A method for angular positioning of a motor control device of a power electronic tap changer

Abstract

The application discloses a kind of motor control device's angle positioning method of power electronic tap changer, belong to electric power technical field, including initialization and parameter generation, gear instruction analysis, motor drive, real-time angle matching, braking in stages and gear completion, solve the technical problem of improving the dynamic response speed and positioning accuracy of transformer on-load tap changer motor control, the application can realize efficient and reliable braking, significantly improve response speed and service life, using angle correction and gear matching algorithm, eliminate mechanical cumulative error, improve positioning accuracy, improve anti-interference ability, ensure control signal integrity, using short-circuit braking technology instead of traditional energy consumption braking, effectively avoid brake resistance overheating burnout, improve braking reliability and safety.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electric power, and particularly relates to an angle positioning method of a motor control device of a power electronic tap changer. BACKGROUND

[0002] The voltage regulation of the current transformer on-load tap changer mainly depends on the following two types of traditional technologies:

[0003] Relay-contactor driving system: the mechanical relay group is used to control the forward and reverse rotation of the direct current motor, and the gear position is detected through the physical limit switch (such as a micro switch or a travel switch), and the gear signal is transmitted to the controller in a hard-wired manner.

[0004] Basic electronic braking scheme: the external energy consumption braking resistor is used to realize the motor shutdown, and the angle detection is generally realized by using a potentiometer or an incremental encoder.

[0005] The existing technology has the following obvious deficiencies:

[0006] Poor dynamic response performance: the mechanical relay contact action time is usually greater than or equal to 100 ms, and the total time of reversing is more than 1 second, which causes serious delay of voltage regulation. The total time of 12-gear switching of a certain type is as high as 15 seconds. At the same time, the service life of the relay contact due to arc ablation is less than 100,000 times, and the frequent replacement increases the operation and maintenance cost.

[0007] Insufficient positioning accuracy: the mechanical limit switch has a large assembly tolerance (±0.5 mm), and the corresponding angle error is more than 1.5°. The backlash of the gear transmission system causes error accumulation, and the deviation after 12-gear switching is as high as 2.4°, which seriously affects the stability of the output voltage. For example, the voltage fluctuation of a certain 35kV substation reaches ±5% due to the gear deviation.

[0008] Weak anti-interference ability: the potentiometer signal is transmitted in the form of analog quantity, and the reading jump caused by electromagnetic interference is more than 10% within 10 meters. The incremental encoder needs to be re-zeroed after power failure, and the sudden power failure causes the loss of gear information.

[0009] Low braking reliability: the traditional energy consumption braking resistor continuously generates heat, and the temperature rise is more than 80℃, which accelerates the aging of the line. Statistics of a certain wind farm show that 23% of the braking failures are caused by resistor burnout, which has safety hazards. SUMMARY

[0010] The application aims to provide an angle positioning method of a motor control device of a power electronic tap changer, and solves the technical problem of improving the dynamic response speed and positioning accuracy of the motor control of the transformer on-load tap changer.

[0011] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0012] A kind of motor control device of power electronic tap changer angle positioning method, comprising the following steps:

[0013] Step 1: after the motor control device is powered on, MCU completes peripheral initialization, MCU reads the original message value A of angle sensor raw And according to sensor direction mark angleclockwiseadd, the adjusted angle value A is obtained adj ;Calculate the maximum value A of circumference max , zero offset δ, then according to the preset gear algorithm, the theoretical interval θ of each gear is calculated, and the gear angle threshold table of gear up and gear down, i.e. gear up table and gear down table is generated respectively;

[0014] Step 2: MCU continuously detects the gear adjusting instruction from local man-machine interface or host computer, parses the target gear Dt, compares the difference ΔD of target gear Dt and current gear Dc, and determines the running direction and the gear step number of movement;

[0015] Step 3: according to the running direction, MCU controls the conduction of corresponding MOSFET tube in H bridge circuit, and simultaneously MCU outputs PWM driving signal, so that H bridge circuit drives motor to rotate towards target direction;

