Reactive voltage control method and device based on series wind farm

Abstract

The application provides a reactive power and voltage control method and device based on a series wind farm. The reactive power and voltage control method based on the series wind farm comprises the following steps: determining total reactive power according to grid-connected point data at a previous adjustment time, grid-connected point data at a current adjustment time and a current voltage deviation value; determining wind turbine reactive power adjustment power and reactive power compensation adjustment power according to a wind turbine reactive power adjustment value, a reactive power compensation adjustment value and the total reactive power; sending a wind turbine reactive power adjustment instruction to a wind turbine according to the wind turbine reactive power adjustment power, so that the wind turbine adjusts reactive power according to the wind turbine reactive power adjustment instruction; and sending a reactive power compensation adjustment instruction to a reactive power compensation device according to the reactive power compensation adjustment power, so that the reactive power compensation device adjusts reactive power according to the reactive power compensation adjustment instruction. The application can coordinate reactive power equipment in the wind farm, suppress possible reactive power circulation in the series wind farm and improve the safe operation level of the reactive power and voltage of the wind farm.

Description

Technical Field

[0001] This invention relates to the field of reactive power voltage control technology, specifically to a reactive power voltage control method and device based on a series-connected wind farm. Background Technology

[0002] With the continuous increase in the scale of new energy grid connection, and considering the economics of power grid construction, multiple new energy power plants connected in series to the collection station will become the main topology of new energy collection systems. However, due to significant differences between the operating characteristics of new energy and the topology of the collection network compared to traditional power plants, series-connected new energy power plants experience large voltage fluctuations and low qualification rates. Traditional reactive power and voltage control strategies for these power plants are insufficient to effectively suppress voltage fluctuations and reactive power circulation, thus failing to provide effective guarantees for the safe and stable operation of the power grid.

[0003] Connecting wind farms in series to the grid is one of the main forms of grid topology for large-scale renewable energy bases. Traditional wind farm reactive power and voltage control devices only focus on the reactive power of the controlled wind farm's own grid connection voltage. After receiving reactive power and voltage commands from the dispatch master station, they coordinate the reactive power equipment within the station to achieve reactive power and voltage tracking control at the grid connection point. Because each wind farm independently regulates its reactive power and traditional reactive power and voltage control strategies lack consideration for the reactive power regulation of other renewable energy stations in the series topology, it is difficult to effectively suppress grid voltage fluctuations. This can even cause reactive power to circulate among the series-connected wind farms, leading to grid voltage fluctuations and increased losses at each wind farm. Summary of the Invention

[0004] The main objective of this invention is to provide a reactive power and voltage control method and device based on a series-connected wind farm, so as to coordinate the reactive power equipment inside the wind farm, suppress the reactive power circulation that may occur in the series-connected wind farm, and improve the reactive power and voltage safety operation level of the wind farm.

[0005] To achieve the above objectives, embodiments of the present invention provide a reactive power and voltage control method based on a series-connected wind farm, comprising:

[0006] The total reactive power is determined based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value.

[0007] The reactive power regulation value and reactive power compensation regulation value of the wind turbine are determined based on the reactive power regulation value, reactive power compensation regulation value and total reactive power of the wind turbine.

[0008] Based on the reactive power regulation power of the wind turbine, a reactive power regulation command is sent to the wind turbine unit so that the wind turbine unit can adjust the reactive power according to the reactive power regulation command. Based on the reactive power compensation regulation power, a reactive power compensation command is sent to the reactive power compensation device so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation regulation command.

[0009] In one embodiment, determining the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value includes:

[0010] The reactive voltage sensitivity coefficient is determined based on the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time.

[0011] The total reactive power is determined based on the reactive voltage sensitivity coefficient and the current voltage deviation value.

[0012] In one embodiment, the grid connection point data at the previous adjustment time includes the grid connection point voltage and the grid connection point reactive power at the previous adjustment time, and the grid connection point data at the current adjustment time includes the grid connection point voltage and the grid connection point reactive power at the current adjustment time.

[0013] The reactive power sensitivity coefficient is determined based on the grid connection point data at the previous adjustment time and the current adjustment time, including:

[0014] The first sensitivity coefficient is determined based on the grid connection point voltage at the previous adjustment time and the grid connection point voltage at the current adjustment time.

[0015] The second sensitivity coefficient is determined based on the grid connection point voltage at the previous adjustment time, the grid connection point voltage at the current adjustment time, the reactive power at the grid connection point at the previous adjustment time, and the reactive power at the grid connection point at the current adjustment time.

