A power control method, apparatus and system

Abstract

The application discloses a power control method, device and system, the method comprises the following steps: receiving the active scheduling instruction issued by the dispatching department; determining the single-machine power instruction of each wind turbine according to the active scheduling instruction; each wind turbine executes the corresponding single-machine power instruction, and monitors the output port voltage of each wind turbine in real time; comparing the output port voltage of each wind turbine with the preset voltage limit value; when the comparison result exists the target wind turbine whose output port voltage exceeds the preset voltage limit value, the single-machine amplitude limiting control is carried out on the target wind turbine; the above-mentioned voltage monitoring, comparison and single-machine amplitude limiting control operation are circularly executed until the output voltage of all wind turbines is controlled in the safety range. The scheme can guarantee the power balance and voltage balance when multiple direct-current wind turbines operate.

Description

Technical Field

[0001] This application relates to the field of wind power generation technology, and in particular to a power control method, device and system. Background Technology

[0002] Currently, wind farms mainly adopt a power transmission mode based on AC power grids. As the scale of wind farms expands and their geographical distribution becomes increasingly dispersed, traditional AC power collection systems are gradually revealing their inherent drawbacks: limited transmission distance, high line losses, the need to configure a large number of reactive power compensation devices, and voltage and frequency fluctuations in the AC system caused by the output fluctuations of wind turbines, which can even easily lead to system oscillations during large-scale grid connection.

[0003] DC transmission boasts advantages such as high transmission efficiency, long transmission distance, and strong scalability, making it better suited to the development needs of new power systems dominated by new energy sources. Therefore, developing DC transmission technology within wind farms has become an ideal choice and a key technological direction for future ultra-large-scale wind farms. However, DC-type wind farms experience voltage imbalances on the DC side due to differences in wind speed and operating conditions among individual wind turbines during operation.

[0004] Developing a power control method to solve the power balance and voltage equalization problem when multiple DC wind turbines are operating has become an urgent technical issue. Summary of the Invention

[0005] This application provides a power control method, apparatus, and system to ensure power balance and voltage equalization during the operation of multiple DC wind turbine units.

[0006] This application provides a power control method, including: Receive active power dispatch instructions from the dispatching department; The single-unit power command of each wind turbine is determined according to the active power dispatch command. Each wind turbine executes its corresponding single-unit power command and monitors the output port voltage of each wind turbine in real time; Compare the output port voltage of each wind turbine with the preset voltage limit; When the comparison results show that the output port voltage of a target wind turbine exceeds the preset voltage limit, single-unit limiting control is performed on the target wind turbine. Repeat the above voltage monitoring, comparison, and single-unit limiting control operations until the output voltage of all wind turbine units is controlled within a safe range.

[0007] The beneficial effects of this application are as follows: Based on the active power dispatch instructions issued by the receiving dispatch department, the single-unit power instructions for each wind turbine are determined. Each wind turbine executes the corresponding single-unit power instructions, and the output port voltage of each wind turbine is monitored in real time. The output port voltage of each wind turbine is compared with a preset voltage limit. When a target wind turbine with an output port voltage exceeding the preset voltage limit is found in the comparison results, single-unit voltage limiting control is applied to the target wind turbine. This voltage monitoring, comparison, and single-unit voltage limiting control operation is repeated until the output terminal voltage of all wind turbines is controlled within a safe range. Because single-unit voltage limiting control is applied when a wind turbine exceeds the preset voltage limit, the problem of inconsistent DC-side voltage caused by wind speed differences and different equipment states is effectively solved. Simultaneously, power is redistributed, resulting in power balance throughout the wind farm, ensuring the stability of the DC-side voltage of the entire wind farm, and guaranteeing power balance and voltage equilibrium during the operation of multiple DC wind turbines.

[0008] In one embodiment, determining the individual power command of each wind turbine based on the active power dispatch command includes: The power adjustment command is determined based on the active power dispatch command and the real-time power of the wind power system. The power adjustment command is used to determine the individual power command of each wind turbine.

[0009] In one embodiment, determining the power adjustment command based on the active power dispatch command and the real-time power of the wind power system includes: Calculate the power deviation between the active power dispatch command and the real-time power; When the power deviation value is within the preset control range, the current power output is maintained and no power adjustment is performed. When the power deviation value exceeds the preset control range, a power adjustment command is determined based on the direction of the deviation.

[0010] In one embodiment, determining the power adjustment command based on the deviation direction includes: When the active power dispatch command is lower than the real-time power, the power adjustment command is determined to be a power reduction command; When the active power dispatch command is higher than the real-time power, the power adjustment command is determined to be a power increase command.

[0011] In one embodiment, the method further includes: When it is determined that the power adjustment command is to reduce power, the power adjustment command is issued according to the active power dispatch command.

[0012] In one embodiment, the method further includes: When the power adjustment command is determined to be an increase in power, the available power of each wind turbine is obtained; The total available power of the wind power system is determined based on the available power of each wind turbine unit. When the total available power is less than the power increase requirement of the dispatch, a power adjustment command is issued based on the maximum available power. If the total available power exceeds the power increase requirement of the dispatch, a power adjustment command will be issued according to the active power dispatch command.

[0013] In one embodiment, determining the individual power command of each wind turbine unit through the power regulation command includes: Based on the electrical topology of the DC wind power system, the corresponding power allocation rules are determined, wherein the electrical topology includes parallel topology, series topology and series-parallel hybrid topology; The power adjustment command is allocated to each wind turbine according to the corresponding power allocation rule to obtain the single-unit power command of each wind turbine.

[0014] In one embodiment, when the wind power system is a parallel topology subsystem, the power allocation rule is as follows: The power adjustment commands are distributed proportionally according to the output port voltage of each wind turbine. The power command for each wind turbine is determined based on the allocation results.

[0015] In one embodiment, the single-unit limiting control of the target wind turbine includes: When the output port voltage of the target wind turbine is greater than the preset voltage limit, but the rotor speed does not exceed the preset speed threshold, the pitch mechanism of the target wind turbine is controlled to perform a pitch retraction action. When the output port voltage of the target wind turbine is greater than the preset voltage limit and the rotor speed exceeds the preset speed threshold, the pitch control mechanism of the target wind turbine is controlled to perform a pitch retraction action and the wind turbine-side converter is controlled to limit the output power.

