A composite high-voltage reactive power compensation method and system

Abstract

This invention relates to the field of reactive power compensation technology, specifically to a composite high-voltage reactive power compensation method and system. First, a detection module acquires the power parameters at the output side of the transformer and sends them to a calculation module. These output-side power parameters are the power parameters of the user node. The calculation module determines the corresponding reactive power compensation demand based on the output-side power parameters. When the reactive power compensation demand is less than a first preset demand, it indicates a low load demand at the user node, so only thyristor-switched capacitors are activated, providing accurate compensation. When the reactive power compensation demand is greater than or equal to the first preset demand, it indicates a high load demand at the user node, and high-voltage filtering and reactive power compensation devices are activated, with at least one branch of the high-voltage device activated to achieve large-capacity compensation.

Description

Technical Field

[0001] This invention relates to the field of reactive power compensation technology, specifically to a composite high-voltage reactive power compensation method and system. Background Technology

[0002] Traditional distributed power management methods centrally process data at the distribution network master station. Due to the frequent changes in the access status of power electronic equipment in the distribution network, it is difficult to update the data on voltage deviation and reactive power compensation in the distribution network information system in a timely manner. As a result, the distribution network master station has difficulty in real-time control of distribution network harmonic suppression and reactive power compensation. Therefore, there is an urgent need for a technical solution that can perform reactive power compensation on the user side. Summary of the Invention

[0003] The main objective of this invention is to provide a composite high-voltage reactive power compensation method and system, aiming to solve the current urgent need for a technical solution that can perform reactive power compensation on the user side.

[0004] The technical solution proposed in this invention is as follows: A composite high-voltage reactive power compensation method is applied to a composite high-voltage reactive power compensation system. The system includes a detection module, a calculation module, a controller, and reactive power compensation equipment. The detection module and the controller are both communicatively connected to the calculation module. The controller is used to control the start and stop of the reactive power compensation equipment. The reactive power compensation equipment includes a thyristor-switched capacitor and a high-voltage filter and reactive power compensation device. The method includes: The detection module acquires the power parameters at the output side of the transformer and sends them to the calculation module. The user nodes are electrically connected to the output side of the transformer, and there are multiple user nodes. The calculation module determines the reactive power compensation requirement corresponding to the output side based on the power parameters on the output side. When the reactive power compensation demand on the output side is less than the first preset demand, the calculation module generates a first compensation instruction and sends it to the controller. The controller starts the thyristor switching capacitor to perform reactive power compensation on the output side based on the first compensation command. When the reactive power compensation demand on the output side is greater than or equal to the first preset demand, the calculation module generates a second compensation instruction and sends it to the controller. The controller activates the high-voltage filter and reactive power compensation device to perform reactive power compensation on the output side based on the second compensation command.

[0005] Preferably, the power parameters include active power and power factor angle; the calculation module determines the reactive power compensation requirement corresponding to the output side based on the power parameters on the output side, including: The calculation module obtains the average active power over a preset time period and the average power factor angle over a preset time period based on power parameters. The calculation module obtains the target power factor angle; The calculation module calculates the reactive power compensation requirement corresponding to the output side based on the average active power, the average power factor angle, and the target power factor angle.

[0006] Preferably, the calculation module calculates the reactive power compensation demand corresponding to the output side based on the average active power, the average power factor angle, and the target power factor angle using the following formula: (1), In the formula, The reactive power compensation requirement is expressed in kilovars. The active power is the average value, in kilowatts; The average power factor angle, The target power factor angle.

[0007] Preferably, the high-voltage filtering and reactive power compensation device includes multiple capacitors connected in parallel; the controller activates the high-voltage filtering and reactive power compensation device to perform reactive power compensation on the output side based on the second compensation command, including: The controller acquires the rated operating voltage and rated capacitance of each capacitor in the high-voltage filtering and reactive power compensation device. The controller acquires the current actual output voltage of the transformer detected by the detection module; The controller calculates and determines the actual reactive power capacity that each capacitor can provide based on the rated operating voltage and rated capacitance of each capacitor, as well as the actual output voltage. The controller controls the switching of each capacitor based on its actual reactive power capacity to perform reactive power compensation.

[0008] Preferably, the controller calculates the actual reactive power capacity that each capacitor can provide based on its rated operating voltage and rated capacitance, as well as the actual output voltage, using the following formula: (2), In the formula, The actual reactive power capacity that the capacitor can provide, expressed in kilovars; This refers to the rated capacitance of the capacitor, expressed in kilovars. This is the rated operating voltage of the capacitor, expressed in kilovolts. The actual output voltage is given in kilovolts.

