Direct start hall sensor permanent magnet synchronous motor fault-tolerant operation method

Abstract

The application discloses a kind of directly started hall sensor permanent magnet synchronous motor fault-tolerant operation method, the method is as follows: the rotor information estimation system of multiple hall sensors with sector position error is degraded into the system consisting of 1 hall sensor, for the rising edge or falling edge of each hall sensor, rotor turns only can output an effective hall signal for one electrical period, the position between two hall signals is regarded as a generalized sector;The rising edge or falling edge of each single hall sensor estimates the rotor information in a narrow sense sector adjacent to its sector edge using zero-order closed-loop algorithm;According to the output of hall sensor rotor information estimation system, different hall sectors are numbered and output, after detecting rising edge or falling, the current entering hall sector number is accurately output, and fault-tolerant operation is carried out on this basis.The method can directly drive the motor to operate in actual working state, which is conducive to the continuous and high performance-price ratio operation of hall motor.

Description

TECHNICAL FIELD

[0001] The application relates to a sector position error fault-tolerant operation method, in particular to a Hall sensor permanent magnet synchronous motor fault-tolerant operation method capable of direct starting. BACKGROUND

[0002] The existing fault-tolerant operation method for sector position error usually identifies the sector position error first, compensates and corrects the sector position error in software, and realizes fault-tolerant operation of the sector position error on the basis.

[0003] Among them, the offline correction method is most widely used in production and life: in the offline state, such as before the Hall motor system leaves the factory, manually rotate the shaft of the corrected motor or drag the corrected motor by an additional prime mover, usually do uniform motion, observe the phase difference between the Hall signal and the back electromotive force zero point, and then compensate the phase difference in the software to realize the coincidence of the Hall signal and the back electromotive force zero point position. The offline method cannot support the wide popularization of the permanent magnet synchronous motor based on the low-resolution Hall sensor in the low-end scene because of its low efficiency, inability to rely on the motor itself, and other characteristics. At the same time, it is not suitable for scenes where low-resolution Hall sensors are prone to position time-varying deviation because it cannot identify, correct, fault-tolerant control and run the position error deviation after the sector position error correction.

[0004] The development of the existing online correction method has not been widely applied in actual production and life. For example, the online correction method proposed by Philip B can realize sector position error correction only by relying on the corrected motor itself, but it still needs the motor to run at a uniform speed during the correction process, and the collection and calculation of motor acceleration information are easily affected by noise, disturbance and other factors, making it difficult to obtain accurate sector position error information.

[0005] If the online work is defined as the motor working normally according to the given instruction, the meaning of offline work is opposite. The above offline correction method and online correction method are offline methods, that is, during the sector position error correction process, the motor cannot complete the given task, and the fault-tolerant control and operation of the motor depend on the "preprocessing" link of sector error correction. This feature is not conducive to the continuous operation of the Hall motor which is prone to sector position error, and cannot support the application of the Hall motor in high-end occasions and extreme environments. In addition, the current driving method of the permanent magnet synchronous motor based on the low-resolution Hall sensor does not pay attention to the Hall sector number, that is, the Hall signal is converted into a square wave with the Hall sector as the period through the exclusive OR operation, and only the judgment of the rotor entering the next sector from the current sector is made, such as Figure 1The processing procedure is simplified, but the freedom of processing the Hall signal is reduced, and it is difficult to make more dimensional estimation and drive control according to the Hall signal. SUMMARY

[0006] The application provides a Hall sensor permanent magnet synchronous motor fault-tolerant operation method capable of direct starting based on analysis of existing sector position error fault-tolerant operation methods and sector position error correction methods, full research of offline methods and online methods, and a permanent magnet synchronous motor control strategy based on Hall sector position error closed-loop feedback.

[0007] The application aims to realize the following technical solutions.

[0008] A Hall sensor permanent magnet synchronous motor fault-tolerant operation method capable of direct starting comprises the following steps.

[0009] Step one: a multi-Hall sensor rotor information estimation system composed of r Hall sensors with sector position error is degraded into a system composed of one Hall sensor. For the rising edge or falling edge of each Hall sensor, the rotor rotates through one electrical period and can only output one effective Hall signal. The position between the two Hall signals is regarded as one generalized sector, the radian of the sector is not affected by the sector position error, and is always 2π radians.