[0016] The reactive voltage sensitivity coefficient is determined based on the first sensitivity coefficient and the second sensitivity coefficient.

[0017] In one embodiment, it further includes:

[0018] When the adjusted voltage deviation, the adjusted reactive power of the wind turbine, and the adjusted reactive power of the reactive power compensation device meet the first preset condition, a reactive power compensation optimization command is sent to the reactive power compensation device according to the reactive power compensation adjustment power so that the reactive power compensation device can optimize and adjust the reactive power according to the reactive power compensation optimization command.

[0019] When the optimized voltage deviation value and the optimized reactive power of the reactive power compensation device meet the second preset condition, the current voltage deviation value is replaced with the optimized voltage deviation value, and the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time are reacquired before corresponding iterative adjustment is performed.

[0020] This invention also provides a reactive power and voltage control device based on a series-connected wind farm, comprising:

[0021] The total reactive power determination module is used to determine the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value.

[0022] The reactive power regulation module is used to determine the reactive power regulation power and reactive power compensation regulation power of the wind turbine based on the reactive power regulation value, reactive power compensation regulation value and the total reactive power of the wind turbine.

[0023] The sending module is used to send a reactive power adjustment command from the wind turbine to the wind turbine unit according to the reactive power adjustment power of the wind turbine, so that the wind turbine unit can adjust the reactive power according to the reactive power adjustment command. It also sends a reactive power compensation adjustment command to the reactive power compensation device according to the reactive power compensation adjustment power, so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation adjustment command.

[0024] In one embodiment, the total reactive power determination module includes:

[0025] The reactive voltage sensitivity coefficient unit is used to determine the reactive voltage sensitivity coefficient based on the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time.

[0026] The total reactive power determination unit is used to determine the total reactive power based on the reactive voltage sensitivity coefficient and the current voltage deviation value.

[0027] In one embodiment, the grid connection point data at the previous adjustment time includes the grid connection point voltage and the grid connection point reactive power at the previous adjustment time, and the grid connection point data at the current adjustment time includes the grid connection point voltage and the grid connection point reactive power at the current adjustment time.

[0028] The reactive voltage sensitivity coefficient unit includes:

[0029] The first sensitivity coefficient subunit is used to determine the first sensitivity coefficient based on the grid connection point voltage at the previous adjustment time and the grid connection point voltage at the current adjustment time.

[0030] The second sensitivity coefficient subunit is used to determine the second sensitivity coefficient based on the grid connection point voltage at the previous adjustment time, the grid connection point voltage at the current adjustment time, the reactive power at the grid connection point at the previous adjustment time, and the reactive power at the grid connection point at the current adjustment time.

[0031] The reactive voltage sensitivity coefficient subunit is used to determine the reactive voltage sensitivity coefficient based on the first sensitivity coefficient and the second sensitivity coefficient.

[0032] In one embodiment, it further includes:

[0033] The optimization and adjustment module is used to send a reactive power compensation optimization command to the reactive power compensation device according to the reactive power compensation adjustment power when the adjusted voltage deviation value, the adjusted reactive power of the wind turbine and the adjusted reactive power of the reactive power compensation device meet the first preset condition, so that the reactive power compensation device can perform reactive power optimization adjustment according to the reactive power compensation optimization command.

[0034] The iterative adjustment module is used to replace the current voltage deviation value with the optimized voltage deviation value and the optimized reactive power of the reactive power compensation device when the optimized voltage deviation value and the optimized reactive power of the reactive power compensation device meet the second preset condition, and then perform corresponding iterative adjustment after re-acquiring the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time.

[0035] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of the reactive voltage control method based on a series-connected wind farm.

[0036] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the reactive voltage control method based on a series-connected wind farm.

[0037] This invention also provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the reactive voltage control method based on a series-connected wind farm.

[0038] The reactive power and voltage control method and device based on series-connected wind farms in this invention first determine the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value. Then, based on the reactive power adjustment value of the wind turbine, the reactive power compensation adjustment value, and the total reactive power, the reactive power adjustment power and the reactive power compensation adjustment power of the wind turbine are determined, and corresponding instructions are sent to adjust the reactive power. This can coordinate the reactive power equipment within the wind farm, suppress reactive power circulation that may occur in the series-connected wind farm, and improve the reactive power and voltage safety operation level of the wind farm. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart of the reactive voltage control method based on a series-connected wind farm in an embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of a reactive voltage control method based on a series-connected wind farm in another embodiment of the present invention;

[0042] Figure 3 This is a flowchart of S101 in an embodiment of the present invention;

[0043] Figure 4 This is a flowchart of S201 in an embodiment of the present invention;

[0044] Figure 5 This is a structural block diagram of the reactive voltage control device based on a series-connected wind farm in an embodiment of the present invention;

[0045] Figure 6 This is a structural block diagram of the computer device in an embodiment of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Those skilled in the art will recognize that embodiments of the present invention can be implemented as a system, apparatus, device, method, or computer program product. Therefore, this disclosure can be specifically implemented in the following forms: entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software.

