10kV distribution transformer on-load voltage regulation control method and system

Abstract

The invention discloses a 10kV distribution transformer on-load voltage regulation control method and system, and relates to the technical field of transformer on-load voltage regulation, and the method comprises the steps: collecting the three-phase voltage and current of a low-voltage side of a distribution transformer and a tap switch gear signal, and loading a preset voltage regulation control mode and an oscillation region parameter; based on the acquired three-phase voltage and current of the low-voltage side of the distribution transformer and the tap switch gear signal, calculating a feeder comprehensive impedance parameter and a load reactive power parameter, and outputting a transformer operation state index; according to the transformer operation state index, the voltage regulation control mode and the oscillation area rule, current voltage out-of-limit and reactive power deviation are judged, and a voltage regulation strategy triggering instruction is generated according to the judgment result; and calculating upper and lower limit values of feed line correction voltage based on the voltage regulation strategy trigger instruction, and controlling the tap switch to execute voltage regulation action. According to the method, a combined calculation scheme of feeder comprehensive impedance and load reactive power is fused, and dynamic optimization of the triggering condition of the voltage regulation strategy is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transformer on-load voltage regulation, in particular to a 10kV distribution transformer on-load voltage regulation control method and system. BACKGROUND

[0002] The traditional automatic on-load voltage regulation technology is relatively simple, only monitors the transformer outgoing line bus voltage, and when the voltage meets the conditions, the tap changer is operated according to the situation, without considering the influence of system reactive parameter and feeder parameter voltage regulation control.

[0003] When the voltage oversteps due to the excessive load on the secondary side of the transformer and insufficient system reactive compensation, if the tap change is immediately performed to increase the voltage, the voltage may reverse and overstep after the reactive compensation, causing strategy jitter and system oscillation.

[0004] Secondly, when the terminal load center of the distribution transformer is far away, the influence of line voltage drop on user voltage quality needs to be considered, and the voltage value of the load center needs to be corrected to modify the voltage regulation action parameters. SUMMARY

[0005] In view of the above problems, the present application is proposed.

[0006] Therefore, the technical problem solved by the present application is that the existing 10kV distribution transformer automatic voltage regulation method only judges according to the bus voltage, does not consider the influence of feeder voltage drop, has low response capability to reactive fluctuation, is prone to voltage regulation oscillation, and how to realize the coordinated identification of feeder voltage drop and reactive deviation in the process of transformer voltage regulation, and dynamically correct the voltage regulation strategy to realize more stable and reasonable voltage regulation control.

[0007] To solve the above technical problems, the present application provides the following technical scheme: a 10kV distribution transformer on-load voltage regulation control method, comprising collecting the three-phase voltage, current and tap changer position signal of the low-voltage side of the distribution transformer, and loading the preset voltage regulation control mode and oscillation zone parameters.

[0008] Based on the collected three-phase voltage, current and tap changer position signal of the low-voltage side of the distribution transformer, the feeder comprehensive impedance parameter and the load reactive power parameter are calculated, and the transformer operating state index is output.

[0009] According to the transformer operating state index, voltage regulation control mode and oscillation zone rule, the current voltage overstep and reactive deviation are judged, and the voltage regulation strategy trigger instruction is generated according to the judgment result.

[0010] The feeder corrected voltage upper and lower limit values are calculated based on the voltage regulation strategy trigger instruction, and the tap changer is controlled to perform voltage regulation action.

[0011] As a preferred scheme of the 10kV distribution transformer on-load voltage regulation control method, the collection of the distribution transformer low-voltage side three-phase voltage, current and tap switch position signal comprises: using the voltage sensor and current transformer arranged at the low-voltage side outlet of the transformer to collect the instantaneous voltage value and current value of the A, B and C three-phase, and through the analog-to-digital conversion circuit, the analog signal is converted into a digital signal and synchronously transmitted into the controller, and the current position signal of the tap switch is read through the logic circuit, including the position number and action state; the collected data is used as the basis for subsequent calculation of the feeder impedance and reactive power.

[0012] As a preferred scheme of the 10kV distribution transformer on-load voltage regulation control method, the loading of the preset voltage regulation control mode and the oscillation zone parameters comprises: when initializing and receiving the dispatching instruction, the controller reads the local and remote configuration files, loads the control mode, the upper and lower limit parameters of the oscillation zone, the position range, the voltage regulation action interval threshold and the reactive power compensation priority interval setting, and loads the parameters in the controller memory and continuously participates in the running state index and strategy judgment process during the running process.