[0016] In one embodiment, the method further includes: While performing single-unit limiting control on the target wind turbine, the power of the target wind turbine is redistributed to other wind turbines that have not exceeded the preset voltage limit.

[0017] In one embodiment, the redistribution of the restricted power of the target wind turbine to other wind turbines that do not exceed a preset voltage limit includes: Calculate the voltage deviation between the output port voltage and the rated voltage of other wind turbine units that do not exceed the preset voltage limit, and the power deviation between the output power and the rated power. The total power deviation of the entire field is calculated based on the power deviation of the target wind turbine from that of other wind turbines that do not exceed the preset voltage limit. The total power deviation of the entire field is allocated based on the voltage deviation of other wind turbine units that do not exceed the preset voltage limit, and corresponding power correction instructions are generated. According to the power correction command, the power of other wind turbines that have not exceeded the preset voltage limit is adjusted to redistribute the restricted power of the target wind turbine.

[0018] This application also provides a power control device, including: The receiving module is used to receive active power dispatch instructions issued by the dispatching department; The determination module is used to determine the single-unit power command of each wind turbine according to the active power dispatch command; The monitoring module is used to execute the corresponding single-unit power command for each wind turbine and monitor the output port voltage of each wind turbine in real time. The comparison module is used to compare the output port voltage of each wind turbine with the preset voltage limit. The control module is used to perform single-unit limiting control on the target wind turbine when the output port voltage of the target wind turbine exceeds the preset voltage limit in the comparison result. The loop module is used to repeatedly perform the above voltage monitoring, comparison and single-unit limiting control operations until the output voltage of all wind turbine units is controlled within a safe range.

[0019] In one embodiment, the determining module includes: The first determining submodule is used to determine the power adjustment command based on the active power dispatch command and the real-time power of the wind power system; The second determining submodule is used to determine the single-unit power command of each wind turbine through the power adjustment command.

[0020] In one embodiment, the first determining submodule is further configured to: Calculate the power deviation between the active power dispatch command and the real-time power; When the power deviation value is within the preset control range, the current power output is maintained and no power adjustment is performed. When the power deviation value exceeds the preset control range, a power adjustment command is determined based on the direction of the deviation.

[0021] In one embodiment, determining the power adjustment command based on the deviation direction includes: When the active power dispatch command is lower than the real-time power, the power adjustment command is determined to be a power reduction command; When the active power dispatch command is higher than the real-time power, the power adjustment command is determined to be a power increase command.

[0022] In one embodiment, the first determining submodule is further configured to: When it is determined that the power adjustment command is to reduce power, the power adjustment command is issued according to the active power dispatch command.

[0023] In one embodiment, the first determining submodule is further configured to: When the power adjustment command is determined to be an increase in power, the available power of each wind turbine is obtained; The total available power of the wind power system is determined based on the available power of each wind turbine unit. When the total available power is less than the power increase requirement of the dispatch, a power adjustment command is issued based on the maximum available power. If the total available power exceeds the power increase requirement of the dispatch, a power adjustment command will be issued according to the active power dispatch command.

[0024] In one embodiment, the second determining submodule is further configured to: Based on the electrical topology of the DC wind power system, the corresponding power allocation rules are determined, wherein the electrical topology includes parallel topology, series topology and series-parallel hybrid topology; The power adjustment command is allocated to each wind turbine according to the corresponding power allocation rule to obtain the single-unit power command of each wind turbine.

[0025] In one embodiment, when the wind power system is a parallel topology subsystem, the power allocation rule is as follows: The power adjustment commands are distributed proportionally according to the output port voltage of each wind turbine. The power command for each wind turbine is determined based on the allocation results.

[0026] In one embodiment, the control module further includes: The first control submodule is used to control the pitch mechanism of the target wind turbine to perform a pitch-retracting action when the output port voltage of the target wind turbine is greater than a preset voltage limit, but the rotor speed does not exceed a preset speed threshold. The second control submodule is used to control the pitch mechanism of the target wind turbine to perform a pitch-retracting action and control the wind turbine-side converter to limit the output power when the output port voltage of the target wind turbine is greater than the preset voltage limit and the rotor speed exceeds the preset speed threshold.

[0027] In one embodiment, the apparatus further includes: The allocation module is used to redistribute the restricted power of the target wind turbine to other wind turbines that have not exceeded the preset voltage limit while performing single-unit limiting control on the target wind turbine.

[0028] In one embodiment, the allocation module includes: The first calculation submodule is used to calculate the voltage deviation between the output port voltage and the rated voltage of other wind turbine units that do not exceed the preset voltage limit, as well as the power deviation between the output power and the rated power. The second calculation submodule is used to calculate the total power deviation of the entire field based on the power deviation of the target wind turbine unit from that of other wind turbine units that have not exceeded the preset voltage limit. The generation submodule is used to allocate the total power deviation of the entire field according to the voltage deviation of other wind turbine units that have not exceeded the preset voltage limit, and generate corresponding power correction instructions. The adjustment submodule is used to adjust the power of other wind turbines that have not exceeded the preset voltage limit according to the power correction command, so as to realize the redistribution of the restricted power of the target wind turbine.

[0029] This application also provides a power control system, including: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to implement the power control method described in any of the above embodiments.

[0030] This application also provides a computer-readable storage medium that, when the instructions in the storage medium are executed by a processor corresponding to the power control system, enables the power control system to implement the power control method described in any of the above embodiments.

[0031] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0032] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0033] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the embodiments of the present application to explain the application and do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a power control method according to an embodiment of this application; Figure 2 This is a control flowchart of a wind farm DC transmission system according to an embodiment of this application; Figure 3 This is a schematic diagram of the star topology of a wind farm DC transmission system in one embodiment of this application; Figure 4 This is a schematic diagram of the radial topology of a wind farm DC transmission system in one embodiment of this application; Figure 5 This is a schematic diagram of a ring network topology of a wind farm DC transmission system in one embodiment of this application; Figure 6 This is a schematic diagram of the structure of a power control device according to an embodiment of this application; Figure 7 This is a schematic diagram of the hardware structure of a power control system according to one embodiment of this application. Detailed Implementation

[0034] The preferred embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0035] To address the issue of DC-side voltage imbalance caused by differences in wind speed and operating status among wind turbines in DC-type wind farms, unified control is required to achieve power balance and system stability when multiple wind turbines are connected to a DC power collection system.

