Permanent magnet synchronous motor sensorless control method, system and hardware circuit

Abstract

The invention belongs to the technical field of motor control, and relates to a permanent magnet synchronous motor sensorless control method, system and hardware circuit, angular velocity estimation is designed based on a q-axis current model under a two-phase rotating coordinate system, angular velocity estimation compensation is designed based on a d-axis current model, and a rotating speed correction coefficient is introduced. And dynamic compensation of the estimated angular velocity value is realized. An accurate angular velocity estimated value and an accurate rotor angle estimated value are obtained by constructing a Romberg observer with an angular velocity estimated value and a rotor angle estimated value as outputs based on a dq rotating coordinate system. Taking an angular velocity error obtained by a motor angular velocity given value and a motor angular velocity estimated value as input of an outer ring PI controller, so as to ensure that the angular velocity estimated value tracks the motor angular velocity given value and output a q-axis current reference value; taking the difference value between the q-axis current reference value and the q-axis current sampling value and the difference value between the d-axis current reference value and the d-axis current sampling value as the input of an inner ring PI controller so as to ensure the bandwidth and the influence capability on the load, and outputting a d-axis voltage reference value and a q-axis voltage reference value; and converting the d-axis voltage reference value and the q-axis voltage reference value into voltage reference values under a two-phase static coordinate system based on the rotor angle estimation value so as to divide SVPWM drive circuit sectors, select voltage vectors, calculate action time, control on and off time of a permanent magnet synchronous motor switching device, and control on-off time of the permanent magnet synchronous motor switching device. And the alternating current speed regulation performance of the permanent magnet synchronous motor without the position sensor under the Romberg observer method is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor control, and relates to permanent magnet synchronous motor control technology, and specifically, to a permanent magnet synchronous motor position sensorless control method, system and hardware circuit. Background Art

[0002] Permanent magnet synchronous motor (PMSM for short) has the advantages of high efficiency, small size, high power density, fast dynamic response and low noise, and is widely used in electric vehicles, rail transit traction and household appliances. Traditional permanent magnet motor control generally installs mechanical sensors such as rotary encoders or photoelectric encoders on the motor shaft to obtain rotor position and speed information, and feeds back to the vector controller for closed-loop control. However, the use of mechanical sensors not only increases the device cost and occupies the installation space, but also reduces the reliability of the control system, and is not applicable in some complex environments. Therefore, the research on position sensorless control algorithms has become a key technology to improve the application performance of permanent magnet motors.

[0003] In the PMSM sensorless control strategy, the flux method observes the rotor position through the stator flux, but this method is too sensitive to the motor parameters and has low speed accuracy in the low speed area; the extended Kalman filter method can extract observation information from random noise signals, but this method has huge computational complexity and high requirements for processors and sampling circuits, and is not very practical in engineering; the synovial observer method is a nonlinear control method based on synovial variable structure. This method is insensitive to changes in motor parameters and has good robustness, but there are serious jitter problems in specific intervals, which affects the control performance; compared with the above methods, the Romberg observer has a simple structure and easy algorithm implementation, so it is widely used in actual engineering. However, its problems such as large speed observation error, low control accuracy, and slow dynamic response have always affected the stability of the control system. Summary of the invention

[0004] In view of the above-mentioned problems existing in the prior art, the present invention provides a permanent magnet synchronous motor position sensorless control method, system and hardware circuit, which can realize dynamic compensation of speed, improve the estimation accuracy of rotor angle and speed, and effectively ensure the AC speed regulation performance of the permanent magnet synchronous motor without position sensor under the Romberg observer.

[0005] In a first aspect of the present invention, a position sensorless control method for a permanent magnet synchronous motor is provided, the steps of which include:

[0006] Model construction steps: using the d-axis current detection value, q-axis current detection value, d-axis reference voltage value, and q-axis reference voltage value in the two-phase rotating coordinate system as input, and the angular velocity estimation value and rotor angle estimation value as output, to construct a Romberg observer based on speed compensation;

[0007] Current conversion step: converting the three-phase current sampling values ​​of the permanent magnet synchronous motor in the three-phase stationary coordinate system into the d-axis current sampling values ​​and the q-axis current sampling values ​​in the two-phase rotating coordinate system;

[0008] Voltage calculation step: calculating a d-axis voltage reference value and a q-axis voltage reference value in a two-phase rotating coordinate system according to a d-axis current sampling value, a d-axis current estimation value, a q-axis current sampling value, and a q-axis current estimation value;

[0009] Estimation step: inputting the d-axis current sampling value, the q-axis current sampling value, the d-axis voltage reference value, and the q-axis voltage reference value into the Romberg observer to obtain an angular velocity estimation value and a rotor angle estimation value;

[0010] Control steps: given value ω by motor angular velocity * and the estimated motor angular velocity ω est Get the angular velocity error Δω e , the angular velocity error Δω e As the input of the outer loop PI controller, it ensures that the speed tracks the motor angular velocity given value and outputs the q-axis current reference value I q * ; Set the q-axis current reference value I q * The difference between the q-axis current sampling value and the d-axis current reference value I q * The difference between the d-axis current sampling value and the d-axis current sampling value is used as the input of the inner-loop PI controller to ensure the bandwidth and the ability to influence the load and output the d-axis voltage reference value and the q-axis voltage reference value; based on the rotor angle estimation value, the d-axis voltage reference value and the q-axis voltage reference value are converted into voltage reference values ​​in a two-phase stationary coordinate system to divide the SVPWM drive circuit sector, select the voltage vector and calculate the action time, so as to control the on-time and off-time of the permanent magnet synchronous motor switching device.

