Angle positioning method of motor control device of power electronic tap switch

Abstract

The invention discloses an angle positioning method of a motor control device of a power electronic tap switch, which belongs to the technical field of electric power and comprises the steps of initialization and parameter generation, gear shifting instruction analysis, motor driving, real-time angle matching, staged braking and gear shifting completion. The technical problem of improving the dynamic response speed and the positioning precision of transformer on-load tap-changer motor control is solved, efficient and reliable braking can be achieved, the response speed is remarkably increased, the service life is remarkably prolonged, the angle correction and gear matching algorithm is utilized, mechanical accumulative errors are eliminated, the positioning precision is improved, the anti-interference capability is improved, and the application range is wide. Completeness of control signals is guaranteed, traditional energy consumption braking is replaced with the short-circuit braking technology, a braking resistor is effectively prevented from being overheated and burnt, and braking reliability and safety are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of electric power, and in particular relates to an angle positioning method for a motor control device of a power electronic tap changer. Background Art

[0002] Currently, voltage regulation of transformer on-load tap-changers mainly relies on the following two traditional technologies: Relay-contactor drive system: A mechanical relay group is used to control the forward and reverse rotation of the DC motor, and the gear position is detected by a physical limit switch (such as a micro switch or travel switch). The gear position signal is transmitted to the controller via hard wiring.

[0003] Basic electronic braking solution: An external energy-consuming braking resistor is used to stop the motor, and a potentiometer or incremental encoder is generally used for angle detection.

[0004] The existing technology has the following obvious deficiencies: Poor dynamic response performance: Mechanical relay contacts typically operate for ≥100ms, with total switching times exceeding 1 second, resulting in significant voltage regulation delays. In one particular model, switching through 12 gears took as long as 15 seconds. Furthermore, the relay contacts' lifespan due to arc erosion is less than 100,000 cycles, and frequent replacement increases maintenance costs.

[0005] Inadequate positioning accuracy: Mechanical limit switches have a large assembly tolerance (±0.5mm), resulting in an angular error exceeding 1.5°. Backlash in the gear transmission system leads to cumulative errors, resulting in deviations as high as 2.4° after 12 gear shifts, seriously impacting output voltage stability. For example, at a 35kV substation, voltage fluctuations of up to ±5% were caused by gear shifting.

[0006] Weak anti-interference capability: Potentiometer signals are transmitted in analog form, and electromagnetic interference can cause readings to jump by more than 10% within a distance of 10 meters. Incremental encoders require re-homing after power outages, and sudden power outages can cause gear position information to be lost.

[0007] Low braking reliability: Traditional energy-consuming brake resistors continuously heat up, exceeding 80°C, accelerating circuit aging. Statistics from one wind farm show that 23% of brake failures are caused by resistor burnout, posing a safety hazard. Summary of the Invention

[0008] The object of the present invention is to provide an angle positioning method for a motor control device of a power electronic tap changer, which solves the technical problem of improving the dynamic response speed and positioning accuracy of the transformer on-load tap changer motor control.

[0009] To achieve the above object, the present invention adopts the following technical solutions: A method for angular positioning of a motor control device of a power electronic tap changer comprises the following steps: Step 1: After the motor control device is powered on, the MCU completes the peripheral initialization and reads the original message value A of the angle sensor. raw And get the adjusted angle value A according to the sensor direction flag angleclockwiseadd adj ; Calculate the maximum value of the circumference A max , zero point offset δ, and then calculate the theoretical interval θ of each gear according to the preset gear algorithm, and generate the gear angle threshold tables for upshifting and downshifting, namely the upshift table and the downshift table; Step 2: The MCU continuously detects the gear adjustment command from the local human-machine interface or the host computer, parses the target gear position Dt, compares the difference ΔD between the target gear position Dt and the current gear position Dc, and determines the running direction and the number of gear steps to move; Step 3: Based on the running direction, the MCU controls the corresponding MOSFET tubes in the H-bridge circuit to turn on, and at the same time, the MCU outputs a PWM drive signal to make the H-bridge circuit drive the motor to rotate in the target direction; Step 4: During the motor operation, the MCU periodically collects A raw , perform original angle conversion, calculate zero point offset δ, perform practical angle conversion, and obtain the final angle A final MCU determines whether to use the upshift table or downshift table for matching, and then searches the matching interval according to the corresponding gear angle threshold table to update the current gear position Dc; Step 5: When the proximity sensor or the gear threshold matching table confirms that the motor shaft has reached the target gear position Dt, the MCU performs the following actions in a staged braking sequence: Gear position a: cut off PWM drive; B gear position: turns on the MOSFET tube of the same arm to perform low-resistance energy-consuming braking; Step 6: After the MCU verifies that Dc=Dt, it stops outputting the PWM signal, saves the final gear position and operation record, and enters standby mode, waiting for the next gear adjustment instruction.

