Reactive power compensation control method and system based on photovoltaic reactive power reverse transmission

Abstract

The present application provides a reactive compensation control method and system based on the reverse transmission of photovoltaic reactive power, which includes: measuring the load current forward and reverse controllers to measure the voltage and current phase angles based on the load current forward and reverse, and obtain various related current data in the power supply mode; setting the control strategy of the load current forward and reverse controllers in the power supply mode; based on the load current forward and reverse measurement of the voltage and current phase angles, obtain various related current data in the power generation mode; setting the control strategy of the load current forward and reverse controllers in the power generation mode. The present application provides control strategies under different flow conditions, and realizes the precise control and switching of capacitor compensation under the condition of photovoltaic reactive power reverse transmission, that is, it can realize the inaccurate switching control of the original compensation control strategy, realize more accurate control of reactive power, and improve the bus power factor.

Description

Technical Field

[0001] The present application relates to the technical field of reactive power compensation, and in particular to a reactive power compensation control method and system based on photovoltaic reactive power reverse transmission. Background Art

[0002] With the access of a large number of distributed photovoltaic power sources, the active power and reactive power of some lines are reversed, and the current flow direction has changed. The traditional capacitor control unit controls the switching of capacitors based on the active power and reactive power transmitted to users by the substation bus, without considering the situation that the distribution line transmits reactive power and active power to the bus. It no longer meets the new situation under the existing reactive power flow direction. The reactive power calculation in the system is inaccurate, resulting in the inability to correctly and reasonably switch the capacitor bank. The system power factor is always at a low level, and the large amount of reactive power in the system leads to a large amount of active power loss.

[0003] Based on the above problems, no effective solution has been proposed in the prior art.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present application provides a reactive power compensation control method and system based on photovoltaic reactive power reverse transmission, and the present application mainly includes the following aspects:

[0006] In a first aspect, the present invention provides a reactive power compensation control method based on photovoltaic reactive power reverse transmission, comprising:

[0007] The load current forward and reverse controller is measured to measure the voltage and current phase angle based on the load current forward and reverse directions, and obtain various relevant current data in the power supply mode;

[0008] Setting the control strategy of the load current forward and reverse controller in the power supply mode;

[0009] Based on the forward and reverse measurement of the voltage and current phase angles of the load current, various relevant current data in the power generation mode are obtained;

[0010] Set the control strategy of the load current forward and reverse controller in the power generation mode.

[0011] In one embodiment of the present invention, the load current forward and reverse controller includes an inductive load current forward and reverse controller and a capacitive load current forward and reverse controller.

[0012] In one embodiment of the present invention, the control strategy of the inductive load current forward and reverse controller in the power supply mode specifically includes:

[0013] Setting the power factor threshold of the inductive load current forward and reverse controller in the power supply mode, and comparing the reactive power with the group capacity;

[0014] The investment condition is set as the power factor is lower than the lower limit, and the group capacitor capacity is not higher than the upper limit of the power factor after investment;

[0015] The switching condition is set to the power factor being higher than the upper limit.

[0016] In one embodiment of the present invention, the control strategy of the inductive load current forward and reverse controller in the power supply mode is the same as the control strategy in the power generation mode.

[0017] In one embodiment of the present invention, the control strategy of the capacitive load current forward and reverse controller in the power supply mode specifically includes:

[0018] The capacitor whose reactive power is not negative in the capacitive load current forward and reverse controller in the power supply mode is cut off.

[0019] In one embodiment of the present invention, the control strategy of the capacitive load current forward and reverse controller in the power supply mode is the same as the control strategy in the power generation mode.

[0020] In a second aspect, the embodiment of the present application further provides a reactive power compensation control system based on photovoltaic reactive power reverse transmission, including:

[0021] The power supply mode data measurement module is used to measure the load current forward and reverse controllers to measure the voltage and current phase angles based on the load current forward and reverse directions, and obtain relevant current data in the power supply mode;

[0022] A power supply mode control strategy module, used to set the control strategy of the load current forward and reverse controller in the power supply mode;

[0023] The power generation mode data measurement module is used to measure the voltage and current phase angles based on the forward and reverse directions of the load current to obtain various related current data in the power generation mode;

[0024] The power generation mode control strategy module is used to set the control strategy of the load current forward and reverse controller in the power generation mode.

