Automatic voltage control method based on EMS and computer system

Abstract

The invention belongs to the technical field of voltage control, and particularly relates to an automatic voltage control method based on an EMS and a computer system. Different from the prior art according to the SOC upper and lower limits of the energy storage device in a fixed ideal state, the SOC upper and lower limits of the energy storage device can be dynamically adjusted according to the health state of the energy storage device and / or the power grid load, the service life of the energy storage device can be prolonged, aging equipment is prevented from being in a high SOC state for a long time, and battery attenuation is reduced; the output upper limit is dynamically adjusted according to the power grid state, and the overload risk is prevented; and balance between power grid requirements and equipment health is realized, and the overall operation and maintenance cost is reduced. The technical problem that an existing AVC control method is high in operation and maintenance cost is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of voltage control, and in particular relates to an automatic voltage control method and a computer system based on EMS. Background Art

[0002] Traditional AVC (Automatic Voltage Control) systems play a vital role in power systems. However, existing AVC systems rely primarily on preset control rules and fixed sensitivity parameters, making them difficult to adapt to the rapidly changing grid operating conditions and complex and diverse operating environments. The development of smart grids is placing higher demands on the accuracy and response speed of grid voltage control.

[0003] The existing application publication number is CN111969615A, and the publication date of the Chinese invention patent application is 2020.11.20. The published text discloses a control method for a storage power station to smooth the voltage fluctuation of the power grid. When the real-time voltage does not meet the preset voltage requirement, the method determines the required reactive power according to the real-time voltage and the preset voltage requirement, and then controls the PCS (Power Conversion System, energy storage converter) and SVG (Static Var Generator) to output the required reactive power. When the PCS performs reactive power distribution, the reactive power that each PCS needs to output is distributed according to the ratio of the maximum SOC (State of Charge) that the PCS can output to the maximum SOC that all PCS can output. However, when the above scheme performs reactive power distribution, the upper and lower limits of the SOC of each PCS are both ideal 1 and 0. When adjusting, the energy storage equipment is always operated at full load, which not only accelerates the aging of the energy storage equipment and increases equipment loss; there is also the risk of overload, which leads to energy efficiency waste. Therefore, there is a problem of high operation and maintenance costs in the prior art. Summary of the Invention

[0004] The purpose of the present invention is to provide an automatic voltage control method and computer system based on EMS to solve the technical problem of high operation and maintenance cost in the existing AVC control method.

[0005] To solve the above technical problems, the present invention provides a technical solution of an automatic voltage control method based on EMS: an automatic voltage control method based on EMS, the method comprising:

[0006] S1. Determine the reactive power deviation that needs to be adjusted;

[0007] S2. Allocate the reactive power deviation to each reactive power regulation device involved in reactive power regulation, so that each reactive power regulation device outputs according to the allocation result; the reactive power regulation device includes a PCS; the reactive power deviation allocated to each PCS is determined based on the current SOC and the upper and lower limits of the SOC of the energy storage device corresponding to the PCS; the upper and lower limits of the SOC are determined based on (1) and / or (2):

[0008] (1) When the energy storage device needs to be charged, the worse the health state of the energy storage device is, the lower the SOC upper limit of the energy storage device is; when the energy storage device needs to be discharged, the worse the health state of the energy storage device is, the higher the SOC lower limit of the energy storage device is;

[0009] (2) When the energy storage device needs to be charged, the worse the grid state is, the higher the SOC upper limit of the energy storage device is; when the energy storage device needs to be discharged, the worse the grid state is, the lower the SOC lower limit of the energy storage device is.

[0010] The beneficial effect of the above technical solution is that the technical solution of the automatic voltage control method based on EMS of the present invention belongs to an improved invention. Different from the existing technology that is based on the upper and lower limits of the SOC of the energy storage device under fixed ideal conditions, the present invention can dynamically adjust the upper and lower limits of the SOC of the energy storage device according to the health status of the energy storage device and / or the grid load, and can extend the life of the energy storage device: avoid aging equipment in a high SOC state for a long time, reduce battery attenuation; improve system reliability, dynamically adjust the output upper limit according to the grid status, and prevent overload risks; achieve a balance between grid demand and equipment health, and reduce overall operation and maintenance costs. The present invention solves the technical problem of high operation and maintenance costs in existing AVC control methods.

