Method, device and system for temporary stability control of photovoltaic charging station participating in power grid

Abstract

The present invention discloses a method, device and system for temporary stabilization control of photovoltaic and storage charging stations participating in a power grid. The method comprises: calculating a distribution factor table of each photovoltaic and storage charging station for each expected fault set in advance; when a fault occurs in the power grid, obtaining the distribution factor of each photovoltaic and storage charging station corresponding to the fault; implementing a corresponding control strategy based on the relative size of the distribution factor of each photovoltaic and storage charging station and a threshold; and incorporating the photovoltaic and storage charging stations into a temporary stabilization control resource pool of the power grid, thereby reducing the cost of traditional emergency control strategies such as machine shedding and load shedding.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and in particular to a method, device and system for controlling temporary stability of a photovoltaic charging station participating in a power grid. Background Art

[0002] With the increasing use of electric vehicles, the development of electric vehicles requires the deployment of corresponding charging stations within certain areas to charge electric vehicles and replenish their power. In particular, photovoltaic charging stations, which can comprehensively utilize photovoltaic power generation, grid power supply, and energy storage systems to charge electric vehicles, are widely used because they can convert and store light energy, making them more energy-efficient and environmentally friendly. Currently, fast charging stations based on non-onboard DC charging technology with high charging power and short service time, while bringing a convenient experience to electric vehicle users, may also cause problems such as insufficient distribution network capacity, voltage drops, and reduced frequency. In addition, the drastic changes in power at the moment of starting and stopping fast charging stations also pose a huge challenge to the real-time balance and stable control of the power grid. Summary of the Invention

[0003] The embodiments of the present application aim to reduce the cost of traditional emergency control strategies such as power outages and load shedding by providing a method, device, and system for temporary stability control of a photovoltaic charging station participating in a power grid.

[0004] An embodiment of the present application provides a method for controlling the temporary stability of a power grid by a photovoltaic power station with energy storage, the method comprising:

[0005] When a power grid fault occurs, determining a distribution factor for each solar-powered charging station associated with the fault, wherein each distribution factor is a ratio of a participation factor of a power source electrically closest to the corresponding solar-powered charging station under the fault to the electrical distance between the power source and the corresponding solar-powered charging station;

[0006] Comparing the distribution factor of each of the solar-energy storage charging stations with a preset value, and determining a control strategy for each of the solar-energy storage charging stations based on the comparison result;

[0007] According to the control strategy, each of the solar-powered charging stations is controlled to operate.

[0008] Optionally, the step of comparing the distribution factor of each of the solar-energy storage charging stations with a preset value and determining the control strategy of each of the solar-energy storage charging stations according to the comparison result includes:

[0009] Comparing the distribution factor of each of the solar-storage charging stations with the first preset value or the second preset value to obtain a comparison result;

[0010] Determine the group to which each of the solar-storage charging stations belongs based on the comparison results;

[0011] Determine the control strategy of each of the photovoltaic charging stations in the group.

[0012] Optionally, the group includes a leading group or a remaining group; and the step of determining the group to which each of the solar-storage charging stations belongs based on the comparison result includes:

[0013] If the distribution factor of the solar-energy storage charging station is greater than the first preset value, it is determined that the corresponding solar-energy storage charging station is located in the leading group; or

[0014] If the distribution factor of the solar-powered charging station is less than the second preset value, it is determined that the corresponding solar-powered charging station is located in the remaining group, and the second preset value is less than the first preset value.

[0015] Optionally, the step of determining the control strategy of each of the solar-energy storage charging stations in the group includes:

[0016] When the group is the leading group, determining the first control strategy as the control strategy of each photovoltaic charging station in the leading group; or,

[0017] When the group is the remaining group, the second control strategy is determined to be the control strategy of each photovoltaic charging station in the remaining group.

[0018] Optionally, the first control strategy includes: increasing the charging power of each photovoltaic charging station in the leading group, that is, controlling the energy storage module to operate in a charging mode and controlling the photovoltaic module to operate in a reactive power mode;

[0019] Alternatively, the second control strategy includes: reducing the charging power of each photovoltaic charging station in the remaining group, that is, controlling the energy storage module to operate in a discharge mode and controlling the photovoltaic module to operate in a maximum power point tracking mode.

[0020] Optionally, before the step of determining the distribution factors of the photovoltaic charging stations associated with the fault when a fault occurs in the power grid, the step includes:

[0021] Determine the expected fault set based on the power grid topology;

[0022] Calculating a distribution factor of each photovoltaic charging station within the power grid topology based on the anticipated faults in the anticipated fault set;

[0023] A distribution factor table of the photovoltaic charging stations corresponding to the expected fault is generated according to the distribution factors of the photovoltaic charging stations.

