A line area voltage management method

Abstract

The application discloses a line area voltage management method, and relates to the technical field of electric power, which has the following steps: collecting grid-connected point line voltage, comparing the grid-connected point line voltage with a control reference voltage to obtain a voltage deviation result; triggering a corresponding management condition in a preset working interval according to the voltage deviation result; when the management condition is triggered, adjusting reactive power to obtain a first adjustment result, and if the first adjustment result meets a preset switching condition, superimposedly adjusting active power to obtain a second adjustment result; when the management condition is not triggered, performing power charging and discharging adjustment according to a power backfall result to calibrate a state of charge; wherein, the power charging and discharging adjustment process dynamically calculates an adjustment amount in combination with the voltage deviation result and a preset adjustment coefficient, and the management process and the state of charge calibration process are mutually interrupted and switched, so that the electric quantity safety control is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of power technology, and more specifically, to a method for controlling line-area voltage. Background Technology

[0002] When distributed photovoltaic (PV) power generation equipment is connected to a distribution network, the excess active power on the lines during peak daytime PV output can easily cause voltage spikes at the grid connection point. Conversely, a significant power shortage during peak evening residential electricity demand can lead to voltage drops. This results in drastic voltage fluctuations throughout the day, consistently deviating from the standard operating range and directly threatening the operational safety of distribution and end-user equipment. Existing energy storage voltage regulation solutions mostly rely on high-power charging and discharging of energy storage batteries to adjust active power and offset voltage deviations, without prioritizing reactive and active power regulation, thus exhibiting multiple practical shortcomings.

[0003] Current technologies rely entirely on active power for voltage regulation. During frequent high-power charging and discharging, energy storage devices experience approximately 15% energy loss in regulation, continuously increasing the overall operating losses of power distribution lines and reducing the energy utilization efficiency of the distribution area. Simultaneously, frequent high-power charging and discharging accelerates the aging of energy storage cells, shortening the overall battery lifespan.

[0004] Traditional voltage regulation control logic lacks a tiered fallback mechanism. When the line voltage returns to its standard value, it directly cuts off all active and reactive power output. Sudden power fluctuations cause secondary voltage oscillations, making it impossible to maintain a stable voltage transition. Existing solutions do not differentiate the execution priority between voltage management and battery charge calibration processes. When a sudden voltage shift occurs during battery equalization charging and discharging operations, the calibration process cannot be quickly interrupted to prioritize voltage regulation, potentially exacerbating power supply risks caused by voltage anomalies. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for controlling line voltage.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for controlling line voltage includes the following steps:

[0008] Collect the grid connection point line voltage and compare it with the control reference voltage to obtain the voltage deviation result;

[0009] Based on the voltage deviation results, trigger the corresponding governance conditions within the preset working range;

[0010] When the governance condition is triggered, the reactive power is adjusted to obtain the first adjustment result. If the first adjustment result meets the preset switching condition, the active power is adjusted to obtain the second adjustment result. Based on the second adjustment result, a power constraint verification is performed, and the power is reduced according to priority when the voltage recovers to obtain the power drop result.

[0011] When the governance conditions are not triggered, power charging and discharging regulation is performed to calibrate the state of charge based on the power drop results; wherein, the power charging and discharging regulation process dynamically calculates the regulation amount by combining the voltage deviation results with the preset regulation coefficient, and the governance process and the state of charge calibration process are interrupted and switched to each other.

[0012] Preferably, the corresponding treatment conditions are triggered within a preset working range based on the voltage deviation results, specifically including the following steps:

[0013] The first and second governance initiation criteria are derived based on the voltage deviation results.

[0014] When the voltage deviation result indicates that the line voltage at the grid connection point is lower than the first governance start criterion, a low-voltage governance trigger signal is generated;

[0015] When the voltage deviation result indicates that the line voltage at the grid connection point is higher than the second governance start criterion, a high-voltage governance trigger signal is generated;

[0016] The low-voltage treatment trigger signal and the high-voltage treatment trigger signal serve as the triggering basis for power regulation.

[0017] Preferably, when the governance conditions are triggered, the reactive power is adjusted to obtain the first adjustment result, specifically including the following steps:

[0018] In response to the low-voltage governance trigger signal, the converter is controlled to output capacitive reactive power or discharge to obtain the first reactive power regulation result;

[0019] In response to the high-voltage regulation trigger signal, the converter is controlled to output inductive reactive power or charge to obtain a second reactive power regulation result;

[0020] When the first reactive power adjustment result or the second reactive power adjustment result reaches the reactive power limit, a reactive power limit signal is generated as the preset switching condition.

[0021] The first reactive power regulation result is a combination of the first reactive power regulation result and the second reactive power regulation result.

[0022] Preferably, the second adjustment result is obtained by superimposing the adjusted active power, specifically including the following steps:

[0023] In response to the reactive power limit signal, the active power regulation formula is called to calculate the active power regulation amount;

[0024] The active power regulation formula is as follows: ;

[0025] in, For active power regulation, The active power regulation coefficient, The active speed regulation coefficient and is related to Related, To adjust the time steps, The line voltage at the grid connection point. To control the reference voltage;

[0026] The second adjustment result is obtained by superimposing the active power adjustment amount onto the current power.