[0009] Preferably, the controller controls the switching of each capacitor based on its actual reactive power capacity to perform reactive power compensation, including: If the first preset condition is met, the controller uses a cyclic switching method to control each capacitor to perform reactive power compensation. The first preset condition is that each capacitor can provide the same actual reactive power capacity. If the second preset condition is met, the controller uses a coded switching method to control each capacitor to perform reactive power compensation. The second preset condition is that the ratio between the actual reactive power capacity that each capacitor can provide is an integer.

[0010] Preferably, if the second preset condition is met, the controller uses a coded switching method to control each capacitor for reactive power compensation, and then further includes: If neither the first preset condition nor the second preset condition is met, the controller uses an optimal switching method to control each capacitor for reactive power compensation.

[0011] Preferably, if neither the first preset condition nor the second preset condition is met, the controller uses an optimal switching method to control each capacitor for reactive power compensation, including: When a capacitor needs to be connected, the controller obtains the reactive power compensation requirement on the output side. The controller marks the capacitors that are not currently in operation in the high-voltage filtering and reactive power compensation device as capacitors to be put into operation, and marks the capacitor with the largest actual reactive power capacity that can be provided among the capacitors to be put into operation but which is less than the reactive power compensation requirement as the first preferred capacitor. The controller controls the first preferred capacitor to be put into operation for reactive power compensation, and obtains the latest reactive power compensation demand on the output side after the reactive power compensation is completed. The controller removes the first preferred capacitor label from the capacitors that have already been put into service; The controller determines whether the latest reactive power compensation demand on the output side after reactive power compensation is completed is still greater than or equal to the first preset demand. If so, the controller marks the capacitors that are not currently in operation in the high-voltage filtering and reactive power compensation device as capacitors to be put into operation, and marks the capacitor with the largest actual reactive power capacity that can be provided among the capacitors to be put into operation and which is less than the reactive power compensation requirement as the first preferred capacitor, and then proceeds to the following steps. If not, the controller activates the thyristor to switch the capacitor to perform reactive power compensation on the output side.

[0012] Preferably, if neither the first preset condition nor the second preset condition is met, the controller uses an optimal switching method to control each capacitor for reactive power compensation, and then further includes: When it is necessary to disconnect the capacitor, the controller obtains the reactive power disconnection requirement on the output side; The controller marks the capacitors that are currently in operation in the high-voltage filter and reactive power compensation device as in operation capacitors, and marks the capacitor among the in operation capacitors that can provide the largest actual reactive power capacity that is less than the reactive power cut-off requirement as the second preferred capacitor. The controller controls the second preferred capacitor to be disconnected so that reactive power compensation is no longer performed, and obtains the latest reactive power disconnection requirement on the output side after the disconnection is completed. The controller removes the mark of the second preferred capacitor from the capacitor that has already been cut off; The controller determines whether the latest reactive power cut-off demand on the output side after the cut-off is completed is greater than the second preset demand. If so, the controller marks the capacitors currently in operation in the high-voltage filter and reactive power compensation device as in operation capacitors, and marks the capacitor with the largest actual reactive power capacity that can be provided among the in operation capacitors and which is less than the reactive power cut-off requirement as the second preferred capacitor, and then proceeds to the following steps. If not, the controller stops disconnecting the capacitor.

[0013] This invention also proposes a composite high-voltage reactive power compensation system, applying a composite high-voltage reactive power compensation method; the system includes a detection module, a calculation module, a controller, and reactive power compensation equipment; the detection module and the controller are both communicatively connected to the calculation module; the controller is used to control the start and stop of the reactive power compensation equipment; the reactive power compensation equipment includes thyristor-switched capacitors and high-voltage filtering and reactive power compensation devices.

[0014] The above technical solution can achieve the following beneficial effects: The composite high-voltage reactive power compensation method proposed in this invention can solve the current problem of the urgent need for a technical solution that can perform reactive power compensation on the user side. This application first obtains the power parameters on the output side of the transformer through the detection module and sends them to the calculation module. The power parameters on the output side are the power parameters of the user node. The calculation module determines the reactive power compensation demand corresponding to the output side based on the power parameters on the output side. When the reactive power compensation demand corresponding to the output side is less than the first preset demand, it indicates that the user node has a small load demand. Therefore, only the thyristor-switched capacitor is put into operation. The thyristor-switched capacitor can provide accurate compensation. When the reactive power compensation demand corresponding to the output side is greater than or equal to the first preset demand, it indicates that the user node has a large load demand. The high-voltage filter and reactive power compensation device is put into operation. At least one branch of the high-voltage device is put into operation to achieve large-capacity compensation. Attached Figure Description

[0015] 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 or the prior art 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 the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating the first embodiment of a composite high-voltage reactive power compensation method proposed in this invention. Detailed Implementation

[0017] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0018] This invention proposes a composite high-voltage reactive power compensation method and system.