[0024] Optionally, the step of calculating the distribution factor of each photovoltaic charging station within the power grid topology based on the expected fault in the expected fault set includes:

[0025] Obtaining the electrical distance between each of the photovoltaic charging stations and each power source in the grid topology under the expected fault;

[0026] Determine the power source closest to the corresponding solar-storage charging station based on the electrical distance;

[0027] determining a participation factor of the power source that is electrically closest;

[0028] The distribution factor of each of the photovoltaic charging stations within the grid topology under the expected fault is determined according to the participation factor and the ratio of the electrical distance between the photovoltaic charging station and the power source closest to the photovoltaic charging station.

[0029] Optionally, when a power grid fault occurs, the step of determining the distribution factor of each photovoltaic charging station associated with the fault includes:

[0030] When a fault occurs in the power grid, a distribution factor table of photovoltaic charging stations corresponding to the fault is determined;

[0031] The distribution factors in the photovoltaic charging station distribution factor table are determined as the distribution factors of each photovoltaic charging station associated with the fault.

[0032] In addition, to achieve the above-mentioned purpose, the present invention also provides a temporary stability control device for a photovoltaic storage charging station participating in a power grid, comprising: a memory, a processor, and a temporary stability control program for a photovoltaic storage charging station participating in a power grid stored in the memory and runnable on the processor. When the temporary stability control program for a photovoltaic storage charging station participating in a power grid is executed by the processor, the steps of the above-mentioned temporary stability control method for a photovoltaic storage charging station participating in a power grid are implemented.

[0033] In addition, to achieve the above-mentioned purpose, the present invention also provides a solar energy storage charging system, comprising:

[0034] At least two photovoltaic and storage charging stations; and a temporary stability control device for the photovoltaic and storage charging stations to participate in the power grid.

[0035] The embodiments of the present application provide a technical solution for a method, device, and system for temporary stabilization control of a power grid in which a photovoltaic and storage charging station participates. Since a distribution factor table of each photovoltaic and storage charging station is calculated in advance for each expected fault set, when a power grid fault occurs, the distribution factor of each photovoltaic and storage charging station corresponding to the fault is obtained; a corresponding control strategy is implemented based on the relative size of the distribution factor of each photovoltaic and storage charging station and a threshold; and the photovoltaic and storage charging station is incorporated into the temporary stabilization control resource pool of the power grid, reducing the cost of traditional emergency control strategies such as machine shedding and load shedding. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a flow chart of a first embodiment of a method for controlling temporary stability of a power grid in which a photovoltaic charging station participates in the present invention;

[0037] Figure 2 This is a flow chart of a second embodiment of the method for controlling temporary stability of a solar-powered charging station participating in a power grid according to the present invention;

[0038] Figure 3 This is a schematic diagram of the structure of the temporary stability control device of the photovoltaic storage charging station participating in the power grid of the present invention.

[0039] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. The above-mentioned drawings are only an embodiment diagram, not the entire invention. DETAILED DESCRIPTION

[0040] Currently, during emergency control strategies such as generator or load shedding, charging and discharging power can fluctuate dramatically, leading to unstable grid power supply. To reduce the cost of traditional emergency control strategies like generator or load shedding, this application proposes a method for temporarily stabilizing the grid by incorporating photovoltaic (PV) and energy storage charging stations. This method can provide temporary stabilization control for the grid during generator or load shedding. Specifically, this application performs simulation calculations based on a set of faults in the grid to determine the distribution factors of each PV and energy storage charging station within the grid corresponding to each anticipated fault. Once a fault occurs in the grid, the distribution factors of each PV and energy storage charging station are retrieved from a table, and differentiated control strategies are implemented based on the differences in distribution factors. During the control process, for PV and energy storage charging stations with higher distribution factors, located in the leading cluster under the grid fault, the charging power of the PV and energy storage charging stations should be increased, with the energy storage modules operating in charging mode and the photovoltaic modules operating in reactive power mode. For PV and energy storage charging stations with lower distribution factors, located in the remaining cluster under the grid fault, the charging power of the PV and energy storage charging stations should be reduced, with the energy storage modules operating in discharging mode and the photovoltaic modules operating in MPPT mode. Because differentiated control strategies can be implemented based on the differences in the distribution factors of solar-powered storage charging stations, this application utilizes the aforementioned temporary stabilization control method. Based on the topological location of the solar-powered storage fast charging station in the distribution network and the fault conditions, the operating mode of the solar-powered storage fast charging station is adaptively adjusted, thereby reducing the cost of emergency control strategies such as generator and load shedding.

