A method for controlling energy storage in low-voltage distribution area

Abstract

The present invention discloses an energy storage control method for a low-voltage distribution station area. The method comprises the following steps: firstly obtaining the predicted power consumption of the station area in the next time period and the charge state of all energy storage devices in the station area; determining a set of grid-connected energy storage devices to be used based on the charge state of all energy storage devices; determining a grid-connected power supply energy storage device in the set of energy storage devices to be connected to the grid according to the predicted power consumption of the station area and the overload power supply of the low-voltage transformer; and when the next time period arrives, connecting all the grid-connected power supply energy storage devices to the grid for power supply, thereby improving the power supply quality of the low-voltage distribution station area and enhancing the user experience of power users.

Description

Technical Field

[0001] The present invention relates to the technical field of low-voltage power distribution, and in particular to an energy storage control method for a low-voltage power distribution station area. Background Art

[0002] In the power system, the low-voltage distribution system is directly connected to various loads of power users. The power supply reliability and power quality of the low-voltage distribution system directly affect the normal power consumption of users. Among them, in the low-voltage distribution system, the substation refers to the power supply area of a single transformer, and the low-voltage distribution substation is also the power supply area of the low-voltage transformer.

[0003] Currently, low-voltage distribution substations are plagued by problems such as peak-to-valley differences in electricity consumption, three-phase imbalance, and voltage drops. Furthermore, electricity users' demand for electricity varies significantly at different times, seasons, and regions, leading to an increasingly prominent demand for peak load regulation. However, the existing distribution network is not suitable for comprehensive upgrades and renovations. While mobile energy storage technology is becoming increasingly mature, energy storage equipment in low-voltage distribution substations can be used to improve power supply reliability and quality. However, existing controls for controlling energy storage in low-voltage distribution substations are not perfect and cannot effectively improve power supply reliability and quality.

[0004] Therefore, how to improve the power supply quality of low-voltage distribution stations, thereby improving the user experience of power users, is a technical problem to be solved by those skilled in the art. Summary of the Invention

[0005] The technical purpose of the present invention is to improve the power supply quality of low-voltage distribution stations. To achieve the above technical purpose, in a first aspect, an embodiment of the present invention provides an energy storage control method for a low-voltage distribution station, the method comprising:

[0006] Obtain the predicted power consumption of the substation in the next time period and the charge status of all energy storage devices in the substation;

[0007] Determining a set of grid-connected energy storage devices to be used based on the charge states of all energy storage devices;

[0008] Determine the grid-connected power supply storage device from the energy storage devices to be connected to the grid based on the predicted power consumption of the substation area and the overload power supply of the low-voltage transformer;

[0009] When the next time period arrives, all grid-connected power supply and energy storage devices are connected to the grid for power supply.

[0010] Furthermore, it also includes a first neural network, which is used to obtain the predicted electricity consumption of the substation in the next time period.

[0011] Furthermore, the state of charge of all energy storage devices is obtained, including:

[0012] Build a composite model for each energy storage device;

[0013] The state of charge of the corresponding energy storage device is determined based on the composite model.

[0014] Furthermore, the composite model is specifically as follows:

[0015]

[0016] Where k0, k1, k2, k3 and k4 are model matching coefficients, V k is the voltage of the energy storage device, R is the ohmic resistance of the energy storage device, SOC k is the state of charge of the energy storage device, i k is the discharge current.

[0017] Furthermore, the step of centrally determining the grid-connected energy storage device from the energy storage devices to be connected to the grid based on the predicted power consumption of the substation area and the overload power supply of the low-voltage transformer specifically includes:

[0018] Dividing the subarea into a plurality of subareas based on power user points;

[0019] Predicting the predicted electricity consumption of all sub-regions by using the first neural network, and arranging all sub-regions in descending order based on the predicted electricity consumption of all sub-regions to obtain an arrangement table;

[0020] Determining the power supply amount to be compensated based on the predicted power consumption of the substation area and the overload power supply amount;

[0021] Determine the grid connection locations of all energy storage devices to be connected to the grid in the energy storage device cluster;

[0022] The grid-connected power supply storage device is determined based on the arrangement table, the grid-connected location and the power supply amount to be compensated.