[0036] Figure 1 This is a flowchart of a power control method according to an embodiment of this application, such as... Figure 1 As shown, the method can be implemented as follows: S101-S106: In step S101, the active power dispatch instruction issued by the dispatching department is received; In step S102, the single-unit power command of each wind turbine is determined according to the active power dispatch command; In step S103, each wind turbine executes the corresponding single-unit power command and monitors the output port voltage of each wind turbine in real time; In step S104, the output port voltage of each wind turbine is compared with a preset voltage limit. In step S105, when there is a target wind turbine whose output port voltage exceeds the preset voltage limit in the comparison result, single-unit limiting control is performed on the target wind turbine. In step S106, the above voltage monitoring, comparison and single-unit limiting control operations are performed cyclically until the output voltage of all wind turbine units is controlled within a safe range.

[0037] In this application, active power dispatch instructions are received from the dispatching department. The power dispatch instruction is the total power requirement issued by the power grid for the entire wind power system; it is a global instruction. This application primarily acquires active power dispatch instructions. This is because in a DC system, voltage stability depends entirely on the real-time balance of active power. Therefore, by acquiring the active power dispatch instructions issued by the power grid and distributing the active power output of each unit through internal voltage balancing control, the DC bus voltage can be maintained stably. Reactive power regulation is mainly used to support the AC grid voltage. In a wind farm DC transmission system, this coordination is usually completed uniformly by the grid-connected converter station (or STATCOM, etc.) at the wind farm's outlet, without the need to separately acquire and distribute reactive power instructions in the control strategy of the on-site DC aggregation.

[0038] The individual power command for each wind turbine is determined based on the active power dispatch command. Specifically, the power adjustment command is first determined based on the active power dispatch command and the real-time power of the wind power system, and then the individual power command for each wind turbine is determined based on the power adjustment command.

[0039] Because the power demand of the power grid fluctuates in real time with the electricity load, the active power dispatch command is the power requirement of the power grid for the wind power system at a specific time period. However, the real-time power of the wind power system is affected by factors such as wind speed and unit status, and there will inevitably be a dynamic deviation between the two. Only by comparing them can the deviation be detected and adjusted in a timely manner. By comparing the active power dispatch command (the power demand of the power grid for the wind power system) with the real-time power of the wind power system (the current actual output power of the wind power system), the power deviation value between the active power dispatch command and the real-time power can be calculated, and the deviation between the current power supply and demand can be clearly identified. When the power deviation value is within the preset control range, the current power output is maintained, and no power adjustment is performed; otherwise, when the power deviation value exceeds the preset control range, a power adjustment command is determined according to the direction of the deviation.

[0040] If the active power dispatch command is lower than the real-time power, the power adjustment command is determined to be a power reduction command, and a power adjustment command is issued according to the active power dispatch command. If the active power dispatch command is higher than the real-time power, the power adjustment command is determined to be a power increase command. In this case, to ensure the safe and stable operation of the unit, avoid equipment overload, and maximize the exploitation of wind energy potential, the issuance of the power adjustment command must consider the actual available power of the unit. Available power must include at least the energy from both pitch control and turbine-side control in the single-unit limiting control. Otherwise, if the command is not issued in conjunction with the energy situation of pitch control and turbine-side control, the unit terminal voltage may exceed the limiting range, triggering the protection mechanism and preventing the power increase operation from being completed. Therefore, when the power adjustment command is determined to be a power increase, the available power of each wind turbine is obtained; the total available power of the wind power system is determined based on the available power of each wind turbine; the total available power is compared with the dispatch power increase requirement; when the total available power is less than the dispatch power increase requirement, a power adjustment command is issued according to the maximum available power to avoid turbine overload; if the total available power is greater than the dispatch power increase requirement, a power adjustment command is issued according to the active power dispatch command to meet the power demand of the power grid as much as possible.

[0041] When determining the individual power command of each wind turbine through the power regulation command, a corresponding power allocation rule can be determined based on the electrical topology of the DC wind power system. The power regulation command is then allocated to each wind turbine according to this rule, resulting in the individual power command for each turbine. For example, when the wind power system is a parallel topology subsystem, the power allocation rule is as follows: the power regulation command is allocated proportionally based on the output port voltage of each wind turbine; the individual power command for each wind turbine is determined based on the allocation result. When the wind power system is a series topology subsystem, the power allocation rule is as follows: the power dispatch command is allocated to each turbine based on the total voltage of the series-connected turbines, the characteristics of the shared current path, and the maximum output capacity of each turbine. Differences in the port voltages of each turbine are allowed, but must be controlled within a safe range, and the total current of the series link must be kept stable. When the wind power system is a series-parallel hybrid topology subsystem, the power allocation rule is as follows: the system is divided into multiple series cluster sub-units, and each series cluster sub-unit is connected in parallel; firstly, power is allocated for each series cluster sub-unit according to the series topology power allocation rule, and then the power demand of each series cluster sub-unit is allocated as a whole according to the parallel topology power allocation rule.

[0042] Each wind turbine executes its corresponding single-unit power command and monitors the output port voltage of each wind turbine in real time. The output port voltage of each wind turbine is compared with a preset voltage limit. When a target wind turbine is found whose output port voltage exceeds the preset voltage limit, single-unit voltage limiting control is applied to the target wind turbine, and the restricted power is redistributed to other wind turbines that have not exceeded the preset voltage limit. The above voltage monitoring, comparison, and single-unit voltage limiting control operations are repeated until the output port voltage of all wind turbines is controlled within a safe range.

[0043] In one embodiment, when performing single-unit limiting control, the pitch mechanism of the target wind turbine is controlled to perform a pitch-down action and / or the wind turbine-side converter is controlled to limit the output power, so that the output port voltage of the target wind turbine falls back to within a preset voltage limit range. Specifically, the output port voltage of the target wind turbine is compared with the preset voltage limit to determine the deviation value exceeding the limit, the power value to be limited (output limiting value) is calculated, and converted into specific pitch and / or converter control commands. The specific calculation process can be calibrated through prior experiments to determine the correspondence between the deviation value and the output limiting value, as well as the correspondence between the output limiting value and the pitch and / or converter control commands. This application will not elaborate further on this.

