Wind power generation system and control method thereof

Abstract

The invention provides a wind power generation system and a control method thereof, and relates to the technical field of wind power generation. The method comprises the following steps: taking the average output power of a wind turbine generator set in a previous preset control time period as a smooth output reference power value; determining the maximum discharge power and the maximum charge power of the energy storage device in the current control time period based on the charge state of the battery unit; determining a deviation value between the smooth output reference power value and the actual output power of the wind turbine generator in the current control time period; and comparing the deviation value with the maximum discharging power and the maximum charging power, determining the charging and discharging target power of the energy storage device, and performing charging and discharging control on the energy storage device. According to the invention, the stability of wind power output can be greatly improved, and the harmonic content is reduced, so that the wind power is closer to transmission energy. Therefore, the wind power with unstable output can better participate in the scheduling arrangement of the power grid, the competitiveness of the wind power plant in the power market is improved, and the large-scale grid connection and consumption of the wind power are promoted.

Description

Technical Field

[0001] The present disclosure relates to the technical field of wind power generation, and in particular to a wind power generation system and a control method thereof. Background Art

[0002] As a green and renewable energy, wind power is gradually becoming an important part of the energy structure. Different from conventional energy (such as thermal power and hydropower), wind power has the characteristics of randomness, volatility and intermittence, and the output of wind power is unstable. With the large-scale grid connection of wind power, it will inevitably bring challenges to the dispatching and stable operation of the power grid. Summary of the invention

[0003] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the first aspect of the present disclosure provides a control method for a wind power generation system, wherein the wind power generation system comprises: a wind turbine, a converter, a box-type transformer and an energy storage device, wherein the energy storage device comprises a battery unit, the wind turbine, the converter and the box-type transformer are connected in sequence, and the energy storage device is connected in parallel to the DC bus side of the converter; the method comprises the following steps:

[0005] Acquire the average output power of the wind turbine generator set in a previous preset control time period, and determine the average output power as a smoothed output reference power value of the wind turbine generator set in a current control time period;

[0006] Determining the maximum discharge power and the maximum charge power of the energy storage device in the current control time period based on the state of charge of the battery unit;

[0007] Determine a deviation value between the smoothed output reference power value and the actual output power of the wind turbine generator set during the current control time period;

[0008] Comparing the deviation value with the maximum discharge power and the maximum charge power, and determining the charge and discharge target power of the energy storage device based on the comparison result;

[0009] The energy storage device is controlled to be charged and discharged according to the charge and discharge target power.

[0010] In some embodiments of the present disclosure, determining the maximum discharge power and the maximum charging power of the energy storage device in the current control time period based on the state of charge of the battery cell includes: determining the discharge coefficient and the charging coefficient of the energy storage device according to the state of charge of the battery cell; determining the maximum discharge power according to the discharge coefficient and the rated charge and discharge power of the energy storage; determining the maximum charging power according to the charging coefficient and the rated charge and discharge power of the energy storage.

[0011] In some embodiments of the present disclosure, the deviation value is compared with the maximum discharge power and the maximum charging power, and the charge and discharge target power of the energy storage device is determined based on the comparison result, including: in response to the deviation value being greater than or equal to the maximum charging power, and less than or equal to the maximum discharge power, determining the deviation value as the charge and discharge target power; or, in response to the deviation value being greater than the maximum discharge power, determining the maximum discharge power as the charge and discharge target power; or, in response to the deviation value being less than the maximum charging power, determining the maximum charging power as the charge and discharge target power.

[0012] In some embodiments of the present disclosure, the further step includes: determining a smoothed output reference power value of the wind turbine set in a next control time period based on the comparison result and the smoothed output reference power value.

[0013] In some embodiments of the present disclosure, determining the smoothed output reference power value of the wind turbine group in the next control time period based on the comparison result includes: in response to the deviation value being greater than or equal to the maximum charging power and less than or equal to the maximum discharge power, determining the smoothed output reference power value as the smoothed output reference power value of the wind turbine group in the next control time period; or, in response to the deviation value being greater than the maximum discharge power, determining a smoothed output reference power decrease transformation coefficient according to the state of charge, and determining the smoothed output reference power value of the wind turbine group in the next control time period according to the smoothed output reference power decrease transformation coefficient and the smoothed output reference power value; or, in response to the deviation value being less than the maximum charging power, determining a smoothed output reference power increase transformation coefficient according to the state of charge, and determining the smoothed output reference power value of the wind turbine group in the next control time period according to the smoothed output reference power increase transformation coefficient and the smoothed output reference power value.