[0010] Preferably, the motor control device includes a MUC, a 485 communication chip, a GPIO interface and a PWM interface; The 485 communication chip, GPIO interface and PWM interface are all connected to the MCU; The 485 communication chip is connected to the angle sensor and communicates with it. The PWM interface is connected to the H-bridge circuit to provide a PWM drive signal to the H-bridge circuit, which drives the motor of the tap changer. The GPIO interface is connected to a proximity sensor, which is used to detect the position of the tap changer and obtain the current gear position reached by the motor shaft.

[0011] Preferably, when executing step 2, the MCU continuously detects the gear shifting instruction from the local human-machine interface or the host computer, and the gear shifting instruction includes the target gear position Dt.

[0012] Preferably, when executing step 1, the following steps are specifically included: Step 1-1: MCU power-on initialization, including initialization of the communication status of the 485 communication chip, the status of the GPIO interface, and the status of the PWM interface; Step 1-2: Read the original angle data collected by the angle sensor and save it as A raw ; Step 1-3: Calculate the adjustment value A adj , the specific method is as follows: If angleclockwiseadd = true, then A adj =A raw On the contrary, A adj =A max -A raw ; Among them, A adj is the angle value after adjustment, A raw is the original message angle value, A max is the maximum value of the circumference, A max =360×R, R=100; Step 1-4: Calculate the zero point offset δ. The specific calculation method is as follows: If AH>AL, then V=A max -(AH-AL); If (AH+V / 2)<A max , then δ=A max -(AH+V / 2)+AL; conversely, δ=AL-(V / 2-(A max -AH)); If AH≤AL, then V=AL-AH, δ=AL-(AH-V / 2); Among them, δ is the zero point offset, V represents an intermediate variable, AH is the angle value of the high gear, and AL is the angle value of the low gear; Steps 1-5: Calculate the practical angle value A final , the specific method is as follows: If AH>AL, then A final =A adj -AL-δ; If A adj ∈[AL-5R,A max ], then A final =A adj -AL+δ; On the contrary, A final=A max -AL+A adj +δ; Step 1-6: Calculate the theoretical angle θ for each gear and generate a gear angle table. The specific method is as follows: Calculate the theoretical angle θ: If AH>AL, then θ=(AH-AL) / (N-1); On the contrary, θ=(A max -AH-AL) / (N-1); Where θ is the theoretical angle of each gear, and N represents the total number of gears; Calculate the gear angle threshold table, specifically calculate the angle threshold range Ti of gear i, and obtain the upshift table, downshift table and standard table: Standard table: Ti = δ + i × θ ± θ × k; Upshift table: Ti = f (Au) + (i-1) × θ up ±θ up ×k up ; Downshift table: Ti=δ+i×θ down ±θ down ×k down ; Where Au is the second gear angle when shifting up, θ down is the downshift angle per gear, θ up is the angle of each gear when upshifting, Ad is the angle of the second-to-last gear when downshifting, f(·) is the angle conversion function, k up =k down =10 / 33.0, k=16.499 / 33.0.

[0013] Preferably, when executing step 2, the specific steps are as follows: Step 2-1: The MCU continuously detects the gear adjustment command from the local human-machine interface or the host computer, and obtains the target gear position Dt after parsing; Step 2-2: The MCU compares the target gear position Dt with the target gear position Dc, calculates the gear position difference ΔD, and determines the target direction of motor rotation and the number of gear positions required to be crossed based on the difference ΔD.

