Method of controlling a wind turbine and wind turbine

Abstract

The present disclosure provides a wind turbine generator control method and a wind turbine generator. The control method comprises: determining a current energy storage level of the energy storage device; in response to the current energy storage level being within a preset working range, controlling the energy storage device to charge or discharge according to the operation requirement of the wind turbine generator; and in response to the current energy storage level being outside the preset working range, controlling the energy storage device to charge or discharge according to the degree of deviation of the current energy storage level from the preset working range. The wind turbine generator control method and the wind turbine generator according to the present disclosure solve the problem of single and inflexible control mode of the energy storage device, and can flexibly control the charging and discharging process of the energy storage device, optimize the energy storage control and realize the collaborative control of the whole machine by taking into account the actual energy storage state of the energy storage device while considering the operation requirement of the wind turbine generator.

Description

Technical Field

[0001] This disclosure relates to the field of wind power generation, and more specifically, to a control method for a wind turbine generator set and a wind turbine generator set. Background Technology

[0002] With the development of wind power technology, equipping individual units with energy storage devices has become a major trend in the industry. For example, taking wind turbine generator sets as an example, the energy storage device can be controlled by an energy storage converter to carry out the charging and discharging process in order to store and release energy.

[0003] In the control schemes of relevant energy storage devices, the energy storage devices are generally connected to the AC grid independently, and the control methods are relatively simple and the control process is not flexible enough. However, in actual unit operation, the state of the energy storage device and the operating state of the unit are changing, and the operating conditions that energy storage control needs to face are more complex. This requires more flexible and detailed control of the energy storage device. Summary of the Invention

[0004] In view of the problem that the control methods for energy storage devices in related technologies are too simple and inflexible, this disclosure provides a control method for wind turbine generator sets and a wind turbine generator set.

[0005] The first aspect of this disclosure provides a control method for a wind turbine generator set, the wind turbine generator set including an energy storage device and an energy storage converter, one end of the energy storage converter being connected to the DC bus of the wind turbine generator set, and the other end of the energy storage converter being connected to the energy storage device, wherein the control method includes: determining the current energy storage level of the energy storage device; in response to the current energy storage level being within a preset operating range, controlling the energy storage device to charge or discharge according to the operating requirements of the wind turbine generator set; and in response to the current energy storage level being outside the preset operating range, controlling the energy storage device to charge or discharge according to the degree to which the current energy storage level deviates from the preset operating range.

[0006] Optionally, controlling the charging or discharging of the energy storage device according to the degree to which the current energy storage level deviates from the preset operating range includes: in response to the current energy storage level being in a first range deviating from the preset operating range, controlling the charging or discharging of the energy storage device according to the operating state of the wind turbine generator; and in response to the current energy storage level being in a second range deviating from the preset operating range, controlling the charging or discharging of the energy storage device according to the energy storage demand of the energy storage device, wherein the degree to which the second range deviates from the preset operating range is greater than the degree to which the first range deviates from the preset operating range.

[0007] Optionally, controlling the charging or discharging of the energy storage device according to the operating state of the wind turbine generator set includes: in response to the wind turbine generator set being in primary frequency regulation state, controlling the charging or discharging of the energy storage device according to the power demand of the primary frequency regulation to provide power support for the primary frequency regulation; in response to the wind turbine generator set not being in primary frequency regulation state, controlling the charging or discharging of the energy storage device according to the energy storage demand of the energy storage device to ensure that the energy storage level of the energy storage device is within the preset operating range.

[0008] Optionally, controlling the charging or discharging of the energy storage device according to its energy storage requirements includes: controlling the charging or discharging of the energy storage device according to the deviation of the current energy storage level from the preset operating range, so that the energy storage level of the energy storage device is within the preset operating range.

[0009] Optionally, the power configuration of the energy storage device is determined based on the power demand for smoothing fluctuations and the power regulation demand, wherein the power demand for smoothing fluctuations is the power demand for smoothing wind power fluctuations, and the power regulation demand is the power demand for the energy storage device to provide power regulation to the power grid.

[0010] Optionally, the preset operating range is determined by: ensuring that a first energy configuration of the energy storage device within the preset operating range meets the energy requirement for providing power regulation support to the grid a preset number of times, wherein the first range includes a first discharge range and a first charging range, and the first discharge range and the first charging range are determined by: ensuring that a second energy configuration of the energy storage device within the first discharge range and a third energy configuration within the first charging range both meet the energy requirement for providing power regulation support to the grid once, thereby determining the first discharge range and the first charging range.

[0011] Optionally, the energy storage device includes a supercapacitor, wherein the first discharge range and the first charging range are determined by: determining an upper limit voltage corresponding to the first discharge range based on the maximum withstand voltage of the supercapacitor; and determining the capacitance of the supercapacitor, the lower limit voltage corresponding to the first discharge range, and the upper limit voltage corresponding to the first charging range based on the upper limit voltage corresponding to the first discharge range, a preset lower limit voltage corresponding to the first charging range, the first energy configuration, the second energy configuration, and the third energy configuration.

[0012] Optionally, the energy storage device includes a rechargeable battery, wherein the first discharge range and the first charging range are determined by: determining an upper limit ratio corresponding to the first discharge range based on the maximum safe capacity of the rechargeable battery; and determining the total capacity of the rechargeable battery, the lower limit ratio corresponding to the first discharge range, and the upper limit ratio corresponding to the first charging range based on the upper limit ratio corresponding to the first discharge range, a preset lower limit ratio corresponding to the first charging range, the second energy configuration, and the third energy configuration.

[0013] Optionally, the control method further includes: determining a first reference power for controlling the generator-side converter of the wind turbine and a second reference power for controlling the grid-side converter of the wind turbine; and controlling the energy storage device to charge or discharge based on the difference between the first reference power and the second reference power and a preset difference range, so as to provide power regulation support for smoothing wind power fluctuations of the wind turbine, wherein the preset difference range represents the power range for smoothing wind power fluctuations.

[0014] Optionally, the second reference power is determined by performing time smoothing processing on the first reference power based on a preset time smoothing constant to obtain the second reference power.

[0015] A second aspect of this disclosure provides a computer device including a processor and a memory: the memory is used to store program code and transmit the program code to the processor; the processor is used to execute a control method for a wind turbine generator according to an embodiment of this disclosure based on instructions in the program code.

[0016] A third aspect of this disclosure provides a wind turbine generator set, the wind turbine generator set including the computer equipment described in embodiments of this disclosure.

[0017] A fourth aspect of this disclosure provides a computer-readable storage medium storing a program or instructions that, when executed by a processor, implement the control method for a wind turbine generator according to embodiments of this disclosure.

[0018] According to the wind turbine generator control method and wind turbine generator disclosed herein, the charging and discharging of the energy storage device can be comprehensively controlled based on the current energy storage level of the energy storage device and the operating requirements of the wind turbine generator. Furthermore, when the energy storage level deviates from the preset operating range, the charging and discharging of the energy storage device can be controlled based on the actual degree of deviation. In this way, while taking into account the operating requirements of the wind turbine generator, the actual energy storage state of the energy storage device can be considered, the relationship between the state of the energy storage device and the operating state of the generator can be balanced, the charging and discharging process of the energy storage device can be flexibly controlled, the energy storage control can be optimized, and the coordinated control of the entire unit can be achieved. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the structure of an integrated wind and energy storage system according to an exemplary embodiment of the present disclosure.