[0014] In some embodiments of the present disclosure, in response to the deviation value being greater than the maximum discharge power, the smoothed output reference power reduction conversion coefficient is determined by the following formula:

[0015]

[0016] Wherein, k1(j) is the smoothed output reference power down conversion coefficient, SOC B,i is the state of charge, k0 is the basic coefficient of smooth output reference power conversion;

[0017] The smoothed output reference power value is determined by the following formula:

[0018]

[0019] in, is the smoothed output reference power value of the wind turbine generator set in the next control time period, is the smoothed output reference power value, and ΔT is the control period step.

[0020] In some embodiments of the present disclosure, in response to the deviation value being less than the maximum charging power, the smoothed output reference power increase conversion coefficient is determined by the following formula:

[0021]

[0022] Wherein, k2(j) is the smooth output reference power increase conversion coefficient, SOC B,i is the state of charge, k0 is the basic coefficient of smooth output reference power conversion;

[0023] The smoothed output reference power value is determined by the following formula:

[0024]

[0025] in, is the smoothed output reference power value of the wind turbine generator set in the next control time period, is the smoothed output reference power value, and ΔT is the control period step.

[0026] The second aspect of the present disclosure provides a control device for a wind power generation system, wherein the wind power generation system comprises: a wind turbine, a converter, a box-type transformer and an energy storage device, wherein the energy storage device comprises a battery unit, wherein the wind turbine, the converter and the box-type transformer are connected in sequence, and the energy storage device is connected in parallel to the DC bus side of the converter; the device comprises:

[0027] An acquisition module, used for acquiring the average output power of the wind turbine set in a previous preset control time period, and determining the average output power as a smoothed output reference power value of the wind turbine set in a current control time period;

[0028] A first determination module, configured to determine a maximum discharge power and a maximum charge power of the energy storage device in the current control time period based on the state of charge of the battery unit;

[0029] A second determination module is used to determine a deviation value between the smoothed output reference power value and the actual output power of the wind turbine generator set in the current control time period;

[0030] A third determination module, configured to compare the deviation value with the maximum discharge power and the maximum charge power, and determine a charge and discharge target power of the energy storage device based on the comparison result;

[0031] A control module is used to control the charging and discharging of the energy storage device according to the charging and discharging target power.

[0032] The third aspect of the present disclosure provides a wind power generation system, including: a wind turbine, a converter, a box-type transformer and an energy storage device, wherein the energy storage device includes a battery unit;

[0033] The wind turbine, the converter and the box-type transformer are connected in sequence, and the energy storage device is connected in parallel to the DC bus side of the converter.

[0034] A fourth aspect of the present disclosure provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0035] The memory stores computer-executable instructions;

[0036] The processor executes the computer-executable instructions stored in the memory to implement the method described in the first aspect.

[0037] The control method of the wind power generation system provided by the present disclosure controls the charging and discharging of the energy storage device according to the deviation value between the smoothed output reference power value and the actual output power of the wind turbine set, and considers the charge state of the energy storage device, thereby greatly improving the stability of wind power output, reducing the harmonic content, and making it closer to the transmission energy. It enables wind power with unstable output to better participate in the dispatching arrangement of the power grid, improves the competitiveness of wind farms in the power market, and promotes the large-scale grid connection and consumption of wind power.

[0038] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present disclosure will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0040] Figure 1 A schematic diagram of a wind power generation system provided by an embodiment of the present disclosure;

[0041] Figure 2 A schematic flow chart of a control method for a wind power generation system provided by an embodiment of the present disclosure;

[0042] Figure 3 A schematic diagram of a converter control module at the machine side of a converter provided by an embodiment of the present disclosure;

[0043] Figure 4A schematic diagram of an energy storage DC-DC converter control module provided in an embodiment of the present disclosure;

[0044] Figure 5 A schematic diagram of a converter grid-side converter control module provided by an embodiment of the present disclosure;

[0045] Figure 6 A schematic diagram of a phase-locked loop control module provided by an embodiment of the present disclosure;

[0046] Figure 7 A schematic diagram of a control device for a wind power generation system provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] Embodiments of the present disclosure are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present disclosure, and should not be construed as limiting the present disclosure.