[0023] Furthermore, determining the grid-connected power supply storage device based on the arrangement table, the grid-connected location, and the power supply amount to be compensated specifically includes:

[0024] Determining a sub-area to be compensated in the arrangement table according to the power supply to be compensated;

[0025] The grid-connected energy storage device to be connected to the grid, whose grid-connected position is located at the power supply entrance of the sub-area to be compensated, is used as the grid-connected power supply energy storage device.

[0026] Furthermore, determining the sub-area to be compensated in the arrangement table according to the power supply to be compensated specifically includes:

[0027] If the power supply to be compensated is greater than the power supply of all grid-connected energy storage devices at the power supply entrance of the first sub-area in the arrangement list, both the first sub-area and the second sub-area in the arrangement list are set as sub-areas to be compensated;

[0028] If the power supply to be compensated is less than the power supply of all grid-connected energy storage devices at the power supply entrance of the first sub-area in the arrangement list, the first sub-area in the arrangement list is set as the sub-area to be compensated.

[0029] Furthermore, the method further comprises:

[0030] If the predicted electricity consumption of the substation in the next time period is less than the preset electricity consumption, the energy storage equipment in the substation will be charged.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] An embodiment of the present invention provides an energy storage control method for a low-voltage distribution station area. The method first obtains the predicted power consumption of the station area in the next time period and the charge status of all energy storage devices in the station area; determines a set of grid-connected energy storage devices to be used based on the charge status of all energy storage devices; determines the grid-connected power supply energy storage devices in the set of energy storage devices to be connected to the grid according to the predicted power consumption of the station area and the overload power supply of the low-voltage transformer; when the next time period arrives, connects all the grid-connected power supply energy storage devices to the grid for power supply, thereby improving the power supply quality of the low-voltage distribution station area and enhancing the user experience of power users. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0034] Figure 1 A flow chart of an energy storage control method for a low-voltage distribution station area provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the embodiments described are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without making any creative efforts should fall within the scope of protection of this specification.

[0036] It should be understood that although the terms first, second, third, etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0037] In order to better control the energy storage equipment in the low-voltage distribution station area, the present application provides an energy storage control method for the low-voltage distribution station area, such as Figure 1 As shown, the method includes:

[0038] Step S101: Obtain the predicted power consumption of the substation in the next time period and the charge status of all energy storage devices in the substation.

[0039] In an embodiment of the present application, a first neural network is also included, and the first neural network is used to obtain the predicted electricity consumption of the substation in the next time period.

[0040] Specifically, the first neural network is a mathematical model, and the historical electricity consumption of the substation is input into the first neural network in advance for training, so that the neural network can predict the electricity consumption of the substation in the next time period.

[0041] The energy storage device is specifically a rechargeable battery. The selection of the energy storage device is flexibly made by technical personnel in this field based on actual conditions. The state of charge is one of the important parameters of the battery management system. Its value describes the current remaining power of the battery. Accurate estimation of the battery state of charge can prevent the battery from overcharging or over-discharging, thereby extending the remaining battery service life. The battery state of charge is the percentage of the battery's remaining capacity to the battery's rated capacity.

[0042] In this application, the state of charge of all energy storage devices is obtained, including:

[0043] Build a composite model for each energy storage device;

[0044] The state of charge of the corresponding energy storage device is determined based on the composite model.

[0045] The composite model is specifically as follows:

[0046]

[0047] Where k0, k1, k2, k3 and k4 are model matching coefficients, V k is the voltage of the energy storage device, R is the ohmic resistance of the energy storage device, SOC k is the state of charge of the energy storage device, i k is the discharge current.

[0048] Specifically, the model matching coefficient can be obtained from a complete discharge test of the battery, and the performance of the composite model is far better than other empirical models.

[0049] Step S102: Determine a set of grid-connected energy storage devices to be used based on the charge states of all energy storage devices.

[0050] Specifically, all energy storage devices whose state of charge is greater than a first threshold and whose state of charge after discharge for a preset time period is greater than a second threshold are combined into a set of energy storage devices to be connected to the grid. By setting the first threshold and the second threshold, it is ensured that the energy storage devices will not be over-discharged, thereby causing damage to the energy storage devices.

