Reactive power compensation method and device under photovoltaic access, electronic equipment and storage medium

Abstract

The invention provides a reactive power compensation method and device under photovoltaic access, electronic equipment and a storage medium, and relates to the technical field of new energy power generation. By determining the share of reactive power which can be provided by the SVG and the inverter, coordination control of the SVG and the inverter can be realized, reactive power vacancy of a photovoltaic power generation system can be compensated in time, reactive power can be managed more effectively, voltage fluctuation is avoided, electric energy quality is improved, line loss is reduced, and stability and reliability of a power grid are enhanced at the same time. The coordination control strategy is not only suitable for a large-scale photovoltaic power station, but also suitable for a distributed photovoltaic small power grid and a micro power grid.

Description

Technical Field

[0001] This invention relates to the field of new energy power generation technology, and in particular to a reactive power compensation method, device, electronic equipment and storage medium under photovoltaic grid connection. Background Technology

[0002] With the in-depth development of clean energy technologies, large-scale photovoltaic power generation grids are an important component of clean new energy. At high penetration rates, photovoltaic power output is affected by weather and time, which can lead to fluctuations in grid frequency and voltage.

[0003] Inverters in photovoltaic (PV) power generation systems not only provide active power but also act as virtual synchronous machines or reactive power compensation devices to provide active reactive power support for the system. They provide or absorb reactive power according to grid demand, helping to stabilize voltage and improve the system's power factor. However, existing PV power generation systems rely on static var generators (SVG) to achieve the voltage support requirements at the grid connection point when connected to the grid, without fully utilizing the active reactive power support capability of the inverters in the PV power generation system.

[0004] Therefore, how to tap the reactive power active support capability of the inverter in the photovoltaic power generation system and improve the reactive power coordination and control capability of the photovoltaic power generation system are key issues that urgently need to be addressed. Summary of the Invention

[0005] This invention provides a reactive power compensation method, device, electronic equipment, and storage medium under photovoltaic access, in order to solve the defects existing in related technologies.

[0006] This invention provides a reactive power compensation method under photovoltaic grid connection, comprising: Get the current light intensity; If the light intensity is within a first preset range, obtain the first normalized temperature and first normalized utilization rate of a single inverter in the photovoltaic power generation unit, and the second normalized temperature and second normalized utilization rate of a single static var generator configured for the photovoltaic power generation unit. Based on the light intensity, the first normalized temperature, and the first normalized utilization rate, the first normalized weight of the single inverter is calculated, and based on the second normalized temperature and the second normalized utilization rate, the second normalized weight of the single static var generator is calculated. Based on the reactive power demand of the photovoltaic power generation unit, the first normalization weight, and the second normalization weight, the actual reactive power provided by the single inverter and the actual reactive power provided by the single static var generator are determined.

[0007] According to a reactive power compensation method for photovoltaic (PV) grid connection provided by the present invention, the method comprises determining the actual reactive power provided by a single inverter and the actual reactive power provided by a single static var generator (SVM) based on the reactive power demand of the PV power generation unit, the first normalized weight, and the second normalized weight, and then including: The inductive reactive power provided by the single inverter is determined based on the minimum value between the actual reactive power provided by the single inverter and the maximum reactive power provided by the single inverter. The inductive reactive power provided by the single static var generator is determined based on the minimum value between the actual reactive power provided by the single static var generator and the maximum reactive power provided by the single static var generator.

[0008] According to a reactive power compensation method for photovoltaic (PV) grid connection provided by the present invention, the method comprises determining the actual reactive power provided by a single inverter and the actual reactive power provided by a single static var generator (SVM) based on the reactive power demand of the PV power generation unit, the first normalized weight, and the second normalized weight, and then including: The capacitive reactive power provided by the single inverter is determined based on the minimum value between the actual reactive power provided by the single inverter and the negative value of the maximum reactive power provided by the single inverter. The capacitive reactive power provided by the single static var generator is determined based on the minimum value between the actual reactive power provided by the single static var generator and the negative value of the maximum reactive power provided by the single static var generator.

[0009] According to a reactive power compensation method for photovoltaic access provided by the present invention, the method includes calculating a first normalized weight of a single inverter based on the irradiance, the first normalized temperature, and the first normalized utilization rate, and calculating a second normalized weight of a single static var generator based on the second normalized temperature and the second normalized utilization rate, comprising: The first initial weight of the single inverter is calculated based on the product of the light intensity, the first normalized temperature and the first normalized utilization rate, and the second initial weight of the single static var generator is calculated based on the product of the second normalized temperature and the second normalized utilization rate. The normalization factor is determined based on the sum of the first initial weight of each inverter in the photovoltaic power generation unit and the second initial weight of each static var generator configured for the photovoltaic power generation unit. The first normalized weight is calculated based on the proportion of the first initial weight in the normalization factor, and the second normalized weight is calculated based on the proportion of the second initial weight in the normalization factor.

