Voltage distribution control method, device, equipment and medium for offshore wind farm

Abstract

The present disclosure proposes a voltage distribution control method, device, equipment and medium for an offshore wind farm. The offshore wind farm at least includes: an offshore sending-end converter station and a wind turbine grid-side converter, and the method includes: obtaining the maximum reactive power of the wind turbine converter to which the wind turbine grid-side converter belongs, and the maximum reactive power of the flexible direct current system to which the offshore sending-end converter station belongs, and determining the target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system, and then determining the target reactive power setting value of the grid-connected point in the offshore wind farm, and then controlling the operation of the offshore sending-end converter station and the wind turbine grid-side converter according to the target reactive power setting value and the target power demand ratio, thereby effectively reducing the impact of the strong randomness, high intermittency and large volatility of offshore wind power on the operation of the offshore wind farm, and effectively improving the safety and stability of offshore wind power grid connection.

Description

Technical Field

[0001] The present disclosure relates to the technical field of renewable energy power generation, and in particular to a voltage distribution control method, device, electronic equipment and storage medium for an offshore wind farm. Background Art

[0002] Compared with onshore wind power, offshore wind power has unique advantages such as stable wind energy resources, no land occupation, and good consumption conditions. At present, the grid-connected modes of offshore wind power transmission are mainly divided into two categories: high-voltage AC transmission and high-voltage DC transmission. Among them, high-voltage DC transmission adopts flexible DC transmission technology based on voltage source converter. Flexible DC transmission technology refers to the effective isolation of the internal AC system of the wind farm from the external large power grid.

[0003] In the related technologies, the voltage coordination control strategy adopted by offshore wind power through the flexible direct current system at the offshore grid connection point of the wind turbine is to adopt a fixed DC voltage and fixed reactive power control strategy on the wind turbine grid side, and a fixed AC voltage and fixed frequency control strategy at the offshore converter station of the flexible direct current system.

[0004] In this way, since the reactive power setting value of the wind turbine is generally 0 and the bus voltage at the grid connection point all comes from the flexible DC system, the reactive power regulation capability of the wind turbine cannot be fully utilized. Summary of the invention

[0005] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0006] To this end, the purpose of the present disclosure is to propose a voltage distribution control method, device, electronic device and storage medium for offshore wind farms, which can effectively reduce the impact of the strong randomness, high intermittency and large volatility of offshore wind power on the operation of offshore wind farms, and effectively improve the safety and stability of offshore wind power grid connection.

[0007] The first aspect of the present disclosure proposes a voltage distribution control method for an offshore wind farm, wherein the offshore wind farm comprises at least an offshore sending-end converter station and a wind turbine grid-side converter, and the method comprises: obtaining the maximum reactive power of the wind turbine converter to which the wind turbine grid-side converter belongs, and the maximum reactive power of the flexible direct current system to which the offshore sending-end converter station belongs, and determining a target power demand ratio based on the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system, and then determining a target reactive power setting value of the grid-connected point in the offshore wind farm, and then controlling the operation of the offshore sending-end converter station and the wind turbine grid-side converter based on the target reactive power setting value and the target power demand ratio.

[0008] The voltage distribution control method for an offshore wind farm proposed in the first aspect of the embodiment of the present disclosure obtains the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter and the maximum reactive power of the flexible direct current system belonging to the offshore sending-end converter station, and determines the target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system, and then determines the target reactive power setting value of the grid-connected point in the offshore wind farm, and then controls the operation of the offshore sending-end converter station and the wind turbine grid-side converter according to the target reactive power setting value and the target power demand ratio. As a result, the strong randomness, high intermittency and large volatility of offshore wind power can be effectively reduced. The impact on the operation of the offshore wind farm can be effectively improved, and the safety and stability of offshore wind power grid connection can be effectively improved.

[0009] The second aspect of the present disclosure proposes a voltage distribution control device for an offshore wind farm, the offshore wind farm at least comprising: an offshore sending-end converter station and a wind turbine grid-side converter, the device comprising: an acquisition module, used to acquire the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter, and the maximum reactive power of the flexible direct current system belonging to the offshore sending-end converter station; a first determination module, used to determine the target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system; a second determination module, used to determine the target reactive power setting value of the grid-connected point in the offshore wind farm; a control module, used to control the operation of the offshore sending-end converter station and the wind turbine grid-side converter according to the target reactive power setting value and the target power demand ratio.