[0041] To better understand the above technical solutions, exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0042] like Figure 1 As shown, in the first embodiment of the present application, the method for controlling the temporary stability of the power grid by the photovoltaic charging station of the present application includes the following steps:

[0043] Step S110: When a fault occurs in the power grid, a distribution factor of each photovoltaic charging station associated with the fault is determined.

[0044] In this embodiment, the power grid refers to the power grid that receives electricity from the transmission grid or regional power plants and distributes it locally or in a tiered manner according to voltage to various users through distribution facilities. The power grid is used to provide electricity to photovoltaic charging stations for charging electric vehicles. These photovoltaic charging stations are also called integrated photovoltaic and energy storage charging stations. These photovoltaic and energy storage charging stations can also charge electric vehicles using photovoltaic modules and energy storage modules. These integrated photovoltaic and energy storage charging stations can be fast-charging stations that can quickly charge electric vehicles, or they can be standard integrated photovoltaic and energy storage charging stations.

[0045] Whether the power supply is from the grid, a PV charging station, or a combination of the grid and PV charging stations, unstable power supply will occur during the startup and shutdown of the PV charging station. This application uses the example of controlling the temporary stability of the grid by PV charging stations during the startup and shutdown of the grid as an example.

[0046] In this embodiment, when a grid fault occurs, a distribution factor table of solar-powered charging stations associated with the fault is obtained. Each type of fault has a corresponding distribution factor table. This table includes the distribution factor corresponding to each solar-powered charging station under the current grid topology.

[0047] The grid topology includes multiple photovoltaic charging stations, a power source, and a connection between each photovoltaic charging station and the corresponding power source. The power source is a synchronous generator. Each grid topology has a corresponding fault set, which includes the faults that may occur under the grid topology. Optionally, a fault set for each grid topology can be pre-set; for each fault in the fault set, the distribution factor of each photovoltaic charging station in the grid is calculated separately to form a photovoltaic charging station distribution factor table corresponding to each fault; if a fault occurs in the grid, the distribution factor of each photovoltaic charging station corresponding to the fault can be obtained by looking up the table.

[0048] The fault in the power grid can be a three-phase permanent short circuit fault, a single-phase permanent short circuit fault, a three-phase disconnection fault, or other faults. For example, when a three-phase permanent short circuit fault is detected in the power grid, a table can be consulted to obtain the distribution factors of each solar-to-storage charging station associated with the three-phase permanent short circuit fault.

[0049] In this embodiment, the distribution factor of the photovoltaic charging station is used to characterize the position of the photovoltaic charging station in the grid topology when a fault occurs in the grid. In addition to being determined in advance based on the grid topology, the distribution factor of the photovoltaic charging station can also be determined during actual use. Specifically, the distribution factor of each photovoltaic charging station in the photovoltaic charging station distribution factor table is essentially the ratio of the participation factor of the power source closest to the photovoltaic charging station under the fault and the electrical distance of the power source. The formula can be used Calculate the distribution factor of each solar-storage charging station, where P j is the participation factor of the power source j that is closest to the solar storage charging station i in terms of electrical distance; d ij is the electrical distance between solar-powered charging station i and its nearest power source j. Specifically, given the current grid topology, since the electrical distance between each power source and the solar-powered charging station is different, the electrical distance between each power source and the solar-powered charging station can be calculated. The participation factor of the power source closest to the solar-powered charging station is then selected, along with the electrical distance between the closest power source and the solar-powered charging station, to calculate the distribution factor for the solar-powered charging station. Since the grid topology contains multiple solar-powered charging stations, the distribution factor for each solar-powered charging station can be calculated using the above method. This generates a table of solar-powered charging station distribution factors associated with the fault.

[0050] Among them, electrical distance refers to the air gap distance with a very low probability of discharge between live parts or between live parts and grounded parts during live work.

[0051] Among them, according to the operating mode of the photovoltaic storage charging station and the corresponding model parameters, the time domain simulation method is used to calculate the operating trajectory of the photovoltaic storage charging station under the current fault; based on the time domain simulation calculation of the fault, EEAC analysis is used to obtain quantitative information on transient power angle stability, including generator grouping (leading group and remaining group), margin and swing order.

