Charging station-photovoltaic-based voltage control method, device and computer equipment

Abstract

This application provides a voltage control method, device, and computer equipment based on a charging station-photovoltaic system. The method includes: determining the target node by real-time monitoring to identify any nodes in the system experiencing low voltage exceedances; then, progressively attempting to compensate for the voltage gap based on the reactive and active power of the photovoltaic system. If photovoltaic regulation still cannot completely resolve the fault, further attempts are made to disconnect the charging station load to continue improving the voltage. This method fully utilizes the flexibility and power supply characteristics of charging piles, and coordinates with photovoltaic active and reactive power control for synergistic regulation. Based on the target node, it improves the overall node voltage of the 10kV distribution network to alleviate low voltage problems. Furthermore, this strategy does not involve optimization solutions or model calculations, resulting in less computational pressure on the hardware and software and significantly improving regulation efficiency.

Description

Technical Field

[0001] This application relates to the field of power system technology, and in particular to a voltage control method, apparatus, computer equipment, and storage medium based on a charging station-photovoltaic system. Background Technology

[0002] With the continuous advancement of new power system construction, higher requirements have been placed on the power supply reliability and voltage quality of traditional distribution networks. Currently, in the daily operation of 10kV medium-voltage distribution networks, the grid connection of large-scale distributed power sources and various new types of electrical loads has had a significant impact on the distribution network. Distributed power source grid connection may lead to the risk of localized overvoltage, while the large-scale connection of new electrical loads to the end of lines may also lead to the risk of low voltage at the end of the lines. Therefore, finding suitable and feasible voltage regulation methods for distribution networks is of significant necessity to address these voltage issues. Traditional regulation methods suffer from poor regulation effects or low computational efficiency. Summary of the Invention

[0003] The purpose of this application is to at least solve one of the aforementioned technical defects, particularly the problems of poor voltage regulation or low computational efficiency in the prior art.

[0004] In a first aspect, this application provides a voltage control method based on a charging station-photovoltaic system, comprising:

[0005] Determine whether each node has a low voltage over-limit fault. If so, identify the node that triggered the low voltage over-limit fault as the target node and determine the low voltage deviation gap of the target node.

[0006] The reactive power demand is obtained based on the low voltage deviation gap;

[0007] If the reactive power demand is less than or equal to the current maximum reactive power supply of the photovoltaic modules in the power system, then the photovoltaic modules are controlled to increase their reactive power output based on the reactive power demand; otherwise, the active power demand is obtained based on the low voltage deviation gap and the current reactive power output of the photovoltaic modules.

[0008] If the active power demand is less than or equal to the current maximum active power supply of the photovoltaic modules in the power system, then the reactive power output and active power output of the photovoltaic modules are increased according to the maximum reactive power supply and active power demand, respectively; otherwise, the charging load shedding demand is obtained according to the low voltage deviation gap, the current reactive power output and the current active power output of the photovoltaic modules.

[0009] If the demand for charging load shedding is less than or equal to the current load of the charging station in the power system, then the reactive power and active power output of the photovoltaic modules are increased according to the maximum reactive power supply and the maximum active power supply, respectively, and the load of the charging station is shedding according to the demand for charging load shedding; otherwise, the reactive power and active power output of the photovoltaic modules are increased according to the maximum reactive power supply and the maximum active power supply, respectively, and all loads of the charging station are shedding.

[0010] In one embodiment, the voltage control method based on the charging station-photovoltaic system further includes, before determining whether a low-voltage over-limit fault has occurred at each node:

[0011] Acquire the active power offset, reactive power offset, and voltage offset of each node in the power system in each acquisition interval of the previous preset cycle;

[0012] Based on the active power offset and voltage offset, the active power-voltage sensitivity factor is obtained, and based on the reactive power offset and voltage offset, the reactive power-voltage sensitivity factor is obtained. The active power-voltage sensitivity factor is used to determine the active power demand and the charging load shedding demand, while the reactive power-voltage sensitivity factor is used to determine the reactive power demand, active power demand, and the charging load shedding demand.

[0013] In one embodiment, an active-voltage sensitivity factor is obtained based on each active power offset and voltage offset, including:

[0014] Substituting the active power offset and voltage offset into the first expression, we obtain the active power-voltage sensitivity factor; where the first expression is:

[0015]

[0016] Where, δ P-U The active power-voltage sensitivity factor is denoted by n, where n is the total number of nodes, T is the total number of times active power offset, reactive power offset, and voltage offset are collected, and ΔU is the voltage-voltage sensitivity factor. i,t Let ΔP be the voltage offset of the i-th node between acquisition time t and acquisition time t-1. i,t This represents the active power offset of the i-th node between acquisition time t and acquisition time t-1.