[0011] In some embodiments, the model building step further comprises:

[0012] Current increment calculation steps: Convert the voltage equation of the permanent magnet synchronous motor in the two-phase rotating coordinate system into a spatial state model, and then obtain the current increment expressed as:

[0013]

[0014] In the formula, i d is the d-axis current sampling value at the current moment, i q is the q-axis current sampling value at the current moment, i d and i q The three-phase current values ​​detected by the current sensor at the current moment in the three-phase stationary coordinate system are calculated through Calark transformation and Park transformation; ωest_last u is the estimated value of the motor angular velocity at the previous moment; d_last is the d-axis voltage reference value at the previous moment, u q_last is the q-axis voltage reference value at the previous moment; R s is the motor stator resistance, L d is the motor d-axis inductance in the two-phase rotating coordinate system, L q is the motor q-axis inductance in the two-phase rotating coordinate system, ψ f is the rotor flux; the current increment is discretized according to the sampling period to obtain the current increment of the current cycle compared with the previous cycle, which is expressed as:

[0015]

[0016] In the formula, Δi d is the d-axis discretized current increment, Δi q is the q-axis discretized current increment, i d_last is the d-axis current sampling value at the previous moment, i q_last is the q-axis current sampling value at the previous moment, i d_last and i q_last The three-phase current values ​​detected by the current sensor at the last moment in the three-phase stationary coordinate system are calculated through Calark transformation and Park transformation;

[0017] Current estimation model construction steps: Based on the current sampling value of the previous cycle and the discretized current increment, the d-axis current estimation model of the current cycle and the q-axis current estimation model of the current cycle are constructed and expressed as follows:

[0018]

[0019]

[0020] In the formula, i qest is the estimated value of the q-axis current at the current moment, i dest is the estimated value of the d-axis current at the current moment;

[0021] The steps of constructing the angular velocity prior model are as follows: the q-axis current model of the permanent magnet synchronous motor is used as the reference model, the q-axis current estimation model is used as the adjustable model, and the Lumberg current observation model is constructed. In the Lumberg current observation model, the current deviation between the q-axis current sampling value and the q-axis current estimation value is used as the input of the proportional-integral controller, and the back-electromotive force estimation value U is obtained after the proportional-integral controller. emf , the estimated back EMF is equivalent to ω of the q-axis current model prior *ψ f , taking the estimated back EMF as input and the motor prior angular velocity as output, the angular velocity prior model is constructed as:

[0022]

[0023]

[0024] In the formula, ω prior is the prior value of the motor angular velocity, U emf is the estimated value of back EMF, k corr is the speed correction factor, k p is the proportional adjustment coefficient, k i is the integral adjustment coefficient, s is the Laplace transform; the steps of constructing the angular velocity compensation model are as follows: taking the d-axis current model of the permanent magnet synchronous motor as the reference model and the d-axis current estimation model as the adjustable model, the angular velocity compensation model is constructed as: ω corr =k corr *(i d -i dest )

[0025] In the formula, ω corr is the motor angular velocity compensation value;

[0026] The steps of constructing the Romberg observer are as follows: The angular velocity estimation model is constructed based on the angular velocity prior model and the angular velocity compensation model, which is expressed as:

[0027] ω est =ω prior +ω corr

[0028] In the formula, ω est is the estimated value of the motor angular velocity;

[0029] The rotor angle value obtained by integrating the angular velocity estimate is expressed as:

[0030] θ=∫ω est dt

[0031] The rotor angle value is discretized to obtain the rotor angle estimation model expressed as:

[0032] θ(nT s )=θ((n-1)T s )+ω est T s

[0033] Where n is the number of sampling cycles, nT s is the nth sampling period, (n-1)T s is the n-1th sampling period, T s is the sampling period, θ(nT s ) is the electrical angle of the current cycle, i.e. the nth sampling cycle, θ((n-1)T s ) is the electrical angle of the n-1th sampling period, i.e. the previous sampling period;

[0034] The angular velocity estimation model and the rotor angle estimation model are combined to form the Romberg observer, which is expressed as:

[0035] ω est =ω prior +ω corr

[0036] θ(nT s )=θ((n-1)T s )+ω est T s .

[0037] In some embodiments, in the current increment calculation step, the voltage in the two-phase rotating coordinate system is expressed as:

[0038]

[0039] in,

[0040] ψ d =L d i d +ψ f

[0041] ψ q =L q i q

[0042] In the formula, ψ d is the d-axis stator flux in the two-phase rotating coordinate system, ψ q is the q-axis stator flux in the two-phase rotating coordinate system;

[0043] The spatial state model is expressed as:

[0044]

[0045] In some embodiments, in the model building step, the rotation speed correction coefficient k corr The setting of is given by the following formula:

[0046]

[0047] In the formula, k b is the speed correction proportional gain, which is determined by the q-axis current sampling value i q OK; k c is the speed correction integral gain, which is determined by the d-axis current sampling value i d and the d-axis current estimate i dest OK, r is the rotor flux.

[0048] In some embodiments, the d-axis current sampling value i d and the d-axis current estimate i of the previous cycle dest Determine the speed correction integral gain k c The specific principle is: if the d-axis current estimation value i of the previous cycle dest Less than the d-axis current sampling value i d When , then 1+k c Greater than 1; if the d-axis current estimate i of the previous cycle dest Greater than the d-axis current sampling value i d When , then 1+k c Less than 1; by the q-axis current sampling value i q Determine the speed correction proportional gain k b The specific principle is: if the q-axis current sampling value i q If greater than 0, the speed correction proportional gain k b Greater than 0; if the q-axis current sampling value i q If it is less than 0, the speed correction proportional gain k b Less than 0.

[0049] In some embodiments, in the current conversion step, the specific method of converting the three-phase current sampling values ​​of the permanent magnet synchronous motor into d-axis current sampling values ​​and q-axis current sampling values ​​in a two-phase rotating coordinate system is: converting the three-phase current sampling values ​​of the permanent magnet synchronous motor into two-phase current sampling values ​​in a two-phase stationary coordinate system through Clarke transformation, and then converting them into d-axis current sampling values ​​and q-axis current sampling values ​​in a two-phase rotating coordinate system through Park transformation.

[0050] In some embodiments, in the control step, the dq axis decoupling strategy adopts Id=0 decoupling, and the d axis current reference value I is given in the medium and high speed area. d * = 0, in the low speed area, the d-axis current is magnetized, that is, I d * >0 to ensure the load-carrying capacity at low speed.