[0010] According to the reactive power compensation method under photovoltaic access provided by the present invention, after obtaining the current irradiance, the method further includes: If the light intensity is within the second preset range, the actual reactive power provided by the single inverter is adjusted first. When the actual reactive power output by the photovoltaic power generation unit reaches saturation, each static var generator configured for the photovoltaic power generation unit is activated to compensate for the reactive power deficit. Wherein, the upper limit of the second preset range is less than the lower limit of the first preset range.

[0011] According to a reactive power compensation method for photovoltaic (PV) grid connection provided by the present invention, the method of preferentially adjusting the actual reactive power provided by the individual inverter, and when the actual reactive power output by the PV power generation unit reaches saturation, activating each static var generator configured for the PV power generation unit to perform reactive power deficit compensation, includes: If the ratio of the required reactive power to the number of inverters in the photovoltaic power generation unit is within the range of the maximum reactive power provided by a single inverter, then the actual reactive power provided by the single inverter is determined to be the minimum value between the ratio and the maximum reactive power provided by the single inverter, and the actual reactive power provided by the single static var generator is determined to be 0; if the ratio is greater than the maximum reactive power provided by the single inverter, then the actual reactive power provided by the single inverter is determined to be the maximum reactive power provided by the single inverter, and the difference between the required reactive power and the maximum reactive power multiple of the number of inverters is determined, and the minimum value between the difference and the maximum reactive power of the single static var generator is taken as the actual reactive power provided by the single static var generator. If the ratio is less than the negative value of the maximum reactive power provided by the single inverter, then the actual reactive power provided by the single inverter is determined to be the negative value of the maximum reactive power provided by the single inverter, and the sum of the required reactive power and the maximum reactive power that is a multiple of the inverter is determined. The minimum value between the sum and the negative value of the maximum reactive power of the single static var generator is taken as the actual reactive power provided by the single static var generator.

[0012] According to the present invention, a reactive power compensation method under photovoltaic grid connection is provided, the method further includes: If the photovoltaic power generation unit malfunctions, both the single inverter and the single static var generator will be controlled to operate in maximum reactive power output mode.

[0013] The present invention also provides a reactive power compensation device under photovoltaic grid connection, comprising: The first acquisition module is used to acquire the light intensity at the current moment; The second acquisition module is used to acquire, if the light intensity is within a first preset range, the first normalized temperature and the first normalized utilization rate of a single inverter in the photovoltaic power generation unit, and the second normalized temperature and the second normalized utilization rate of a single static var generator configured for the photovoltaic power generation unit. The weight calculation module is used to calculate the first normalized weight of the single inverter based on the light intensity, the first normalized temperature and the first normalized utilization rate, and to calculate the second normalized weight of the single static var generator based on the second normalized temperature and the second normalized utilization rate. The power compensation module is used to determine the actual reactive power provided by the single inverter and the actual reactive power provided by the single static var generator based on the reactive power demand of the photovoltaic power generation unit, the first normalization weight, and the second normalization weight.

[0014] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the reactive power compensation method under photovoltaic access as described above.

[0015] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the reactive power compensation method under photovoltaic access as described above.

[0016] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the reactive power compensation method under photovoltaic access as described above.

[0017] The present invention provides a method, apparatus, electronic device, and storage medium for reactive power compensation under photovoltaic (PV) grid integration. This method, under conditions where sunlight intensity is within a first preset range, determines the share of reactive power each individual inverter and static var generator (SVG) can provide by combining their individual parameters. This enables coordinated control of the SVG and inverter, timely compensation for reactive power deficits in the PV power generation system, more effective reactive power management, prevention of voltage fluctuations, improved power quality, reduced line losses, and enhanced grid stability and reliability. This coordinated control strategy is applicable not only to large-scale PV power plants but also to small grids and microgrids that include distributed PV systems. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating the reactive power compensation method under photovoltaic grid connection provided by the present invention.

[0020] Figure 2 This is the collaborative control diagram of the regional power grid inverter and SVG provided by the present invention.

[0021] Figure 3 This is a schematic diagram of the reactive power compensation device under photovoltaic access provided by the present invention.