[0017] In one embodiment, a reactive power-voltage sensitivity factor is obtained based on each reactive power offset and voltage offset, including:

[0018] Substituting the reactive power offset and voltage offset into the second expression, we obtain the reactive power-voltage sensitivity factor; where the second expression is:

[0019]

[0020] Where, δ Q-UHere, ΔU is the reactive power-voltage sensitivity factor, n is the total number of nodes, T is the total number of times when active power offset, reactive power offset, and voltage offset are collected, and ΔU is the reactive power-voltage sensitivity factor. i,t Let ΔQ be the voltage offset of the i-th node between acquisition time t and acquisition time t-1. i,t This represents the reactive power offset of the i-th node between acquisition time t and acquisition time t-1.

[0021] In one embodiment, the reactive power demand is obtained based on the low voltage deviation gap, including:

[0022] Substituting the low voltage deviation gap and the reactive power-voltage sensitivity factor into the third expression, we obtain the reactive power demand; where the third expression is:

[0023]

[0024] Among them, Q 1,PV,need,t For reactive power demand, U 1,need,t For low voltage deviation gap, δ Q-U The reactive-voltage sensitivity factor Q 1,PV,need,t .

[0025] In one embodiment, the active power demand is obtained based on the low voltage deviation gap and the current reactive power output of the photovoltaic module, including:

[0026] Substituting the low voltage deviation gap, the current reactive power output of the photovoltaic modules, the active power-voltage sensitivity factor, and the reactive power-voltage sensitivity factor into the fourth expression, we obtain the active power demand; where the fourth expression is:

[0027]

[0028] Among them, P 1,PV,need,t For active power demand, U 1,need,t For low voltage deviation gap, δ Q-U Q is the reactive power-voltage sensitivity factor. PV,t For the current reactive power output of photovoltaic modules, δ P-U It is the active-voltage sensitive factor.

[0029] In one embodiment, the charging load shedding demand is obtained based on the low voltage deviation gap, the current reactive power output of the photovoltaic module, and the current active power output, including:

[0030] Substituting the low voltage deviation gap, the current reactive power output of the photovoltaic module, the current active power output of the photovoltaic module, the active power-voltage sensitivity factor, and the reactive power-voltage sensitivity factor into the fifth expression, the charging load shedding demand is obtained; where the fifth expression is:

[0031]

[0032] Among them, P 1,EV,need,t To cut off charging load demand, U 1,need,t For low voltage deviation gap, δ Q-U Q is the reactive power-voltage sensitivity factor. PV,t For the current reactive power output of photovoltaic modules, δ P-U For the active-voltage sensitivity factor, P PV,t It contributes to the current active power of photovoltaic modules.

[0033] Secondly, this application provides a voltage control device based on a charging station-photovoltaic system, comprising:

[0034] The low voltage deviation gap determination module is used to determine whether each node has a low voltage over-limit fault. If so, the node that triggered the low voltage over-limit fault is determined as the target node, and the low voltage deviation gap of the target node is determined.

[0035] The reactive power demand determination module is used to obtain the reactive power demand based on the low voltage deviation gap.

[0036] The first control module is used to control the photovoltaic modules to increase their reactive power output if the reactive power demand is less than or equal to the current maximum reactive power output of the photovoltaic modules in the power system; otherwise, it obtains the active power demand based on the low voltage deviation gap and the current reactive power output of the photovoltaic modules.

[0037] The second control module is used to increase the reactive power output and active power output of the photovoltaic modules according to the maximum reactive power supply and active power demand, respectively, if the active power demand is less than or equal to the current maximum active power supply of the photovoltaic modules in the power system; otherwise, it obtains the charging load cut-off demand based on the low voltage deviation gap, the current reactive power output and the current active power output of the photovoltaic modules.

[0038] The third control module is used to increase the reactive and active power output of the photovoltaic modules according to the maximum reactive power supply and the maximum active power supply, respectively, and to cut off the load of the charging station according to the charging load cut-off demand if the charging load cut-off demand is less than or equal to the current load of the charging station in the power system; otherwise, it increases the reactive and active power output of the photovoltaic modules according to the maximum reactive power supply and the maximum active power supply, respectively, and cuts off all the load of the charging station.