[0052] The participation factor of the power supply of the present application is the generator participation factor. Specifically, for the identification of the generator participation factor in the transient power angle stability generator grouping mode, if the transient power angle stability margin is less than 0, for the leading group generators, calculate the acceleration kinetic energy of each generator in the leading group when the disturbed trajectory passes through the dynamic saddle point (DSP), take the maximum value of the acceleration kinetic energy of the generators in the leading group as the benchmark, and take the ratio of the acceleration kinetic energy of each generator in the leading group to the benchmark value as the participation factor of each generator; for the remaining group generators, calculate the deceleration kinetic energy of each generator in the remaining group when the disturbed trajectory passes through the DSP, also take the maximum value of the acceleration kinetic energy of the generators in the leading group as the benchmark, and take the ratio of the deceleration kinetic energy of each generator in the remaining group to the benchmark value. The inverse of is used as the participation factor of each generator; if the transient power angle stability margin is greater than or equal to 0, for the leading group generators, we must first determine the moment when the acceleration kinetic energy of the equivalent generators in the leading group in the swing order given by the disturbed trajectory in the stable mode reaches the maximum value, and take the maximum value of the acceleration kinetic energy of the generators in the leading group at that moment as the benchmark, and take the ratio of the acceleration kinetic energy of each generator in the leading group at that moment to the benchmark value as the participation factor of each generator; for the remaining group generators, similarly take the maximum value of the acceleration kinetic energy of the generators in the leading group at that moment as the benchmark, and take the inverse of the ratio of the deceleration kinetic energy of each generator in the remaining group at that moment to the benchmark value as the participation factor of each generator.

[0053] Step S120 , comparing the distribution factor of each of the solar-energy storage charging stations with a preset value, and determining a control strategy corresponding to each of the solar-energy storage charging stations according to the comparison result.

[0054] In this embodiment, after determining the distribution factors of each PV-storage charging station associated with a fault, the stations can be grouped. Groups include a leading group and a remaining group. PV-storage charging stations with higher distribution factors are located within the leading group affected by the grid fault. PV-storage charging stations with lower distribution factors are located within the remaining group affected by the grid fault. The preset value can be set based on actual conditions, for example, based on the current grid topology; alternatively, the preset value can be set for different groups.

[0055] Optionally, the distribution factor of each solar-powered charging station can be compared with a first preset value or a second preset value to obtain a comparison result. The first preset value is greater than the second preset value. If the distribution factor of a solar-powered charging station is greater than the first preset value, the solar-powered charging station is determined to be in the leading cluster. If the distribution factor of a solar-powered charging station is less than the second preset value, the solar-powered charging station is determined to be in the remaining cluster. This allows the cluster to be determined for each solar-powered charging station in the event of a fault.

[0056] Step S130: Control the operation of each of the solar-powered charging stations according to the corresponding control strategy.

[0057] In this embodiment, each group has a corresponding control strategy, which can be used to control the operation of the solar-powered charging stations in each group.

[0058] Optionally, when the group is a leading group, a first control strategy is determined as the control strategy for each solar-powered charging station in the leading group, and each solar-powered charging station in the leading group is controlled to operate based on the first control strategy. When the group is a remaining group, a second control strategy is determined as the control strategy for each solar-powered charging station in the remaining group, and each solar-powered charging station in the remaining group is controlled to operate based on the second control strategy.

[0059] Specifically, differentiated control strategies are implemented based on the differences in the distribution factors of the photovoltaic and storage charging stations. For photovoltaic and storage charging stations with higher distribution factors, which are located in the leading cluster under grid fault conditions, the first control strategy is to increase the charging power of the photovoltaic and storage charging stations, operate the energy storage modules in charging mode, and operate the photovoltaic modules in reactive power mode (generating reactive power). For photovoltaic and storage charging stations with lower distribution factors, which are located in the remaining cluster under anticipated grid fault conditions, the second control strategy is to reduce the charging power of the photovoltaic and storage charging stations, operate the energy storage modules in discharge mode, and operate the photovoltaic modules in MPPT mode (both photovoltaic and storage provide power to the charging stations).

[0060] For example, ε1 (first preset value) and ε2 (second preset value) are preset thresholds, and ε1>ε2>0. There are the following two cases:

[0061] If f i >ε1 (i.e. the PV-storage charging station is located at the leading group under the fault), the ability to absorb electric energy from the leading group under the fault should be increased, that is, the charging power of the PV-storage charging station should be increased, the energy storage module should be operated in charging mode, and the photovoltaic module should be operated in reactive power mode (generating reactive power). According to the formula Since the photovoltaic modules generate reactive power, the terminal voltage of the leading group of units increases under the fault, so the output active power of the leading group of units increases under the fault, causing the photovoltaic charging station to consume more active power from the power source closest to it electrically.