[0048] Given that existing technologies struggle to effectively suppress grid voltage fluctuations, leading to reactive power circulating between connected wind farms, grid voltage oscillations, and increased losses at each wind farm, this invention provides a reactive power and voltage control method and apparatus based on connected wind farms. This method utilizes a specific algorithm to monitor reactive power and voltage tracking at the wind farm's grid connection point, thereby coordinating reactive power equipment within the wind farm and ultimately suppressing potential reactive power circulation in connected wind farms. The method offers more comprehensive data collection and more significant tracking results. The invention will be described in detail below with reference to the accompanying drawings.

[0049] Figure 1 This is a flowchart of a reactive voltage control method based on a series-connected wind farm in an embodiment of the present invention. Figure 2 This is a schematic diagram of a reactive power and voltage control method based on a series-connected wind farm, according to another embodiment of the present invention. Figures 1-2 As shown, the reactive power and voltage control method based on series-connected wind farms includes:

[0050] S101: Determine the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value.

[0051] The grid connection point data at the previous adjustment time includes the grid connection point voltage and reactive power at the previous adjustment time, while the grid connection point data at the current adjustment time includes the grid connection point voltage and reactive power at the current adjustment time.

[0052] The current voltage deviation value ΔV is the command voltage V issued by the dispatch terminal. ref The difference between the grid connection point voltage U2 and the voltage at the current adjustment time, ΔV = V ref -U2.

[0053] Figure 3 This is a flowchart of S101 in an embodiment of the present invention. Figure 3 As shown, S101 includes:

[0054] S201: Determine the reactive voltage sensitivity coefficient based on the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time.

[0055] Figure 4 This is a flowchart of S201 in an embodiment of the present invention. For example... Figure 4 As shown, S201 includes:

[0056] S301: Determine the first sensitivity coefficient based on the grid connection point voltage at the previous adjustment time and the grid connection point voltage at the current adjustment time.

[0057] In practical implementation, the first sensitivity coefficient can be determined using the following formula:

[0058] X1 = U1 - U2;

[0059] Where U1 is the grid connection point voltage at the previous adjustment time, U2 is the grid connection point voltage at the current adjustment time, and X1 is the first sensitivity coefficient.

[0060] S302: Determine the second sensitivity coefficient based on the grid connection point voltage at the previous adjustment time, the grid connection point voltage at the current adjustment time, the reactive power at the grid connection point at the previous adjustment time, and the reactive power at the grid connection point at the current adjustment time.

[0061] In practical implementation, the second sensitivity coefficient can be determined using the following formula:

[0062] X2 = Q1 / U1 - Q2 / U2;

[0063] Where X2 is the second sensitivity coefficient, Q1 is the reactive power at the grid connection point at the previous adjustment time, and Q2 is the reactive power at the grid connection point at the current adjustment time.

[0064] S303: Determine the reactive voltage sensitivity coefficient based on the first sensitivity coefficient and the second sensitivity coefficient.

[0065] In practical implementation, the reactive voltage sensitivity coefficient can be determined using the following formula:

[0066] X = X1 / X2;

[0067] Where X is the reactive voltage sensitivity coefficient.

[0068] S202: Determine the total reactive power based on the reactive voltage sensitivity coefficient and the current voltage deviation value.

[0069] In practical implementation, the total reactive power can be determined using the following formula:

[0070] ΔQ=ΔV / X;

[0071] Where ΔQ is the total reactive power and ΔV is the current voltage deviation.

[0072] S102: Determine the reactive power regulation power and reactive power compensation regulation power of the wind turbine based on the reactive power regulation value, reactive power compensation regulation value and total reactive power of the wind turbine.

[0073] Among them, the reactive power adjustment value of the wind turbine is the difference between the rated reactive power of the wind turbine and the current reactive power of the wind turbine, and the reactive power compensation adjustment value is the difference between the rated reactive power of the reactive power compensation device and the current reactive power of the reactive power compensation device.