[0051] A second aspect of the present invention provides a permanent magnet synchronous motor position sensorless control system, which is used to implement the permanent magnet synchronous motor position sensorless control method described in the first aspect of the present invention, comprising:

[0052] The model building module takes the d-axis current detection value, q-axis current detection value, d-axis reference voltage, and q-axis reference voltage in the two-phase rotating coordinate system as inputs, and takes the angular velocity estimation value and the rotor angle estimation value as outputs to build a Romberg observer based on speed compensation;

[0053] A current conversion module converts the three-phase current sampling values ​​of the permanent magnet synchronous motor in the three-phase stationary coordinate system into the d-axis current sampling values ​​and the q-axis current sampling values ​​in the two-phase rotating coordinate system;

[0054] A voltage calculation module calculates a d-axis voltage reference value and a q-axis voltage reference value in a two-phase rotating coordinate system according to a d-axis current sampling value, a d-axis current estimation value, a q-axis current sampling value, and a q-axis current estimation value;

[0055] The estimation module inputs the d-axis current sampling value, the q-axis current sampling value, the d-axis voltage reference value, and the q-axis voltage reference value into the Romberg observer to obtain an angular velocity estimation value and a rotor angle estimation value;

[0056] Control module, given by the motor angular velocity value ω * and the estimated angular velocity ω est Get the angular velocity error Δω e , the angular velocity error Δω e As the input of the outer loop PI controller, it ensures that the speed tracks the motor angular velocity given value and outputs the q-axis current reference value I q * ; Set the q-axis current reference value I q * The difference between the q-axis current sampling value and the d-axis current reference value I q * The difference between the d-axis current sampling value and the d-axis current sampling value is used as the input of the inner-loop PI controller to ensure the bandwidth and the ability to influence the load and output the d-axis voltage reference value and the q-axis voltage reference value; based on the rotor angle estimation value, the d-axis voltage reference value and the q-axis voltage reference value are converted into voltage reference values ​​in a two-phase stationary coordinate system to divide the SVPWM drive circuit sector, select the voltage vector and calculate the action time, so as to control the on-time and off-time of the permanent magnet synchronous motor switching device.

[0057] In some embodiments, the model building module further comprises:

[0058] The current increment calculation module converts the voltage equation of the permanent magnet synchronous motor in the two-phase rotating coordinate system into a spatial state model, thereby obtaining the current increment;

[0059] A current estimation model building module is used to build a d-axis current estimation model and a q-axis current estimation model of the current cycle based on the current sampling value of the previous cycle and the discretized current increment;

[0060] The angular velocity prior model building module uses the permanent magnet synchronous motor q-axis current model as the reference model and the q-axis current estimation model as the adjustable model to build a Lumberg current observation model. In the Lumberg current observation model, the current deviation between the q-axis current sampling value and the q-axis current estimation value is used as the input of the proportional-integral controller, and the back-electromotive force estimation value U is obtained after the proportional-integral controller. emf , the estimated back EMF is equivalent to ω of the q-axis current model prior *ψ f , taking the estimated value of back EMF as input and the motor prior angular velocity as output, an angular velocity model is generated;

[0061] An angular velocity compensation model building module uses the permanent magnet synchronous motor d-axis current model as a reference model and the d-axis current estimation model as an adjustable model to build an angular velocity compensation model;

[0062] The Romberg observer constructs a module that constructs an angular velocity estimation model based on an angular velocity prior model and an angular velocity compensation model; integrates the angular velocity estimation value to obtain a rotor angle value, and discretizes the rotor angle value to obtain a rotor angle estimation model; and combines the angular velocity estimation model and the rotor angle estimation model to form a Romberg observer.

[0063] In a third aspect, the present invention provides a permanent magnet synchronous motor hardware circuit, comprising:

[0064] A three-phase uncontrolled rectifier circuit, whose input is connected to a three-phase power grid, is used to convert three-phase alternating current into pulsating direct current;

[0065] The intermediate DC circuit has an input connected to the output of the three-phase uncontrolled rectifier circuit to convert the pulsating DC power into a stable DC power;

[0066] A three-phase inverter circuit, the input of which is connected to the output of the intermediate DC circuit, converting the smooth DC power into AC power for use by the permanent magnet synchronous motor;

[0067] A bus voltage sampling circuit is used to obtain the DC bus voltage in real time;

[0068] Three-phase current sampling circuit, used to obtain three-phase output current in real time;

[0069] SVPWM drive circuit, used to generate drive signals for driving power devices in a three-phase inverter circuit;

[0070] The DSP processor is configured to: receive the bus voltage signal sent by the bus voltage sampling circuit and the motor phase current sent by the three-phase current sampling circuit, execute the permanent magnet synchronous motor position sensorless control method described in the first aspect of the present invention, and control the SVPWM drive circuit to generate a drive signal.

[0071] Compared with the prior art, the advantages and positive effects of the present invention are:

[0072] (1) The present invention provides a method and system for controlling a permanent magnet synchronous motor without a position sensor, using a q-axis current model to obtain a current estimation value, and integrating the current deviation to obtain a back electromotive force containing speed information, and then obtain a speed priori value. Different from the traditional Romberg observer, the method and system have a simple structure and strong engineering applicability.

[0073] (2) The permanent magnet synchronous motor position sensorless control method and system of the present invention designs angular velocity compensation based on the d-axis current model, introduces a speed correction coefficient, and realizes the calculation of the dynamic compensation amount of the angular velocity error, thereby obtaining a more accurate estimate of the angular velocity and rotor angle, effectively ensuring the AC speed regulation performance of the permanent magnet synchronous motor without a position sensor under the Romberg observer method.

[0074] (3) The present invention provides a position sensorless control method and system for a permanent magnet synchronous motor, and proposes a method for adjusting the speed correction coefficient. The calculation of the coefficient is strongly correlated with the motor parameters and the control parameters, and can achieve self-adjustment of the parameters. It can be adapted to different motors, thus ensuring the versatility of the control method and system and having good engineering applicability.