[0022] Figure 4 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] Figure 1 This is a flowchart illustrating a reactive power compensation method under photovoltaic grid connection provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the method includes: S1, obtain the light intensity at the current moment; S2, if the light intensity is within a first preset range, obtain the first normalized temperature and first normalized utilization rate of a single inverter in the photovoltaic power generation unit, and the second normalized temperature and second normalized utilization rate of a single static var generator configured for the photovoltaic power generation unit. S3, based on the light intensity, the first normalized temperature and the first normalized utilization rate, calculate the first normalized weight of the single inverter, and based on the second normalized temperature and the second normalized utilization rate, calculate the second normalized weight of the single static var generator. S4. Based on the reactive power demand of the photovoltaic power generation unit, the first normalization weight, and the second normalization weight, determine the actual reactive power provided by the single inverter and the actual reactive power provided by the single static var generator.

[0025] Specifically, the reactive power compensation method under photovoltaic access provided in this embodiment of the invention is executed by a reactive power compensation device under photovoltaic access. This device can be configured in a computer, which can be a local computer or a cloud computer. The local computer can be a computer, tablet, etc., and no specific limitation is made here.

[0026] A photovoltaic (PV) power generation system may include multiple PV power generation units; for example, a PV power generation system may include M PV power generation units. Each PV power generation unit may include N PV modules and an inverter connected to each PV module.

[0027] In a photovoltaic power generation system, each photovoltaic power generation unit can be provided with K SVGs. Here, M, N, and K are all integers greater than or equal to 1.

[0028] The active power output of the N inverters in each photovoltaic power generation unit of the photovoltaic power generation system is P. pv11 P pv12 ... P pvmn ... P pvMN P pvmn Let P be the active power output of the nth inverter in the mth photovoltaic power generation unit; the active power output of each inverter is P. pv11 P pv12 ... P pvmn ... P pvMN The maximum reactive power output at that time is Q pv11,max Q pv12,max Q pvmn,max Q pvMN,max Q pvmn,max Q represents the maximum reactive power output of the nth inverter in the mth photovoltaic power generation unit; the actual reactive power output of each inverter is Q. pv11,t Q pv12,t Q pvmn,t Q pvMN,t Q pvmn,t Q is the actual reactive power output of the nth inverter in the mth photovoltaic power generation unit; Q is the maximum reactive power output of the kth SVG. SVGk,max The actual reactive power output of the k-th SVG is Q. SVGk,t The reactive power required for each photovoltaic power generation unit is Q. sys The combined maximum reactive power output of all inverters and SVGs is Q. total,t .

[0029] like Figure 2As shown, N inverters and one SVG work together to provide the required reactive power for the photovoltaic power generation unit. The N inverters are connected to a first transformer T1 via impedance Z1, and the first transformer T1 is connected to the grid connection point. The other side of the grid connection point is connected to a second transformer T2 via a second impedance Z2, and the second transformer T2 is used to connect to the grid's output power supply S. Here, the actual voltage U at the grid connection point... pcc Expected voltage U ref The maximum voltage at the grid connection point is U. pcc,max The minimum voltage is U pcc,min .

[0030] First, step S1 is executed to obtain the current light intensity. Then, it can be determined whether the light intensity value is within a first preset range. This first preset range can be a range where the light intensity is greater than or equal to a preset threshold. This preset threshold can be set as needed and is not specifically limited here. It can be understood that this first preset range can be the normal light intensity range under sunlight.

[0031] Then, step S2 is executed. If the current light intensity is within the first preset range, it indicates that the sunshine is normal, that is, it is daytime or the light conditions are sufficient. At this time, the first normalized temperature and the first normalized utilization rate of a single inverter in the photovoltaic power generation unit, as well as the second normalized temperature and the second normalized utilization rate of a single SVG configured for the photovoltaic power generation unit, can be obtained.

[0032] The first normalized temperature of a single inverter can be expressed as t pv The first normalized utilization rate can be expressed as φ pv The second normalized temperature of a single SVG configured for a photovoltaic power generation unit can be expressed as t SVG The second normalized utilization rate can be expressed as φ SVG If the light intensity is represented by l, then: 0 ≤ l ≤ 1, 0 ≤ t pv ≤1, 0≤φ pv ≤1; 0≤t SVG ≤1, 0≤φ SVG ≤1.