[0011] Furthermore, the health status is evaluated by the health index: the health index is divided into levels representing different health status according to the size; the health index H i According to the following formula:

[0012] H i =A / (CC×IR)

[0013] Wherein, CC is the number of cycles of the energy storage device, IR is the change of the current internal resistance of the energy storage device relative to the initial internal resistance, and A is the mapping coefficient.

[0014] Furthermore, the SOC upper and lower limits are obtained according to the following formula:

[0015] SOC (i)max =SOC (i)max实际 ×α

[0016] SOC (i)min =SOC (i)min实际 ×β

[0017] Among them, SOC(i)max and SOC (i)max are the upper and lower limits of SOC for the i-th energy storage device; SOC (i)max实际 and SOC (i)min实际 are the actual SOC upper limit and SOC lower limit of the i-th energy storage device respectively; α and β are adjustment coefficients, and both α and β are determined according to the current health status of the energy storage device and / or the grid status.

[0018] Furthermore, the reactive deviation ΔQ allocated to the i-th PCS i for:

[0019] ΔQ i =-K pi ×ΔQ α

[0020] ΔQ i =Q i -Q n

[0021]

[0022] Among them, Q i is the reactive power that the i-th PCS needs to output; Q n is the reactive power currently output by the i-th PCS; ΔQ α Reactive power deviation that requires all PCS to adjust; SOC (i) is the current SOC value of the energy storage device corresponding to the i-th PCS; SOC (i)min is the lower limit of SOC of the energy storage device corresponding to the i-th PCS; SOC (i)max is the SOC upper limit value of the energy storage device corresponding to the i-th PCS; n is the number of PCSs involved in the regulation.

[0023] Furthermore, if |Q i |≥γQ ei :When PCS is discharging, let Q i =γQ ei ; When PCS is charging, let Q i =-γQ ei ;

[0024] Among them, Q i is the reactive power that the i-th PCS needs to output; Q ei is the rated reactive power of the i-th PCS; γ is the reactive power limiting coefficient.

[0025] Furthermore, the condition for the i-th PCS to exit reactive power regulation is: when the PCS needs to be charged, SOC (i) ≥SOC (i)max ; or when PCS needs to be discharged, SOC(i) ≤SOC (i)min .

[0026] Furthermore, if the sum of the current SOCs of all PCSs exceeds the sum of the upper SOC limits, the reactive power surplus regulation of the PCSs is blocked, so that the PCSs exit the reactive power regulation when the reactive power deviation is greater than 0;

[0027] If the sum of the current SOCs of all PCSs is lower than the sum of the SOC lower limits, the reactive power deficit regulation of the PCSs is blocked, so that the PCSs exit the reactive power regulation when the reactive power deviation is less than 0.

[0028] Furthermore, the reactive power deviation is obtained in the following manner: real-time monitoring of the grid connection point voltage, and when the grid connection point voltage is not within a preset allowable range, determining the reactive power deviation that needs to be adjusted based on the actual bus voltage and the rated voltage;

[0029] Or receive the control target sent by the master station, and determine the reactive power deviation that needs to be adjusted according to the control target.

[0030] Furthermore, the method of receiving the control target sent by the master station and determining the reactive power deviation to be adjusted according to the control target includes: if the control target sent by the master station is voltage, converting the voltage deviation into a reactive power deviation by a proportional coefficient.

[0031] Furthermore, the grid state includes load fluctuation.

