Construction method of high-speed sensorless discrete compensation controller of electro-magnetic synchronous motor

Abstract

The invention discloses a construction method of a high-speed sensorless discrete compensation controller of an electrically excited synchronous motor. The construction method comprises the following steps: constructing a back electromotive force state filter of which the input is actual current, actual electricity and electrical angular velocity and the output is back electromotive force; constructing a phase-locked loop with back electromotive force as input and electrical angle and electrical angular velocity as output; calculating a composite current error and a voltage error, calculating a delayed voltage signal value based on the voltage error, subtracting the voltage error from the voltage signal value to obtain a voltage control value, and calculating a control voltage to form a composite vector current controller; according to the improved composite vector current controller, a modified value of a twiddle factor generated by voltage, current and back electromotive force signals due to phase errors is introduced to compensate an output voltage signal, the working condition under the high rotating speed can be better adapted, one-step delay of the controller is considered, meanwhile, two-beat delay is considered in the composite vector current controller, and the control precision is improved. And the two are combined to realize high-precision sensorless control.

Description

Technical Field

[0001] The invention belongs to the technical field of motor control, and relates to a controller of an electrically excited synchronous motor, in particular to a construction method of a controller of an electrically excited synchronous motor. Background Art

[0002] At present, permanent magnet motors are one of the most widely used motors in current electrical drive systems. They have the advantages of simple structure, light weight and high efficiency. However, the scarcity, price fluctuation and high pollution of rare earth materials have restricted their development. In addition, the increase in winding copper loss caused by the weak magnetic field speed increase affects the efficiency in the high-speed area. In contrast, the Electrical Excited Synchronous Motor (EESM) has low cost, controllable excitation, good short-circuit fault tolerance and electromechanical transient characteristics, and is suitable for the power generation field. It has become an ideal drive motor at high speed and is widely used in electric vehicles, all-electric aircraft and electrified rail transportation.

[0003] In practical applications, high-speed and even ultra-high-speed motors operate at high frequencies, which poses a challenge to the discrete-time control of digital controllers. Reference [1] "H. Zeng, J. Swanke, D. Bobba, B. Sarlioglu, TM Jahns. Discrete-Time Torque Control of High-Speed ​​SPM Machine For Aircraft Electric Propulsion [C]. 2020 IEEE Energy Conversion Congress and Exposition (ECCE), Detroit, MI, USA, 2020: 6325-6331." proposes a discrete-time torque control method for a high-speed surface-mounted permanent magnet synchronous motor (SPM) for an aviation electric propulsion system, and improves the dynamic performance of the motor by optimizing the control algorithm. Patent No. CN117895840A discloses a parameter design method for a complex vector current controller for bandwidth matching, which can achieve good control effects when there is a delay in the current loop. The patent with publication number CN113422550A discloses a low-carrier ratio control method for high-speed motors based on complex vector decoupling and delay compensation. Complex vector decoupling is introduced in the current regulator, and the current sampling delay and position delay are accurately compensated, so that the high-speed motor can operate stably under the low-carrier ratio state. However, the above methods are essentially not free from the limitations of the PI module, and are limited by parameter setting and applicable bandwidth range. In addition, the phase error caused by the delay of the digital controller during the implementation process is not taken into account. Therefore, it is urgent to design a controller that overcomes the limitations of PI parameters and fully considers and compensates for the delay effect. Summary of the invention

[0004] The object of the present invention is to solve the above problems and provide a method for constructing a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor taking into account delay factors, so as to achieve high-precision sensorless control of the electrically excited synchronous motor at high speed.

[0005] To achieve the above object, the technical solution adopted by the construction method of the high-speed sensorless discrete compensation controller of the electrically excited synchronous motor of the present invention comprises the following steps:

[0006] Step 1): Construct input as control voltage and electrical angle The output is the actual current i d ,i q and the actual voltage u d ,u q , a composite controlled object including an electrically excited synchronous motor;

[0007] Step 2): Construct the input as the actual current i d ,i q , actual voltage u d ,u q and electrical angular velocity Output is back EMF Back EMF state filter;

[0008] Step 3): Construct the input as the back electromotive force Output is electrical angle and electrical angular velocity Phase-locked loop;