[0020] Figure 2 This is a schematic flowchart illustrating a control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0021] Figure 3 This is a schematic diagram illustrating the range of energy storage levels of an energy storage device in a control method for a wind turbine generator according to an exemplary embodiment of the present disclosure.

[0022] Figure 4 This is a schematic flowchart illustrating the cooperative control steps in a control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0023] Figure 5 This is a schematic diagram illustrating the information interaction between the main control system and the three-sided converter in a control method for a wind turbine generator according to an exemplary embodiment of the present disclosure.

[0024] Figure 6 This is a schematic diagram illustrating the control strategy of the generator-side converter in a control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0025] Figure 7 This is a schematic diagram illustrating the control strategy of the grid-side converter in a control method for a wind turbine generator according to an exemplary embodiment of the present disclosure.

[0026] Figure 8 This is a schematic diagram illustrating the control strategy of the energy storage converter in a control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0027] Figure 9 This is a schematic diagram illustrating a simulation system employing a control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0028] Figures 10 to 21This is a schematic diagram of simulation results illustrating an example of a control method for a wind turbine generator set employing an exemplary embodiment of the present disclosure.

[0029] Figures 22 to 30 This is a schematic diagram of simulation results illustrating another example of a control method for a wind turbine generator set employing an exemplary embodiment of the present disclosure. Detailed Implementation

[0030] The following detailed embodiments are provided to aid the reader in gaining a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, and / or systems described herein will become apparent upon understanding this disclosure. For example, the order of operations described herein is merely illustrative and is not limited to those orders set forth herein, but may be changed as will become clear upon understanding this disclosure, except for operations that must occur in a specific order. Furthermore, for clarity and conciseness, descriptions of features known in the art may be omitted.

[0031] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are provided only to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein, which will become clear upon understanding the disclosure of this application.

[0032] As used herein, the term “and / or” includes any one of the associated listed items and any combination of any two or more.

[0033] Although terms such as “first,” “second,” and “third” may be used herein to describe various components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts should not be limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Thus, without departing from the teaching of the examples described herein, the first component, first assembly, first region, first layer, or first part referred to as the first component, first assembly, first region, first layer, or first part may also be referred to as the second component, second assembly, second region, second layer, or second part.

[0034] In the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to," or "bonded to" another element, the element may be directly "on" another element, directly "connected to," or "bonded to" the other element, or one or more other elements may be present in between. Conversely, when an element is described as being "directly on" another element, "directly connected to," or "directly bonded to" another element, no other elements may be present in between.

[0035] The terminology used herein is for the purpose of describing various examples only and is not intended to limit disclosure. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. The terms “comprising,” “including,” and “having” indicate the presence of the described features, quantities, operations, components, elements, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0036] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains upon understanding this disclosure. Unless expressly defined herein, terms (such as those defined in a general dictionary) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field and in this disclosure, and shall not be interpreted in an idealized or overly formalistic manner.

[0037] Furthermore, in the description of the examples, detailed descriptions of well-known related structures or functions will be omitted when it is believed that such detailed descriptions would lead to a vague interpretation of this disclosure.

[0038] As mentioned earlier, the relevant control schemes suffer from a lack of flexibility and a single control method for energy storage devices.

[0039] For example, traditional grid-connected wind power technology based on phase-locked loops (PLLs) suffers from a lack of inertia and primary frequency regulation response, highlighting frequency stability issues in new power systems. To address this problem, grid-connected control was proposed, aiming to provide wind farms with response characteristics similar to synchronous generators. However, the realization of grid-connected wind power functionality relies on sufficient energy reserves, and the significant uncertainty and volatility of wind farm power capture become the main factors limiting the performance of grid-connected wind power technology in achieving its intended response characteristics.

[0040] Although equipping wind farms with energy storage devices has become a major trend in the industry and is expected to provide energy reserves for grid-connected wind power technology, the energy storage devices in wind farms are mainly connected to the AC grid independently, making it difficult to achieve efficient and flexible coordination with individual wind turbine generators.

[0041] In view of the above problems, this disclosure provides a control method for a wind turbine generator set, a computer device, a wind turbine generator set, and a computer-readable storage medium to solve or at least alleviate the above problems.

[0042] According to a first aspect of an exemplary embodiment of the present disclosure, a control method for a wind turbine generator set is provided. This control method can be executed by the control system of the wind turbine generator set or the wind farm, for example, by the main control system of the wind turbine generator set.

[0043] In one example application scenario, a wind turbine generator set may include an energy storage device and an energy storage converter. One end of the energy storage converter is connected to the DC bus of the wind turbine generator set, and the other end of the energy storage converter is connected to the energy storage device. The control system executing this method can determine the current energy storage level of the energy storage device of the wind turbine generator set, and can control the energy storage device to charge or discharge according to the operating requirements of the wind turbine generator set in response to the current energy storage level being within a preset operating range. In response to the current energy storage level being outside the preset operating range, the control system can control the energy storage device to charge or discharge according to the degree to which the current energy storage level deviates from the preset operating range.

[0044] According to the control scheme of the wind turbine generator set disclosed herein, under the premise of taking into account the actual energy storage state of the energy storage device while considering the operating requirements of the wind turbine generator set, the relationship between the state of the energy storage device itself and the operating state of the generator set can be balanced, the charging and discharging process of the energy storage device can be flexibly controlled, the energy storage control can be optimized, and thus the control effect of the whole machine can be improved.

[0045] Before describing embodiments of the control method for wind turbine generators, an example of a power generation system in which the method can be implemented is first described here.

[0046] As an example, this method can be applied to, for example, Figure 1 The wind turbine generator set shown can be a full-power permanent magnet direct-drive wind turbine generator set with DC-side energy storage, and it can have an integrated wind and energy storage system. Specifically, the wind turbine generator set can include a wind turbine generator 110, a machine-side converter 120, a grid-side converter 130, an energy storage converter 140, and an energy storage device 150.

[0047] The wind turbine 110 can convert mechanical energy from the rotor into electrical energy, and the generator-side converter 120 converts this electrical energy (e.g., as shown in the image). Figure 1 As shown, it can convert AC power to DC power and output the converted power to the grid-side converter 130. The grid-side converter 130 can convert the received power (e.g., ...). Figure 1 As shown, it can convert direct current (DC) to alternating current (AC) and output it to the power grid. One end of the energy storage converter 140 can be connected to the DC bus of the wind turbine generator set, and the other end can be connected to the energy storage device 150 to convert and output electrical energy from the DC bus or from the energy storage device.

[0048] Although the above is Figure 1 An example structure of a wind turbine generator set applying this method is described, but it is not limited to this; the wind turbine generator set can also have other structures.

[0049] The following will refer to Figures 2 to 8A control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure is described. The wind turbine generator set may include an energy storage device and an energy storage converter. One end of the energy storage converter may be connected to the DC bus of the wind turbine generator set, and the other end of the energy storage converter may be connected to the energy storage device, such as... Figure 2 As shown, the control method for this wind turbine generator set may include the following steps:

[0050] In step S210, the current energy storage level of the energy storage device can be determined.