[0010] Step two: a zero-order closed-loop algorithm is used to estimate the rotor information in a narrow sector adjacent to the sector edge of each Hall sensor.

[0011] Step two one: according to the zero-order open-loop algorithm, i.e., the average speed method, the rotor speed in the current sector is The average speed v β in the previous sector is used to estimate:

[0012]

[0013] In the formula, v β is the average speed of the rotor in the previous Hall sector, is the position of the rotor leaving the previous Hall sector, is the position of the rotor entering the previous Hall sector, and T βi is the time used by the rotor to rotate through the previous Hall sector.

[0014] Step two, the position estimation result of the rotor is obtained by integrating the rotor speed:

[0015]

[0016] In the formula, t k is the time of the rotor in the current Hall sector; t s is the time when the rotor enters the current Hall sector; is the estimated position of the rotor at present; x s is the starting position of the current Hall sector;

[0017] Step two three, when the rotor turns to the starting position of the current Hall sector, the deviation of the estimated position of the rotor in the previous Hall sector from the actual value is:

[0018]

[0019] In the formula, Δx ki-1 is the deviation of the estimated position of the rotor from the actual position in the previous Hall sector time; is the estimated position of the rotor in the previous Hall sector time;

[0020] Step two four, the rotor speed deviation in the previous sector is estimated according to the rotor position estimation deviation:

[0021]

[0022] In the formula, Δv k is the average estimated rotor speed error of the rotor in the previous Hall sector; T βi is the time used by the rotor to turn through the previous Hall sector;

[0023] Step two five, the estimated rotor speed in the current sector is:

[0024]

[0025] In the formula, is the estimated rotor speed of the rotor in the current Hall sector; is the estimated average rotor speed of the rotor in the previous Hall sector;

[0026] The above formula is written as:

[0027]

[0028] Then the rotor position at t k time in the current sector is estimated as:

[0029]

[0030] In the formula, x s ​the start position of the current sector;

[0031] Step three, the original Hall signal processing method is improved, the output of the rotor information estimation system in different Hall sectors is numbered and output, after detecting the rising edge or falling edge, the current entering Hall sector number is accurately output, on this basis, fault tolerance operation is carried out, the specific steps are as follows:

[0032] Step three one, for h a + Sector edge, the rotor turns through the previous Hall sector h a + Sector edge, based on the information of the past one electrical period, the rotor information estimation value is obtained, which is used for estimating h a + Sector edge, the information of the rotor in the next Hall sector h a + The rising edge of Hall sensor a, h a - The falling edge of Hall sensor a; in this way, the estimation value of the rotor information in each Hall sector in the current electrical period is obtained based on the information of the past one electrical period of the initial sector edge of the Hall sector;

[0033] Based on this step, the direct starting of permanent magnet synchronous motor with Hall sector position error is realized;

[0034] Step three two, when entering the next Hall sector from the current Hall sector, the angle of the current Hall sector is calculated by the following formula:

[0035]

[0036] Where, T ki is the time used by the rotor to turn through the current Hall sector;

[0037] Based on this step, the Hall sector position error is identified, and higher performance fault tolerance operation is realized;

[0038] Step three, the average value of the historical data is calculated, so that the sector angle estimation value gradually converges to the actual value:

[0039]

[0040] Where, p is the data point number of the historical data taken;

[0041] Step three four, for the multi-Hall sensor rotor information estimation system composed of r Hall sensors, the uniform rotation of the motor is realized by the least square method using 2r Hall signals with quantization error, and the zero error and orthogonal error of the Hall sensor are corrected, the specific steps are as follows:

[0042] Step 341: Degenerate the multi-Hall sensor rotor information estimation system composed of r Hall sensors into a system with only one Hall sensor. Use only one Hall sensor to estimate the rotor's angular velocity, angular acceleration, and position. Under the detection of a single Hall sensor, quasi-uniform rotation is achieved.

[0043] T j ≈T j-1 ;

[0044] Among them, T j T is the period of detecting two consecutive rising edges or falling edges of any Hall sensor; j-1 is the previous cycle time;

[0045] Step 342: Use the least squares method to take the 2rN Hall signals obtained when the motor rotates N times to estimate the time it takes for the motor to rotate one circle.