[0016] Step 4: during the operation of motor, MCU periodically collects A raw , carries out original angle conversion, calculates zero offset δ, carries out practical angle conversion, and obtains the final practical angle A final ;MCU judges to use gear up table or gear down table for matching, and then finds the matching interval according to the corresponding gear angle threshold table to update current gear Dc;

[0017] Step 5: when the proximity sensor or the gear threshold value matching table confirms that the motor rotating shaft reaches the position of target gear Dt, MCU executes the following actions in phased braking sequence:

[0018] Phase a: cut off PWM drive;

[0019] Phase b: turn on the MOSFET tube of the same arm to carry out low-resistance energy braking;

[0020] Step 6: after MCU checks Dc=Dt, stop outputting PWM signal, save the position of final gear and operation record, and enter standby, wait for next gear adjusting instruction.

[0021] Preferably, the motor control device comprises MCU, 485 communication chip, GPIO interface and PWM interface;

[0022] The 485 communication chip, GPIO interface and PWM interface are connected with MCU;

[0023] 485 communication chip is connected with the angle sensor and communicates with the angle sensor; the PWM interface is connected with the H-bridge circuit, and is used for providing a PWM driving signal for the H-bridge circuit, and the H-bridge circuit drives the motor of the tapping switch;

[0024] The GPIO interface is connected with the proximity sensor, and the proximity sensor is used for detecting the position of the tapping switch, so as to obtain the current gear position reached by the rotating shaft of the motor.

[0025] Preferably, when step 2 is performed, the MCU continuously detects a gear shifting instruction from the local man-machine interface or the upper computer, and the gear shifting instruction contains a target gear Dt.

[0026] Preferably, when step 1 is performed, the following steps are specifically included:

[0027] Step 1-1: the MCU is powered on and initialized, including initializing the communication state of the 485 communication chip, the state of the GPIO interface and the state of the PWM interface;

[0028] Step 1-2: reading the original angle data collected by the angle sensor and saving as A raw ;

[0029] Step 1-3: calculating an adjustment value A adj , and the specific method is as follows:

[0030] If angleclockwiseadd=true, then A adj =A raw ; otherwise, A adj =A max -A raw ;

[0031] Wherein, A adj is an adjusted angle value, A raw is an original message angle value, A max is a maximum value of a circle, A max =360×R, and R=100.

[0032] Step 1-4: calculating a zero offset δ, and the specific calculation method is as follows:

[0033] If AH>AL, then V=A max -(AH-AL);

[0034] If (AH+V / 2)<A max , then δ=A max -(AH+V / 2)+AL; otherwise, δ=AL-(V / 2-(A max -AH));

[0035] If AH≤AL, then V=AL-AH, and δ=AL-(AH-V / 2);

[0036] wherein, δ is a zero offset, V represents an intermediate variable, AH is the angle value of high gear, AL is the angle value of low gear;

[0037] Step 1-5: Calculate the practical angle value A final , the specific method is as follows:

[0038] If AH>AL, then A final =A adj -AL-δ;

[0039] If A adj ∈[AL-5R,A max ], then A final =A adj -AL+δ;

[0040] Otherwise, then A final =A max -AL+A adj +δ;

[0041] Step 1-6: Calculate the theoretical angle θ of each gear, and generate the gear angle table, the specific method is as follows:

[0042] Calculate the theoretical angle θ:

[0043] If AH>AL, then θ=(AH-AL) / (N-1);

[0044] Otherwise, then θ=(A max -AH-AL) / (N-1);

[0045] wherein, θ is the theoretical angle of each gear, N represents the total number of gears;

[0046] Calculate the gear angle threshold table, specifically calculate the angle threshold range Ti of gear i, to obtain the upshift table, downshift table and standard table:

[0047] Standard table: Ti=δ+i×θ±θ×k;

[0048] Upshift table: Ti=f(Au)+(i-1)×θ up ±θ up ×k up ;

[0049] Downshift table: Ti=δ+i×θ down ±θ down ×k down ;

[0050] wherein, Au is the second upshift gear angle, θ down is the downshift angle of each gear, θ upfor each gear angle, f(·) is the angle conversion function, k up = k down = 10 / 33.0, k = 16.499 / 33.0.