[0009] Step 4): The speed conversion module uses electrical angular velocity is the input and output speed The reference speed N ref and the speed The speed error N is obtained by subtracting * , speed error N * The reference current is obtained through PI regulation

[0010] Step 5): Set the reference current Recombination to get the reference composite current Calculate the composite current error Voltage Error Based on the voltage error Δu dq Calculate the voltage signal value after delay The voltage error Δu dq The voltage signal value is Make the difference to get the voltage control value Then calculate the control voltage in, ω bw is the corresponding desired closed-loop bandwidth, R is the set value of the resistor, △u dq (k-1) is △u dq After each running step k, the previous data is updated. yes After each running step k, the previous data is updated. yes After every two operation steps k, the previous data is updated, so that the input is the reference current. Actual current i d ,i q and electrical angular velocity Output is control voltage Composite vector current controller;

[0011] Step 6): Connect the composite vector current controller, back electromotive force state filter, phase-locked loop and speed conversion module to form a high-speed sensorless discrete compensation controller.

[0012] Furthermore, step 2) specifically includes: converting the actual current i d ,i q The actual composite current i is obtained by compounding dq , actual voltage u d ,u q The actual composite voltage u is obtained by compounding dq , the actual composite voltage u dq After the delay link and the rotation link, the voltage is obtained Then calculate the voltage u″ dq , The voltage u″ dq With voltage u″ dq Calculate the current The voltage u″ dq The negative signal is delayed by k steps to compensate the output back electromotive force. j is a complex number, T is the matrix transpose, k is the running step size, T s is the sampling time, yes When k in is -1 value, yes When k in is 1 Value, correction value of the rotation factor of the phase error generated by the voltage signal T s is the system sampling time, and are the observed values ​​of the resistance and inductance of the motor.

[0013] Furthermore, step 3) is specifically: first calculate the error signal value Then calculate the electrical angular velocity and electrical angle K Gp , K Gi G PI Proportional and integral coefficients of the module.

[0014] The beneficial effects of the present invention after adopting the above technical solution are as follows:

[0015] 1. Compared with the limitations of the PI controller used in the traditional control method in terms of parameter setting and applicable bandwidth range, the present invention designs an improved composite vector current controller based on direct synthesis, introduces the correction value of the rotation factor generated by the phase error of the voltage, current and back electromotive force signals to compensate the output voltage signal, and the expected closed-loop bandwidth used by the correction value of the rotation factor has no range limit, which can better adapt to the working conditions under high speed.

[0016] 2. In order to solve the problem that traditional sensorless control schemes have insufficient accuracy at high speeds and are difficult to accurately estimate the rotor position, the present invention designs a sensorless control structure based on a back-electromotive force state filter and a phase-locked loop in a synchronous reference frame. While taking into account the one-step delay of the controller, the two-beat delay is considered in the composite vector current controller. The combination of the two realizes high-precision sensorless control.

[0017] 3. The transfer function in the control process takes into account the factors that the motor parameters (resistance, inductance, etc.) change during the control process, and updates the parameters of the motor system in real time to improve the observation accuracy, thereby ensuring the control accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a block diagram of a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor constructed by the method of the present invention;

[0019] Figure 2 yes Figure 1 The block diagram of the composite controlled object;

[0020] Figure 3 yes Figure 1 The block diagram of the electric back electromotive force state filter in the figure;

[0021] Figure 4 yes Figure 1 The block diagram of the electric back electromotive force state filter in the figure;

[0022] Figure 5 yes Figure 1 The block diagram of the composite vector current controller in FIG.

[0023] In the figure: 11. composite vector current controller; 12. back electromotive force state filter; 13. phase-locked loop; 14. speed conversion module; 41. 2r / 2s conversion module; 42. SVPWM module; 43. three-phase inverter; 44. electrically excited synchronous motor; 45. 3s / 2r conversion module. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0025] like Figure 1 As shown, the constructed electrically excited synchronous motor high-speed sensorless discrete compensation controller is composed of a composite vector current controller 11, a back electromotive force state filter 12, a phase-locked loop 13 and a speed conversion module 14, and is connected to a composite controlled object including an electrically excited synchronous motor 44 to control the electrically excited synchronous motor 44.