[0046]

[0047] Step 343: Get performance indicators The smallest T k , T k That is the time it takes for the motor to rotate one circle, so the angular velocity of the motor is uniform The estimate is:

[0048]

[0049] Step 344: Use the least square method to calculate the 2rN Hall signals Simultaneous estimation:

[0050]

[0051] Among them, T ij (i=1,2,...,2r,j=1,2,...,2r) represents the time taken from the i-th Hall signal to the j-th Hall signal along the direction of motor rotation, and the performance index is taken as smallest is the vector composed of the angles of the Hall signal, which is obtained by detecting the rising and falling edges of the Hall signal;

[0052] Step 3, 4, and 5: Assuming the rising edge of Hall sensor a is at the correct position, estimate the falling edge position.

[0053]

[0054] Among them, θ au is the expected angle of the rising edge of Hall sensor a;

[0055] Detecting accurate falling edge position Calculate zero error θ of Hall sensor a Δa :

[0056]

[0057] Wherein, θ ad is the expected angle of the falling edge of Hall sensor a;

[0058] Assuming that the rising edge of Hall sensor a is at the accurate position, the rising edge position of Hall sensor b is estimated as:

[0059]

[0060] There is an orthogonal error ΔΘ between the two Hall sensors a and b:

[0061]

[0062] Wherein, θ bu is the expected angle of the rising edge of Hall sensor b;

[0063] The zero error and the orthogonal error of each Hall sensor identified are stored in the software, and the detected Hall signal is corrected when calculating, that is, the correction of the sector position error of the Hall fan is realized online.

[0064] Compared with the prior art, the present application has the following advantages:

[0065] 1. The present application degrades the multi-Hall sensor rotor information estimation system with sector position error to a single Hall system, and then combines it into a multi-Hall sensor system, which utilizes the inherent characteristic that the phase difference between the same Hall signals in adjacent electrical periods is always 2π radians, thereby avoiding the influence of the sector position error, and on this basis, a sector position error identification and correction method is proposed.

[0066] 2. The present application realizes online sector position error correction and fault-tolerant operation based on the interpolation feedback method without "preprocessing", and can directly drive the motor to operate in the actual working state, which is conducive to the continuous and high-performance operation of the Hall motor, and provides strong support for the mass production and application of the Hall motor in low-end scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0067] Figure 1 is an XOR operation processing diagram for Hall signals;

[0068] Figure 2 is a Hall sector division diagram without sector position error;

[0069] ​Figure 3 Hall sector division schematic with sector position error;

[0070] Figure 4 Hall sensor output sector number schematic;

[0071] Figure 5 Combined system estimation method schematic;

[0072] Figure 6 Hall sensor quantization error schematic;

[0073] Figure 7 Hall sensor a zero error schematic;

[0074] Figure 8 Orthogonal error between two Hall sensors a and b schematic;

[0075] Figure 9 Sector position error identification schematic;

[0076] Figure 10 Average speed method estimation results with (without) sector position error;

[0077] Figure 11 Average acceleration method estimation results with (without) sector position error;

[0078] Figure 12 Fault-tolerant operation method estimation results with (without) sector position error;

[0079] Figure 13 Fault-tolerant operation method estimation results with (without) sector position error;

[0080] Figure 14 Sector IV angle estimation for step speed;

[0081] Figure 15 Sector IV angle estimation for triangular wave speed;

[0082] Figure 16 Sector IV angle estimation for step speed load mutation;

[0083] Figure 17 Closed loop operation results with sector position error using an optical encoder;

[0084] Figure 18 Closed loop operation results with sector position error using a fault-tolerant operation method;

[0085] Figure 19 Closed loop operation results with sector position error using an average speed method;

[0086] In the figure, Tβi is the time used for the rotor to rotate through the previous sector; is the estimated average speed of the rotor in the previous sector; is the estimated speed of the rotor in the current sector; is the estimated position of the rotor in the current sector;x k is the actual position of the rotor in the current sector; is the Hall sensor output position of the rotor in the current sector; is the Hall sensor output position of the rotor in the previous sector;△x ki-1 is the deviation of the estimated position from the actual position of the rotor in the previous sector time;△v k is the average estimated speed error of the rotor in the previous sector. DETAILED DESCRIPTION

[0087] The technical solutions of the present application are further described below in conjunction with the drawings, but are not limited thereto, and any modification or equivalent replacement of the technical solutions of the present application without departing from the spirit and scope of the technical solutions of the present application shall be encompassed in the protection scope of the present application.