[0039] Thirdly, this application provides a computer device including one or more processors and a memory storing computer-readable instructions. When the computer-readable instructions are executed by one or more processors, they perform the steps of the voltage control method for the charging station-photovoltaic system in any of the above embodiments.

[0040] Fourthly, this application provides a storage medium storing computer-readable instructions, which, when executed by one or more processors, cause the one or more processors to perform the steps of the voltage control method for the charging station-photovoltaic system in any of the above embodiments.

[0041] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0042] The voltage control method in this embodiment first identifies the target node by real-time monitoring to determine if any node in the system is experiencing low voltage exceedance. Then, it calculates the reactive power demand based on the voltage gap at the target node and gradually attempts to compensate for the voltage gap based on the reactive and active power of the photovoltaic system. If photovoltaic regulation still cannot completely resolve the fault, it further calculates the load shedding demand and attempts to shed the charging station load to continue improving the voltage. Throughout the process, reactive power, active power, and load shedding are used sequentially, forming a hierarchical control system that coordinates various methods to address low-voltage faults in the power grid based on the characteristics of photovoltaic charging stations. This method fully utilizes the flexibility and feeding characteristics of charging piles and coordinates photovoltaic active and reactive power control for synergistic regulation. Based on the target node, it improves the overall node voltage of the 10kV distribution network to alleviate low-voltage problems. Furthermore, this strategy does not involve optimization solutions or model calculations, resulting in less computational pressure on the hardware and software and significantly improving regulation efficiency. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A schematic flowchart of a voltage control method based on a charging station-photovoltaic system provided in one embodiment of this application;

[0045] Figure 2 A schematic diagram of a voltage control device based on a charging station-photovoltaic system provided in one embodiment of this application;

[0046] Figure 3 This is an internal structural diagram of a computer device provided in one embodiment of this application. Detailed Implementation

[0047] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] This application provides a voltage control method based on a charging station-photovoltaic system. It is understood that the power system addressed in this application will include at least one photovoltaic charging station. The photovoltaic charging station includes multiple charging piles and photovoltaic modules. The power source for the charging piles can be the power grid or the photovoltaic modules. In addition to providing power to the charging piles, the photovoltaic modules can also charge local energy storage. Charging piles, as a new type of load, are often studied as an important control measure due to their flexible and adjustable characteristics and their ability to feed power to the grid in V2G mode. This application, based on the above architecture, utilizes the characteristics of the photovoltaic charging station to coordinate the control of photovoltaic modules and charging piles to manage low-voltage situations. Please refer to [link to relevant documentation]. Figure 1 The voltage control method includes steps S102 to S110.

[0049] S102, determine whether each node has a low voltage over-limit fault. If so, determine the node that triggered the low voltage over-limit fault as the target node and determine the low voltage deviation gap of the target node.

[0050] As can be understood, a node refers to a basic unit in the power system topology. Nodes are connected by lines to form the power system. A low-voltage over-limit fault refers to a node's voltage falling below the lower limit value specified by the power system. In a 10kV medium-voltage distribution network, this lower limit value can be set to 0.93 times the rated voltage. This implementation will continuously monitor low-voltage over-limit faults by continuously acquiring the real-time voltage values ​​of each node and comparing each real-time voltage value with the voltage lower limit value. When a node is found to have a low-voltage over-limit problem, it can be determined that the node has triggered a low-voltage over-limit fault. This node will be used as the target node. In this embodiment, the target node will be used as the object of voltage regulation. When the voltage of the target node rises above the voltage lower limit value, the entire system will be in a voltage healthy state. Therefore, after determining the target node, the low-voltage deviation gap will be determined based on the difference between the real-time voltage of the target node and the aforementioned voltage lower limit value. The low-voltage deviation gap reflects the difference between the current voltage of the target node and the voltage lower limit value.

[0051] S104, based on the low voltage deviation gap, obtain the reactive power demand.

[0052] Reactive power demand refers to the amount of reactive power required to correct the low voltage deviation shortfall at the target node. A larger low voltage deviation shortfall indicates a more severe voltage drop, requiring more reactive power support. There is a correlation between reactive power demand and the low voltage deviation shortfall; the amount of reactive power demand can be quantitatively assessed based on the size of the shortfall.

[0053] S106: If the reactive power demand is less than or equal to the current maximum reactive power output of the photovoltaic modules in the power system, then the photovoltaic modules are controlled to increase their reactive power output based on the reactive power demand. Otherwise, the active power demand is obtained based on the low voltage deviation gap and the current reactive power output of the photovoltaic modules.