[0062] If f i <ε2 (i.e., if the photovoltaic storage charging station is located at the position of the remaining group under the fault), the charging power of the photovoltaic storage charging station is reduced, and the photovoltaic storage charging station can even provide power for the remaining group units under the fault, operate the energy storage module in the discharge mode, and operate the photovoltaic module in the MPPT mode (both photovoltaic and storage provide power to the charging station), so that the photovoltaic storage charging station consumes less active power from the power source closest to it electrically, and can even provide power for the remaining group units under the fault, reducing the output active power of the remaining group units.

[0063] According to the above technical solution, once a fault occurs in the power grid, the distribution factors of each photovoltaic charging station are obtained by looking up the table, and differentiated control strategies are implemented according to the differences in the distribution factors. During the control process, for photovoltaic charging stations with higher distribution factors, which are located in the leading group under the power grid fault, the charging power of the photovoltaic charging station should be increased, the energy storage module should be operated in the charging mode, and the photovoltaic module should be operated in the reactive power mode; for photovoltaic charging stations with lower distribution factors, which are located in the remaining group under the power grid fault, the charging power of the photovoltaic charging station should be reduced, the energy storage module should be operated in the discharge mode, and the photovoltaic should be operated in the MPPT mode. Because differentiated control strategies can be implemented based on the differences in the distribution factors of photovoltaic charging stations. Precisely because this application adopts the above-mentioned temporary stabilization control method, the operation mode of the photovoltaic charging station is adaptively adjusted according to the topological position of the photovoltaic charging station in the power grid and the fault situation, reducing the cost of emergency control strategies such as machine cutting and load cutting, and improving the stability of the power grid.

[0064] Second embodiment.

[0065] Based on the first embodiment, Figure 2 As shown, in the second embodiment of the present application, the method for controlling the temporary stability of the power grid by the photovoltaic charging station of the present application includes the following steps:

[0066] Step S210, determining a predicted fault set according to the power grid topology;

[0067] Step S220, calculating a distribution factor of each photovoltaic charging station within the power grid topology based on the expected faults in the expected fault set;

[0068] Step S230 : generating a photovoltaic charging station distribution factor table corresponding to the expected fault according to the distribution factors of each photovoltaic charging station.

[0069] In this embodiment, the grid topology can be changed according to actual needs. A corresponding expected fault set can be pre-set for each grid topology. The expected fault set includes various expected faults that may occur under the grid topology.

[0070] Optionally, the grid topology can be analyzed to identify anticipated faults. The distribution factors of each PV-storage charging station within the grid topology under the anticipated fault are determined. Based on the distribution factors of each PV-storage charging station, a PV-storage charging station distribution factor table corresponding to the anticipated fault is generated. The anticipated fault can be a three-phase permanent short circuit, a single-phase permanent short circuit, or a three-phase disconnection. Based on the current distribution network topology, the fault probability, and empirical experience, a fault set is established.

[0071] Optionally, the distribution factor of the photovoltaic charging station is used to characterize the location of the photovoltaic charging station in the power grid topology when a power grid fault occurs. Optionally, determining the photovoltaic charging station distribution factor table under the expected fault includes: obtaining the electrical distance between each photovoltaic charging station and each power source within the power grid topology under the expected fault; determining the power source electrically closest to each photovoltaic charging station based on the electrical distance; determining the participation factor of the power source electrically closest to each photovoltaic charging station; and determining the distribution factor of each photovoltaic charging station within the power grid topology under the expected fault based on the participation factor and the ratio of the electrical distance between the photovoltaic charging station and the power source electrically closest to the photovoltaic charging station.

[0072] Specifically, the distribution factor of each solar-storage charging station in the solar-storage charging station distribution factor table is the ratio of the participation factor of the power source closest to the solar-storage charging station under the fault to the electrical distance of the power source. The formula can be used: Calculate the distribution factor of each solar-storage charging station, where P j is the participation factor of the power source that is closest to the solar-storage charging station; d ij is the electrical distance between the solar-powered charging station and its nearest power source, j. Specifically, given the current grid topology, since the electrical distance between each power source and the solar-powered charging station is different, the electrical distance between each power source and the solar-powered charging station can be calculated. The participation factor of the power source with the closest electrical distance can then be selected, along with the electrical distance between the closest power source and the solar-powered charging station, to calculate the distribution factor for the solar-powered charging station. Since the grid topology contains multiple solar-powered charging stations, the distribution factor for each solar-powered charging station can be calculated using the above method; this can then generate a table of solar-powered charging station distribution factors associated with the fault.

[0073] Step S110: When a fault occurs in the power grid, a distribution factor of each photovoltaic charging station associated with the fault is determined.