[0074] In practical implementation, the reactive power regulation power of the fan can be determined using the following formula:

[0075]

[0076] The reactive power compensation adjustment power is determined by the following formula:

[0077]

[0078] Wherein, ΔQ1 is the reactive power regulation power of the wind turbine, ΔQ2 is the reactive power compensation regulation power, Qken is the reactive power regulation value of the wind turbine, and Qksvg is the reactive power compensation regulation value.

[0079] S103: Sends a reactive power adjustment command to the wind turbine unit according to the reactive power adjustment power of the wind turbine, so that the wind turbine unit can adjust the reactive power according to the reactive power adjustment command. Sends a reactive power compensation adjustment command to the reactive power compensation device according to the reactive power compensation adjustment power, so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation adjustment command.

[0080] After executing S103, the following is also included:

[0081] 1. When the adjusted voltage deviation, the adjusted reactive power of the wind turbine, and the adjusted reactive power of the reactive power compensation device meet the first preset condition, a reactive power compensation optimization command is sent to the reactive power compensation device according to the reactive power compensation adjustment power so that the reactive power compensation device can optimize and adjust the reactive power according to the reactive power compensation optimization command.

[0082] The first preset condition is the adjusted voltage deviation value (command voltage V). ref The absolute value of the difference between the adjusted grid connection point voltage and the adjusted voltage is less than or equal to the preset voltage threshold (i.e., within the target dead zone, the preset voltage threshold can be 0.5KV), and the adjusted reactive power of the wind turbine is greater than the preset percentage (e.g., 30%) of the rated reactive power of the wind turbine, and the adjusted reactive power of the reactive compensation device is greater than the preset percentage (e.g., 30%) of the rated reactive power of the reactive compensation device.

[0083] In practice, the reactive power optimization power in the reactive power compensation optimization instruction is 90% of the reactive power compensation adjustment power, which is 0.9ΔQ2.

[0084] When the adjusted voltage deviation value (command voltage V) ref If the absolute value of the difference between the voltage and the adjusted grid connection point voltage is greater than the preset voltage threshold (i.e., outside the target dead zone range), return to S101 to readjust.

[0085] When the adjusted voltage deviation value (command voltage V) ref When the absolute value of the difference between the adjusted grid connection point voltage and the adjusted voltage is less than or equal to the preset voltage threshold (i.e., within the target dead zone range), and the adjusted reactive power of the wind turbine is less than or equal to a preset percentage (e.g., 30%) of the rated reactive power of the wind turbine, or the adjusted reactive power of the reactive compensation device is less than or equal to a preset percentage (e.g., 30%) of the rated reactive power of the reactive compensation device, the adjustment is stopped, and S101 is executed again after a preset number of adjustment cycles (e.g., 20 adjustment cycles).

[0086] 2. When the optimized voltage deviation value and the optimized reactive power of the reactive power compensation device meet the second preset condition, the current voltage deviation value is replaced with the optimized voltage deviation value, and the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time are reacquired before corresponding iterative adjustment is performed.

[0087] The second preset condition is the optimized voltage deviation value (command voltage V). ref The absolute value of the difference between the voltage at the grid connection point and the voltage after optimization is greater than the preset voltage threshold (i.e., outside the target dead zone range), or the reactive power of the reactive power compensation device after optimization is less than or equal to the preset percentage (e.g., 30%) of the rated reactive power of the reactive power compensation device.

[0088] When the second preset condition is met, return to S101, replace the current voltage deviation value in S101 with the optimized voltage deviation value, and reacquire the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time to re-adjust the reactive power.

[0089] When the second preset condition is not met, an optimization command is resent to the reactive power compensation device based on the optimized reactive power compensation power, so that the reactive power compensation device can optimize and adjust the reactive power according to the latest optimization command. In the second optimization, the reactive power in the optimization command is 90% of the optimized reactive power compensation power, which is 0.9 × 0.9 × ΔQ². The reactive power in each optimization command is 90% of the previous value, and this iterative adjustment continues until the second preset condition is met.

[0090] Figure 1 The reactive power and voltage control method based on a series-connected wind farm, as shown, can be executed by a computer. Figure 1 As shown in the flowchart, the reactive power and voltage control method based on series-connected wind farms in this embodiment of the invention first determines the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value. Then, based on the reactive power adjustment value of the wind turbine, the reactive power compensation adjustment value, and the total reactive power, it determines the reactive power adjustment power and reactive power compensation adjustment power of the wind turbine and sends corresponding instructions to adjust the reactive power. This can coordinate the reactive power equipment inside the wind farm, suppress the reactive power circulation that may occur in the series-connected wind farm, and improve the reactive power and voltage safety operation level of the wind farm.