[0054] It is understandable that one method of voltage regulation is through reactive power compensation. The reactive power output of a photovoltaic (PV) module refers to the reactive power it provides to the power system. In this embodiment, the PV modules in the PV charging station will be used as the reactive power provider. If the reactive power demand is less than or equal to the current maximum reactive power supply of the PV modules in the power system, it means that the reactive power margin of the PV modules themselves is sufficient to solve the low voltage limit problem. Therefore, the reactive power output of the PV modules will be directly controlled according to the reactive power demand to increase the voltage of the power system above the low voltage limit.

[0055] Otherwise, it indicates that the reactive power margin of the photovoltaic modules themselves is insufficient to solve the low voltage limit problem. Further increasing the active power output of the photovoltaic modules is necessary to resolve the voltage limit issue. Therefore, the contribution of the reactive power portion to the low voltage deviation gap will be assessed based on the current reactive power output of the photovoltaic modules. The remaining gap represents the portion of active power that needs to be addressed. The larger this remaining gap, the more active power support is required. There is a corresponding relationship between the active power demand and this remaining gap; based on the size of the gap, the amount of active power demand can be quantitatively assessed.

[0056] The maximum reactive power output of a photovoltaic (PV) module can be obtained from the difference between its rated reactive power and current reactive power output. The reactive power of the PV module can be controlled based on existing technologies.

[0057] S108: If the active power demand is less than or equal to the current maximum active power supply of the photovoltaic modules in the power system, then the reactive power output and active power output of the photovoltaic modules are increased according to the maximum reactive power supply and active power demand, respectively. Otherwise, the charging load shedding demand is obtained based on the low voltage deviation gap, the current reactive power output and the current active power output of the photovoltaic modules.

[0058] It is understandable that active power demand refers to the additional active power required from photovoltaic (PV) modules to correct the low-voltage deviation gap when PV reactive power is insufficient. The active power output of PV modules refers to the active power they provide to the power system. If the active power demand is less than or equal to the maximum active power output of the PV modules in the power system, it means that the total reactive power margin of the PV modules plus their active power margin is sufficient to solve the low-voltage limit problem. This will directly control the PV modules to increase their reactive power output to the maximum value, and further increase their active power output based on the active power demand, thereby raising the power system voltage above the low-voltage lower limit.

[0059] Otherwise, it indicates that the reactive and active power margins of the photovoltaic modules themselves are insufficient to resolve the low voltage deviation issue. Further reductions in the charging load of the photovoltaic charging stations are needed to potentially resolve the low voltage deviation problem. Therefore, we will assess the contribution of the reactive power portion to the low voltage deviation gap based on the current reactive power output of the photovoltaic modules, and assess the contribution of the active power portion to the low voltage deviation gap based on the current active power output of the photovoltaic modules. The remaining gap is the portion that needs to be addressed by load reduction. The larger this remaining gap, the more charging load needs to be cut. There is a corresponding relationship between the charging load and this remaining gap; depending on the size of the gap, the amount of charging load that needs to be cut can be quantitatively assessed.

[0060] The maximum active power output of a photovoltaic (PV) module can be obtained from the difference between its rated active power and current active power output. The active power of the PV module can be controlled using existing technologies.

[0061] S110: If the charging load shedding demand is less than or equal to the current load of the charging station in the power system, then the reactive power and active power output of the photovoltaic modules are increased according to the maximum reactive power supply and the maximum active power supply, respectively, and the load of the charging station is shedding according to the charging load shedding demand. Otherwise, the reactive power and active power output of the photovoltaic modules are increased according to the maximum reactive power supply and the maximum active power supply, respectively, and all loads of the charging station are shedding.

[0062] It can be understood that the charging load shedding demand refers to the amount of power of the charging pile load that needs to be cut off when the reactive and active power of the photovoltaic system still cannot meet the grid demand. If the charging load shedding demand is equal to or greater than the current load of the photovoltaic modules in the power system, it means that relying on the total reactive power margin of the photovoltaic modules plus the active power margin, plus cutting off part of the charging load, is sufficient to solve the low voltage limit problem. This will directly control the photovoltaic modules to increase their reactive power output to the maximum value, and cut off the charging load according to the charging load shedding demand, so as to raise the voltage of the power system above the low voltage limit.

[0063] Otherwise, it indicates that the regulation capabilities of photovoltaic modules and charging piles are insufficient to solve the low voltage over-limit problem, and other means in the power system are needed to assist in regulation. Photovoltaic modules and charging piles will provide the greatest support for this, namely, increasing the reactive and active power outputs of photovoltaic modules according to the maximum reactive and active power outputs, respectively, and cutting off all loads of the charging station to maximize the system voltage.

