the frequency offset and frequency change rate of the wind-storage combined system after a disturbance occurs. The wind-storage combined system includes a wind turbine and an energy storage system.

[0198] The first fuzzy calculation unit 12 is used to generate a total active power increment of the wind-storage combined system by performing fuzzy calculation according to the frequency offset and the frequency change rate through a preset first fuzzy logic controller, according to the first membership function and the first fuzzy logic rule table.

[0199] The second fuzzy calculation unit 13 is used to generate a frequency regulation participation coefficient of the wind turbine set by performing fuzzy calculation according to the second membership function and the second fuzzy logic rule table based on the wind turbine set operating parameters and the current charge state of the energy storage system through a preset second fuzzy logic controller.

[0200] The frequency regulation control unit 14 is used to perform frequency regulation control on the wind-storage combined system according to the frequency regulation participation coefficient of the wind turbine generator set and the total active power increment.

[0201] In the embodiment of the present invention, the device further includes: a wind speed acquisition unit 15 , a load reduction judgment unit 16 and a load reduction operation unit 17 .

[0202] The wind speed acquisition unit 15 is used to acquire the wind speed of the wind turbine.

[0203] The load shedding judgment unit 16 is used to judge whether the wind turbine generator set meets the load shedding operation condition according to the wind speed of the wind turbine generator set in accordance with the pre-divided wind speed intervals.

[0204] The load reduction operation unit 17 is used to perform load reduction operation on the wind turbine generator set according to the load reduction operation strategy.

[0205] In the embodiment of the present invention, the device further includes: an energy storage parameter acquisition unit 18 , a state of charge generation unit 19 and a frequency modulation determination unit 20 .

[0206] The energy storage parameter acquisition unit 18 is used to obtain the initial state of charge, rated capacity and rated power of the energy storage system;

[0207] The state of charge generating unit 19 is used to generate the current state of charge according to the initial state of charge, the rated capacity and the rated power;

[0208] The frequency regulation judgment unit 20 is used to judge whether the energy storage system meets the joint frequency regulation conditions according to the current charge state; if so, the trigger frequency parameter acquisition unit 11 continues to execute the steps of obtaining the frequency offset and frequency change rate after the disturbance occurs in the wind-storage combined system, and the wind-storage combined system includes a wind turbine and an energy storage system.

[0209] In an embodiment of the present invention, the operating parameters of the wind turbine include speed parameters and power parameters; the second fuzzy calculation unit 13 is specifically used to generate the increaseable power capacity of the wind turbine according to the speed parameters and the power parameters; generate the increaseable power capacity of the energy storage system according to the current state of charge and the frequency offset; the preset second fuzzy logic controller performs fuzzy calculations on the increaseable power capacity of the wind turbine and the increaseable power capacity of the energy storage system according to the second membership function and the second fuzzy logic rule table, and generates the frequency regulation participation coefficient of the wind turbine.

[0210] In the embodiment of the present invention, the second fuzzy calculation unit 13 is specifically used to generate a speed frequency regulation capability according to a speed parameter; generate a power frequency regulation capability according to a power parameter; compare the speed frequency regulation capability and the power frequency regulation capability to determine the additional power capability of the wind turbine set.

[0211] In the embodiment of the present invention, the frequency regulation control unit 14 is specifically used to generate an active power increment of the wind turbine group according to the frequency regulation participation coefficient of the wind turbine group and the total active power increment, and distribute the active power increment of the wind turbine group to the wind turbine group; determine the frequency regulation participation coefficient of the energy storage system according to the frequency regulation participation coefficient of the wind turbine group; generate the active power increment of the energy storage system according to the frequency regulation participation coefficient of the energy storage system and the total active power increment, and distribute the active power increment of the energy storage system to the energy storage system.

[0212] In the scheme of the embodiment of the present invention, the frequency offset and frequency change rate of the wind-storage combined system after a disturbance occurs are obtained, and the wind-storage combined system includes a wind turbine and an energy storage system; through a preset first fuzzy logic controller, according to a first membership function and a first fuzzy logic rule table, fuzzy calculation is performed according to the frequency offset and the frequency change rate to generate a total active power increment of the wind-storage combined system; through a preset second fuzzy logic controller, according to a second membership function and a second fuzzy logic rule table, fuzzy calculation is performed according to the wind turbine operating parameters and the current charge state of the energy storage system to generate a wind turbine frequency regulation participation coefficient; according to the wind turbine frequency regulation participation coefficient and the total active power increment, the wind-storage combined system is frequency-controlled, and by analyzing the controllable potential of the wind-storage combined system and describing the calculation method of the total output power and power allocation principle of the wind-storage combined system based on fuzzy control theory, a wind-storage combined frequency regulation control strategy is formulated to improve the frequency regulation capability and stability, so that the wind turbine can provide active standby support, thereby ensuring stable operation of the system.