[0013] As a preferred scheme of the 10kV distribution transformer on-load voltage regulation control method, the calculation of the feeder comprehensive impedance parameter and the load reactive power parameter comprises: the controller calculates the feeder voltage drop and reactive load condition according to the collected three-phase voltage, current data and tap switch position signal, the feeder comprehensive impedance is calculated based on the voltage-current difference function, and the load reactive power is obtained through the voltage-current phase angle calculation method.

[0014] The feeder comprehensive impedance and the load reactive power constitute part of the running state index.

[0015] As a preferred scheme of the 10kV distribution transformer on-load voltage regulation control method, the output of the transformer running state index comprises: the calculated feeder impedance parameter and load reactive power parameter, the collected voltage and current values and the current position state jointly constitute a running state structure.

[0016] The structure comprises: an out-of-limit identification bit, an oscillation zone identification bit, a compensation feasibility identification bit and position movable state information.

[0017] As a preferred scheme of the 10kV distribution transformer on-load voltage regulation control method, the judgment of the current voltage out-of-limit and reactive deviation comprises: the controller compares the voltage value in the running state structure with the preset voltage upper and lower limits, when the out-of-limit identification bit is true, it continues to judge whether it is in the oscillation zone and whether the current reactive power has compensation capacity, and according to the comprehensive judgment logic, the strategy triggering condition is determined.

[0018] As a preferred scheme of the 10kV distribution transformer on-load voltage regulation control method, the generated voltage regulation strategy trigger instruction comprises generating a voltage regulation control instruction containing an action direction, an expected gear, and an action effective time according to the judged out-of-limit condition and the strategy setting, and the instruction content is written into a controller buffer and transmitted downward for power supply voltage correction calculation.

[0019] As a preferred scheme of the 10kV distribution transformer on-load voltage regulation control method, the calculated feeder correction voltage upper and lower limit values comprise that the controller combines the action direction in the voltage regulation strategy instruction with the current feeder impedance parameter and current value, dynamically adjusts the voltage upper and lower limit parameters by using a correction function, and inputs the corrected voltage limit values to the action control logic as voltage regulation execution boundaries.

[0020] As a preferred scheme of the 10kV distribution transformer on-load voltage regulation control method, the control of the tap switch to perform the voltage regulation action comprises that the controller triggers a drive circuit to control the tap switch to adjust the gear in the specified direction according to the voltage regulation instruction and the corrected voltage upper and lower limit values, continuously monitors the gear feedback and the action state during the execution, and re-collects the voltage, current, and gear information after the action is completed to enter a new round of data collection process.

[0021] Another object of the present application is to provide a 10kV distribution transformer on-load voltage regulation control system, which can realize multi-parameter fusion analysis and closed-loop strategy execution by constructing a linkage control structure comprising a parameter acquisition and strategy loading module, a state parameter calculation and index generation module, an operation state analysis and strategy judgment module, and a correction control and execution adjustment module, and solve the problem of response lag and frequent misoperation of the current distribution transformer voltage regulation system caused by the failure to comprehensively consider the feeder voltage drop, load reactive power change, and voltage oscillation interval characteristics.

[0022] As a preferred scheme of the 10kV distribution transformer on-load voltage regulation control system, it comprises

[0023] A computer device comprising a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the 10kV distribution transformer on-load voltage regulation control method.

[0024] A computer readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the steps of the 10kV distribution transformer on-load voltage regulation control method.

[0025] The 10kV distribution transformer on-load voltage regulation control method provided by the application fuses the joint calculation scheme of feeder comprehensive impedance and load reactive power, realizes dynamic optimization of the trigger condition of the voltage regulation strategy, sets the voltage regulation oscillation zone and the correction voltage limit mechanism, effectively avoids frequent false triggering and over-limit voltage regulation problems, and achieves better effects in the accuracy of the voltage regulation strategy, the stability of voltage control, and the response robustness of system operation. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0027] Figure 1 A 10kV distribution transformer on-load voltage regulation control method provided for the embodiment 1 of the application. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned purposes, features and advantages of the application more apparent and easy to understand, the specific embodiments of the application will be described in detail below with reference to the drawings of the specification. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor should be within the protection scope of the application.