[0010] The voltage distribution control device for an offshore wind farm proposed in the second aspect of the embodiment of the present disclosure obtains the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter and the maximum reactive power of the flexible direct current system belonging to the offshore sending-end converter station, and determines the target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system, and then determines the target reactive power setting value of the grid-connected point in the offshore wind farm, and then controls the operation of the offshore sending-end converter station and the wind turbine grid-side converter according to the target reactive power setting value and the target power demand ratio. As a result, the impact of the strong randomness, high intermittency and large volatility of offshore wind power on the operation of offshore wind farms can be effectively reduced, and the safety and stability of offshore wind power grid connection can be effectively improved.

[0011] The third aspect embodiment of the present disclosure proposes an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the voltage distribution control method for an offshore wind farm proposed in the first aspect embodiment of the present disclosure is implemented.

[0012] The fourth aspect embodiment of the present disclosure proposes a non-temporary computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the voltage distribution control method for an offshore wind farm as proposed in the first aspect embodiment of the present disclosure.

[0013] The fifth aspect of the present disclosure provides a computer program product. When an instruction processor in the computer program product executes, it performs the voltage distribution control method for an offshore wind farm as provided in the first aspect of the present disclosure.

[0014] 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

[0015] 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:

[0016] Figure 1 It is a flow chart of a voltage distribution control method for an offshore wind farm proposed in an embodiment of the present disclosure;

[0017] Figure 2 It is a structural schematic diagram of an offshore wind power flexible direct current transmission system proposed in one embodiment of the present disclosure;

[0018] Figure 3 It is a schematic diagram of a process for determining a target reactive power setting value proposed in an embodiment of the present disclosure;

[0019] Figure 4 is a flow chart of a voltage distribution control method for an offshore wind farm proposed in another embodiment of the present disclosure;

[0020] Figure 5 This is a schematic diagram of the control flow of an offshore sending-end converter station proposed in an embodiment of the present disclosure;

[0021] Figure 6 It is a schematic diagram of the control flow of a wind turbine grid-side converter proposed in an embodiment of the present disclosure;

[0022] Figure 7 It is a structural schematic diagram of a voltage distribution control device for an offshore wind farm proposed in one embodiment of the present disclosure;

[0023] Figure 8 A block diagram of an exemplary electronic device suitable for implementing embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0024] Embodiments of the present disclosure are described in detail below, and examples of the embodiments 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 only used to explain the present disclosure, and should not be construed as limitations on the present disclosure. On the contrary, the embodiments of the present disclosure include all changes, modifications, and equivalents that fall within the spirit and connotation of the appended claims.

[0025] It should be noted that the processes of obtaining, collecting, storing, using, and processing information in the technical solution disclosed in this disclosure comply with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0026] Figure 1 It is a flow chart of a voltage distribution control method for an offshore wind farm proposed in one embodiment of the present disclosure.

[0027] It should be noted that the executor of the voltage distribution control method for offshore wind farms in this embodiment is a voltage distribution control device for offshore wind farms, which can be implemented by software and / or hardware. The device can be configured in an electronic device, which may include but is not limited to a terminal, a server, etc.

[0028] The voltage dispersion control method for an offshore wind farm described in the embodiment of the present disclosure can be used in an offshore wind power flexible direct current transmission system. In order to better understand the voltage dispersion control method for an offshore wind farm disclosed in the embodiment of the present disclosure, the offshore wind power flexible direct current transmission system to which the embodiment of the present disclosure is applicable is first described below.

[0029] See also Figure 2 , Figure 2 It is a structural schematic diagram of an offshore wind power flexible direct current transmission system proposed in an embodiment of the present disclosure. The offshore wind power flexible direct current transmission system at least includes: a wind turbine converter, the wind power converter includes: a wind turbine grid-side converter and a wind turbine machine-side converter, and the flexible direct current system includes: an offshore sending-end converter station and an onshore sending-end converter station.

[0030] like Figure 1 As shown, the voltage distribution control method for an offshore wind farm comprises:

[0031] S101: Obtain the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter and the maximum reactive power of the flexible direct current system belonging to the offshore sending-end converter station.

[0032] Among them, the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter can be used to characterize the reactive power regulation capability of the wind turbine grid-side converter. Correspondingly, the maximum reactive power of the flexible DC system belonging to the offshore sending-end converter station can be used to characterize the reactive power regulation capability of the flexible DC system.

[0033] In the embodiments of the present disclosure, the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter can be obtained, and the maximum reactive power of the flexible DC system belonging to the offshore sending-end converter station can be obtained. Then, the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible DC system can be combined to execute the subsequent voltage distribution control method for the offshore wind farm. For details, please refer to the subsequent embodiments.

[0034] S102: Determine a target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible DC system.