[0027] Preferably, the power constraint verification is performed based on the second adjustment result, specifically including the following steps:

[0028] Extract the current reactive power setpoint from the second adjustment result. ;

[0029] Based on the device's rated apparent power The calculated upper limit of active power regulation satisfies the constraint relationship. ;

[0030] If the active power of the second adjustment result exceeds the active power adjustment upper limit, then the second adjustment result is limited and corrected to generate a verified target power result.

[0031] Preferably, the power is reduced according to priority during voltage recovery to obtain a power drop-off result, specifically including the following steps:

[0032] When the grid connection point line voltage returns to the control reference voltage, the active power component of the reduced target power result yields the intermediate result of active power reduction.

[0033] The power reduction result is obtained by reducing the reactive power component based on the intermediate results of active power reduction.

[0034] Preferably, power charge / discharge regulation is performed based on the power drop-off result to calibrate the state of charge, specifically including the following steps:

[0035] When the power retracement result indicates that the battery is in standby mode, if the battery state of charge is higher than the preset upper limit threshold, a low-power discharge command is assigned based on the power retracement result until the state of charge falls back to the upper limit retracement threshold.

[0036] If the battery state of charge is lower than the preset lower threshold, a low-power charging command is assigned based on the power drop result until the state of charge recovers to the lower hysteresis threshold.

[0037] The execution priority of the low-power discharge command and the low-power charging command is lower than that of the governance trigger signal.

[0038] Preferably, when the grid connection point line voltage returns to the control reference voltage, the active power component of the reduced target power result is used to obtain the intermediate result of active power reduction, specifically including the following steps:

[0039] When the grid connection point line voltage returns to the control reference voltage, the active power component of the target power result is gradually reduced, the reactive power component of the target power result is maintained, and the output volume of active power is reduced, thus obtaining the active power reduction condition.

[0040] Generate intermediate results for active power fall-off based on active power fall-off conditions.

[0041] Preferably, generating intermediate results for active power slump based on the active power slump condition specifically includes the following steps:

[0042] Collect the actual active power operation data of the equipment under active power fallback conditions, and perform steady-state verification processing on the active power fallback conditions;

[0043] Based on the active power decline condition processed by steady-state verification, power operation information is integrated;

[0044] Intermediate results for active power reduction are generated based on power operation information.

[0045] Preferably, the power reduction result is obtained by reducing the reactive power component based on the intermediate result of active power reduction, specifically including the following steps:

[0046] The current active power output state is locked based on the intermediate results of active power reduction, and the reactive power component is subjected to step-by-step reduction control.

[0047] Once the reactive power component has fallen back to a stable state, the stable reactive power condition and the intermediate active power decline result are fused to obtain the power decline result.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] This invention corrects line voltage based on reactive power, only adding active power to the regulation when reactive power regulation reaches its output limit. This significantly reduces the frequency and duration of active charging and discharging in the energy storage system. Reducing active power regulation directly lowers overall line power loss, improves the operational efficiency of distribution lines, and avoids the ineffective dissipation of a large amount of electricity during energy storage charging and discharging. The reactive power-priority regulation mode can reduce the capacity configuration of the DC-side batteries in the energy storage system. Line voltage fluctuations are caused by reactive power imbalance due to line inductive reactance. The reactive power regulation capability of the converter resolves most of the voltage deviation problem, significantly shortening the working time of high-power charging and discharging of the battery, slowing down the cell cycle decay rate, and extending the overall service life of the entire energy storage system. A layered and orderly power fallback logic is set up. When the voltage recovers, active power is released and fallback is gradually reduced first, and then reactive power is reduced step by step. This avoids secondary voltage oscillations caused by sudden power changes, ensuring that the grid connection point voltage smoothly returns to the standard range and ensuring safe power management. Attached Figure Description

[0050] Figure 1 This is a flowchart illustrating a method for controlling line voltage according to an embodiment of the present invention;

[0051] Figure 2 This is a schematic flowchart illustrating the process of obtaining power reduction results in a line voltage control method according to an embodiment of the present invention.

[0052] Figure 3 This is a schematic diagram of the adjustment strategy in a line voltage management method provided in an embodiment of the present invention. Detailed Implementation

[0053] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0054] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0055] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0056] Reference Figures 1-3 As shown.

[0057] The embodiments further illustrate the line voltage control method proposed in this invention.

[0058] A method for controlling line voltage includes the following steps:

[0059] Collect the grid connection point line voltage and compare it with the control reference voltage to obtain the voltage deviation result;

[0060] The system obtains the current actual operating voltage value of the line, controls the reference voltage as the standard voltage value for safe and stable line operation, compares the line voltage at the grid connection point with the control reference voltage, and calculates the voltage deviation result by taking the difference between the two sets of voltage values. The voltage deviation result can distinguish whether the line is currently operating in a state of excessively high or low voltage.