[0051] Preferably, when performing step 2, the specific steps are as follows:

[0052] Step 2-1: The MCU continuously detects the gear shifting instruction of the local man-machine interface or the host computer, and obtains the target gear Dt after analysis.

[0053] Step 2-2: The MCU compares the target gear Dt with the current gear Dc, calculates the gear difference ΔD, and determines the target direction of motor rotation and the number of gears to be crossed according to the difference ΔD.

[0054] Preferably, when performing step 4, the specific steps include the following steps:

[0055] Step 4-1: The MCU periodically collects the original angle data of the angle sensor and performs standardization conversion and zero point correction.

[0056] Step 4-2: Determine whether the standard angle value crosses zero, and then select the appropriate conversion method for correction.

[0057] Step 4-3: According to 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:

[0058] If M dir = ascend, then θ1={i|A final ∈[T （i，low） , T （i，high） ] in up-table}.

[0059] Conversely, then θ1={i|A final ∈[T （i，low） , T （i，high） ] in down-table}.

[0060] Wherein, ascend represents the upshift direction, i represents the gear index number, A final represents the practical angle value, T （i，low） represents the lower limit angle threshold of the i-th gear, T （i，high） represents the upper limit angle threshold of the i-th gear, up-table represents the upshift table, and down-table represents the downshift table.

[0061] Preferably, when performing step 5, the specific steps include the following steps:

[0062] Step 5-1: MCU continuously detects the output signal of the proximity sensor;

[0063] 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, i.e. stage b;

[0064] In the low-speed control stage, the MCU controls the conduction of the diagonal MOSFET of the H-bridge to realize low-resistance energy braking, so that the motor can smoothly decelerate when approaching the target position;

[0065] Step 5-3: When the proximity sensor signal confirms that the motor has entered the precise position interval, the MCU closes the braking channel and prepares to enter the stop state, i.e. stage a.

[0066] The angle positioning method of the motor control device of the power electronic tap changer according to the present application solves the technical problem of improving the dynamic response speed and positioning accuracy of the motor control of the on-load tap changer of the transformer, and can realize efficient and reliable braking, overcome the problems of voltage regulation delay and control inaccuracy caused by the insufficient signal integrity of traditional mechanical coupling, replace mechanical relays with MOSFET power tubes to significantly improve the response speed and service life, eliminate mechanical cumulative error by using angle correction and gear matching algorithm, improve positioning accuracy, replace analog signal transmission with RS-485 digital communication bus to improve anti-interference ability and ensure control signal integrity, and replace traditional energy consumption braking with short-circuit braking to effectively avoid overheating and burning of the braking resistor and improve braking reliability and safety. BRIEF DESCRIPTION OF DRAWINGS

[0067] Figure 1 is the main flowchart of the present application;

[0068] Figure 2 is the timing logic diagram of the short-circuit braking of the present application;

[0069] Figure 3 is the flowchart of angle conversion of the present application;

[0070] Figure 4 is the matching flowchart of the upshift table and the downshift table of the present application;

[0071] Figure 5 is the principle diagram block diagram of the motor control device of the present application. DETAILED DESCRIPTION

[0072] The angle positioning method of the motor control device of the power electronic tap changer shown in Figures 1-5 includes the following steps:

[0073] Step 1: After the motor control device is powered on, the MCU completes peripheral initialization, the MCU reads the original message value A of the angle sensor raw And according to the sensor direction flag angleclockwiseadd, the adjusted angle value A is obtained adj ; The maximum value of the circumference A max , the zero offset δ, and then according to the preset gear algorithm to calculate the theoretical interval θ of each gear, respectively generate the gear angle threshold table of gear up and gear down, that is, the upshift table and the downshift table

[0074] When performing step 1, the following steps are specifically included:

[0075] Step 1-1: MCU power-on initialization, including initializing the communication state of the 485 communication chip, the state of the GPIO interface and the state of the PWM interface;

[0076] Step 1-2: Read the original angle data collected by the angle sensor and save it as A raw ;