[0064] The voltage control method in this embodiment first identifies the target node by real-time monitoring to determine if any node in the system is experiencing low voltage exceedance. Then, it calculates the reactive power demand based on the voltage gap at the target node and gradually attempts to compensate for the voltage gap based on the reactive and active power of the photovoltaic system. If photovoltaic regulation still cannot completely resolve the fault, it further calculates the load shedding demand and attempts to shed the charging station load to continue improving the voltage. Throughout the process, reactive power, active power, and load shedding are used sequentially, forming a hierarchical control system that coordinates various methods to address low-voltage faults in the power grid based on the characteristics of photovoltaic charging stations. This method fully utilizes the flexibility and feeding characteristics of charging piles and coordinates photovoltaic active and reactive power control for synergistic regulation. Based on the target node, it improves the overall node voltage of the 10kV distribution network to alleviate low-voltage problems. Furthermore, this strategy does not involve optimization solutions or model calculations, resulting in less computational pressure on the hardware and software and significantly improving regulation efficiency.

[0065] In one embodiment, the voltage control method based on charging station-photovoltaics further includes:

[0066] (1) Obtain the active power offset, reactive power offset and voltage offset of each node in the power system in each acquisition interval of the previous preset period.

[0067] It can be understood that active power offset, reactive power offset, and voltage offset refer to the changes in active power, reactive power, and voltage at each node within a sampling interval, respectively. The power system collects the active power, reactive power, and voltage data of each node at each sampling moment; the time difference between sampling moments is the sampling interval. Two adjacent sampling moments constitute a sampling interval. By subtracting the data from the previous sampling moment from the data obtained at the later sampling moment, the change corresponding to the sampling interval formed by these two adjacent sampling moments can be obtained. The preset period is the period for analyzing and monitoring the operation of the power system, generally in days. Here, the purpose is to analyze the impact of active and reactive power changes on voltage by analyzing the active power offset, reactive power offset, and voltage offset at each sampling interval, providing data support for subsequent processing.

[0068] (2) Based on each active power offset and voltage offset, the active power-voltage sensitivity factor is obtained, and based on each reactive power offset and voltage offset, the reactive power-voltage sensitivity factor is obtained. Among them, the active power-voltage sensitivity factor is used to determine the active power demand and the charging load shedding demand, and the reactive power-voltage sensitivity factor is used to determine the reactive power demand, active power demand, and charging load shedding demand.

[0069] It is understandable that the active power-voltage sensitivity factor reflects the degree to which changes in the active power of the power system affect voltage changes. The reactive power-voltage sensitivity factor reflects the degree to which changes in the reactive power of the power system affect voltage changes. Both active power demand and charging load shedding demand are related to the active power output of photovoltaic (PV) modules, and their impact on voltage needs to be determined during calculations. Therefore, the active power-voltage sensitivity factor is an important parameter in calculating both active power demand and charging load shedding demand. Furthermore, the aforementioned reactive power demand, active power demand, and charging load shedding demand are all related to the current reactive power output of PV modules, and their impact on voltage needs to be determined during calculations. Therefore, the reactive power-voltage sensitivity factor is an important parameter in calculating reactive power demand, active power demand, and charging load shedding demand.

[0070] In one embodiment, an active power-voltage sensitivity factor is obtained based on each active power offset and voltage offset, including:

[0071] Substituting the active power offset and voltage offset into the first expression, we obtain the active power-voltage sensitivity factor. The first expression is:

[0072]

[0073] Where, δ P-U The active power-voltage sensitivity factor is denoted by n, where n is the total number of nodes, T is the total number of times active power offset, reactive power offset, and voltage offset are collected, and ΔU is the voltage-voltage sensitivity factor. i,t Let ΔP be the voltage offset of the i-th node between acquisition time t and acquisition time t-1. i,t Let be the active power offset of the i-th node between acquisition time t and acquisition time t-1. It can be understood that in this embodiment, the active power-voltage sensitivity factor requires calculating the ratio between the voltage offset and the active power offset for each node in each acquisition interval, summing all ratios, and averaging them. The resulting average value is the active power-voltage sensitivity factor.