[0014] Preferably, when executing step 4, the following steps are specifically included: Step 4-1: The MCU periodically collects the raw angle data of the angle sensor and performs standardization conversion and zero point correction; Step 4-2: Determine whether the standard angle value crosses zero degrees. If so, select the appropriate conversion method for correction; Step 4-3: Based on the corrected angle value, match the corresponding gear range in the upshift table or downshift table, and update the current gear information in real time. The specific gear matching method is as follows: If M dir =ascend, then θ={i|A final ∈[T （i，low） , T （i，high） ] in up-table}; On the contrary, θ={i|A final ∈[T （i，low） , T （i，high） ] in down-table}.

[0015] Preferably, when executing step 5, the following steps are specifically included: Step 5-1: MCU continuously detects the output signal of the proximity sensor; Step 5-2: When the proximity sensor detects that the motor shaft is close to the mechanical positioning point of the target gear, the MCU first cuts off the PWM drive signal and enters the low-speed control stage, that is, stage b; In the low-speed control stage, the MCU controls the diagonal MOSFETs of the H-bridge to conduct, achieving low-resistance energy-dissipating braking, allowing the motor to decelerate smoothly when approaching the target position; Step 5-3: When the proximity sensor signal confirms that the motor has entered the precise position range, the MCU closes the brake channel and prepares to enter the stop state, which is stage a.

[0016] The angle positioning method of the motor control device of a power electronic tap changer described in the present invention solves the technical problem of improving the dynamic response speed and positioning accuracy of the transformer on-load tap changer motor control. The present invention can achieve efficient and reliable braking, overcome the voltage regulation delay and control inaccuracy problems caused by traditional electromechanical coupling and insufficient signal integrity, adopt MOSFET power tubes to replace mechanical relays, significantly improve the response speed and service life, utilize angle correction and gear matching algorithms to eliminate mechanical cumulative errors and improve positioning accuracy, adopt RS-485 digital communication bus to replace analog signal transmission, improve anti-interference ability, ensure the integrity of control signals, adopt short-circuit braking technology to replace traditional energy consumption braking, effectively avoid overheating and burning of braking resistors, and improve braking reliability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the main flow chart of the present invention; Figure 2 It is the short-circuit braking timing logic diagram of the present invention; Figure 3 is a flow chart of angle conversion of the present invention; Figure 4 is a matching flow chart of the upshift table and the downshift table of the present invention; Figure 5 It is a schematic block diagram of the motor control device of the present invention. DETAILED DESCRIPTION

[0018] Depend on Figure 1-Figure 5 The angle positioning method of the motor control device of the power electronic tap changer shown includes the following steps: Step 1: After the motor control device is powered on, the MCU completes the peripheral initialization and reads the original message value A of the angle sensor. raw And get the adjusted angle value A according to the sensor direction flag angleclockwiseadd adj ; Calculate the maximum value of the circumference A max , zero point offset δ, and then calculate the theoretical interval θ of each gear according to the preset gear algorithm, and generate the gear angle threshold tables for upshifting and downshifting, namely the upshift table and the downshift table; When executing step 1, the specific steps include: Step 1-1: MCU power-on initialization, including initialization of the communication status of the 485 communication chip, the status of the GPIO interface, and the status of the PWM interface; Step 1-2: Read the original angle data collected by the angle sensor and save it as A raw ; Step 1-3: Calculate the adjustment value A adj , the specific method is as follows: If angleclockwiseadd = true, then A adj =A raw On the contrary, A adj =A max -A raw ; Among them, A adj is the angle value after adjustment, A raw is the original message angle value, A max is the maximum value of the circumference, A max =360×R, R=100; Step 1-4: Calculate the zero point offset δ. The specific calculation method is as follows: If AH>AL, then V=A max -(AH-AL); If (AH+V / 2)<A max , then δ=A max -(AH+V / 2)+AL; conversely, δ=AL-(V / 2-(A max -AH)); If AH≤AL, then V=AL-AH, δ=AL-(AH-V / 2); Among them, δ is the zero point offset, V represents an intermediate variable, AH is the angle value of the high gear, and AL is the angle value of the low gear; Steps 1-5: Calculate the practical angle value A final , the specific method is as follows: If AH>AL, then A final =A adj -AL-δ; If A adj ∈[AL-5R,A max ], then A final =A adj -AL+δ; On the contrary, A final =A max -AL+A adj +δ; Step 1-6: Calculate the theoretical angle θ for each gear and generate a gear angle table. The specific method is as follows: Calculate the theoretical angle θ: If AH>AL, then θ=(AH-AL) / (N-1); On the contrary, θ=(A max -AH-AL) / (N-1); Where θ is the theoretical angle of each gear, and N represents the total number of gears; Calculate the gear angle threshold table, specifically calculate the angle threshold range Ti of gear i, and obtain the upshift table, downshift table and standard table: Standard table: Ti = δ + i × θ ± θ × k; Upshift table: Ti = f (Au) + (i-1) × θ up ±θ up ×k up ; Downshift table: Ti=δ+i×θ down ±θ down ×k down ; Where Au is the second gear angle when shifting up, θ down is the downshift angle per gear, θ up is the angle of each gear when upshifting, Ad is the angle of the second-to-last gear when downshifting, f(·) is the angle conversion function, k up =k down =10 / 33.0, k=16.499 / 33.0.

