Fault-tolerant operation method of Hall sensor permanent magnet synchronous motor capable of being directly started

Abstract

The invention discloses a fault-tolerant operation method of a Hall sensor permanent magnet synchronous motor capable of being directly started, which comprises the following steps of: degenerating a multi-Hall sensor rotor information estimation system with sector position errors into a system consisting of one Hall sensor; only one effective Hall signal can be output after the rotor rotates for one electric cycle, and the position between the two Hall signals is regarded as a generalized sector; the rising edge or the falling edge of each single Hall sensor adopts a zero-order closed-loop algorithm to estimate rotor information in a narrow sector adjacent to the sector edge of the single Hall sensor; different Hall sectors are numbered and output according to the output of a Hall sensor rotor information estimation system, after a rising edge or a falling edge is detected, the number of the current entering Hall sector is accurately output, and fault-tolerant operation is performed on the basis. According to the method, the motor can be directly driven to operate in an actual working state, and continuous and high-cost-performance operation of the Hall motor is facilitated.

Description

Technical Field

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

[0002] The existing fault-tolerant operation method for sector position errors usually first identifies the sector position error, compensates and corrects it in software, and then realizes sector position error fault-tolerant operation on this basis. Some scholars have also proposed a method of estimating the Hall signal position through interpolation, which can realize sector position error fault-tolerant control and operation when the Hall sector position has errors.

[0003] Among them, the offline correction method is the most widely used in production and life: in the offline state, such as before the Hall motor system leaves the factory, the shaft of the corrected motor is manually rotated or the corrected motor is dragged by an external prime mover to rotate, usually at a uniform speed, and the phase difference between the Hall signal and the back electromotive force zero-crossing point is observed. After that, the phase difference is compensated in the software to achieve the coincidence of the Hall signal and the back electromotive force zero-crossing point. Due to the characteristics of low efficiency and the inability to rely on its own motor, the offline method cannot support the large-scale popularization of permanent magnet synchronous motors based on low-resolution Hall sensors in low-end scenarios. At the same time, it is not applicable in scenarios where low-resolution Hall sensors are prone to time-varying position offsets, because it cannot identify, correct, fault-tolerantly control and operate the position error offset after the sector position error correction.

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

[0005] If online operation is defined as the normal operation of the motor according to the given instructions, then offline operation means the opposite. The above offline correction method and online correction method are both 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 Hall motors that are prone to sector position errors, and cannot support the application of Hall motors in high-end occasions and extreme environments; in addition, the current driving method of permanent magnet synchronous motors based on low-resolution Hall sensors does not pay attention to the Hall sector number when processing Hall signals, that is, through XOR operations, the Hall signal is converted into a square wave with the Hall sector as the period, and only determines whether the rotor enters the next sector from the current sector, such as Figure 1This processing simplifies the processing of Hall signals, but at the same time reduces the degree of freedom of Hall signal processing, making it difficult to make more dimensional estimates and drive controls based on Hall signals. Summary of the invention

[0006] The present invention analyzes the existing sector position error fault-tolerant operation method and sector position error correction method, and based on a full study of offline methods and online methods, provides a Hall sensor permanent magnet synchronous motor fault-tolerant operation method that can be directly started based on the permanent magnet synchronous motor control strategy based on the Hall sector position error closed-loop feedback. This method implements the permanent magnet synchronous motor control strategy based on the Hall sector position error closed-loop feedback and online sector position error correction and fault-tolerant operation without "preprocessing", which can directly drive the motor to operate in the actual working state, is conducive to the continuous and cost-effective operation of the Hall motor, and strongly supports the mass production and application of the Hall motor in low-end scenarios.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] A fault-tolerant operation method of a Hall sensor permanent magnet synchronous motor capable of direct starting, comprising the following steps:

[0009] 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 edge 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 radian of the sector is not affected by the sector position error and is always 2π radians.