[0029] Embodiment 1, refer to Figure 1 For an embodiment of the application, a 10kV distribution transformer on-load voltage regulation control method is provided, which comprises:

[0030] S1: Collecting the three-phase voltage, current and tap switch position signals of the distribution transformer low-voltage side, loading the preset voltage regulation control mode and oscillation zone parameters.

[0031] The voltage sensor and current transformer configured at the low-voltage side outlet of the transformer are used to collect the instantaneous voltage values and current values of A, B and C three phases respectively, the analog signals are converted into digital signals through an analog-to-digital conversion circuit, and then the digital signals are synchronously transmitted into the controller, and the current position signal of the tap switch is read through a logic circuit, including the position number and action state; the collected data is used as the basic input for subsequent calculation of feeder impedance and reactive power.

[0032] As a preferred scheme for the basic input for subsequent calculation of feeder impedance and reactive power:

[0033] voltage_vector=[UA ,U B ,U C ],current_vector=[I A ,I B ,I C ]

[0034] wherein, U A ,U B ,U C represent the three-phase voltage of the distribution transformer low-voltage side A, B, C, I A ,I B ,I C represent the three-phase current of the distribution transformer low-voltage side A, B, C, voltage_vector represents the voltage vector, and current_vector represents the current vector.

[0035] Further, the controller reads the local and remote configuration files when initializing and receiving scheduling instructions, loads the control mode, upper and lower limit parameters of the oscillation zone, gear range, voltage adjustment action interval threshold value, and reactive power compensation priority interval setting, loads the parameters into the memory of the controller, and continuously participates in the running state index and strategy judgment process during operation.

[0036] S2: Based on the collected three-phase voltage, current and tap switch gear position signals of the distribution transformer low-voltage side, the feeder comprehensive impedance parameter and the load reactive power parameter are calculated, and the transformer running state index is output.

[0037] The controller calculates the feeder voltage drop and reactive load according to the collected three-phase voltage, current data and tap switch gear position signals, and combines the transformer operation model. The feeder comprehensive impedance is calculated based on the voltage and current difference function, and the load reactive power is obtained by the voltage and current phase angle calculation method.

[0038] One preferred scheme for calculating the feeder comprehensive impedance and the load reactive power is:

[0039]

[0040] Q=U2·I2·sin(φ)

[0041] wherein, X f represents the feeder comprehensive impedance, U1 represents the equivalent voltage of the distribution transformer high-voltage side, U2 represents the collected voltage of the distribution transformer low-voltage side, I2 represents the collected current of the distribution transformer low-voltage side, Q represents the load reactive power, and φ represents the phase angle between voltage and current.

[0042] The feeder comprehensive impedance and the load reactive power constitute part of the running state index.

[0043] Further, the calculated feeder impedance parameter, the load reactive power parameter, the collected voltage and current values and the current gear state jointly constitute an operation state structure.

[0044] The structure includes an over-limit identification bit, an oscillation zone identification bit, a compensation feasibility identification bit and gear movable state information.

[0045] S3: According to the transformer operation state index, the voltage regulation control mode and the oscillation zone rule, the current voltage over-limit and reactive deviation are judged, and a voltage regulation strategy trigger instruction is generated according to the judgment result.

[0046] The controller compares the voltage value in the operation state structure with the preset upper and lower voltage limits. When the over-limit identification bit is true, it continues to judge whether it is in the oscillation zone and whether the current reactive power has compensation capability. According to the comprehensive judgment logic, the strategy trigger condition is determined.

[0047] One preferred scheme for calculating the corrected upper and lower voltage limits is:

[0048] U' max = U max +k·I2·X f

[0049] U' min = U min +k·I2·X f

[0050] Wherein, U max represents the original set upper voltage limit, U min represents the original set lower voltage limit, U' max represents the corrected upper voltage limit, U' min represents the corrected lower voltage limit, and k represents the feeder voltage drop correction coefficient.

[0051] One preferred scheme for judging whether voltage over-limit occurs is:

[0052] (U2>U' max ) or (U2<U' min )

[0053] Further, according to the over-limit condition and the strategy setting, a voltage regulation control instruction containing the action direction, the expected gear, and the action effective time is generated. The instruction content is written into the controller buffer and is passed down for voltage correction calculation.