[0044] In another embodiment, when performing single-unit limiting control, the control can also be combined with the rotor speed of the target wind turbine. When the output port voltage of the target wind turbine is greater than a preset voltage limit, but the rotor speed does not exceed a preset speed threshold, the pitch mechanism of the target wind turbine is controlled to perform a pitch retraction action; when the output port voltage of the target wind turbine is greater than the preset voltage limit and the rotor speed exceeds the preset speed threshold, the pitch mechanism of the target wind turbine is controlled to perform a pitch retraction action, and the wind turbine-side converter is controlled to limit the output power.

[0045] When multiple DC wind turbines are connected in series and parallel, since the total DC bus voltage remains constant, the DC voltage amplitude of each wind turbine connected in series below the DC bus is determined by the proportion of each turbine's output power to the total output power; an increase in the output power of a single wind turbine will lead to a decrease in the DC side voltage of other wind turbines.

[0046] Specifically, during the single-unit limiting control process, the port voltage of the unit can be reduced to a safe range by adjusting the pitch angle and / or the control parameters of the generator-side converter.

[0047] When the wind power system is a parallel topology subsystem, if there is a target wind turbine with an output port voltage exceeding the preset voltage limit, only the turbine with the output port voltage exceeding the limit will be activated for single-unit limiting control. The remaining turbines will maintain their current output status, and the remaining power will be directly distributed to the turbines that have not exceeded the limit. There is no need to adjust the operating parameters of the turbines that have not exceeded the limit.

[0048] When the wind power system is a series topology subsystem, if there is a target wind turbine with an output port voltage exceeding the preset voltage limit, the DC / DC unit coordinates the operation of the over-limit and non-over-limit turbines: the DC / DC unit absorbs the excess voltage energy of the over-limit turbines, maintains the power output of the non-over-limit turbines, and at the same time recalculates the total power demand of the series cluster, dynamically adjusts the output parameters of the DC / DC unit, and realizes continuous power transmission of the system.

[0049] When the wind power system is a series-parallel hybrid topology subsystem, if there is a target wind turbine in a series cluster sub-unit whose output port voltage exceeds the preset voltage limit, it is first processed in the series cluster sub-unit according to the single-unit limiting control and power regulation method of the series topology. Then, based on the overall power output of the series cluster sub-unit after processing, the power distribution between each series cluster sub-unit is readjusted to ensure the overall power balance and voltage stability of the system.

[0050] When the output limiting control is activated, the restricted power is redistributed to other wind turbines that have not exceeded the preset voltage limit.

[0051] Specifically, by monitoring the output port voltage and output power of other units, and calculating the voltage deviation between the output port voltage and the rated voltage of other units, as well as the power deviation between the output power and the rated power of other units; based on the voltage deviation and power deviation, power correction commands corresponding to other units are generated. For example, the total power deviation of the entire field is calculated based on the power limitation of the target wind turbine and the power deviation of other units, and the total power deviation of the entire field is allocated based on the voltage deviation of other units to generate corresponding power correction commands.

[0052] When generating the corresponding power correction command, the total power deviation of the entire field can be allocated according to the proportion of the voltage deviation of other units. The allocation weight for each wind turbine is calculated as the proportion of the voltage deviation of each other unit to the total voltage deviation of all other units. This voltage deviation includes both positive and negative deviations. Multiplying the allocation weight of each other unit by the total power deviation of the entire field yields the corresponding power adjustment amount for each other unit. The corresponding power correction command is then generated based on these power adjustment amounts. Alternatively, a table showing the correspondence between different voltage deviations and the proportion of total power adjustment can be set to determine the power adjustment value allocated to each wind turbine. Other units adjust their power according to the power correction command, while continuously monitoring the output port voltage and output power of each unit until both output port voltage and power of all units in the field stabilize within a preset range.

[0053] Understandably, when the restricted power exceeds the power deviation between the output power and rated power of other units, a corresponding power correction command is determined based on the rated power of each unit. The remaining unallocated power is temporarily stored and redistributed when subsequent voltage conditions are met. Each power receiving unit adjusts its output power according to the power correction command, while continuously monitoring its own output port voltage and output power. The adjustment ends when the output port voltages of all units in the field are stable within the preset range and there are no power allocation conflicts; if a new unit with excessive voltage is detected, the power allocation logic is retried.

[0054] Understandably, during the power regulation process, the deviation between the total system power and the scheduling command can be monitored in real time. When the deviation is less than a preset threshold, the adjustment range of power regulation can be reduced to avoid excessive fluctuations in system power.

[0055] In addition, when allocating power, historical operating data and wind speed forecast information of each wind turbine can be taken into account to pre-adjust the power allocation ratio, improve the accuracy and foresight of power allocation, and reduce voltage fluctuations caused by sudden changes in wind speed.

[0056] Figure 2 This is a control flowchart of a wind farm DC transmission system according to one embodiment of this application, as follows: Figure 2 As shown, when the output power of a wind turbine changes with wind speed in MPPT (Maximum Power Point Tracking) mode, the DC-side voltage of the turbine is dynamically redistributed according to its proportion of the total output power. However, during operation, DC-type wind farms experience variations in wind speed and operating conditions, leading to deviations in the DC-side voltage of each turbine, which is detrimental to the safe and stable operation of the wind farm. Therefore, voltage balancing control of DC-type wind farms needs to be considered from the perspective of the entire farm. This involves both limiting control of individual DC wind turbines and balancing control of the DC-side voltage of the entire wind farm. During voltage balancing control, the dispatching department's requirements are first executed. When the dispatching command exceeds the real-time power control threshold, the wind farm's output power is adjusted according to the dispatching command value. The issuance of power commands must consider the actual available power of the turbines, which includes energy from both pitch control and turbine-side control in individual turbine limiting control. The issued power commands are distributed to each unit according to the current port voltage of each unit and executed accordingly. The port voltage of each unit is then detected after execution. If the port voltage of any unit exceeds the limit voltage Uo*, the unit enters single-unit limiting control and redistributes the scheduling commands until the terminal voltage of all units stabilizes within an allowable range.