[0077] Step 1-3: Calculate the adjustment value A adj , the specific method is as follows:

[0078] If angleclockwiseadd=true, then A adj =A raw ; Otherwise, A adj =A max -A raw ;

[0079] Wherein, A adj is the adjusted angle value, A raw is the original message angle value, A max is the maximum value of the circumference, A max =360×R, R=100;

[0080] Step 1-4: Calculate the zero offset δ, the specific calculation method is as follows:

[0081] If AH>AL, then V=A max -(AH-AL);

[0082] If (AH+V / 2) < A max , then δ=A max -(AH+V / 2)+AL; Otherwise, δ=AL-(V / 2-(A max -AH));

[0083] If AH≤AL, then V=AL-AH, δ=AL-(AH-V / 2);

[0084] Wherein, δ is a zero offset, V represents an intermediate variable, AH is the angle value of high gear, AL is the angle value of low gear;

[0085] Step 1-5: Calculate the utility angle value A final , the specific method is as follows:

[0086] If AH> AL, then A final = AH- AL- δ; adj

[0087] If A adj ∈ [AL- 5R, A max ], then A final = AH- AL+ δ; adj

[0088] Otherwise, then A final = AH- AL+ A max + δ; adj

[0089] Step 1-6: Calculate the theoretical angle θ of each gear, and generate the gear angle table, the specific method is as follows:

[0090] Calculate the theoretical angle θ:

[0091] If AH> AL, then θ= (AH- AL) / (N-1);

[0092] Otherwise, then θ= (A max -AH- AL) / (N-1);

[0093] Wherein, θ is the theoretical angle of each gear, and N represents the total number of gears;

[0094] Calculate the gear angle threshold table, specifically calculate the angle threshold range Ti of gear i, obtain the upshift table, downshift table and standard table:

[0095] Standard table: Ti= δ+ i × θ ± θ × k;

[0096] Upshift table: Ti= f (Au) + (i-1) × θ up ± θ up × k up ;

[0097] Downshift table: Ti= δ+ i × θ down ± θ down × k down ;

[0098] Wherein, Au is the second upshift angle, θ down is the downshift angle of each gear, θ up is the upshift angle of each gear, f (·) is an angle conversion function, and k up =k​​​down =10 / 33.0, k=16.499 / 33.0.

[0099] Step 2: MCU continuously detects the gear shifting instruction from the local human-machine interface or the host computer, parses the target gear Dt, compares the difference ΔD between the target gear Dt and the current gear Dc, and determines the running direction and the number of gear steps to move;

[0100] In this embodiment, the human-machine interface is provided by a touch screen, which is connected with the MCU; the MCU also communicates with the host computer through a UART interface;

[0101] MCU continuously detects the gear shifting instruction from the local human-machine interface or the host computer, which contains the target gear Dt.

[0102] When performing step 2, the specific steps are as follows:

[0103] Step 2-1: MCU continuously detects the gear shifting instruction from the local human-machine interface or the host computer, and parses the target gear Dt after receiving the instruction;

[0104] Step 2-2: MCU compares the target gear Dt with the current gear Dc, calculates the difference ΔD between the two gears, and determines the target direction of motor rotation and the number of gears to be crossed according to the difference ΔD.

[0105] Step 3: According to the running direction, MCU controls the conduction of the corresponding MOSFET tube in the H-bridge circuit, and at the same time, MCU outputs PWM driving signal to make the H-bridge circuit drive the motor to rotate in the target direction;

[0106] In this embodiment, the H-bridge circuit includes four MOSFET tubes, namely Q1, Q2, Q3 and Q4. When positive rotation is required to switch gears, the MOSFET power tubes of H-bridge upper left Q1 and lower right Q3 are turned on, so that the 24-volt DC voltage is loaded to the motor in the positive direction;

[0107] When reverse rotation is required to switch gears, the MOSFET power tubes of H-bridge upper right Q2 and lower left Q4 are turned on, so that the 24-volt DC voltage is loaded to the motor in the reverse direction;

[0108] The response time of the commutation action is less than or equal to 500 milliseconds.

