Distribution network area voltage management method and system with the participation of distributed energy storage in the area

Abstract

The present invention relates to a method and system for voltage management in a distribution network substation with the participation of distributed energy storage in the substation, wherein the method comprises: obtaining three-phase voltage data of a distributed energy storage grid-connected point in the distribution network substation; when one phase voltage data or multiple phase voltage data in the three-phase voltage data has a voltage over-limit situation, voltage management is performed on the phase voltage of the distributed energy storage grid-connected point where the voltage over-limit situation exists; in the process of voltage management of the phase voltage of the distributed energy storage grid-connected point where the voltage over-limit situation exists, if the state of charge of the distributed energy storage satisfies the maintenance condition formed by dynamically maintaining the state of charge value, the power of each phase is adjusted according to the three-phase voltage data to realize the state of charge maintenance of the distributed energy storage. The present invention can efficiently, economically and comprehensively manage the voltage over-limit problem in the distribution network substation and improve the voltage quality in the substation.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage management in distribution network substations, and in particular to a method and system for voltage management in distribution network substations involving distributed energy storage in the substations. Background Art

[0002] With the rapid promotion of photovoltaic power generation in counties across the country and the large-scale growth of electric vehicles, as well as the fact that some distribution network substations have low-voltage lines with over-radius power supply, small conductor cross-section, large load at the end, and unreasonable distribution transformer gear settings, the voltage fluctuation and over-limit phenomenon are serious, which seriously affects the power supply reliability of the power grid and the voltage quality of the substation. In order to solve the problem of over-limit voltage in the distribution network substation, measures such as transformation of distribution network lines, distribution capacity expansion, distribution transformer gear adjustment, and restriction of distributed photovoltaic access and its active output can be adopted. However, the approval and construction time for the transformation of distribution network lines and distribution capacity expansion is long, the transformation cost is high, and the utilization rate of seasonal and time-limited load equipment is low. The distribution transformer gear adjustment cannot cope with the dynamic changes in voltage, and restricting the access of distributed photovoltaics and its active output will cause a certain loss of power generation.

[0003] The existing public patent document CN112152259A discloses a distributed photovoltaic grid-connected collaborative control method and system for preventing voltage over-limit. It solves the voltage over-limit phenomenon by adding back-to-back converters to control the reactive power of the distributed photovoltaic power generation system grid-connected point. Since it adds hardware devices, the cost is relatively high, and the output active power of the distributed photovoltaic power generation system is limited by controlling the working state of the photovoltaic inverter, resulting in a certain loss of power generation.

[0004] The existing public patent document CN114123218A discloses a method for suppressing overvoltage in a distributed photovoltaic terminal distribution network by hierarchical zoning. The method mainly makes full use of the reactive regulation capacity of the photovoltaic grid-connected inverter, reduces the cost of reactive compensation equipment, and calls on the reactive power capacity of the inverter of the entire network through the reactive optimization coordination control strategy of a single / multiple inverters, and finally collaboratively eliminates the overvoltage situation at the grid connection point. However, the method does not distinguish the degree of voltage exceeding the limit, which will cause excessive regulation and affect the power generation of distributed photovoltaics. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method and system for voltage management in a distribution network substation with the participation of distributed energy storage in the substation, which can efficiently, economically and comprehensively manage the voltage over-limit problem in the distribution network substation and improve the voltage quality in the substation.

[0006] The technical solution adopted by the present invention to solve the technical problem is: to provide a method for voltage management in a distribution network area with the participation of distributed energy storage in the area, comprising the following steps:

[0007] Obtain three-phase voltage data of distributed energy storage grid connection points in distribution network areas;

[0008] When one phase voltage data or multiple phase voltage data in the three-phase voltage data exceeds the voltage limit, voltage management is performed on the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the voltage limit;

[0009] In the process of voltage management of the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit, if the state of charge (SOC) of the distributed energy storage meets the maintenance conditions formed by the dynamic maintenance state of charge value, the power of each phase is adjusted according to the three-phase voltage data to achieve the state of charge maintenance of the distributed energy storage.

[0010] The voltage management of the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit specifically includes:

[0011] Determine whether the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the upper limit control target value, and whether the distributed energy storage is not in a charging prohibition state;

[0012] If the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the upper limit control target value, and the distributed energy storage is not in a charging prohibition state, the corresponding phase power of the distributed energy storage will be reduced by a voltage over-limit control power adjustment step.

[0013] If the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit does not exceed the upper limit governance target value, or the distributed energy storage is in a charging prohibited state, then determine whether the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit exceeds the lower limit governance target value and is less than the difference between the upper limit governance target value and the dead zone value, and whether the corresponding phase power of the distributed energy storage is less than zero;

[0014] If the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the lower limit control target value and is less than the difference between the upper limit control target value and the dead zone value, and the corresponding phase power of the distributed energy storage is less than zero, it is determined whether the distributed energy storage is in the state of charge maintenance state;

[0015] If the distributed energy storage is not in the state of charge maintenance state, the corresponding phase power of the distributed energy storage is increased by a voltage over-limit management power adjustment step.

[0016] If the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit does not exceed the lower limit management target value, or is not less than the difference between the upper limit management target value and the dead zone value, or the phase power of the corresponding distributed energy storage is greater than zero, or the distributed energy storage is in the state of charge maintenance, then it is determined whether the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit is less than the lower limit management target value, and whether the distributed energy storage is not in a prohibited state;

[0017] If the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit is less than the lower limit management target value, and the distributed energy storage is not in a prohibited state, the corresponding phase power of the distributed energy storage will be increased by a voltage exceeding the limit management power adjustment step.

[0018] If the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit is not less than the lower limit management target value, or the distributed energy storage is in a prohibited state, then determine whether the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit is less than the upper limit management target value and greater than the sum of the upper limit management target value and the dead zone value, and whether the corresponding phase power of the distributed energy storage is greater than zero;

[0019] If the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit is less than the upper limit management target value and greater than the sum of the upper limit management target value and the dead zone value, and the corresponding phase power of the distributed energy storage is greater than zero, it is determined whether the distributed energy storage is in the state of charge maintenance state;

[0020] If the distributed energy storage is not in the state of charge maintenance state, the corresponding phase power of the distributed energy storage is subtracted from a voltage over-limit management power adjustment step.