[0213] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer device, and specifically, the computer device may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0214] An embodiment of the present invention provides a computer device, including a memory and a processor, the memory is used to store information including program instructions, the processor is used to control the execution of the program instructions, and when the program instructions are loaded and executed by the processor, the steps of the embodiment of the above-mentioned wind-storage combined system frequency regulation control method are implemented. For a specific description, please refer to the embodiment of the above-mentioned wind-storage combined system frequency regulation control method.

[0215] Reference below Fig.18 , which shows a schematic diagram of the structure of a computer device 600 suitable for implementing an embodiment of the present application.

[0216] like Fig.18 As shown, the computer device 600 includes a central processing unit (CPU) 601, which can perform various appropriate operations and processes according to a program stored in a read-only memory (ROM) 602 or a program loaded from a storage part 608 into a random access memory (RAM) 603. In the RAM 603, various programs and data required for the operation of the computer device 600 are also stored. The CPU 601, the ROM 602, and the RAM 603 are connected to each other via a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.

[0217] The following components are connected to the I / O interface 605: an input section 606 including a keyboard, a mouse, etc.; an output section 607 including a cathode ray tube (CRT), a liquid crystal feedback device (LCD), etc., and a speaker, etc.; a storage section 608 including a hard disk, etc.; and a communication section 609 including a network interface card such as a LAN card, a modem, etc. The communication section 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to the I / O interface 605 as needed. A removable medium 611, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 610 as needed, so that a computer program read therefrom is installed as needed as the storage section 608.

[0218] In particular, according to an embodiment of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program tangibly contained on a machine-readable medium, and the computer program includes program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through the communication part 609, and / or installed from the removable medium 611.

[0219] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0220] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0221] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, 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 device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0222] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0223] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0224] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0225] The acquisition, storage, use, and processing of data in the technical solution of this application comply with the relevant provisions of national laws and regulations.

[0226] It should be noted that in the embodiments of the present application, certain software, components, models and other existing solutions in the industry may be mentioned, and they should be regarded as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0227] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0228] The present application may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0229] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0230] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A frequency modulation control method for a wind-storage combined system, characterized in that: The method comprises: Obtaining a frequency offset and a frequency change rate after a disturbance occurs in a wind-storage combined system, wherein the wind-storage combined system includes a wind turbine and an energy storage system; By using a preset first fuzzy logic controller, according to a first membership function and a first fuzzy logic rule table, fuzzy calculation is performed according to the frequency offset and the frequency change rate to generate a total active power increment of the wind-storage combined system; By using a preset second fuzzy logic controller, according to a second membership function and a second fuzzy logic rule table, fuzzy calculation is performed according to the wind turbine operating parameters and the current charge state of the energy storage system to generate a wind turbine frequency modulation participation coefficient; The frequency regulation of the wind-storage combined system is controlled according to the frequency regulation participation coefficient of the wind turbine generator set and the total active power increment.

2. The frequency modulation control method of the wind-storage combined system according to claim 1 is characterized in that: The method further comprises: Obtaining the wind speed of the wind turbine generator set; According to the pre-divided wind speed interval, judging whether the wind turbine generator set meets the load reduction operation condition according to the wind speed of the wind turbine generator set; If so, the wind turbine generator set is operated with reduced load according to the reduced load operation strategy.

3. The frequency modulation control method of the wind-storage combined system according to claim 1 is characterized in that: The method further comprises: Obtaining an initial state of charge, rated capacity and rated power of the energy storage system; generating a current state of charge according to the initial state of charge, the rated capacity and the rated power; According to the current state of charge, determining whether the energy storage system meets the joint frequency regulation conditions; If so, continue to execute the step of obtaining the frequency offset and frequency change rate of the wind-storage combined system after the disturbance occurs, and the wind-storage combined system includes a wind turbine and an energy storage system.

4. The frequency modulation control method of the wind-storage combined system according to claim 1 is characterized in that: The wind turbine operating parameters include speed parameters and power parameters; The method of performing fuzzy calculation according to the second membership function and the second fuzzy logic rule table based on the wind turbine operating parameters and the current state of charge of the energy storage system to generate the wind turbine frequency modulation participation coefficient includes: Generating the additional power capacity of the wind turbine generator set according to the speed parameter and the power parameter; Generating an additional power capacity of the energy storage system according to the current state of charge and the frequency offset; The preset second fuzzy logic controller performs fuzzy calculation on the additional power capacity of the wind turbine set and the additional power capacity of the energy storage system according to the second membership function and the second fuzzy logic rule table, and generates the frequency regulation participation coefficient of the wind turbine set.

5. The frequency modulation control method of the wind-storage combined system according to claim 4 is characterized in that: Generating the additional power capability of the wind turbine generator set according to the speed parameter and the power parameter includes: Generate a speed frequency modulation capability according to the speed parameter; generating a power frequency modulation capability according to the power parameter; The speed frequency regulation capability and the power frequency regulation capability are compared to determine the additional power capability of the wind turbine generator set.