[0074] Optionally, when a power grid fault occurs, the distribution factors of each solar-powered charging station associated with the fault can be determined based on the solar-powered charging station distribution factor table determined above. Specifically, a solar-powered charging station distribution factor table corresponding to the fault can be determined, and the distribution factors in the solar-powered charging station distribution factor table can be used as the distribution factors of each solar-powered charging station associated with the fault.

[0075] Step S120, comparing the distribution factor of each of the solar-energy storage charging stations with a preset value, and determining a control strategy corresponding to each of the solar-energy storage charging stations based on the comparison result;

[0076] Step S130: Control the operation of each of the solar-powered charging stations according to the corresponding control strategy.

[0077] According to the above technical solution, this embodiment can perform simulation calculations based on the fault set in the power grid to obtain the distribution factor of each photovoltaic charging station in the power grid corresponding to each expected fault; once a fault occurs in the power grid, the distribution factor of each photovoltaic charging station is obtained by looking up the table, and a differentiated control strategy is implemented according to the difference in distribution factors. During the control process, for photovoltaic charging stations with higher distribution factors, which are located in the leading group under the power grid fault, the charging power of the photovoltaic charging station should be increased, the energy storage module should be operated in charging mode, and the photovoltaic module should be operated in reactive power mode; for photovoltaic charging stations with lower distribution factors, which are located in the remaining group under the power grid fault, the charging power of the photovoltaic charging station should be reduced, the energy storage module should be operated in discharge mode, and the photovoltaic should be operated in MPPT mode. Because differentiated control strategies can be implemented based on the difference in distribution factors of photovoltaic charging stations. Because this application adopts the above-mentioned temporary stabilization control method, the power grid can also provide stable power when the photovoltaic charging station cuts off the generator or cuts off the load.

[0078] An embodiment of the present invention provides an embodiment of a method for temporarily stabilizing a power grid in which a photovoltaic charging station participates. It should be noted that although a logical sequence is shown in the flow chart, in some cases, the steps shown or described may be performed in an order different from that shown here.

[0079] like Figure 3 As shown, Figure 3 This is a structural diagram of the hardware operating environment of the temporary stability control device of the photovoltaic storage charging station participating in the power grid involved in the embodiment of the present invention.

[0080] like Figure 3 As shown, the temporary stability control device of the photovoltaic charging station participating in the power grid may include: a processor 1001, such as a CPU, a memory 1005, a user interface 1003, a network interface 1004, and a communication bus 1002. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the user interface 1003 may also include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a WI-FI interface). The memory 1005 may be a high-speed RAM memory, or a stable memory (non-volatile memory), such as a disk memory. The memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0081] Those skilled in the art will understand that Figure 3The structure of the temporary stabilization control device for the photovoltaic storage charging station participating in the power grid shown in the figure does not constitute a limitation on the temporary stabilization control device for the photovoltaic storage charging station participating in the power grid, and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0082] like Figure 3 As shown, memory 1005, a storage medium, may include an operating system, a network communication module, a user interface module, and a temporary stabilization control program for the PV-storage charging station participating in the power grid. The operating system is a program that manages and controls the hardware and software resources of the temporary stabilization control device for the PV-storage charging station participating in the power grid, and the operation of the temporary stabilization control program for the PV-storage charging station participating in the power grid, as well as other software or programs.

[0083] exist Figure 3 In the temporary stability control device for the photovoltaic charging station participating in the power grid shown, the user interface 1003 is mainly used to connect to the terminal and communicate data with the terminal; the network interface 1004 is mainly used for the background server and communicates data with the background server; the processor 1001 can be used to call the temporary stability control program for the photovoltaic charging station participating in the power grid stored in the memory 1005.

[0084] In this embodiment, the device for controlling the temporary stability of a photovoltaic charging station participating in a power grid includes: a memory 1005, a processor 1001, and a program for controlling the temporary stability of a photovoltaic charging station participating in a power grid stored in the memory and executable on the processor, wherein:

[0085] When the processor 1001 calls the temporary stability control program for the photovoltaic charging station to participate in the power grid stored in the memory 1005, the following operations are performed:

[0086] When a power grid fault occurs, determining a distribution factor for each solar-powered charging station associated with the fault, wherein each distribution factor is a ratio of a participation factor of a power source electrically closest to the corresponding solar-powered charging station under the fault to the electrical distance between the power source and the corresponding solar-powered charging station;

[0087] Comparing the distribution factor of each of the solar-energy storage charging stations with a preset value, and determining a control strategy for each of the solar-energy storage charging stations based on the comparison result;

[0088] According to the control strategy, each of the solar-powered charging stations is controlled to operate.