[0025] In the third aspect, an embodiment of the present application also provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and the machine-readable instructions are executed by the processor when running to perform the steps of the reactive compensation control method based on photovoltaic reactive power reverse transmission as described in any of the above embodiments.

[0026] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the reactive compensation control method based on photovoltaic reactive power reverse transmission as described in any of the above embodiments are executed.

[0027] The above technical solution of the present application has the following advantages compared with the prior art:

[0028] The reactive power compensation control method and system based on the photovoltaic reactive power reverse transmission described in the present application provide control strategies under different flow states, and realize precise control and switching of capacitor compensation under the photovoltaic reactive power reverse transmission. That is, the inaccurate switching control of the original compensation control strategy can be realized, and relatively accurate control of reactive power can be realized, thereby improving the bus power factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0030] Figure 1 A flowchart of a reactive power compensation control method based on photovoltaic reactive power reverse transmission provided by an embodiment of the present application is shown;

[0031] Figure 2 A schematic diagram of the voltage and current phase angle of the inductive load current forward and reverse measurements provided in an embodiment of the present application is shown;

[0032] Figure 3 A schematic diagram of the voltage and current phase angle of the capacitive load current forward and reverse measurements provided in an embodiment of the present application is shown;

[0033] Figure 4 A functional module diagram of a reactive power compensation control system based on photovoltaic reactive power reverse transmission provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0034] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present application, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0035] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0036] In order to enable those skilled in the art to use the contents of this application, the following implementation method is given in combination with the specific application scenario "reactive power compensation based on photovoltaic reactive power reverse transmission". For those skilled in the art, the general principles defined here can be applied to other embodiments and application scenarios without departing from the spirit and scope of this application.

[0037] The following method of the embodiment of the present application can be applied to any scenario that requires reactive power compensation based on photovoltaic reactive power reverse transmission. The embodiment of the present application is not limited to the specific application scenario. Any scheme of reactive power compensation based on photovoltaic reactive power reverse transmission provided by the embodiment of the present application is within the scope of protection of the present application.

[0038] To facilitate the understanding of the present application, the technical solution provided by the present application is described in detail below in conjunction with specific embodiments.

[0039] This application involves a large amount of 0.4 kV photovoltaic grid-connected power generation. A large amount of active power and reactive power cannot be consumed locally, resulting in a large amount of active power and reactive power being sent to the 10kV distribution line through the distribution transformer, and then sent back to the 10 kV bus of the substation. The control strategy of the traditional capacitor control unit no longer meets the new situation under the existing reactive power flow direction, resulting in the inability to correctly and reasonably switch the capacitor bank, providing a power factor that is always at a low level, and a large amount of reactive power in the system The flow leads to a large amount of active power loss.

[0040] Figure 1 The flowchart of a reactive power compensation control method based on photovoltaic reactive power reverse transmission provided by the embodiment of the present application. Figure 1 As shown, including:

[0041] S101: Measure the load current forward and reverse controller to measure the voltage and current phase angle based on the load current forward and reverse directions, and obtain relevant current data in the power supply mode.

[0042] In some possible implementations, the load current forward and reverse controller includes an inductive load current forward and reverse controller and a capacitive load current forward and reverse controller.

[0043] S102: Setting a control strategy of the load current forward and reverse controller in a power supply mode.

[0044] S103: Based on the forward and reverse measurements of the load current, the voltage and current phase angles are measured to obtain relevant current data in the power generation mode.

[0045] S104: Setting a control strategy of the load current forward and reverse controller in a power generation mode.

[0046] In some possible implementations, the control strategy of the inductive load current forward and reverse controller in the power supply mode specifically includes:

[0047] Setting the power factor threshold of the inductive load current forward and reverse controller in the power supply mode, and comparing the reactive power with the group capacity;

[0048] The investment condition is set as the power factor is lower than the lower limit, and the group capacitor capacity is not higher than the upper limit of the power factor after investment;

[0049] The switching condition is set to the power factor being higher than the upper limit.

[0050] In some possible implementations, the control strategy of the inductive load current forward and reverse controller in the power supply mode is the same as the control strategy in the power generation mode.