[0048] Specifically, the wind power generation system and the control method thereof according to the embodiments of the present disclosure are described below with reference to the accompanying drawings.

[0049] Figure 1 Schematic diagram of a wind power generation system provided by an embodiment of the present disclosure. Figure 1 As shown, the wind power generation system includes: a wind turbine 1 (including an impeller, a rotating chain and a generator), a converter 2, a box-type transformer 3 and an energy storage device 4. The energy storage device 4 includes: a battery unit 4-1, a DC-DC bidirectional converter 4-2 and a circuit breaker 4-3.

[0050] Among them, the wind turbine 1, the converter 2 and the box-type transformer 3 are connected in sequence. The converter 2 converts the electric energy generated by the wind turbine into electric energy with the same voltage, frequency and phase as the power grid through AC-DC-AC conversion. The converter 2 includes a machine-side converter 2-1, a DC bus and capacitor 2-2, a grid-side converter 2-3, and a grid-connected circuit breaker 2-4. The low-voltage side 690V of the box-type transformer 3 is connected to the converter grid-connected circuit breaker 2-4, and the high-voltage side 35kV of the box-type transformer 3 is connected to the wind farm collection line to supply power to the power grid. The energy storage device 4 is connected in parallel to the DC bus side 2-2 in the converter. It should be noted that a wind farm may include multiple wind turbines. Figure 1 Take only one wind turbine as an example. For each wind turbine, an energy storage device is connected in parallel on the DC bus side of its corresponding converter.

[0051] Since the energy storage device 4 is connected in parallel to the DC bus side of the converter and shares the converter 2-3 with the converter 2 to convert AC power into DC power, there is no need to set up a separate inverter for the energy storage device 4, thereby saving energy storage inverters and reducing equipment costs.

[0052] Figure 2 A flow chart of a control method for a wind power generation system provided by an embodiment of the present disclosure. Figure 1 The embodiment shown. Figure 2 As shown, the control method of the wind power generation system may include the following steps:

[0053] Step 201 : obtaining the average output power of the wind turbine generator set in a previous preset control time period, and determining the average output power as a smoothed output reference power value of the wind turbine generator set in a current control time period.

[0054] As an example, each control time period can be set to 1 minute, and the average output power of the wind turbine in the previous 10 minutes can be counted to obtain the smoothed output reference power value of the wind turbine in the current control time period. In one embodiment, the smoothed output reference power value of the wind turbine in the current control time period can be expressed as follows:

[0055]

[0056] in, is the smoothed output reference power value of wind turbine i in the current control time period j, P ini,i is the average output power of wind turbine i in the previous preset control time period, P W,i (jm) is the average output power of wind turbine i during the control time period (jm).

[0057] Step 202 : determining the maximum discharge power and the maximum charge power of the energy storage device in the current control time period based on the charge state of the battery unit.

[0058] The state of charge of the battery cell can represent the charge and discharge capability of the energy storage device. In some embodiments of the present disclosure, the discharge coefficient and charge coefficient of the energy storage device can be determined according to the state of charge of the battery cell. max Determine the maximum discharge power according to the charging coefficient and the energy storage rated charge and discharge power P max Determine the maximum charging power. The discharge coefficient and charging coefficient can be expressed as follows:

[0059]

[0060] Among them, K B,i is the charge and discharge limit coefficient of the energy storage device, K B_d,iis the discharge coefficient of the energy storage device, K B_c,i is the charging coefficient of the energy storage device, SOC B,i The state of charge of the battery cell.

[0061] The maximum charge and discharge power of the energy storage device can be expressed as follows:

[0062]

[0063] in, is the maximum discharge power of the energy storage device in the current control time period j, is the maximum charging power of the energy storage device in the current control time period j, P max It is the rated charging and discharging power of the energy storage device.

[0064] Step 203: determine a deviation value between the smoothed output reference power value and the actual output power of the wind turbine generator set in the current control time period.

[0065] The deviation value can be expressed as follows:

[0066]

[0067] in, is the deviation value, is the smoothed output reference power value of wind turbine i in the current control time period j, is the actual output power of wind turbine i in the current control time period j.