[0061] Based on the voltage deviation results, trigger the corresponding governance conditions within the preset working range;

[0062] When the governance conditions are triggered, the reactive power is adjusted to obtain the first adjustment result. If the first adjustment result meets the preset switching conditions, the active power is adjusted to obtain the second adjustment result. Based on the second adjustment result, a power constraint verification is performed, and the power is reduced according to priority when the voltage recovers to obtain the power drop result.

[0063] When the governance conditions are not triggered, power charging and discharging regulation is performed based on the power drop results to calibrate the state of charge. The power charging and discharging regulation process dynamically calculates the regulation amount by combining the voltage deviation results with the preset regulation coefficient, and the governance process and the state of charge calibration process are interrupted and switched to each other.

[0064] Based on the voltage deviation results, the corresponding governance conditions are triggered within the preset operating range, specifically including the following steps:

[0065] The first and second governance initiation criteria are derived based on the voltage deviation results.

[0066] When the voltage deviation result indicates that the line voltage at the grid connection point is lower than the first governance start criterion, a low-voltage governance trigger signal is generated;

[0067] When the voltage deviation result indicates that the line voltage at the grid connection point is higher than the second governance start criterion, a high-voltage governance trigger signal is generated;

[0068] The low-voltage regulation trigger signal and the high-voltage regulation trigger signal serve as the triggering basis for power regulation.

[0069] Based on the voltage deviation results, two sets of governance initiation criteria are generated for voltage threshold determination. These two sets of criteria correspond to the upper and lower boundary values ​​of the line's normal operating range. The first governance initiation criterion corresponds to the lowest safe voltage limit allowed for line operation, and the second governance initiation criterion corresponds to the highest safe voltage limit allowed for line operation. For example, the standard reference voltage for a typical rural distribution line is 10kV. Based on the voltage deviation results, the first governance initiation criterion is calculated to be 9kV, and the second governance initiation criterion is 10.5kV. The range of 9kV to 10.5kV is the preset operating range where the line does not require governance initiation.

[0070] Low-voltage governance start-up threshold , This is the low-pressure treatment activation coefficient. The default value is 3%, which means the minimum line voltage is 9.4kV; To control the reference voltage, This is the rated voltage at the grid connection point.

[0071] When the real-time line voltage value is lower than the voltage value corresponding to the first regulation initiation criterion, it indicates that the current operating condition of the line has deviated from the preset operating range, belonging to a low-voltage abnormal condition caused by overload, thus generating a continuous and effective low-voltage regulation trigger signal. In the evening, residents' concentrated use of high-power appliances causes a surge in line load, and the real-time line voltage drops to 8.8kV. Since this is lower than the first regulation initiation criterion, a low-voltage regulation trigger signal is generated, preparing to initiate a power regulation operation to raise the voltage.

[0072] High-pressure governance start threshold , This is the high-pressure treatment start-up coefficient. The default value is 4.8%, which means the maximum line voltage is 10.48kV.

[0073] When the real-time line voltage exceeds the voltage value corresponding to the second regulation initiation criterion, it indicates that the photovoltaic power generation output of the line is excessive, and the voltage operation value exceeds the upper limit of the preset operating range, thus generating a high-voltage regulation trigger signal. At noon, when distributed photovoltaic power is at full capacity, the real-time line voltage rises to 10.6kV. Since this is higher than the second regulation initiation criterion, a high-voltage regulation trigger signal is generated, preparing to execute the regulation action of reducing the line voltage.

[0074] The low-voltage governance trigger signal and the high-voltage governance trigger signal are transmitted to the power regulation control unit. The power regulation control unit will not actively start the reactive or active power regulation operation. Only when it receives any kind of valid trigger signal will it start the corresponding voltage governance power regulation process. When the line voltage drops back to the preset operating range of 9kV to 10.5kV, the two types of trigger signals will automatically fail, stop all voltage governance-related power output, and switch to the steady-state operation mode of battery state of charge calibration.

[0075] When the governance conditions are triggered, the reactive power is adjusted to obtain the first adjustment result, which specifically includes the following steps:

[0076] In response to the low-voltage governance trigger signal, the converter outputs capacitive reactive power or discharges to obtain the first reactive power regulation result;

[0077] In response to the high-voltage regulation trigger signal, the converter outputs inductive reactive power or charging to obtain the second reactive power regulation result;

[0078] When the first or second reactive power regulation result reaches the reactive power limit, a reactive power limit signal is generated as a preset switching condition.

[0079] In this embodiment, before collecting the line voltage at the grid connection point and performing hierarchical reactive / active voltage regulation, the equivalent impedance of the feeder is first calculated. , Solve and / ratio Calculation, based on Dynamic constraints It has active and reactive power regulation limits to achieve impedance-matched power distribution without affecting normal power supply quality.