[0051] Specifically, during the operation of wind turbine generators, the power imbalance between the generator-side converter and the grid-side converter may cause changes in the DC bus voltage. In this case, DC bus voltage control can be implemented by controlling the energy storage converter. This allows the energy storage device to absorb excess power or support insufficient power through charging and discharging, thereby improving grid control capabilities and maintaining grid-side power stability as much as possible. During this process, the energy storage level of the energy storage device may change; therefore, its current energy storage level should be determined before controlling it.

[0052] As an example, energy storage levels can be expressed as a relative quantity, such as the ratio of current stored energy to the total capacity of the energy storage device (e.g., percentage). Alternatively, energy storage levels can also be expressed as an absolute quantity, such as the current remaining stored energy.

[0053] In step S220, in response to the current energy storage level being within a preset operating range, the energy storage device can be controlled to charge or discharge according to the operating requirements of the wind turbine generator. In step S230, in response to the current energy storage level being outside the preset operating range, the energy storage device can be controlled to charge or discharge according to the degree to which the current energy storage level deviates from the preset operating range.

[0054] Specifically, the current energy storage level can be compared with a preset operating range. When the current energy storage level is within the preset operating range, it can be considered to be in a normal operating state capable of supporting the operation of the wind turbine generator, such as absorbing or supporting power. When the current energy storage level is outside the preset operating range, it can be considered that the current energy storage level may deviate from the normal operating range. For example, the stored energy of the energy storage device may be too high or too low, or even close to the energy storage limit (upper limit or no energy storage state). In this case, according to the degree to which the current energy storage level deviates from the preset operating range, corresponding control strategies can be implemented to charge or discharge the energy storage device while meeting the operating requirements of the wind turbine generator as much as possible, restoring its stored energy to the preset operating range.

[0055] In step S220 above, it is not necessary to additionally initiate the charging and discharging procedure for the energy storage device. Here, the preset operating range can be determined according to actual control needs. For example, it can be determined based on whether the energy storage level within this preset operating range can ensure that the grid-side converter reliably fulfills the predetermined grid frequency support. An example method for determining the preset operating range will be described in detail below.

[0056] In step S230 above, the degree to which the current energy storage level deviates from the preset operating range can be determined first.

[0057] As an example, the energy storage level of the energy storage device can be pre-defined into ranges to represent the degree to which the energy storage level deviates from the preset operating range.

[0058] For example, the energy storage range of an energy storage device may include the aforementioned preset working range, first range, and second range. Here, the preset working range can be the energy storage range within which the energy storage device can normally support the operation of the unit, and the degree to which the second range deviates from the preset working range can be greater than the degree to which the first range deviates from the preset working range.

[0059] Here, the first range and the second range can be determined according to actual control needs. Examples of how to determine the first range and the second range will be described in detail below.

[0060] Based on the first range and the second range, in step S230, the energy storage device can be controlled to charge or discharge in the following ways: in response to the current energy storage level being in the first range that deviates from the preset operating range, the energy storage device is controlled to charge or discharge according to the operating status of the wind turbine generator; in response to the current energy storage level being in the second range that deviates from the preset operating range, the energy storage device is controlled to charge or discharge according to the energy storage demand of the energy storage device.

[0061] Specifically, since the second range may deviate from the preset operating range to a greater extent than the first range, the second range may be closer to the limit energy storage capacity of the energy storage device than the first range.

[0062] For example, such as Figure 3 As shown, the first range may include a preset discharge range and a preset charging range, and the second range may include an emergency discharge range and an emergency charging range. The emergency discharge range deviates from the normal operating range to a greater extent than the preset discharge range, and the emergency charging range deviates from the normal operating range to a greater extent than the preset charging range. The emergency discharge range may approach (e.g., include) the maximum energy storage capacity of the energy storage device, and the emergency charging range may approach (e.g., include) the energy storage device's no-energy-storage state.

[0063] Using the above method, when the energy storage level is in the first range, which is relatively close to the normal operating range, the energy storage level has not yet approached the energy storage limit. Therefore, the operating status of the wind turbine generator can be prioritized to control the energy storage device in order to meet the unit's needs as much as possible. When the energy storage level is in the second range, which is further away from the normal operating range, the energy storage level may be closer to the energy storage limit. Therefore, charging or discharging can be prioritized according to the energy storage demand to ensure the performance of the energy storage device itself and avoid damage to the energy storage device when it reaches its limit.

[0064] As an example, when the current energy storage level is within the first range, in response to the wind turbine being in primary frequency regulation, the energy storage device can be controlled to charge or discharge according to the power demand of primary frequency regulation to provide power support for primary frequency regulation; in response to the wind turbine not being in primary frequency regulation, the energy storage device can be controlled to charge or discharge according to the energy storage demand of the energy storage device to keep the energy storage level of the energy storage device within the preset operating range.

[0065] Specifically, with Figure 3 For example, when the energy storage level is within the preset charging or discharging range, the main control system can query the primary frequency regulation information of the grid-side converter at this time.

[0066] For example, if the primary frequency modulation power P f Less than the preset minimum threshold P f_off_criterion And it lasted for the threshold time T. f_off If the threshold value P is not specified, it is considered not to be in a primary frequency modulation state; otherwise, it is considered to be in a primary frequency modulation state. Here, the minimum threshold P is... f_off_criterion This can indicate the degree to which the frequency modulation power deviates from the rated power, and the duration T during which the power does not reach the threshold, whether the power is less than or greater than or equal to the threshold. f_off In the case where frequency modulation is not performed once, and the duration is greater than or equal to the threshold and reaches the threshold time T, then frequency modulation can be skipped. f_off In this case, frequency modulation can be performed once.

[0067] If the energy storage device is not in primary frequency regulation mode, it is not currently in grid-supported mode. In this case, the main control system can send charging or discharging information to the grid-side converter to charge or discharge the energy storage device, bringing the energy storage level back to the normal operating range. As an example, the primary frequency regulation function of the grid-side converter can be locked during charging or discharging of the energy storage device. Furthermore, after receiving charging or discharging information from the main control system, the grid-side converter can add (in discharging mode) or subtract (in charging mode) a preset charging or discharging power setpoint P from the original reference power operating point given by the main control system. c An example control strategy for the grid-side converter will be described in detail below.

[0068] If the device is in primary frequency regulation mode, it is currently in grid support mode. In this case, the device can be temporarily not charged or discharged to allow it to continue supporting primary frequency regulation until the energy storage level exceeds the first range and enters the second range or primary frequency regulation is completed.

[0069] By using the above method, when the energy storage level is in the first range, the current working status of the energy storage device can be determined based on whether the unit is in the primary frequency regulation state. This can avoid blindly charging and discharging the energy storage device, which would lead to the interruption of the primary frequency regulation, and can make full use of the idle time of the energy storage device to restore its energy storage level, so as to better support the next unit operation.

[0070] As an example, when the current energy storage level is in the second range, the energy storage device can be controlled to charge or discharge according to the amount of deviation of the current energy storage level from the preset operating range, so as to keep the energy storage level of the energy storage device within the preset operating range.

[0071] Specifically, with Figure 3 For example, when the energy storage level is in the emergency charging or discharging range, the main control system can immediately send a charging or discharging command to the grid-side converter. At this time, the grid-side converter can disable the primary frequency regulation function. That is, regardless of whether it is in the primary frequency regulation state at this time, the energy storage level needs to be restored first until it returns to the first range or the normal operating range.