[0033] Then proceed to step S3, the first normalized temperature t pv First normalized utilization rate φ pv And the light intensity l is the first normalized weight ω′ of a single inverter. pv The key influencing factors, therefore, are light intensity l and the first normalized temperature t. pv and the first normalized utilization rate φ pv Calculate the first normalized weight ω′ of a single inverter. pv .

[0034] Second normalization temperature t SVG And the second normalized utilization rate φ SVG The second normalized weights ω′ of each individual static var generator are all second normalized weights. SVG The key influencing factors can be determined based on the second normalized temperature t. SVG And the second normalized utilization rate φ SVG Calculate the second normalized weight ω′ of a single static var generator. SVG .

[0035] Finally, step S4 is executed to adjust the first normalized weight ω′ of a single inverter. pv And the second normalized utilization rate ω′ of a single static var generator SVG The reactive power contribution ratios of a single inverter and a single static var generator are respectively used to calculate the required reactive power Q of the photovoltaic power generation unit. sys The first normalized weight ω′ of a single inverter pv and the second normalized weight ω′ of a single static var generator SVG This involves determining the first actual reactive power provided by a single inverter and the second actual reactive power provided by a single static var generator. Here, the first normalized weight ω′ of the single inverter can be used... pv With demand reactive power Q sys The product of these factors represents the actual reactive power provided by a single inverter, and the second normalized weight ω′ of the single static var generator is used to represent this. SVG With demand reactive power Q sys The product of these two values ​​represents the actual reactive power of a single static var generator (SVR). Taking the example of a single inverter being the nth inverter in the mth photovoltaic power generation unit and a single SVR being the kth SVR, we have:

[0036] The reactive power compensation method under photovoltaic access provided in this embodiment of the invention first obtains the current irradiance; then, if the irradiance is within a first preset range, it obtains the first normalized temperature and first normalized utilization rate of a single inverter in the photovoltaic power generation unit, and the second normalized temperature and second normalized utilization rate of a single static var generator configured for the photovoltaic power generation unit; subsequently, based on the irradiance, the first normalized temperature, and the first normalized utilization rate, it calculates the first normalized weight of a single inverter, and based on the second normalized temperature and the second normalized utilization rate, it calculates the second normalized weight of a single static var generator; finally, based on the required reactive power of the photovoltaic power generation unit, the first normalized weight, and the second normalized weight, it determines the actual reactive power provided by a single inverter and the actual reactive power provided by a single static var generator. This method, under conditions where sunlight intensity is within a first preset range, combines the individual parameters of a single inverter and a single static var generator (SVG) to determine the share of reactive power each can provide. This enables coordinated control of the SVG and inverter, timely compensation for reactive power deficits in the photovoltaic power generation system, more effective reactive power management, prevention of voltage fluctuations, improved power quality, reduced line losses, and enhanced grid stability and reliability. This coordinated control strategy is applicable not only to large-scale photovoltaic power plants but also to small grids and microgrids that include distributed photovoltaic systems.

[0037] Based on the above embodiments, the step of determining the actual reactive power provided by the individual inverter and the actual reactive power provided by the individual static var generator based on the required reactive power of the photovoltaic power generation unit, the first normalized weight, and the second normalized weight, then includes: The inductive reactive power provided by the single inverter is determined based on the minimum value between the actual reactive power provided by the single inverter and the maximum reactive power provided by the single inverter. The inductive reactive power provided by the single static var generator is determined based on the minimum value between the actual reactive power provided by the single static var generator and the maximum reactive power provided by the single static var generator.

[0038] Specifically, the reactive power provided by the inverter and SVG respectively does not exceed their respective maximum output reactive power, that is: Among them, Q′ pvmn，t Q′ is the inductive reactive power provided by the nth inverter in the mth photovoltaic power generation unit. SVGk，t The inductive reactive power provided to the k-th static var generator.

[0039] Based on the above embodiments, the step of determining the actual reactive power provided by the individual inverter and the actual reactive power provided by the individual static var generator based on the required reactive power of the photovoltaic power generation unit, the first normalized weight, and the second normalized weight, then includes: The capacitive reactive power provided by the single inverter is determined based on the minimum value between the actual reactive power provided by the single inverter and the negative value of the maximum reactive power provided by the single inverter. The capacitive reactive power provided by the single static var generator is determined based on the minimum value between the actual reactive power provided by the single static var generator and the negative value of the maximum reactive power provided by the single static var generator.

[0040] Specifically, the reactive power provided by the inverter and SVG respectively does not exceed the negative value of their respective maximum output reactive power, that is: Among them, Q″ pvmn，t Q″ is the capacitive reactive power provided by the nth inverter in the mth photovoltaic power generation unit. SVGk，t The capacitive reactive power provided to the k-th static var generator.