[0075] (4) In the hardware circuit of the permanent magnet synchronous motor of the present invention, the DSP processor is configured to execute a position sensorless control method for the permanent magnet synchronous motor. The control method designs angular velocity compensation based on a d-axis current model, weakens the influence of inaccurate motor parameters on speed calculation, realizes dynamic angular velocity compensation, improves the estimation accuracy of the rotor angle and angular velocity, and effectively ensures the AC speed regulation performance of the permanent magnet synchronous motor without a position sensor under the Romberg observer method. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 This is a flow chart of a position sensorless control method for a permanent magnet synchronous motor according to an embodiment of the present invention;

[0077] Figure 2 A control block diagram of a position sensorless control method for a permanent magnet synchronous motor according to an embodiment of the present invention;

[0078] Figure 3 This is a principle block diagram of the Romberg current observation model described in an embodiment of the present invention;

[0079] Figure 4 This is a control block diagram of the Romberg current observation model described in an embodiment of the present invention;

[0080] Figure 5 is a principle block diagram of the angular velocity compensation model described in an embodiment of the present invention;

[0081] Figure 6This is a flow chart of the Romberg observer based on speed compensation according to an embodiment of the present invention;

[0082] Figure 7 This is a structural block diagram of a position sensorless control system for a permanent magnet synchronous motor according to an embodiment of the present invention;

[0083] Figure 8 The circuit diagram is a hardware circuit diagram of the permanent magnet synchronous motor according to an embodiment of the present invention.

[0084] In the figure, 1. model building module, 101. current increment calculation module, 102. current estimation model building module, 103. angular velocity model building module, 104. angular velocity compensation model building module, 105. Romberg observer building module, 2. current conversion module, 201. Clarke transformation module, 202. Park transformation module, 3. voltage calculation module, 4. estimation module, 5. control module, 601. three-phase uncontrolled rectifier circuit, 602. intermediate DC circuit, 603. three-phase inverter circuit, 604. bus voltage sampling circuit, 605. three-phase current sampling circuit, 606. SVPWM drive circuit, 607. DSP processor, 608. filter circuit, 609. pre-charge circuit, 610. pre-charge control circuit. DETAILED DESCRIPTION

[0085] The present invention is described in detail below by way of exemplary embodiments. However, it should be understood that elements, structures, and features in one embodiment may also be beneficially combined in other embodiments without further description.

[0086] In the traditional Romberg observer, the dq axis current estimation and speed are both dependent on the motor model L d , L q , R s and ψ f The accuracy of the motor is high, but in actual engineering, the motor parameters obtained by the parameter identification strategy often have certain errors, and the motor parameters often change under harsh working conditions such as high temperature, which will cause the observation of the speed observer to fail. In addition, when the load torque is disturbed or the motor speed changes, the lag effect in the integral and filtering links of the observer will cause observation errors in speed and position. The present invention provides a permanent magnet synchronous motor position sensorless control method, system and hardware circuit, and constructs a Romberg observer based on speed compensation. The observer obtains basic speed information through the q-axis current model, and then obtains the speed compensation value through the d-axis current model, which solves the problem of speed compensation in the motor parameter L. d , L q , R s and ψ fThe problem of inaccurate identification and reduced speed observation accuracy of the Romberg observer at the time of load disturbance is solved, so that the observed speed fluctuation is smaller, the accuracy is higher, and the dynamic response performance is improved. The above-mentioned permanent magnet synchronous motor position sensorless control method, system and hardware circuit are described in detail below with reference to the accompanying drawings.

[0087] See also Figure 1 , Figure 2 According to a first aspect of the present invention, there is provided a position sensorless control method for a permanent magnet synchronous motor, the steps of which include:

[0088] S1. Model construction steps: Taking the d-axis current detection value, q-axis current detection value, d-axis reference voltage value, and q-axis reference voltage value in the two-phase rotating coordinate system as input, and the angular velocity estimation value and rotor angle estimation value as output, the Romberg observer based on speed compensation is constructed as follows:

[0089]

[0090] in,

[0091]

[0092] ω corr =k corr *(i d -i dest )

[0093]

[0094]

[0095]

[0096] In the formula, ω est is the estimated value of the motor angular velocity, ω prior is the prior value of the motor angular velocity, ω corr is the motor angular velocity compensation value, n is the number of sampling cycles, nT s is the nth sampling period, (n-1)T s is the n-1th sampling period, T s is the sampling period, θ(nT s ) is the electrical angle of the current cycle, i.e. the nth sampling cycle, θ((n-1)T s ) is the electrical angle of the n-1th sampling period, i.e. the previous sampling period; U emf is the estimated value of back EMF, ψ f is the rotor flux, k corr is the speed correction factor, k p is the proportional adjustment coefficient, k iis the integral adjustment coefficient, s is the Laplace transform; i q is the q-axis current sampling value at the current moment, i d is the d-axis current sampling value at the current moment, i d and i q The three-phase current values ​​detected by the current sensor at the current moment in the three-phase stationary coordinate system are calculated through Calark transformation and Park transformation; i qest is the estimated value of the q-axis current at the current moment, i dest is the estimated value of the d-axis current at the current moment; i q_last is the q-axis current sampling value at the previous moment, i d_last is the d-axis current sampling value at the previous moment, i d_last and i q_last The three-phase current values ​​detected by the current sensor at the last moment in the three-phase stationary coordinate system are calculated through Calark transformation and Park transformation; ω est_last u is the estimated value of the motor angular velocity at the previous moment; d_last is the d-axis voltage reference value at the previous moment, u q_last is the q-axis voltage reference value at the previous moment; R s is the motor stator resistance, L d is the motor d-axis inductance in the two-phase rotating coordinate system, L q is the q-axis inductance of the motor in the two-phase rotating coordinate system.

[0097] Specifically, see Figure 3 , the model building step further comprises:

[0098] S11. Convert the voltage equation of the permanent magnet synchronous motor in the two-phase rotating coordinate system into a spatial state model, and then obtain the current increment expressed as:

[0099]

[0100] The current increment is discretized according to the sampling period to obtain the current increment of the current cycle compared with the previous cycle, which is expressed as:

[0101]

[0102] In the formula, Δi d is the d-axis discretized current increment, Δi q is the q-axis discretized current increment.