[0019] Step 2: The MCU continuously detects the gear adjustment command from the local human-machine interface or the host computer, parses the target gear position Dt, compares the difference ΔD between the target gear position Dt and the current gear position Dc, and determines the running direction and the number of gear steps to move; In this embodiment, the human-machine interface is provided by a touch screen, which is connected to the MCU; the MCU also communicates with the host computer through a UART interface; The MCU continuously detects the gear adjustment instructions from the local human-machine interface or the host computer, and the gear adjustment instructions include the target gear position Dt.

[0020] When executing step 2, the specific steps are as follows: Step 2-1: The MCU continuously detects the gear adjustment command from the local human-machine interface or the host computer, and obtains the target gear position Dt after parsing; Step 2-2: The MCU compares the target gear position Dt with the target gear position Dc, calculates the gear position difference ΔD, and determines the target direction of motor rotation and the number of gear positions required to be crossed based on the difference ΔD.

[0021] Step 3: Based on the running direction, the MCU controls the corresponding MOSFET tubes in the H-bridge circuit to turn on, and at the same time, the MCU outputs a PWM drive signal to make the H-bridge circuit drive the motor to rotate in the target direction; In this embodiment, the H-bridge circuit includes four MOSFET tubes, namely Q1, Q2, Q3, and Q4. When the forward gear is switched, the MOSFET power tubes Q1 on the upper left and Q3 on the lower right of the H-bridge are turned on, so that the 24V DC voltage is positively loaded to the motor; When the gear needs to be reversed, the MOSFET power tubes of the upper right Q2 and lower left Q4 of the H-bridge are turned on, so that the 24V DC voltage is reversely loaded to the motor; The response time of reversing action is ≤500 milliseconds.

[0022] The H-bridge circuit is a prior art and will not be described in detail.

[0023] Step 4: During the motor operation, the MCU periodically collects A raw , perform original angle conversion, calculate zero point offset δ, perform practical angle conversion, and obtain the final angle A final MCU determines whether to use the upshift table or downshift table for matching, and then searches the matching interval according to the corresponding gear angle threshold table to update the current gear position Dc; When executing step 4, the specific steps include: Step 4-1: The MCU periodically collects the raw angle data of the angle sensor and performs standardization conversion and zero point correction; Step 4-2: Determine whether the standard angle value crosses zero degrees. If so, select the appropriate conversion method for correction; Step 4-3: Based on the corrected angle value, match the corresponding gear range in the upshift table or downshift table, and update the current gear information in real time. The specific gear matching method is as follows: If M dir =ascend, then θ={i|A final ∈[T （i，low） , T （i，high）] in up-table}; otherwise, θ={i|A final ∈[T （i，low） , T （i，high） ] in down-table}.

[0024] ascend means upshift, up-table is the upshift table, down-table is the downshift table; i is the gear number; T （i，low） , T （i，high） They represent the lower and upper angle thresholds for gear position i respectively.

[0025] In this embodiment, if the running direction = upshift: then the current gear i = the index that satisfies A_final∈[threshold interval of the i-th gear in the upshift table]; If the running direction = downshift: then the current gear i = the index that satisfies A_final∈[the threshold interval of the i-th gear in the downshift table].

