A discrete hyperbolic tangent integral type motor position and speed estimation method and device

Abstract

The application discloses a kind of discrete hyperbolic tangent integral type motor position and speed estimation method and device, comprising the following steps;Three-phase current of motor is collected, voltage;Three-phase current, voltage is carried out Clark transformation, obtains the motor current signal and motor voltage signal under αβ coordinate system;The motor current signal and motor voltage signal under αβ coordinate system are respectively carried out Park transformation, obtain the motor current signal and motor voltage signal under the estimated dq coordinate system;Using the motor current signal under αβ coordinate system, motor current signal and motor voltage signal under the estimated dq coordinate system, calculate the motor error information of hyperbolic tangent type;The motor error information of hyperbolic tangent type is integrated and is discretized;Based on the position error after discrete integration, constructs the position and speed estimator of motor.The application inhibits system chattering, improves estimation accuracy, when the speed of motor changes greatly, with fast dynamic response and excellent steady-state accuracy.

Description

Technical Field

[0001] This invention belongs to the field of motor control technology, specifically relating to a method and apparatus for estimating the position and speed of a discrete semi-tangent integral motor. Background Technology

[0002] In positionless control of motors, it is necessary to estimate the motor's position and speed information. The most widely used technology in the field is the sliding mode observer, which uses the observed back electromotive force as input to construct a phase-locked loop (PLL) to estimate the motor's position and speed. However, since sliding mode control is inherently discontinuous, the control system exhibits constantly changing switching characteristics. This characteristic inevitably leads to system chattering due to factors such as non-ideal switching, limited system control force, spatial and temporal lags, and system inertia. Furthermore, when the motor speed varies significantly, existing PLL estimation algorithms suffer from slow response times and severe oscillation problems, and have poor disturbance suppression capabilities for motor speed estimation. Therefore, when the motor speed varies greatly, the PLL cannot quickly and accurately estimate the motor's position and speed, thus deteriorating the control performance of the positionless controller.

[0003] In summary, the existing technologies suffer from the following problems: Sliding mode observers employ sliding mode control, and chattering is an inherent characteristic of their control systems. Suppressing chattering weakens the system's robustness, so chattering cannot be completely suppressed; it can only be mitigated to a certain extent according to specific methods. Furthermore, when motor speed changes significantly, existing phase-locked loop (PLL)-based motor position and speed estimation algorithms suffer from slow dynamic response and oscillations, and the speed estimation has poor disturbance suppression capabilities. These problems severely impact the control performance of motors without position controllers. Summary of the Invention

[0004] To overcome the shortcomings of the existing technology, the present invention aims to provide a discrete semi-tangent integral motor position and speed estimation method and apparatus. On the one hand, it completely suppresses system chattering and improves estimation accuracy. On the other hand, it not only has excellent dynamic response speed but also good steady-state accuracy when the motor speed varies greatly.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A discrete semi-tangent integral method for estimating the position and velocity of a motor includes the following steps;

[0007] Step 1: Collect the three-phase current and three-phase voltage of the motor;

[0008] Step 2: Perform Clark transformation on the three-phase current and three-phase voltage to obtain the motor current signal and motor voltage signal in the αβ coordinate system;

[0009] Step 3: Perform Park transformation on the motor current signal and motor voltage signal in the αβ coordinate system respectively, where the estimated position is used in the Park transformation matrix, so as to obtain the estimated motor current signal and motor voltage signal in the dq coordinate system.

[0010] Step 4: Using the motor current signal in the αβ coordinate system, estimate the motor current signal and motor voltage signal in the dq coordinate system, and calculate the semi-tangent motor position error information.

[0011] Step 5: Integrate and discretize the semi-tangent motor position error information;

[0012] Step 6: Based on the position error after discrete integration, construct the position and speed estimator of the motor.

[0013] The three-phase current of the motor collected in step one is i a i b i c The three-phase voltage of the motor is collected as u a ,u b ,u c .

[0014] In step two, the collected three-phase motor currents are subjected to Clark transformation to obtain the motor current i in the αβ coordinate system. α i β The formula is:

[0015]

[0016] In step two, the collected three-phase motor voltages are subjected to Clark transformation to obtain the motor voltage u in the αβ coordinate system. α u β The formula is:

[0017]

[0018] In step three, the calculated motor current signal i in the αβ coordinate system is... α i β Perform the Park transformation, where the position used in the Park transformation matrix is... The estimated value of the motor position q is used to obtain the motor current signal in the predicted dq coordinate system. The specific formula is as follows:

[0019]

[0020] In step three, the calculated motor voltage signal u in the αβ coordinate system is... α u βPerform Park transformations separately, where the position used in the Park transformation matrix is... The estimated value of the motor position q is used to obtain the motor voltage signal in the predicted dq coordinate system. The specific formula is as follows:

[0021]

[0022] In step four, the specific formula for calculating the semi-tangent motor position error information is as follows:

[0023]

[0024] In the formula The difference between the actual position and the estimated position, w is the electric angular velocity of the motor, and y is the electric angular velocity of the motor. f It is a permanent magnet flux linkage.