[0010] 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. The specific steps are as follows:

[0011] Step 21: From the zero-order open-loop algorithm, i.e. the average speed method, we know that the current sector rotor speed Use the average speed v of the previous sector β Estimate:

[0012]

[0013] In the formula, v β 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 of the rotor entering the previous Hall sector, T βi It is the time taken by the rotor to rotate through the previous Hall sector;

[0014] Step 22: The rotor position estimation result is obtained by integrating the speed:

[0015]

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

[0017] Step 2: 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:

[0018]

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

[0020] Step 24: Estimate the rotor speed deviation in the previous sector from the rotor position estimation deviation:

[0021]

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

[0023] Step 25: Based on the closed-loop feedback framework, the current sector rotor speed is estimated as:

[0024]

[0025] In the formula, 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;

[0026] Rewrite the above formula as:

[0027]

[0028] Then the current sector t k Rotor position at time The estimate is:

[0029]

[0030] In the formula, x sis the starting position of the current sector;

[0031] Step 3: Improve the original Hall signal processing method, and output the different Hall sectors according to the output of the multi-Hall sensor rotor information estimation system in different Hall sectors. After detecting the rising edge or falling edge, accurately output the current Hall sector number, and perform fault-tolerant operation on this basis. The specific steps are as follows:

[0032] Step 31: For h a + sector edge, since the rotor rotates past the previous Hall sector h a + Sector edge, based on the information of the past electrical cycle, the rotor information estimate is obtained to estimate h a +The information of the rotor in the Hall sector after the sector edge, h a + is the rising edge of Hall sensor a, h 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;

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

[0034] 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:

[0035]

[0036] Among them, T ki It is the time taken by the rotor to rotate through the current Hall sector;

[0037] Based on this step, the Hall sector position error is identified to achieve higher performance fault-tolerant operation;

[0038] Step 3. Calculate the average value of historical data to make the estimated sector angle gradually converge to the actual value:

[0039]

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

[0041] Step 3 and 4: For the multi-Hall sensor rotor information estimation system composed of r Hall sensors, 2r Hall signals with quantization errors are used to realize the uniform rotation of the motor through the least square method, and the zero position 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, and estimate the rotor motion angular velocity, angular acceleration and position by only one Hall sensor. Under the detection of a single Hall sensor, quasi-uniform rotation is achieved, and:

[0043] T j ≈T j-1 ;

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

[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. The angular velocity of the motor is The estimate is:

[0048]

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

[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, which is used to make the performance index Smallest is a vector composed of the angles of the Hall signal, obtained by detecting the rising and falling edges of the Hall signal;

[0052] Step 3, 4, 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] Detect the exact falling edge position Calculate the zero position error θ of Hall sensor a Δa :

[0056]

[0057] Among them, 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 correct position, the rising edge position of Hall sensor b The estimate is:

[0059]

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

[0061]

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

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

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

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

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

[0067] Figure 1 This is a schematic diagram of performing XOR operation on Hall signal;

[0068] Figure 2 A schematic diagram of the Hall sector division without sector position error;

[0069] Figure 3 Schematic diagram of Hall sector division with sector position error;

[0070] Figure 4 This is a schematic diagram of the sector numbering output by the Hall signal;

[0071] Figure 5 It is a schematic diagram of the combined system estimation method;

[0072] Figure 6 This is a schematic diagram of the quantization error of the Hall sensor;

[0073] Figure 7 This is a schematic diagram of the zero position error of Hall sensor a;

[0074] Figure 8 Schematic diagram of orthogonal error between two Hall sensors a and b;

[0075] Fig. 9 It is a schematic diagram of sector position error identification;

[0076] Fig.10 is the estimation result of the average speed method with (without) sector position error;

[0077] Fig.11 is the estimation result of the average acceleration method with (without) sector position error;

[0078] Fig.12 Estimation results of the fault-tolerant operation method with (without) sector position error;

[0079] Fig.13 Estimation results of the fault-tolerant operation method with (without) sector position error;

[0080] Fig.14 is the estimation of the angle of sector IV at step speed;

[0081] Fig.15 is the angle estimate of sector IV at triangular wave speed;

[0082] Fig.16 It is the angle estimation of sector IV when the load changes suddenly due to step speed;

[0083] Fig.17 The result of closed-loop operation using a photoelectric encoder when there is sector position error;

[0084] Fig.18 The closed-loop operation result using the fault-tolerant operation method when there is a sector position error;

[0085] Fig.19 This is the closed-loop operation result using the average speed method when there is sector position error;

[0086] In the figure, Tβi It is the time taken by 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; 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 between the estimated position and 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 solution of the present invention is further described below in conjunction with the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0088] The present invention provides a fault-tolerant operation method for a Hall sensor permanent magnet synchronous motor capable of direct start. The method 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 orthogonal error and zero position error. When there is no Hall sector position error, the sector division is as follows Figure 2 When the discrete Hall sensors Ha, Hb, and Hc all have zero position errors and there are orthogonal errors between the three, the Hall sector division is as follows: Figure 3 At this time, although six Hall signals at fixed angles will be detected every time the motor rotates one circle, the absolute electrical angle positions of the six Hall signals and the relative electrical angle phase differences between them are unknown, and the sector angle can no longer be used to estimate the rotor position and speed information.