[0072] This situation serves as an emergency control to ensure safety. Although in actual operation, it is generally only triggered in special circumstances such as encountering large-scale disturbances and the failure of the Automatic Generation Control (AGC) to act in a timely manner, and the probability of triggering is very small, it can serve as a guarantee for sudden emergencies and prevent damage to the energy storage device caused by extreme operating conditions.

[0073] Furthermore, as an example, when charging and discharging an energy storage device, the charging and discharging process can be terminated based on preset charging and discharging end levels. Specifically, charging can be terminated when the energy storage level is higher than the charging end level during the charging process; and discharging can be terminated when the energy storage level is lower than the discharging end level during the discharging process. Here, the charging and discharging end levels can be set according to actual needs; for example, both can be set within preset operating ranges. Figure 3 As shown, the charging end level can be close to the lower limit of the preset working range, and the discharging end level can be close to the upper limit of the preset working range. However, it is not limited to these values ​​and can also be set to other values, such as the middle value of the preset working range for both.

[0074] The above process can also be judged and controlled by the main control system. After the charging or discharging signal is triggered, if the energy storage level is higher than the charging end line or lower than the energy storage level defined by the discharging end line, the main control system can reset the charging or discharging signal and end the charging or discharging. In this case, the reference power operating point of the grid-side converter is restored to the mode given by the predicted value, and the lockout of the primary frequency regulation function is released.

[0075] The above describes the process of coordinating the charging and discharging of the energy storage device through the grid-side converter, taking into account the operation of the wind turbine generator and the energy storage level of the energy storage device. The following will describe an example of determining the power configuration and energy configuration of the energy storage device based on the above ideas.

[0076] The power configuration of energy storage devices can be determined based on the requirements for mitigating fluctuating power demand and power regulation.

[0077] Here, the power demand for smoothing fluctuations can be the power demand for smoothing wind power fluctuations, and the power regulation demand can be the power demand for energy storage devices to provide power regulation to the grid.

[0078] Specifically, the maximum power configuration of energy storage devices can be considered from two aspects. One aspect is that the energy storage device needs to mitigate wind power fluctuations. Here, the power requirement for mitigating fluctuations can be, for example, the maximum power P for mitigating fluctuations. w_max Therefore, the reference power operating point of the grid-side converter can be located at ±P of the reference power operating point of the generator-side converter. w_max Within this range (which will be described in detail below). On the other hand, it considers that the energy storage device needs to provide the power required by the grid side, such as the power required for the grid-side converter to perform virtual inertia and primary frequency regulation. Here, the power requirement providing the power conditions could be, for example, the maximum inertia, the primary frequency regulation power P. f_max .

[0079] Since the power capacity for smoothing fluctuating power demand and power regulation demand are used independently in the control design, in order to ensure the reliability of operation under complex conditions (such as when both power demands exist simultaneously), the maximum power configuration of the energy storage device can be P. w_max +P f_max .

[0080] Using the above method, the power configuration of the energy storage device can be determined based on two aspects of power demand, which can ensure that the energy storage device can still provide reliable support for the operation of the unit under complex operating conditions.

[0081] The following describes an example process for determining the energy configuration of an energy storage device and the various ranges of energy storage levels.

[0082] As an example, the preset operating range can be determined by ensuring that the energy storage device's first energy configuration within the preset operating range meets the energy requirements for providing power regulation support to the grid a preset number of times.

[0083] Specifically, the first energy configuration of the energy storage device within the upper and lower limits of its preset operating range can meet the energy requirements for providing power regulation support to the grid for a preset number of times. For example, with Figure 3 For example, the upper limit of the preset working range can be the first upper limit ( Figure 3 The upper limit of the preset working range is 1), and the lower limit of the preset working range can be the first lower limit ( Figure 3 The lower limit 1).

[0084] The energy stored by the energy storage device within the range of the upper limit 1 to the lower limit 1 (i.e., the preset operating range, which can also be considered the normal operating range) is E. 11 It can meet the energy requirements for fully participating in N preset power adjustments at maximum frequency modulation power, such as meeting the requirements for N primary frequency modulations. For example, if the preset maximum power for primary frequency modulation is P... f_max In this case, the energy storage capacity E 11 It can be expressed by the following equation (1):

[0085]

[0086] Where T1 is the time to start a frequency modulation operation after the disturbance occurs, and T2 is the time to complete a frequency modulation operation after the disturbance occurs. Here, N can be an integer greater than or equal to 1, and its value can be determined according to actual needs.

[0087] As an example, the first range may include a first discharge range and a first charge range, for example, it may correspond to... Figure 3 The preset discharge range and preset charging range are defined in the following manner. In this case, the first discharge range and the first charging range can be determined by ensuring that both the second energy configuration of the energy storage device in the first discharge range and the third energy configuration in the first charging range meet the energy requirements for providing primary power regulation support to the power grid.

[0088] Specifically, the second energy configuration of the energy storage device between the first upper limit and the upper limit of the first discharge range, and the third energy configuration between the first lower limit and the lower limit of the first charging range, can both meet the energy requirements for providing primary power regulation support to the power grid. For example, with Figure 3 For example, the first discharge range can be based on a first upper limit and a second upper limit higher than the first upper limit. Figure 3 The upper limit 2) is used to determine the first charging range, which can be based on the first lower limit and the second lower limit below the first lower limit. Figure 3 The lower limit 2) is used to determine this.

[0089] Furthermore, the second range may include a second discharge range above the second upper limit and a second charge range below the second lower limit, for example, it may correspond to... Figure 3 The emergency discharge range and emergency charging range are specified in the text. Figure 3 The upper limit 2 and lower limit 2 in the above can be set for the safety and normal operation of the energy storage device. For example, the stored energy cannot be lower than 5% and cannot be higher than 95%. Once this limit is reached, the charging and discharging program of the energy storage device must be started immediately to avoid damage to the energy storage device. The upper limit 1 and lower limit 1 can be set to ensure that the grid-side converter can reliably support the predetermined grid frequency.

[0090] Still with Figure 3 For example, the energy storage capacity E is between the upper limit 2 and the upper limit 1 (i.e., the preset discharge range). 12 And the stored energy E between the lower limit 1 and the lower limit 2 (i.e., the preset charging range) 21 Each can meet the energy demand for a complete power regulation operation at maximum frequency modulation power, for example, meeting the demand for one primary frequency regulation operation. Energy storage capacity E 12 and energy storage E 21 It can be expressed by the following equation (2):

[0091]

[0092] With this energy configuration, it can be ensured that the energy storage device can support the power supply to the grid both within the normal operating range and the preset charge and discharge range. Even within the preset charge and discharge range, it can provide power support at least once to ensure the control capability of the grid.

[0093] As an example, energy storage devices may include supercapacitors or rechargeable batteries.

[0094] When the energy storage device includes a supercapacitor, the energy stored by the supercapacitor can be determined by its capacitance and voltage value. The energy stored is different at different voltages, so different voltage levels can represent different energy storage levels.