[0051] Step S103: determining a grid-connected power supply storage device from among the energy storage devices to be grid-connected according to the predicted power consumption of the substation and the overload power supply of the low-voltage transformer.

[0052] In the embodiment of the present application, determining the grid-connected power supply storage device in the energy storage device to be grid-connected based on the predicted power consumption of the substation area and the overload power supply of the low-voltage transformer specifically includes:

[0053] Dividing the subarea into a plurality of subareas based on power user points;

[0054] Predicting the predicted electricity consumption of all sub-regions by using the first neural network, and arranging all sub-regions in descending order based on the predicted electricity consumption of all sub-regions to obtain an arrangement table;

[0055] Determining the power supply amount to be compensated based on the predicted power consumption of the substation area and the overload power supply amount;

[0056] Determine the grid connection locations of all energy storage devices to be connected to the grid in the energy storage device cluster;

[0057] The grid-connected power supply storage device is determined based on the arrangement table, the grid-connected location and the power supply amount to be compensated.

[0058] Specifically, electricity users are unevenly distributed within a substation area. Some areas have concentrated or high-power users with high electricity demand, while other areas have fewer and more dispersed users with low electricity demand. When electricity users are relatively concentrated or there are high-power users, such as factories, laboratories, or residential areas, these users are treated as separate sub-areas. When electricity users are dispersed and there are no high-power users, all users within a preset area are treated as a sub-area. Energy storage equipment is installed at the nearest power supply entrance in each sub-area.

[0059] The predicted electricity consumption of all sub-regions is predicted by the first neural network. When training the first neural network, the historical electricity consumption of the substation is divided into different data according to the sub-regions, and the first neural network is trained separately. After obtaining the predicted electricity consumption of the sub-regions, all sub-regions are arranged in descending order according to the predicted electricity consumption to obtain an arrangement table, and then the grid-connected positions of all the energy storage devices to be grid-connected in the set of energy storage devices to be grid-connected are obtained.

[0060] In an embodiment of the present application, determining the grid-connected power supply storage device based on the arrangement table, the grid-connected location, and the power supply amount to be compensated specifically includes:

[0061] Determining a sub-area to be compensated in the arrangement table according to the power supply to be compensated;

[0062] The grid-connected energy storage device to be connected to the grid, whose grid-connected position is located at the power supply entrance of the sub-area to be compensated, is used as the grid-connected power supply energy storage device.

[0063] In the embodiment of the present application, determining the sub-area to be compensated in the arrangement table according to the power supply to be compensated specifically includes:

[0064] If the power supply to be compensated is greater than the power supply of all grid-connected energy storage devices at the power supply entrance of the first sub-area in the arrangement list, both the first sub-area and the second sub-area in the arrangement list are set as sub-areas to be compensated;

[0065] If the power supply to be compensated is less than the power supply of all grid-connected energy storage devices at the power supply entrance of the first sub-area in the arrangement list, the first sub-area in the arrangement list is set as the sub-area to be compensated.

[0066] Specifically, the energy storage equipment of the present application can be regarded as providing power supply compensation for different sub-areas respectively, and there is also energy storage equipment set up at the common power supply point of multiple sub-areas. It should be noted that the low-voltage distribution station area may be urban or rural. When setting up the energy storage equipment, it is necessary to determine the energy storage equipment based on the historical power consumption of the station area, specifically, the difference between the peak power consumption in the previous year and the overload power supply of the low-voltage transformer is less than the power supply of all energy storage devices. When determining the sub-area to be compensated, the top-ranked sub-area is prioritized as the sub-area to be compensated. In addition, after determining the sub-area to be compensated, it is also necessary to determine whether the energy storage device at the power supply entrance closest to the sub-area to be compensated is within the set of energy storage devices to be connected to the grid. If not, determine within the set of energy storage devices to be connected to the grid whether the energy storage device at the power supply entrance of the previous level of the nearest power supply entrance is within the set of energy storage devices to be connected to the grid. If the energy storage device at the previous level of power supply entrance is still not within the set of energy storage devices to be connected to the grid, re-determine the sub-area to be compensated based on the arrangement table, that is, use the sub-area next to the original sub-area to be compensated as the sub-area to be compensated, or sort the arrangement table in reverse order and use the sub-areas to be compensated in sequence according to the reverse order.