[0041] Based on the above embodiments, the step of calculating the first normalized weight of the individual inverter based on the light intensity, the first normalized temperature, and the first normalized utilization rate, and calculating the second normalized weight of the individual static var generator based on the second normalized temperature and the second normalized utilization rate, includes: The first initial weight of the single inverter is calculated based on the product of the light intensity, the first normalized temperature and the first normalized utilization rate, and the second initial weight of the single static var generator is calculated based on the product of the second normalized temperature and the second normalized utilization rate. The normalization factor is determined based on the sum of the first initial weight of each inverter in the photovoltaic power generation unit and the second initial weight of each static var generator configured for the photovoltaic power generation unit. The first normalized weight is calculated based on the proportion of the first initial weight in the normalization factor, and the second normalized weight is calculated based on the proportion of the second initial weight in the normalization factor.

[0042] Specifically, when calculating the first normalized weight of a single inverter and the second normalized weight of a single static var generator, the first normalized temperature t can be used as a reference. pv First normalized utilization rate φ pvThe product of the light intensity l and the initial weight ω of a single inverter is calculated. pv , has ω pv =l·t pv ·φ pv , 0≤ω pv ≤1.

[0043] According to the second normalization temperature t SVG With the second normalized utilization rate φ SVG The product of these factors is used to calculate the second initial weight ω of a single static var generator. SVG , has: ω SVG =t SVG ·φ SVG , 0≤ω SVG ≤1.

[0044] Subsequently, the normalization factor can be determined by summing the first initial weights of each inverter in the photovoltaic power generation unit and the second initial weights of each static var generator configured for the photovoltaic power generation unit.

[0045] Finally, the proportion of the first initial weight in the normalization factor, that is, the ratio of the first initial weight to the normalization factor, is taken as the first normalized weight ω′. pv The proportion of the second initial weight in the normalization factor, i.e., the ratio of the second initial weight to the normalization factor, is taken as the second normalized weight ω′. SVG .

[0046] If each photovoltaic power generation unit has N inverters with the same capacity and only one SVG is configured, then the normalization factor can be expressed as: C = N·ω pv +ω SVG The first normalized weight can be expressed as ω' pv =ω pv / C, the second normalized weight can be expressed as ω' SVG =ω SVG / C.

[0047] Based on the above embodiments, the step of obtaining the light intensity at the current moment further includes: If the light intensity is within the second preset range, the actual reactive power provided by the single inverter is adjusted first. When the actual reactive power output by the photovoltaic power generation unit reaches saturation, each static var generator configured for the photovoltaic power generation unit is activated to compensate for the reactive power deficit. Wherein, the upper limit of the second preset range is less than the lower limit of the first preset range.

[0048] Specifically, after executing step S1, if the current light intensity is within the second preset range, and the upper limit of the second preset range is less than the lower limit of the first preset range, it indicates that it is nighttime or the light conditions are insufficient. At this time, the active power output of each inverter is 0, the inverter is disconnected from the photovoltaic module, and the inverter switches to "SVG working mode", that is, it only provides reactive power.

[0049] At this point, the actual reactive power provided by a single inverter can be adjusted first. When the actual reactive power output by the photovoltaic power generation unit reaches saturation, the static var generators configured for the photovoltaic power generation unit are activated to compensate for the reactive power deficit.

[0050] If the ratio of the required reactive power to the number of inverters in the photovoltaic power generation unit is within the range of the maximum reactive power provided by a single inverter, then the actual reactive power provided by a single inverter is determined to be the minimum of the ratio and the maximum reactive power provided by a single inverter, and the actual reactive power provided by a single static var generator is determined to be 0. That is: Among them, [-Q pvmn，max Q pvmn，max [This refers to the range of maximum reactive power provided by the nth inverter in the mth photovoltaic power generation unit.] It is the ratio of the required reactive power to the number of inverters in the photovoltaic power generation unit.

[0051] If the ratio of the required reactive power to the number of inverters in the photovoltaic power generation unit is greater than the maximum reactive power provided by a single inverter, then the actual reactive power provided by a single inverter is determined to be the maximum reactive power provided by that single inverter. Furthermore, the difference between the required reactive power and the maximum reactive power multiple of the number of inverters is determined, and the minimum of this difference and the maximum reactive power of a single static var generator (SVM) is taken as the actual reactive power provided by that single SVM. That is: Among them, Q sys -NQ pvmn，max It is the difference between the required reactive power and the maximum reactive power multiple of the inverter.