[0089] Although the absolute electrical angle positions of the six Hall signals in each electrical cycle and the relative electrical angle phase differences between them are unknown when there is a sector position error, the electrical angle phase difference between the same Hall signals in multiple electrical cycles is always a constant, which is 2π radians per electrical cycle. That is, the multi-Hall sensor rotor information estimation system can be degenerated into a single Hall sensor rotor information estimation system. 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 radian of the sector is not affected by sector position errors such as discrete Hall sensor installation errors and zero position errors, and is always 2π radians.

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

[0091] When the rotor rotates to the beginning of the current sector, the estimated value of the rotor position in the previous sector Deviation from the actual value Δx ki-1 for:

[0092]

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

[0094]

[0095] Among them, T βi It is the time taken by the rotor to rotate through the previous sector;

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

[0097]

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

[0099]

[0100] Then the current sector t k The rotor position at this moment is estimated as:

[0101]

[0102] Among them, x s is the starting position of the current Hall sector;

[0103] In order to reduce the estimation hysteresis, the multi-Hall sensor rotor information estimation system with sector position error is regarded as a system composed of one Hall sensor. The rising or falling edge of each Hall sensor estimates the rotor information in a narrow sector adjacent to its sector edge.

[0104] The original Hall signal processing method is improved. The original Hall signal processing method does not distinguish between sectors. The three Hall signals are XORed to make the output a rectangular wave. When the rising edge or the falling edge is detected, it is determined that the rotor enters the next sector. Figure 3Now 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 edge or falling edge, it is necessary to accurately output the current sector number, and perform fault-tolerant operation on this basis. Figure 4 shown.

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

[0106] In order to further reduce the estimation lag time and improve the dynamic performance of the motor, it is necessary to switch the rotor information estimation method to the average speed method and average acceleration method after effectively identifying the Hall sector angle. The motor operating performance using these methods is highly dependent on the accurate Hall sector angle. Therefore, it is necessary to identify the Hall sector angle with high accuracy while directly starting and running with Hall sector position error tolerance to support the use of 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 estimated speed value of the motor during the dynamic process of acceleration and deceleration is The actual speed v k There is a large deviation, which causes the estimated sector angle to have a large deviation from the actual value, but it can still be used under certain circumstances. The historical data can be averaged 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] In order to obtain a more accurate sector angle, the motor needs to run at a steady speed. The influence of the counter quantization error needs to be considered at the same time. That is, due to the existence of the counting quantization error, the counting accuracy will affect the detection of the Hall signal. In one electrical cycle, six Hall signals will be randomly generated within a certain range. This makes it difficult to rely on a single Hall signal to make the motor rotate at a uniform speed, especially when the timer division coefficient is low, which will produce a large error, such as Figure 6 shown.

[0114] Six Hall signals with quantization errors can be used to achieve uniform rotation of the motor through the least square method, and the zero position error and orthogonal error of the Hall sensor can be corrected.

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

[0116] T j ≈T j-1 (8)

[0117] Among them, T j To detect the period of two consecutive rising or falling edges of any Hall sensor, T j-1 The time of the previous cycle.

[0118] The least square method is used to take the 6N Hall signals obtained by the motor rotating N times to estimate the time it takes for the motor to rotate one circle.

[0119]

[0120] Take performance indicators The smallest T k , T k That is, the time it takes for the motor to rotate one circle. The angular velocity of the motor is The estimate is:

[0121]

[0122] The least square method is used to calculate the six Hall signals Simultaneous estimates:

[0123]

[0124] Among them, T ij (i=1,2,...,6,j=1,2,...,6) represents the time taken from the i-th Hall signal to the j-th Hall signal along the direction of motor rotation. Smallest That is, the angles of the six Hall signals, which are the angles of the rising and falling edges of Hall sensors a, b, and c respectively.

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

[0126]

[0127] Among them, θ au is the angle of the rising edge of Hall sensor a. The exact falling edge position θ is detected a , calculate the zero position error θ of Hall sensor a Δa ,like Figure 7 shown.

[0128] Assuming that the rising edge of Hall sensor a is at the correct position, the rising edge position of Hall sensor b The estimate is:

[0129]

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

[0131]

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

[0133] The reliability of the sector position error identification method based on the sector position fault-tolerant operation method is simulated and verified. The simulation framework is as follows: Fig. 9 Taking the zero-order closed-loop algorithm driving the Hall motor as an example, without going through the "pre-processing" link, it directly works in the normal working state to realize the identification of the sector position error under different speed command signals.