[0035] Among them, the target power demand ratio refers to the power share coefficient required by each system in the offshore wind farm to maintain a good operating state. The power share coefficient can be, for example, the power share coefficient required by the offshore sending-end converter station, the power share coefficient required by the wind turbine grid-side converter, etc., and there is no restriction on this.

[0036] After obtaining the maximum reactive power of the wind turbine converter to which the wind turbine network-side converter belongs and the maximum reactive power of the flexible DC system to which the offshore sending-end converter station belongs, the disclosed embodiment can determine the power ratio required by the offshore sending-end converter station and the power ratio required by the wind turbine network-side converter according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible DC system, and use the aforementioned power ratio required by the offshore sending-end converter station and the power ratio required by the wind turbine network-side converter together as the target power demand ratio.

[0037] S103: Determine a target reactive power setting value of a grid connection point in an offshore wind farm.

[0038] Among them, during the execution of the voltage distribution control method for offshore wind farms, the power value processed according to the pre-set demand of the grid connection point in the offshore wind farm can be called the target reactive power setting value, and the target reactive power setting value can be the reactive power required by the grid connection point in the offshore wind farm.

[0039] In some embodiments, the target reactive power setting value of the grid connection point in the offshore wind farm can be determined by combining the historical operating data of each system in the offshore wind farm, determining the sum of the reactive power required by each system in the offshore wind farm, and using the sum of the reactive power required by each system in the offshore wind farm determined above as the target reactive power setting value.

[0040] In the embodiments of the present disclosure, the target reactive power setting value of the grid connection point in the offshore wind farm is determined by pre-providing a corresponding data transmission interface by the grid connection point in the offshore wind farm. Then, based on the corresponding data transmission interface pre-provided by the grid connection point in the offshore wind farm, a preset reactive power can be received, and the reactive power can be used as the target reactive power setting value of the grid connection point in the offshore wind farm. Then, the target reactive power setting value can be combined to trigger the execution of a subsequent voltage distribution control method for the offshore wind farm. For details, please refer to the subsequent embodiments.

[0041] Optionally, in some embodiments, determining the target reactive power setting value of the grid connection point in the offshore wind farm can be performed by obtaining the rated voltage value and the measured voltage value of the AC bus in the grid connection point, and inputting the voltage difference between the rated voltage value and the measured voltage value into a proportional-integral controller to obtain the target reactive power setting value output by the proportional-integral controller.

[0042] In the embodiments of the present disclosure, see Figure 3 , Figure 3 is a schematic diagram of a process for determining a target reactive power setting value proposed in an embodiment of the present disclosure. That is, in the embodiment of the present disclosure, the rated voltage value U of the AC busbar in the grid connection point may be determined first. ACref_ r, and determine the measured voltage value U of the AC busbar at the grid connection point AC_r , and then, we can ACref_ r and U AC_r The voltage difference is obtained by subtracting the voltage difference, and the voltage difference is input into the proportional integral controller to obtain the target reactive power setting value Q required by the grid connection point output by the proportional integral controller. ref_all .

[0043] S104: Control the operation of the offshore sending-end converter station and the wind turbine grid-side converter according to the target reactive power setting value and the target power demand ratio.

[0044] After determining the target reactive power setting value and target power demand ratio of the grid connection point in the offshore wind farm, the embodiment of the present disclosure can control the operation of the offshore sending-end converter station and the wind turbine grid-side converter according to the target reactive power setting value and the target power demand ratio.

[0045] In some embodiments, the operation of the offshore sending-end converter station and the wind turbine network-side converter is controlled according to the target reactive power setting value and the target power demand ratio. The operating power of the offshore sending-end converter station and the operating power of the wind turbine network-side converter are determined according to the target reactive power setting value and the target power demand ratio, and the offshore sending-end converter station is controlled to operate with the aforementioned determined operating power of the offshore sending-end converter station, and the wind turbine network-side converter is controlled to operate with the aforementioned determined operating power of the wind turbine network-side converter. There is no limitation to this.

[0046] In the disclosed embodiment, by obtaining the maximum reactive power of the wind turbine converter to which the wind turbine grid-side converter belongs and the maximum reactive power of the flexible direct current system to which the offshore sending-end converter station belongs, and according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system, the target power demand ratio is determined, and then the target reactive power setting value of the grid connection point in the offshore wind farm is determined, and then according to the target reactive power setting value and the target power demand ratio, the operation of the offshore sending-end converter station and the wind turbine grid-side converter is controlled, thereby effectively reducing the impact of the strong randomness, high intermittency and large volatility of offshore wind power on the operation of offshore wind farms, and effectively improving the safety and stability of offshore wind power grid connection.