[0080] Basic model of feeder voltage drop: ;

[0081] The current is decomposed into active and reactive components, and injected into the grid connection point in two small-amplitude step disturbances:

[0082] Step 1: Only a small reactive power disturbance is introduced. Simultaneously collect the voltage change at the grid connection point before and after the disturbance. Current change ;

[0083] Step 2: Only a small active power disturbance is introduced. Simultaneously collect the voltage change at the grid connection point before and after the disturbance. Current change ;

[0084] By simultaneously solving the voltage and current equations for the two disturbances, the equivalent resistance of the feeder can be directly solved analytically. Equivalent reactance Calculate the impedance ratio ;

[0085] Classic voltage drop formula for distribution networks: ;

[0086] Will Substituting into the voltage drop formula and simplifying, we get: ;

[0087] In the formula , With fixed parameters, the line voltage regulation effect is solely determined by... Based on this decision, two types of line operating conditions are distinguished:

[0088] High-resistance lines >1: Active power It has a stronger voltage regulation effect;

[0089] High sensitivity circuit <1: Reactive power It plays a dominant role in voltage regulation;

[0090] Under the rated apparent power constraint of the equipment, increase the upper limit of the regulation of the power component with high voltage regulation contribution, reduce the upper limit of the inefficient component, and make full use of the PCS capacity.

[0091] A set of equations is constructed based on the apparent power capacity constraints of the combined equipment and the voltage regulation and equalization distribution conditions:

[0092] ;

[0093] Will Substituting into the capacity constraint derivation: The final universal power limit calculation formula is as follows: ;

[0094] In the formula: The rated apparent power of the energy storage converter; To adaptively adjust the upper limit of active power; This is the upper limit for adaptive reactive power adjustment.

[0095] In the second adjustment result power constraint verification stage, the power calculated by this formula will be used. It replaces the original fixed active power limit to complete the amplitude correction, and realizes dynamic adjustment of the power output boundary according to the line impedance characteristics.

[0096] The first reactive power regulation result is the combination of the first reactive power regulation result and the second reactive power regulation result.

[0097] If a low-voltage regulation trigger signal is detected, it indicates that the total load of the current distribution line exceeds its carrying capacity, resulting in a low line voltage. A control command is then issued to drive the energy storage converter to output capacitive reactive power. This capacitive reactive power can offset the voltage drop caused by the line's inductive impedance, thereby raising the operating voltage at the grid connection point. If capacitive reactive power alone cannot bring the voltage back to the standard range, the converter simultaneously releases active power to assist in voltage boosting. The power operation data generated by reactive power combined with discharge in low-voltage scenarios is recorded as the first reactive power regulation result. For example, if the voltage of a 10kV standard distribution line drops to 9.4kV during the peak load period at night, the equipment executes the regulation logic to output capacitive reactive power, simultaneously generating the corresponding first reactive power regulation result through discharge.

[0098] When a high-voltage regulation trigger signal is detected, it indicates that the distributed photovoltaic output on the line is excessive and the line voltage exceeds the safety limit. A command is then issued to control the energy storage converter to output inductive reactive power to reduce the line voltage. If the inductive reactive power adjustment is insufficient to smooth the voltage deviation, the converter simultaneously starts active charging to absorb the excess energy on the line. The operating data resulting from the combination of reactive power and charging under high-voltage conditions is recorded as the second reactive power regulation result. During the midday peak photovoltaic power generation period, when the line voltage rises to 10.48kV, exceeding the 10.4kV safety limit, the equipment outputs inductive reactive power in conjunction with the charging operation, thus generating the corresponding second reactive power regulation result.

[0099] The reactive power output values ​​within the first and second reactive power adjustment results are collected in real time. The energy storage converter itself has a fixed reactive power output limit value, which is determined by the rated apparent power parameter of the equipment. When the reactive power output volume of any type of reactive power adjustment result reaches the preset reactive power upper limit value of the equipment, it means that there is no adjustment space to correct the voltage deviation by relying solely on reactive power, thereby generating a reactive power limit signal. The reactive power limit signal is a preset switching condition for starting the superimposed active power adjustment process. No active power level control operation will be initiated if this signal is not detected.

[0100] The first reactive power regulation result records all reactive power control operating parameters under low-voltage abnormal conditions, and the second reactive power regulation result records all reactive power control operating parameters under high-voltage abnormal conditions, covering the complete reactive power regulation operating conditions of all voltage deviation scenarios of the line. The two types of results are integrated and summarized to form the first regulation result. The first regulation result is used as the output data of the reactive power regulation stage to determine whether to switch to the active power superposition regulation process.

[0101] The second adjustment result is obtained by superimposing the adjusted active power, specifically including the following steps:

[0102] In response to the reactive power limit signal, the active power regulation formula is called to calculate the active power regulation amount;

[0103] The active power regulation formula is: ;

[0104] in, For active power regulation, The active power regulation coefficient, The active speed regulation coefficient and is related to Related, To adjust the time steps, The line voltage at the grid connection point. To control the reference voltage;

[0105] The second regulation result is obtained by superimposing the active power regulation amount onto the current power.