[0021] If the state of charge of the distributed energy storage meets the maintenance condition formed by dynamically maintaining the state of charge value, the power of each phase is adjusted according to the three-phase voltage data to achieve the state of charge maintenance of the distributed energy storage, specifically including:

[0022] Determine whether the state of charge of the distributed energy storage is greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in the state of charge discharge maintenance state;

[0023] If the state of charge of the distributed energy storage is greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and the distributed energy storage is not in the state of charge discharge maintenance state, the distributed energy storage is made to enter the state of charge discharge maintenance state;

[0024] If the state of charge of the distributed energy storage is not greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, or the distributed energy storage is in the state of charge discharge maintenance state, then determine whether the state of charge of the distributed energy storage is less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in the state of charge charging maintenance state;

[0025] If the state of charge of the distributed energy storage is less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and the distributed energy storage is not in the state of charge charging maintenance state, the distributed energy storage is made to enter the state of charge charging maintenance state;

[0026] If the state of charge of the distributed energy storage is not less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, or the distributed energy storage is in the state of charge charging maintenance state, then it is determined whether the distributed energy storage is in the state of charge charging maintenance state or the state of charge discharging maintenance state;

[0027] If the distributed energy storage is in the state-of-charge charging maintenance state or the state-of-charge discharging maintenance state, the power of each phase is adjusted according to the three-phase voltage data;

[0028] If the distributed energy storage is not in the state of charge charging maintenance state and is not in the state of charge discharging maintenance state, determining whether the state of charge of the distributed energy storage is equal to the dynamic maintenance state of charge value;

[0029] If the state of charge of the distributed energy storage is equal to the dynamic maintenance state of charge value, the distributed energy storage is exited from the state of charge discharge maintenance state and the state of charge charging maintenance state.

[0030] The step of adjusting the power of each phase according to the three-phase voltage data specifically includes:

[0031] Determine whether the phase voltage of the distributed energy storage grid connection point is less than the difference between the upper limit management target value and the dead zone value and greater than the lower limit management target value, and whether the distributed energy storage is in the charged state discharge maintenance state;

[0032] If the phase voltage of the distributed energy storage grid connection point is less than the difference between the upper limit management target value and the dead zone value and greater than the lower limit management target value, and the distributed energy storage is in the state of charge discharge maintenance state, then the corresponding phase power of the distributed energy storage is increased by a voltage over-limit management power adjustment step;

[0033] Determine whether the phase voltage of the distributed energy storage grid connection point is greater than the sum of the lower limit management target value and the dead zone value and less than the upper limit management target value, and whether the distributed energy storage is in the state of charge charging maintenance state;

[0034] If the phase voltage of the distributed energy storage grid-connected point is greater than the sum of the lower limit management target value and the dead zone value and is less than the upper limit management target value, and the distributed energy storage is in the charged state and charging maintenance state, then the corresponding phase power of the distributed energy storage will be subtracted from a voltage over-limit management power adjustment step.

[0035] The dynamic maintenance state of charge value is determined by:

[0036] Extract the operating charge and discharge data of the distributed energy storage in the past K days, and segment the operating charge and discharge data in the past K days according to date and time to obtain the charge and discharge amount in each time period of each day in the past K days; where K is an integer greater than 1;

[0037] Compare the charging and discharging amounts of distributed energy storage in the same period of time in the past K days, take the maximum charging amount in each period as the charging demand of each period, and take the maximum discharging amount in each period as the discharging demand of each period;

[0038] Divide the charging demand and discharging demand of each period by the rated installed capacity of the distributed energy storage to obtain the change in the state of charge of each period;

[0039] Setting different charge states at the initial moment of operation of the distributed energy storage, and generating a series of distributed energy storage operation scenarios based on the different charge states at the initial moment of operation of the distributed energy storage;

[0040] According to different distributed energy storage operation scenarios, combined with the charge state changes in each period, the charge state of distributed energy storage at each time point in each operation scenario is calculated;

[0041] Filter out the operating scenarios where the state of charge at each time point is between the prohibited charging state of charge value and the prohibited discharging state of charge value;

[0042] From the screened operating scenarios, find the operating scenario corresponding to the median state of charge at the initial moment, and use the state of charge at each time point under the operating scenario as the maintenance state of charge value at each time point.

[0043] The technical solution adopted by the present invention to solve the technical problem is: to provide a distribution network area voltage management system in which distributed energy storage in the area participates, including:

[0044] An acquisition module is used to obtain three-phase voltage data of distributed energy storage grid connection points in the distribution network area;

[0045] A voltage management module is used to manage the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit when one phase voltage data or multiple phase voltage data in the three-phase voltage data exceeds the limit;

[0046] The state of charge maintenance module is used to adjust the power of each phase according to the three-phase voltage data to achieve the state of charge maintenance of the distributed energy storage if the state of charge of the distributed energy storage meets the maintenance conditions formed by the dynamic maintenance state of charge value during the process of voltage management of the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit.

[0047] The technical solution adopted by the present invention to solve its technical problem is: to provide an electronic device, including a memory, a processor and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the steps of the distribution network substation voltage management method involving the above-mentioned substation distributed energy storage are implemented.

[0048] The technical solution adopted by the present invention to solve its technical problem is: providing a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of the distribution network substation voltage management method involving the above-mentioned substation distributed energy storage are implemented.

[0049] Beneficial effects:

[0050] Due to the adoption of the above-mentioned technical scheme, the present invention has the following advantages and positive effects compared with the prior art: the present invention makes full use of the active regulation capability of the distributed energy storage in the substation, collects the voltage data of the distributed energy storage grid connection point in the substation, considers the historical voltage over-limit situation of the distribution network substation, customizes the substation energy storage control strategy, and performs dynamic real-time phase management of the substation voltage to achieve the distribution network substation voltage optimization control. Compared with the existing scheme, there is no need to transform the distribution network lines, distribution transformers, limit the access of distributed photovoltaics and their active output, thereby efficiently, economically and comprehensively managing the voltage over-limit problem in the distribution network substation and improving the voltage quality in the substation. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Schematic diagram of the control architecture of the method for voltage management in a distribution network area according to the first embodiment of the present invention;

[0052] Figure 2 It is a flow chart of a method for voltage management in a distribution network area according to a first embodiment of the present invention;

[0053] Figure 3 is a flow chart of voltage management in the first embodiment of the present invention;

[0054] Figure 4 is a flow chart of charge state maintenance in the first embodiment of the present invention;

[0055] Figure 5 It is a flow chart of determining a dynamic maintenance state of charge value in a first embodiment of the present invention. DETAILED DESCRIPTION

[0056] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0057] The first embodiment of the present invention relates to a method for voltage management in a distribution network area with the participation of distributed energy storage in the area. The method can be based on Figure 1 The control architecture shown in the figure is implemented. This method makes full use of the active regulation capability of the distributed energy storage in the substation, collects the voltage data of the distributed energy storage grid connection point in the substation, considers the historical voltage over-limit situation of the distribution network substation, customizes the substation energy storage control strategy, and performs dynamic real-time phase management of the substation voltage to achieve the distribution network substation voltage optimization control. There is no need to transform the distribution network lines, adjust the distribution transformer gears, limit the access of distributed photovoltaics and their active output and other traditional solutions, so as to efficiently, economically and comprehensively manage the voltage over-limit problem in the distribution network substation and improve the voltage quality in the substation.