[0026] Upshift table: stores the upshift angle interval for each gear i [T （i，low） , T （i，high） ] in up-table.

[0027] Downshift table: stores the downshift angle interval for each gear i [T （i，low） , T （i，high） ] in down-table.

[0028] Step 5: When the proximity sensor or the gear threshold matching table confirms that the motor shaft has reached the target gear position Dt, the MCU performs the following actions in a staged braking sequence: Gear position a: cut off PWM drive; B gear position: turns on the MOSFET tube of the same arm to perform low-resistance energy-consuming braking; When executing step 5, the specific steps include: Step 5-1: MCU continuously detects the output signal of the proximity sensor; Step 5-2: When the proximity sensor detects that the motor shaft is close to the mechanical positioning point of the target gear, the MCU first cuts off the PWM drive signal and enters the low-speed control stage, that is, stage b; In the low-speed control stage, the MCU controls the diagonal MOSFETs of the H-bridge to conduct, achieving low-resistance energy-dissipating braking, allowing the motor to decelerate smoothly when approaching the target position; Step 5-3: When the proximity sensor signal confirms that the motor has entered the precise position range, the MCU closes the brake channel and prepares to enter the stop state, which is stage a.

[0029] Step 6: After the MCU verifies that Dc=Dt, it stops outputting the PWM signal, saves the final gear position and operation record, and enters standby mode, waiting for the next gear adjustment instruction.

[0030] The motor control device includes MUC, 485 communication chip, GPIO interface and PWM interface; The 485 communication chip, GPIO interface and PWM interface are all connected to the MCU; The 485 communication chip is connected to the angle sensor and communicates with it. The PWM interface is connected to the H-bridge circuit to provide a PWM drive signal to the H-bridge circuit, which drives the motor of the tap changer. The GPIO interface is connected to a proximity sensor, which is used to detect the position of the tap changer and obtain the current gear position reached by the motor shaft.

[0031] In this embodiment, the motor drive circuit utilizes IRF3205 MOSFET power transistors to build an H-bridge drive circuit, and the driver chip is the HIP4081. The power circuit utilizes 2oz copper foil with a minimum trace width of 3mm, capable of carrying a maximum current of 25A. To ensure drive signal quality, the gate drive cable length is kept to within 5cm, and twisted-pair shielded cable is used for interference resistance.

[0032] High braking response performance is required, requiring a response time of less than 10 milliseconds from the triggering of the brake signal to full short circuit, and a coil current decay time of no more than 50 milliseconds from 12A to 0A. The mechanical part must have high positioning accuracy, with the rotor offset angle after braking less than 0.1 degrees.

[0033] Gear position signal detection uses a chip-type proximity sensor (Hall sensor DN8799) installed at any 360-degree position on the tap changer's rotary dial to accurately capture the gear position signal. The angle sensor uses the high-precision TLE5012B chip, achieving a resolution of 0.1 degrees. The angle sensor's signal is initially processed by a low-power STM32L151 microcontroller before being converted to an RS-485 digital signal for transmission via a MAX485 chip, ensuring interference resistance over long distances. The angle sensor must be installed coaxially with the switch's rotation axis to ensure accurate angle measurement.

[0034] This embodiment uses an STM32F407 microprocessor to execute the gear control algorithm. Upon system startup, the switch mechanical position is set to 1st gear and the current gear position is recorded. A pre-calculated table of upshift and downshift angle thresholds is used to quickly locate and match the current gear position. Based on user-input gear shift commands, the motor drive circuit is controlled to ensure smooth and precise gear shifting of the tap changer.

[0035] The essence of this technology lies in replacing mechanical relays with fully electronic MOSFET power tubes, eliminating mechanical contacts and achieving nanosecond switching speeds (the IRF3205 has a turn-on delay of only 35 nanoseconds). Combined with PWM soft-start and braking algorithms, this effectively eliminates the inrush current during motor start-stop, reducing peak current from 40A to 25A and ensuring control response delays of less than 10ms.

[0036] The single-gear positioning error is ±0.05°, which is 97% lower than that of the traditional relay solution. Taking the 12th gear as an example, the cumulative error of the 12th gear is less than 0.1°, which is 96% lower than that of the traditional relay solution. The forward and reverse gear meshing error is less than 0.1°, which is 97% lower than that of the traditional relay solution.