[0106] This represents the active power regulation. The positive or negative value distinguishes whether the energy storage device is discharging or charging. A positive value means that the device needs to release active power to raise the line voltage, while a negative value means that the device needs to absorb active power from the line to lower the line voltage. The active power regulation coefficient plays a weighting role in proportional regulation, determining the active power output amplitude corresponding to the static voltage deviation. For example, when the distribution line impedance is too high, it will... Set to 0.8. Variable This is the active power speed regulation coefficient, used to suppress frequent sudden changes in active power caused by rapid voltage fluctuations, for example, When the value is 0.8, the corresponding settings are as follows: The value is 0.02, used to balance response speed and operational stability. (Variable) This represents the adjustment time step, which corresponds to the fixed duration of a single cycle operation of the control system. Conventional energy storage control equipment sets this step to 0.01 seconds to ensure timely response of power adjustment. The line voltage at the grid connection point, acquired in real time, is continuously refreshed and transmitted by the voltage acquisition module. To control the reference voltage.

[0107] Taking a 10kV base line as an example, at a certain moment The measured value is 9.4 kV. The value is 0.8. The value is 0.02. Set to 0.01 seconds, substitute into the formula and calculate. It was determined that energy storage discharge needed to supplement line power and boost voltage. This was necessary if the photovoltaic system was operating at full capacity at midday. The collected value is 10.48 kV. After substituting it into the formula for calculation... If the output is negative, it indicates that the excess active power of the energy storage charging absorption circuit needs to be controlled.

[0108] Extract the reactive power operating condition data of the current equipment, superimpose the active power adjustment into the current reactive power operating condition, and integrate the reactive power component with the newly added active power component to form a power operating condition that includes active and reactive power parameters.

[0109] Based on the second adjustment result, a power constraint verification is performed, which specifically includes the following steps:

[0110] Extract the current reactive power setpoint from the second adjustment result. ;

[0111] Based on the device's rated apparent power The calculated upper limit of active power regulation satisfies the constraint relationship. ;

[0112] If the active power of the second adjustment result exceeds the active power adjustment upper limit, then the second adjustment result is limited and corrected to generate the target power result after verification.

[0113] Retrieve the reactive power operating parameters and define this set of parameters as the current reactive power setpoint. This value represents the amount of reactive power that the equipment can stably output under the current operating conditions, and is the input data for calculating the active power limit.

[0114] ;

[0115] This is the change in reactive power, measured in kVar; the minimum value is not less than... ;

[0116] Line voltage at the telemetry point of the grid connection point of the monitoring and control device, in kV;

[0117] This is the reactive power regulation coefficient;

[0118] Rated power, unit: kW;

[0119] Rated voltage at the grid connection point, in kV;

[0120] The rated apparent power is fixed and unchanging according to the equipment's factory specifications. The apparent power is processed as a vector sum of active and reactive power. From this, the upper limit of active power regulation allowed by the equipment under the current reactive power condition is derived. Taking an energy storage converter with a rated apparent power of 1000 kVA as an example... The value is fixed at 1000, when When the extracted value is 400, the upper limit of active power adjustment corresponding to the current operating condition is about 916, which means that the maximum active power output of the equipment under this reactive power output state is 916 kilowatts.

[0121] The active power value is compared with the active power regulation limit. When the active power value exceeds the active power regulation limit, it means that the total apparent power after adding active and reactive power exceeds the rated capacity of the equipment. Long-term operation will cause the converter to overload and overheat, or even damage the components. In this case, a limiting correction operation is initiated to forcibly constrain the active power value to the active power regulation limit and the reactive power setpoint. Keeping the original values ​​unchanged, the power operating condition is obtained after the correction is completed. This operating condition is the target power result after verification.

[0122] During voltage recovery, power is reduced according to priority to achieve power reduction, which specifically includes the following steps:

[0123] When the grid connection point line voltage returns to the control reference voltage, the active power component of the reduced target power result yields the intermediate result of active power reduction.

[0124] The power reduction result is obtained by reducing the reactive power component based on the intermediate results of active power reduction.

[0125] Using the intermediate result of active power reduction as the basic operating condition, the system locks in the current stable active power output state, maintaining the active power output value unchanged throughout the process. It then performs segmented, step-by-step reduction control on the reactive power component within the operating condition. This step-by-step reduction means that the reactive power is not reduced to zero all at once, but rather divided into multiple small-amplitude reduction intervals to gradually reduce the reactive power output. After each reduction operation, the line voltage fluctuation is continuously monitored. The next reactive power reduction operation is only executed after confirming that the voltage remains stable without deviation. For example, if the equipment currently maintains a stable active power output of 200 kW and a reactive power output of 400 kVar, four reduction intervals are divided, with each interval reducing the reactive power by 100 kVar at a time. After each reduction, five control steps are performed to observe the line voltage. The next reactive power reduction is only executed after confirming that the voltage is stable, preventing the 400 kVar of reactive power from being reduced to zero all at once.