[0103] Specifically, the voltage in the two-phase rotating coordinate system is expressed as:

[0104]

[0105] in,

[0106] ψd =L d i d +ψ f

[0107] ψ q =L q i q

[0108] In the formula, ψ d is the d-axis stator flux in the two-phase rotating coordinate system, ψ q is the q-axis stator flux in the two-phase rotating coordinate system;

[0109] The spatial state model is expressed as:

[0110]

[0111] S12, current estimation model construction step: based on the current estimation value of the previous cycle and the discretized current increment, the d-axis current estimation model and the q-axis current estimation model are constructed and expressed as:

[0112] S13, angular velocity model construction steps: see Figure 4 , taking the q-axis current model of the permanent magnet synchronous motor as the reference model and the q-axis current estimation model as the adjustable model, a Lumberg current observation model is constructed. In the Lumberg current observation model, the current deviation between the q-axis current sampling value and the q-axis current estimation value is used as the input of the proportional-integral controller, and the back-electromotive force estimation value U is obtained after the proportional-integral controller. emf , the estimated back EMF is equivalent to ω of the q-axis current model prior *ψ f , taking the estimated back EMF as input and the motor prior angular velocity as output, the angular velocity prior model is constructed as:

[0113]

[0114] See also Figure 5 , the open-loop transfer function of the Romberg current observation model is:

[0115]

[0116] Considering stability, offset the poles of the q-axis model, let:

[0117]

[0118] Then the open-loop transfer function is obtained:

[0119]

[0120] The closed-loop transfer function is further obtained:

[0121]

[0122] The simplified Romberg current observation model is a first-order inertia link, and the rise time is:

[0123] Where, t r is the rise time;

[0124] Let the rise time t r NT s , and then we get:

[0125]

[0126] In engineering, a reasonable value of N can be selected based on the response speed and overshoot.

[0127] S14, angular velocity compensation model construction steps: see Figure 6 , taking the permanent magnet synchronous motor d-axis current model as the reference model and the d-axis current estimation model as the adjustable model, the angular velocity compensation model is constructed as:

[0128] ω corr =k corr *(i d -i dest ) (8).

[0129] Specifically, from formula (3), we can know:

[0130]

[0131] The prior angular velocity ω is obtained through the q-axis current model prior , assuming that the angular velocity compensation value is ω corr , formula (9) can be written as:

[0132]

[0133] The corresponding d-axis correction is:

[0134]

[0135] The electrical angular velocity compensation value is expressed as:

[0136] ω corr =k corr *(i d -i dest )

[0137] Then the current correction value expressed by equation (11) can be written as:

[0138]

[0139] It should be noted that in the control process, the estimated d-axis current value i dest Infinitely close to the d-axis current sampling value i d , if i in the previous cycle dest d , then the desired current correction value Δi dcorr >0. If the q-axis current sampling value i q >0, then the correction factor k corr >0, if the q-axis current sampling value i q <0, then k corr <0; if i in the previous cycle dest >i d , then the above correction factor is the opposite.

[0140] Specifically, the speed correction coefficient k corr The setting of is given by the following formula:

[0141]

[0142] In the formula, k b is the speed correction proportional gain, which is determined by the q-axis current sampling value i q OK; k c is the speed correction integral gain, which is determined by the d-axis current sampling value i d and the d-axis current estimate i dest OK, r is the rotor flux.

[0143] Specifically, the d-axis current sampling value i d and the d-axis current estimate i of the previous cycle dest Determine the speed correction integral gain k c The specific principle is: if the d-axis current estimation value i of the previous cycle dest Less than the d-axis current sampling value i d When , then 1+k c Greater than 1; if the d-axis current estimate i of the previous cycle dest Greater than the d-axis current sampling value i d When , then 1+k c Less than 1; by the q-axis current sampling value i q Determine the speed correction proportional gain k b The specific principle is: if the q-axis current sampling value i q If greater than 0, the speed correction proportional gain k b Greater than 0; if the q-axis current sampling value i q If it is less than 0, the speed correction proportional gain k b Less than 0. ​

[0144] In some specific embodiments, when i q >0, k b =0.1, when i q <0, k b =-0.1; when i in the previous cycle dest d When k c =0.25; when i in the previous cycle dest >i d When k c = -0.25. S15, Romberg observer construction steps: According to the angular velocity prior model and the angular velocity compensation model, an angular velocity estimation model is constructed, which is expressed as:

[0145] ω est =ω prior +ω corr

[0146] The rotor angle value obtained by integrating the angular velocity estimate is expressed as:

[0147] θ=∫ω est dt

[0148] The rotor angle value is discretized to obtain the rotor angle estimation model expressed as:

[0149] θ(nT s )=θ((n-1)T s )+ω est T s

[0150] The angular velocity estimation model and the rotor angle estimation model are combined to form a Romberg observer.

[0151] S2. Current conversion step: converting the three-phase current sampling values ​​of the permanent magnet synchronous motor into d-axis current sampling values ​​and q-axis current sampling values ​​in a two-phase rotating coordinate system.

[0152] Specifically, the specific method of converting the three-phase current sampling values ​​of the permanent magnet synchronous motor into the d-axis current sampling values ​​and the q-axis current sampling values ​​in the two-phase rotating coordinate system is as follows: the three-phase current sampling values ​​of the permanent magnet synchronous motor (i a 、i b 、i c ) is converted into the two-phase current sampling value (i α 、i β ), and then converted into the d-axis current sampling value i in the two-phase rotating coordinate system through Park transformation d and q-axis current sampling value i q .

[0153] ​S3, voltage calculation step: calculate the d-axis voltage reference value and the q-axis voltage reference value in the two-phase rotating coordinate system according to the d-axis current sampling value, the d-axis current estimation value, the q-axis current sampling value, and the q-axis current estimation value.

[0154] S4, estimation step: input the d-axis current sampling value, the q-axis current sampling value, the d-axis voltage reference value, and the q-axis voltage reference value into the Romberg observer to obtain the angular velocity estimation value and the rotor angle estimation value.