[0037] This invention achieves extreme industrial-grade positioning accuracy through a combination of high-resolution hardware angle sensors and software algorithms for multiple compensation. At the software level, upshift and downshift angle threshold tables compensate for forward and reverse gear meshing errors. Braking utilizes short-circuit braking to eliminate inertial overshoot, significantly reducing the rotor oscillation range from ±3° to ±0.05°. This improved accuracy allows the invention to support tap changers with a large number of gears (e.g., 107 gears).

[0038] The angle positioning method of the motor control device of a power electronic tap changer described in the present invention solves the technical problem of improving the dynamic response speed and positioning accuracy of the transformer on-load tap changer motor control. The present invention can achieve efficient and reliable braking, overcome the voltage regulation delay and control inaccuracy problems caused by traditional electromechanical coupling and insufficient signal integrity, adopt MOSFET power tubes to replace mechanical relays, significantly improve the response speed and service life, utilize angle correction and gear matching algorithms to eliminate mechanical cumulative errors and improve positioning accuracy, adopt RS-485 digital communication bus to replace analog signal transmission, improve anti-interference ability, ensure the integrity of control signals, adopt short-circuit braking technology to replace traditional energy consumption braking, effectively avoid overheating and burning of braking resistors, and improve braking reliability and safety.

Claims

1. A method for angular positioning of a motor control device of a power electronic tap changer, characterized in that: The steps include: Step 1: After the motor control device is powered on, the MCU completes the peripheral initialization and reads the original message value A of the angle sensor. raw And get the adjusted angle value A according to the sensor direction flag angleclockwiseadd adj ; Calculate the maximum value of the circumference A max , zero point offset δ, and then calculate the theoretical interval θ of each gear according to the preset gear algorithm, and generate the gear angle threshold tables for upshifting and downshifting, namely the upshift table and the downshift table; Step 2: The MCU continuously detects the gear adjustment command from the local human-machine interface or the host computer, parses the target gear position Dt, compares the difference ΔD between the target gear position Dt and the current gear position Dc, and determines the running direction and the number of gear steps to move; Step 3: Based on the running direction, the MCU controls the corresponding MOSFET tubes in the H-bridge circuit to turn on, and at the same time, the MCU outputs a PWM drive signal to make the H-bridge circuit drive the motor to rotate in the target direction; Step 4: During the motor operation, the MCU periodically collects A raw , perform original angle conversion, calculate zero point offset δ, perform practical angle conversion, and obtain the final angle A final MCU determines whether to use the upshift table or downshift table for matching, and then searches the matching interval according to the corresponding gear angle threshold table to update the current gear position Dc; Step 5: When the proximity sensor or the gear threshold matching table confirms that the motor shaft has reached the target gear position Dt, the MCU performs the following actions in a staged braking sequence: Gear position a: cut off PWM drive; B gear position: turns on the MOSFET tube of the same arm to perform low-resistance energy-consuming braking; Step 6: After the MCU verifies that Dc=Dt, it stops outputting the PWM signal, saves the final gear position and operation record, and enters standby mode, waiting for the next gear adjustment instruction.

2. The method for angular positioning of a motor control device of a power electronic tap changer according to claim 1, characterized in that: The motor control device includes MUC, 485 communication chip, GPIO interface and PWM interface; The 485 communication chip, GPIO interface and PWM interface are all connected to the MCU; The 485 communication chip is connected to and communicates with the angle sensor; the PWM interface is connected to the H-bridge circuit to provide a PWM drive signal to the H-bridge circuit, which drives the motor of the tap changer; The GPIO interface is connected to a proximity sensor, which is used to detect the position of the tap changer and obtain the current gear position reached by the motor shaft.

3. The angle positioning method of the motor control device of a power electronic tap changer according to claim 1, characterized in that: When executing step 2, the MCU continuously detects the gear adjustment instruction from the local human-machine interface or the host computer, and the gear adjustment instruction includes the target gear position Dt.