[0058] like Figure 2 As shown, the method for voltage management in a distribution network area with the participation of distributed energy storage in the area of ​​this embodiment specifically includes the following steps:

[0059] Step 1: Obtain the three-phase voltage data of the distributed energy storage grid connection point in the distribution network area.

[0060] In this step, the real-time data U of the three-phase voltage of the distributed energy storage grid connection point in the distribution network area is first obtained. a , U b and U c , then, the upper limit governance target value U up_set , over the lower limit governance target value U low_set , Dead zone value U db , Voltage over-limit management power adjustment step length P set , distributed energy storage charging prohibition SOC value in the substation (90%), distributed energy storage discharging prohibition SOC value in the substation (20%), distributed energy storage maintenance SOC value SOC mt , Distributed energy storage maintenance SOC dead zone value SOC db to set it up.

[0061] Step 2: When one phase voltage data or multiple phase voltage data in the three-phase voltage data exceeds the voltage limit, voltage management is performed on the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the voltage limit.

[0062] In this step, if the real-time data U obtained in step 1 a , U b and U cThere is a real-time data greater than the upper limit governance target value U up_set , or less than the lower limit governance target value U low_set , it means that the voltage exceeds the limit. At this time, it is necessary to manage the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit.

[0063] For ease of understanding, the following definitions are made here: "SOC charging maintenance flag = 0" indicates that the distributed energy storage is not in the SOC charging maintenance state, "SOC charging maintenance flag = 1" indicates that the distributed energy storage is in the SOC charging maintenance state, "SOC discharge maintenance flag = 0" indicates that the distributed energy storage is not in the SOC discharge maintenance state, and "SOC discharge maintenance flag = 1" indicates that the distributed energy storage is in the SOC discharge maintenance state. When "SOC charging maintenance flag = 0" and "SOC discharge maintenance flag = 0", it means that the distributed energy storage is not in the SOC maintenance state, and when "SOC charging maintenance flag = 1" or "SOC discharge maintenance flag = 1", it means that the distributed energy storage is in the SOC maintenance state.

[0064] like Figure 3 As shown, the specific steps for managing the three-phase voltage at the distributed energy storage grid connection point are as follows:

[0065] (1) Phase A treatment steps:

[0066] 1) Determine U a >U up_set Whether it is established (i.e., whether the voltage of phase A exceeds the upper limit control target value), and whether the distributed energy storage in the substation is not in a charging prohibition state at this time;

[0067] 2) If all conditions in step 1) are met, let the A-phase power P of the distributed energy storage in the substation be a Subtract a voltage over-limit management power adjustment step, that is: P a =P a -P set , then execute step 3). If the conditions in step 1) are not met, execute step 3 directly);

[0068] 3) Determine U a >U low_set (i.e., the voltage of phase A exceeds the lower limit control target value), U a up_set -U db (i.e., the A-phase voltage is less than the difference between the upper limit control target value and the dead zone value) and the A-phase power P of the distributed energy storage in the substation area a <0, whether these three conditions are met at the same time;

[0069] ​4) If the conditions of step 3) are met at the same time, go directly to step 5); if any condition of step 3) is not met, skip step 5) and go directly to step 6);

[0070] 5) Determine whether the two conditions, SOC charging maintenance flag = 0 and SOC discharging maintenance flag = 0, are met (i.e., determine whether the distributed energy storage is not in the state of charge maintenance state). If both conditions are met, set the power P of the phase A of the distributed energy storage in the substation area. a Add a voltage over-limit management power adjustment step, that is: P a =P a +P set , then execute step 6), if the two conditions of SOC charging maintenance flag bit = 0 and SOC discharging maintenance flag bit = 0 are not met, directly execute step 6);

[0071] 6) Determine U a low_set Whether it is established (determine whether the voltage of phase A is less than the lower limit control target value), and whether the distributed energy storage in the substation is not in a prohibited state at this time;

[0072] 7) If all conditions in step 6) are met, let the phase A power P of the distributed energy storage in the substation be a Add a voltage over-limit management power adjustment step, that is: P a =P a +P set , then execute step 8). If the conditions in step 6) are not met, execute step 8 directly);

[0073] 8) Judge U a up_set (A phase voltage is less than the upper limit control target value), U a >U low_set +U db (Phase A voltage is greater than the sum of the upper limit control target value and the dead zone value) and Phase A power P a >0Whether these three conditions are met at the same time;

[0074] 9) If the conditions of step 8) are met at the same time, then directly proceed to step 10). If any condition of step 8) is not met, then skip step 10) and end this round of the process directly;

[0075] 10) Determine whether the two conditions, SOC charging maintenance flag = 0 and SOC discharging maintenance flag = 0, are met (i.e., determine whether the distributed energy storage is in the state of charge maintenance state). If both conditions are met, set the power P of the phase A of the distributed energy storage in the substation area. a Subtract a voltage over-limit management power adjustment step, that is: P a =P a -P​​set , and then end this round of process. If the two conditions of SOC charging maintenance flag = 0 and SOC discharging maintenance flag = 0 are not met, then end this round of process directly.

[0076] (2) Phase B treatment steps:

[0077] 1) Determine U b >U up_set Is it true, and whether the distributed energy storage in the substation is not in a charging prohibition state at this time;

[0078] 2) If all the conditions in step 1) are met, first set the power P of phase B of the distributed energy storage in the substation area. b Execution: P b =P b -P set , then execute step 3). If the conditions in step 1) are not met, execute step 3 directly);

[0079] 3) Determine U b >U low_set , U b up_set -U db and P b <0Whether these three conditions are met at the same time;

[0080] 4) If the conditions of step 3) are met at the same time, go directly to step 5); if any condition of step 3) is not met, skip step 5) and go directly to step 6);

[0081] 5) Determine whether the two conditions, SOC charging maintenance flag = 0 and SOC discharging maintenance flag = 0, are met. If both conditions are met, first set the power P of the phase B of the distributed energy storage in the substation area. b Execution: P b =P b +P set , then execute step 6), if the two conditions of SOC charging maintenance flag bit = 0 and SOC discharging maintenance flag bit = 0 are not met, directly execute step 6);

[0082] 6) Determine U b low_set Is it true, and whether the distributed energy storage in the substation is not in a prohibited state at this time;

[0083] 7) If all conditions in step 6) are met, first set the power P of phase B of the distributed energy storage in the substation area. b Execution: P b =P b +P set , then execute step 8). If the conditions in step 6) are not met, execute step 8 directly);​​

[0084] 8) Judge U b up_set , U b >U low_set +U db and P b >0Whether these three conditions are met at the same time;

[0085] 9) If the conditions of step 8) are met at the same time, then directly proceed to step 10). If any condition of step 8) is not met, then skip step 10) and end this round of the process directly;

[0086] 10) Determine whether the two conditions, SOC charging maintenance flag = 0 and SOC discharging maintenance flag = 0, are met. If both conditions are met, first set the power P of the phase B of the distributed energy storage in the substation area. b Execution: P b =P b -P set , and then end this round of process. If the two conditions of SOC charging maintenance flag = 0 and SOC discharging maintenance flag = 0 are not met, then end this round of process directly.