[0155] S5, control step: given value ω by motor angular velocity * and the estimated motor angular velocity ω est Get the angular velocity error Δω e , the angular velocity error Δω e As the input of the outer loop PI controller, it ensures that the speed tracks the motor angular velocity given value and outputs the q-axis current reference value I q * ; Set the q-axis current reference value I q * The difference between the q-axis current sampling value and the d-axis current reference value I q * The difference between the d-axis current sampling value and the d-axis current sampling value is used as the input of the inner loop PI controller to ensure the bandwidth and the ability to influence the load and output the d-axis voltage reference value and the q-axis voltage reference value; based on the rotor angle estimation value, the d-axis voltage reference value and the q-axis voltage reference value are converted into the voltage reference value U in the two-phase stationary coordinate system α * , U β * , to divide the SVPWM drive circuit sectors, select the voltage vector and calculate the action time, and control the on and off time of the permanent magnet synchronous motor switch device. In some embodiments, in the control step, the dq axis decoupling strategy adopts Id=0 decoupling, and the d axis current reference value I is given in the medium and high speed area d * = 0, in the low speed area, the d-axis current is magnetized, that is, I d * >0 to ensure the load-carrying capacity at low speed.

[0156] The above-mentioned permanent magnet synchronous motor position sensorless control method of the embodiment of the present invention has a simple structure and strong engineering applicability in the constructed Lumberg observer. The q-axis current model is used to obtain the current estimation value, and the current deviation is integrated to obtain the back electromotive force containing the speed information, and then the angular velocity prior value is obtained. The angular velocity compensation is designed based on the d-axis current model, and the speed correction coefficient is introduced to realize the calculation of the dynamic compensation amount of the angular velocity error, so as to obtain a more accurate estimated angular velocity and rotor angle, which effectively guarantees the AC speed regulation performance of the permanent magnet synchronous motor without position sensor under the Lumberg observer method.

[0157] See also Figure 7 The second aspect of the present invention provides a permanent magnet synchronous motor position sensorless control system, which is used to implement the permanent magnet synchronous motor position sensorless control method described in the first aspect of the present invention, including:

[0158] Model construction module 1, takes the d-axis current detection value, q-axis current detection value, d-axis reference voltage, and q-axis reference voltage in a two-phase rotating coordinate system as input, and takes the angular velocity estimation value and the rotor angle estimation value as output, constructs a current conversion module 2 of a Romberg observer based on speed compensation, converts the three-phase current sampling value of the permanent magnet synchronous motor in a three-phase stationary coordinate system into the d-axis current sampling value and the q-axis current sampling value in a two-phase rotating coordinate system; voltage calculation module 3, calculates the d-axis voltage reference value and the q-axis voltage reference value in a two-phase rotating coordinate system according to the d-axis current sampling value, the d-axis current estimation value, the q-axis current sampling value, and the q-axis current estimation value;

[0159] The estimation module 4 inputs the d-axis current sampling value, the q-axis current sampling value, the d-axis voltage reference value, and the q-axis voltage reference value into the Romberg observer to obtain an angular velocity estimation value and a rotor angle estimation value;

[0160] Control module 5, given by the motor angular velocity value ω * and the estimated angular velocity ω est Get the angular velocity error Δω e , the angular velocity error Δω e As the input of the outer loop PI controller, it ensures that the speed tracks the motor angular velocity given value and outputs the q-axis current reference value I q * ; Set the q-axis current reference value I q * The difference between the q-axis current sampling value and the d-axis current reference value I q * The difference between the d-axis current sampling value and the d-axis current sampling value is used as the input of the inner-loop PI controller to ensure the bandwidth and the ability to influence the load and output the d-axis voltage reference value and the q-axis voltage reference value; based on the rotor angle estimation value, the d-axis voltage reference value and the q-axis voltage reference value are converted into voltage reference values ​​in a two-phase stationary coordinate system to divide the SVPWM drive circuit sector, select the voltage vector and calculate the action time, so as to control the on-time and off-time of the permanent magnet synchronous motor switching device.

[0161] In some embodiments, see Figure 7 , the model building module 1 further comprises:

[0162] The current increment calculation module 101 converts the voltage equation of the permanent magnet synchronous motor in the two-phase rotating coordinate system into a spatial state model, thereby obtaining the current increment;

[0163] The current estimation model building module 102 builds the d-axis current estimation model of the current cycle and the q-axis current estimation model of the current cycle based on the current sampling value of the previous cycle and the discretized current increment; the angular velocity model building module 103 uses the q-axis current model of the permanent magnet synchronous motor as a reference model and the q-axis current estimation model as an adjustable model to build a Lumberg current observation model. In the Lumberg current observation model, the current deviation between the q-axis current sampling value and the q-axis current estimation value is used as the input of the proportional-integral controller, and the back-electromotive force estimation value U is obtained after the proportional-integral controller. emf , the estimated back EMF is equivalent to ω of the q-axis current model prior *ψ f , taking the estimated value of back EMF as input and the motor prior angular velocity as output, an angular velocity model is generated;

[0164] An angular velocity compensation model building module 104 uses the permanent magnet synchronous motor d-axis current model as a reference model and the d-axis current estimation model as an adjustable model to build an angular velocity compensation model;

[0165] The Romberg observer constructs a module 105, which calculates an angular velocity estimation value according to an angular velocity prior model and an angular velocity compensation model; integrates the angular velocity estimation value to obtain a rotor angle value, discretizes the rotor angle value to obtain a rotor angle estimation value; and combines the angular velocity estimation model and the rotor angle estimation model to form a Romberg observer.

[0166] In some embodiments, see Figure 7 The current conversion module 2 further includes: a Clarke transformation module 201, which converts the three-phase current sampling value (i a 、i b 、i c After Clarke transformation, the two-phase current sampling values ​​(i α 、i β ); Park transformation module 202, the two-phase current sampling values ​​(i α 、i β ) is converted into the d-axis current sampling value i in the two-phase rotating coordinate system through Park transformation d and q-axis current sampling value i q .