[0088] The present application provides a fault-tolerant operation method of a Hall sensor permanent magnet synchronous motor capable of direct starting, which takes a Hall sensor rotor information estimation system composed of three Hall sensors as an example, and performs vector control fault-tolerant operation on a permanent magnet synchronous motor based on a low-resolution Hall sensor rotor information estimation system with existing orthogonal error and zero error. When there is no Hall sector position error, sector division is as shown in Figure 2 When the discrete Hall sensors Ha, Hb, and Hc all have zero error, and there is orthogonal error among them, the Hall sector division is as shown in Figure 3 At this time, although the motor rotates one revolution, six Hall signals at a fixed angle will be detected, but the absolute electrical angle position of the six Hall signals and the relative electrical angle phase difference therebetween are unknown, and the rotor position and speed information cannot be estimated by using the sector angle.

[0089] Although the absolute electrical angle position of the six Hall signals in each electrical period and the relative electrical angle phase difference therebetween are unknown when there is sector position error, in multiple electrical periods, the electrical angle phase difference between the same Hall signals is always a constant, which is 2π radians of an electrical period. That is, the multi-Hall sensor rotor information estimation system can be degraded to a single-Hall sensor rotor information estimation system, and the rotor can only output one effective Hall signal when rotating one electrical period, and the position between two Hall signals is regarded as a generalized sector, the radian of the sector is not affected by the sector position error such as installation error and zero error of the discrete Hall sensor, and is always 2π radians.

[0090] When the multi-Hall sensor rotor information estimation system is completely degraded into a single-Hall sensor rotor information estimation system, a zero-order closed-loop algorithm is used to estimate rotor information.

[0091] When the rotor rotates to the start of the current sector, the rotor position estimation value in the previous sector The deviation Δx from the actual value ki-1 is:

[0092]

[0093] The rotor speed deviation Δv in the previous sector is estimated from the rotor position estimation deviation k :

[0094]

[0095] where T βi is the time taken by the rotor to rotate through the previous sector;

[0096] Based on the closed-loop feedback framework, the rotor speed estimation in the current sector is:

[0097]

[0098] Equation (3) can be written as:

[0099]

[0100] Then, the rotor position estimation at time t k in the current sector is:

[0101]

[0102] where x s is the start position of the current Hall sector;

[0103] To reduce estimation hysteresis, the multi-Hall sensor rotor information estimation system with sector position errors is regarded as a system composed of 1 Hall sensor, and the rising edge or falling edge of each Hall sensor is used to estimate the rotor information in a narrow sector adjacent to the sector edge.

[0104] The original Hall signal processing method is improved. The original Hall signal processing method does not distinguish between sectors, and performs XOR operation on the three Hall signals to make the output a rectangular wave. When the rising edge or falling edge is detected, it is determined that the rotor has entered the next sector, as shown in Figure 3As shown. Now it is necessary to number and output different sectors. The sectors are numbered by the output of the Hall sensor system in different sectors. For example, for sector I, the outputs of Hall sensors a, b, and c are 1, 0, and 1 respectively, so sector I is numbered 101. After detecting the rising or falling edge, it is necessary to accurately output the current sector number entered, and perform fault-tolerant operation based on this. Figure 4 shown.

[0105] With h a + sector edge as an example to analyze, since the rotor rotates through the previous sector h a + Sector edge, based on the information of the past electrical cycle, the rotor information estimate is obtained to estimate h a + sector edge after the sector (I sector) of the rotor information. Similarly, the estimated value of the rotor information in each sector in the current electrical cycle is based on the information of the sector's initial sector edge in the past electrical cycle, such as Figure 5 shown.

[0106] To further reduce estimation lag time and improve the motor's dynamic performance, it's necessary to switch the rotor information estimation method to the average velocity method or average acceleration method after effectively identifying the Hall sector angle. The motor's operating performance using these methods is highly dependent on accurate Hall sector angles. Therefore, it's necessary to identify the Hall sector angle with high accuracy while simultaneously enabling direct start and operation with Hall sector position error tolerance to support subsequent methods.