[0126] Continuously implement reactive power reduction control at each level, verifying the line voltage operating status after each reduction, until the reactive power component returns to a stable and unfluctuated operating condition. At this point, the reactive power has been reduced to a reasonable value suitable for the standard voltage range of the line, without causing additional disturbance to the line voltage. The reactive power operating condition and the intermediate results of active power reduction are then fused, integrating all operating parameters of both active and reactive power components. After fusion, the final power reduction result is obtained.

[0127] The voltage range for power retention at low voltage is: , This is the low-pressure hysteresis coefficient.

[0128] The voltage range for power maintenance under high voltage is: ; This is the high-pressure hysteresis coefficient.

[0129] Based on the power drop-off results, power charge-discharge regulation is performed to calibrate the state of charge, specifically including the following steps:

[0130] When the power retracement result indicates that the battery is in standby mode, if the battery state of charge is higher than the preset upper limit threshold, a low-power discharge command is assigned based on the power retracement result until the state of charge falls back to the upper limit retracement threshold.

[0131] If the battery state of charge is lower than the preset lower threshold, a low-power charging command is assigned based on the power drop result until the state of charge recovers to the lower hysteresis threshold.

[0132] The execution priority of low-power discharge commands and low-power charging commands is lower than that of governance trigger signals.

[0133] The power drop result determines whether the device is currently in standby mode. Standby mode indicates that the line voltage at the grid connection point has returned to the preset safe operating range, and the device does not need to continuously output calibration power. At this time, the state of charge (SCC) calibration judgment logic is initiated. The current SCC value of the energy storage battery is collected in real time and compared with the preset upper limit threshold. For example, the preset upper limit threshold is set to 90, and the upper limit hysteresis threshold is set to 85. When the real-time SCC value of the battery is higher than 90, it means that the battery is fully charged. Maintaining a high charge for a long time will accelerate the aging and degradation of the battery cells. According to the power drop result corresponding to the current standby condition, a small power discharge command with a fixed amplitude is allocated. The power value of the small power is lower than the high power adjustment value required for voltage management. For example, only 50 kilowatts of continuous discharge power is allocated. The device continuously performs small power discharge operation and refreshes the SCC value without interruption until the SCC drops to the upper limit hysteresis threshold of 85. At this time, the discharge command is immediately canceled and the release of electrical energy is stopped.

[0134] The system compares the real-time state of charge (SOC) with a preset lower threshold. For example, if the preset lower threshold is set to 20 and the lower hysteresis threshold is set to 25, when the SOC detection value is below 20, it indicates insufficient power reserve. This means that in the event of a sudden low-voltage fault, there will be insufficient power to support voltage boosting. Based on the power drop, a small-amplitude charging command is assigned, for example, using a constant low-power 50 kW to absorb grid power as supplementary power. The equipment continuously performs charging actions and monitors changes in SOC until the value rises back to the lower hysteresis threshold of 25. At this point, the charging command is canceled, and the power calibration operation ends. This avoids frequent start-stop charging and discharging near a single boundary value, reducing frequent inverter operation losses.

[0135] The execution priority of low-power discharge and low-power charging commands is lower than that of low-voltage and high-voltage governance trigger signals. This means that if a voltage deviation occurs in the line during the calibration charge / discharge process, any type of governance trigger signal will be generated, immediately interrupting the currently executing low-power charge / discharge calibration process and prioritizing the switch to the voltage governance power regulation process. For example, if the equipment is performing a 50 kW low-power discharge calibration, and the photovoltaic output suddenly increases at noon, causing the line voltage to rise to 10.48 kV, a high-voltage governance trigger signal will be generated, immediately terminating the discharge calibration and initiating a voltage reduction governance process that combines inductive reactive power with active power charging. Once the line voltage returns to stability and the governance trigger signal fails, the calibration operation for the battery state of charge will resume.

[0136] When the grid connection point line voltage returns to the control reference voltage, the active power component of the reduced target power result yields the intermediate result of active power reduction, which specifically includes the following steps:

[0137] When the grid connection point line voltage returns to the control reference voltage, the active power component of the target power result is gradually reduced, the reactive power component of the target power result is maintained, and the output volume of active power is reduced, thus obtaining the active power reduction condition.

[0138] Generating intermediate results for active power fallback based on the active power fallback condition includes the following steps:

[0139] Collect the actual active power operation data of the equipment under active power fallback conditions, and perform steady-state verification processing on the active power fallback conditions;

[0140] Based on the active power decline condition processed by steady-state verification, power operation information is integrated;

[0141] Intermediate results for active power reduction are generated based on power operation information.