[0052] If the ratio of the required reactive power to the number of inverters in the photovoltaic power generation unit is less than the negative value of the maximum reactive power provided by a single inverter, then the actual reactive power provided by a single inverter is determined to be the negative value of the maximum reactive power provided by a single inverter. Furthermore, the sum of the required reactive power and the maximum reactive power multiple of the number of inverters is determined, and the minimum of this sum and the negative value of the maximum reactive power of a single static var generator (SVM) is taken as the actual reactive power provided by a single SVM. That is: Among them, Q sys +NQ pvmn，max It is the sum of the required reactive power and the maximum reactive power multiple of the number of inverters.

[0053] Meanwhile, the actual voltage U at the grid connection point pcc U also needs to be satisfied pcc，min ≤U pcc ≤U pcc，max .

[0054] Based on the above embodiments, the method further includes: If the photovoltaic power generation unit malfunctions, both the single inverter and the single static var generator will be controlled to operate in maximum reactive power output mode.

[0055] Specifically, the method also includes the ability to control both a single inverter and a single static var generator to operate in maximum reactive power output mode in the event of a failure in the photovoltaic power generation unit.

[0056] That is:

[0057] In summary, the reactive power compensation method under photovoltaic access provided in this embodiment of the invention can effectively compensate for the reactive power deficit of the system in a timely manner when the monitored quantities such as voltage deviation, power factor, and current phase angle of the photovoltaic power generation system deviate from the target set values ​​under different scenarios such as normal sunshine, insufficient sunshine at night / under insufficient sunshine conditions, and failure of photovoltaic power generation units. This is achieved by coordinating and optimizing the actual reactive power output of the inverter in the photovoltaic power generation unit and the SVG in the photovoltaic power generation system. As a result, the system voltage fluctuation is reduced, line loss is reduced, and the system power quality is improved.

[0058] like Figure 3 As shown, based on the above embodiments, this embodiment of the invention provides a reactive power compensation device under photovoltaic access, comprising: The first acquisition module 31 is used to acquire the light intensity at the current moment; The second acquisition module 32 is used to acquire, if the light intensity is within a first preset range, the first normalized temperature and the first normalized utilization rate of a single inverter in the photovoltaic power generation unit, and the second normalized temperature and the second normalized utilization rate of a single static var generator configured for the photovoltaic power generation unit. The weight calculation module 33 is used to calculate the first normalized weight of the single inverter based on the light intensity, the first normalized temperature and the first normalized utilization rate, and to calculate the second normalized weight of the single static var generator based on the second normalized temperature and the second normalized utilization rate. The power compensation module 34 is used to determine the actual reactive power provided by the single inverter and the actual reactive power provided by the single static var generator based on the reactive power demand of the photovoltaic power generation unit, the first normalization weight, and the second normalization weight.

[0059] Based on the above embodiments, the reactive power compensation device for photovoltaic access provided in this embodiment of the invention, wherein the power compensation module is further used for: The inductive reactive power provided by the single inverter is determined based on the minimum value between the actual reactive power provided by the single inverter and the maximum reactive power provided by the single inverter. The inductive reactive power provided by the single static var generator is determined based on the minimum value between the actual reactive power provided by the single static var generator and the maximum reactive power provided by the single static var generator.

[0060] Based on the above embodiments, the reactive power compensation device for photovoltaic access provided in this embodiment of the invention, wherein the power compensation module is further used for: The capacitive reactive power provided by the single inverter is determined based on the minimum value between the actual reactive power provided by the single inverter and the negative value of the maximum reactive power provided by the single inverter. The capacitive reactive power provided by the single static var generator is determined based on the minimum value between the actual reactive power provided by the single static var generator and the negative value of the maximum reactive power provided by the single static var generator.

[0061] Based on the above embodiments, the reactive power compensation device under photovoltaic access provided in this embodiment of the invention, wherein the weight calculation module is specifically used for: The first initial weight of the single inverter is calculated based on the product of the light intensity, the first normalized temperature and the first normalized utilization rate, and the second initial weight of the single static var generator is calculated based on the product of the second normalized temperature and the second normalized utilization rate. The normalization factor is determined based on the sum of the first initial weight of each inverter in the photovoltaic power generation unit and the second initial weight of each static var generator configured for the photovoltaic power generation unit. The first normalized weight is calculated based on the proportion of the first initial weight in the normalization factor, and the second normalized weight is calculated based on the proportion of the second initial weight in the normalization factor.