[0026] The input of the speed conversion module 14 is the electrical angular velocity Signal, the output signal is the speed The expressions of the input and output of the signal, speed conversion module 14 are:

[0027]

[0028] Among them, p n is the number of pole pairs of the electrically excited synchronous motor.

[0029] The reference speed N ref The speed output by the signal and speed conversion module 14 The speed error N is obtained by subtracting * , speed error N * The reference current is output after adjustment by the PI module The signal is expressed as:

[0030]

[0031] Among them, K p is the proportional gain coefficient, K i is the integral gain coefficient. The PI parameter K is different for different motor models. p and K i It is set according to the control object.

[0032] like Figure 2 As shown, a composite controlled object is constructed to achieve complete control of the motor and external drive. The composite controlled object is composed of a 2r / 2s conversion module 41, an SVPWM module 42, a three-phase inverter 43, a 3s / 2r conversion module 45 and an electrically excited synchronous motor 44. The 2r / 2s conversion module 41, the SVPWM module 42 and the three-phase inverter 43 are connected in series in sequence, and the output end of the three-phase inverter 43 is connected to the 3s / 2r conversion module 45 and the electrically excited synchronous motor 44 respectively. and electrical angle As an input signal, it is input to the 2r / 2s transformation module 41. The input signal is also the output of the entire high-speed sensorless discrete compensation controller. After the coordinate transformation of the 2r / 2s transformation module 41, the output is a voltage The relationship between its output and input is expressed as follows:

[0033]

[0034] The 2r / 2s conversion module 41 outputs the voltage and As an input signal, it is input into the SVPWM module 42. After space vector pulse width modulation in the SVPWM module 42, six switch signals s1, s2, s3, s4, s5, s6 are obtained. The six switch signals s1, s2, s3, s4, s5, s6 are input into the three-phase inverter 43 to generate a voltage signal S a , S b , S c , voltage signal S a , S b , S c The input signal is input into the electric excitation synchronous motor 44 to make the motor run. The electric excitation synchronous motor 44 obtains the actual three-phase current i through the current and voltage sensors. a ,i b ,i c , three-phase voltage u a ,u b ,u c and electrical angle signal, the actual three-phase current i a ,i b ,i c , three-phase voltage u a ,u b ,u c and electrical angle The signal is input as an input signal to the 3s / 2r conversion module 45 to obtain the dq axis current i d ,i q and voltage u d ,u q The relationship between the output and input of the 3s / 2r conversion module 45 is expressed as follows:

[0035]

[0036] This constitutes an input voltage and electrical angle The output is the current i of the dq axis d ,i q Signal and voltage u d ,u qThe composite controlled object outputs the current i d ,i q and voltage u d ,u q As the input signal of the back electromotive force state filter 12.

[0037] like Figure 3 As shown, a back electromotive force state filter 12 is constructed, and its input is the current i output by the composite controlled object. d ,i q , voltage u d ,u q and the electrical angular velocity fed back by the phase-locked loop 13 The actual current i d ,i q The actual composite current i is obtained by compounding dq , actual voltage u d ,u q After compounding, the actual composite voltage u is obtained dq The actual composite current i dq With the transfer function Output current i″ dq The current difference is obtained by subtracting, and the current difference is then transferred through the transfer function Get voltage u″ dq , whose expression is:

[0038]

[0039] Among them, i dq is i d ,i q The composite current, u dq is the voltage u d ,u q The composite voltage, is the expected value of the rotation factor corresponding to the phase error caused by the delay, j is a complex number, generally represented by j in electrical engineering, k is the running step size, T s is the sampling time, yes When k in is -1 value, The correction value of the rotation factor of the phase error generated by the voltage signal is T s is the system sampling time, and are the observed values ​​of resistance and inductance, which can be obtained by offline table lookup or resistance / inductance observer.

[0040] The composite voltage u dq After the delay link and the rotation link, the voltage u″ is obtaineddq , whose expression is:

[0041]

[0042] yes When k in is 1

[0043] The voltage u″ dq With voltage u″ dq After adding, it is used as the transfer function The input and output signal are current i″ dq , whose expression is:

[0044]

[0045] in, is the observed value of the resistance, which can be obtained by an offline table lookup method or a resistance / inductance observer.