[0142] The system continuously monitors the real-time line voltage at the grid connection point, compares it with the preset control reference voltage, and calculates the result. When the real-time line voltage stably returns to the value corresponding to the control reference voltage, it indicates that the line voltage deviation problem has been eliminated, and an active power reduction operation is initiated based on the target power result. This reduction means that the entire active power output is not cut off at once, but rather the active power output is gradually reduced in multiple small-amplitude steps. Throughout the process, the reactive power component within the target power result remains unchanged, relying on continuous reactive power output to stabilize the line voltage while only gradually reducing the active power. For example, if there is a low voltage deviation in a 10kV base distribution line, the target power result after equipment verification is 300 kW of active power and 200 kvar of reactive power. When the line voltage stabilizes back to the 10kV base value, the 300 kW of active power will not be directly reduced to zero. Instead, it will be divided into 6 reduction levels. After each reduction level is completed, 10 control steps will be maintained to observe the voltage status. The reactive power will always be stably output at 200 kvar, and the active power volume will be gradually reduced to form the corresponding active power reduction condition.

[0143] After generating the active power reduction condition, the secondary processing flow begins. Based on the current active power reduction condition, intermediate results are generated, and operational data acquisition and steady-state verification are performed. Real-time active power operation data transmitted from the equipment under the active power reduction condition is collected, including the current active power output value, power change rate, and line voltage fluctuation amplitude. Steady-state verification is then performed on the entire active power reduction condition, continuously monitoring power and voltage fluctuation amplitudes over a fixed period to determine whether the current stepped active power reduction condition remains stable without sudden changes. Abnormal data caused by instantaneous fluctuations are eliminated to ensure the condition data has stable and reliable operational reference value. For example, active power operation data after each 50 kW reduction is collected, and the line voltage fluctuation amplitude is continuously observed within 10 control steps. If the fluctuation amplitude is less than 0.2 kV, the current active power reduction condition is considered to have passed the steady-state verification.

[0144] Using the active power decline condition that has completed steady-state verification as the benchmark, the stable active power output parameters, constant reactive power output parameters, real-time line voltage data, and power regulation duration parameters stored within the condition are all collected and integrated to form a power operation information set.

[0145] The power operation information is uniformly and standardizedly stored as an intermediate result of active power reduction. The intermediate result of active power reduction records all stable operating condition data during the active power slow-release reduction phase.

[0146] Read all filtered and integrated power operation information, standardize and classify all internal power parameters, voltage parameters, and adjustment duration parameters for storage, uniformly define data storage format and data reading index, completely encapsulate the active power operation status of the entire stable decline phase, and finally generate the active power decline intermediate result.

[0147] The power reduction result is obtained by reducing the reactive power component based on the intermediate result of active power reduction, which specifically includes the following steps:

[0148] The current active power output state is locked based on the intermediate results of active power reduction, and the reactive power component is subjected to step-by-step reduction control.

[0149] Once the reactive power component has fallen back to a stable state, the stable reactive power condition and the intermediate active power decline result are fused to obtain the power decline result.

[0150] Using the stable active power output value recorded in the intermediate results of active power reduction as a fixed benchmark, the current active power output state is locked throughout the entire process. The output volume of active power is not modified during the entire reactive power control phase; only the reactive power component within the operating condition is subjected to step-by-step reduction control. Step-by-step reduction means that the reactive power value is not directly reduced to zero all at once, but rather the reactive power output is gradually reduced in multiple small-amplitude steps. After each reduction step is completed, the line voltage operating status is continuously monitored for a fixed period of time. The next reactive power reduction operation is only executed after confirming that the voltage has not deviated or oscillated. For example, if the active power output of the equipment currently maintains a stable output of 100 kW and the reactive power output is currently 300 kV, three reactive power reduction levels are defined. The reactive power is reduced by 100 kV in a single step. After each reduction step is completed, the line voltage is continuously monitored for five control steps, maintaining a stable 100 kW active power throughout the entire process while gradually reducing reactive power.

[0151] The reactive power gradually decreases and controls the operation continuously, collecting real-time data on line voltage and reactive power output without interruption, until the reactive power component gradually decreases to a stable and unfluctuated operating condition. At this point, the reactive power output has been adjusted to a reasonable value that will not cause additional disturbance to the line voltage. The reactive power level reduction action is stopped, and the reactive power operating parameters with fluctuation amplitude conforming to the standard are recorded, thus forming a stable reactive power operating condition.

[0152] After obtaining stable reactive power conditions, the operating condition fusion calculation operation is initiated. All operating parameters of the reactive power conditions are fully integrated with the active power operating parameters in the intermediate results of active power reduction. Simultaneously, all supporting information such as real-time line voltage, power regulation duration, and equipment operating status is collected. After the fusion and summary are completed, a standardized power reduction result is generated.

[0153] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0154] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling line-area voltage, characterized in that, Includes the following steps: Collect the grid connection point line voltage and compare it with the control reference voltage to obtain the voltage deviation result; Based on the voltage deviation results, trigger the corresponding governance conditions within the preset working range; When the governance condition is triggered, the reactive power is adjusted to obtain the first adjustment result. If the first adjustment result meets the preset switching condition, the active power is adjusted to obtain the second adjustment result. Based on the second adjustment result, a power constraint verification is performed, and the power is reduced according to priority when the voltage recovers to obtain the power drop result; When the governance conditions are not triggered, power charging and discharging regulation is performed to calibrate the state of charge based on the power drop results; wherein, the power charging and discharging regulation process dynamically calculates the regulation amount by combining the voltage deviation results with the preset regulation coefficient, and the governance process and the state of charge calibration process are interrupted and switched to each other.