[0019] As attached Figure 1 As shown, in the first embodiment of the composite high-voltage reactive power compensation method proposed in this invention, the composite high-voltage reactive power compensation method is applied to a composite high-voltage reactive power compensation system; the system includes a detection module, a calculation module, a controller, and reactive power compensation equipment; the detection module and the controller are both communicatively connected to the calculation module; the controller is used to control the start and stop of the reactive power compensation equipment; the reactive power compensation equipment includes a thyristor-switched capacitor and a high-voltage filter and reactive power compensation device; this embodiment includes the following steps: Step S110: The detection module acquires the power parameters at the output side of the transformer and sends them to the calculation module. The user nodes are electrically connected to the output side of the transformer, and there are multiple user nodes.

[0020] Specifically, the detection module here includes voltage sensors, current sensors, and current transformers.

[0021] Step S120: The calculation module determines the reactive power compensation requirement corresponding to the output side based on the power parameters on the output side. Thyristor switching capacitors. Step S130: When the reactive power compensation demand corresponding to the output side is less than the first preset demand (e.g., 300 kvar), the calculation module generates a first compensation instruction and sends it to the controller.

[0022] Step S140: The controller starts the thyristor switching capacitor to perform reactive power compensation on the output side based on the first compensation command.

[0023] Specifically, a thyristor-switched capacitor (TSC) is a reactive power compensation device connected in parallel with the power grid. It consists of an anti-parallel thyristor valve, a capacitor bank, and a current-limiting reactor connected in series. When the reactive power compensation demand is less than the first preset demand, it is determined that the output side has a small load demand. Therefore, only the thyristor-switched capacitor is put into operation. The thyristor-switched capacitor can provide accurate compensation, and the step-up transformer transfers the compensation energy to the high-voltage side.

[0024] Step S150: When the reactive power compensation demand corresponding to the output side is greater than or equal to the first preset demand, the calculation module generates a second compensation instruction and sends it to the controller.

[0025] Step S160: The controller starts the high-voltage filter and reactive power compensation device to perform reactive power compensation on the output side based on the second compensation command.

[0026] Specifically, when the reactive power compensation demand on the output side is greater than or equal to the first preset demand, the output side is determined to be under heavy load, and the high-voltage filter and reactive power compensation device is activated. At least one branch of the high-voltage device is activated to achieve high-capacity compensation.

[0027] The composite high-voltage reactive power compensation method proposed in this invention can solve the current problem of the urgent need for a technical solution that can perform reactive power compensation on the user side. This application first obtains the power parameters on the output side of the transformer through the detection module and sends them to the calculation module. The power parameters on the output side are the power parameters of the user node. The calculation module determines the reactive power compensation demand corresponding to the output side based on the power parameters on the output side. When the reactive power compensation demand corresponding to the output side is less than the first preset demand, it indicates that the user node has a small load demand. Therefore, only the thyristor-switched capacitor is put into operation. The thyristor-switched capacitor can provide accurate compensation. When the reactive power compensation demand corresponding to the output side is greater than or equal to the first preset demand, it indicates that the user node has a large load demand. The high-voltage filter and reactive power compensation device is put into operation. At least one branch of the high-voltage device is put into operation to achieve large-capacity compensation.

[0028] In the second embodiment of the composite high-voltage reactive power compensation method proposed in this invention, based on the first embodiment, step S120 includes the following steps: Step S210: The calculation module obtains the average active power over a preset time period (e.g., 5 minutes) and the average power factor angle over a preset time period based on the power parameters.

[0029] Step S220: The calculation module obtains the target power factor angle.

[0030] Step S230: The calculation module calculates the reactive power compensation requirement corresponding to the output side based on the average active power, the average power factor angle, and the target power factor angle.