[0134] 1) Comparison of step dynamic estimation results

[0135] Input a step speed reference value, the speed reference value is a constant value of 1000r / min, and use a zero-order closed-loop algorithm to start the operation without load. Compare the estimation results of the rotor information using the average speed method, the average acceleration method and the fault-tolerant operation method of the present invention when there is (or is not) a sector position error without a sector position error correction link. Fig.10 , Fig.11 and Fig.12 As shown in the figure, there is a situation where the Hall sector position error exists: the Hb Hall sensor deflects 0.8 rad counterclockwise, and the Hc Hall sensor deflects 0.3 rad counterclockwise.

[0136] 2) Comparison of triangle wave dynamic estimation results

[0137] 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 2.5Hz, and the Hb Hall sensor is deflected 0.8rad counterclockwise, and the Hc Hall sensor is deflected 0.3rad counterclockwise. The zero-order closed-loop algorithm is used for no-load start operation. At this time, the direct start sector position error fault-tolerant operation method is used to estimate the rotor information when there is (or is not) a sector position error. Fig.13 shown.

[0138] Depend on Fig.13 It can be seen that the direct start sector position error tolerance operation method is used to control the motor operation. It can directly control the motor start without the need for a "preprocessing" process, and has a certain tracking capability for a 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 motor control, it is necessary to identify the accurate Hall sector angle while the motor is starting and running, and on this basis, the estimation method of the rotor information is switched to the average speed method and the average acceleration method to reduce the estimation lag time of the rotor information.

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

[0140] Input the step speed reference value, the speed reference value is the constant value 1000r / min, 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 operation. At this time, the angle value of sector IV is 0.747rad, Fig.14 The curve shown in is the angle estimate for sector IV.

[0141] Depend on Fig.14 It can be seen that when the motor is in a dynamic operation state, the error of the instantaneous estimated value of the Hall sector angle is large. As the motor continues to run, the estimated value of the sector angle will gradually converge to the vicinity of the actual value, and the estimation accuracy is very high. Based on this, a more accurate Hall sector error can be obtained. The simulation results show that the identification of the Hall sector position error by the method of the present invention does not require "preprocessing". It can accurately identify the sector position error while performing fault-tolerant control and operation of the permanent magnet synchronous motor with Hall sector position error. This provides sufficient preparation and premise for switching to an algorithm with better estimation performance but requiring accurate Hall sector angles.

[0142] 4) Periodic dynamic sector angle estimation results

[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 operation start. At this time, the angle value of sector IV is 0.747rad, Fig.15 The curve shown in (a) is the estimated angle 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. Fig.15 The curve shown in (b) is the angle estimate for sector IV.

[0144] right Fig.15 Sector IV angle estimation 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 dynamic motor operation.

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

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

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

[0151] 2. Sector Position Error Tolerant Operation Method Verification

[0152] Input the speed reference value of the step, the speed reference value is the constant value of 2000r / min, and verify the sector position error fault tolerance operation method of no-load start operation. The Hb Hall sensor is deflected 0.8rad counterclockwise, and the Hc Hall sensor is deflected 0.3rad counterclockwise. The sector position error fault tolerance operation method is used for driving, and the actual information of the rotor is compared with the average speed method and the photoelectric encoder drive method under the same working conditions. The closed-loop operation results using the photoelectric encoder are as follows Fig.17 As shown in the figure, the closed-loop operation results using the fault-tolerant operation method are as follows Fig.17 As shown in the figure, the closed-loop operation results using the average speed method are as follows Fig.19 shown.

[0153] Compare Fig.17 , Fig.18 It can be seen that the sector position error can be almost completely suppressed by using the fault-tolerant operation method to control the motor in a closed loop. Although the estimated hysteresis will lead to a certain reduction in dynamic performance during the fault-tolerant operation stage, its performance is still very impressive, especially when the motor is running at high speed, the estimated hysteresis of the fault-tolerant operation method will be significantly reduced.

[0154] Compare Fig.17 , Fig.19 It can be seen that in the existing methods, even if the most conservative average velocity method is used, when there is a Hall sector position error, its performance is still significantly reduced. Fig.19 (b) It can be seen that the speed dynamic process is significantly affected, and the tracking performance for a given speed is reduced; Fig.19 (c) It can be seen that the torque instability increases in the dynamic process, which will bring about greater mechanical vibration of the load and even damage the system. In the steady-state process, the torque contains more harmonics, which reduces the drag performance of the motor. Fig.19 (d) It can be seen that the Hall sector position error will generate more harmonics in the phase current, which will increase motor losses, reduce motor efficiency, increase motor temperature rise, vibration, etc.

