Compensation method for installation error of Hall sensor in permanent magnet synchronous motor

Abstract

The invention discloses a method for compensating the installation error of the Hall sensor in a permanent magnet synchronous motor, comprising: firstly, using a constant voltage-frequency ratio control method to put the motor in a uniform speed operation state, and then dividing one cycle into six sectors through six rotor positions detected by the Hall sensor, and calculating an absolute reference position through a controller to correct the absolute deviation of three Hall sensors. The compensation amount is found through the obtained absolute deviation, thereby indicating the actual position of the rotor, and reflecting all the information of the absolute error by selecting three consecutive sectors, expressing the complete absolute position deviation correction equation by establishing a minimum variance estimation, and measuring the corresponding time by a timer of the controller to calculate the relative position deviation, thereby performing position compensation. This method can reduce the harmonic content of the current, improve the sinusoidality, accurately obtain the actual position of the rotor, and improve the sinusoidality of the current.

Description

Technical Field

[0001] The invention relates to the technical field of permanent magnet synchronous motors, and in particular to a method for compensating installation errors of Hall sensors in permanent magnet synchronous motors. Background Art

[0002] Permanent magnet synchronous motor control systems have broadened many fields and can now achieve high-precision, fast response, high stability and high-efficiency energy-saving motion control. Hall sensors are divided into linear Hall sensors and switch Hall sensors. Linear Hall sensors are composed of Hall elements, linear amplifiers and emitter followers, and they output analog quantities. Switch Hall sensors are composed of voltage regulators, Hall elements, differential amplifiers, Schmitt triggers and output stages, and they output digital quantities.

[0003] When there is a deviation in the position of the Hall sensor in the permanent magnet synchronous motor, and when the rotor position detected by the Hall sensor deviates from the ideal rotor position, it will have a more serious impact on the motor control, causing torque pulsation and current distortion, and in severe cases, burning the motor. Summary of the invention

[0004] The object of the present invention is to provide a method for compensating the installation error of a Hall sensor of a permanent magnet synchronous motor based on the least squares method, so as to solve the problem that there is a deviation in the initial installation position of the Hall position sensor of the permanent magnet synchronous motor in the prior art.

[0005] A method for compensating installation errors of a Hall sensor of a permanent magnet synchronous motor comprises the following steps:

[0006] Step 1: The permanent magnet synchronous motor first uses a constant voltage-frequency ratio control method to keep the motor in a uniform speed operation state;

[0007] Step 2, then divide one cycle into six sectors using the six rotor positions detected by the Hall sensor;

[0008] Step 3, calculating an absolute reference position through the controller to correct the absolute deviation of the three Hall sensors;

[0009] Step 4, by obtaining the absolute deviation of step 2, the compensation amount is found, thereby indicating the actual position of the rotor;

[0010] Step 5, by selecting three consecutive sectors to reflect all the information of the absolute error, and by establishing the minimum variance estimation of the absolute position deviation to express the complete absolute position deviation correction equation;

[0011] Step 6: The timer of the controller measures the corresponding time and calculates the relative position deviation of the Hall sensor, thereby obtaining a position compensation scheme for the Hall sensor, thereby performing position compensation for the Hall sensor.

[0012] Furthermore, in step 1, when the motor is running at a constant speed, one cycle is divided into six sectors by the six rotor positions detected by the Hall sensor, and the controller can detect the electrical angle corresponding to each sector. The specific calculation formula is:

[0013]

[0014] Among them, θ eH is the absolute position deviation of the Hall sensor, in degrees, θ is the electrical angle of each sector, θ=(θ I θ II θ III θ IV θ V θ VI ) T , the unit is degree, E = (1 1 1 1 1 1) T ,θ eH =(θ eHA θ eHB θ eHC ) T ,θ eHA is the absolute position deviation of Hall sensor A, in degrees, θ eHB is the absolute position deviation of Hall sensor B, in degrees, θ eHC is the absolute position deviation of the Hall sensor C, in degrees,

[0015] Furthermore, in step 2, when the motor is running at a uniform speed, the controller detects the corresponding electrical angle of each sector, thereby estimating the sum of the position deviations of two adjacent Hall sensors, that is, the absolute error; if the Hall signal at the beginning of the sector jumps early, the sector becomes wider; if the Hall signal at the beginning of the sector jumps late, the sector becomes narrower; the value of the Hall installation angle corresponding to the sector end signal minus 60° relative to the sector start signal is the relative error.