[0031] In the third embodiment of the composite high-voltage reactive power compensation method proposed in this invention, based on the second embodiment, the calculation module calculates the reactive power compensation demand corresponding to the output side based on the average active power, the average power factor angle, and the target power factor angle using the following formula: (1), In the formula, The reactive power compensation requirement is expressed in kilovars. The active power is the average value, in kilowatts; The average power factor angle, The target power factor angle (e.g., 18.26°).

[0032] This embodiment provides a specific formula for calculating the reactive power compensation requirement on the output side.

[0033] In the fourth embodiment of the composite high-voltage reactive power compensation method proposed in this invention, based on the first embodiment, the high-voltage filtering and reactive power compensation device includes multiple capacitors connected in parallel; step S160 includes the following steps: Step S410: The controller obtains the rated operating voltage and rated capacitance of each capacitor in the high-voltage filtering and reactive power compensation device.

[0034] Step S420: The controller acquires the current actual output voltage of the transformer detected by the detection module.

[0035] Step S430: The controller calculates and determines the actual reactive power capacity that each capacitor can provide based on the rated operating voltage and rated capacitance of each capacitor, as well as the actual output voltage.

[0036] Step S440: The controller controls the switching of each capacitor based on the actual reactive power capacity of each capacitor to perform reactive power compensation.

[0037] In the fifth embodiment of the composite high-voltage reactive power compensation method proposed in this invention, based on the fourth embodiment, the controller calculates the actual reactive power capacity that each capacitor can provide based on the rated operating voltage and rated capacitance of each capacitor, as well as the actual output voltage. The calculation formula is as follows: (2), In the formula, The actual reactive power capacity that the capacitor can provide, expressed in kilovars; This refers to the rated capacitance of the capacitor, expressed in kilovars. This is the rated operating voltage of the capacitor, expressed in kilovolts. The actual output voltage is given in kilovolts.

[0038] Specifically, the actual reactive power provided by a capacitor is proportional to the square of the voltage. This embodiment provides a specific formula for calculating the actual reactive power.

[0039] In the sixth embodiment of the composite high-voltage reactive power compensation method proposed in this invention, based on the fourth embodiment, step S440 includes the following steps: Step S610: If the first preset condition is met, the controller uses a cyclic switching method to control each capacitor to perform reactive power compensation, wherein the first preset condition is: the actual reactive power capacity that each capacitor can provide is the same.

[0040] Step S620: If the second preset condition is met, the controller uses a coding switching method to control each capacitor to perform reactive power compensation, wherein the second preset condition is: the ratio between the actual reactive power capacity that each capacitor can provide is an integer.

[0041] In the seventh embodiment of the composite high-voltage reactive power compensation method proposed in this invention, based on the sixth embodiment, after step S620, the following steps are further included: Step S710: If neither the first preset condition nor the second preset condition is met, the controller uses an optimal switching method to control each capacitor for reactive power compensation.

[0042] In the eighth embodiment of the composite high-voltage reactive power compensation method proposed in this invention, based on the seventh embodiment, step S710 includes the following steps: Step S810: When it is necessary to connect the capacitor, the controller obtains the reactive power compensation requirement on the output side.

[0043] Step S820: The controller marks the capacitors that are not currently in operation in the high-voltage filtering and reactive power compensation device as capacitors to be put into operation, and marks the capacitor with the largest actual reactive power capacity that can be provided among the capacitors to be put into operation and which is less than the reactive power compensation requirement as the first preferred capacitor.

[0044] Step S830: The controller controls the first preferred capacitor to be put into operation for reactive power compensation, and obtains the latest reactive power compensation demand on the output side after the reactive power compensation is completed.

[0045] Step S840: The controller removes the mark of the first preferred capacitor from the capacitors that have already been put into service; Step S850: The controller determines whether the latest reactive power compensation demand on the output side after reactive power compensation is completed is still greater than or equal to the first preset demand.

[0046] If so, proceed with step S820 and subsequent steps.

[0047] If not, step S860: The controller starts the thyristor to switch the capacitor to perform reactive power compensation on the output side.

[0048] Specifically, the technical solution of this embodiment allows for the sequential deployment of capacitors with larger actual reactive power capacities that are smaller than the reactive power compensation requirement. This prioritizes the use of larger capacity capacitors for compensation while still meeting the compensation demand. Consequently, while ensuring the required compensation power is met, the number of capacitors deployed is minimized, thus reducing the amount of operation required.

[0049] In the ninth embodiment of the composite high-voltage reactive power compensation method proposed in this invention, based on the seventh embodiment, if neither the first preset condition nor the second preset condition is satisfied, the controller uses an optimal switching method to control each capacitor to perform reactive power compensation, and then further includes the following steps: Step S910: When it is necessary to disconnect the capacitor, the controller obtains the reactive power disconnection requirement on the output side.