[0047] Figure 4 It is a flow chart of a voltage distribution control method for an offshore wind farm proposed in another embodiment of the present disclosure.

[0048] like Figure 4 As shown, the voltage distribution control method for an offshore wind farm comprises:

[0049] S401: Obtain the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter and the maximum reactive power of the flexible direct current system belonging to the offshore sending-end converter station.

[0050] S402: Determine a target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible DC system.

[0051] S403: Determine a target reactive power setting value of a grid connection point in an offshore wind farm.

[0052] The specific description of S401 - S403 can be found in the above embodiment, which will not be repeated here.

[0053] S404: Determine a first reactive power setting value of the offshore sending-end converter station according to the first power demand ratio and the target reactive power setting value.

[0054] After determining the target reactive power setting value of the grid connection point in the offshore wind farm, the embodiment of the present disclosure can determine the reactive power setting value required by the offshore sending-end converter station according to the first power demand ratio and the target reactive power setting value. This reactive power setting value can be called the first reactive power setting value.

[0055] In the embodiment of the present disclosure, after determining the first power demand ratio K, the product of the first power demand ratio and the target reactive power setting value (KQ ref_all ) is used as the first reactive power setting value of the offshore sending-end converter station.

[0056] S405: Determine a second reactive power setting value of the wind turbine grid-side converter according to the second power demand ratio and the target reactive power setting value.

[0057] After determining the target reactive power setting value of the grid connection point in the offshore wind farm, the embodiment of the present disclosure can determine the reactive power setting value required by the wind turbine grid-side converter according to the first power demand ratio and the target reactive power setting value. This reactive power setting value can be called the second reactive power setting value.

[0058] In the embodiment of the present disclosure, after determining the second power demand ratio (1-K), the product of the second power demand ratio and the target reactive power setting value ((1-K)Q ref_all ) is used as the second reactive power setting value of the wind turbine grid-side converter.

[0059] S406: Controlling the operation of the offshore sending-end converter station according to the first reactive power setting value.

[0060] In the embodiment of the present disclosure, when determining the first reactive power setting value (KQ ref_all ) After that, the operation of the offshore sending-end converter station can be controlled according to the first reactive power setting value.

[0061] In some embodiments, the operation of the offshore sending-end converter station is controlled according to the first reactive power setting value, and the operating state of the offshore sending-end converter station can be monitored to ensure that the offshore sending-end converter station can operate at the first reactive power setting value (KQ ref_all )run.

[0062] Optionally, in some embodiments, the rated frequency value, measured frequency value and first reactive power measurement value of the offshore sending-end converter station are determined, and the frequency difference between the rated frequency value and the measured frequency value is input into the frequency controller to obtain the first component current value of the offshore sending-end converter station output by the frequency controller, and then the first power difference between the first reactive power setting value and the first reactive power measurement value is input into the reactive power controller to obtain the second component current value of the offshore sending-end converter station output by the reactive power controller, and then the first component current value and the second component current value are input into the inner loop current controller to obtain the first operating voltage value of the offshore sending-end converter station output by the inner loop current controller, and the offshore sending-end converter station is controlled to operate at the first operating voltage value.

[0063] In the embodiments of the present disclosure, see Figure 5 , Figure 5 is a schematic diagram of the control flow of the offshore sending-end converter station proposed in an embodiment of the present disclosure, which may be used to determine the rated frequency value f of the offshore sending-end converter station. ACref_r and the measured frequency value f AC_r , and for the rated frequency value f ACref_rand the measured frequency value f AC_r The frequency difference between the rated frequency value and the measured frequency value is obtained by subtracting the frequency difference, and then the frequency difference is input into the frequency controller to obtain the first component current value (d-axis component current value I dref_r ).

[0064] Then, the first reactive power measurement value Q of the offshore sending-end converter station can be determined r , and for KQ ref_all and Q r The first power difference between the rated frequency value and the measured frequency value is determined by subtraction, and the first power difference is input into the reactive power controller to obtain the second component current value (q-axis component current value I qref_r ), and then the first component current value I dref_r and the second component current value I qref_r Input to the inner loop current controller to obtain the first operating voltage value (three-phase AC voltage modulation wave reference value U aref_r , U bref_r , U cref_r ), and then control the offshore sending-end converter station to operate at the first operating voltage value.

[0065] S407: Controlling the operation of the wind turbine grid-side converter according to the second reactive power setting value.

[0066] In the embodiment of the present disclosure, the second reactive power setting value ((1-K)Q ref_all ) After that, the operation of the wind turbine grid-side converter can be controlled according to the second reactive power setting value.