6. The frequency modulation control method of the wind-storage combined system according to claim 1 is characterized in that: The step of performing frequency regulation control on the wind-storage combined system according to the frequency regulation participation coefficient of the wind turbine generator set and the total active power increment comprises: Generate an active power increment of the wind turbine generator set according to the frequency regulation participation coefficient of the wind turbine generator set and the total active power increment, and distribute the active power increment of the wind turbine generator set to the wind turbine generator set; Determining the frequency regulation participation coefficient of the energy storage system according to the frequency regulation participation coefficient of the wind turbine generator set; According to the frequency regulation participation coefficient of the energy storage system and the total active power increment, the active power increment of the energy storage system is generated, and the active power increment of the energy storage system is distributed to the energy storage system.

7. A frequency modulation control device for a wind-storage combined system, characterized in that: The device comprises: A frequency parameter acquisition unit, used to acquire a frequency offset and a frequency change rate after a disturbance occurs in a wind-storage combined system, wherein the wind-storage combined system includes a wind turbine and an energy storage system; A first fuzzy calculation unit is used to generate a total active power increment of the wind-storage combined system by performing fuzzy calculation according to the frequency offset and the frequency change rate through a preset first fuzzy logic controller according to a first membership function and a first fuzzy logic rule table; A second fuzzy calculation unit is used to generate a frequency regulation participation coefficient of the wind turbine set by performing fuzzy calculation according to the second membership function and the second fuzzy logic rule table based on the wind turbine set operating parameters and the current charge state of the energy storage system through a preset second fuzzy logic controller; The frequency regulation control unit is used to perform frequency regulation control on the wind-storage combined system according to the frequency regulation participation coefficient of the wind turbine set and the total active power increment.

8. The frequency regulation control device for the wind-storage combined system according to claim 7 is characterized in that: The device also includes: A wind speed acquisition unit, used to acquire the wind speed of the wind turbine; A load shedding judgment unit, used to judge whether the wind turbine generator set meets the load shedding operation condition according to the wind speed of the wind turbine generator set in accordance with the pre-divided wind speed interval; The load reduction operation unit is used to perform load reduction operation on the wind turbine set according to the load reduction operation strategy.

9. The frequency regulation control device for the wind-storage combined system according to claim 7, characterized in that: The device also includes: An energy storage parameter acquisition unit, used to obtain the initial state of charge, rated capacity and rated power of the energy storage system; a state of charge generating unit, configured to generate a current state of charge according to the initial state of charge, the rated capacity and the rated power; The frequency regulation judgment unit is used to judge whether the energy storage system meets the joint frequency regulation conditions according to the current charge state; if so, the trigger frequency parameter acquisition unit continues to execute the step of obtaining the frequency offset and frequency change rate after the wind-storage combined system is disturbed, and the wind-storage combined system includes a wind turbine and an energy storage system.

10. The frequency regulation control device for the wind-storage combined system according to claim 7, characterized in that: The wind turbine operating parameters include speed parameters and power parameters; The second fuzzy calculation unit is specifically used to generate the additional power capacity of the wind turbine according to the speed parameter and the power parameter; and to generate the additional power capacity of the energy storage system according to the current state of charge and the frequency offset; The preset second fuzzy logic controller performs fuzzy calculation on the additional power capacity of the wind turbine set and the additional power capacity of the energy storage system according to the second membership function and the second fuzzy logic rule table, and generates the frequency regulation participation coefficient of the wind turbine set.

11. The frequency regulation control device for the wind-storage combined system according to claim 10, characterized in that: The second fuzzy calculation unit is specifically used to generate a speed frequency regulation capability according to the speed parameter; generate a power frequency regulation capability according to the power parameter; compare the speed frequency regulation capability and the power frequency regulation capability to determine the additional power capacity of the wind turbine.

12. The frequency regulation control device for the wind-storage combined system according to claim 7, characterized in that: The frequency regulation control unit is specifically used to generate an active power increment of the wind turbine group according to the frequency regulation participation coefficient of the wind turbine group and the total active power increment, and distribute the active power increment of the wind turbine group to the wind turbine group; determine the frequency regulation participation coefficient of the energy storage system according to the frequency regulation participation coefficient of the wind turbine group; generate an active power increment of the energy storage system according to the frequency regulation participation coefficient of the energy storage system and the total active power increment, and distribute the active power increment of the energy storage system to the energy storage system.

13. A computer readable medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the frequency regulation control method of the wind-storage combined system described in any one of claims 1 to 6 is implemented.

14. A computer device comprising a memory and a processor, wherein the memory is used to store information including program instructions, and the processor is used to control the execution of the program instructions, characterized in that: When the program instructions are loaded and executed by the processor, the frequency regulation control method of the wind-storage combined system described in any one of claims 1 to 6 is implemented.

15. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by the processor, the frequency regulation control method of the wind-storage combined system described in any one of claims 1 to 6 is implemented.

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