[0051] In recent years, the number of distributed photovoltaic power sources has continued to increase. During the day when the sun is sufficient, many lines have reverse power transmission. The controller should take into account both calculation and control during photovoltaic power generation.

[0052] For example, the measurement of the forward and reverse controller of the inductive load current is shown in Figure 2 , Figure 2 This is a schematic diagram of the voltage and current phase angle measurement for the inductive load current in the forward and reverse directions. Specifically:

[0053] When the current is forward (power supply mode), the measurement angle θ is the phase angle between the A phase current and the BC phase line voltage, θ = 0 ~ 90; the power factor angle φ is the angle at which the A phase current lags the A phase voltage, φ = 90-θ = 0 ~ 90; the power factor cosφ is positive in this range, and the power factor angle sine value sinφ is positive; active power P = √3U BC I A cosφ is a positive value; reactive power Q = √3U BC I A si nφ is a positive value; capacitors are put into use in this interval, φ decreases, and reactive power decreases.

[0054] Furthermore, the control strategy at this time is to set the upper and lower limits of the power factor and compare the reactive power with the group capacity. The investment condition is that the power factor is lower than the lower limit, and the group capacitor capacity does not exceed the upper limit of the power factor after investment, and both conditions are met at the same time. The cut condition is that the power factor exceeds the upper limit.

[0055] When the current is reversed (generation mode), the measurement angle is the phase angle of the A phase current and the BC phase line voltage = 2π-θ; the power factor angle is the angle of the A phase current lagging the A phase voltage = π-φ; the power factor is negative in this range, and the sine value of the power factor angle is positive; active power P = √3U BC I A cos(π-φ) is a negative value; reactive power Q = √3U BC I A sin(π-φ) is a positive value. When capacitors are put into use in this range, φ is reduced and reactive power decreases.

[0056] Furthermore, the control strategy at this time is the same as that in the power supply mode.

[0057] In some possible implementations, the control strategy of the capacitive load current forward and reverse controller in the power supply mode specifically includes:

[0058] The capacitor whose reactive power is not negative in the capacitive load current forward and reverse controller in the power supply mode is cut off.

[0059] In some possible implementations, the control strategy of the capacitive load current forward and reverse controller in the power supply mode is the same as the control strategy in the power generation mode.

[0060] For example, the measurement of a capacitive load current forward and reverse controller is shown in Figure 3 , Figure 3 This is a schematic diagram of the voltage and current phase angle measurement for the capacitive load current in the forward and reverse directions. Specifically:

[0061] When the current is forward (power supply mode), the measurement angle θ is the phase angle between the A phase current and the BC phase line voltage, θ = 90 ~ 180; the power factor angle φ is the angle at which the A phase current lags the A phase voltage, φ = 90-θ = 0 ~ -90; the power factor cosφ is positive in this range, and the power factor angle sine value sinφ is negative; active power P = √3U BC I A cosφ is a positive value; reactive power Q = √3U BC I A si nφ is a negative value; when capacitors are put into use in this interval, the absolute value of φ increases and the absolute value of reactive power increases.

[0062] Furthermore, the control strategy at this time is to cut off the capacitor according to the reactive power cannot be negative.

[0063] When the current is reversed (generation mode), the measurement angle is the phase angle of the A phase current and the BC phase line voltage = 2π-θ; the power factor angle is the angle of the A phase current lagging the A phase voltage = π+φ; the power factor is negative in this range, and the sine value of the power factor angle is negative; active power P = √3U BC I A cos(π+φ) is a negative value; reactive power Q = √3U BC I A sin(π+φ) is a negative value; capacitors are added in this interval, the absolute value of φ increases, and the absolute value of reactive power increases. At this time, the control strategy is the same as that in the power supply mode, that is, capacitors are cut off.

[0064] Based on the same application concept, the embodiment of the present application also provides a reactive compensation control system based on photovoltaic reactive power reverse transmission, which corresponds to the reactive compensation control method based on photovoltaic reactive power reverse transmission provided in the above embodiment. Since the principle of solving the problem by the system in the embodiment of the present application is similar to the method in the above embodiment of the present application, the implementation of the system can refer to the implementation of the method, and the repeated parts will not be repeated.