[0089] When the processor 1001 calls the temporary stability control program for the photovoltaic charging station to participate in the power grid stored in the memory 1005, the following operations are performed:

[0090] Comparing the distribution factor of each of the solar-storage charging stations with the first preset value or the second preset value to obtain a comparison result;

[0091] Determine the group to which each of the solar-storage charging stations belongs based on the comparison results;

[0092] Determine the control strategy of each of the photovoltaic charging stations in the group.

[0093] When the processor 1001 calls the temporary stability control program for the photovoltaic charging station to participate in the power grid stored in the memory 1005, the following operations are performed:

[0094] If the distribution factor of the solar-energy storage charging station is greater than the first preset value, it is determined that the corresponding solar-energy storage charging station is located in the leading group; or

[0095] If the distribution factor of the solar-powered charging station is less than the second preset value, it is determined that the corresponding solar-powered charging station is located in the remaining group, and the second preset value is less than the first preset value.

[0096] When the processor 1001 calls the temporary stability control program for the photovoltaic charging station to participate in the power grid stored in the memory 1005, the following operations are performed:

[0097] When the group is the leading group, determining the first control strategy as the control strategy of each photovoltaic charging station in the leading group; or,

[0098] When the group is the remaining group, the second control strategy is determined to be the control strategy of each photovoltaic charging station in the remaining group.

[0099] When the processor 1001 calls the temporary stability control program for the photovoltaic charging station to participate in the power grid stored in the memory 1005, the following operations are performed:

[0100] The first control strategy includes: increasing the charging power of each photovoltaic charging station in the leading group, that is, controlling the energy storage module to operate in a charging mode and controlling the photovoltaic module to operate in a reactive power mode;

[0101] Alternatively, the second control strategy includes: reducing the charging power of each photovoltaic charging station in the remaining group, that is, controlling the energy storage module to operate in a discharge mode and controlling the photovoltaic module to operate in a maximum power point tracking mode.

[0102] When the processor 1001 calls the temporary stability control program for the photovoltaic charging station to participate in the power grid stored in the memory 1005, the following operations are performed:

[0103] Determine the expected fault set based on the power grid topology;

[0104] Calculating a distribution factor of each photovoltaic charging station within the power grid topology based on the anticipated faults in the anticipated fault set;

[0105] A distribution factor table of the photovoltaic charging stations corresponding to the expected fault is generated according to the distribution factors of the photovoltaic charging stations.

[0106] When the processor 1001 calls the temporary stability control program for the photovoltaic charging station to participate in the power grid stored in the memory 1005, the following operations are performed:

[0107] Obtaining the electrical distance between each of the photovoltaic charging stations and each power source in the grid topology under the expected fault;

[0108] Determine the power source closest to the corresponding solar-storage charging station based on the electrical distance;

[0109] determining a participation factor of the power source that is electrically closest;

[0110] The distribution factor of each of the photovoltaic charging stations within the grid topology under the expected fault is determined according to the participation factor and the ratio of the electrical distance between the photovoltaic charging station and the power source closest to the photovoltaic charging station.

[0111] When the processor 1001 calls the temporary stability control program for the photovoltaic charging station to participate in the power grid stored in the memory 1005, the following operations are performed:

[0112] When a fault occurs in the power grid, a distribution factor table of photovoltaic charging stations corresponding to the fault is determined;

[0113] The distribution factors in the photovoltaic charging station distribution factor table are determined as the distribution factors of each photovoltaic charging station associated with the fault.

[0114] Based on the same inventive concept, this application also provides a photovoltaic charging system comprising at least two photovoltaic charging stations, each of which has a corresponding photovoltaic module and energy storage module. The photovoltaic charging station can be charged via the power grid, or the photovoltaic module and energy storage module can be used to charge the photovoltaic charging station. A temporary stabilization control device for the photovoltaic charging station to participate in the power grid is also provided between the power grid and the photovoltaic charging station.

[0115] Among them, the temporary stability control device of the photovoltaic charging station participating in the power grid can be used to monitor whether a fault occurs in the distribution network and the specific fault, and determine the distribution factor of each photovoltaic charging station associated with the fault; compare the distribution factor of each photovoltaic charging station with a preset value to determine the group to which each photovoltaic charging station belongs, and then control the operation of each photovoltaic charging station according to the control strategy corresponding to the group.

[0116] The specific implementation of the photovoltaic storage charging system of the present invention is basically the same as the embodiments of the above-mentioned photovoltaic storage charging station participating in the temporary stability control method of the power grid, and will not be repeated here.

[0117] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0118] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0119] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0120] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0121] It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claim. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, third etc. does not indicate any order. These words may be interpreted as names.