[0087] (3) C phase treatment steps:

[0088] 1) Determine U c >U up_set Is it true, and whether the distributed energy storage in the substation is not in a charging prohibition state at this time;

[0089] 2) If all conditions in step 1) are met, first set the power P of phase C of the distributed energy storage in the substation area. c Execution: P c =P c -P set , then execute step 3). If the conditions in step 1) are not met, execute step 3 directly);

[0090] 3) Determine U c >U low_set , U c up_set -U db and P c <0Whether these three conditions are met at the same time;

[0091] 4) If the conditions of step 3) are met at the same time, go directly to step 5); if any condition of step 3) is not met, skip step 5) and go directly to step 6);

[0092] 5) Determine whether the two conditions, SOC charging maintenance flag = 0 and SOC discharging maintenance flag = 0, are met. If both conditions are met, first set the power P of the C phase of the distributed energy storage in the substation area.​​c Execution: P c =P c +P set , then execute step 6), if the two conditions of SOC charging maintenance flag bit = 0 and SOC discharging maintenance flag bit = 0 are not met, directly execute step 6);

[0093] 6) Determine U c low_set Is it true, and whether the distributed energy storage in the substation is not in a prohibited state at this time;

[0094] 7) If all conditions in step 6) are met, first set the power P of phase C of the distributed energy storage in the substation area. c Execution: P c =P c +P set , then execute step 8). If the conditions in step 6) are not met, execute step 8 directly);

[0095] 8) Judge U c up_set , U c >U low_set +U db and P c >0Whether these three conditions are met at the same time;

[0096] 9) If the conditions of step 8) are met at the same time, then directly proceed to step 10). If any condition of step 8) is not met, then skip step 10) and end this round of the process directly;

[0097] 10) Determine whether the two conditions, SOC charging maintenance flag = 0 and SOC discharging maintenance flag = 0, are met. If both conditions are met, first set the power P of the C phase of the distributed energy storage in the substation area. c Execution: P c =P c -P set , and then end this round of process. If the two conditions of SOC charging maintenance flag = 0 and SOC discharging maintenance flag = 0 are not met, then end this round of process directly.

[0098] In this embodiment, steps 1) to 10) in the three-phase voltage management steps of the distributed energy storage grid-connected points A, B, and C are a cyclic process. After step 10) is executed, it will wait for 1.8 seconds to execute step 1) again, and the three-phase voltage management processes of A, B, and C are parallel processes and do not interfere with each other.

[0099] ​​Step 3, in the process of voltage management of the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit, if the charge state of the distributed energy storage meets the maintenance conditions formed by the dynamic maintenance charge state value, the power of each phase is adjusted according to the three-phase voltage data to achieve charge state maintenance of the distributed energy storage.

[0100] In this step, the phase power is adjusted according to the state of charge of the distributed energy storage and the three-phase voltage data, so as to achieve the effect of maintaining the system SOC value, so that the energy storage device in the substation can control the voltage limit problem for a longer time, such as Figure 4 As shown, the specific SOC maintenance steps are as follows:

[0101] (1) SOC maintenance condition judgment:

[0102] 1) Determine SOC>SOC mt +SOC db and whether the two conditions of SOC discharge maintenance flag bit = 0 are satisfied (determine whether the state of charge of the distributed energy storage is greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in the state of charge discharge maintenance state). If so, the SOC discharge maintenance flag bit is set to 1, that is, the distributed energy storage enters the state of charge discharge maintenance state. If any condition is not satisfied, execute step 2);

[0103] 2) Determine SOC <SOC mt -SOC db and SOC charging maintenance flag bit = 0. These two conditions are met (determine whether the state of charge of the distributed energy storage is less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in the state of charge charging maintenance state). If so, the SOC charging maintenance flag bit is set to 1, that is, the distributed energy storage enters the state of charge charging maintenance state; if any of the conditions are not met, execute step 3);

[0104] 3) Determine whether at least one of the two conditions, SOC discharge maintenance flag bit = 1 and SOC charge maintenance flag bit = 1, is met (i.e., determine whether the distributed energy storage is in the state of charge charge maintenance state or the state of charge discharge maintenance state). If at least one of the conditions is met, then the following steps (2), (3) and (4) are executed simultaneously. If both conditions are not met, then directly execute step (5).

[0105] (2) Phase A voltage maintenance steps:

[0106] 1) Determine U a up_set -U db , U a >U low_set ​And whether the three conditions of SOC discharge maintenance flag bit = 1 are all met (determine whether the A phase voltage is less than the difference between the upper limit management target value and the dead zone value and greater than the lower limit management target value, and whether the distributed energy storage is in the state of charge discharge maintenance state);

[0107] 2) If all the conditions in step 1) are met, let the phase A power P of the energy storage device in the substation be a Add a voltage over-limit management power adjustment step, that is: P a =P a +P set , then execute step 3). If the conditions in step 1) are not met, execute step 3 directly);

[0108] 3) Determine U a >U low_set +U db , U a up_set And whether the three conditions of SOC charging maintenance flag bit = 1 are met (determine whether the A-phase voltage is greater than the sum of the lower limit management target value and the dead zone value and less than the upper limit management target value, and whether the distributed energy storage is in the state of charge charging maintenance state);

[0109] 4) If all conditions in step 3) are met, let the phase A power P of the energy storage device in the substation be a Subtract a voltage over-limit management power adjustment step, that is: P a =P a -P set , then execute step (5). If the conditions in step 3) are not met, execute step (5) directly.