[0054] S4: Calculate the feeder corrected upper and lower voltage limits based on the voltage regulation strategy trigger instruction, and control the tap switch to perform voltage regulation action.

[0055] The controller combines the action direction in the voltage regulation strategy instruction with the current feeder impedance parameter and current value, dynamically adjusts the upper and lower voltage limit parameters by using a correction function, and inputs the corrected voltage limit value to the action control logic as a voltage regulation execution boundary.

[0056] Further, the controller triggers the driving circuit to control the tapping switch to adjust the gear according to the specified direction according to the voltage regulation instruction and the corrected upper and lower voltage limit values, continuously monitors the gear feedback and action state during the execution, re-collects the voltage, current and gear information after the action is completed, and enters a new round of data collection process.

[0057] A preferred scheme for triggering the driving circuit to control the tapping switch to adjust the gear according to the specified direction is:

[0058] TAP new = TAP current + ΔTAP

[0059] Wherein, TAP new represents the generated target gear number, TAP current represents the current tapping switch gear, and ΔTAP represents the target gear change amount.

[0060] After the gear is changed, the corresponding output voltage is estimated according to the target gear.

[0061] A preferred scheme for estimating the corresponding output voltage is:

[0062]

[0063] Wherein, represents the estimated low-voltage side output voltage after the target gear acts, U base represents the reference voltage, TAP0 represents the reference gear number, and ΔU step represents the voltage change value per gear.

[0064] Embodiment 2 is an embodiment of the present application, which provides a 10kV distribution transformer on-load voltage regulation control system, including a parameter acquisition and strategy loading module, a state parameter calculation and index generation module, a running state analysis and strategy judgment module, and a correction control and execution adjustment module.

[0065] Wherein, the parameter acquisition and strategy loading module is used to acquire the distribution transformer low-voltage side three-phase voltage, current and tapping switch gear signal, and load the preset voltage regulation control mode and oscillation zone parameters.

[0066] The state parameter calculation and index generation module is used to calculate the feeder comprehensive impedance parameter and load reactive power parameter based on the acquired distribution transformer low-voltage side three-phase voltage, current and tapping switch gear signal, and output the transformer running state index.

[0067] The running state analysis and strategy judgment module is configured to judge the current voltage out-of-limit and reactive power deviation according to the transformer running state index, the voltage regulation control mode and the oscillation region rule, and generate a voltage regulation strategy trigger instruction according to the judgment result.

[0068] The correction control and execution adjustment module is configured to calculate the upper and lower limit values of the feeder correction voltage based on the voltage regulation strategy trigger instruction, and control the tap changer to perform the voltage regulation action.

Claims

1. A method for on-load tap changer control of a 10kV distribution transformer, characterized in that, include: Collect the three-phase voltage, current and tap changer position signals of the low-voltage side of the distribution transformer, and load the preset voltage regulation control mode and oscillation zone parameters; Based on the collected three-phase voltage, current and tap changer position signals of the low-voltage side of the distribution transformer, the comprehensive impedance parameters of the feeder and the reactive power parameters of the load are calculated, and the transformer operating status indicators are output. Based on the transformer operating status indicators, voltage regulation control mode, and oscillation zone rules, determine the current voltage over-limit and reactive power deviation, and generate voltage regulation strategy trigger commands based on the judgment results; The upper and lower limits of the feeder correction voltage are calculated based on the voltage regulation strategy trigger command, and the tap changer is controlled to perform voltage regulation.

2. The on-load tap changer control method for a 10kV distribution transformer as described in claim 1, characterized in that: The acquisition of three-phase voltage, current, and tap changer position signals on the low-voltage side of the distribution transformer includes... The instantaneous voltage and current values ​​of phases A, B, and C are collected by voltage sensors and current transformers configured on the low-voltage side of the transformer. The analog signals are converted into digital signals by analog-to-digital converter circuits and then synchronously transmitted to the controller. The controller is combined with logic circuits to read the current tap position signal of the tap changer, including the tap position number and operating status. The collected data serves as the basis for subsequent calculation of feeder impedance and reactive power.