[0095] As an example, the first discharge range and the first charge range can be determined as follows: Based on the maximum withstand voltage of the supercapacitor, determine the upper limit voltage corresponding to the first discharge range (e.g., ...). Figure 3 The upper limit 2); based on the upper limit voltage corresponding to the first discharge range and the preset lower limit voltage corresponding to the first charging range (e.g., the upper limit 2); Figure 3The lower limit 2), first energy configuration, second energy configuration, and third energy configuration determine the capacitance of the supercapacitor and the lower limit voltage corresponding to the first discharge range (e.g., the lower limit 2), first energy configuration, second energy configuration, and third energy configuration. Figure 3 The lower limit 1) and the upper limit voltage corresponding to the first charging range (e.g., the upper limit 1) Figure 3 The upper limit is 1).

[0096] Specifically, as described above, the first energy configuration can be determined based on the supercapacitor's capacitance, the first upper limit voltage corresponding to the first upper limit, and the first lower limit voltage corresponding to the first lower limit. The second energy configuration can be determined based on the supercapacitor's capacitance, the first upper limit voltage, and the second upper limit voltage corresponding to the second upper limit. The third energy configuration can be determined based on the supercapacitor's capacitance, the first lower limit voltage, and the second lower limit voltage corresponding to the second lower limit.

[0097] Based on the above relationships, taking the above equation (2) as an example, the relationship between the capacitance and voltage of the supercapacitor and the first energy configuration, the second energy configuration and the third energy configuration can be expressed by the following equation (3):

[0098]

[0099] Where C is the capacitance of the supercapacitor, U max1 U is the first upper limit voltage. min1 U is the first lower limit voltage. max2 U is the second upper limit voltage. min2 This is the second lower limit voltage.

[0100] Here, the upper limit voltage corresponding to the first discharge range, i.e., the second upper limit voltage U, can be determined based on the maximum withstand voltage of the supercapacitor. max2 The preset lower limit voltage corresponding to the first charging range (i.e., the second lower limit voltage U) min2 The second lower limit voltage can be determined based on demand. For example, the possible value of the DC side voltage when facing impacts from wind or the power grid can be estimated, and the second lower limit voltage can be determined based on the possible value of the voltage. For example, the second lower limit voltage U can be obtained by the following formula (4). min2 :

[0101]

[0102] Among them, I ess_max This is the rated current of the energy storage converter.

[0103] Thus, based on the energy configuration relationship in equation (3) above, the second upper limit voltage U can be used as a basis. max2 Second lower limit voltage U min2The first energy configuration, second energy configuration, and third energy configuration determine the capacitance C of the supercapacitor and the lower limit voltage corresponding to the first discharge range (i.e., the first lower limit voltage U). min1 ) and the upper limit voltage corresponding to the first charging range (i.e., the first upper limit voltage U) max1 ).

[0104] Based on the above method, when using supercapacitors as energy storage devices, the capacitance of the supercapacitors and the configuration of each energy storage range can be determined, and guidance on setting up supercapacitors can be provided, thereby better supporting grid control.

[0105] When an energy storage device includes a rechargeable battery, the voltage of the rechargeable battery remains almost constant within its normal energy storage range. The stored energy of the rechargeable battery can be determined by its state of charge (SOC) and the total capacity of the battery. Different SOCs represent different stored energy levels; therefore, different SOCs can represent different energy storage levels. Here, SOC is also called remaining capacity and can be expressed as a percentage. For example, when SOC = 0, it means the battery is fully discharged; when SOC = 100%, it means the battery is fully charged.

[0106] As an example, the first discharge range and the first charge range of a rechargeable battery can be determined as follows: Based on the maximum safe capacity of the rechargeable battery, determine the upper limit ratio corresponding to the first discharge range (e.g., Figure 3 The upper limit 2); based on the upper limit ratio corresponding to the first discharge range and the preset lower limit ratio corresponding to the first charging range (e.g., the upper limit 2); Figure 3 The lower limit 2), the second energy configuration, and the third energy configuration determine the total capacity of the rechargeable battery and the lower limit ratio corresponding to the first discharge range (e.g., the lower limit 2), the second energy configuration, and the third energy configuration, respectively. Figure 3 The lower limit 1) and the upper limit ratio corresponding to the first charging range (e.g., the ... Figure 3 The upper limit is 1).

[0107] Specifically, as described above, the first energy configuration can be determined based on the total capacity of the rechargeable battery, the first upper limit ratio corresponding to the first upper limit, and the first lower limit ratio corresponding to the first lower limit; the second energy configuration can be determined based on the total capacity of the rechargeable battery, the first upper limit ratio, and the second upper limit ratio corresponding to the second upper limit; and the third energy configuration can be determined based on the total capacity of the rechargeable battery, the first lower limit ratio, and the second lower limit ratio corresponding to the second lower limit.

[0108] Based on the above relationships, taking the above equation (2) as an example, the relationship between the total capacity and capacity ratio of the rechargeable battery and the first energy configuration, the second energy configuration, and the third energy configuration can be expressed by the following equation (5):

[0109]

[0110] Among them, E rated SOC is the total capacity of the rechargeable battery. max1 As the first upper limit ratio, SOC min1 As the first lower limit ratio, SOC max2 The second upper limit ratio, SOC min2 This is the second lower limit ratio.

[0111] Here, the upper limit ratio corresponding to the first discharge range can be determined based on the maximum safe capacity of the rechargeable battery, i.e., the second upper limit ratio SOC. max2 The preset lower limit ratio corresponding to the first charging range (i.e., the second lower limit ratio SOC) min2 The lower limit voltage can be determined based on demand. For example, the possible value of the DC side voltage when facing impacts from wind or the power grid can be estimated, and the second lower limit voltage can be determined based on this possible voltage value. Thus, according to the energy configuration relationship in equation (3) above, the second upper limit ratio SOC can be used as the basis for determining the lower limit voltage. max2 Second lower limit ratio SOC min2 The first energy configuration, the second energy configuration, and the third energy configuration determine the maximum safe capacity E of the rechargeable battery. rated The lower limit ratio corresponding to the first discharge range (i.e., the first lower limit ratio SOC) min1 ) and the upper limit ratio corresponding to the first charging range (i.e., the first upper limit ratio SOC) max1 ).

[0112] Based on the above method, when using rechargeable batteries as energy storage devices, the total capacity of the rechargeable batteries and the configuration of each energy storage range can be determined, and guidance on setting up rechargeable batteries can be provided, thereby better supporting grid control.

[0113] The above describes the configuration of the energy storage device and the setting of each energy storage range. The following will describe an example of coordinated control of the generator side, grid side and energy storage side.

[0114] As an example, such as Figure 4 As shown, the control method according to embodiments of this disclosure may further include the following steps:

[0115] In step S410, the first reference power for controlling the generator-side converter of the wind turbine generator set and the second reference power for controlling the grid-side converter of the wind turbine generator set can be determined.

[0116] In this step, to smooth out wind power fluctuations under normal operation, the main control system can determine the reference power operating point P for sending to the turbine-side converter based on the maximum power point tracking (MPPT) algorithm of the wind turbine generator.ref _ MSC (i.e., the first reference power), for example, the reference power operating point P. ref _ MSC The maximum power can be calculated using the maximum wind power tracking algorithm, which enables the turbine-side converter to perform maximum wind power tracking in order to make full use of wind energy.

[0117] As an example, the second reference power can be determined by performing time smoothing on the first reference power based on a preset time smoothing constant to obtain the second reference power.