[0110] (3) Phase B voltage maintenance steps:

[0111] 1) Determine U b up_set -U db , U b >U low_set And whether the SOC discharge maintenance flag bit = 1 and these three conditions are met;

[0112] 2) If all the conditions in step 1) are met, first set the power P of phase B of the energy storage device in the substation b Execution: P b =P b +P set , then execute step 3). If the conditions in step 1) are not met, execute step 3 directly);

[0113] 3) Determine U b >U low_set +U db , U b ​​up_set And whether the SOC charging maintenance flag bit = 1 and these three conditions are met;

[0114] 4) If all conditions in step 3) are met, first set the power P of phase B of the energy storage device in the substation b Execution: P b =P b -P set , then execute step (5). If the conditions in step 3) are not met, execute step (5) directly.

[0115] (4) C phase voltage maintenance steps:

[0116] 1) Determine U c up_set -U db , U c >U low_set And whether the SOC discharge maintenance flag bit = 1 and these three conditions are met;

[0117] 2) If all conditions in step 1) are met, first set the power P of phase C of the energy storage device in the substation c Execution: P c =P c +P set , then execute step 3). If the conditions in step 1) are not met, execute step 3 directly);

[0118] 3) Determine U c >U low_set +U db , U c up_set And whether the SOC charging maintenance flag bit = 1 and these three conditions are met;

[0119] 4) If all conditions in step 3) are met, first set the power P of phase C of the energy storage device in the substation c Execution: P c =P c -P set , then execute step (5). If the conditions in step 3) are not met, execute step (5) directly.

[0120] (5) SOC maintenance completion judgment:

[0121] 1) Determine whether the state of charge of the distributed energy storage is equal to the dynamic maintenance state of charge value, that is, SOC=SOC mt whether it is satisfied;

[0122] ​​​2) If the conditions in step 1) are met, the SOC discharge maintenance flag and the SOC charge maintenance flag are all set to zero, that is, the distributed energy storage exits the state of charge discharge maintenance state and the state of charge charge maintenance state, and then the SOC maintenance process ends. If the conditions in step 1) are not met, the SOC maintenance process ends directly.

[0123] In this embodiment, the distributed energy storage SOC maintenance steps (1) to (5) are a cyclic process. After step (5) is executed, it will wait for 1.8 seconds before executing step (1) again, and steps (2), (3), and (4) are parallel steps.

[0124] Since the charging and discharging requirements of distributed energy storage for voltage over-limit control vary at different times, if a static maintenance SOC value SOCmt is set, the available charging and discharging capacity of distributed energy storage during peak and valley periods may not meet the actual charging and discharging requirements, resulting in the problem that when the voltage exceeds the limit in the substation, the distributed energy storage is in a state of charging and discharging prohibition and cannot be effectively controlled. Therefore, in order to improve the effective utilization rate of distributed energy storage, the maintenance SOC value SOC of distributed energy storage at different time points should be adjusted regularly in combination with the dynamic change characteristics of the load. mt , and realize the dynamic adjustment of energy storage SOC with load changes. This implementation method extracts the load demand characteristics of the substation and the charging and discharging rules of distributed energy storage by sampling and analyzing the historical operation data set of distributed energy storage, and combines the exhaustive optimization method to carry out the distributed energy storage dynamic maintenance SOC value SOC mt The settings, such as Figure 5 As shown, the specific steps are as follows:

[0125] (1) Statistics of historical charge and discharge data of distributed energy storage: Extract the charge and discharge data of distributed energy storage in the past seven days, divide the data into seven days by date, and then divide the daily data into 24 segments by time, and obtain the charge and discharge amount in each hour of each day in the past seven days. The expression is as follows:

[0126] ;

[0127] In the formula, E d,h,ch is the total charging capacity of distributed energy storage in the hth time period on the dth day, kWh; P d,h,i,ch is the charging power of the distributed energy storage at the i-th data point in the h-th time period on the d-th day, kW; E d,h,dis is the total discharge of distributed energy storage in the hth time period on the dth day, kWh; P d,h,i,dis is the discharge power of the distributed energy storage at the i-th data point in the h-th time period on the d-th day, kW; n is the number of data sampling points of the energy storage device within 1 hour.

[0128] (2) Extract the typical charging and discharging demand characteristics of distributed energy storage: Compare the charging and discharging data of distributed energy storage in the same time period in the past seven days, and find the maximum charging capacity E that has occurred in each time period. ch,max and discharge capacity E dis,max , the maximum charge E ch,max As the charging demand of the distributed energy storage in the substation, the maximum discharge capacity E dis,max As the discharge demand of distributed energy storage in the substation, it can be expressed as:

[0129] ;

[0130] In the formula, E ch,max Charging demand for distributed energy storage in the substation area; E d,1,ch , E d,2,ch , ..., E d,24,ch They represent the charging capacity of distributed energy storage in the 1st, 2nd to 24th hours on the dth day, kWh; E dis,max E is the discharge demand of distributed energy storage in the substation area; d,1,dis , E d,2,dis , ..., E d,24,dis They represent the discharge amount of distributed energy storage in the 1st, 2nd to 24th hours on the dth day, kWh.

[0131] (3) The extracted charging demand and discharging demand of the distributed energy storage in the substation are divided by the rated installed capacity of the distributed energy storage in the substation to obtain the typical SOC change, which is expressed as:

[0132] ;

[0133] In the formula, SOC up , SOC down are the combined sequences of the typical SOC growth and reduction of distributed energy storage in each hour; SOC 1,up , SOC 2,up , ..., SOC 24,up It indicates the SOC growth of distributed energy storage in the first, second, ... 24th hour; SOC 1,down , SOC 2,down , ..., SOC 24,down It indicates the reduction of SOC of distributed energy storage in the first, second, ... 24th hour; E rated is the rated installed capacity of distributed energy storage, kWh.

[0134] (4) Constructing the operation scenario of the energy storage device: setting different charge states for the initial operation time (zero point) of the distributed energy storage, and generating a series of distributed energy storage operation scenarios {SOC0} based on the different charge states at the initial operation time of the distributed energy storage, specifically: taking the forbidden charging SOC value (90%) of the distributed energy storage in the substation as the upper limit SOC max , the prohibited SOC value (20%) is the lower limit SOC of the interval min , set the SOC growth step SOC step , according to the step size from SOC min Increment to SOC max Generate a series of zero-time SOC initial values ​​SOC0, expressed as:

[0135] ;

[0136] (5) Calculate the SOC value of the energy storage device at different time nodes in each scenario: Take the elements in SOC0 as the initial state of the energy storage device in different scenarios, and combine the typical SOC change characteristics of the energy storage in the substation SOC up With SOC down , calculate the SOC value SOC of the energy storage device at each time point in each scenario i,t , expressed as:

[0137] ;

[0138] In the formula, SOC i,t , SOC i,t+1 They represent the SOC values ​​of distributed energy storage at the tth time point and the t+1th time point in the i-th scenario respectively; SOC i,t,up , SOC i,t,down They respectively represent the increase and decrease of distributed energy storage SOC at the tth time point in the i-th scenario.