[0074] In one embodiment, a reactive power-voltage sensitivity factor is obtained based on each reactive power offset and voltage offset, including:

[0075] Substituting the reactive power offset and voltage offset into the second expression, we obtain the reactive power-voltage sensitivity factor. The second expression is:

[0076]

[0077] Where, δ Q-U Here, ΔU is the reactive power-voltage sensitivity factor, n is the total number of nodes, T is the total number of times when active power offset, reactive power offset, and voltage offset are collected, and ΔU is the reactive power-voltage sensitivity factor. i,t Let ΔQ be the voltage offset of the i-th node between acquisition time t and acquisition time t-1. i,t Let be the reactive power offset of the i-th node between acquisition time t and acquisition time t-1. It can be understood that in this embodiment, the reactive power-voltage sensitivity factor requires calculating the ratio between the voltage offset and reactive power offset for each node in each acquisition interval, summing all ratios, and averaging them. The resulting average value is the reactive power-voltage sensitivity factor.

[0078] In one embodiment, the reactive power demand is obtained based on the low voltage deviation gap, including:

[0079] Substituting the low voltage deviation gap and the reactive power-voltage sensitivity factor into the third expression, we obtain the reactive power demand. The third expression is:

[0080]

[0081] Among them, Q 1,PV,need,t For reactive power demand, U 1,need,t For low voltage deviation gap, δ Q-U The reactive-voltage sensitivity factor Q 1,PV,need,t .

[0082] In one embodiment, the active power demand is obtained based on the low voltage deviation gap and the current reactive power output of the photovoltaic module, including:

[0083] Substituting the low voltage deviation gap, the current reactive power output of the photovoltaic modules, the active power-voltage sensitivity factor, and the reactive power-voltage sensitivity factor into the fourth expression, we obtain the active power demand. The fourth expression is:

[0084]

[0085] Among them, P 1,PV,need,t For active power demand, U 1,need,t For low voltage deviation gap, δ Q-U Q is the reactive power-voltage sensitivity factor. PV,t For the current reactive power output of photovoltaic modules, δ P-U It is the active-voltage sensitive factor.

[0086] In one embodiment, the charging load shedding demand is obtained based on the low voltage deviation gap, the current reactive power output of the photovoltaic module, and the current active power output, including:

[0087] Substituting the low voltage deviation gap, the current reactive power output of the photovoltaic module, the current active power output of the photovoltaic module, the active power-voltage sensitivity factor, and the reactive power-voltage sensitivity factor into the fifth expression, the charging load shedding demand is obtained. The fifth expression is:

[0088]

[0089] Among them, P 1,EV,need,t To cut off charging load demand, U 1,need,t For low voltage deviation gap, δ Q-U Q is the reactive power-voltage sensitivity factor. PV,t For the current reactive power output of photovoltaic modules, δ P-U For the active-voltage sensitivity factor, P PV,t It contributes to the current active power of photovoltaic modules.

[0090] This application provides a voltage control device based on a charging station-photovoltaic system. Please refer to [link / reference]. Figure 2 ,include:

[0091] The low voltage deviation gap determination module 210 is used to determine whether each node has a low voltage over-limit fault. If so, the node that triggered the low voltage over-limit fault is determined as the target node, and the low voltage deviation gap of the target node is determined.

[0092] The reactive power demand determination module 220 is used to obtain the reactive power demand based on the low voltage deviation gap.

[0093] The first control module 230 is used to control the photovoltaic modules to increase their reactive power output if the reactive power demand is less than or equal to the current maximum reactive power output of the photovoltaic modules in the power system. Otherwise, it calculates the active power demand based on the low voltage deviation gap and the current reactive power output of the photovoltaic modules.

[0094] The second control module 240 is used to increase the reactive power output and active power output of the photovoltaic modules based on the maximum reactive power supply and active power demand, respectively, if the active power demand is less than or equal to the current maximum active power supply of the photovoltaic modules in the power system. Otherwise, it calculates the charging load shedding demand based on the low voltage deviation gap, the current reactive power output and the current active power output of the photovoltaic modules.

[0095] The third control module 250 is used to, if the charging load shedding demand is less than or equal to the current load of the charging station in the power system, increase the reactive power and active power output of the photovoltaic modules according to the maximum reactive power supply and the maximum active power supply, respectively, and shed the load of the charging station according to the charging load shedding demand. Otherwise, it increases the reactive power and active power output of the photovoltaic modules according to the maximum reactive power supply and the maximum active power supply, respectively, and sheds all the load of the charging station.

[0096] Specific limitations regarding the voltage control device based on charging station-photovoltaics can be found in the above-described limitations of the voltage control method based on charging station-photovoltaics, and will not be repeated here. Each module in the aforementioned voltage control device based on charging station-photovoltaics can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module. It should be noted that the module division in this embodiment is illustrative and only represents a logical functional division; other division methods may be used in actual implementation.