[0167] The above-mentioned permanent magnet synchronous motor position sensorless control system of the embodiment of the present invention has a simple structure and strong engineering applicability in the constructed Lumberg observer. The q-axis current model is used to obtain the current estimation value, and the current deviation is integrated to obtain the back electromotive force containing the speed information, and then the speed prior value is obtained. The speed compensation is designed based on the d-axis current model, and the speed correction coefficient is introduced to realize the calculation of the dynamic compensation amount of the speed error, so as to obtain a more accurate estimated speed and rotor angle, which effectively guarantees the AC speed regulation performance of the permanent magnet synchronous motor without position sensor under the Lumberg observer method.

[0168] See also Figure 8 The third aspect of the present invention further provides a permanent magnet synchronous motor hardware circuit, including:

[0169] A three-phase uncontrolled rectifier circuit 601, whose input is connected to a three-phase power grid, is used to convert three-phase alternating current into pulsating direct current;

[0170] The intermediate DC circuit 602, whose input is connected to the output of the three-phase uncontrolled rectifier circuit, is used to convert the pulsating DC power into a stable DC power;

[0171] A three-phase inverter circuit 603, whose input is connected to the output of the intermediate DC circuit, converts the smooth DC power into AC power for use by the permanent magnet synchronous motor;

[0172] The bus voltage sampling circuit 604 is used to obtain the DC bus voltage in real time;

[0173] The three-phase current sampling circuit 605 is used to obtain the three-phase output current in real time;

[0174] SVPWM driving circuit 606, used to generate driving signals for driving power devices in the three-phase inverter circuit;

[0175] The DSP processor 607 is configured to: receive the bus voltage signal sent by the bus voltage sampling circuit and the motor phase current sent by the three-phase current sampling circuit, execute the permanent magnet synchronous motor position sensorless control method described in the embodiment of the first aspect of the present invention, and control the SVPWM drive circuit to generate a drive signal.

[0176] In some embodiments, see Figure 8 The intermediate DC circuit 602 is composed of a voltage-equalizing resistor R2 and a supporting capacitor C connected in parallel.

[0177] In some embodiments, the permanent magnet synchronous motor hardware circuit further includes a filter circuit 608, the front stage of which is connected to the three-phase power grid, and the rear end of which is connected to the three-phase uncontrolled rectifier circuit 601. Specifically, the filter circuit 68 is composed of an inductor L, and its function is to reduce the grid-side harmonic current and improve the power factor.

[0178] In some embodiments, the above-mentioned permanent magnet synchronous motor hardware circuit also includes a pre-charging circuit 609, which is connected between the three-phase power grid and the filter circuit 608. The pre-charging circuit 609 is connected to the DSP processor 607 through a pre-charging control circuit 610. The DSP processor 607 sends a pre-charging control signal to the pre-charging control circuit 610, and the pre-charging control circuit 609 controls the operation of the pre-charging circuit. The pre-charging circuit is set to reduce the charging current of the bus-side support capacitor C at the power-on time.

[0179] In some embodiments, the bus voltage sampling circuit, the three-phase current sampling circuit, and the SVPWM driving circuit adopt the bus voltage sampling circuit, the three-phase current sampling circuit, and the SVPWM driving circuit of existing conventional designs.

[0180] In some embodiments, the DSP processor uses an existing DSP chip on the market.

[0181] In the above-mentioned permanent magnet synchronous motor hardware circuit of the embodiment of the present invention, the DSP processor is configured to execute the permanent magnet synchronous motor position sensorless control method. The Lumberg observer constructed by the control method has a simple structure and strong engineering applicability. The q-axis current model is used to obtain the current estimation value, and the current deviation is integrated to obtain the back electromotive force containing the speed information, and then the speed prior value is obtained. The speed compensation is designed based on the d-axis current model to weaken the influence of the inaccurate motor parameters on the speed calculation, realize the dynamic compensation of the speed, improve the rotor angle and speed estimation accuracy, and effectively ensure the AC speed regulation performance of the permanent magnet synchronous motor without position sensor under the Lumberg observer method.

[0182] The above embodiments are used to explain the present invention rather than to limit the present invention. Any modification and change made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A position sensorless control method for a permanent magnet synchronous motor, characterized in that: The steps include: Model construction steps: take the d-axis current detection value, q-axis current detection value, d-axis reference voltage value, and q-axis reference voltage value in the two-phase rotating coordinate system as input, and take the angular velocity estimation value and the rotor angle estimation value as output, to construct a Romberg observer based on speed compensation; current conversion step: convert the three-phase current sampling value of the permanent magnet synchronous motor in the three-phase stationary coordinate system into the d-axis current sampling value and the q-axis current sampling value in the two-phase rotating coordinate system; voltage calculation step: calculate the d-axis voltage reference value and the q-axis voltage reference value in the two-phase rotating coordinate system according to the d-axis current sampling value, the d-axis current estimation value, the q-axis current sampling value, and the q-axis current estimation value; Estimation step: inputting the d-axis current sampling value, the q-axis current sampling value, the d-axis voltage reference value, and the q-axis voltage reference value into the Romberg observer to obtain an angular velocity estimation value and a rotor angle estimation value; Control steps: given value ω by motor angular velocity * The angular velocity error Δω is obtained by comparing the estimated angular velocity of the motor e , the angular velocity error Δω e As the input of the outer loop PI controller, it ensures that the speed tracks the motor angular velocity given value and outputs the q-axis current reference value I q * ; Set the q-axis current reference value I q * The difference between the q-axis current sampling value and the d-axis current reference value I q * The difference between the d-axis current sampling value and the d-axis current sampling value is used as the input of the inner-loop PI controller to ensure the bandwidth and the ability to influence the load and output the d-axis voltage reference value and the q-axis voltage reference value; based on the rotor angle estimation value, the d-axis voltage reference value and the q-axis voltage reference value are converted into voltage reference values ​​in a two-phase stationary coordinate system to divide the SVPWM drive circuit sector, select the voltage vector and calculate the action time, so as to control the on-time and off-time of the permanent magnet synchronous motor switching device.