[0118] For example, the main control system can set the reference power operating point P of the machine-side converter. ref _ MSC A low-pass filter is applied to obtain a smoothed power operating point, which is then used as the reference power operating point P sent to the grid-side converter. ref _ GSC (i.e., the second reference power). Here, due to the reference power operating point P of the generator-side converter... ref _ MSC The power output may fluctuate depending on wind speed fluctuations, and the power grid needs smooth and controllable output power. Therefore, by smoothing, the power fluctuations on the generator side caused by wind speed fluctuations can be eliminated as much as possible, thereby making the power output on the grid side more stable.

[0119] As an example, the second reference power can be obtained by time smoothing the first reference power using the following equation (6):

[0120]

[0121] Among them, T w T is the filtering time constant for power fluctuation suppression, which can be given according to actual needs. w The larger the value, the more significant the smoothing effect, and the more linear and stable the power becomes.

[0122] In step S420, the energy storage device can be controlled to charge or discharge based on the difference between the first reference power and the second reference power and a preset difference range, so as to provide power regulation support for smoothing the wind power fluctuation of the wind turbine generator.

[0123] Here, the preset difference range can represent the power range that smooths out wind power fluctuations.

[0124] Specifically, the maximum fluctuation power P for smoothing wind power fluctuations can be preset. w_max The second reference power of the grid-side converter can be within ±P of the first reference power of the generator-side converter. w_max Within the range. When the difference between the first reference power and the second reference power exceeds the preset difference range ±P w_maxExcess power (greater than +P) can be absorbed by controlling the charging or discharging of the energy storage device. w_max ") or provide power support (less than "-P w_max ”).

[0125] Through such coordinated control, the power fluctuations output by the generator to the grid are significantly suppressed by utilizing the buffering effect of the energy storage device, without affecting the wind energy capture efficiency.

[0126] The above reference Figures 2 to 3 The process of charging and discharging an energy storage device through grid-side converter control is described, and references are made to... Figure 4 The power coordination control process of the three-sided converter is described. These two aspects of coordination control can be executed separately or in combination, for example... Figure 5 An example of information interaction between the main control system and the three-sided converter is shown.

[0127] Specifically, such as Figure 5 As shown, during the interaction process, the main control system can send the reference power operating point P to the machine-side converter. ref _ MSC The main control system can also issue a reference power operating point P to the grid-side converter. ref _ GSC And the charging and discharging information of the energy storage device S charge The grid-side converter can report virtual inertia and primary frequency regulation power P to the main control system. f The main control system can receive the energy storage level (SOC) reported by the energy storage device. Here, based on the basic control of the three-sided converter, and based on, for example... Figure 5 The collaborative control technology of the three-sided converter shown relies on the upper-level main control system to coordinate and complete the control.

[0128] The following will refer to Figures 6 to 8 An example control strategy is used to describe the basic control of a three-sided converter.

[0129] Figure 6 An example of a control strategy for a machine-side converter is shown. The machine-side converter can perform generator power control. In a rotor-oriented rotating coordinate system, the output electromagnetic power of the wind turbine generator is controlled by controlling the quadrature-axis (q-axis) current, and field weakening control is performed by controlling the direct-axis (d-axis) current to avoid overmodulation of the converter at high speeds.

[0130] like Figure 6 As shown, the power command P of the machine-side converter ref_MSC Power measurement value P of the machine-side converter MSC The deviation between them is processed by a proportional-integral (PI) controller, which outputs the q-axis current component setpoint I. q_ref_MSCSimultaneously, the set value I of the d-axis current component output by the field weakening control of the generator terminal voltage is... d_ref_MSC Subsequently, the d-axis current component setting value and the q-axis current component setting value are compared with the corresponding d-axis current measurement value I. q_MSC q-axis current measurement value I d_MSC The deviation between them is processed by a PI controller and a cross-decoupling circuit, which outputs the d-axis component u of the modulated wave on the machine side. d_ref_MSC The q-axis component of the modulated wave on the machine side u q_ref_MSC After modulation, the output converter's drive signal is obtained, where ω r L represents the generator speed. s This indicates generator leakage inductance.

[0131] In the above process, field weakening control can be performed using the following formula (7):

[0132]

[0133] Among them, U MSCmax Ψ is the generator terminal voltage setpoint. f For generator flux linkage.

[0134] Figure 7 An example of a control strategy for an energy storage converter is shown. The energy storage converter can perform DC bus voltage control. The current reference value of the energy storage device is obtained from the outer loop of DC voltage control, and then the inner loop of energy storage current control controls the energy storage current by changing the duty cycle of the bidirectional DC / DC converter.

[0135] like Figure 7 As shown, the DC voltage setting value U dc_ref DC voltage measurement value U dc The deviation between them is processed by the PI controller to output the energy storage side current setpoint I. ess_ref Subsequently, it is compared with the energy storage side current feedback value I. ess The deviation between them is processed by the PI controller, which outputs the duty cycle D of the energy storage chopper. ess After modulation, the output chopper drive signal is generated.

[0136] Figure 8 An example of a control strategy for a grid-side converter is illustrated. The grid-side converter can perform virtual synchronous control, providing inertia and primary frequency regulation response to the grid. Virtual synchronous operation is achieved by fixing the phase of the grid-side converter's output modulation voltage to a constructed virtual rotor coordinate system to form a synchronous internal potential. The amplitude of the output modulation voltage is droop-controlled according to the amplitude of the GSC port voltage.

[0137] like Figure 8 As shown, the deviation between the rated angular frequency ω0 of the power grid and the internal potential angular frequency ω is controlled by droop (primary frequency regulation droop coefficient K).f and low-pass filtering After the circuit, the primary frequency modulation power P is output. f The externally given active power setpoint P of the grid-side converter. ref_GSC When superimposed with the primary frequency regulation power, the measured active power P on the grid side is... GSC The deviation, after passing through the virtual rotor motion equation, outputs the frequency and phase of the internal electromotive force, where D is the virtual damping coefficient, J is the virtual inertia time constant, and ω... s This is the grid angular frequency. On the other hand, the reactive power setpoint Q of the grid-side converter... ref_GSC The reactive power measurement value Q of the grid-side converter GSC The deviation between them is controlled by droop (reactive power droop coefficient K). u ) link and voltage feedforward (voltage feedforward value U) ref After that, the amplitude E of the internal potential is output. Finally, based on the amplitude and phase θ of the internal potential, the internal potential in the three-phase stationary coordinate system can be synthesized, where U... a_ref_GSC U is the phase component of the internal potential. b_ref_GSC U is the phase b component of the internal potential. c_ref_GSC The c-phase component represents the internal potential.

[0138] Figure 9 This is a schematic diagram illustrating a simulation system employing a control method for a wind turbine generator set according to an exemplary embodiment of the present disclosure.

[0139] like Figure 9 As shown, the wind turbine generator set can be a permanent magnet direct-drive integrated wind and energy storage grid-connected system, which includes a wind turbine generator 110, a turbine-side converter 120, a grid-side converter 130, an energy storage converter (not shown), an energy storage device 150, a box-type transformer T1, and a main transformer T2 for the power station. The grid side can include a synchronous generator SG and a step-up transformer T3. In the simulation, the rated capacity of the permanent magnet direct-drive wind turbine generator set can be set to 5MVA, the rated AC voltage to 0.69kV, and the rated DC bus voltage to 1200V. The three converters adopt... Figures 6 to 8 The control strategy is to achieve coordinated operation of the three converters through the aforementioned main control system's coordinated control strategy.