[0032] The present invention also provides a technical solution for a computer system: a computer system comprising a processor, wherein the processor is configured to execute a computer program to implement the steps of the automatic voltage control method based on the EMS as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of voltage stability area division in an embodiment of the automatic voltage control method based on EMS of the present invention;

[0034] Figure 2 This is an AVC control flow chart of an embodiment of an automatic voltage control method based on EMS of the present invention;

[0035] Figure 3 Schematic diagram of PCS reactive power limitation in an embodiment of an automatic voltage control method based on EMS of the present invention. DETAILED DESCRIPTION

[0036] Unlike existing technologies that rely on fixed ideal SOC upper and lower limits for energy storage devices, the present invention dynamically adjusts the SOC upper and lower limits based on the device's health and / or grid load. This extends the life of the energy storage device by preventing aging equipment from being in a high SOC state for extended periods, reducing battery degradation; improving system reliability by dynamically adjusting the output upper limit based on grid conditions to prevent overload risks; and achieving a balance between grid demand and device health, reducing overall operation and maintenance costs. This invention addresses the technical issue of high operation and maintenance costs associated with existing AVC control methods.

[0037] Example of automatic voltage control method based on EMS:

[0038] An automatic voltage control method based on EMS, the method comprising:

[0039] S1. Determine the reactive power deviation that needs to be adjusted;

[0040] S2. Allocate the reactive power deviation to each reactive power regulation device involved in reactive power regulation, so that each reactive power regulation device outputs according to the allocation result; the reactive power regulation device includes a PCS; the reactive power deviation allocated to each PCS is determined based on the current SOC and the upper and lower limits of the SOC of the energy storage device corresponding to the PCS; the upper and lower limits of the SOC are determined based on (1) and / or (2):

[0041] (1) When the energy storage device needs to be charged, the worse the health state of the energy storage device is, the lower the SOC upper limit of the energy storage device is; when the energy storage device needs to be discharged, the worse the health state of the energy storage device is, the higher the SOC lower limit of the energy storage device is;

[0042] (2) When the energy storage device needs to be charged, the worse the grid state is, the higher the SOC upper limit of the energy storage device is; when the energy storage device needs to be discharged, the worse the grid state is, the lower the SOC lower limit of the energy storage device is.

[0043] The EMS-based automatic voltage control method of this embodiment can be applied to an EMS (Energy Management System). It collects grid operation data from the EMS in real time, including bus voltage, generator reactive output, reactive compensation equipment status, load changes, etc. The collected data is then preprocessed, including data cleaning, outlier removal, and data compression, to ensure data accuracy and real-time performance, and dynamically adjust the AVC control strategy. The present invention aims to provide an AVC automatic voltage control method and system based on real-time data analysis and optimization of the EMS system. By monitoring the grid operation status in real time and dynamically adjusting the AVC control parameters, precise grid voltage control is achieved.

[0044] The energy storage AVC control system uses the energy storage power station's bus voltage or reactive power as its control target. It automatically receives voltage / reactive power target commands from the dispatching master station and calculates reactive power changes using safe, reliable, and efficient algorithms. It then achieves the dispatching control target by adjusting reactive power compensation equipment, PCS, transformer taps, and other factors. The AVC program monitors voltage changes at the grid connection point in real time. If the voltage exceeds the system's permitted range, it proactively implements reactive power regulation to ensure the grid connection point voltage remains within the permitted range.

[0045] like Figure 1 As shown in the figure, based on the voltage dynamic characteristics, the voltage stability level is divided into four regions. When the voltage is within Region A, it is within the power quality requirements and the system does not require any additional control. When the voltage is within Region B, the energy storage reactive power can be adjusted to return the system voltage to the qualified zone (Region A). When insufficient or failed reactive compensation causes the voltage to enter the emergency zone (Region C), and the energy storage's regulation capacity is limited, low-voltage load shedding and high-voltage generator shedding are used to restore the system voltage. Region D represents the system collapse zone, where simple output adjustment or load shedding alone cannot restore the system to a stable operating state. Operator intervention is required to manually control the system's black start. Regions B and C are controllable. For the safe operation of the energy storage equipment, excessive charging and discharging of the energy storage is prohibited. The control strategy of this device focuses on Region B and does not consider Region C. When a reactive power deficit or surplus occurs, the reactive power change is distributed among all operating PCSs. The reactive power value allocated to each PCS is determined by the power regulation allocation value.