[0122] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0123] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for controlling temporary stability of a power grid with a photovoltaic charging station, characterized in that: The method comprises: When a power grid fault occurs, determining a distribution factor for each solar-powered charging station associated with the fault, wherein each distribution factor is a ratio of a participation factor of a power source electrically closest to the corresponding solar-powered charging station under the fault to the electrical distance between the power source and the corresponding solar-powered charging station; Comparing the distribution factor of each of the solar-storage charging stations with a preset value, and determining a control strategy for each of the solar-storage charging stations based on the comparison results, wherein for solar-storage charging stations with higher distribution factors, the charging power of the solar-storage charging stations is increased; and for solar-storage charging stations with lower distribution factors, the charging power of the solar-storage charging stations is reduced; According to the control strategy, each of the solar-powered charging stations is controlled to operate.

2. The method according to claim 1, wherein The step of comparing the distribution factor of each of the solar-energy storage charging stations with a preset value and determining the control strategy of each of the solar-energy storage charging stations according to the comparison result includes: Comparing the distribution factor of each of the solar-storage charging stations with the first preset value or the second preset value to obtain a comparison result; Determine the group to which each of the solar-storage charging stations belongs based on the comparison results; Determine the control strategy of each of the photovoltaic charging stations in the group.

3. The method according to claim 2, wherein The group includes a leading group or a remaining group; and the step of determining the group to which each of the solar-powered charging stations belongs based on the comparison result includes: If the distribution factor of the solar-energy storage charging station is greater than the first preset value, it is determined that the corresponding solar-energy storage charging station is located in the leading group; or If the distribution factor of the solar-powered charging station is less than the second preset value, it is determined that the corresponding solar-powered charging station is located in the remaining group, and the second preset value is less than the first preset value.

4. The method according to claim 3, wherein The step of determining the control strategy of each of the solar-storage charging stations in the group includes: When the group is the leading group, determining the first control strategy as the control strategy of each photovoltaic charging station in the leading group; or, When the group is the remaining group, the second control strategy is determined to be the control strategy of each photovoltaic charging station in the remaining group.

5. The method according to claim 4, wherein The first control strategy includes: increasing the charging power of each photovoltaic charging station in the leading group, that is, controlling the energy storage module to operate in a charging mode and controlling the photovoltaic module to operate in a reactive power mode; Alternatively, the second control strategy includes: reducing the charging power of each photovoltaic charging station in the remaining group, that is, controlling the energy storage module to operate in a discharge mode and controlling the photovoltaic module to operate in a maximum power point tracking mode.

6. The method according to claim 1, wherein Before the step of determining the distribution factors of each photovoltaic charging station associated with the fault when a fault occurs in the power grid, the method includes: Determine the expected fault set based on the power grid topology; Calculating a distribution factor of each photovoltaic charging station within the power grid topology based on the anticipated faults in the anticipated fault set; A distribution factor table of the photovoltaic charging stations corresponding to the expected fault is generated according to the distribution factors of the photovoltaic charging stations.

7. The method according to claim 6, wherein The step of calculating the distribution factor of each photovoltaic charging station within the power grid topology structure based on the anticipated fault in the anticipated fault set includes: Obtaining the electrical distance between each of the photovoltaic charging stations and each power source in the grid topology under the expected fault; Determine the power source closest to the corresponding solar-storage charging station based on the electrical distance; determining a participation factor of the power source that is electrically closest; The distribution factor of each of the photovoltaic charging stations within the grid topology under the expected fault is determined according to the participation factor and the ratio of the electrical distance between the photovoltaic charging station and the power source closest to the photovoltaic charging station.

8. The method according to claim 6, wherein When a power grid fault occurs, the step of determining the distribution factor of each photovoltaic charging station associated with the fault includes: When a fault occurs in the power grid, a distribution factor table of photovoltaic charging stations corresponding to the fault is determined; The distribution factors in the photovoltaic charging station distribution factor table are determined as the distribution factors of each photovoltaic charging station associated with the fault.

9. A temporary stability control device for a photovoltaic charging station participating in a power grid, characterized in that: The temporary stability control device for the photovoltaic storage charging station participating in the power grid includes: a memory, a processor, and a temporary stability control program for the photovoltaic storage charging station participating in the power grid stored in the memory and executable on the processor. When the temporary stability control program for the photovoltaic storage charging station participating in the power grid is executed by the processor, the steps of the temporary stability control method for the photovoltaic storage charging station participating in the power grid as described in any one of claims 1-8 are implemented.

10. A solar storage charging system, characterized in that: The solar energy storage charging system includes: At least two solar-storage charging stations; And, the photovoltaic storage charging station participating in the temporary stability control device of the power grid as described in claim 9.

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