[0155] Depend on Fig.17 and Fig.18 It can be seen that the sector position estimation fault-tolerant operation method proposed in the present invention has great fault tolerance performance for Hall sector position errors, and can achieve closed-loop drive when there are sector position errors. The actual position and speed of the rotor are almost unaffected by the sector position error. This method greatly improves the adaptability of low-resolution Hall sensors in large-scale applications in low-end scenarios, has a significant performance improvement in actual production and life, and is conducive to the further popularization of this type of motor.

[0156] The simulation results show that the present invention has high reliability, superiority and practical value in practical systems.

Claims

1. A fault-tolerant operation method for a Hall sensor permanent magnet synchronous motor capable of direct starting, 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 edge 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 radian of the sector is not affected by the sector position error and is always 2π radians. 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 the sector edge; Step 3: Improve the original Hall signal processing method, number and output different Hall sectors according to the output of the Hall sensor rotor information estimation system in different Hall sectors, accurately output the current Hall sector number after detecting the rising edge or falling edge, and perform fault-tolerant operation on this basis.

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 21: From the zero-order open-loop algorithm, i.e. the average speed method, we know that the current sector rotor speed Use the average speed v of the previous sector β Estimate: In the formula, v β 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 of the rotor entering the previous Hall sector, T βi It is the time taken by the rotor to rotate through the previous Hall sector; Step 22: The rotor position estimation result is obtained by integrating the speed: In the formula, t k is the time the rotor is in the current Hall sector; t s is the moment when the rotor enters the current Hall sector; is the estimated current position of the rotor; x s is the starting position of the current Hall sector; Step 2: 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: In the formula, Δx ki-1 The deviation between the estimated position of the rotor in the previous Hall sector time and the actual position; is the estimated position of the rotor in the previous Hall sector time; Step 24: Estimate the rotor speed deviation in the previous sector from the rotor position estimation deviation: In the formula, Δv k is the average estimated speed error of the rotor in the previous Hall sector; T βi It is the time taken by 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: In the formula, 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 the current sector t k Rotor position at time The estimate is: In the formula, x s 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 step three are as follows: Step 31: For h a + sector edge, since the rotor rotates past the previous Hall sector h a + Sector edge, based on the information of the past electrical cycle, the rotor information estimate is obtained to estimate h a +The information of the rotor in the Hall sector after the sector edge, h a + is the rising edge of Hall sensor a, h 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: Among them, T ki It is the time taken by the rotor to rotate through 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 estimated sector angle gradually converge to the actual value: Where p is the number of data points of historical data taken; Step 3 and 4: For the multi-Hall sensor rotor information estimation system composed of r Hall sensors, 2r Hall signals with quantization errors are used to achieve uniform rotation of the motor through the least squares method, and the zero position error and orthogonal error of the Hall sensor are corrected.

4. The fault-tolerant operation method of a Hall sensor permanent magnet synchronous motor capable of direct start according to claim 3 is 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, and estimate the rotor motion angular velocity, angular acceleration and position by only one Hall sensor. Under the detection of a single Hall sensor, quasi-uniform rotation is achieved, and: T j ≈T j-1 ; Among them, T j It is the period of detecting two consecutive rising edges or falling edges of any Hall sensor; T j-1 is the previous cycle time; 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 time. Step 343: Get performance indicators The smallest T k , T k That is, the time it takes for the motor to rotate one circle. The angular velocity of the motor is The estimate is: Step 344: Use the least squares method to calculate 2rN Hall signals Simultaneous estimates: 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, which is used to make the performance index Smallest is a vector composed of the angles of the Hall signal, obtained by detecting the rising and falling edges of the Hall signal; Step 3, 4, 5: Assuming the rising edge of Hall sensor a is at the correct position, estimate the falling edge position Among them, θ au is the expected angle of the rising edge of Hall sensor a; Detect the exact falling edge position Calculate the zero position error θ of Hall sensor a Δa : Among them, θ ad 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 The estimate is: There is an orthogonal error Δθ between the two Hall sensors a and b: Among them, θ bu is the expected angle of the rising edge of Hall sensor b; The zero position error and orthogonal error of each Hall sensor obtained by identification are stored in the software, and correction is performed when calculating the detected Hall signal, that is, the online correction of the Hall sector position error is realized.

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