[0046] The voltage u″ dq The negative signal is delayed by k steps to compensate the output back electromotive force. signal and decompose it to get the back electromotive force The expression is:

[0047]

[0048] The input is thus formed as a current i d ,i q , voltage u d ,u q , electrical angular velocity Output is back EMF The back EMF state filter 12. The back EMF As the input signal of the phase-locked loop 13.

[0049] like Figure 4 As shown, a phase-locked loop 13 is constructed, and the back electromotive force observed by the back electromotive force state filter 12 is Analyze and obtain the rotor position and speed information.

[0050] The back EMF signal will be observed Respectively with the observed electrical angle The error signal value △e is obtained by multiplying the sine and cosine signals and performing composite calculation. The expression of the error signal value △e is:

[0051]

[0052] The error signal value △e passes through G PI The module transfer function outputs the observed electrical angular velocity Then the observed electrical angular velocity Integrate to get the electrical angle

[0053]

[0054] Among them, K Gp , K Gi G PI The module's proportional and integral coefficients, K Gp K G It is set according to the different motor models of the control object.

[0055] The input is constructed as back electromotive force. Output is electrical angle and electrical angular velocity Phase-locked loop 13.

[0056] like Figure 5 As shown, a composite vector current controller 11 is constructed, and the input of the composite vector current controller 11 is a reference current Signal, actual current i of dq axis d ,i q Signal and electrical angular velocity signal, the output of the composite vector current controller 11 is the control voltage The reference current The reference composite current obtained after recombination Actual current i d ,i q After recombination, the actual recombination current i is obtained. dq , and the composite current error Δi is obtained by subtracting dq :

[0057]

[0058] The current error signal Δi dq Input to the transfer function Calculate the voltage error Δu dq , whose expression is:

[0059]

[0060] Among them, B b is the composite voltage u dq The expected value of the rotation factor corresponding to the phase error caused by the delay, ω bw is the corresponding desired closed-loop bandwidth, which is set according to the different motor models of the control object. s is the system sampling time, R is the set value of the resistor, and are the observed values ​​of resistance and inductance, which can be obtained by offline table lookup or resistance / inductance observer.

[0061] Based on the voltage error Δu dq Calculate the voltage signal value after delay The voltage error Δu dq The voltage signal value after delay Take the difference to get the voltage control value Voltage control value The expression is:

[0062]

[0063] Among them, △u dq (k-1) represents △u dq After each running step length k, the previous data is updated once. is the correction value of the rotation factor of the phase error generated by the current signal.

[0064] The voltage control value By including the delay link and the transfer function Z -1 , A b , Z -2 , B b , Z -1 Z -2 It is equivalent to a temporary register, outputting the last 1 and last 2 data. Voltage control value The closed-loop positive feedback is modulated to obtain the control voltage and decomposed into control voltage The control voltage Output to the composite controlled object, control voltage The expression is:

[0065]

[0066]

[0067] A b is the current i dq The expected value of the rotation factor corresponding to the phase error caused by the delay, represent The data is updated every time a running step length k is passed. represent The data before the data update is performed every two running steps k.

[0068] The input is thus constituted as a reference current The actual current i of the dq axisd ,i q and electrical angular velocity Output is control voltage Composite vector current controller 11.

[0069] Finally, the composite vector current controller 11, the back electromotive force state filter 12, the phase-locked loop 13 and the speed conversion module 14 are connected to form a high-speed sensorless discrete compensation controller for the electrically excited synchronous motor, which is connected to a composite controlled object including the electrically excited synchronous motor 44 to achieve high-precision control of the electrically excited synchronous motor at high speed.