[0057] Through the closed-loop feedback control of "power distribution - voltage verification - single-unit limiting - redistribution" described above, the DC-side voltage of all wind turbines is ensured to operate stably within the allowable safe range, effectively solving the voltage balance problem of multiple turbines in parallel. This, in turn, enables the DC collection and efficient transmission of wind farm power, improving the operational stability of the wind farm and its support capability for new power systems.

[0058] This solution ensures that when multiple DC wind turbines are connected in series or in parallel to the same DC bus, the DC side port voltage of each turbine remains within an acceptable stable range, thus preventing voltage anomalies in other turbines due to power fluctuations in a single turbine and threatening system stability.

[0059] In one embodiment of this application, the main hardware implementation device includes the following components: a wind turbine generator, an AC / DC converter, a DC boost converter, a DC buck converter, a control unit, an energy management unit, a communication unit, and an AC boost converter.

[0060] Among them, wind turbine units are used for wind power generation, converting wind energy into electrical energy and outputting direct current; The AC / DC conversion unit is used for AC / DC conversion. On the wind turbine side, it rectifies the AC power generated by the wind turbine into DC power; at the grid connection point, it inverts the DC power into AC power and connects it to the power grid. DC boost unit is used to boost DC voltage to meet the requirements of long-distance, low-loss power transmission; A DC step-down unit is used to reduce DC voltage to meet the voltage level requirements of different equipment or line sections. An AC boost unit is used to increase the AC voltage so that it can be matched with the external high-voltage AC power grid.

[0061] The control unit is used to control the coordinated operation and stable functioning of all units. The energy management unit is used to receive and parse instructions and control requirements from the control unit, and execute corresponding energy scheduling strategies. Communication units are used for information exchange between various units, including CANopen communication units, TCP / IP communication units, and fiber optic communication units.

[0062] When applying the aforementioned control methods based on parallel, series, or hybrid electrical topologies, it is necessary to deploy them in conjunction with the actual DC transmission network architecture used in the wind farm. Depending on the actual conditions of the wind farm (such as turbine distribution, scale, reliability requirements, etc.), the DC transmission system of the wind farm can choose from various architecture forms. Several specific DC network architectures are analyzed below.

[0063] Figure 3This is a schematic diagram of a star topology architecture for a wind farm DC transmission system in one embodiment of this application. In a star topology, multiple wind turbines are directly connected to the substation via DC lines, offering strong independence and a small fault impact range, but requiring a large amount of cable. It is suitable for scenarios where wind turbines are distributed dispersedly. In this architecture analysis, it is assumed that each wind turbine (or wind turbine branch) is independently connected in parallel to the substation bus, forming a typical parallel electrical structure. Therefore, the power distribution and voltage balancing control strategies of the aforementioned parallel topology can be adopted. Based on the characteristic that each wind turbine branch in a star topology is independently connected to a booster station, power dispatch commands are distributed proportionally according to the output port voltage of each wind turbine. The port voltage and branch current of each wind turbine branch are monitored in real time. When the port voltage of a branch exceeds the preset safe voltage limit, single-unit limiting control is initiated only for the wind turbine corresponding to that branch, while the power distribution status of the remaining branches remains unchanged. After completing the single-unit limiting control, the output power of the branch is recalculated, and the difference between the grid dispatch command and the output power of the branch is redistributed according to the real-time port voltage ratio of the remaining branches until the port voltage of all wind turbine branches is stable within the allowable range.

[0064] Figure 4 This diagram illustrates a radial topology of a DC transmission system for a wind farm, as shown in one embodiment of this application. In a radial topology, multiple wind turbines (or turbine groups) are connected in series or parallel to a substation via a single DC line. This design is simple, low-cost, and suitable for small-scale onshore wind farms, but suffers from lower reliability (a single line failure affects multiple turbines). Under this architecture, multiple wind turbines can be connected in series or parallel on a single trunk line, forming series or parallel electrical subunits. The following analysis focuses on the most common scenario where wind turbines are connected in parallel on the trunk line, where power allocation must consider both line impedance and location weights. If series subunits exist, the allocation rules for series topologies should be used. In a radial topology, considering the impedance and capacity limitations of the main line, the maximum power that the main line can carry is first calculated. If the grid dispatch command exceeds the maximum power that the main line can carry, power allocation is prioritized according to the maximum power that the main line can carry. The power dispatch command is then comprehensively allocated according to the position weight of each wind turbine on the main line and the real-time output port voltage. The position weight is determined based on factors such as the distance between the wind turbine and the substation and the line impedance. The voltage drop of the main line and the port voltage of each wind turbine are monitored in real time. When the port voltage of a wind turbine exceeds the preset safe voltage limit, the single-unit limiting control of that wind turbine is activated, and the power allocation ratio of the remaining wind turbines on the main line is adjusted to compensate for the power loss caused by the limiting of that wind turbine and maintain the power stability of the main line. The operating status of the main line is continuously monitored. When a fault occurs in the main line, the power of the wind turbines downstream of the fault is quickly transferred to the backup line or the power output of the upstream wind turbines is adjusted to avoid large-scale wind turbine shutdowns.

[0065] Figure 5 This diagram illustrates a ring network topology of a wind farm DC transmission system according to one embodiment of this application. In this ring network topology, multiple wind turbines are connected to a booster station via a ring-shaped DC line, providing redundant paths and high reliability. The redundant path characteristic of the ring network architecture requires the control strategy to flexibly handle potential series or parallel electrical connections on different paths. During path planning and power optimization, the electrical topology of the wind turbines on each available path must be identified, and corresponding control logic must be applied. When a section of the ring network fails, current can continue to be transmitted through other paths, making it suitable for onshore or offshore wind farms with high reliability requirements. Leveraging the redundant path characteristics of a ring network topology, the power flow and voltage distribution of each line in the ring network are monitored in real time. Based on the power balance principle of the ring network, power dispatch commands are allocated to different paths in the ring network. When a fault occurs in a section of the ring network, the fault location is quickly identified, and the faulty line is isolated by switching the ring network's operating mode. Simultaneously, the power originally transmitted through the faulty line is transferred to other available paths in the ring network. During the power transfer process, the power allocation ratio of the wind turbines on each path is adjusted in real time. Based on the real-time output port voltage of each wind turbine and the impedance characteristics of the path, the power allocation is dynamically optimized to ensure voltage stability and power balance in the ring network. The operating status of the ring network is continuously monitored, and the redundant paths of the ring network are tested and maintained regularly. When the carrying capacity of a certain path decreases, the power allocation strategy is adjusted in advance to avoid faults.