[0046] like Figure 2 As shown, the present invention supports both remote and local control modes. In remote mode, the high-voltage bus voltage control target value and total reactive power target value issued by the dispatching master station are received, and the reactive power deviation that needs to be adjusted is determined based on the control target issued by the dispatching master station. If the received control target is reactive power, the reactive power deviation ΔQ that needs to be adjusted is determined according to the following formula:

[0047] ΔQ=Q 目标 -Q 当前

[0048] Among them, Q 目标 is the received reactive power control target; Q 当前 is the current reactive power of the energy storage power station.

[0049] If the control target is voltage, the voltage control target is converted into reactive power deviation ΔQ according to the following formula:

[0050] ΔQ=K×ΔU=U 目标 -U 当前

[0051] Among them, K is the proportional coefficient; ΔU is the voltage deviation; U 目标 is the received bus voltage control target; U 当前 is the current reactive power of the energy storage power station.

[0052] In the local control mode, the grid voltage of the energy storage power station is monitored in real time. When the grid voltage is not within the preset allowable range (i.e. Figure 1 The reactive power deviation ΔQ that needs to be adjusted is determined based on the actual bus voltage and rated voltage:

[0053] ΔQ=K u N[U-(U N +ΔU1)]

[0054] Among them, K u is the voltage regulation coefficient, U is the actual line voltage (i.e. bus voltage) of the energy storage power station (when reactive power shortage or surplus occurs, it is a symmetrical fault, so U is taken ab As the calculated voltage), U N is the rated voltage of the energy storage power station, ΔU1 is the allowable voltage deviation, and N is the power coefficient constant.

[0055] When the three line voltages of the power grid all drop and enter the U region B L.m <U≤U L.max In the interval, calculate the reactive power shortage ΔQ, where U L.max =U N -ΔU is the limit value of line voltage under normal operation, U L.m It is the lower limit value of the line voltage in area B.

[0056] When the three line voltages of the power grid rise and enter the U region B H.min ≤U<U H.m During the interval, calculate the reactive power surplus ΔQ. H.min =U N +ΔU is the upper limit of line voltage in normal operation, U H.m It is the upper limit of the line voltage in area B.

[0057] After determining the reactive power deviation ΔQ that requires adjustment, if the adjustment deviation is less than the control deadband, no control is performed. If the adjustment deviation is greater than the control step size, the control step size is selected as the new station-wide adjustment deviation. Adjust the reactive power deviation gradually according to the control step size to avoid equipment damage caused by excessive adjustments at one time.

[0058] Then, the upper and lower adjustment capabilities of each PCS and SVG are calculated based on the operating status, current reactive output, maximum and minimum adjustable reactive power, and adjustment accuracy of the PCS and SVG reactive compensation devices. The reactive power deviation of the entire station is proportionally distributed to each reactive device (including each PCS and each SVG) based on the adjustment capacity.

[0059] When allocating reactive power deviation, it can be set in advance whether to give priority to PCS or SVG, or to allocate them equally without priority.

[0060] Based on the current reactive power output and the allocated regulation deviation, the regulation targets of each PCS and SVG are calculated and the target power is sent to the PCS and SVG devices.

[0061] Among them, for the PCS, the reactive power that each PCS needs to output is determined according to the reactive power currently output by the PCS, the current SOC of the energy storage device corresponding to the PCS, and the upper and lower limits of the SOC.

[0062] Specifically, the reactive deviation ΔQ allocated to the i-th PCS i for:

[0063] ΔQ i =-K pi ×ΔQ α

[0064] ΔQ i =Q i -Q n

[0065]

[0066] Among them, Q i is the reactive power that the i-th PCS needs to output; Q n is the reactive power currently output by the i-th PCS; ΔQ α Reactive power deviation that requires all PCS to adjust; SOC (i) is the current SOC value of the energy storage device corresponding to the i-th PCS; SOC (i)min is the lower limit of SOC of the energy storage device corresponding to the i-th PCS; SOC (i)max is the SOC upper limit value of the energy storage device corresponding to the i-th PCS; n is the number of PCSs involved in the regulation.

[0067] To achieve a balance between grid demand and equipment health, reduce overall operation and maintenance costs, prevent aging equipment from being in a high SOC state for a long time, and reduce battery degradation, the SOC upper and lower limits of the energy storage device corresponding to each PCS in this embodiment change with the health status of the energy storage device and the grid status.