[0091] The specific process of this invention embodiment is as follows:

[0092] 1. Determine the first sensitivity coefficient based on the grid connection point voltage at the previous adjustment time and the grid connection point voltage at the current adjustment time.

[0093] 2. Determine the second sensitivity coefficient based on the grid connection point voltage at the previous adjustment time, the grid connection point voltage at the current adjustment time, the reactive power at the grid connection point at the previous adjustment time, and the reactive power at the grid connection point at the current adjustment time.

[0094] 3. Determine the reactive voltage sensitivity coefficient based on the first sensitivity coefficient and the second sensitivity coefficient.

[0095] 4. Determine the total reactive power based on the reactive voltage sensitivity coefficient and the current voltage deviation value.

[0096] 5. Determine the reactive power regulation power and reactive power compensation regulation power of the wind turbine based on the reactive power regulation value, reactive power compensation regulation value and total reactive power of the wind turbine.

[0097] 6. Send a reactive power adjustment command to the wind turbine generator set according to the reactive power adjustment power of the wind turbine, so that the wind turbine generator set can adjust the reactive power according to the reactive power adjustment command. Send a reactive power compensation adjustment command to the reactive power compensation device according to the reactive power compensation adjustment power, so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation adjustment command.

[0098] 7. When the adjusted voltage deviation, the adjusted reactive power of the wind turbine, and the adjusted reactive power of the reactive power compensation device meet the first preset condition, a reactive power compensation optimization command is sent to the reactive power compensation device according to the reactive power compensation adjustment power so that the reactive power compensation device can optimize and adjust the reactive power according to the reactive power compensation optimization command.

[0099] 8. When the optimized voltage deviation value and the optimized reactive power of the reactive power compensation device meet the second preset condition, replace the current voltage deviation value with the optimized voltage deviation value, reacquire the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time, and return to step 1 to perform the corresponding iterative adjustment.

[0100] In summary, this invention simultaneously collects reactive voltage and reactive power signals at the grid connection point of the wind farm, reactive voltage signals on the low-voltage side of the high-voltage main transformer of the wind farm, and reactive voltage signals at the ports of each wind turbine and dynamic reactive power compensation device. This enables comprehensive monitoring of the wind farm and allows for more rational distribution of reactive power within the wind farm through reactive voltage monitoring at each node, thus preventing the occurrence of reactive current circulation.

[0101] In summary, the reactive power and voltage control method based on series-connected wind farms provided by the embodiments of the present invention has the following beneficial effects:

[0102] (1) It integrates reactive voltage control strategies and reactive circulating current suppression methods for series wind farms, which can meet the reactive voltage control requirements of various types of wind farms.

[0103] (2) It can suppress the occurrence of wind farm circulation;

[0104] (3) Realize rapid reactive voltage tracking control at the grid connection point of the wind farm, suppress reactive circulating current inside the wind farm, and make reactive power distribution more reasonable.

[0105] Based on the same inventive concept, this invention also provides a reactive voltage control device based on a series-connected wind farm. Since the principle of this device in solving the problem is similar to that of the reactive voltage control method based on a series-connected wind farm, the implementation of this device can refer to the implementation of the method, and the repeated parts will not be described again.

[0106] Figure 5 This is a structural block diagram of a reactive power and voltage control device based on a series-connected wind farm, as described in an embodiment of the present invention. Figure 5As shown, the reactive power and voltage control device based on a series-connected wind farm includes:

[0107] The total reactive power determination module is used to determine the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value.

[0108] The reactive power regulation module is used to determine the reactive power regulation power and reactive power compensation regulation power of the wind turbine based on the reactive power regulation value, reactive power compensation regulation value and the total reactive power of the wind turbine.

[0109] The sending module is used to send a reactive power adjustment command from the wind turbine to the wind turbine unit according to the reactive power adjustment power of the wind turbine, so that the wind turbine unit can adjust the reactive power according to the reactive power adjustment command. It also sends a reactive power compensation adjustment command to the reactive power compensation device according to the reactive power compensation adjustment power, so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation adjustment command.

[0110] In one embodiment, the total reactive power determination module includes:

[0111] The reactive voltage sensitivity coefficient unit is used to determine the reactive voltage sensitivity coefficient based on the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time.

[0112] The total reactive power determination unit is used to determine the total reactive power based on the reactive voltage sensitivity coefficient and the current voltage deviation value.

[0113] In one embodiment, the grid connection point data at the previous adjustment time includes the grid connection point voltage and the grid connection point reactive power at the previous adjustment time, and the grid connection point data at the current adjustment time includes the grid connection point voltage and the grid connection point reactive power at the current adjustment time.