[0016] Furthermore, the compensation amount in step 3 is used to correct the absolute deviation of the Hall sensor, and the specific formula is as follows:

[0017]

[0018] Among them, θ eH is the absolute position deviation of the Hall sensor, in degrees, T is the time of each sector detected, T = (T I TII T III T IV T V T VI ) T , in milliseconds, T av is the average time of the detected sector, in milliseconds, E = (1 1 1 1 1 1) T .

[0019] Furthermore, in step 4, three consecutive sectors are selected to reflect all information of the absolute error.

[0020] Furthermore, in step 5, the first three sectors are selected to establish the existence estimation parameters The augmented equation of the absolute deviation and relative deviation is as follows:

[0021]

[0022] in, is the estimated value of the absolute position deviation of Hall sensor A in degrees, is the relative deviation between Hall sensor B and Hall sensor A, in degrees, is the relative deviation between Hall sensor C and Hall sensor B, in degrees.

[0023] Furthermore, in step 6, the relative position deviation of the Hall sensor is obtained by measuring the corresponding time through the timer of the controller, thereby expressing the absolute position deviation correction value of the Hall sensor. The specific formula is as follows:

[0024]

[0025] in, is the estimated value of the absolute position deviation of Hall sensor A in degrees, is the estimated value of the absolute position deviation of Hall sensor B in degrees, is the estimated value of the absolute position deviation of Hall sensor C in degrees, is the relative deviation between Hall sensor A and Hall sensor C, in degrees, is the relative deviation between Hall sensor B and Hall sensor A, in degrees, is the relative deviation between Hall sensor C and Hall sensor B, in degrees;

[0026] The three Hall sensors all have absolute position deviations during the installation process, which will cause the motor to fail to start normally. The estimated correction term of the Hall sensor absolute position deviation is to compensate for and correct the absolute position deviation of the Hall sensor during the installation process in actual operation. Therefore, during the control process, the time of the first three sectors is used for real-time calculation to obtain the estimated correction term of the Hall sensor absolute position deviation, as shown in the following formula:

[0027]

[0028] Among them, θ com is the estimated correction term for the absolute position deviation of the Hall sensor, in degrees, T i and T i-2 T is the detected sector time in milliseconds. av The average time of the detected sectors in milliseconds.

[0029] Beneficial effects of the present invention:

[0030] (1) After adopting the deviation correction method of the Hall sensor, the position deviation is small, and there is only an initial error, no position fluctuation, and the three-phase current sinusoidality is good;

[0031] (2) The harmonic content of the current is reduced, the sinusoidality is better, the rotor position deviation is reduced, the actual position of the rotor can be obtained more accurately, and the sinusoidality of the current is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a flowchart of a method for detecting installation errors of a Hall sensor in a permanent magnet synchronous motor specifically implemented by the present invention.

[0033] Figure 2 This is a diagram of sector detection results after Hall position deviation according to a specific implementation of the present invention.

[0034] Figure 3 This is a diagram of the position deviation results of a Hall sensor after least squares compensation according to a specific implementation of the present invention. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0036] The present invention provides a method for compensating installation errors of a permanent magnet synchronous motor Hall sensor based on the least squares method. Figure 1 As shown, the specific method includes the following steps:

[0037] Step S1: The permanent magnet synchronous motor firstly adopts a constant voltage ratio control method to keep the motor in a uniform speed operation state.

[0038] Step S2: Divide one cycle into six sectors using the six rotor positions detected by the Hall sensor.