[0068] Step 204 : compare the deviation value with the maximum discharge power and the maximum charge power, and determine the charge and discharge target power of the energy storage device based on the comparison result.

[0069] The deviation value is compared with the maximum discharge power and the maximum charging power, that is, the charging and discharging power of the energy storage device participating in the smooth output control of the wind turbine is determined according to the current charging and discharging capacity of the energy storage device.

[0070] In some embodiments of the present disclosure, if the deviation value is greater than or equal to the maximum charging power and less than or equal to the maximum discharging power The deviation value is determined as the charging and discharging target power of the energy storage device (Deviation value For positive time, is the discharge target power; deviation value When it is negative, is the charging target power).

[0071] If the deviation value is greater than the maximum discharge power The maximum discharge power is determined as the charge and discharge target power

[0072] If the deviation value is less than the maximum charging power The maximum charging power is determined as the charging and discharging target power

[0073] Step 205 , controlling the charging and discharging of the energy storage device according to the charging and discharging target power.

[0074] The wind turbine converter adopts the optimal power control strategy to achieve the goal of maximizing wind energy absorption. Figure 3 The control module of the converter at the machine side of the converter includes a generator rotor phase calculation module 10 , an optimal power operation control module 11 and a current inner loop control module 12 .

[0075] The input of the generator rotor phase calculation module 10 is the generator measured speed ω g , the output is the generator rotor phase θ g , the calculation formula is as follows:

[0076]

[0077] The optimal power operation control module 11 is composed of an optimal power control torque calculation 11-1 and a q-axis current control target value calculation 11-2. The optimal power control torque calculation 11-1 inputs the generator measured speed ω g , the output is the generator control target torque T * , the formula is as follows:

[0078]

[0079] In the formula, K opt is the optimal power control torque coefficient. The input of q-axis current control target value calculation 11-2 is the motor control target torque T*, and the output is the generator q-axis current control target value i sq * , the formula is as follows:

[0080]

[0081] Where n p is the number of generator pole pairs, Ψ f is the permanent magnet flux of the generator.

[0082] The current inner loop calculation module 12 includes PI calculations 12-1 and 12-2, dq coordinate transformation 12-3 and dq coordinate inverse transformation 12-4. First, the three-phase current measurement value i of the generator is sabc Converted into dq axis current i through dq transformation sdq ,as follows:

[0083]

[0084] Then, the voltage value corresponding to the current loop is calculated by PI, the formula is as follows:

[0085]

[0086] Afterwards, the dq axis cross-influence term is introduced to obtain the target value of the generator stator dq axis voltage control, and the formula is as follows:

[0087]

[0088] In the formula, ω e is the electromagnetic speed of the generator rotor, which is ω g and n p Finally, the generator stator dq axis voltage control target value u sdq * Substitute the dq coordinate inverse transformation to calculate the converter side converter modulation voltage control target value u sabc * , the formula is as follows:

[0089]

[0090] Each DC side energy storage device tracks the target power through the DC-DC bidirectional converter 4-2 See also Figure 4 The energy storage DC-DC converter control module mainly includes 20-charging control process and 21-discharging control process. 20-charging control process mainly consists of S1 controlling the conversion switch 20-1, charging modulation voltage PI calculation 20-2, and charging reference current calculation 20-3. 21-discharging control process mainly consists of S2 controlling the conversion switch 21-1, discharging modulation voltage PI calculation 21-2, and discharging reference current calculation 21-3.

[0091] When the energy storage device is charging, S1 controls the conversion switch to switch to the charging controller, and S2 controls the conversion switch to switch off. The DC-DC charges the energy storage battery through the step-down conversion mode. First, the charging reference current is calculated by the charging reference power, and the formula is as follows:

[0092]

[0093] Then, by substituting the charging reference current and the measured charging current into the PI module, the charging modulation voltage is calculated as follows:

[0094]

[0095] Finally, the IGBT module T1 is controlled to be switched on and off at a certain duty cycle through the charge modulation voltage, so that the energy storage device can be charged according to the specified reference power.