[0025] In step five, the specific formula for integrating and discretizing the motor position error information is as follows:

[0026]

[0027] In the formula R is the difference between the actual position and the estimated position, L is the phase winding resistance of the motor, and L is the line inductance of the motor. a i b Let the current be in the αβ coordinate system. To estimate the current in the dq coordinate system, To estimate the voltage in the dq coordinate system, Let q be the estimated value of the motor position, T represent the control period, and l be the specific formula:

[0028]

[0029] In the formula Let q be the estimated value of the motor position, R be the phase winding resistance of the motor, L be the line inductance of the motor, and i be the value of the motor position. a i b Let the current be in the αβ coordinate system. To estimate the current in the dq coordinate system, To estimate the voltage in the dq coordinate system.

[0030] In step six, a position and speed estimator for the motor is constructed based on the position error after discrete integration. The specific formula is as follows:

[0031]

[0032]

[0033] in It is an estimated value of the electric angular velocity of the motor. It is an estimated value of the motor position q. k is the difference between the actual position and the estimated position. i ,k p These are design parameters.

[0034] A device for estimating motor position and speed parameters using a discrete semi-tangent integral motor position and speed estimation method based on direct calculation of a motor mathematical model includes a three-phase current sensor and a three-phase voltage acquisition circuit. The three-phase current sensor is used to acquire the three-phase current of the motor, and the three-phase voltage acquisition circuit is used to acquire the three-phase voltage of the motor. The acquired signals are filtered by a second-order filter, amplifier, analog-to-digital converter, and then estimated by a microcontroller unit to finally obtain the motor position and speed.

[0035] The beneficial effects of this invention are:

[0036] This invention completely suppresses system chattering and improves estimation accuracy. On the other hand, it has a fast dynamic response and excellent steady-state accuracy when the motor speed changes greatly.

[0037] This invention proposes a method for estimating motor position and speed, and proposes a corresponding hardware circuit. When the motor speed changes greatly, it has the advantages of suppressing system chattering, fast dynamic response speed and high steady-state accuracy. Attached Figure Description

[0038] Figure 1 This is a flowchart of the method for estimating the position and speed of a motor provided in an embodiment of the present invention.

[0039] Figure 2 This is a flowchart illustrating the method for estimating the position and speed of a motor provided in an embodiment of the present invention.

[0040] Figure 3 This is a schematic diagram of the structure of the motor position and speed estimation device provided in an embodiment of the present invention.

[0041] In the diagram: 1. Three-phase current sensor; 2. Three-phase voltage acquisition circuit; 3. Second-order filter; 4. Amplifier; 5. Analog-to-digital converter; 6. Microcontroller unit. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings.

[0043] like Figure 1 As shown, the method for estimating the position and speed of a motor provided in this embodiment of the invention includes the following steps:

[0044] S101: Collects three-phase current and three-phase voltage of the motor.

[0045] S102: Perform Clark transformation on the acquired three-phase current and three-phase voltage to obtain the motor current signal and motor voltage signal in the αβ coordinate system;

[0046] S103: Perform Park transformation on the calculated motor current signal and motor voltage signal in the αβ coordinate system to obtain the estimated motor current signal and motor voltage signal in the dq coordinate system.

[0047] S104: Calculate the motor position error information in the half-tangent type;

[0048] S105: Integrate and discretize the semi-tangent type motor position error information;

[0049] S106: Construct a position and speed estimator for the motor.

[0050] The application principle of the present invention will be further described below with reference to the accompanying drawings.

[0051] like Figure 2 As shown, the motor position and speed estimation method provided in this embodiment of the invention includes the following steps:

[0052] The first step is to collect the three-phase current of the motor as i. a i b i c The three-phase voltage of the motor is collected as u a ,u b ,u c ;

[0053] The second step is to perform the Clarke transform:

[0054]

[0055] Obtain the motor current i in the αβ coordinate system α i β ;

[0056]

[0057] Obtain the motor voltage u in the αβ coordinate system α u β ;

[0058] The third step is to perform the Park transformation:

[0059]

[0060] in It is the motor current signal estimated in the dq coordinate system.

[0061]

[0062] in It is the estimated motor voltage signal in the dq coordinate system.

[0063] The fourth step is to calculate the motor position error information in the half-tangent form:

[0064]

[0065] in The difference between the actual position and the estimated position, w is the electric angular velocity of the motor, and y is the electric angular velocity of the motor. f It is a permanent magnet flux linkage.

[0066] The fifth step is to integrate and discretize the semi-tangent motor position error information:

[0067]

[0068] in R is the difference between the actual position and the estimated position, L is the phase winding resistance of the motor, and L is the line inductance of the motor. a i b Let the current be in the αβ coordinate system. To estimate the current in the dq coordinate system, To estimate the voltage in the dq coordinate system, Let q be the estimated value of the motor position, T represent the control period, and l be the specific formula:

[0069]

[0070] Step 6: Construct the motor position and velocity estimation algorithm:

[0071]

[0072] in It is an estimated value of the motor position. It is an estimated value of the motor position q. k is the difference between the actual position and the estimated position. i ,k p These are design parameters.