[0066] Overall, this solution constructs a DC transmission network within the wind farm using DC wind turbine generators, DC transformer modules (boost / buck), and DC transmission modules. At the wind farm's output, the DC power is converted to AC power via an AC-DC converter system, and the voltage is boosted to a level matching the external power grid using an AC boost unit, ultimately enabling the safe and efficient transmission of wind power.

[0067] The control unit employs a multi-level hierarchical control scheme. The bottom layer controls the voltage / current of the wind turbine, while combining the wind turbine pitch system and converter power regulation function to smooth out power surges caused by wind speed fluctuations and avoid drastic DC voltage fluctuations. The upper layer optimizes the power distribution of the wind farm, realizing coordinated control of the wind turbine, wind farm, and power grid.

[0068] Based on the active power dispatch instructions issued by the dispatching department, the individual power instructions for each wind turbine are determined. Each wind turbine executes its corresponding individual power instruction, and the output port voltage of each wind turbine is monitored in real time. The output port voltage of each wind turbine is compared with a preset voltage limit. When a target wind turbine's output port voltage exceeds the preset voltage limit, single-unit voltage limiting control is applied to the target wind turbine, and the restricted power is redistributed to other wind turbines that do not exceed the preset voltage limit. This voltage monitoring, comparison, and single-unit voltage limiting control operation is repeated until the output port voltage of all wind turbines is controlled within a safe range. Because single-unit voltage limiting control is applied to wind turbines exceeding the preset voltage limit, the problem of inconsistent DC-side voltage caused by differences in wind speed and equipment status is effectively solved. Simultaneously, the power redistribution ensures power balance throughout the wind farm, guaranteeing the stability of the DC-side voltage and ensuring power and voltage balance during the operation of multiple DC wind turbines, thus ensuring the safe and efficient operation of the system.

[0069] In one embodiment, step S102 above can be implemented as steps A1-A2 as follows: In step A1, a power adjustment command is determined based on the active power dispatch command and the real-time power of the wind power system; In step A2, the individual power command of each wind turbine is determined by the power adjustment command.

[0070] In one embodiment, step A1 above can be implemented as steps A11-A13 as follows: In step A11, the power deviation between the active power dispatch command and the real-time power is calculated; In step A12, when the power deviation value is within the preset control range, the current power output is maintained and no power adjustment is performed; In step A13, when the power deviation value exceeds the preset control range, a power adjustment command is determined based on the deviation direction.

[0071] In one embodiment, step A13 above can be implemented as steps A131-A132: In step A131, when the active power dispatch command is lower than the real-time power, the power adjustment command is determined to be a power reduction command; In step A132, when the active power scheduling command is higher than the real-time power, the power adjustment command is determined to be a power increase command.

[0072] In one embodiment, the method may also be implemented as follows: When it is determined that the power adjustment command is to reduce power, the power adjustment command is issued according to the active power dispatch command.

[0073] In one embodiment, the method may also be implemented as steps B1-B4: In step B1, when it is determined that the power adjustment command is to increase the power, the available power of each wind turbine is obtained; In step B2, the total available power of the wind power system is determined based on the available power of each wind turbine. In step B3, when the total available power is less than the power increase requirement, a power adjustment command is issued based on the maximum available power. In step B4, if the total available power is greater than the power increase requirement of the dispatch, a power adjustment command is issued according to the active power dispatch command.

[0074] In one embodiment, step A2 above can be implemented as steps A21-A22: In step A21, the corresponding power allocation rules are determined according to the electrical topology of the DC wind power system, wherein the electrical topology includes parallel topology, series topology and series-parallel hybrid topology; In step A22, the power adjustment command is allocated to each wind turbine according to the corresponding power allocation rule to obtain the single-unit power command of each wind turbine.

[0075] In one embodiment, when the wind power system is a parallel topology subsystem, the power allocation rule is as follows: The power adjustment commands are distributed proportionally according to the output port voltage of each wind turbine; and the single-unit power command of each wind turbine is determined based on the distribution results.

[0076] In one embodiment, step S105 above can be implemented as steps C1-C2 as follows: In step C1, when the output port voltage of the target wind turbine is greater than the preset voltage limit, but the rotor speed does not exceed the preset speed threshold, the pitch mechanism of the target wind turbine is controlled to perform a pitch retraction action. In step C2, when the output port voltage of the target wind turbine is greater than the preset voltage limit and the rotor speed exceeds the preset speed threshold, the pitch control mechanism of the target wind turbine is retracted and the wind turbine-side converter is controlled to limit the output power.

[0077] In one embodiment, the method may also be implemented as step D1: In step D1, while performing single-unit limiting control on the target wind turbine, the power of the target wind turbine that is restricted is redistributed to other wind turbines that have not exceeded the preset voltage limit.

[0078] In one embodiment, step D1 above can also be implemented as steps D11-D14 as follows: In step D11, the voltage deviation between the output port voltage and the rated voltage of other wind turbine units that do not exceed the preset voltage limit, and the power deviation between the output power and the rated power are calculated. In step D12, the total power deviation of the entire field is calculated based on the power deviation of the target wind turbine from that of other wind turbines that have not exceeded the preset voltage limit. In step D13, the total power deviation of the entire field is allocated according to the voltage deviation of other wind turbine units that do not exceed the preset voltage limit, and a corresponding power correction command is generated. In step D14, power adjustment is performed on other wind turbines that have not exceeded the preset voltage limit according to the power correction command, so as to redistribute the restricted power of the target wind turbine. In one embodiment, step S105 above can be implemented as follows: Control the pitch mechanism of the target wind turbine to perform pitch retraction and / or control the wind turbine-side converter to limit the output power, so that the output port voltage of the target wind turbine falls back to the preset voltage limit range.