[0140] As an example, in Figure 9 In this system, load 1 can be 5MW and load 2 can be 1MW. The parameters of the transformer, line and synchronizing machine in the system are shown in Table 1 below.

[0141] Table 1

[0142]

[0143] Based on the above system parameters, the key parameters of the cooperative control strategy can be designed and calculated first. Specifically, assume the rated power S of the unit... N It can be 5MW, and P can be designed. f_max With P w_max Both are 10% S N If the power is 500kW, then the rated power of the energy storage is 1MW. The filtering time constant T between the reference power operating point of the generator-side converter and the reference power operating point of the grid-side converter is... w It can last for 5 seconds.

[0144] In this example, the energy storage device can be a supercapacitor, and the rated current of the energy storage converter can be 1875A. Thus, according to the above equation (4), the second lower limit voltage U of the energy storage device can be obtained. min2 =533V. The second upper limit voltage U of the supercapacitor. max2 =1000V. Here, we can take N=3, T1=30s, T2=600s, and from the above formula (3), we can calculate the supercapacitor capacitance C=2200F, U max1 =925V, U min1 =650V.

[0145] The charging and discharging power P of the grid-side converter c Take 2% S N That is, 100kW. The discharge end voltage is taken as 875V, and the charging end voltage is taken as 700V. P f The set minimum threshold P f_off_criterion Take 0.5% S N That is, 50kW, T f_off The value is set to 5s. The grid-side converter adopts the following... Figure 8 The virtual synchronous control shown below uses the relevant control parameters of the grid-side converter, as shown in Table 2.

[0146] Table 2

[0147]

[0148] The energy storage-side converter adopts, for example Figure 7 The control parameters are shown in Table 3 below.

[0149] Table 3

[0150]

[0151] The machine-side converter adopts, for example Figure 6 The control parameters are shown in Table 4 below.

[0152] Table 4

[0153]

[0154] The relevant parameters of the wind turbine and permanent magnet generator are shown in Table 5 below.

[0155] Table 5

[0156]

[0157] Based on the above simulation parameters, simulation results in several example scenarios were obtained using the control method of the wind turbine generator set according to the exemplary embodiments of this disclosure.

[0158] Figures 10 to 21 Simulation results are shown for verifying the power fluctuation suppression function of integrated wind and energy storage control using the method of embodiments of this disclosure.

[0159] like Figures 10 to 21 As shown, under conditions of fluctuating wind speed (such as...) Figure 20 and Figure 21 As shown), the output power of the machine-side converter can quickly and accurately track the power reference value determined by the MPPT, but there are significant fluctuations overall (e.g. Figures 10 to 13 as well as Figures 16 to 18 (As shown). Under the power fluctuation suppression and coordination control of the main control system, the output power of the grid-side converter is greatly smoothed (as shown). Figure 19 As shown, this can reduce fluctuations in the grid's output power.

[0160] The energy storage converter maintains the DC bus voltage within a very small range of fluctuation through DC bus voltage control. The unbalanced power between the generator side and the grid side is absorbed into the supercapacitor, which acts as an energy storage device, causing changes in the supercapacitor's voltage (e.g., ...). Figure 14 and Figure 15 (As shown). Here, the active power reference value of the grid-side converter may include the reference power operating point, primary frequency regulation power, and charging / discharging power issued by the main control system.

[0161] Figures 22 to 30 Simulation results are shown for simulating operation under load variation using the method of embodiments of the present disclosure. In this simulation, load 2 is connected to the grid at 5s and disconnected from the grid at 25s. In order to demonstrate the effectiveness of charge and discharge control in a shorter simulation time, the energy storage device capacitor is reduced to 30F in this simulation.

[0162] like Figures 22 to 30 As shown, under conditions of fluctuating wind speed (such as...) Figure 29 and Figure 30 As shown), after load 2 is connected, the system frequency drops, and the grid-side converter of the wind turbine immediately increases its output power under the action of virtual synchronization control (e.g., Figure 22 and Figure 23As shown in the diagram, it provides inertial response to the system and continues to provide active power support under subsequent primary frequency regulation control. Simultaneously, the energy storage voltage of the supercapacitor decreases and exceeds U0. min1 =650V limit (e.g.) Figure 27 (As shown).

[0163] After load 2 is disconnected, the system frequency rises, the output power of the grid-side converter of the wind turbine generator decreases, and the primary frequency regulation power P... f It gradually decreases to near 0. The main control system, after analyzing the current energy storage voltage and P... f After comprehensive judgment, the charging signal is set to 1 to issue a charging command to the grid-side converter (e.g., Figure 26 As shown), the grid-side converter lowers the active power reference value P based on the reference power operating point. c Simultaneously, the primary frequency regulation function is locked. The supercapacitor's energy storage voltage gradually recovers, and when it reaches 700V, charging ends. The main control system resets the charging signal to 0, the active power reference value of the grid-side converter returns to the reference power operating point, and the primary frequency regulation function is unlocked. Throughout the process, the generator-side converter control remains unaffected, consistently capturing wind power (e.g., according to the MPPT power operating point) as wind speed changes. Figure 28 (As shown).

[0164] The control method according to embodiments of this disclosure proposes a cooperative control strategy for three-sided converters and provides principles for energy storage device capacity configuration. This strategy aims to suppress wind power fluctuations, stabilize the internal DC bus voltage, support inertia and primary frequency regulation, and manage the charging and discharging of the energy storage device. This three-sided converter cooperative control technology offers advantages such as high cooperative efficiency, fast response speed, and strong support capabilities, ensuring the reliable operation of the entire wind turbine unit.

[0165] Furthermore, the control method described above according to the embodiments of this disclosure can integrate the control of the energy storage device into the overall operation control of the grid-connected wind turbine generator set, thereby improving the operational flexibility of the wind turbine generator set and providing energy reserves for grid-connected control.

[0166] According to a second aspect of this disclosure, a computer device is provided, the computer device comprising: at least one processor; at least one memory storing computer-executable instructions, wherein the computer-executable instructions, when executed by the at least one processor, cause the at least one processor to perform a control method for a wind turbine generator according to an exemplary embodiment of this disclosure.

[0167] As an example, computer equipment can be installed in the wind turbine generator set, or the computer equipment can be connected to the control system of the wind turbine generator set.

[0168] As an example, a computer device can be a PC, tablet, personal digital assistant, smartphone, or other device capable of executing the aforementioned set of instructions. Here, a computer device is not necessarily a single electronic device, but can be any collection of devices or circuits capable of executing the aforementioned instructions (or instruction sets) individually or in combination. A computer device can also be part of an integrated control system or system manager, or can be configured to interface with a portable electronic device locally or remotely (e.g., via wireless transmission).

[0169] In computer devices, a processor may include a central processing unit (CPU), a graphics processing unit (GPU), a programmable logic device, a dedicated processor system, a microcontroller, or a microprocessor. By way of example and not limitation, a processor may also include an analog processor, a digital processor, a microprocessor, a multi-core processor, a processor array, a network processor, etc.

[0170] The processor can execute instructions or code stored in memory, which can also store data. Instructions and data can also be sent and received over a network via a network interface device, which can employ any known transport protocol.