[0096] When the energy storage device is discharging, S1 controls the conversion switch to switch off, and S2 controls the conversion switch to switch to the discharge controller. The DC-DC discharges the energy storage battery through the boost conversion mode. First, the charging reference current is calculated by the charging reference power, and the formula is as follows:

[0097]

[0098] Then, the discharge reference current and the measured discharge current are substituted into the PI module to calculate the discharge modulation voltage as follows:

[0099]

[0100] Finally, the IGBT module T2 is controlled to be switched on and off at a certain duty cycle through the discharge modulation voltage, so that the energy storage device can be discharged according to the specified reference current.

[0101] The grid-side converter of each wind turbine generator set stabilizes the DC bus voltage through current loop control, thereby Real-time power delivery to the grid ( is the actual output power of the wind turbine, is the discharge power of the energy storage device), see Figure 5 The converter control module at the grid side of the converter mainly includes a phase-locked loop phase angle calculation module 30 , a current outer loop calculation module 31 and a current inner loop calculation module 32 .

[0102] The input of the phase-locked loop phase angle calculation module 30 is the three-phase voltage measured by the power grid, and the output is the power grid frequency and phase angle. The calculation process is shown in Figure 6 First, set the initial phase to θ, substitute it into the dq coordinate transformation, and calculate the grid voltage u od and u oq The value is as follows:

[0103]

[0104] will u oq Substitute into the PI formula to calculate the grid frequency. The formula is as follows:

[0105]

[0106] Integrate ω to calculate the grid phase angle, the formula is as follows:

[0107]

[0108] If u oq If it is not close to 0, substitute the calculated phase angle into equations (18) to (20) to recalculate the grid frequency and phase angle until u oq Close to 0, locking the grid frequency and phase angle.

[0109] The current outer loop calculation module 31 includes a d-axis current outer loop PI calculation 31-1 and a q-axis current outer loop PI calculation 31-2. The d-axis current outer loop PI calculation 31-1 inputs the converter DC bus capacitance measurement value U DC and reference value Output is the d-axis current control target value The calculation formula is as follows:

[0110]

[0111] The input of the q-axis current outer loop PI calculation 31-2 is the reactive power measurement value Q i and reference value Output is the q-axis current control target value The calculation formula is as follows:

[0112]

[0113] The current inner loop calculation module 32 includes PI calculations 32-1 and 32-2, dq coordinate transformation 32-3 and dq coordinate inverse transformation 32-4. First, the inverter output three-phase current measurement value i abc Converted into dq axis current i through dq transformation dq Then, the voltage value corresponding to the current loop is calculated by PI, and the formula is as follows:

[0114]

[0115] Afterwards, the inverter dq axis voltage control target value is obtained by introducing the dq axis cross-influence term, and the formula is as follows:

[0116]

[0117] Finally, the inverter dq axis voltage control target value u dq * Substitute the dq coordinate inverse transformation to calculate the inverter modulation voltage control target value u abc * , the formula is as follows:

[0118]

[0119] By implementing the disclosed embodiment, the charge and discharge control of the energy storage device is performed based on the deviation between the smoothed output reference power value and the actual output power of the wind turbine, and the state of charge of the energy storage device is considered, thereby greatly improving the stability of wind power output, reducing harmonic content, and making it closer to transmission energy. Wind power with unstable output can better participate in the dispatching arrangement of the power grid, improve the competitiveness of wind farms in the power market, and promote large-scale grid connection and consumption of wind power.

[0120] In order to further improve the effect of smoothing the wind power output power of the wind power generation system, in some embodiments of the present disclosure, the smoothed output reference power value of the wind turbine group in the next control time period can be determined based on the comparison result of the deviation value in the current control time period with the maximum discharge power and the maximum charging power, and the smoothed output reference power value of the current control time period.

[0121] When the deviation value is greater than or equal to the maximum charging power and less than or equal to the maximum discharging power The smoothed output reference power value remains unchanged, and the smoothed output reference power value of the current control time period is determined as the smoothed output reference power value of the wind turbine in the next control time period.

[0122] When the charge state of the energy storage device is too low or too high, the smoothed power output reference value is adjusted according to the charge state of the energy storage device in the current control time period to obtain the smoothed output reference power value of the wind turbine set in the next control time period.

[0123] When the deviation value is greater than the maximum discharge power The smoothed output reference power reduction conversion coefficient is determined according to the state of charge, and the smoothed output reference power value of the wind turbine in the next control time period is determined according to the smoothed output reference power reduction conversion coefficient and the smoothed output reference power value.