[0107] When entering the next sector from the current sector, the angle of the current sector can be calculated by formula (6):

[0108]

[0109] Among them, T ki The time it takes for the rotor to rotate through the current sector.

[0110] The motor is analyzed from step start to uniform speed motion. The speed estimation value is With the actual speed v k There is a large deviation, which causes the estimated sector angle to deviate greatly from the actual value. However, it can still be used under certain circumstances. The average value of historical data can be calculated to make the estimated sector angle gradually converge to the actual value:

[0111]

[0112] Where p is the number of data points of the historical data taken.

[0113] To get more accurate sector angle, the motor needs to run in a steady state, and the influence of the counter quantization error needs to be considered, i.e. due to the existence of the counter quantization error, the counting accuracy will affect the detection of the Hall signal, and the six Hall signals in an electrical cycle will be randomly generated within a certain range, which makes it difficult to rely on a single Hall signal to make the motor rotate at a uniform speed, especially when the low timer frequency division coefficient will produce a larger error, such as Figure 6

[0114] The six Hall signals with quantization error can be used to achieve uniform rotation of the motor by the least square method, and the zero error and orthogonal error of the Hall sensor are corrected.

[0115] The Hall sensor rotor information estimation system composed of multiple Hall sensors is degraded to a system with only one Hall sensor, and the rotor angular velocity, angular acceleration and position are estimated by only one Hall sensor. Under the detection of a single Hall sensor, the quasi-uniform rotation is realized, and there are:

[0116] T j ≈T j-1 (8)

[0117] Where T j is the period of detecting any Hall sensor continuous two rising or falling edges, and T j-1 is the time of the previous period.

[0118] The least square method is adopted to estimate the time T used by the motor to rotate one cycle by 6N Hall signals obtained by the motor rotating N cycles

[0119]

[0120] Take T k that makes the performance index minimum, and T k is the time used by the motor to rotate one cycle, then the uniform rotation angular velocity of the motor is estimated as:

[0121]

[0122] The least square method is adopted to estimate the time T used by the motor to rotate one cycle by 6N Hall signals obtained by the motor rotating N cycles at the same time:

[0123]

[0124] Where T ij (i=1,2,...,6,j=1,2,...,6) represents the time used from the ith Hall signal to the jth Hall signal along the direction of motor rotation. Take the performance index minimum​ That is, the angle of the six Hall signals, respectively, the angle of the rising and falling edges of the Hall sensors a, b, and c.

[0125] Assuming that the rising edge of the Hall sensor a is at the accurate position, the falling edge position is estimated

[0126]

[0127] Where, θ au is the angle of the rising edge of the Hall sensor a. The accurate falling edge position θ a is detected, and the zero error θ Δa of the Hall sensor a is calculated, as shown in Figure 7 .

[0128] Assuming that the rising edge of the Hall sensor a is at the accurate position, the rising edge position of the Hall sensor b is estimated as :

[0129]

[0130] There is an orthogonal error ΔΘ between the two Hall sensors a and b, as shown in Figure 8 :

[0131]

[0132] 1. Analysis of simulation results of open-loop estimation

[0133] The simulation framework for verifying the reliability of the sector position error identification method based on the sector position fault-tolerant operation method is shown in Figure 9 . Taking the Hall motor driven by the zero-order closed-loop algorithm as an example, without the "preprocessing" link, it directly works in the normal working state to identify the sector position error under different speed command signals.

[0134] 1) Comparison of step dynamic estimation results

[0135] The input step speed reference value is a constant 1000 r / min, and the zero-order closed-loop algorithm is used for starting operation under no load. The estimation results of the rotor information by the average speed method, the average acceleration method, and the fault-tolerant operation method of the present application with (without) sector position error correction link are compared, as shown in Figure 10 , Figure 11 and Figure 12 . The Hall sector position error exists: the Hb Hall sensor is deviated counterclockwise by 0.8 rad, and the Hc Hall sensor is deviated counterclockwise by 0.3 rad.