[0109] The H-bridge circuit is a prior art, so it will not be described in detail.

[0110] Step 4: During the operation of the motor, MCU periodically collects A raw , performs original angle conversion, calculates zero point offset δ, performs practical angle conversion, and obtains the final practical angle A final ; MCU determines to use the upshift table or the downshift table for matching, and then looks up the matching interval according to the corresponding gear angle threshold table to update the current gear Dc;

[0111] In the step 4, the following steps are specifically included:

[0112] Step 4-1: The MCU periodically collects the original angle data of the angle sensor, and performs standardization conversion and zero point correction.

[0113] Step 4-2: Determine whether the standard angle value crosses zero, and then select the appropriate conversion method for correction.

[0114] Step 4-3: According to 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:

[0115] If M dir =ascend, then θ1={i|A final ∈[T （i，low） , T （i，high） ] in up-table}.

[0116] Otherwise, θ1={i|A final ∈[T （i，low） , T （i，high） ] in down-table}.

[0117] Wherein, ascend represents the upshift direction, i represents the gear index number, A final represents the actual angle value, T （i，low） represents the lower limit angle threshold of the i-th gear, T （i，high） represents the upper limit angle threshold of the i-th gear, up-table represents the upshift table, and down-table represents the downshift table.

[0118] In this embodiment, if the running direction = upshift: the current gear i = the index that satisfies A_final∈[the threshold interval of the i-th gear in the upshift table];

[0119] If the running direction = downshift: the current gear i = the index that satisfies A_final∈[the threshold interval of the i-th gear in the downshift table].

[0120] Upshift table: store the upshift angle interval [T （i，low） , T （i，high） ] in up-table of each gear i.

[0121] Downshift table: store the downshift angle interval [T （i，low） , T （i，high） ] in down-table of each gear i.

[0122] Step 5: When the proximity sensor or the gear threshold matching table confirms that the motor shaft reaches the target gear Dt position, the MCU performs the following actions in a phased braking sequence:

[0123] Phase a: PWM drive is cut off;

[0124] Phase b: Turn on the same arm MOSFET tube for low resistance energy dissipation braking;

[0125] When performing step 5, it specifically includes the following steps:

[0126] Step 5-1: The MCU continuously detects the output signal of the proximity sensor;

[0127] Step 5-2: When the proximity sensor detects that the motor shaft approaches the mechanical positioning point of the target gear, the MCU first cuts off the PWM drive signal and enters the low-speed control phase, i.e. phase b;

[0128] In the low-speed control phase, the MCU controls the conduction of the diagonal MOSFET of the H-bridge to achieve low resistance energy dissipation braking, allowing the motor to smoothly decelerate when approaching the target position;

[0129] Step 5-3: When the proximity sensor signal confirms that the motor has entered the precise position interval, the MCU closes the brake channel and prepares to enter the stop state, i.e. phase a.

[0130] 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 shifting instruction.

[0131] The motor control device includes an MCU, a 485 communication chip, a GPIO interface, and a PWM interface;

[0132] The 485 communication chip, GPIO interface, and PWM interface are connected to the MCU;

[0133] 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 PWM drive signals for the H-bridge circuit, which drives the motor of the tap switch;

[0134] The GPIO interface is connected to the proximity sensor, which is used to detect the position of the tap switch and obtain the current gear position reached by the motor shaft.

[0135] In this embodiment, the motor drive part selects IRF3205 type MOSFET power tube to build H bridge drive circuit, and the drive chip adopts HIP4081. The power circuit adopts 2oz copper thick copper foil, and the line width is not less than 3mm, which can bear the maximum current of 25A. In order to ensure the quality of the driving signal, the length of the gate drive line is controlled within 5cm, and the twisted shield cable is used for anti-interference design.

[0136] The brake response performance is high, the response time from brake signal triggering to full short is less than 10ms, and the time of coil current from 12A rapid decay to 0A is not more than 50ms. The mechanical part has high positioning accuracy, and the rotor offset angle after braking is less than 0.1 degree.