[0124] The smoothed output reference power drop conversion coefficient is determined by the following formula:

[0125]

[0126] Where k1(j) is the smooth output reference power down conversion coefficient, SOC B,i is the state of charge, k0 is the basic coefficient of smooth output reference power conversion.

[0127] The smoothed output reference power value of the next control time period is determined by the following formula:

[0128]

[0129] in, is the smoothed output reference power value of the wind turbine in the next control time period, To smooth the output reference power value, ΔT is the control period step.

[0130] When the deviation value is less than the maximum charging power The smooth output reference power increase conversion coefficient is determined according to the state of charge, and the smooth output reference power value of the wind turbine in the next control time period is determined according to the smooth output reference power increase conversion coefficient and the smooth output reference power value.

[0131] Among them, the smooth output reference power rise conversion coefficient is determined by the following formula:

[0132]

[0133] Where k2(j) is the smooth output reference power rise conversion coefficient, SOC B,i is the state of charge, k0 is the basic coefficient of smooth output reference power conversion.

[0134] The smoothed output reference power value is determined by the following formula:

[0135]

[0136] in, is the smoothed output reference power value of the wind turbine in the next control time period, To smooth the output reference power value, ΔT is the control period step.

[0137] This embodiment can determine the smooth output reference power value of the wind turbine in the next control time period according to the comparison result. When the state of charge of the energy storage device is too low or too high, the smooth power output reference value is adjusted according to the state of charge of the energy storage device in the current control time period to obtain the smooth output reference power value of the wind turbine in the next control time period, so that the energy storage device is maintained at the optimal state of charge.

[0138] Figure 7 Schematic diagram of a control device for a wind power generation system provided by an embodiment of the present disclosure. Figure 1 The embodiment shown. Figure 7 As shown, the control device of the wind power generation system may include:

[0139] The acquisition module 701 is used to acquire the average output power of the wind turbine generator set in a previous preset control time period, and determine the average output power as the smoothed output reference power value of the wind turbine generator set in the current control time period.

[0140] The first determination module 702 is used to determine the maximum discharge power and the maximum charge power of the energy storage device in the current control time period based on the charge state of the battery unit.

[0141] The second determination module 703 is used to determine the deviation value between the smoothed output reference power value and the actual output power of the wind turbine generator set in the current control time period.

[0142] The third determination module 704 is used to compare the deviation value with the maximum discharge power and the maximum charge power, and determine the charge and discharge target power of the energy storage device based on the comparison result.

[0143] The control module 705 is used to control the charging and discharging of the energy storage device according to the charging and discharging target power.

[0144] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0145] In order to implement the above embodiments, the present disclosure also proposes an electronic device, including: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method provided by the above embodiments.

[0146] In order to implement the above embodiments, the present disclosure further proposes a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the methods provided by the above embodiments.

[0147] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0148] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0149] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present disclosure includes additional implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present disclosure belong.

[0150] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0151] It should be understood that the various parts of the present disclosure can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used to implement: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0152] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0153] In addition, each functional unit in each embodiment of the present disclosure may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0154] The storage medium mentioned above may be a read-only memory, a disk or an optical disk, etc. Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present disclosure. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present disclosure.

Claims

1. A control method for a wind power generation system, characterized in that: The wind power generation system comprises: a wind turbine, a converter, a box-type transformer and an energy storage device, wherein the energy storage device comprises a battery unit, the wind turbine, the converter and the box-type transformer are connected in sequence, and the energy storage device is connected in parallel to the DC bus side of the converter; the method comprises the following steps: Acquire the average output power of the wind turbine generator set in a previous preset control time period, and determine the average output power as a smoothed output reference power value of the wind turbine generator set in a current control time period; Determining the maximum discharge power and the maximum charge power of the energy storage device in the current control time period based on the state of charge of the battery unit; Determine a deviation value between the smoothed output reference power value and the actual output power of the wind turbine generator set during the current control time period; Comparing the deviation value with the maximum discharge power and the maximum charge power, and determining the charge and discharge target power of the energy storage device based on the comparison result; The energy storage device is controlled to be charged and discharged according to the charge and discharge target power.