[0067] Step S104: When the next time period arrives, all grid-connected power supply and energy storage devices are connected to the grid for power supply.

[0068] Specifically, when all grid-connected energy storage devices are supplying power, the operating status of the grid-connected energy storage devices will be monitored in real time, including judging the health status of the grid-connected energy storage devices based on their discharge curves, and timely connecting the remaining energy storage devices as grid-connected energy storage devices for grid supply power based on their health status.

[0069] In an embodiment of the present application, the method further includes:

[0070] If the predicted electricity consumption of the substation in the next time period is less than the preset electricity consumption, the energy storage equipment in the substation will be charged.

[0071] Specifically, the electricity consumption in the substation fluctuates throughout the day or seasonal cycles. When the electricity consumption in the substation is low, the energy storage device is charged through a low-voltage transformer to ensure that the energy storage device can operate normally during the peak electricity consumption period in the substation.

[0072] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-mentioned embodiments, ordinary technicians in this field should understand that any technician familiar with this technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed by the present invention, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention.

Claims

1. A method for controlling energy storage in a low-voltage distribution station area, characterized in that: The method comprises: Obtain the predicted power consumption of the substation in the next time period and the charge status of all energy storage devices in the substation; Determining a set of grid-connected energy storage devices to be used based on the charge states of all energy storage devices; Determine the grid-connected power supply storage device from the energy storage devices to be connected to the grid based on the predicted power consumption of the substation area and the overload power supply of the low-voltage transformer; When the next time period arrives, all grid-connected power supply and energy storage devices are connected to the grid for power supply; It also includes a first neural network, which is used to obtain the predicted amount of electricity consumption in the substation area in the next time period; Obtain the state of charge of all energy storage devices, including: Build a composite model for each energy storage device; Determining a state of charge of a corresponding energy storage device based on the composite model; The composite model is specifically as follows: Where k0, k1, k2, k3 and k4 are model matching coefficients, V k is the voltage of the energy storage device, R is the ohmic resistance of the energy storage device, SOC k is the state of charge of the energy storage device, i k is the discharge current; The step of centrally determining the grid-connected power supply storage device from the energy storage devices to be connected to the grid based on the predicted power consumption of the substation area and the overload power supply of the low-voltage transformer specifically includes: Dividing the subarea into a plurality of subareas based on power user points; Predicting the predicted electricity consumption of all sub-regions by using the first neural network, and arranging all sub-regions in descending order based on the predicted electricity consumption of all sub-regions to obtain an arrangement table; Determining the power supply amount to be compensated based on the predicted power consumption of the substation area and the overload power supply amount; Determine the grid connection locations of all energy storage devices to be connected to the grid in the energy storage device cluster; Determine a grid-connected power supply energy storage device based on the arrangement table, the grid-connected location and the power supply amount to be compensated; The determining of the grid-connected power supply storage device based on the arrangement table, the grid-connected location, and the power supply amount to be compensated specifically includes: Determining a sub-area to be compensated in the arrangement table according to the power supply to be compensated; The grid-connected energy storage device to be connected, whose grid-connected position is located at the power supply entrance of the sub-area to be compensated, is used as the grid-connected power supply energy storage device; The step of determining the sub-area to be compensated in the arrangement table according to the power supply to be compensated specifically includes: If the power supply to be compensated is greater than the power supply of all grid-connected energy storage devices at the power supply entrance of the first sub-area in the arrangement list, both the first sub-area and the second sub-area in the arrangement list are set as sub-areas to be compensated; If the power supply to be compensated is less than the power supply of all grid-connected energy storage devices at the power supply entrance of the first sub-area in the arrangement list, the first sub-area in the arrangement list is set as the sub-area to be compensated.

2. The energy storage control method for a low-voltage distribution station area according to claim 1, characterized in that: The method further comprises: If the predicted electricity consumption of the substation in the next time period is less than the preset electricity consumption, the energy storage equipment in the substation will be charged.

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