[0050] Step S920: The controller marks the capacitors currently in operation in the high-voltage filtering and reactive power compensation device as operational capacitors, and marks the capacitor among the operational capacitors that can provide the largest actual reactive power capacity that is less than the reactive power cut-off requirement as the second preferred capacitor.

[0051] Step S930: The controller controls the second preferred capacitor to be disconnected so that reactive power compensation is no longer performed, and obtains the latest reactive power disconnection requirement on the output side after the disconnection is completed.

[0052] Step S940: The controller removes the mark of the second preferred capacitor from the capacitor that has already been cut off; Step S950: The controller determines whether the latest reactive power cut-off demand on the output side after the cut-off is completed is greater than the second preset demand (e.g., 50 kvar).

[0053] If so, proceed to step S920 and subsequent steps.

[0054] If not, step S960: the controller stops disconnecting the capacitor.

[0055] Specifically, through the technical solution of this embodiment, capacitors with larger actual reactive capacity but smaller reactive power cut-off requirements can be cut off sequentially, thereby minimizing the number of capacitors cut off while ensuring the required reactive power cut-off, thus reducing the amount of operation.

[0056] This invention also proposes a composite high-voltage reactive power compensation system, applying a composite high-voltage reactive power compensation method; the system includes a detection module, a calculation module, a controller, and reactive power compensation equipment; the detection module and the controller are both communicatively connected to the calculation module; the controller is used to control the start and stop of the reactive power compensation equipment; the reactive power compensation equipment includes thyristor-switched capacitors and high-voltage filtering and reactive power compensation devices.

[0057] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0058] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A composite high-voltage reactive power compensation method, characterized in that, This system is applied to a composite high-voltage reactive power compensation system; the system includes a detection module, a calculation module, a controller, and reactive power compensation equipment; the detection module and the controller are both communicatively connected to the calculation module. The controller is used to control the start and stop of the reactive power compensation equipment; The reactive power compensation equipment includes thyristor-switched capacitors and high-voltage filtering and reactive power compensation devices; the method includes: The detection module acquires the power parameters at the output side of the transformer and sends them to the calculation module. The user nodes are electrically connected to the output side of the transformer, and there are multiple user nodes. The calculation module determines the reactive power compensation requirement corresponding to the output side based on the power parameters on the output side. When the reactive power compensation demand on the output side is less than the first preset demand, the calculation module generates a first compensation instruction and sends it to the controller. The controller starts the thyristor switching capacitor to perform reactive power compensation on the output side based on the first compensation command. When the reactive power compensation demand on the output side is greater than or equal to the first preset demand, the calculation module generates a second compensation instruction and sends it to the controller. The controller activates the high-voltage filter and reactive power compensation device to perform reactive power compensation on the output side based on the second compensation command.

2. The composite high-voltage reactive power compensation method according to claim 1, characterized in that, The electrical parameters include active power and power factor angle; The calculation module determines the reactive power compensation requirement corresponding to the output side based on the power parameters on the output side, including: The calculation module obtains the average active power over a preset time period and the average power factor angle over a preset time period based on power parameters. The calculation module obtains the target power factor angle; The calculation module calculates the reactive power compensation requirement corresponding to the output side based on the average active power, the average power factor angle, and the target power factor angle.

3. The composite high-voltage reactive power compensation method according to claim 2, characterized in that, The calculation module calculates the reactive power compensation demand corresponding to the output side based on the average active power, the average power factor angle, and the target power factor angle using the following formula: （1）， In the formula, The reactive power compensation requirement is expressed in kilovars. The active power is the average value, in kilowatts; The average power factor angle, The target power factor angle.

4. The composite high-voltage reactive power compensation method according to claim 1, characterized in that, The high-voltage filtering and reactive power compensation device includes multiple capacitors connected in parallel. The controller, based on the second compensation command, activates the high-voltage filter and reactive power compensation device to perform reactive power compensation on the output side, including: The controller acquires the rated operating voltage and rated capacitance of each capacitor in the high-voltage filtering and reactive power compensation device. The controller acquires the current actual output voltage of the transformer detected by the detection module; The controller calculates and determines the actual reactive power capacity that each capacitor can provide based on the rated operating voltage and rated capacitance of each capacitor, as well as the actual output voltage. The controller controls the switching of each capacitor based on its actual reactive power capacity to perform reactive power compensation.