[0139] (6) Determine the SOC value at each time point in each scene i,t Limit exceeded: If all SOC values ​​calculated in scenario i meet SOC min <SOC i,t <SOC max , it indicates that the distributed energy storage operation curve of scenario i meets the load demand of the substation, and the initial SOC value set for scenario i is retained; if SOC i,t <SOC min or SOC i,t >SOC max , it means that the initial SOC value set for this scenario does not meet the requirements, and the initial value of scenario i is excluded.

[0140] (7) After the elimination screening in step (6), the remaining scenarios are regarded as feasible scenarios for the operation of the energy storage device. The scenario corresponding to the median SOC0 is selected from the feasible scenarios as the optimal scenario for the energy storage operation. The SOC value SOC at each time point on the SOC curve under this optimal scenario is i,t That is, to dynamically maintain the SOC value SOC mt .

[0141] It is not difficult to find that this implementation method makes full use of the active regulation capability of the distributed energy storage in the substation, collects the voltage data of the distributed energy storage grid connection point in the substation, considers the historical voltage over-limit situation of the distribution network substation, customizes the substation energy storage control strategy, and performs dynamic real-time phase management of the substation voltage to achieve the distribution network substation voltage optimization control. Compared with the existing scheme, there is no need to transform the distribution network lines, distribution transformers, limit the access of distributed photovoltaics and their active output, thereby efficiently, economically and comprehensively managing the voltage over-limit problem in the distribution network substation and improving the voltage quality in the substation.

[0142] The second embodiment of the present invention relates to a distribution network area voltage management system in which distributed energy storage in the area participates, comprising:

[0143] An acquisition module is used to obtain three-phase voltage data of distributed energy storage grid connection points in the distribution network area;

[0144] A voltage management module is used to manage the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit when one phase voltage data or multiple phase voltage data in the three-phase voltage data exceeds the limit;

[0145] The state of charge maintenance module is used to adjust the power of each phase according to the three-phase voltage data to achieve the state of charge maintenance of the distributed energy storage if the state of charge of the distributed energy storage meets the maintenance conditions formed by the dynamic maintenance state of charge value during the process of voltage management of the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit.

[0146] The voltage management module comprises:

[0147] The first judgment unit is used to judge whether the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the upper limit control target value, and whether the distributed energy storage is not in a charging prohibition state;

[0148] The first management unit is used to subtract a voltage over-limit management power adjustment step from the corresponding phase power of the distributed energy storage when the phase voltage of the distributed energy storage grid-connected point where the voltage over-limit situation exists exceeds the over-limit management target value and the distributed energy storage is not in a charging prohibition state.

[0149] The voltage management module also includes:

[0150] The second judgment unit is used to judge whether the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the lower limit governance target value and is less than the difference between the upper limit governance target value and the dead zone value, and whether the corresponding phase power of the distributed energy storage is less than zero when the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the upper limit governance target value does not exceed the upper limit governance target value, or the distributed energy storage is in a charging prohibited state;

[0151] A third judgment unit is used to judge whether the distributed energy storage is in a state of charge maintenance state when the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the lower limit governance target value and is less than the difference between the upper limit governance target value and the dead zone value, and the corresponding phase power of the distributed energy storage is less than zero;

[0152] The second management unit is used to increase the phase power of the corresponding distributed energy storage by a voltage over-limit management power adjustment step when the distributed energy storage is not in the charge state maintenance state.

[0153] The voltage management module also includes:

[0154] The fourth judgment unit is used to judge whether the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit is less than the lower limit governance target value, or is not less than the difference between the upper limit governance target value and the dead zone value, or the corresponding phase power of the distributed energy storage is greater than zero, or the distributed energy storage is in the state of charge maintenance state, and whether the distributed energy storage is not in a prohibited state;

[0155] The third management unit is used to increase the phase power of the corresponding distributed energy storage by a voltage over-limit management power adjustment step when the phase voltage of the distributed energy storage grid-connected point where the voltage over-limit situation exists is less than the lower limit management target value, and the distributed energy storage is not in a prohibited state.

[0156] The voltage management module also includes:

[0157] A fifth judgment unit is used to judge whether the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit is less than the upper limit governance target value and greater than the sum of the upper limit governance target value and the dead zone value, and whether the corresponding phase power of the distributed energy storage is greater than zero when the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit is not less than the lower limit governance target value, or the distributed energy storage is in a prohibited state;

[0158] A sixth judgment unit is used to judge whether the distributed energy storage is in a state of charge maintenance state when the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit is less than the upper limit governance target value and greater than the sum of the upper limit governance target value and the dead zone value, and the corresponding phase power of the distributed energy storage is greater than zero;

[0159] The fourth management unit is used to subtract a voltage over-limit management power adjustment step from the corresponding phase power of the distributed energy storage when the distributed energy storage is not in the state of charge maintenance state.

[0160] The state of charge maintenance module includes:

[0161] A first maintenance condition judgment unit, used to judge whether the state of charge of the distributed energy storage is greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in a state of charge discharge maintenance state;

[0162] A first execution unit, configured to, when the state of charge of the distributed energy storage is greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and the distributed energy storage is not in the state of charge discharge maintenance state, enable the distributed energy storage to enter the state of charge discharge maintenance state;

[0163] The second maintenance condition judgment unit is used to judge whether the state of charge of the distributed energy storage is less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in the state of charge charging maintenance state when the state of charge of the distributed energy storage is not greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, or the distributed energy storage is in the state of charge discharge maintenance state;

[0164] The second execution unit is used to make the distributed energy storage enter the state of charge charging maintenance state when the state of charge of the distributed energy storage is less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and the distributed energy storage is not in the state of charge charging maintenance state;

[0165] A maintenance state judgment unit, used to judge whether the distributed energy storage is in a state of charge charging maintenance state or a state of charge discharging maintenance state when the state of charge of the distributed energy storage is not less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, or when the distributed energy storage is in a state of charge charging maintenance state;

[0166] A power adjustment unit, used to adjust the power of each phase according to the three-phase voltage data when the distributed energy storage is in a state-of-charge charging maintenance state or a state-of-charge discharging maintenance state;

[0167] A maintenance completion judgment unit, used to judge whether the state of charge of the distributed energy storage is equal to the dynamic maintenance state of charge value when the distributed energy storage is not in the state of charge charging maintenance state and is not in the state of charge discharging maintenance state;

[0168] The exit unit is used to make the distributed energy storage exit the state of charge discharge maintenance state and the state of charge charging maintenance state when the state of charge of the distributed energy storage is equal to the dynamic maintenance state of charge value.