[0136] 2) Triangular wave dynamic estimation result comparison

[0137] The input speed reference value is set to be superimposed by a direct current component and a triangular wave component, the direct current component is 1300 r / min, the amplitude of the triangular wave component is 700 r / min, the frequency is 2.5 Hz, the Hb Hall sensor is counterclockwise deviated by 0.8 rad, the Hc Hall sensor is counterclockwise deviated by 0.3 rad, and the zero-order closed loop algorithm is used for no-load starting operation. At this time, the rotor information estimation results of the direct starting sector position error fault tolerance operation method in the presence (absence) of sector position error are as shown in the curve of FIG. 6. Figure 13

[0138] As shown in FIG. 6, Figure 13 It can be known that the direct starting sector position error fault tolerance operation method can directly control the motor starting without a "preprocessing" process, and has a certain tracking ability for the given speed. Since the multi-Hall sensor rotor information estimation system is degraded to a single-Hall sensor rotor information estimation system, the estimation lag time of the rotor information is increased, and the performance is reduced in the dynamic process. Therefore, in order to improve the dynamic performance of the motor control, the accurate Hall sector angle needs to be identified while the motor is starting and operating, and on this basis, the rotor information estimation method is switched to the average speed method and the average acceleration method, so as to reduce the estimation lag time of the rotor information.

[0139] 3) No-load step dynamic sector angle estimation result

[0140] The input step speed reference value is a constant 1000 r / min, the Hb Hall sensor is counterclockwise deviated by 0.8 rad, the Hc Hall sensor is counterclockwise deviated by 0.3 rad, and the zero-order closed loop algorithm is used for no-load starting operation. At this time, the angle value of the sector IV is 0.747 rad, and the curve shown in FIG. 7 is the estimated value of the angle of the sector IV. Figure 14

[0141] As shown in FIG. 7, Figure 14 It can be known that when the motor is in a dynamic operation state, the error of the instantaneous estimated value of the Hall sector angle is large, and as the motor continues to operate, the estimated value of the sector angle will gradually converge to the actual value, and the estimation accuracy is very high, and a more accurate Hall sector error can be obtained. The simulation results prove that the identification of the Hall sector position error by the method does not need to be realized through "preprocessing", and the sector position error can be accurately identified while the permanent magnet synchronous motor with the Hall sector position error is fault-tolerant controlled and operated, which provides sufficient preparation and premise for switching to the algorithm with more excellent estimation performance but needing the accurate Hall sector angle.

[0142] 4) Periodic dynamic sector angle estimation result

[0143] ​​The input speed reference value is set to be the superposition of the DC component and the triangular wave component. The DC component is 1300r / min, the amplitude of the triangular wave component is 700r / min, the frequency is 25Hz, and the Hb Hall sensor is deflected 0.8rad counterclockwise, the Hc Hall sensor is deflected 0.3rad counterclockwise, and the zero-order closed-loop algorithm is used for no-load start. At this time, the angle value of sector IV is 0.747rad. Figure 15 The curve shown in (a) is the angle estimation value of sector IV. The input speed reference value is set to be the superposition of the sinusoidal component and the DC component with the same frequency and amplitude. Figure 15 The curve shown in (b) is the angle estimate for sector IV.

[0144] right Figure 15 Sector IV angle estimation value obtained by sampling within 0.05s to 0.3s Find the average:

[0145]

[0146] Where m is the number of data points used to estimate the angle of sector IV.

[0147] It can be seen that although this method cannot directly obtain a more accurate sector angle during dynamic processes such as motor operation and acceleration and deceleration, a more accurate sector angle can be obtained by averaging the sector angle over a period of time. This simulation result proves the feasibility of this method in the dynamic operation of the motor.

[0148] 5) Load step dynamic sector angle estimation results

[0149] Input a step speed reference value, the speed reference value is a constant value of 1000r / min, and in 0.2s the load suddenly changes from no-load to 30N·m, and the Hb Hall sensor deflects 0.8rad counterclockwise, and the Hc Hall sensor deflects 0.3rad counterclockwise. Use the zero-order closed-loop algorithm to start the operation with no-load. At this time, the angle value of sector IV is 0.747rad. Figure 16 The curve shown in is the angle estimate for sector IV.