[0068] For the health status, if the grid state remains unchanged: when the energy storage device needs to be charged, the worse the health status of the energy storage device is, the lower the SOC upper limit of the energy storage device is; when the energy storage device needs to be discharged, the worse the health status of the energy storage device is, the higher the SOC lower limit of the energy storage device is.

[0069] For the grid status, if the health status remains unchanged: when the energy storage device needs to be charged, the worse the grid status is, the higher the SOC upper limit of the energy storage device is; when the energy storage device needs to be discharged, the worse the grid status is, the lower the SOC lower limit of the energy storage device is.

[0070] That is to say, the health status and the grid status each affect the changes in the SOC upper and lower limits separately, and the final changes in the SOC upper and lower limits are the superposition of the health status and the grid status when they each affect the SOC upper and lower limits separately.

[0071] In other embodiments, the SOC upper and lower limits may also dynamically change only according to the health status, or only according to the grid status.

[0072] Specifically, in this embodiment, the grid state includes load fluctuation.

[0073] Specifically, the real-time health data of each energy storage device is monitored in real time, and the health status of the energy storage device is evaluated based on the health data. In this embodiment, the health status of the energy storage device is evaluated using a health index, and the energy storage device is classified into different health levels (e.g., good, fair, poor) based on the health index.

[0074] In this embodiment, the health data selected are the cycle number and internal resistance change that have the greatest impact on the health of the energy storage device. The health index H i According to the following formula:

[0075] H i =A / (CC×IR)

[0076] Wherein, CC is the number of cycles of the energy storage device, IR is the change in the current internal resistance of the energy storage device relative to the initial internal resistance (i.e., the internal resistance of the energy storage device when it leaves the factory), and A is the mapping coefficient.

[0077] In this embodiment, H i Mapped to 0-100, take A=1000. In other implementations, A can be set to other values. In this case, H i Will be mapped to other intervals.

[0078] The health index is divided into different levels representing different health status according to the size. Specifically, the division is as follows:

[0079] When H i When ≥80, the health status is good; when 40<H iWhen H is less than 80, the health status is good; i When ≤40, the health status is poor.

[0080] Based on the above data, SOC is dynamically calculated through a preset algorithm. (i)max and SOC (i)min , rather than being fixed to theoretical values 1 and 0. Dynamically adjust SOC according to health status and grid status (i)max and SOC (i)min :

[0081] For devices with a "poor" health status, reduce the SOC of the energy storage device when charging. (i)max ; During discharge, increase the SOC of the energy storage device (i)min , to slow down performance degradation. For devices with a health level of "good", maintain or appropriately increase SOC (i)max , maintain or appropriately increase SOC (i)min .

[0082] During periods of high grid load, the SOC upper limit of the energy storage device is temporarily increased during charging; during discharging, the SOC lower limit of the energy storage device is temporarily lowered to enhance the grid support capacity.

[0083] SOC (i)max =SOC (i)max实际 ×α

[0084] SOC (i)min =SOC (i)min实际 ×β

[0085] Among them, SOC (i)max and SOC (i)max are the upper and lower limits of SOC for the i-th energy storage device; SOC (i)max实际 and SOC (i)min实际 are the actual SOC upper and lower limits of the i-th energy storage device respectively; α and β are adjustment coefficients, which are determined according to the current health status of the energy storage device and / or the grid status. By adjusting α and β, the SOC upper and lower limits of the energy storage device are adjusted to achieve the above-mentioned dynamic adjustment of SOC (i)max and SOC (i)min way.

[0086] When the number of cycles of a certain energy storage device exceeds the threshold, the system automatically (i)max It dropped from 0.9 to 0.8, and was temporarily increased to 0.85 during the evening peak period based on load forecasts to achieve refined control.

[0087] At the same time, if Figure 3 As shown, when making allocations, consider the following conditions to avoid overload: If |Q i|≥γQ ei , then when PCS is discharging, let Q i =γQ ei ; When PCS is charging, let Q i =-γQ ei ;

[0088] Among them, Q i is the reactive power that the i-th PCS needs to output; Q ei is the rated reactive power of the i-th PCS; γ is the reactive power limiting coefficient.