[0067] In some embodiments, the operation of the wind turbine grid-side converter is controlled according to the second reactive power setting value, and the operation state of the wind turbine grid-side converter is monitored to ensure that the wind turbine grid-side converter can achieve the second reactive power setting value ((1-K)Q ref_all )run.

[0068] Optionally, in some embodiments, the operation of the wind turbine network-side converter is controlled according to the second reactive power setting value, which can be to determine the rated DC voltage value, measured DC voltage value and second reactive power measurement value of the wind turbine network-side converter, and input the DC voltage difference between the rated DC voltage value and the measured DC voltage value into a DC voltage controller to obtain a third component current value of the wind turbine network-side converter output by the DC voltage controller, and then input the second power difference between the second reactive power setting value and the second reactive power measurement value into the reactive power controller to obtain a fourth component current value of the wind turbine network-side converter output by the reactive power controller, and input the third component current value and the fourth component current value into the inner loop current controller to obtain the second operating voltage value of the wind turbine network-side converter output by the inner loop current controller, and then control the wind turbine network-side converter to operate at the second operating voltage value.

[0069] In the embodiments of the present disclosure, see Figure 6 , Figure 6 is a schematic diagram of a control flow of a wind turbine grid-side converter proposed in an embodiment of the present disclosure, which may be used to determine the rated DC voltage value U of the wind turbine grid-side converter. dcref , measure the DC voltage value U dc , and for the rated DC voltage value U dcref And measure the DC voltage value U dc The DC voltage difference between the rated DC voltage value and the measured DC voltage value is determined by performing a subtraction, and then the DC voltage difference is input into the DC voltage controller to obtain the third component current value (d-axis component current value I dref_i ).

[0070] Then, the second reactive power measurement value Q of the wind turbine grid-side converter can be determined: Ac , and (1-K)Q ref_all and Q Ac The second power difference is determined by performing a difference, and the second power difference is input into the reactive power controller to obtain the fourth component current value (q-axis component current value I qref_i ), and then I dref_i and I qref_i The three-phase AC voltage modulation wave reference value U aref_i , U bref_i , U cref_i ), and then control the wind turbine grid-side converter to operate at the second operating voltage value.

[0071] In the disclosed embodiment, the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter and the maximum reactive power of the flexible direct current system belonging to the offshore sending-end converter station are obtained, and the target power demand ratio is determined according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system, and then the target reactive power setting value of the grid connection point in the offshore wind farm is determined, and then the first reactive power setting value of the offshore sending-end converter station is determined according to the first power demand ratio and the target reactive power setting value, and then according to the second power demand ratio and the target reactive power setting value, Determine the second reactive power setting value of the wind turbine grid-side converter, and then control the operation of the offshore sending-end converter station according to the first reactive power setting value, and control the operation of the wind turbine grid-side converter according to the second reactive power setting value. In this way, the wind turbine grid-side converter and the offshore sending-end converter station can each bear a certain amount of reactive power, thereby realizing voltage decentralized control of the offshore wind farm, which can effectively reduce the impact of the strong randomness, high intermittency and large volatility of offshore wind power on the operation of the offshore wind farm, and effectively improve the safety and stability of offshore wind power grid connection.

[0072] Figure 7 It is a structural schematic diagram of a voltage distribution control device for an offshore wind farm proposed in one embodiment of the present disclosure.

[0073] An offshore wind farm includes at least: an offshore sending-end converter station and a wind turbine grid-side converter.

[0074] like Figure 7 As shown, the voltage distribution control device 70 for an offshore wind farm comprises:

[0075] The acquisition module 701 is used to acquire the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter and the maximum reactive power of the flexible direct current system belonging to the offshore sending-end converter station;

[0076] The first determination module 702 is used to determine the target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system;

[0077] The second determination module 703 is used to determine the target reactive power setting value of the grid connection point in the offshore wind farm;

[0078] The control module 704 is used to control the operation of the offshore sending-end converter station and the wind turbine grid-side converter according to the target reactive power setting value and the target power demand ratio.

[0079] In some embodiments of the present disclosure, the first determining module 702 further includes:

[0080] Determine the first power demand ratio of the offshore sending-end converter station according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible DC system; or

[0081] Determine a second power demand ratio of the wind turbine grid-side converter according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system, wherein the sum of the first demand voltage ratio and the second power demand ratio is 1;

[0082] The first power requirement ratio and the second power requirement ratio are used together as the target power requirement ratio.