[0065] like Figure 4 As shown, Figure 4 A functional module diagram of a reactive power compensation control system based on photovoltaic reactive power reverse transmission provided by this application, the system includes:

[0066] The power supply mode data measurement module 110 is used to measure the load current forward and reverse controllers to measure the voltage and current phase angles based on the load current forward and reverse directions, and obtain relevant current data in the power supply mode;

[0067] A power supply mode control strategy module 120, used to set the control strategy of the load current forward and reverse controller in the power supply mode;

[0068] The power generation mode data measurement module 130 is used to measure the voltage and current phase angle based on the load current in the forward and reverse directions to obtain various related current data in the power generation mode;

[0069] The power generation mode control strategy module 140 is used to set the control strategy of the load current forward and reverse controller in the power generation mode.

[0070] Based on the same application concept, an embodiment of the present invention also provides an electronic device, including: a processor, a memory and a bus, the memory is used to store execution instructions, including internal memory and external memory; the internal memory here is also called internal memory, which is used to temporarily store the operation data in the processor, and the data exchanged with the external memory such as the hard disk, the processor exchanges data with the external memory through the internal memory, when the electronic device is running, the processor and the memory communicate through the bus, so that the processor can execute the steps of the reactive compensation control method based on the photovoltaic reactive power reverse transmission shown in the above method embodiment. The memory stores machine-readable instructions executable by the processor, when the electronic device is running, the processor and the memory communicate through the bus, and the machine-readable instructions are executed by the processor to execute the steps of the reactive compensation control method based on the photovoltaic reactive power reverse transmission as described in any of the above embodiments.

[0071] Based on the same application concept, an embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the reactive compensation control method based on photovoltaic reactive power reverse transmission provided in the above embodiment are executed.

[0072] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0073] The present application is described with reference to flowcharts and / or block diagrams of methods according to embodiments of the present application.

[0074] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A reactive power compensation control method based on photovoltaic reactive power reverse transmission, characterized in that: include: The load current forward and reverse controller is measured to measure the voltage and current phase angle based on the load current forward and reverse directions, and obtain various relevant current data in the power supply mode; Setting the control strategy of the load current forward and reverse controller in the power supply mode; Based on the forward and reverse measurement of the voltage and current phase angles of the load current, various relevant current data in the power generation mode are obtained; Setting the control strategy of the load current forward and reverse controller in the power generation mode; Wherein, the load current forward and reverse controller includes an inductive load current forward and reverse controller and a capacitive load current forward and reverse controller; The control strategy of the inductive load current forward and reverse controller in the power supply mode specifically includes: Setting the power factor threshold of the inductive load current forward and reverse controller in the power supply mode, and comparing the reactive power with the group capacity; The investment condition is set as the power factor is lower than the lower limit, and the group capacitor capacity is not higher than the upper limit of the power factor after investment; The cut-off condition is set to the power factor being higher than the upper limit value; The control strategy of the inductive load current forward and reverse controller in the power supply mode is the same as the control strategy in the power generation mode; The control strategy of the capacitive load current forward and reverse controller in the power supply mode specifically includes: Cutting off the capacitor whose reactive power is not negative in the capacitive load current forward and reverse controller in the power supply mode; The control strategy of the capacitive load current forward and reverse controller in the power supply mode is the same as the control strategy in the power generation mode.

2. A reactive power compensation control system based on photovoltaic reactive power reverse transmission, used to execute the reactive power compensation control method based on photovoltaic reactive power reverse transmission as claimed in claim 1, characterized in that: include: The power supply mode data measurement module is used to measure the load current forward and reverse controllers to measure the voltage and current phase angles based on the load current forward and reverse directions, and obtain relevant current data in the power supply mode; A power supply mode control strategy module, used to set the control strategy of the load current forward and reverse controller in the power supply mode; The power generation mode data measurement module is used to measure the voltage and current phase angles based on the forward and reverse directions of the load current to obtain various related current data in the power generation mode; The power generation mode control strategy module is used to set the control strategy of the load current forward and reverse controller in the power generation mode.

3. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are run by the processor, the steps of the reactive compensation control method based on photovoltaic reactive power reverse transmission as claimed in claim 1 are executed.

4. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the reactive power compensation control method based on photovoltaic reactive power reverse transmission as claimed in claim 1 are executed.

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