[0169] The power adjustment unit comprises:

[0170] The first voltage judgment subunit is used to judge whether the phase voltage of the distributed energy storage grid connection point is less than the difference between the upper limit management target value and the dead zone value and greater than the lower limit management target value, and whether the distributed energy storage is in a state of charge discharge maintenance state;

[0171] The first maintenance execution subunit is used to increase the phase power of the corresponding distributed energy storage by a voltage over-limit management power adjustment step when the phase voltage of the distributed energy storage grid connection point is less than the difference between the over-limit management target value and the dead zone value and greater than the over-limit management target value, and the distributed energy storage is in a state of charge discharge maintenance state;

[0172] The second voltage judgment subunit is used to judge whether the phase voltage of the distributed energy storage grid connection point is greater than the sum of the lower limit management target value and the dead zone value and less than the upper limit management target value, and whether the distributed energy storage is in a state of charge charging maintenance state;

[0173] The second maintenance execution subunit is used to subtract a voltage over-limit management power adjustment step from the corresponding phase power of the distributed energy storage when the phase voltage of the distributed energy storage grid-connected point is greater than the sum of the lower limit management target value and the dead zone value and less than the upper limit management target value, and the distributed energy storage is in the charged state and charging maintenance state.

[0174] The dynamic maintenance state of charge value is determined by:

[0175] Extract the operating charge and discharge data of the distributed energy storage in the past K days, and segment the operating charge and discharge data in the past K days according to date and time to obtain the charge and discharge amount in each time period of each day in the past K days; where K is an integer greater than 1;

[0176] Compare the charging and discharging amounts of distributed energy storage in the same period of time in the past K days, take the maximum charging amount in each period as the charging demand of each period, and take the maximum discharging amount in each period as the discharging demand of each period;

[0177] Divide the charging demand and discharging demand of each period by the rated installed capacity of the distributed energy storage to obtain the change in the state of charge of each period;

[0178] Setting different charge states at the initial moment of operation of the distributed energy storage, and generating a series of distributed energy storage operation scenarios based on the different charge states at the initial moment of operation of the distributed energy storage;

[0179] According to different distributed energy storage operation scenarios, combined with the charge state changes in each period, the charge state of distributed energy storage at each time point in each operation scenario is calculated;

[0180] Filter out the operating scenarios where the state of charge at each time point is between the prohibited charging state of charge value and the prohibited discharging state of charge value;

[0181] From the screened operating scenarios, find the operating scenario corresponding to the median state of charge at the initial moment, and use the state of charge at each time point under the operating scenario as the maintenance state of charge value at each time point.

[0182] The third embodiment of the present invention relates to an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for voltage management in a distribution network substation involving distributed energy storage in the substation of the first embodiment when executing the computer program.

[0183] The fourth embodiment of the present invention relates to a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for voltage management in a distribution network substation involving distributed energy storage in the substation of the first embodiment.

[0184] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program codes.

[0185] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, 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 generate 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 flowchart and / or block diagram. 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.

[0186] 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 a manufactured product including an instruction method, which is implemented in the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0187] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions 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.

[0188] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for voltage management in a distribution network area with the participation of distributed energy storage in the area, characterized in that: The following steps are involved: Obtain three-phase voltage data of distributed energy storage grid connection points in distribution network areas; When one phase voltage data or multiple phase voltage data in the three-phase voltage data exceeds the voltage limit, voltage management is performed on the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the voltage limit; In the process of voltage management of the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit, if the state of charge of the distributed energy storage meets the maintenance condition formed by the dynamic maintenance state of charge value, the power of each phase is adjusted according to the three-phase voltage data to achieve the state of charge maintenance of the distributed energy storage; wherein, if the state of charge of the distributed energy storage meets the maintenance condition formed by the dynamic maintenance state of charge value, the power of each phase is adjusted according to the three-phase voltage data to achieve the state of charge maintenance of the distributed energy storage, specifically including: Determine whether the state of charge of the distributed energy storage is greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in the state of charge discharge maintenance state; If the state of charge of the distributed energy storage is greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and the distributed energy storage is not in the state of charge discharge maintenance state, the distributed energy storage is made to enter the state of charge discharge maintenance state; If the state of charge of the distributed energy storage is not greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, or the distributed energy storage is in the state of charge discharge maintenance state, then determine whether the state of charge of the distributed energy storage is less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in the state of charge charging maintenance state; If the state of charge of the distributed energy storage is less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and the distributed energy storage is not in the state of charge charging maintenance state, the distributed energy storage is made to enter the state of charge charging maintenance state; If the state of charge of the distributed energy storage is not less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, or the distributed energy storage is in the state of charge charging maintenance state, then it is determined whether the distributed energy storage is in the state of charge charging maintenance state or the state of charge discharging maintenance state; If the distributed energy storage is in the state-of-charge charging maintenance state or the state-of-charge discharging maintenance state, the power of each phase is adjusted according to the three-phase voltage data; If the distributed energy storage is not in the state of charge charging maintenance state and is not in the state of charge discharging maintenance state, determining whether the state of charge of the distributed energy storage is equal to the dynamic maintenance state of charge value; If the state of charge of the distributed energy storage is equal to the dynamic maintenance state of charge value, the distributed energy storage is exited from the state of charge discharge maintenance state and the state of charge charging maintenance state.

2. The method for voltage management in a distribution network area with the participation of distributed energy storage in the area according to claim 1 is characterized in that: The voltage management of the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit specifically includes: Determine whether the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the upper limit control target value, and whether the distributed energy storage is not in a charging prohibition state; If the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the upper limit control target value, and the distributed energy storage is not in a charging prohibition state, the corresponding phase power of the distributed energy storage will be reduced by a voltage over-limit control power adjustment step.

3. The method for voltage management in a distribution network area with the participation of distributed energy storage in the area according to claim 2 is characterized in that: If the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit does not exceed the upper limit governance target value, or the distributed energy storage is in a charging prohibited state, then determine whether the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit exceeds the lower limit governance target value and is less than the difference between the upper limit governance target value and the dead zone value, and whether the corresponding phase power of the distributed energy storage is less than zero; If the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the lower limit control target value and is less than the difference between the upper limit control target value and the dead zone value, and the corresponding phase power of the distributed energy storage is less than zero, it is determined whether the distributed energy storage is in the state of charge maintenance state; If the distributed energy storage is not in the state of charge maintenance state, the corresponding phase power of the distributed energy storage is increased by a voltage over-limit management power adjustment step.