4. The method for angular positioning of a motor control device of a power electronic tap changer according to claim 2, wherein: When executing step 1, the specific steps include: Step 1-1: MCU power-on initialization, including initialization of the communication status of the 485 communication chip, the status of the GPIO interface, and the status of the PWM interface; Step 1-2: Read the original angle data collected by the angle sensor and save it as A raw ; Step 1-3: Calculate the adjustment value A adj , the specific method is as follows: If angleclockwiseadd = true, then A adj =A raw On the contrary, A adj =A max -A raw ; Among them, A adj is the angle value after adjustment, A raw is the original message angle value, A max is the maximum value of the circumference, A max =360×R, R=100; Step 1-4: Calculate the zero point offset δ. The specific calculation method is as follows: If AH > AL, then V = A max - (AH - AL); If (AH+V / 2)<A max , then δ=A max -(AH+V / 2)+AL; conversely, δ=AL-(V / 2-(A max -AH)); If AH≤AL, then V=AL-AH, δ=AL-(AH-V / 2); Among them, δ is the zero point offset, V represents an intermediate variable, AH is the angle value of the high gear, and AL is the angle value of the low gear; Steps 1-5: Calculate the practical angle value A final , the specific method is as follows: If AH > AL, then A final = A adj - AL - δ; If A adj ∈[AL - 5R, A max , then A final = A adj - AL + δ; Conversely, then A final =A max -AL + A adj + δ; Step 1-6: Calculate the theoretical angle θ for each gear and generate a gear angle table. The specific method is as follows: Calculate the theoretical angle θ: If AH>AL, then θ=(AH-AL) / (N-1); On the contrary, θ=(A max -AH-AL) / (N-1); Where θ is the theoretical angle of each gear, and N represents the total number of gears; Calculate the gear angle threshold table, specifically calculate the angle threshold range Ti of gear i, and obtain the upshift table, downshift table and standard table: Standard table: Ti = δ + i × θ ± θ × k; Upshift table: Ti = f (Au) + (i-1) × θ up ±θ up ×k up ; Downshift table: Ti=δ+i×θ down ±θ down ×k down ; Where Au is the second gear angle when shifting up, θ down is the downshift angle per gear, θ up is the angle of each gear when upshifting, Ad is the angle of the second-to-last gear when downshifting, f(·) is the angle conversion function, k up =k down =10 / 33.0, k=16.499 / 33.

0.

5. The method for angular positioning of a motor control device of a power electronic tap changer according to claim 3, characterized in that: When executing step 2, the specific steps are as follows: Step 2-1: The MCU continuously detects the gear adjustment command from the local human-machine interface or the host computer, and obtains the target gear position Dt after analysis; Step 2-2: The MCU compares the target gear position Dt with the target gear position Dc, calculates the gear position difference ΔD, and determines the target direction of motor rotation and the number of gear positions required to be crossed based on the difference ΔD.

6. The method for angular positioning of a motor control device of a power electronic tap changer according to claim 2, characterized in that: When executing step 4, the specific steps include: Step 4-1: The MCU periodically collects the raw angle data of the angle sensor and performs standardization conversion and zero point correction; Step 4-2: Determine whether the standard angle value crosses zero degrees. If so, select the appropriate conversion method for correction; Step 4-3: Based on the corrected angle value, match the corresponding gear range in the upshift table or downshift table, and update the current gear information in real time. The specific gear matching method is as follows: If M dir = ascend, then θ = {i | A final ∈ [T （i，low） , T （i，high） in up - table}; Conversely, then θ = {i|A final ∈[T （i，low） , T （i，high） in down - table}.

7. The method for angular positioning of a motor control device of a power electronic tap changer according to claim 2, characterized in that: When executing step 5, the specific steps include: Step 5-1: MCU continuously detects the output signal of the proximity sensor; Step 5-2: When the proximity sensor detects that the motor shaft is close to the mechanical positioning point of the target gear, the MCU first cuts off the PWM drive signal and enters the low-speed control stage, that is, stage b; In the low-speed control stage, the MCU controls the diagonal MOSFETs of the H-bridge to conduct, achieving low-resistance energy-dissipating braking, allowing the motor to decelerate smoothly when approaching the target position; Step 5-3: When the proximity sensor signal confirms that the motor has entered the precise position range, the MCU closes the brake channel and prepares to enter the stop state, which is stage a.

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