[0114] The reactive voltage sensitivity coefficient unit includes:

[0115] The first sensitivity coefficient subunit is used to determine the first sensitivity coefficient based on the grid connection point voltage at the previous adjustment time and the grid connection point voltage at the current adjustment time.

[0116] The second sensitivity coefficient subunit is used to determine the second sensitivity coefficient based on the grid connection point voltage at the previous adjustment time, the grid connection point voltage at the current adjustment time, the reactive power at the grid connection point at the previous adjustment time, and the reactive power at the grid connection point at the current adjustment time.

[0117] The reactive voltage sensitivity coefficient subunit is used to determine the reactive voltage sensitivity coefficient based on the first sensitivity coefficient and the second sensitivity coefficient.

[0118] In one embodiment, it further includes:

[0119] The optimization and adjustment module is used to send a reactive power compensation optimization command to the reactive power compensation device according to the reactive power compensation adjustment power when the adjusted voltage deviation value, the adjusted reactive power of the wind turbine and the adjusted reactive power of the reactive power compensation device meet the first preset condition, so that the reactive power compensation device can perform reactive power optimization adjustment according to the reactive power compensation optimization command.

[0120] The iterative adjustment module is used to replace the current voltage deviation value with the optimized voltage deviation value and the optimized reactive power of the reactive power compensation device when the optimized voltage deviation value and the optimized reactive power of the reactive power compensation device meet the second preset condition, and then perform corresponding iterative adjustment after re-acquiring the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time.

[0121] In summary, the reactive power and voltage control device based on a series-connected wind farm in this embodiment of the invention first determines the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value. Then, it determines the reactive power adjustment power and reactive power compensation adjustment power of the wind turbine based on the reactive power adjustment value, the reactive power compensation adjustment value, and the total reactive power, and sends corresponding instructions to adjust the reactive power. This can coordinate the reactive power equipment within the wind farm, suppress reactive power circulation that may occur in the series-connected wind farm, and improve the reactive power and voltage safety operation level of the wind farm.

[0122] The present invention also provides a specific implementation of a computer device capable of implementing all the steps in the reactive voltage control method based on series wind farms described in the above embodiments. Figure 6 This is a structural block diagram of the computer device in an embodiment of the present invention, see below. Figure 6 The computer equipment specifically includes the following:

[0123] Processor 601 and memory 602.

[0124] The processor 601 is used to call the computer program in the memory 602. When the processor executes the computer program, it implements all the steps in the reactive voltage control method based on series-connected wind farms in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0125] The total reactive power is determined based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value.

[0126] The reactive power regulation value and reactive power compensation regulation value of the wind turbine are determined based on the reactive power regulation value, reactive power compensation regulation value and total reactive power of the wind turbine.

[0127] Based on the reactive power regulation power of the wind turbine, a reactive power regulation command is sent to the wind turbine unit so that the wind turbine unit can adjust the reactive power according to the reactive power regulation command. Based on the reactive power compensation regulation power, a reactive power compensation command is sent to the reactive power compensation device so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation regulation command.

[0128] In summary, the computer equipment in this embodiment of the invention first determines the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value. Then, it determines the reactive power adjustment power and reactive power compensation adjustment power of the wind turbine based on the reactive power adjustment value, the reactive power compensation adjustment value, and the total reactive power, and sends corresponding instructions to adjust the reactive power. This can coordinate the reactive power equipment within the wind farm, suppress reactive circulating currents that may occur in the series-connected wind farm, and improve the reactive voltage safety operation level of the wind farm.

[0129] This invention also provides a computer-readable storage medium capable of implementing all steps of the reactive power and voltage control method based on a series-connected wind farm in the above embodiments. The computer-readable storage medium stores a computer program that, when executed by a processor, implements all steps of the reactive power and voltage control method based on a series-connected wind farm in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0130] The total reactive power is determined based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value.

[0131] The reactive power regulation value and reactive power compensation regulation value of the wind turbine are determined based on the reactive power regulation value, reactive power compensation regulation value and total reactive power of the wind turbine.

[0132] Based on the reactive power regulation power of the wind turbine, a reactive power regulation command is sent to the wind turbine unit so that the wind turbine unit can adjust the reactive power according to the reactive power regulation command. Based on the reactive power compensation regulation power, a reactive power compensation command is sent to the reactive power compensation device so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation regulation command.