[0150] Depend on Figure 16 It can be seen that when the load suddenly changes, the Hall effect sector angle estimation will have an angle error in a short period of time, which is similar to the dynamic operation conditions such as motor acceleration and deceleration. Using formula (14), the angle estimation values ​​of sector IV in the period around the sudden load change are averaged. The angle estimation values ​​within 0.015s to 0.3s are used as an example for calculation. The estimated results are almost the same as the actual results. That is, it is believed that within a certain error range, this method is capable of estimating the sector angle under sudden load changes.

[0151] 2. Verification of sector position error tolerance operation method

[0152] The speed reference value of the input step is a constant 2000r / min, the no-load starting operation sector position error fault-tolerant operation method is verified, and the Hb Hall sensor is deviated counterclockwise by 0.8 rad, the Hc Hall sensor is deviated counterclockwise by 0.3 rad, driving is performed by using the sector position error fault-tolerant operation method, and the rotor actual information is compared with the method of driving by using the average speed method and the photoelectric encoder under the same working condition, wherein the closed-loop operation result of using the photoelectric encoder is as shown in Figure 17 The closed-loop operation result of using the fault-tolerant operation method is as shown in Figure 17 The closed-loop operation result of using the average speed method is as shown in Figure 19 .

[0153] It can be known from Figure 17 , Figure 18 that the sector position error can be approximately completely suppressed by using the fault-tolerant operation method for closed-loop control of the motor, although a certain dynamic performance reduction is caused by the estimated hysteresis in the fault-tolerant operation stage, but the performance is still very good, especially when the motor is operated at high speed, the estimated hysteresis of the fault-tolerant operation method will be significantly reduced.

[0154] It can be known from Figure 17 , Figure 19 that in the existing method, even if the most conservative average speed method is used, when the Hall sector position error exists, the performance reduction is still very obvious. It can be known from Figure 19 (b) that the speed dynamic process is significantly affected, and the speed tracking performance is reduced; it can be known from Figure 19 (c) that the torque instability is enhanced in the dynamic process, which will bring greater mechanical vibration to the load, and even damage the system, and the torque contains more harmonics in the steady-state process, which reduces the motor driving performance; it can be known from Figure 19 (d) that the Hall sector position error will generate more harmonics in the phase current, which will increase the motor loss, reduce the motor efficiency, increase the motor temperature rise, vibration and the like.

[0155] It can be known from Figure 17 and Figure 18 that the sector position error fault-tolerant operation method proposed in the application has great fault-tolerant performance for the Hall sector position error, and can realize that the closed-loop driving rotor actual position and speed are almost not affected by the sector position error when the sector position error exists. The method greatly improves the adaptability of the low-resolution Hall sensor in the case of large-scale application in the low-end scene, has great performance improvement in actual production and life, and is beneficial to the further popularization of the motor.

[0156] Through simulation verification, it is proved that the application has reliability, superiority and high practical value in the actual system.

Claims

1. A fault-tolerant operation method for a Hall sensor permanent magnet synchronous motor capable of direct start, characterized in that The method comprises the following steps: Step 1: Degenerate the multi-Hall sensor rotor information estimation system composed of r Hall sensors with sector position error into a system composed of one Hall sensor. For each rising or falling edge of the Hall sensor, the rotor can only output one valid Hall signal after one electrical cycle. The position between the two Hall signals is regarded as a generalized sector. The arc of the sector is not affected by the sector position error and is always radian; Step 2: The rising edge or falling edge of each Hall sensor uses a zero-order closed-loop algorithm to estimate the rotor information in a narrow sector adjacent to its sector edge; Step 3: Improve the original Hall signal processing method. According to the output of the Hall sensor rotor information estimation system in different Hall sectors, the different Hall sectors are numbered and output. After detecting the rising or falling edge, the current Hall sector number is accurately output. On this basis, fault-tolerant operation is performed. The specific steps are as follows: Step 31. For Sector edge, from the moment the rotor passes the previous Hall sector From the edge of the sector, the rotor information estimate is obtained based on the information of the past electrical cycle, which is used to estimate The information of the rotor in the Hall sector after the sector edge, is the rising edge of Hall sensor a, is the falling edge of Hall sensor a; and so on, the estimated value of the rotor information in each Hall sector in the current electrical cycle is obtained based on the information of the initial sector edge of the Hall sector in the past electrical cycle; Based on this step, direct starting of a permanent magnet synchronous motor with Hall sector position error is achieved; Step 32: When entering the next Hall sector from the current Hall sector, the angle of the current Hall sector is calculated by the following formula: ； in, is the time it takes for the rotor to rotate through the current Hall sector, is the estimated speed of the rotor in the current Hall sector; Based on this step, the Hall sector position error is identified to achieve higher performance fault-tolerant operation; Step 3. Calculate the average value of historical data to make the sector angle estimate gradually converge to the actual value: ； in, is the number of data points of the historical data obtained; Step 3 and 4: For the multi-Hall sensor rotor information estimation system composed of r Hall sensors, use 2r Hall signals with quantization errors through the least squares method to achieve uniform rotation of the motor, and correct the zero position error and orthogonal error of the Hall sensor.