[0062] Based on the above embodiments, the reactive power compensation device for photovoltaic access provided in this embodiment of the invention, wherein the power compensation module is further used for: If the light intensity is within the second preset range, the actual reactive power provided by the single inverter is adjusted first. When the actual reactive power output by the photovoltaic power generation unit reaches saturation, each static var generator configured for the photovoltaic power generation unit is activated to compensate for the reactive power deficit. Wherein, the upper limit of the second preset range is less than the lower limit of the first preset range.

[0063] Based on the above embodiments, the reactive power compensation device for photovoltaic access provided in this embodiment of the invention, wherein the power compensation module is further specifically used for: If the ratio of the required reactive power to the number of inverters in the photovoltaic power generation unit is within the range of the maximum reactive power provided by a single inverter, then the actual reactive power provided by the single inverter is determined to be the minimum value between the ratio and the maximum reactive power provided by the single inverter, and the actual reactive power provided by the single static var generator is determined to be 0; if the ratio is greater than the maximum reactive power provided by the single inverter, then the actual reactive power provided by the single inverter is determined to be the maximum reactive power provided by the single inverter, and the difference between the required reactive power and the maximum reactive power multiple of the number of inverters is determined, and the minimum value between the difference and the maximum reactive power of the single static var generator is taken as the actual reactive power provided by the single static var generator. If the ratio is less than the negative value of the maximum reactive power provided by the single inverter, then the actual reactive power provided by the single inverter is determined to be the negative value of the maximum reactive power provided by the single inverter, and the sum of the required reactive power and the maximum reactive power that is a multiple of the inverter is determined. The minimum value between the sum and the negative value of the maximum reactive power of the single static var generator is taken as the actual reactive power provided by the single static var generator.

[0064] Based on the above embodiments, the reactive power compensation device for photovoltaic access provided in this embodiment of the invention, wherein the power compensation module is further specifically used for: If the photovoltaic power generation unit malfunctions, both the single inverter and the single static var generator will be controlled to operate in maximum reactive power output mode.

[0065] Specifically, the functions of each module in the photovoltaic-connected reactive power compensation device provided in this embodiment of the invention correspond one-to-one with the operation flow of each step in the above-mentioned method-like embodiments, and the achieved effects are also the same. For details, please refer to the above embodiments, and this will not be repeated in this embodiment of the invention.

[0066] Figure 4 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 4As shown, the electronic device may include a processor 410, a communication interface 420, a memory 430, and a communication bus 440. The processor 410, communication interface 420, and memory 430 communicate with each other via the communication bus 440. The processor 410 can call logical instructions stored in the memory 430 to execute the reactive power compensation method under photovoltaic access provided in the above embodiments.

[0067] Furthermore, the logical instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to related technologies, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0068] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the reactive power compensation method under photovoltaic access provided in the above embodiments.

[0069] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the reactive power compensation method under photovoltaic access provided in the above embodiments.

[0070] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0071] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of software products. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reactive power compensation method under photovoltaic grid connection, characterized in that, include: Get the current light intensity; If the light intensity is within a first preset range, obtain the first normalized temperature and first normalized utilization rate of a single inverter in the photovoltaic power generation unit, and the second normalized temperature and second normalized utilization rate of a single static var generator configured for the photovoltaic power generation unit. Based on the light intensity, the first normalized temperature, and the first normalized utilization rate, the first normalized weight of the single inverter is calculated, and based on the second normalized temperature and the second normalized utilization rate, the second normalized weight of the single static var generator is calculated. Based on the reactive power demand of the photovoltaic power generation unit, the first normalization weight, and the second normalization weight, the actual reactive power provided by the single inverter and the actual reactive power provided by the single static var generator are determined.

2. The reactive power compensation method under photovoltaic grid connection according to claim 1, characterized in that, The process of determining the actual reactive power provided by the single inverter and the actual reactive power provided by the single static var generator based on the required reactive power of the photovoltaic power generation unit, the first normalization weight, and the second normalization weight, then includes: determining the inductive reactive power provided by the single inverter based on the minimum value between the actual reactive power provided by the single inverter and the maximum reactive power provided by the single inverter. The inductive reactive power provided by the single static var generator is determined based on the minimum value between the actual reactive power provided by the single static var generator and the maximum reactive power provided by the single static var generator.