[0089] The reactive power distribution of SVG can be referred to the existing technology, and will not be described in detail in this embodiment.

[0090] After obtaining the reactive power required to be output by each PCS and each SVG participating in reactive power regulation, the command is sent to each PCS and each SVG (i.e. Figure 2 When the difference between the reactive power currently output by the energy storage power station and the target reactive power falls within the allowable error range, the regulation ends.

[0091] The conditions for locking or exiting the adjustment process are as follows:

[0092] The condition for PCS i to exit reactive power regulation is: when PCS needs to be charged, SOC (i) ≥SOC (i)max ; or when PCS needs to be discharged, SOC (i) ≥SOC (i)min .

[0093] AVC will be automatically locked when there are abnormal measurements such as the reactive power of the grid-connected branch, unreasonable high-voltage bus voltage data, unchanged data, frequency and voltage exceeding the locking limit, or custom locking events.

[0094] If the sum of the current SOCs of all PCSs exceeds the sum of the SOC upper limits (ie, the PCS has no reactive power surplus regulation capability), the PCS reactive power surplus regulation is blocked, so that the PCS exits reactive power regulation when the reactive power deviation is greater than 0.

[0095] If the sum of the current SOCs of all PCSs is lower than the sum of the SOC lower limits (i.e., the PCS has no reactive power deficit adjustment capability), the PCS reactive power deficit adjustment is blocked to cause the PCS to exit reactive power adjustment when the reactive power deviation is less than 0.

[0096] The PCS control is locked when abnormalities such as PCS equipment failure and communication interruption occur.

[0097] AVC control for the entire station is terminated when the following conditions occur: 200ms after the measured frequency exits Zone B; 200ms after all PCSs exit power control.

[0098] Computer system embodiment:

[0099] A computer system includes a processor configured to execute a computer program to implement the steps of the EMS-based automatic voltage control method described above. The specific EMS-based automatic voltage control method has been described in sufficient detail in the above-described EMS-based automatic voltage control method embodiment and will not be repeated here.

[0100] Specifically, the processor may be a CPU, or other general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor may also be a processor that supports the Advanced RISC Machine (ARM) architecture.

[0101] The present invention has the following characteristics:

[0102] (1) Improve voltage control accuracy: Through real-time data analysis and adaptive control algorithms, precise control of grid voltage is achieved, the real-time performance and accuracy of AVC control are improved, voltage fluctuations are reduced, and power quality is improved.

[0103] (2) Enhanced response speed: The system can monitor the grid's operating status in real time, has strong adaptability, and can quickly respond to grid changes, adjust control strategies, and ensure stable grid operation. A high degree of automation reduces manual intervention and lowers operation and maintenance costs.

[0104] (3) Improve economic efficiency: By optimizing the switching schedule of reactive power compensation equipment and generator excitation control, grid losses are reduced, energy utilization efficiency is improved, and operating costs are reduced. A high degree of automation reduces manual intervention and reduces operation and maintenance costs.

[0105] (4) Enhance system stability: By comprehensively evaluating the stability of the power grid and predicting the voltage change trend, a more reasonable control strategy can be formulated to improve the anti-interference ability and stability of the power grid.

[0106] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments without inventive effort, or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An automatic voltage control method based on EMS, characterized in that: The method includes: S1. Determine the reactive power deviation that needs to be adjusted; S2. Allocate the reactive power deviation to each reactive power regulation device involved in reactive power regulation, so that each reactive power regulation device outputs according to the allocation result; the reactive power regulation device includes a PCS; the reactive power deviation allocated to each PCS is determined based on the current SOC and the upper and lower limits of the SOC of the energy storage device corresponding to the PCS; the upper and lower limits of the SOC are determined based on (1) and / or (2): (1) When the energy storage device needs to be charged, the worse the health state of the energy storage device is, the lower the SOC upper limit of the energy storage device is; when the energy storage device needs to be discharged, the worse the health state of the energy storage device is, the higher the SOC lower limit of the energy storage device is; (2) When the energy storage device needs to be charged, the worse the grid state is, the higher the SOC upper limit of the energy storage device is; when the energy storage device needs to be discharged, the worse the grid state is, the lower the SOC lower limit of the energy storage device is.