[0133] In summary, the computer-readable storage medium of this invention first determines the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value. Then, it determines the reactive power adjustment power and reactive power compensation adjustment power of the wind turbine based on the reactive power adjustment value, the reactive power compensation adjustment value, and the total reactive power, and sends corresponding instructions to adjust the reactive power. This can coordinate the reactive power equipment within the wind farm, suppress reactive circulating currents that may occur in the series-connected wind farm, and improve the reactive voltage safety operation level of the wind farm.

[0134] This invention also provides a computer program product capable of implementing all steps of the reactive power and voltage control method based on series-connected wind farms in the above embodiments. The computer program product includes a computer program / instruction, which, when executed by a processor, implements all steps of the reactive power and voltage control method based on series-connected wind farms in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0135] The total reactive power is determined based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value.

[0136] The reactive power regulation value and reactive power compensation regulation value of the wind turbine are determined based on the reactive power regulation value, reactive power compensation regulation value and total reactive power of the wind turbine.

[0137] Based on the reactive power regulation power of the wind turbine, a reactive power regulation command is sent to the wind turbine unit so that the wind turbine unit can adjust the reactive power according to the reactive power regulation command. Based on the reactive power compensation regulation power, a reactive power compensation command is sent to the reactive power compensation device so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation regulation command.

[0138] In summary, the computer program product of this invention first determines the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value. Then, it determines the reactive power adjustment power and reactive power compensation adjustment power of the wind turbine based on the reactive power adjustment value, the reactive power compensation adjustment value, and the total reactive power, and sends corresponding instructions to adjust the reactive power. This can coordinate the reactive power equipment within the wind farm, suppress reactive circulating currents that may occur in the series-connected wind farm, and improve the reactive voltage safety operation level of the wind farm.

[0139] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0140] Those skilled in the art will also understand that the various illustrative logical blocks, units, and steps listed in the embodiments of the present invention can be implemented by electronic hardware, computer software, or a combination of both. To clearly demonstrate the interchangeability of hardware and software, the functions of the various illustrative components, units, and steps described above have been generally described. Whether such functionality is implemented through hardware or software depends on the specific application and the overall system design requirements. Those skilled in the art can implement the described functions using various methods for each specific application, but such implementation should not be construed as exceeding the scope of protection of the embodiments of the present invention.

[0141] The various illustrative logic blocks, units, or devices described in the embodiments of this invention can be implemented or operate the described functions using a general-purpose processor, digital signal processor, application-specific integrated circuit (ASIC), field-programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor; alternatively, it can be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented using a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0142] The steps of the methods or algorithms described in the embodiments of this invention can be directly embedded in hardware, a software module executed by a processor, or a combination of both. The software module can be stored in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from and write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and storage medium can be housed in an ASIC, which can be housed in a user terminal. Optionally, the processor and storage medium can also be housed in different components of the user terminal.

[0143] In one or more exemplary designs, the functions described in the embodiments of the present invention can be implemented in hardware, software, firmware, or any combination of these three. If implemented in software, these functions can be stored on a computer-readable medium or transmitted on a computer-readable medium in the form of one or more instructions or code. Computer-readable media include computer storage media and communication media that facilitate the transfer of computer programs from one place to another. Storage media can be any available media that can be accessed by a general-purpose or special-purpose computer. For example, such computer-readable media can include, but is not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store program code in the form of instructions or data structures and other forms that can be read by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Furthermore, any connection can be suitably defined as a computer-readable medium, for example, if the software is transmitted from a website, server or other remote resource via a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wirelessly, such as infrared, wireless and microwave, it is also included in the defined computer-readable medium. The disks and discs mentioned include compressed disks, laser discs, optical discs, DVDs, floppy disks, and Blu-ray discs. Disks typically copy data magnetically, while disks typically copy data optically using lasers. Combinations of the above can also be contained in computer-readable media.

Claims

1. A reactive power and voltage control method based on a series-connected wind farm, characterized in that, include: The total reactive power is determined based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value. The reactive power adjustment value and reactive power compensation adjustment value of the wind turbine are determined based on the reactive power adjustment value, reactive power compensation adjustment value and the total reactive power of the wind turbine. According to the reactive power regulation power of the wind turbine, a reactive power regulation command is sent to the wind turbine unit so that the wind turbine unit can adjust the reactive power according to the reactive power regulation command. According to the reactive power compensation regulation power, a reactive power compensation command is sent to the reactive power compensation device so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation regulation command. The determination of total reactive power based on grid connection point data at the previous adjustment time, grid connection point data at the current adjustment time, and current voltage deviation value includes: The reactive voltage sensitivity coefficient is determined based on the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time. The total reactive power is determined based on the reactive voltage sensitivity coefficient and the current voltage deviation value; The grid connection point data at the previous adjustment time includes the grid connection point voltage and reactive power at the previous adjustment time, and the grid connection point data at the current adjustment time includes the grid connection point voltage and reactive power at the current adjustment time. The reactive power sensitivity coefficient is determined based on the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time, including: The first sensitivity coefficient is determined based on the grid connection point voltage at the previous adjustment time and the grid connection point voltage at the current adjustment time. The second sensitivity coefficient is determined based on the grid connection point voltage at the previous adjustment time, the grid connection point voltage at the current adjustment time, the reactive power at the grid connection point at the previous adjustment time, and the reactive power at the grid connection point at the current adjustment time. The reactive voltage sensitivity coefficient is determined based on the first sensitivity coefficient and the second sensitivity coefficient.