2. The fault-tolerant operation method of a Hall sensor permanent magnet synchronous motor capable of direct start according to claim 1, characterized in that The specific steps of step 2 are as follows: Step 2.1: From the zero-order open-loop algorithm, i.e. the average speed method, we know that the current sector rotor speed is Use the average speed of the previous sector Estimate: Where, is the average speed of the rotor in the previous Hall sector, is the position where the rotor leaves the previous Hall sector, is the position where the rotor enters the previous Hall sector, The time it takes for the rotor to rotate through the previous Hall sector; Step 2: The rotor position estimation result is obtained by integrating the speed: Where, is the time the rotor is in the current Hall sector; is the moment when the rotor enters the current Hall sector; is the current estimated position of the rotor; is the starting position of the current Hall sector; Step 2 and 3: When the rotor rotates to the beginning of the current Hall sector, the deviation between the estimated rotor position deviation and the actual value in the previous Hall sector is: ； Where, The deviation between the estimated position of the rotor in the previous Hall sector time and the actual position; Step 24: Estimate the rotor speed deviation in the previous sector based on the rotor position estimation deviation: ； Where, is the average estimated speed error of the rotor in the previous Hall sector; The time it takes for the rotor to rotate through the previous Hall sector; Step 25: Based on the closed-loop feedback framework, the current sector rotor speed is estimated as: ； Where, is the estimated speed of the rotor in the current Hall sector; is the estimated average speed of the rotor in the previous Hall sector; Rewrite the above formula as: ； Then in the current sector Rotor position at moment The estimate is: ； Where, The starting position of the current sector.

3. The fault-tolerant operation method of a Hall sensor permanent magnet synchronous motor capable of direct start according to claim 1, characterized in that The specific steps of steps three and four are as follows: Step 341: Degenerate the multi-Hall sensor rotor information estimation system composed of r Hall sensors into a system with only one Hall sensor. Use only one Hall sensor to estimate the rotor's angular velocity, angular acceleration, and position. Under the detection of a single Hall sensor, quasi-uniform rotation is achieved. ； in, It is the period of detecting two consecutive rising edges or falling edges of any Hall sensor; is the previous cycle time; Step 342: Use the least squares method to get the motor rotation Zhou's income The Hall signal is used to estimate the time it takes for the motor to rotate one circle : ； Step 343: Get performance indicators smallest , That is the time it takes for the motor to rotate one circle, so the angular velocity of the motor is uniform The estimate is: ； Step 344: Use the least squares method to Hall signal Simultaneous estimation: ； ； in, Indicates that along the direction of motor rotation, from A Hall signal to the The time it takes for a Hall signal to , take the performance index smallest , is the vector composed of the angles of the Hall signal, which is obtained by detecting the rising and falling edges of the Hall signal; Step 3, 4, and 5: Assuming the rising edge of Hall sensor a is at the correct position, estimate the falling edge position. : ； in, is the expected angle of the rising edge of Hall sensor a; Detect the exact falling edge position , calculate the zero position error of Hall sensor a : ； in, is the expected angle of the falling edge of Hall sensor a; Assuming that the rising edge of Hall sensor a is at the correct position, the rising edge position of Hall sensor b is The estimate is: ； There is an orthogonality error between the two Hall sensors a and b : ； in, is the expected angle of the rising edge of Hall sensor b; The zero position error and quadrature error of each Hall sensor obtained by identification are stored in the software, and correction is made when calculating the detected Hall signal, that is, the online correction of the Hall sector position error is realized.

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