[0083] In some embodiments of the present disclosure, the control module 704 is further configured to:

[0084] Determining a first reactive power setting value of the offshore sending-end converter station according to the first power demand ratio and the target reactive power setting value;

[0085] Determining a second reactive power setting value of the wind turbine grid-side converter according to the second power demand ratio and the target reactive power setting value;

[0086] According to the first reactive power setting value, the operation of the offshore sending-end converter station is controlled;

[0087] According to the second reactive power setting value, the operation of the wind turbine grid-side converter is controlled.

[0088] In some embodiments of the present disclosure, the control module 704 is further configured to:

[0089] Determining a rated frequency value, a measured frequency value, and a first reactive power measurement value of an offshore sending-end converter station;

[0090] Inputting the frequency difference between the rated frequency value and the measured frequency value into the frequency controller to obtain the first component current value of the offshore sending-end converter station output by the frequency controller;

[0091] Inputting a first power difference between a first reactive power setting value and a first reactive power measurement value into a reactive power controller to obtain a second component current value of an offshore sending-end converter station output by the reactive power controller;

[0092] Inputting the first component current value and the second component current value into the inner loop current controller to obtain a first operating voltage value of the offshore sending-end converter station output by the inner loop current controller;

[0093] The offshore sending-end converter station is controlled to operate at the first operating voltage value.

[0094] In some embodiments of the present disclosure, the control module 704 is further configured to:

[0095] Determine a rated DC voltage value, a measured DC voltage value, and a second reactive power measurement value of a wind turbine grid-side converter;

[0096] Inputting a DC voltage difference between a rated DC voltage value and a measured DC voltage value into a DC voltage controller to obtain a third component current value of a wind turbine grid-side converter output by the DC voltage controller;

[0097] Inputting a second power difference between the second reactive power setting value and the second reactive power measurement value into the reactive power controller to obtain a fourth component current value of the wind turbine grid-side converter output by the reactive power controller;

[0098] Inputting the third component current value and the fourth component current value into the inner loop current controller to obtain a second operating voltage value of the wind turbine grid-side converter output by the inner loop current controller;

[0099] The wind turbine grid-side converter is controlled to operate at a second operating voltage value.

[0100] In some embodiments of the present disclosure, the second determining module 703 is further configured to:

[0101] Obtain the rated voltage value and measured voltage value of the AC busbar in the grid connection point;

[0102] The voltage difference between the rated voltage value and the measured voltage value is input into the proportional-integral controller to obtain the target reactive power setting value output by the proportional-integral controller.

[0103] With the above Figures 1 to 6 Corresponding to the voltage distribution control method for an offshore wind farm provided in the embodiment, the present disclosure also provides a voltage distribution control device for an offshore wind farm. Since the voltage distribution control device for an offshore wind farm provided in the embodiment of the present disclosure is similar to the above-mentioned voltage distribution control method, the present disclosure also provides a voltage distribution control device for an offshore wind farm. Figures 1 to 6 The voltage dispersion control method for offshore wind farms provided in the embodiment corresponds to this, so the implementation of the voltage dispersion control method for offshore wind farms is also applicable to the voltage dispersion control device for offshore wind farms provided in the embodiment of the present disclosure, and will not be described in detail in the embodiment of the present disclosure.

[0104] In this embodiment, by obtaining the maximum reactive power of the wind turbine converter to which the wind turbine grid-side converter belongs and the maximum reactive power of the flexible DC system to which the offshore sending-end converter station belongs, and according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible DC system, the target power demand ratio is determined, and then the target reactive power setting value of the grid connection point in the offshore wind farm is determined, and then according to the target reactive power setting value and the target power demand ratio, the operation of the offshore sending-end converter station and the wind turbine grid-side converter is controlled. In this way, the impact of the strong randomness, high intermittency and large volatility of offshore wind power on the operation of offshore wind farms can be effectively reduced, and the safety and stability of offshore wind power grid connection can be effectively improved.

[0105] In order to implement the above embodiments, the present disclosure also proposes an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the voltage distribution control method for offshore wind farms proposed in the above embodiments of the present disclosure is implemented.

[0106] In order to implement the above embodiments, the present disclosure also proposes a non-temporary computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the voltage distribution control method for an offshore wind farm proposed in the above embodiments of the present disclosure is implemented.

[0107] In order to implement the above embodiments, the present disclosure further proposes a computer program product. When an instruction processor in the computer program product executes, the voltage distribution control method for an offshore wind farm proposed in the above embodiments of the present disclosure is executed.

[0108] Figure 8 A block diagram of an exemplary electronic device suitable for implementing embodiments of the present disclosure is shown. Figure 8 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0109] like Figure 8 As shown, the electronic device is in the form of a general-purpose computing device. The components of the electronic device may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 connecting different system components (including the system memory 28 and the processing unit 16).