2. The method according to claim 1, characterized in that The determining the maximum discharge power and the maximum charge power of the energy storage device in the current control time period based on the state of charge of the battery unit includes: Determining a discharge coefficient and a charge coefficient of the energy storage device according to the state of charge of the battery unit; Determine the maximum discharge power according to the discharge coefficient and the rated charge and discharge power of the energy storage; The maximum charging power is determined according to the charging coefficient and the energy storage rated charging and discharging power.

3. The method according to claim 1, characterized in that The method of comparing the deviation value with the maximum discharge power and the maximum charge power, and determining the charge and discharge target power of the energy storage device based on the comparison result, comprises: In response to the deviation value being greater than or equal to the maximum charging power and less than or equal to the maximum discharging power, determining the deviation value as the charging and discharging target power; Alternatively, in response to the deviation value being greater than the maximum discharge power, determining the maximum discharge power as the charge and discharge target power; Alternatively, in response to the deviation value being smaller than the maximum charging power, the maximum charging power is determined as the charging and discharging target power.

4. The method according to any one of claims 1 to 3, characterized in that: Also includes: Based on the comparison result and the smoothed output reference power value, a smoothed output reference power value of the wind turbine generator set in the next control time period is determined.

5. The method according to claim 4, characterized in that The step of determining the smoothed output reference power value of the wind turbine generator set in the next control time period based on the comparison result includes: In response to the deviation value being greater than or equal to the maximum charging power and less than or equal to the maximum discharging power, determining the smoothed output reference power value as the smoothed output reference power value of the wind turbine generator set in the next control time period; Alternatively, in response to the deviation value being greater than the maximum discharge power, a smoothed output reference power drop conversion coefficient is determined according to the state of charge, and a smoothed output reference power value of the wind turbine in the next control time period is determined according to the smoothed output reference power drop conversion coefficient and the smoothed output reference power value; Alternatively, in response to the deviation value being less than the maximum charging power, a smoothed output reference power increase transformation coefficient is determined according to the charge state, and a smoothed output reference power value of the wind turbine group in the next control time period is determined according to the smoothed output reference power increase transformation coefficient and the smoothed output reference power value.

6. The method according to claim 5, characterized in that In response to the deviation value being greater than the maximum discharge power, the smoothed output reference power reduction conversion coefficient is determined by the following formula: Wherein, k1(j) is the smoothed output reference power down conversion coefficient, SOC B,i is the state of charge, k0 is the basic coefficient of smooth output reference power conversion; The smoothed output reference power value is determined by the following formula: in, is the smoothed output reference power value of the wind turbine generator set in the next control time period, is the smoothed output reference power value, and ΔT is the control period step.

7. The method according to claim 5, characterized in that In response to the deviation value being less than the maximum charging power, the smoothed output reference power increase conversion coefficient is determined by the following formula: Wherein, k2(j) is the smooth output reference power increase conversion coefficient, SOC B,i is the state of charge, k0 is the basic coefficient of smooth output reference power conversion; The smoothed output reference power value is determined by the following formula: in, is the smoothed output reference power value of the wind turbine generator set in the next control time period, is the smoothed output reference power value, and ΔT is the control period step.

8. A control device for a wind power generation system, characterized in that: The wind power generation system comprises: a wind turbine, a converter, a box-type transformer and an energy storage device, wherein the energy storage device comprises a battery unit, the wind turbine, the converter and the box-type transformer are connected in sequence, and the energy storage device is connected in parallel to the DC bus side of the converter; the device comprises: An acquisition module, used for acquiring the average output power of the wind turbine set in a previous preset control time period, and determining the average output power as a smoothed output reference power value of the wind turbine set in a current control time period; A first determination module, configured to determine a maximum discharge power and a maximum charge power of the energy storage device in the current control time period based on the state of charge of the battery unit; A second determination module is used to determine a deviation value between the smoothed output reference power value and the actual output power of the wind turbine generator set in the current control time period; A third determination module, configured to compare the deviation value with the maximum discharge power and the maximum charge power, and determine a charge and discharge target power of the energy storage device based on the comparison result; A control module is used to control the charging and discharging of the energy storage device according to the charging and discharging target power.

9. A wind power generation system, characterized in that: include: A wind turbine, a converter, a box-type transformer and an energy storage device, wherein the energy storage device comprises a battery unit; The wind turbine set, the converter and the box-type transformer are connected in sequence, and the energy storage device is connected in parallel to the DC bus side of the converter.

10. An electronic device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 7.

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