[0070] When the high-speed sensorless discrete compensation controller is working, after the electric excitation synchronous motor 44 is running, the detected motor three-phase voltage u A ,u B ,u C and three-phase current i A ,i B ,i C After 3s / 2r conversion, the output voltage u d ,u q and current i d ,i q signal to the back EMF state filter 12, and at the same time the current i d ,i q The back electromotive force is input into the composite vector current controller 11, and the back electromotive force state filter 12 obtains the back electromotive force through calculation and transformation. and And input to the phase-locked loop 13, output electrical angular velocity To the speed conversion module 14, and output the electrical angle at the same time To the composite controlled object, the speed conversion module 14 converts the electrical angular velocity Convert to speed With the reference speed signal N ref After subtraction, we get the speed error N * Then input it into the PI module and modulate it to get the current Will After inputting into the composite vector current controller 11, the output voltage and To the composite controlled object, after a series of transformations, the voltage signal S of the motor is obtained. a , S b , S c To the motor to drive the motor to run.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for constructing a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor, characterized in that The following steps are involved: Step 1): Construct input as control voltage and electrical angle The output is the actual current i d ,i q and the actual voltage u d ,u q , a composite controlled object including an electrically excited synchronous motor; Step 2): Construct the input as the actual current i d ,i q , actual voltage u d ,u q and electrical angular velocity Output is back EMF Back EMF state filter (12); Step 3): Construct the input as the back electromotive force Output is electrical angle and electrical angular velocity Phase-locked loop (13); Step 4): The speed conversion module (14) converts the electrical angular velocity is the input and output speed The reference speed N ref and the speed The speed error N is obtained by subtracting * , speed error N * The reference current is obtained through PI regulation Step 5): Set the reference current Recombination to get the reference composite current Calculate the composite current error Voltage Error Based on the voltage error Δu dq Calculate the voltage signal value after delay The voltage error Δu dq The voltage signal value is Take the difference to get the voltage control value Then calculate the control voltage in, ω bw is the corresponding desired closed-loop bandwidth, R is the set value of the resistor, △u dq (k-1) is △u dq After each running step k, the previous data is updated. yes After each running step k, the previous data is updated. yes After every two operation steps k, the previous data is updated, so that the input is the reference current. Actual current i d ,i q and electrical angular velocity Output is control voltage A composite vector current controller (11); Step 6): The composite vector current controller (11), the back electromotive force state filter (12), the phase-locked loop (13) and the speed conversion module (14) are connected to form a high-speed sensorless discrete compensation controller.

2. The method for constructing a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor according to claim 1, characterized in that: Step 2) is as follows: d ,i q The actual composite current i is obtained by compounding dq , actual voltage u d ,u q The actual composite voltage u is obtained by compounding dq , the actual composite voltage u dq After the delay link and the rotation link, the voltage is obtained Then calculate the voltage u″ dq , From the voltage u′ dq With voltage u″ dq Calculate the current The voltage u″ dq The negative signal is delayed by k steps to compensate the output back electromotive force. j is a complex number, T is the matrix transpose, k is the running step size, T s is the sampling time, yes When k in is -1 value, yes When k in is 1 Value, correction value of the rotation factor of the phase error generated by the voltage signal T s is the system sampling time, and are the observed values ​​of the resistance and inductance of the motor.

3. The method for constructing a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor according to claim 1, characterized in that: Step 3) is as follows: first calculate the error signal value Then calculate the electrical angular velocity and electrical angle K Gp , K Gi G PI Proportional and integral coefficients of the module.

4. The method for constructing a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor according to claim 1, characterized in that: In step 4), the speed p n is the number of pole pairs of the electrically excited synchronous motor.

5. The method for constructing a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor according to claim 1, characterized in that: In step 4), the reference current K p is the proportional gain coefficient, K i is the integral gain coefficient.

6. The method for constructing a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor according to claim 1, characterized in that: Step 1) specifically comprises: a composite controlled object is formed by a 2r / 2s conversion module (41), a SVPWM module (42), a three-phase inverter (43), a 3s / 2r conversion module (45) and an electrically excited synchronous motor, and the voltage is and electrical angle The voltage is input to the 2r / 2s conversion module (41), and the voltage is output after the coordinate conversion of the 2r / 2s conversion module (41). The 2r / 2s conversion module (41) outputs a voltage The six switching signals are input into the SVPWM module (42), and after space vector pulse width modulation in the SVPWM module (42), six switching signals are obtained. The six switching signals are input into the three-phase inverter (43) to generate voltage signals, which are input into the electrically excited synchronous motor to make the motor run.

7. The method for constructing a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor according to claim 6, characterized in that: The relationship between the output and input of the 3s / 2r conversion module (45) is:

8. The method for constructing a high-speed sensorless discrete compensation controller for an electrically excited synchronous motor according to claim 6, characterized in that: The relationship between the output and input of the 2r / 2s conversion module (41) is:

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