2. The method for controlling line voltage according to claim 1, characterized in that, Based on the voltage deviation results, the corresponding governance conditions are triggered within the preset operating range, specifically including the following steps: The first and second governance initiation criteria are derived based on the voltage deviation results. When the voltage deviation result indicates that the line voltage at the grid connection point is lower than the first governance start criterion, a low-voltage governance trigger signal is generated; When the voltage deviation result indicates that the line voltage at the grid connection point is higher than the second governance start criterion, a high-voltage governance trigger signal is generated; The low-voltage treatment trigger signal and the high-voltage treatment trigger signal serve as the triggering basis for power regulation.

3. The method for controlling line voltage according to claim 2, characterized in that, When the governance conditions are triggered, the reactive power is adjusted to obtain the first adjustment result, which specifically includes the following steps: In response to the low-voltage governance trigger signal, the converter is controlled to output capacitive reactive power or discharge to obtain the first reactive power regulation result; In response to the high-voltage regulation trigger signal, the converter is controlled to output inductive reactive power or charge to obtain a second reactive power regulation result; When the first reactive power adjustment result or the second reactive power adjustment result reaches the reactive power limit, a reactive power limit signal is generated as the preset switching condition. The first reactive power regulation result is a combination of the first reactive power regulation result and the second reactive power regulation result.

4. The method for controlling line voltage according to claim 3, characterized in that, The second adjustment result is obtained by superimposing the adjusted active power, specifically including the following steps: In response to the reactive power limit signal, the active power regulation formula is called to calculate the active power regulation amount; The active power regulation formula is as follows: ; in, For active power regulation, The active power regulation coefficient, The active speed regulation coefficient and is related to Related, To adjust the time steps, The line voltage at the grid connection point. To control the reference voltage; The second adjustment result is obtained by superimposing the active power adjustment amount onto the current power.

5. The method for controlling line voltage according to claim 4, characterized in that, Based on the second adjustment result, a power constraint verification is performed, which specifically includes the following steps: Extract the current reactive power setpoint from the second adjustment result. ; Based on the device's rated apparent power The calculated upper limit of active power regulation satisfies the constraint relationship. ; If the active power of the second adjustment result exceeds the active power adjustment upper limit, then the second adjustment result is limited and corrected to generate a verified target power result.

6. The method for controlling line voltage according to claim 5, characterized in that, During voltage recovery, power is reduced according to priority to achieve power reduction, which specifically includes the following steps: When the grid connection point line voltage returns to the control reference voltage, the active power component of the reduced target power result yields the intermediate result of active power reduction. The power reduction result is obtained by reducing the reactive power component based on the intermediate results of active power reduction.

7. The method for controlling line voltage according to claim 6, characterized in that, Based on the power drop-off results, power charge-discharge regulation is performed to calibrate the state of charge, specifically including the following steps: When the power retracement result indicates that the battery is in standby mode, if the battery state of charge is higher than the preset upper limit threshold, a low-power discharge command is assigned based on the power retracement result until the state of charge falls back to the upper limit retracement threshold. If the battery state of charge is lower than the preset lower threshold, a low-power charging command is assigned based on the power drop result until the state of charge recovers to the lower hysteresis threshold. The execution priority of the low-power discharge command and the low-power charging command is lower than that of the governance trigger signal.

8. A method for controlling line voltage according to claim 6, characterized in that, When the grid connection point line voltage returns to the control reference voltage, the active power component of the reduced target power result yields the intermediate result of active power reduction, which specifically includes the following steps: When the grid connection point line voltage returns to the control reference voltage, the active power component of the target power result is gradually reduced, the reactive power component of the target power result is maintained, and the output volume of active power is reduced, thus obtaining the active power reduction condition. Generate intermediate results for active power fall-off based on active power fall-off conditions.

9. A method for controlling line voltage according to claim 8, characterized in that, Generating intermediate results for active power fallback based on the active power fallback condition includes the following steps: Collect the actual active power operation data of the equipment under active power fallback conditions, and perform steady-state verification processing on the active power fallback conditions; Based on the active power decline condition processed by steady-state verification, power operation information is integrated; Intermediate results for active power reduction are generated based on power operation information.

10. A method for controlling line voltage according to claim 9, characterized in that, The power reduction result is obtained by reducing the reactive power component based on the intermediate result of active power reduction, which specifically includes the following steps: The current active power output state is locked based on the intermediate results of active power reduction, and the reactive power component is subjected to step-by-step reduction control. Once the reactive power component has fallen back to a stable state, the stable reactive power condition and the intermediate active power decline result are fused to obtain the power decline result.

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