[0039] like Figure 2 As shown in the figure, when the motor runs at a constant speed, the six rotor positions detected by the Hall sensor divide one cycle into six sectors. The controller can detect the electrical angle corresponding to each sector. The specific calculation formula is:

[0040]

[0041] Among them, θ eH is the absolute position deviation of the Hall sensor, in degrees, θ is the electrical angle of each sector, θ=(θ I θ II θ III θ IV θ V θ VI ) T , the unit is degree, E = (1 1 1 1 1 1) T ,θ eH =(θ eHA θ eHB θ eHC ) T ,θ eHA is the absolute position deviation of Hall sensor A, in degrees, θ eHB is the absolute position deviation of Hall sensor B, in degrees, θ eHC is the absolute position deviation of the Hall sensor C, in degrees,

[0042] Step S3: The controller calculates an absolute reference position to correct the absolute deviation of the three Hall sensors. The compensation amount in step S3 is used to correct the absolute deviation of the Hall sensors. The specific formula is as follows:

[0043]

[0044] Among them, θ eH is the absolute position deviation of the Hall sensor, in degrees, T is the time of each sector detected, T = (T I T II T III T IV T V T VI ) T , in milliseconds, T av is the average time of the detected sector in milliseconds, θ eH =(θ eHA θeHB θ eHC ) T ,θ eHA is the absolute position deviation of Hall sensor A, in degrees, θ eHB is the absolute position deviation of Hall sensor B, in degrees, θ eHC is the absolute position deviation of the Hall sensor C, in degrees, E=(1 1 1 1 1 1) T .

[0045] Step S4: By obtaining the absolute deviation of step S2, the compensation amount is found, thereby indicating the actual position of the rotor. In step S4, three consecutive sectors are selected to reflect all the information of the absolute error, which ensures the rapidity of the speed response in the motor to a certain extent, and reduces the position estimation error when there is a deviation in the position installation to a certain extent.

[0046] Step S5: Select three consecutive sectors to reflect all the information of the absolute error, and establish a minimum variance estimate of the absolute position deviation to express the complete absolute position deviation correction equation.

[0047] In step S5, the first three sectors are selected to establish the existence estimation parameters The augmented equation of the absolute deviation and relative deviation is as follows:

[0048]

[0049] in, is the estimated value of the absolute position deviation of Hall sensor A in degrees, is the relative deviation between Hall sensor B and Hall sensor A, in degrees, is the relative deviation between Hall sensor C and Hall sensor B, expressed in degrees, θ eHA is the absolute position deviation of Hall sensor A, in degrees, θ eHB is the absolute position deviation of Hall sensor B, in degrees, θ eHC is the absolute position deviation of the Hall sensor C, in degrees.

[0050] The relative position deviation of the Hall sensor can be obtained by measuring the corresponding time through the controller's timer, thereby expressing the absolute position deviation correction value of the Hall sensor. The specific formula is as follows:

[0051]

[0052] in, is the estimated value of the absolute position deviation of Hall sensor A in degrees, is the estimated value of the absolute position deviation of Hall sensor B in degrees, is the estimated value of the absolute position deviation of Hall sensor C in degrees, is the relative deviation between Hall sensor A and Hall sensor C, in degrees, is the relative deviation between Hall sensor B and Hall sensor A, in degrees, is the relative deviation between Hall sensor C and Hall sensor B, in degrees;

[0053] The three Hall sensors all have absolute position deviations during the installation process, which will cause the motor to fail to start normally. The estimated correction term of the Hall sensor absolute position deviation is to compensate for and correct the absolute position deviation of the Hall sensor during the installation process in actual operation. Therefore, during the control process, the time of the first three sectors is used for real-time calculation to obtain the estimated correction term of the Hall sensor absolute position deviation, as shown in the following formula:

[0054]

[0055] Among them, θ com is the estimated correction term for the absolute position deviation of the Hall sensor, in degrees, T i and T i-2 T is the detected sector time in milliseconds. av The average time of the detected sectors in milliseconds.

[0056] Step S6: The timer of the controller measures the corresponding time and calculates the relative position deviation of the Hall sensor, thereby obtaining a position compensation scheme for the Hall sensor, thereby performing position compensation for the Hall sensor.

[0057] The following is an embodiment:

[0058] like Figure 3 As shown, the specific process is as follows:

[0059] When T i 1ms, T i-1 2ms, T i-2 When it is 3ms, The figure shows the position deviation of the Hall sensor after compensation. The position deviation of the Hall sensor is significantly reduced, which proves the effectiveness of the method and the accuracy of control.