5. The composite high-voltage reactive power compensation method according to claim 4, characterized in that, The controller calculates the actual reactive power capacity that each capacitor can provide based on its rated operating voltage and rated capacitance, as well as the actual output voltage. The formula is as follows: （2）， In the formula, The actual reactive power capacity that the capacitor can provide, expressed in kilovars; This refers to the rated capacitance of the capacitor, expressed in kilovars. This is the rated operating voltage of the capacitor, expressed in kilovolts. The actual output voltage is given, in kilovolts.

6. The composite high-voltage reactive power compensation method according to claim 4, characterized in that, The controller controls the switching of each capacitor based on its actual reactive power capacity to perform reactive power compensation, including: If the first preset condition is met, the controller uses a cyclic switching method to control each capacitor to perform reactive power compensation. The first preset condition is that each capacitor can provide the same actual reactive power capacity. If the second preset condition is met, the controller uses a coded switching method to control each capacitor to perform reactive power compensation. The second preset condition is that the ratio between the actual reactive power capacity that each capacitor can provide is an integer.

7. The composite high-voltage reactive power compensation method according to claim 6, characterized in that, If the second preset condition is met, the controller uses a coded switching method to control each capacitor for reactive power compensation, and then further includes: If neither the first preset condition nor the second preset condition is met, the controller uses an optimal switching method to control each capacitor for reactive power compensation.

8. The composite high-voltage reactive power compensation method according to claim 7, characterized in that, If neither the first preset condition nor the second preset condition is met, the controller uses an optimal switching method to control each capacitor for reactive power compensation, including: When a capacitor needs to be connected, the controller obtains the reactive power compensation requirement on the output side. The controller marks the capacitors that are not currently in operation in the high-voltage filtering and reactive power compensation device as capacitors to be put into operation, and marks the capacitor with the largest actual reactive power capacity that can be provided among the capacitors to be put into operation but which is less than the reactive power compensation requirement as the first preferred capacitor. The controller controls the first preferred capacitor to be put into operation for reactive power compensation, and obtains the latest reactive power compensation demand on the output side after the reactive power compensation is completed. The controller removes the first preferred capacitor label from the capacitors that have already been put into service; The controller determines whether the latest reactive power compensation demand on the output side after reactive power compensation is completed is still greater than or equal to the first preset demand. If so, the controller marks the capacitors that are not currently in operation in the high-voltage filter and reactive power compensation device as capacitors to be put into operation, and marks the capacitor with the largest actual reactive power capacity that can be provided among the capacitors to be put into operation and which is less than the reactive power compensation requirement as the first preferred capacitor, and then proceeds to the following steps. If not, the controller activates the thyristor to switch the capacitor to perform reactive power compensation on the output side.

9. A composite high-voltage reactive power compensation method according to claim 7, characterized in that, If neither the first preset condition nor the second preset condition is met, the controller uses an optimal switching method to control each capacitor for reactive power compensation, and then further includes: When it is necessary to disconnect the capacitor, the controller obtains the reactive power disconnection requirement on the output side; The controller marks the capacitors currently in operation in the high-voltage filter and reactive power compensation device as in operation capacitors, and marks the capacitor among the in operation capacitors that can provide the largest actual reactive power capacity that is less than the reactive power cut-off requirement as the second preferred capacitor. The controller controls the second preferred capacitor to be disconnected so that reactive power compensation is no longer performed, and obtains the latest reactive power disconnection requirement on the output side after the disconnection is completed. The controller removes the mark of the second preferred capacitor from the capacitor that has already been cut off; The controller determines whether the latest reactive power cut-off demand on the output side after the cut-off is completed is greater than the second preset demand. If so, the controller marks the capacitors currently in operation in the high-voltage filter and reactive power compensation device as in operation capacitors, and marks the capacitor with the largest actual reactive power capacity that can be provided among the in operation capacitors and which is less than the reactive power cut-off requirement as the second preferred capacitor, and then proceeds to the following steps. If not, the controller stops disconnecting the capacitor.

10. A composite high-voltage reactive power compensation system, characterized in that, The composite high-voltage reactive power compensation method as described in any one of claims 1-9 is applied; the system includes a detection module, a calculation module, a controller, and a reactive power compensation device; the detection module and the controller are both communicatively connected to the calculation module; the controller is used to control the start and stop of the reactive power compensation device; the reactive power compensation device includes a thyristor-switched capacitor and a high-voltage filter and reactive power compensation device.

Images