[0171] Memory can be integrated with the processor; for example, RAM or flash memory can be housed within an integrated circuit microprocessor. Alternatively, memory can comprise a separate device, such as an external disk drive, storage array, or other storage device that can be used by any database system. Memory and processor can be operatively coupled, or can communicate with each other, for example, via I / O ports, network connections, etc., enabling the processor to read files stored in the memory.

[0172] In addition, computer equipment may include video displays (such as liquid crystal displays) and user interaction interfaces (such as keyboards, mice, touch input devices, etc.). All components of a computer device may be interconnected via buses and / or networks.

[0173] According to a third aspect of this disclosure, a wind turbine generator set is provided, which may include the computer equipment described in embodiments of this disclosure.

[0174] According to a fourth aspect of this disclosure, a computer-readable storage medium is provided that, when instructions in the computer-readable storage medium are executed by at least one processor, causes the at least one processor to perform a control method for a wind turbine generator according to an exemplary embodiment of this disclosure.

[0175] The control method for a wind turbine generator set according to embodiments of the present disclosure can be programmed into a computer program and stored on a computer-readable storage medium. Examples of computer-readable storage media include: read-only memory (ROM), random access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile memory, CD-ROM, CD-R, CD+R, CD-RW, CD+RW, DVD-ROM, DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM, BD-ROM, BD-R, BD-R LTH, BD-RE, Blu-ray or optical disc storage, hard disk drive (HDD), solid-state drive (SSD), card storage (such as multimedia cards, secure digital (SD) cards, or ultra-fast digital (XD) cards), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state drive, and any other device configured to store a computer program and any associated data, data files, and data structures in a non-transitory manner and to provide the computer program and any associated data, data files, and data structures to a processor or computer so that the processor or computer can execute the computer program. In one example, the computer program and any associated data, data files, and data structures are distributed across a networked computer system, such that the computer program and any associated data, data files, and data structures are stored, accessed, and executed in a distributed manner through one or more processors or computers.

[0176] The specific embodiments of this disclosure have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that modifications and variations can be made to these embodiments without departing from the principles and spirit of this disclosure, which are defined by the claims and their equivalents. Such modifications and variations should also be within the protection scope of the claims of this disclosure.

Claims

1. A control method for a wind turbine generator set, characterized in that, The wind turbine generator set includes an energy storage device and an energy storage converter. One end of the energy storage converter is connected to the DC bus of the wind turbine generator set, and the other end of the energy storage converter is connected to the energy storage device. The control method includes: Determine the current energy storage level of the energy storage device; In response to the current energy storage level being within a preset operating range, the energy storage device is controlled to charge or discharge according to the operating requirements of the wind turbine generator set; In response to the current energy storage level being outside the preset operating range, the energy storage device is controlled to charge or discharge according to the degree to which the current energy storage level deviates from the preset operating range. The preset operating range is determined as follows: the preset operating range is determined by ensuring that a first energy configuration of the energy storage device within the preset operating range meets the energy demand for providing power regulation support to the power grid for a preset number of times. The first energy configuration is determined based on the time of a frequency regulation start-up, the time of a frequency regulation completion, the maximum frequency regulation power, and the preset number of times. The degree to which the current energy storage level deviates from the preset operating range includes the current energy storage level being within a first range of deviation from the preset operating range. This first range includes a first discharge range and a first charging range. The first discharge range and the first charging range are determined by ensuring that both a second energy configuration of the energy storage device within the first discharge range and a third energy configuration within the first charging range meet the energy requirements for providing primary power regulation support to the power grid. The second energy configuration and the third energy configuration are determined based on the time of the start of the first frequency modulation operation, the time of the completion of the first frequency modulation operation, and the maximum frequency modulation power.

2. The control method according to claim 1, characterized in that, The step of controlling the charging or discharging of the energy storage device based on the degree to which the current energy storage level deviates from the preset operating range includes: In response to the current energy storage level being in the first range deviating from the preset operating range, the energy storage device is controlled to charge or discharge according to the operating status of the wind turbine generator set; In response to the current energy storage level being in a second range deviating from the preset operating range, the energy storage device is controlled to charge or discharge according to its energy storage requirements. Wherein, the degree to which the second range deviates from the preset working range is greater than the degree to which the first range deviates from the preset working range.

3. The control method according to claim 2, characterized in that, The step of controlling the charging or discharging of the energy storage device according to the operating status of the wind turbine generator set includes: In response to the wind turbine being in primary frequency regulation mode, the energy storage device is controlled to charge or discharge according to the power demand of the primary frequency regulation, so as to provide power support for the primary frequency regulation. In response to the wind turbine generator not being in primary frequency regulation mode, the energy storage device is controlled to charge or discharge according to its energy storage requirements, so that the energy storage level of the energy storage device is within the preset operating range.

4. The control method according to claim 2, characterized in that, The step of controlling the charging or discharging of the energy storage device according to its energy storage requirements includes: Based on the deviation of the current energy storage level from the preset operating range, the energy storage device is controlled to charge or discharge, so that the energy storage level of the energy storage device is within the preset operating range.

5. The control method according to claim 1, characterized in that, The power configuration of the energy storage device is determined based on the requirements for mitigating fluctuating power demand and power regulation. The power demand for smoothing fluctuations refers to the power demand for smoothing wind power fluctuations, and the power regulation demand refers to the power demand for the energy storage device to provide power regulation to the power grid.

6. The control method according to claim 1, characterized in that, The energy storage device includes a supercapacitor, wherein determining the first discharge range and the first charging range includes: Based on the maximum withstand voltage of the supercapacitor, determine the upper limit voltage corresponding to the first discharge range; Based on the upper limit voltage corresponding to the first discharge range, the preset lower limit voltage corresponding to the first charging range, the first energy configuration, the second energy configuration, and the third energy configuration, the capacitance of the supercapacitor, the lower limit voltage corresponding to the first discharge range, and the upper limit voltage corresponding to the first charging range are determined.

7. The control method according to claim 1, characterized in that, The energy storage device includes a rechargeable battery, wherein determining the first discharge range and the first charging range includes: Based on the maximum safe capacity of the rechargeable battery, determine the upper limit ratio corresponding to the first discharge range; Based on the upper limit ratio corresponding to the first discharge range, the preset lower limit ratio corresponding to the first charging range, the second energy configuration, and the third energy configuration, the total capacity of the rechargeable battery, the lower limit ratio corresponding to the first discharge range, and the upper limit ratio corresponding to the first charging range are determined.

8. The control method according to claim 1, characterized in that, The control method further includes: Determine a first reference power for controlling the generator-side converter of the wind turbine generator set and a second reference power for controlling the grid-side converter of the wind turbine generator set; Based on the difference between the first reference power and the second reference power, and a preset difference range, the energy storage device is controlled to charge or discharge, providing power regulation support for smoothing wind power fluctuations in the wind turbine generator set. The preset difference range refers to the power range that smooths out wind power fluctuations.

9. The control method according to claim 8, characterized in that, The second reference power is determined in the following manner: Based on a preset time smoothing constant, the first reference power is subjected to time smoothing processing to obtain the second reference power.

10. A computer device, characterized in that, The computer device includes a processor and memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the control method of the wind turbine generator set according to any one of claims 1-9 according to the instructions in the program code.

11. A wind turbine generator set, characterized in that, The wind turbine generator set includes the computer equipment according to claim 10.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program or instructions that, when executed by a processor, implement the control method for a wind turbine generator set according to any one of claims 1-9.

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