2. The automatic voltage control method based on EMS according to claim 1, characterized in that: The health status is evaluated by the health index: the health index is divided into levels representing different health status according to the size; the health index H i According to the following formula: H i =A / (CC×IR) Wherein, CC is the number of cycles of the energy storage device, IR is the change of the current internal resistance of the energy storage device relative to the initial internal resistance, and A is the mapping coefficient.

3. The automatic voltage control method based on EMS according to claim 1 or 2, characterized in that: The SOC upper and lower limits are obtained according to the following formula: SOCIETY (i)max =SOC (i)max实际 ×α SOCIETY (i)min =SOC (i)min实际 ×β Among them, SOC (i)max and SOC (i)max are the upper and lower limits of SOC for the i-th energy storage device; SOC (i)max实际 and SOC (i)min实际 are the actual SOC upper limit and SOC lower limit of the i-th energy storage device respectively; α and β are adjustment coefficients, and both α and β are determined according to the current health status of the energy storage device and / or the grid status.

4. The automatic voltage control method based on EMS according to claim 1, characterized in that: Reactive power deviation ΔQ allocated to the i-th PCS i for: ΔQ i =-K pi ×ΔQ α ΔQ i =Q i -Q n Among them, Q i is the reactive power that the i-th PCS needs to output; Q n is the reactive power currently output by the i-th PCS; ΔQ α Reactive power deviation that requires all PCS to adjust; SOC (i) is the current SOC value of the energy storage device corresponding to the i-th PCS; SOC (i)min is the lower limit of SOC of the energy storage device corresponding to the i-th PCS; SOC (i)max is the SOC upper limit value of the energy storage device corresponding to the i-th PCS; n is the number of PCSs involved in the regulation.

5. The automatic voltage control method based on EMS according to claim 1 or 4, characterized in that: If|Q i |≥γQ ei :When PCS is discharging, let Q i =γQ ei ; When PCS is charging, let Q i =-γQ ei ; Among them, Q i is the reactive power that the i-th PCS needs to output; Q ei is the rated reactive power of the i-th PCS; γ is the reactive power limiting coefficient.

6. The automatic voltage control method based on EMS according to claim 1, characterized in that: The condition for PCS i to exit reactive power regulation is: when PCS needs to be charged, SOC (i) ≥SOC (i)max ; or when PCS needs to be discharged, SOC (i) ≤SOC (i)min .

7. The automatic voltage control method based on EMS according to claim 1, characterized in that: If the sum of the current SOCs of all PCSs exceeds the sum of the SOC upper limits, the PCS reactive power surplus regulation is blocked, so that the PCS exits the reactive power regulation when the reactive power deviation is greater than 0; If the sum of the current SOCs of all PCSs is lower than the sum of the SOC lower limits, the reactive power deficit regulation of the PCSs is blocked, so that the PCSs exit the reactive power regulation when the reactive power deviation is less than 0.

8. The automatic voltage control method based on EMS according to claim 1, characterized in that: The reactive power deviation is obtained by: monitoring the grid connection point voltage in real time, and when the grid connection point voltage is not within a preset allowable range, determining the reactive power deviation that needs to be adjusted based on the actual bus voltage and the rated voltage; Or receive the control target sent by the master station, and determine the reactive power deviation that needs to be adjusted according to the control target.

9. The automatic voltage control method based on EMS according to claim 8, characterized in that: The method of receiving the control target sent by the master station and determining the reactive power deviation to be adjusted according to the control target includes: if the control target sent by the master station is voltage, converting the voltage deviation into the reactive power deviation through a proportional coefficient.

10. The automatic voltage control method based on EMS according to claim 1, characterized in that: The grid state includes load fluctuation.

11. A computer system comprising a processor, characterized in that: The processor is configured to execute a computer program to implement the steps of the EMS-based automatic voltage control method according to any one of claims 1 to 10.

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