2. The reactive power and voltage control method based on a series-connected wind farm according to claim 1, characterized in that, Also includes: When the adjusted voltage deviation value, the adjusted reactive power of the wind turbine, and the adjusted reactive power of the reactive power compensation device meet the first preset condition, a reactive power compensation optimization command is sent to the reactive power compensation device according to the reactive power compensation adjustment power so that the reactive power compensation device can optimize and adjust the reactive power according to the reactive power compensation optimization command. When the optimized voltage deviation value and the optimized reactive power of the reactive power compensation device meet the second preset condition, the current voltage deviation value is replaced with the optimized voltage deviation value, and the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time are reacquired before corresponding iterative adjustment is performed.

3. A reactive power and voltage control device based on a series-connected wind farm, characterized in that, include: The total reactive power determination module is used to determine the total reactive power based on the grid connection point data at the previous adjustment time, the grid connection point data at the current adjustment time, and the current voltage deviation value. The reactive power regulation module is used to determine the reactive power regulation power and reactive power compensation regulation power of the wind turbine based on the reactive power regulation value, reactive power compensation regulation value and the total reactive power of the wind turbine. The sending module is used to send a reactive power adjustment command from the wind turbine to the wind turbine generator set according to the reactive power adjustment power of the wind turbine, so that the wind turbine generator set can adjust the reactive power according to the reactive power adjustment command; and to send a reactive power compensation adjustment command to the reactive power compensation device according to the reactive power compensation adjustment power, so that the reactive power compensation device can adjust the reactive power according to the reactive power compensation adjustment command. The total reactive power determination module includes: The reactive voltage sensitivity coefficient unit is used to determine the reactive voltage sensitivity coefficient based on the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time. The total reactive power determination unit is used to determine the total reactive power based on the reactive voltage sensitivity coefficient and the current voltage deviation value. The grid connection point data at the previous adjustment time includes the grid connection point voltage and reactive power at the previous adjustment time, and the grid connection point data at the current adjustment time includes the grid connection point voltage and reactive power at the current adjustment time. The reactive voltage sensitivity coefficient unit includes: The first sensitivity coefficient subunit is used to determine the first sensitivity coefficient based on the grid connection point voltage at the previous adjustment time and the grid connection point voltage at the current adjustment time. The second sensitivity coefficient subunit is used to determine the second sensitivity coefficient based on the grid connection point voltage at the previous adjustment time, the grid connection point voltage at the current adjustment time, the reactive power at the grid connection point at the previous adjustment time, and the reactive power at the grid connection point at the current adjustment time. The reactive voltage sensitivity coefficient subunit is used to determine the reactive voltage sensitivity coefficient based on the first sensitivity coefficient and the second sensitivity coefficient.

4. The reactive power and voltage control device based on a series-connected wind farm according to claim 3, characterized in that, Also includes: The optimization and adjustment module is used to send a reactive power compensation optimization command to the reactive power compensation device according to the reactive power compensation adjustment power when the adjusted voltage deviation value, the adjusted reactive power of the wind turbine and the adjusted reactive power of the reactive power compensation device meet the first preset condition, so that the reactive power compensation device can perform reactive power optimization adjustment according to the reactive power compensation optimization command. The iterative adjustment module is used to replace the current voltage deviation value with the optimized voltage deviation value and the optimized reactive power of the reactive power compensation device when the optimized voltage deviation value and the optimized reactive power compensation device meet the second preset condition, and then perform corresponding iterative adjustment after re-acquiring the grid connection point data at the previous adjustment time and the grid connection point data at the current adjustment time.

5. A computer device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the reactive voltage control method based on a series-connected wind farm as described in claim 1 or 2.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the reactive voltage control method based on a series-connected wind farm as described in claim 1 or 2.

7. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the reactive voltage control method based on a series-connected wind farm as described in claim 1 or 2.

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