[0097] This application provides a computer device including one or more processors and a memory storing computer-readable instructions. When executed by one or more processors, the computer-readable instructions perform the steps of the voltage control method for a charging station-photovoltaic system in any of the above embodiments.

[0098] Indicatively, such as Figure 3 As shown, Figure 3 This is a schematic diagram of the internal structure of a computer device provided in an embodiment of this application. (Refer to...) Figure 3 The computer device 300 includes a processing component 302, which further includes one or more processors, and memory resources represented by memory 301 for storing instructions, such as application programs, that can be executed by the processing component 302. The application programs stored in memory 301 may include one or more modules, each corresponding to a set of instructions. Furthermore, the processing component 302 is configured to execute instructions to perform the steps of the voltage control method for the charging station-photovoltaic system described in any of the above embodiments.

[0099] The computer device 300 may also include a power supply component 303 configured to perform power management of the computer device 300, a wired or wireless network interface 304 configured to connect the computer device 300 to a network, and an input / output (I / O) interface 305.

[0100] Those skilled in the art will understand that Figure 3 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0101] This application provides a storage medium storing computer-readable instructions, which, when executed by one or more processors, cause the one or more processors to perform the steps of the voltage control method for the charging station-photovoltaic system in any of the above embodiments.

[0102] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0103] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A voltage control method based on a charging station-photovoltaic system, characterized in that, include: Determine whether each node has a low voltage over-limit fault. If so, identify the node that triggered the low voltage over-limit fault as the target node and determine the low voltage deviation gap of the target node. Based on the aforementioned low voltage deviation gap, the reactive power demand is obtained; If the reactive power demand is less than or equal to the current maximum reactive power supply of the photovoltaic modules in the power system, then the photovoltaic modules are controlled to increase their reactive power output based on the reactive power demand; otherwise, the active power demand is obtained based on the low voltage deviation gap and the current reactive power output of the photovoltaic modules. If the active power demand is less than or equal to the current maximum active power supply of the photovoltaic modules in the power system, then the reactive power output and active power output of the photovoltaic modules are increased according to the maximum reactive power supply and the active power demand, respectively. Otherwise, based on the low voltage deviation gap, the current reactive power output and the current active power output of the photovoltaic module, the charging load cut-off demand is obtained; If the charging load cut-off demand is less than or equal to the current load of the charging station in the power system, then the reactive power output and active power output of the photovoltaic module are increased according to the maximum reactive power supply and the maximum active power supply, respectively, and the load of the charging station is cut off according to the charging load cut-off demand. Otherwise, the reactive power and active power output of the photovoltaic modules are increased according to the maximum reactive power supply and the maximum active power supply, respectively, and all loads of the charging station are cut off.

2. The voltage control method based on charging station-photovoltaic as described in claim 1, characterized in that, Before determining whether a low-voltage over-limit fault has occurred at each node, the following steps are also included: The active power offset, reactive power offset, and voltage offset of each node in the power system are obtained in each acquisition interval of the previous preset cycle. Based on the active power offset and the voltage offset, an active power-voltage sensitivity factor is obtained, and based on the reactive power offset and the voltage offset, a reactive power-voltage sensitivity factor is obtained; wherein, the active power-voltage sensitivity factor is used to determine the active power demand and the charging load shedding demand, and the reactive power-voltage sensitivity factor is used to determine the reactive power demand, the active power demand, and the charging load shedding demand.

3. The voltage control method based on charging station-photovoltaic as described in claim 2, characterized in that, The process of obtaining the active power-voltage sensitivity factor based on the active power offset and the voltage offset includes: Substituting the active power offset and the voltage offset into the first expression, the active power-voltage sensitivity factor is obtained; wherein, the first expression is: Where, δ P-U Let be the active power-voltage sensitivity factor, n be the total number of nodes, T be the total number of times the active power offset, reactive power offset, and voltage offset are collected, and ΔU be the voltage sensitivity factor. i,t Let ΔP be the voltage offset of the i-th node between acquisition time t and acquisition time t-1. i,t The active power offset of the i-th node between acquisition time t and acquisition time t-1.