3. The reactive power compensation method under photovoltaic grid connection according to claim 1, characterized in that, The process of determining the actual reactive power provided by the single inverter and the actual reactive power provided by the single static var generator based on the required reactive power of the photovoltaic power generation unit, the first normalization weight, and the second normalization weight, then includes: determining the capacitive reactive power provided by the single inverter based on the minimum value between the actual reactive power provided by the single inverter and the negative value of the maximum reactive power provided by the single inverter. The capacitive reactive power provided by the single static var generator is determined based on the minimum value between the actual reactive power provided by the single static var generator and the negative value of the maximum reactive power provided by the single static var generator.

4. The reactive power compensation method under photovoltaic grid connection according to claim 1, characterized in that, The calculation of the first normalized weight of the individual inverter based on the light intensity, the first normalized temperature, and the first normalized utilization rate, and the calculation of the second normalized weight of the individual static var generator based on the second normalized temperature and the second normalized utilization rate, includes: The first initial weight of the single inverter is calculated based on the product of the light intensity, the first normalized temperature and the first normalized utilization rate, and the second initial weight of the single static var generator is calculated based on the product of the second normalized temperature and the second normalized utilization rate. The normalization factor is determined based on the sum of the first initial weight of each inverter in the photovoltaic power generation unit and the second initial weight of each static var generator configured for the photovoltaic power generation unit. The first normalized weight is calculated based on the proportion of the first initial weight in the normalization factor, and the second normalized weight is calculated based on the proportion of the second initial weight in the normalization factor.

5. The reactive power compensation method under photovoltaic grid connection according to any one of claims 1-4, characterized in that, The process of obtaining the current light intensity also includes: If the light intensity is within the second preset range, the actual reactive power provided by the single inverter is adjusted first. When the actual reactive power output by the photovoltaic power generation unit reaches saturation, each static var generator configured for the photovoltaic power generation unit is activated to compensate for the reactive power deficit. Wherein, the upper limit of the second preset range is less than the lower limit of the first preset range.

6. The reactive power compensation method under photovoltaic grid connection according to claim 5, characterized in that, The process of prioritizing the adjustment of the actual reactive power provided by the individual inverter, and then, when the actual reactive power output by the photovoltaic power generation units reaches saturation, activating each static var generator configured for the photovoltaic power generation units to compensate for reactive power deficit, includes: If the ratio of the required reactive power to the number of inverters in the photovoltaic power generation unit is within the range of the maximum reactive power provided by a single inverter, then the actual reactive power provided by the single inverter is determined to be the minimum value between the ratio and the maximum reactive power provided by the single inverter, and the actual reactive power provided by the single static var generator is determined to be 0; if the ratio is greater than the maximum reactive power provided by the single inverter, then the actual reactive power provided by the single inverter is determined to be the maximum reactive power provided by the single inverter, and the difference between the required reactive power and the maximum reactive power multiple of the number of inverters is determined, and the minimum value between the difference and the maximum reactive power of the single static var generator is taken as the actual reactive power provided by the single static var generator. If the ratio is less than the negative value of the maximum reactive power provided by the single inverter, then the actual reactive power provided by the single inverter is determined to be the negative value of the maximum reactive power provided by the single inverter, and the sum of the required reactive power and the maximum reactive power that is a multiple of the inverter is determined. The minimum value between the sum and the negative value of the maximum reactive power of the single static var generator is taken as the actual reactive power provided by the single static var generator.

7. The reactive power compensation method under photovoltaic grid connection according to any one of claims 1-4, characterized in that, The method further includes: If the photovoltaic power generation unit malfunctions, both the single inverter and the single static var generator will be controlled to operate in maximum reactive power output mode.

8. A reactive power compensation device under photovoltaic grid connection, characterized in that, include: The first acquisition module is used to acquire the light intensity at the current moment; The second acquisition module is used to acquire, if the light intensity is within a first preset range, the first normalized temperature and the first normalized utilization rate of a single inverter in the photovoltaic power generation unit, and the second normalized temperature and the second normalized utilization rate of a single static var generator configured for the photovoltaic power generation unit. The weight calculation module is used to calculate the first normalized weight of the single inverter based on the light intensity, the first normalized temperature and the first normalized utilization rate, and to calculate the second normalized weight of the single static var generator based on the second normalized temperature and the second normalized utilization rate. The power compensation module is used to determine the actual reactive power provided by the single inverter and the actual reactive power provided by the single static var generator based on the reactive power demand of the photovoltaic power generation unit, the first normalization weight, and the second normalization weight.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the reactive power compensation method under photovoltaic access as described in any one of claims 1-7.

10. A non-transitory 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 reactive power compensation method under photovoltaic access as described in any one of claims 1-7.

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