[0137] The gear signal detection adopts a patch type proximity sensor (model is Hall sensor DN8799) installed on the tap switch turntable at 360 degrees of any position, which is used for accurately capturing the gear to position signal. The angle sensor selects high-precision TLE5012B chip, and the resolution reaches 0.1 degree. The signal collected by the angle sensor is preliminarily processed by the STM32L151 low-power microcontroller, and then converted into RS-485 digital signal transmission through the MAX485 chip, which ensures the anti-interference ability of long distance communication. When installing, the angle sensor needs to be coaxial with the switch rotating shaft, so as to ensure the angle acquisition accuracy.

[0138] In this embodiment, STM32F407 microprocessor is used to execute gear control algorithm. After the system starts, the switch mechanical gear is rotated to 1 gear, and the current gear number is recorded. Through the pre-calculated gear angle threshold table generated by rising and falling, the current gear is quickly positioned and matched. According to the gear adjusting instruction input by the user, the motor drive circuit is controlled to make the tap switch smoothly and accurately adjust the gear.

[0139] The technical essence lies in that the all-electronic MOSFET power tube is used to replace the mechanical relay, there is no mechanical contact, the switching speed is nanosecond level (the conduction delay of IRF3205 is only 35ns), the PWM soft start and brake algorithm are combined, the motor start-stop impact current is effectively eliminated, the peak current is reduced from 40A to 25A, and the control response delay is less than 10ms.

[0140] The single gear positioning error is ±0.05°, which is reduced by 97% compared with the traditional relay scheme. Taking 12 gears as an example, the cumulative error of 12 gears is less than 0.1°, which is reduced by 96% compared with the traditional relay scheme, and the meshing error of forward and reverse gears is less than 0.1°, which is reduced by 97% compared with the traditional relay scheme.

[0141] The present application realizes the limit industrial positioning precision through the high resolution angle sensor of hardware and the multiple compensation of software algorithm. On the software level, the upshift and downshift gear angle threshold table respectively makes up the mechanical gear forward and reverse meshing error. The brake adopts the short circuit brake to eliminate the inertia overshoot, and the rotor oscillation range is greatly reduced from ±3° to ±0.05°. The present application can support the tap switch with more gears (such as 107 gears) due to the improved precision.

[0142] The angle positioning method of the motor control device of the power electronic tap switch disclosed in the present application solves the technical problem of improving the dynamic response speed and positioning precision of the on-load tap changer motor control of the transformer. The present application can realize efficient and reliable braking, overcome the problems of voltage regulation delay and control misalignment caused by the insufficient signal integrity of traditional mechanical and electrical coupling, replace the mechanical relay with MOSFET power tube, significantly improve the response speed and service life, eliminate the mechanical cumulative error by using the angle correction and gear matching algorithm, improve the positioning precision, replace the analog signal transmission with RS-485 digital communication bus to improve the anti-interference ability and ensure the completeness of the control signal, and replace the traditional energy consumption brake with the short circuit brake technology to effectively avoid the overheat and burnout of the brake resistor, and improve the 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; 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); Among them, θ is the theoretical angle of each gear, N is the total number of gears, A max is the maximum value of the circle, AH is the angle value of the high gear, and AL is the angle value of the low gear; 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 practical 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; 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; Otherwise, it is A final = A max -AL + A adj + δ; A max =360×R,R=100; 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: Phase a: Cut off PWM drive; Phase b: Turn on the MOSFET tube in the same arm to perform low-resistance energy-dissipating 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 MCU, 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; Step 1-5: 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 shifting up, 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 parsing; Step 2-2: The MCU compares the target gear position Dt with the current 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 4, 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, and 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 θ1 = {i | A final ∈ [T （i，low） , T （i，high） in up - table}; On the contrary, θ1={i|A final ∈[T （i，low） , T （i，high） ] in down-table}; Among them, ascend indicates the direction of upshift, i indicates the gear index number, A final Indicates the practical angle value, T （i，low） Indicates the lower angle threshold of the i-th gear, T （i，high） Indicates the upper limit angle threshold of the i-th gear, up-table indicates the upshift table, and down-table indicates the downshift 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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