4. The voltage control method based on charging station-photovoltaic as described in claim 2, characterized in that, The process of obtaining the reactive power-voltage sensitivity factor based on the reactive power offset and the voltage offset includes: Substituting the reactive power offset and the voltage offset into the second expression, the reactive power-voltage sensitivity factor is obtained; wherein, the second expression is: Where, δ Q-U Let be the reactive power-voltage sensitivity factor, n be the total number of nodes, T be the total number of times the active power offset, reactive power offset, and voltage offset are collected, and ΔU be the voltage sensitivity factor. i,t Let ΔQ be the voltage offset of the i-th node between acquisition time t and acquisition time t-1. i,t The reactive power offset of the i-th node between acquisition time t and acquisition time t-1.

5. The voltage control method based on charging station-photovoltaic as described in claim 2, characterized in that, The process of obtaining the reactive power demand based on the low voltage deviation gap includes: Substituting the low voltage deviation gap and the reactive power-voltage sensitivity factor into the third expression, the reactive power demand is obtained; wherein, the third expression is: Among them, Q 1,PV,need,t U represents the reactive power demand. 1,need,t For the low voltage deviation gap, δ Q-U The reactive-voltage sensitivity factor Q 1,PV,need,t .

6. The voltage control method based on charging station-photovoltaic as described in claim 2, characterized in that, The process of obtaining the active power demand based on the low voltage deviation gap and the current reactive power output of the photovoltaic module includes: Substituting the low voltage deviation gap, the current reactive power output of the photovoltaic module, the active power-voltage sensitivity factor, and the reactive power-voltage sensitivity factor into the fourth expression, the active power demand is obtained; wherein, the fourth expression is: Among them, P 1,PV,need,t For the stated active power demand, U 1,need,t For the low voltage deviation gap, δ Q-U Let Q be the reactive power-voltage sensitivity factor. PV,t δ represents the current reactive power output of the photovoltaic module. P-U The active-voltage sensitivity factor is mentioned above.

7. The voltage control method based on charging station-photovoltaic as described in claim 2, characterized in that, The step of obtaining the charging load shedding demand based on the low voltage deviation gap, the current reactive power output, and the current active power output of the photovoltaic module includes: Substituting the low voltage deviation gap, the current reactive power output of the photovoltaic module, the current active power output of the photovoltaic module, the active power-voltage sensitivity factor, and the reactive power-voltage sensitivity factor into the fifth expression, the charging load shedding demand is obtained; wherein, the fifth expression is: Among them, P 1,EV,need,t U is the amount of charging load cut-off required. 1,need,t For the low voltage deviation gap, δ Q-U Let Q be the reactive power-voltage sensitivity factor. PV,t δ represents the current reactive power output of the photovoltaic module. P-U For the active-voltage sensitivity factor, P PV,t This refers to the current active power output of the photovoltaic module.

8. A voltage control device based on a charging station-photovoltaic system, characterized in that, include: The low voltage deviation gap determination module is used to determine whether each node has a low voltage over-limit fault. If so, the node that triggered the low voltage over-limit fault is determined as the target node, and the low voltage deviation gap of the target node is determined. The reactive power demand determination module is used to obtain the reactive power demand based on the low voltage deviation gap. The first control module is used to control the photovoltaic module to increase its reactive power output according to the reactive power demand if the reactive power demand is less than or equal to the current maximum reactive power supply of the photovoltaic module in the power system. Otherwise, the active power demand is obtained based on the low voltage deviation gap and the current reactive power output of the photovoltaic module; The second control module is used to increase the reactive power output and active power output of the photovoltaic module according to the maximum reactive power supply and the active power demand, respectively, if the active power demand is less than or equal to the current maximum active power supply of the photovoltaic module in the power system. Otherwise, based on the low voltage deviation gap, the current reactive power output and the current active power output of the photovoltaic module, the charging load cut-off demand is obtained; The third control module is used to increase the reactive power and active power output of the photovoltaic module according to the maximum reactive power supply and the maximum active power supply respectively, and to cut off the load of the charging station according to the charging load cut-off demand if the charging load cut-off demand is less than or equal to the current load of the charging station in the power system. Otherwise, the reactive power and active power output of the photovoltaic modules are increased according to the maximum reactive power supply and the maximum active power supply, respectively, and all loads of the charging station are cut off.

9. A computer device, characterized in that, It includes one or more processors and a memory storing computer-readable instructions, which, when executed by the one or more processors, perform the steps of the voltage control method for a charging station-photovoltaic system as described in any one of claims 1-7.

10. A storage medium, characterized in that, The storage medium stores computer-readable instructions that, when executed by one or more processors, cause the one or more processors to perform the steps of the voltage control method for a charging station-photovoltaic system as described in any one of claims 1-7.

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