[0060] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed by the present invention should be included in the protection scope recorded in the claims.

Claims

1. A method for compensating installation error of a Hall sensor of a permanent magnet synchronous motor, characterized in that: The steps include: Step 1: The permanent magnet synchronous motor first uses a constant voltage-frequency ratio control method to keep the motor in a uniform speed operation state; Step 2, then divide one cycle into six sectors using the six rotor positions detected by the Hall sensor; In step 2, when the motor is running at a constant speed, the six rotor positions detected by the Hall sensor divide one cycle into six sectors, and the controller can detect the electrical angle corresponding to each sector. The specific calculation formula is: Among them, θ eH is the absolute position deviation of the Hall sensor, in degrees, θ is the electrical angle of each sector, θ=(θ I θ II θ III θ IV θ V θ VI ) T , the unit is degree, E = (1 1 1 1 1 1) T ,θ eH =(θ eHA θ eHB θ eHC ) T ,θ eHA is the absolute position deviation of Hall sensor A, in degrees, θ eHB is the absolute position deviation of Hall sensor B, in degrees, θ eHC is the absolute position deviation of the Hall sensor C, in degrees, In step 2, when the motor is running at a constant speed, the controller detects the corresponding electrical angle of each sector, thereby estimating the sum of the position deviations of two adjacent Hall sensors, that is, the absolute position deviation; if the Hall signal at the beginning of the sector jumps in advance, the sector becomes wider; if the Hall signal at the beginning of the sector jumps in a delayed manner, the sector becomes narrower; Step 3, calculating an absolute reference position through the controller to correct the absolute position deviation of the three Hall sensors; The specific formula of the absolute position deviation of the Hall sensor is as follows: Among them, θ eH is the absolute position deviation of the Hall sensor, in degrees, T is the time of each sector detected, T = (T I T II T III T IV T V T VI ) T , in milliseconds, T av is the average time of the detected sector, in milliseconds, E = (111111) T ; Step 4, the actual position of the rotor is expressed by the absolute position deviation of step 3; In step 4, three consecutive sectors are selected to reflect all the information of the absolute position deviation; Step 5, by selecting three consecutive sectors to reflect all the information of the absolute position deviation, and by establishing the minimum variance estimation of the absolute position deviation to express the complete absolute position deviation correction equation; In step 5, the first three sectors are selected to establish the existence estimation parameters The augmented equation of the absolute position deviation and relative deviation is as follows: in, is the estimated value of the absolute position deviation of Hall sensor A in degrees, is the relative deviation between Hall sensor B and Hall sensor A, in degrees, is the relative deviation between Hall sensor C and Hall sensor B, in degrees; Step 6, the timer of the controller measures the corresponding time and calculates the relative position deviation of the Hall sensor, thereby obtaining a position compensation scheme for the Hall sensor, thereby performing position compensation for the Hall sensor; In step 6, the relative position deviation of the Hall sensor is obtained by measuring the corresponding time through the timer of the controller, thereby expressing the absolute position deviation correction value of the Hall sensor. The specific formula is as follows: in, is the estimated value of the absolute position deviation of Hall sensor A in degrees, is the estimated value of the absolute position deviation of Hall sensor B in degrees, is the estimated value of the absolute position deviation of Hall sensor C in degrees, is the relative deviation between Hall sensor A and Hall sensor C, in degrees, is the relative deviation between Hall sensor B and Hall sensor A, in degrees, is the relative deviation between Hall sensor C and Hall sensor B, in degrees; The three Hall sensors all have absolute position deviations during the installation process, which will cause the motor to fail to start normally. The estimated correction term of the Hall sensor absolute position deviation is to compensate for and correct the absolute position deviation of the Hall sensor during the installation process in actual operation. Therefore, during the control process, the time of the first three sectors is used for real-time calculation to obtain the estimated correction term of the Hall sensor absolute position deviation, as shown in the following formula: Among them, θ com is the estimated correction term for the absolute position deviation of the Hall sensor, in degrees, T i and T i-2 T is the detected sector time in milliseconds. av The average time of the detected sectors in milliseconds.

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