3. The on-load tap changer control method for a 10kV distribution transformer as described in claim 2, characterized in that: The preset voltage regulation control mode and oscillation zone parameters include, When the controller initializes and receives scheduling instructions, it reads local and remote configuration files, loads control mode, upper and lower limit parameters of oscillation zone, gear range, voltage regulation action interval threshold and reactive power compensation priority range settings, caches the loaded parameters in the controller memory, and continuously participates in the operation status indicators and strategy judgment process during operation.

4. The on-load tap changer control method for a 10kV distribution transformer as described in claim 3, characterized in that: The calculated feeder impedance parameters and load reactive power parameters include... The controller calculates the feeder voltage drop and reactive load based on the collected three-phase voltage and current data and tap changer position signals, combined with the transformer operation model. The feeder comprehensive impedance is calculated based on the voltage-current difference function, and the load reactive power is obtained by calculating the voltage-current phase angle. The feeder impedance and load reactive power constitute part of the operating status indicators.

5. The on-load tap changer control method for a 10kV distribution transformer as described in claim 4, characterized in that: The operating status indicators of the output transformer include, The calculated feeder impedance parameters, load reactive power parameters, collected voltage and current values, and current tap status are combined to form the operating status structure. The structure includes over-limit indicator, oscillation zone indicator, compensation feasibility indicator, and gear position movable status information.

6. The on-load tap changer control method for a 10kV distribution transformer as described in claim 5, characterized in that: The determination of current voltage exceeding limits and reactive power deviation includes, The controller compares the voltage value in the operating status structure with the preset upper and lower voltage limits. When the over-limit flag is true, it continues to determine whether it is in the oscillation zone and whether the current reactive power has compensation capability. Based on the comprehensive judgment logic, it determines the strategy triggering conditions.

7. The on-load tap changer control method for a 10kV distribution transformer as described in claim 6, characterized in that: The generated voltage regulation strategy trigger instruction includes: Based on the determined over-limit situation and strategy settings, a voltage regulation control command is generated, which includes the action direction, expected gear, and effective action time. The command content is written into the controller buffer and passed down to the supply voltage correction calculation.

8. The on-load tap changer control method for a 10kV distribution transformer as described in claim 7, characterized in that: The calculation of the upper and lower limits of the feeder correction voltage includes: The controller combines the action direction in the voltage regulation strategy instruction with the current feeder impedance parameters and current value, and uses a correction function to dynamically adjust the upper and lower voltage limit parameters. The corrected voltage limit is used as the voltage regulation execution boundary input to the action control logic.

9. The on-load tap changer control method for a 10kV distribution transformer as described in claim 8, characterized in that: The control tap changer performs voltage regulation actions including... The controller triggers the drive circuit to control the tap changer to adjust the gear in the specified direction according to the voltage adjustment command and the corrected upper and lower voltage limits. During the execution, the gear feedback and action status are continuously monitored. After the action is completed, the voltage, current and gear information are collected again, and a new round of data acquisition process begins.

10. A 10kV distribution transformer on-load tap-changing control system, employing the 10kV distribution transformer on-load tap-changing control method as described in any one of claims 1 to 9, characterized in that: It includes a parameter acquisition and strategy loading module, a status parameter calculation and index generation module, an operation status analysis and strategy judgment module, and a correction control and execution adjustment module; The parameter acquisition and strategy loading module is used to acquire the three-phase voltage, current and tap changer position signals of the low-voltage side of the distribution transformer, and load the preset voltage regulation control mode and oscillation zone parameters. The state parameter calculation and index generation module is used to calculate the feeder comprehensive impedance parameters and load reactive power parameters based on the collected three-phase voltage, current and tap changer position signals on the low-voltage side of the distribution transformer, and output the transformer operating status index. The operation status analysis and strategy judgment module is used to judge the current voltage over-limit and reactive power deviation based on the transformer operation status indicators, voltage regulation control mode and oscillation zone rules, and generate voltage regulation strategy triggering instructions based on the judgment results; The correction control and execution adjustment module is used to calculate the upper and lower limits of the feeder correction voltage based on the voltage regulation strategy trigger command, and control the tap changer to perform voltage regulation action.

11. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the on-load tap changer control method for a 10kV distribution transformer as described in any one of claims 1 to 9.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the on-load tap changer control method for a 10kV distribution transformer as described in any one of claims 1 to 9.

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