[0110] The bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor or a local bus using any of a variety of bus structures. For example, these architectures include but are not limited to Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus and Peripheral Component Interconnection (PCI) bus.

[0111] Electronic devices typically include a variety of computer system readable media. These media can be any available media that can be accessed by the electronic device, including volatile and non-volatile media, removable and non-removable media.

[0112] The memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The electronic device may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Figure 8 Not shown, often called a "hard drive").

[0113] although Figure 8 Not shown in the figure, a disk drive for reading and writing a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing a removable non-volatile optical disk (e.g., a compact disc read only memory (hereinafter referred to as: CD-ROM), a digital versatile disc read only memory (hereinafter referred to as: DVD-ROM) or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present disclosure.

[0114] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in the memory 28, such program modules 42 including but not limited to an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 42 generally perform the functions and / or methods of the embodiments described in the present disclosure.

[0115] The electronic device may also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), may also communicate with one or more devices that enable a user to interact with the electronic device, and / or may communicate with any device that enables the electronic device to communicate with one or more other computing devices (e.g., network card, modem, etc.). Such communication may be performed through an input / output (I / O) interface 22. Furthermore, the electronic device may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 20. As shown, the network adapter 20 communicates with other modules of the electronic device through a bus 18. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0116] The processing unit 16 executes various functional applications and data processing by running the programs stored in the system memory 28 , for example, implementing the voltage distribution control method for an offshore wind farm mentioned in the above-mentioned embodiment.

[0117] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0118] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

[0119] It should be noted that, in the description of the present disclosure, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present disclosure, unless otherwise specified, the meaning of "plurality" is two or more.

[0120] 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 specific logical function or process, and the scope of the preferred embodiments of the present disclosure includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present disclosure belong.

[0121] 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, it can be implemented by any one of the following technologies known in the art or their combination: 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.

[0122] 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.

[0123] 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.

[0124] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0125] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 representation of the above terms does 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.

[0126] Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A voltage distribution control method for an offshore wind farm, characterized in that: The offshore wind farm at least comprises: an offshore sending-end converter station and a wind turbine grid-side converter, and the method comprises: Obtaining the maximum reactive power of the wind turbine converter to which the wind turbine grid-side converter belongs, and the maximum reactive power of the flexible direct current system to which the offshore sending-end converter station belongs; Determining a target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system; Determining a target reactive power setting value of a grid connection point in the offshore wind farm; The operation of the offshore sending-end converter station and the wind turbine grid-side converter is controlled according to the target reactive power setting value and the target power demand ratio.

2. The method according to claim 1, characterized in that The determining of the target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system comprises: Determining a first power demand ratio of the offshore sending-end converter station according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible DC system; or Determine a second power demand ratio of the wind turbine grid-side converter according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system, wherein the sum of the first power demand ratio and the second power demand ratio is 1; The first power requirement ratio and the second power requirement ratio are used together as the target power requirement ratio.

3. The method according to claim 2, characterized in that The controlling the operation of the offshore sending-end converter station and the wind turbine grid-side converter according to the target reactive power setting value and the target power demand ratio includes: Determining a first reactive power setting value of the offshore sending-end converter station according to the first power demand ratio and the target reactive power setting value; Determining a second reactive power setting value of the wind turbine grid-side converter according to the second power demand ratio and the target reactive power setting value; Controlling the operation of the offshore sending-end converter station according to the first reactive power setting value; The operation of the wind turbine grid-side converter is controlled according to the second reactive power setting value.

4. The method according to claim 3, characterized in that The step of controlling the operation of the offshore sending-end converter station according to the first reactive power setting value comprises: Determining a rated frequency value, a measured frequency value, and a first reactive power measurement value of the offshore sending-end converter station; Inputting the frequency difference between the rated frequency value and the measured frequency value into a frequency controller to obtain the first component current value of the offshore sending-end converter station output by the frequency controller; Inputting a first power difference between the first reactive power setting value and the first reactive power measurement value into a reactive power controller to obtain a second component current value of the offshore sending-end converter station output by the reactive power controller; Inputting the first component current value and the second component current value into an inner loop current controller to obtain a first operating voltage value of the offshore sending-end converter station output by the inner loop current controller; The offshore sending-end converter station is controlled to operate at the first operating voltage value.