[0079] In this embodiment, the deviation between the output port voltage of the target wind turbine and a preset voltage limit is determined; the output limiting value of the target wind turbine is determined based on the deviation value. For example, the output limiting value corresponding to different deviation values ​​can be pre-calibrated, or the deviation value can be used as an input quantity through a pre-trained neural network model to output the output limiting value of the wind turbine; the pitch angle adjustment value and / or the limiting control signal of the wind turbine generator-side converter are determined based on the output limiting value; the pitch system is controlled to perform a pitch reduction action according to the pitch angle adjustment value and / or the wind turbine generator-side converter is controlled to limit the output power according to the limiting control signal, so that the output port voltage of the target wind turbine falls back to the preset voltage limit range.

[0080] Figure 6 This is a schematic diagram of the structure of a power control device according to an embodiment of this application, as shown below. Figure 6 As shown, the device includes: The receiving module 601 is used to receive active power dispatch instructions issued by the dispatching department; The determining module 602 is used to determine the single-unit power command of each wind turbine according to the active power dispatching command; The monitoring module 603 is used to execute the corresponding single-unit power command for each wind turbine and monitor the output port voltage of each wind turbine in real time. Comparison module 604 is used to compare the output port voltage of each wind turbine with a preset voltage limit. Control module 605 is used to perform single-unit amplitude limiting control on the target wind turbine when the comparison result shows that the output port voltage of the target wind turbine exceeds the preset voltage limit. The loop module 606 is used to repeatedly perform the above voltage monitoring, comparison and single-unit limiting control operations until the output voltage of all wind turbine units is controlled within a safe range.

[0081] In one embodiment, the determining module includes: The first determining submodule is used to determine the power adjustment command based on the active power dispatch command and the real-time power of the wind power system; The second determining submodule is used to determine the single-unit power command of each wind turbine through the power adjustment command.

[0082] In one embodiment, the first determining submodule is further configured to: Calculate the power deviation between the active power dispatch command and the real-time power; When the power deviation value is within the preset control range, the current power output is maintained and no power adjustment is performed. When the power deviation value exceeds the preset control range, a power adjustment command is determined based on the direction of the deviation.

[0083] In one embodiment, determining the power adjustment command based on the deviation direction includes: When the active power dispatch command is lower than the real-time power, the power adjustment command is determined to be a power reduction command; When the active power dispatch command is higher than the real-time power, the power adjustment command is determined to be a power increase command.

[0084] In one embodiment, the first determining submodule is further configured to: When it is determined that the power adjustment command is to reduce power, the power adjustment command is issued according to the active power dispatch command.

[0085] In one embodiment, the first determining submodule is further configured to: When the power adjustment command is determined to be an increase in power, the available power of each wind turbine is obtained; The total available power of the wind power system is determined based on the available power of each wind turbine unit. When the total available power is less than the power increase requirement of the dispatch, a power adjustment command is issued based on the maximum available power. If the total available power exceeds the power increase requirement of the dispatch, a power adjustment command will be issued according to the active power dispatch command.

[0086] In one embodiment, the second determining submodule is further configured to: Based on the electrical topology of the DC wind power system, the corresponding power allocation rules are determined, wherein the electrical topology includes parallel topology, series topology and series-parallel hybrid topology; The power adjustment command is allocated to each wind turbine according to the corresponding power allocation rule to obtain the single-unit power command of each wind turbine.

[0087] In one embodiment, when the wind power system is a parallel topology subsystem, the power allocation rule is as follows: The power adjustment commands are distributed proportionally according to the output port voltage of each wind turbine. The power command for each wind turbine is determined based on the allocation results.

[0088] In one embodiment, the control module further includes: The first control submodule is used to control the pitch mechanism of the target wind turbine to perform a pitch-retracting action when the output port voltage of the target wind turbine is greater than a preset voltage limit, but the rotor speed does not exceed a preset speed threshold. The second control submodule is used to control the pitch mechanism of the target wind turbine to perform a pitch-retracting action and control the wind turbine-side converter to limit the output power when the output port voltage of the target wind turbine is greater than the preset voltage limit and the rotor speed exceeds the preset speed threshold.

[0089] In one embodiment, the apparatus further includes: The allocation module is used to redistribute the restricted power of the target wind turbine to other wind turbines that have not exceeded the preset voltage limit while performing single-unit limiting control on the target wind turbine.

[0090] In one embodiment, the allocation module includes: The first calculation submodule is used to calculate the voltage deviation between the output port voltage and the rated voltage of other wind turbine units that do not exceed the preset voltage limit, as well as the power deviation between the output power and the rated power. The second calculation submodule is used to calculate the total power deviation of the entire field based on the power deviation of the target wind turbine unit from that of other wind turbine units that have not exceeded the preset voltage limit. The generation submodule is used to allocate the total power deviation of the entire field according to the voltage deviation of other wind turbine units that have not exceeded the preset voltage limit, and generate corresponding power correction instructions. The adjustment submodule is used to adjust the power of other wind turbines that have not exceeded the preset voltage limit according to the power correction command, so as to realize the redistribution of the restricted power of the target wind turbine.

[0091] Figure 7This is a schematic diagram of the hardware structure of a power control system according to one embodiment of this application, as shown below. Figure 7 As shown, the power control system includes: At least one processor 720; and, A memory 704 is communicatively connected to the at least one processor 720; wherein, The memory 704 stores instructions that can be executed by the at least one processor 720 to implement the power control method described in any of the above embodiments.

[0092] Reference Figure 7 The power control system 700 may include one or more of the following components: processing component 702, memory 704, power supply component 706, input / output (I / O) interface 708, sensor component 710, and communication component 712.

[0093] Processing component 702 typically controls the overall operation of power control system 700. Processing component 702 may include one or more processors 720 to execute instructions to complete all or part of the steps of the method described above. Furthermore, processing component 702 may include one or more modules to facilitate interaction between processing component 702 and other components. The processor 720 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0094] Memory 704 is configured to store various types of data to support the operation of power control system 700. Examples of this data include instructions for any application or method operating on power control system 700. Memory 704 can be an internal storage unit of the terminal device, such as a hard disk or memory of the terminal device. Memory 704 can also be an external storage device of the terminal device, such as a plug-in hard disk equipped on the terminal device. Memory 704 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. Memory 704 is used to store programs and data required by this application. Memory 704 can also be used to temporarily store data that has been output or will be output.