4. The method for voltage management in a distribution network area with the participation of distributed energy storage in the area according to claim 3 is characterized in that: If the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit does not exceed the lower limit management target value, or is not less than the difference between the upper limit management target value and the dead zone value, or the corresponding phase power of the distributed energy storage is greater than zero, or the distributed energy storage is in the state of charge maintenance, then determine whether the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit is less than the lower limit management target value, and whether the distributed energy storage is not in a prohibited state; If the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit is less than the lower limit management target value, and the distributed energy storage is not in a prohibited state, the corresponding phase power of the distributed energy storage will be increased by a voltage exceeding the limit management power adjustment step.

5. The method for voltage management in a distribution network area with the participation of distributed energy storage in the area according to claim 4 is characterized in that: If the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit is not less than the lower limit management target value, or the distributed energy storage is in a prohibited state, then determine whether the phase voltage of the distributed energy storage grid-connected point where the voltage exceeds the limit is less than the upper limit management target value and greater than the sum of the upper limit management target value and the dead zone value, and whether the corresponding phase power of the distributed energy storage is greater than zero; If the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit is less than the upper limit management target value and greater than the sum of the upper limit management target value and the dead zone value, and the corresponding phase power of the distributed energy storage is greater than zero, it is determined whether the distributed energy storage is in the state of charge maintenance state; If the distributed energy storage is not in the state of charge maintenance state, the corresponding phase power of the distributed energy storage is subtracted from a voltage over-limit management power adjustment step.

6. The method for voltage management in a distribution network area with the participation of distributed energy storage in the area according to claim 1 is characterized in that: The step of adjusting the power of each phase according to the three-phase voltage data specifically includes: Determine whether the phase voltage of the distributed energy storage grid connection point is less than the difference between the upper limit management target value and the dead zone value and greater than the lower limit management target value, and whether the distributed energy storage is in the charged state discharge maintenance state; If the phase voltage of the distributed energy storage grid connection point is less than the difference between the upper limit management target value and the dead zone value and greater than the lower limit management target value, and the distributed energy storage is in the state of charge discharge maintenance state, then the corresponding phase power of the distributed energy storage is increased by a voltage over-limit management power adjustment step; Determine whether the phase voltage of the distributed energy storage grid connection point is greater than the sum of the lower limit management target value and the dead zone value and less than the upper limit management target value, and whether the distributed energy storage is in the state of charge charging maintenance state; If the phase voltage of the distributed energy storage grid-connected point is greater than the sum of the lower limit management target value and the dead zone value and is less than the upper limit management target value, and the distributed energy storage is in the charged state and charging maintenance state, then the corresponding phase power of the distributed energy storage will be subtracted from a voltage over-limit management power adjustment step.

7. The method for voltage management in a distribution network area with the participation of distributed energy storage in the area according to claim 1 is characterized in that: The dynamic maintenance state of charge value is determined by: Extract the operating charge and discharge data of the distributed energy storage in the past K days, and segment the operating charge and discharge data in the past K days according to date and time to obtain the charge and discharge amount in each time period of each day in the past K days; where K is an integer greater than 1; Compare the charging and discharging amounts of distributed energy storage in the same period of time in the past K days, take the maximum charging amount in each period as the charging demand of each period, and take the maximum discharging amount in each period as the discharging demand of each period; Divide the charging demand and discharging demand of each period by the rated installed capacity of the distributed energy storage to obtain the change in the state of charge of each period; Setting different charge states at the initial moment of operation of the distributed energy storage, and generating a series of distributed energy storage operation scenarios based on the different charge states at the initial moment of operation of the distributed energy storage; According to different distributed energy storage operation scenarios, combined with the charge state changes in each period, the charge state of distributed energy storage at each time point in each operation scenario is calculated; Filter out the operating scenarios where the state of charge at each time point is between the prohibited charging state of charge value and the prohibited discharging state of charge value; From the screened operating scenarios, find the operating scenario corresponding to the median state of charge at the initial moment, and use the state of charge at each time point under the operating scenario as the maintenance state of charge value at each time point.

8. A distribution network area voltage management system involving distributed energy storage in the area, characterized in that: include: An acquisition module is used to obtain three-phase voltage data of distributed energy storage grid connection points in the distribution network area; A voltage management module is used to manage the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit when one phase voltage data or multiple phase voltage data in the three-phase voltage data exceeds the limit; The state of charge maintenance module is used to adjust the power of each phase according to the three-phase voltage data to achieve the state of charge maintenance of the distributed energy storage in the process of voltage management of the phase voltage of the distributed energy storage grid connection point where the voltage exceeds the limit, if the state of charge of the distributed energy storage meets the maintenance conditions formed by the dynamic maintenance state of charge value; The state of charge maintenance module includes: A first maintenance condition judgment unit, used to judge whether the state of charge of the distributed energy storage is greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in a state of charge discharge maintenance state; A first execution unit, configured to, when the state of charge of the distributed energy storage is greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and the distributed energy storage is not in the state of charge discharge maintenance state, enable the distributed energy storage to enter the state of charge discharge maintenance state; The second maintenance condition judgment unit is used to judge whether the state of charge of the distributed energy storage is less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and whether the distributed energy storage is not in the state of charge charging maintenance state when the state of charge of the distributed energy storage is not greater than the sum of the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, or the distributed energy storage is in the state of charge discharge maintenance state; The second execution unit is used to make the distributed energy storage enter the state of charge charging maintenance state when the state of charge of the distributed energy storage is less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, and the distributed energy storage is not in the state of charge charging maintenance state; A maintenance state judgment unit, used to judge whether the distributed energy storage is in a state of charge charging maintenance state or a state of charge discharging maintenance state when the state of charge of the distributed energy storage is not less than the difference between the dynamic maintenance state of charge value and the maintenance state of charge dead zone value, or when the distributed energy storage is in a state of charge charging maintenance state; A power adjustment unit, used to adjust the power of each phase according to the three-phase voltage data when the distributed energy storage is in a state-of-charge charging maintenance state or a state-of-charge discharging maintenance state; A maintenance completion judgment unit, used to judge whether the state of charge of the distributed energy storage is equal to the dynamic maintenance state of charge value when the distributed energy storage is not in the state of charge charging maintenance state and is not in the state of charge discharging maintenance state; The exit unit is used to make the distributed energy storage exit the state of charge discharge maintenance state and the state of charge charging maintenance state when the state of charge of the distributed energy storage is equal to the dynamic maintenance state of charge value.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method for voltage management in a distribution network substation involving distributed energy storage in the substation are implemented as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, the steps of the method for voltage management in a distribution network substation involving distributed energy storage in the substation are implemented as described in any one of claims 1-7.

Images