5. The method according to claim 4, characterized in that The step of controlling the operation of the wind turbine grid-side converter according to the second reactive power setting value includes: Determining a rated DC voltage value, a measured DC voltage value, and a second reactive power measurement value of the wind turbine grid-side converter; Inputting a DC voltage difference between the rated DC voltage value and the measured DC voltage value into a DC voltage controller to obtain a third component current value of the wind turbine grid-side converter output by the DC voltage controller; Inputting a second power difference between the second reactive power setting value and the second reactive power measurement value into the reactive power controller to obtain a fourth component current value of the wind turbine grid-side converter output by the reactive power controller; Inputting the third component current value and the fourth component current value into the inner loop current controller to obtain a second operating voltage value of the wind turbine grid-side converter output by the inner loop current controller; The wind turbine grid-side converter is controlled to operate at the second operating voltage value.

6. The method according to claim 1, characterized in that The determining of the target reactive power setting value of the grid connection point in the offshore wind farm comprises: Obtaining a rated voltage value and a measured voltage value of the AC bus in the grid connection point; The voltage difference between the rated voltage value and the measured voltage value is input into a proportional-integral controller to obtain the target reactive power setting value output by the proportional-integral controller.

7. A voltage distribution control device for an offshore wind farm, characterized in that: The offshore wind farm at least comprises: an offshore sending-end converter station and a wind turbine grid-side converter, and the device comprises: An acquisition module, used to acquire the maximum reactive power of the wind turbine converter belonging to the wind turbine grid-side converter, and the maximum reactive power of the flexible direct current system belonging to the offshore sending-end converter station; A first determination module is used to determine a target power demand ratio according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system; A second determination module is used to determine a target reactive power setting value of a grid connection point in the offshore wind farm; A control module is used to control the operation of the offshore sending-end converter station and the wind turbine grid-side converter according to the target reactive power setting value and the target power demand ratio.

8. The device according to claim 7, characterized in that The first determining module is further used for: Determining a first power demand ratio of the offshore sending-end converter station according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible DC system; or Determine a second power demand ratio of the wind turbine grid-side converter according to the maximum reactive power of the wind turbine converter and the maximum reactive power of the flexible direct current system, wherein the sum of the first power demand ratio and the second power demand ratio is 1; The first power requirement ratio and the second power requirement ratio are used together as the target power requirement ratio.

9. The device according to claim 8, characterized in that The control module is also used for: Determining a first reactive power setting value of the offshore sending-end converter station according to the first power demand ratio and the target reactive power setting value; Determining a second reactive power setting value of the wind turbine grid-side converter according to the second power demand ratio and the target reactive power setting value; Controlling the operation of the offshore sending-end converter station according to the first reactive power setting value; The operation of the wind turbine grid-side converter is controlled according to the second reactive power setting value.

10. The device according to claim 9, characterized in that The control module is also used for: Determining a rated frequency value, a measured frequency value, and a first reactive power measurement value of the offshore sending-end converter station; Inputting the frequency difference between the rated frequency value and the measured frequency value into a frequency controller to obtain the first component current value of the offshore sending-end converter station output by the frequency controller; Inputting a first power difference between the first reactive power setting value and the first reactive power measurement value into a reactive power controller to obtain a second component current value of the offshore sending-end converter station output by the reactive power controller; Inputting the first component current value and the second component current value into an inner loop current controller to obtain a first operating voltage value of the offshore sending-end converter station output by the inner loop current controller; The offshore sending-end converter station is controlled to operate at the first operating voltage value.

11. The device according to claim 10, characterized in that The control module is also used for: Determining a rated DC voltage value, a measured DC voltage value, and a second reactive power measurement value of the wind turbine grid-side converter; Inputting a DC voltage difference between the rated DC voltage value and the measured DC voltage value into a DC voltage controller to obtain a third component current value of the wind turbine grid-side converter output by the DC voltage controller; Inputting a second power difference between the second reactive power setting value and the second reactive power measurement value into the reactive power controller to obtain a fourth component current value of the wind turbine grid-side converter output by the reactive power controller; Inputting the third component current value and the fourth component current value into the inner loop current controller to obtain a second operating voltage value of the wind turbine grid-side converter output by the inner loop current controller; The wind turbine grid-side converter is controlled to operate at the second operating voltage value.

12. The device according to claim 7, characterized in that The second determining module is further used for: Obtaining a rated voltage value and a measured voltage value of the AC bus in the grid connection point; The voltage difference between the rated voltage value and the measured voltage value is input into a proportional-integral controller to obtain the target reactive power setting value output by the proportional-integral controller.

13. An electronic device, comprising: 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, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 6.

14. A non-transitory computer-readable storage medium storing computer instructions, wherein: The computer instructions are used to cause the computer to execute the method according to any one of claims 1 to 6.

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