[0095] Power supply component 706 provides power to various components of power control system 700. Power supply component 706 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to power control system 700.

[0096] I / O interface 708 provides an interface between processing component 702 and peripheral interface modules, such as keyboards, click wheels, buttons, etc.

[0097] The sensor assembly 710 includes one or more sensors for providing status assessments of various aspects of the power control system 700. Additionally, the sensor assembly 710 can detect the on / off state of the power control system 700, the relative positioning of components, and the operating status of the power control system 700 or a component of the power control system 700. In some embodiments, the sensor assembly 710 may include an accelerometer, a gyroscope, a magnetometer, a pressure sensor, or a temperature sensor, etc.

[0098] Communication component 712 is configured to enable power control system 700 to provide wired or wireless communication capabilities with other devices and cloud platforms. Power control system 700 can access wireless networks based on communication standards, such as WiFi, 2G, or 3G, or combinations thereof. In one exemplary embodiment, communication component 712 receives broadcast signals or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, communication component 712 also includes a near-field communication (NFC) module to facilitate short-range communication. For example, the NFC module may be implemented based on radio frequency identification (RFID) technology, Infrared Data Association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0099] In an exemplary embodiment, the power control system 700 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the power control method described in any of the above embodiments.

[0100] This application also provides a computer-readable storage medium that, when the instructions in the storage medium are executed by a processor corresponding to the power control system, enables the power control system to implement the power control method described in any of the above embodiments.

[0101] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0102] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0103] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0104] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0105] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A power control method, characterized in that, include: Receive active power dispatch instructions from the dispatching department; The single-unit power command of each wind turbine is determined according to the active power dispatch command. Each wind turbine executes its corresponding single-unit power command and monitors the output port voltage of each wind turbine in real time; Compare the output port voltage of each wind turbine with the preset voltage limit; When the comparison results show that the output port voltage of a target wind turbine exceeds the preset voltage limit, single-unit limiting control is performed on the target wind turbine. The above voltage monitoring, comparison, and single-unit limiting control operations are repeated until the output voltage of all wind turbine units is controlled within a safe range. The step of determining the single-unit power command of each wind turbine according to the active power dispatch command includes: The power adjustment command is determined based on the active power dispatch command and the real-time power of the wind power system. The power adjustment command is used to determine the single-unit power command of each wind turbine. The process of determining the single-unit power command of each wind turbine through the power adjustment command includes: Based on the electrical topology of the DC wind power system, the corresponding power allocation rules are determined, wherein the electrical topology is a series topology. The power adjustment command is allocated to each wind turbine according to the corresponding power allocation rule to obtain the single-unit power command of each wind turbine. The power allocation rule is as follows: if there is a target wind turbine with an output port voltage exceeding the preset voltage limit, the excess voltage energy of the over-limit turbine is absorbed by the DC / DC unit to maintain the power output of the non-over-limit turbine. At the same time, the total power demand of the series cluster is recalculated, and the output parameters of the DC / DC unit are dynamically adjusted to achieve continuous power transmission of the system.

2. The method as described in claim 1, characterized in that, The step of determining the power adjustment command based on the active power dispatch command and the real-time power of the wind power system includes: When the active power dispatch command is lower than the real-time power, the power adjustment command is determined to be a power reduction command; When the active power dispatch command is higher than the real-time power, the power adjustment command is determined to be a power increase command.

3. The method as described in claim 2, characterized in that, The method further includes: When it is determined that the power adjustment command is to reduce power, the power adjustment command is issued according to the active power dispatch command.

4. The method as described in claim 2, characterized in that, The method further includes: When the power adjustment command is determined to be an increase in power, the available power of each wind turbine is obtained; The total available power of the wind power system is determined based on the available power of each wind turbine unit. When the total available power is less than the power increase requirement of the dispatch, a power adjustment command is issued based on the maximum available power. If the total available power exceeds the power increase requirement of the dispatch, a power adjustment command will be issued according to the active power dispatch command.

5. The method as described in claim 1, characterized in that, The single-unit limiting control of the target wind turbine includes: When the output port voltage of the target wind turbine is greater than the preset voltage limit, but the rotor speed does not exceed the preset speed threshold, the pitch mechanism of the target wind turbine is controlled to perform a pitch retraction action. When the output port voltage of the target wind turbine is greater than the preset voltage limit and the rotor speed exceeds the preset speed threshold, the pitch control mechanism of the target wind turbine is controlled to perform a pitch retraction action and the wind turbine-side converter is controlled to limit the output power.

6. The method as described in claim 1, characterized in that, The method further includes: While performing single-unit limiting control on the target wind turbine, the power of the target wind turbine is redistributed to other wind turbines that have not exceeded the preset voltage limit.

7. The method as described in claim 6, characterized in that, The process of redistributing the restricted power of the target wind turbine to other wind turbines that do not exceed the preset voltage limit includes: Calculate the voltage deviation between the output port voltage and the rated voltage of other wind turbine units that do not exceed the preset voltage limit, and the power deviation between the output power and the rated power. The total power deviation of the entire field is calculated based on the power deviation of the target wind turbine from that of other wind turbines that do not exceed the preset voltage limit. The total power deviation of the entire field is allocated based on the voltage deviation of other wind turbine units that do not exceed the preset voltage limit, and corresponding power correction instructions are generated. According to the power correction command, the power of other wind turbines that have not exceeded the preset voltage limit is adjusted to redistribute the restricted power of the target wind turbine.

8. A power control device for use in the power control method as described in any one of claims 1-7, characterized in that, include: The receiving module is used to receive active power dispatch instructions issued by the dispatching department; The determination module is used to determine the single-unit power command of each wind turbine according to the active power dispatch command; The monitoring module is used to execute the corresponding single-unit power command for each wind turbine and monitor the output port voltage of each wind turbine in real time. The comparison module is used to compare the output port voltage of each wind turbine with the preset voltage limit. The control module is used to perform single-unit limiting control on the target wind turbine when the output port voltage of the target wind turbine exceeds the preset voltage limit in the comparison result. The loop module is used to repeatedly perform the above voltage monitoring, comparison and single-unit limiting control operations until the output voltage of all wind turbine units is controlled within a safe range.

9. A power control system, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to implement the power control method as described in any one of claims 1-7.

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