[0073] like Figure 3 As shown, the electric position and velocity estimation device provided in this embodiment of the invention includes a three-phase current sensor 1, a three-phase voltage acquisition circuit 2, a second-order filter 3, an amplifier 4, an analog-to-digital converter 5, and a microcontroller unit 6.

[0074] The three-phase current sensor 1 collects the three-phase current of the motor, and the three-phase voltage acquisition circuit 2 collects the three-phase voltage of the motor. The collected signals are passed through a second-order filter 3, an amplifier 4, and an analog-to-digital converter 5. The microcontroller unit 6 then estimates the position and speed of the motor. The microcontroller unit 6 is a DSP or MCU that runs the motor position and speed estimation algorithm formula.

[0075] The estimated position and speed of the motor were compared with the actual position and speed of the motor obtained by the encoder. The results were basically consistent, proving that the estimation results of the present invention are accurate.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A discrete semi-tangent integral method for estimating the position and velocity of a motor, characterized in that, Includes the following steps; Step 1: Collect the three-phase current and three-phase voltage of the motor; Step two: Perform Clark transformation on the three-phase currents and three-phase voltages from step one to obtain... αβ Motor current signal and motor voltage signal in coordinate system; Step 3, the results obtained in Step 2 αβ The motor current signal and motor voltage signal in the coordinate system are respectively subjected to Park transform, where the estimated position is used in the Park transform matrix to obtain the predicted position. Motor current signal and motor voltage signal in coordinate system; Step four, using the results obtained in steps two and three αβ Motor current signal in coordinate system, prediction Calculate the motor position error information in half-tangent form using the motor current signal and motor voltage signal in the coordinate system; Step 5: Integrate and discretize the semi-tangent motor position error information; Step 6: Based on the position error after discrete integration, construct the position and speed estimators for the motor; In step five, the specific formula for integrating and discretizing the motor position error information is as follows: In the formula The difference between the actual position and the estimated position. This is the phase winding resistance of the motor. For motor line inductance, for αβ Current in coordinate system For the forecast Current in coordinate system For the forecast Voltage in coordinate system Motor position The estimated value, Indicates the control cycle. The specific formula is: In the formula Motor position The estimated value, This is the phase winding resistance of the motor. For motor line inductance, for αβ Current in coordinate system For the forecast Current in coordinate system For the forecast Voltage in a coordinate system.

2. The discrete semi-tangent integral motor position and velocity estimation method according to claim 1, characterized in that, The three-phase current of the motor collected in step one is... The three-phase voltage of the motor was collected. ; In step two, the collected three-phase motor currents are subjected to Clark transformation to obtain... αβ Motor current in coordinate system , The formula is: ； In step two, the collected three-phase motor voltages are subjected to Clark transformation to obtain... αβ Motor voltage in coordinate system , The formula is: 。 3. The discrete semi-tangent integral motor position and velocity estimation method according to claim 2, characterized in that, In step three, the calculated αβ Motor current signal in coordinate system , Perform the Park transformation, where the position used in the Park transformation matrix is... , Motor position The estimated value is obtained. Motor current signal in coordinate system , The specific formula is as follows: 。 4. The discrete semi-tangent integral motor position and velocity estimation method according to claim 3, characterized in that, In step three, the calculated αβ Motor voltage signal in coordinate system , Perform Park transformations separately, where the position used in the Park transformation matrix is... , Motor position The estimated value is obtained. Motor voltage signal in coordinate system , The specific formula is as follows: 。 5. The discrete semi-tangent integral motor position and velocity estimation method according to claim 1, characterized in that, In step four, the specific formula for calculating the semi-tangent motor position error information is as follows: In the formula The difference between the actual position and the estimated position. The electric angular velocity of the motor. It is a permanent magnet flux linkage.

6. The discrete semi-tangent integral motor position and velocity estimation method according to claim 1, characterized in that, In step six, a position and speed estimator for the motor is constructed based on the position error after discrete integration. The specific formula is as follows: in It is an estimated value of the motor position. Motor position The estimated value, The difference between the actual position and the estimated position. These are design parameters.

7. A device for estimating motor position and speed parameters using the discrete semi-tangent integral motor position and speed estimation method according to any one of claims 1-6, characterized in that, It includes a three-phase current sensor (1) and a three-phase voltage acquisition circuit (2). The three-phase current sensor (1) is used to acquire the three-phase current of the motor, and the three-phase voltage acquisition circuit (2) is used to acquire the three-phase voltage of the motor. The acquired signal is passed through a second-order filter (3), an amplifier (4), an analog-to-digital converter (5), and then the microcontroller unit (6) performs arithmetic calculations to estimate the motor position and speed.

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