2. The position sensorless control method for a permanent magnet synchronous motor according to claim 1, characterized in that: The model building step further comprises: Current increment calculation steps: Convert the voltage equation of the permanent magnet synchronous motor in the two-phase rotating coordinate system into a spatial state model, and then obtain the current increment expressed as: In the formula, i d is the d-axis current sampling value at the current moment, i q is the q-axis current sampling value at the current moment, i d and i q The three-phase current values ​​detected by the current sensor at the current moment in the three-phase stationary coordinate system are calculated through Calark transformation and Park transformation; ω est_last is the estimated value of the motor angular velocity at the previous moment; u d_last is the d-axis voltage reference value at the previous moment, u q_last is the q-axis voltage reference value at the previous moment; R s is the motor stator resistance, L d is the motor d-axis inductance in the two-phase rotating coordinate system, L q is the motor q-axis inductance in the two-phase rotating coordinate system, ψ f is the rotor flux; The current increment is discretized according to the sampling period to obtain the current increment of the current cycle compared with the previous cycle, which is expressed as: In the formula, Δi d is the d-axis discretized current increment, Δi q is the q-axis discretized current increment, i d_last is the d-axis current sampling value at the previous moment, i q_last is the q-axis current sampling value at the previous moment, i d_last and i q_last The three-phase current values ​​detected by the current sensor at the last moment in the three-phase stationary coordinate system are calculated through Calark transformation and Park transformation; Current estimation model construction steps: Based on the current sampling value of the previous cycle and the discretized current increment, the d-axis current estimation model of the current cycle and the q-axis current estimation model of the current cycle are constructed and expressed as follows: In the formula, i qest is the estimated value of the q-axis current at the current moment, i dest is the estimated value of the d-axis current at the current moment; The steps of constructing the angular velocity prior model are as follows: the q-axis current model of the permanent magnet synchronous motor is used as the reference model, the q-axis current estimation model is used as the adjustable model, and the Lumberg current observation model is constructed. In the Lumberg current observation model, the current deviation between the q-axis current sampling value and the q-axis current estimation value is used as the input of the proportional-integral controller, and the back-electromotive force estimation value U is obtained after the proportional-integral controller. emf , the estimated back EMF is equivalent to ω of the q-axis current model prior *ψ f , taking the estimated back EMF as input and the motor prior angular velocity as output, the angular velocity prior model is constructed as: In the formula, ω prior is the prior value of the motor angular velocity, U emf is the estimated value of back EMF, k corr is the speed correction factor, k p is the proportional adjustment coefficient, k i is the integral adjustment coefficient, s is the Laplace transform; The steps of constructing the angular velocity compensation model are as follows: Taking the d-axis current model of the permanent magnet synchronous motor as the reference model and the d-axis current estimation model as the adjustable model, the angular velocity compensation model is constructed as: ω corr =k corr *(i d -i dest ) In the formula, ω corr is the motor angular velocity compensation value; The steps of constructing the Romberg observer are as follows: The angular velocity estimation model is constructed based on the angular velocity prior model and the angular velocity compensation model, which is expressed as: oh est =ω prior +oh corr In the formula, ω est is the estimated value of the motor angular velocity; The rotor angle value obtained by integrating the angular velocity estimate is expressed as: θ=∫ω est dt The rotor angle value is discretized to obtain the rotor angle estimation model expressed as: θ(nT s )=θ((n-1)T s )+ω est T s Where n is the number of sampling cycles, nT s is the nth sampling period, (n-1)T s is the n-1th sampling period, T s is the sampling period, θ(nT s ) is the electrical angle of the current cycle, i.e. the nth sampling cycle, θ((n-1)T s ) is the electrical angle of the n-1th sampling period, i.e., the previous sampling period; the angular velocity estimation model and the rotor angle estimation model are combined to form a Romberg observer, which is expressed as: oh est =ω prior +oh corr θ(nT s )=θ((n-1)T s )+ω est T s 。 3. The position sensorless control method for a permanent magnet synchronous motor according to claim 2, characterized in that: In the current increment calculation step, the voltage in the two-phase rotating coordinate system is expressed as: in, ψ d =L d I d +ψ f ψ q =L q I q In the formula, ψ d is the d-axis stator flux in the two-phase rotating coordinate system, ψ q is the q-axis stator flux in the two-phase rotating coordinate system; The spatial state model is expressed as:

4. The position sensorless control method for a permanent magnet synchronous motor according to claim 2 or 3, characterized in that: In the model building step, the speed correction coefficient k corr The setting of is given by the following formula: In the formula, k b is the speed correction proportional gain, which is determined by the q-axis current sampling value i q OK; k c is the speed correction integral gain, which is determined by the d-axis current sampling value i d and the d-axis current estimate i dest OK, f is the rotor flux.

5. The position sensorless control method for a permanent magnet synchronous motor according to claim 4, characterized in that: The d-axis current sampling value i d and the d-axis current estimate i of the previous cycle dest Determine the speed correction integral gain k c The specific principle is: if the d-axis current estimation value i of the previous cycle dest Less than the d-axis current sampling value i d When , then 1+k c Greater than 1; if the d-axis current estimate i of the previous cycle dest Greater than the d-axis current sampling value i d When , then 1+k c Less than 1; by the q-axis current sampling value i q Determine the speed correction proportional gain k b The specific principle is: if the q-axis current sampling value i q If greater than 0, the speed correction proportional gain k b Greater than 0; if the q-axis current sampling value i q If it is less than 0, the speed correction proportional gain k b Less than 0.

6. The position sensorless control method for a permanent magnet synchronous motor according to claim 1, characterized in that: In the current conversion step, the specific method of converting the three-phase current sampling values ​​of the permanent magnet synchronous motor into the d-axis current sampling values ​​and the q-axis current sampling values ​​in the two-phase rotating coordinate system is: converting the three-phase current sampling values ​​of the permanent magnet synchronous motor into the two-phase current sampling values ​​in the two-phase stationary coordinate system through Clarke transformation, and then converting them into the d-axis current sampling values ​​and the q-axis current sampling values ​​in the two-phase rotating coordinate system through Park transformation.

7. The position sensorless control method for a permanent magnet synchronous motor according to claim 1, characterized in that: In the control step, the dq axis decoupling strategy adopts Id=0 decoupling, and the d axis current reference value I is given in the medium and high speed area. d * = 0, in the low speed area, the d-axis current is magnetized, that is, I d * >0 to ensure the load-carrying capacity at low speed.

8. A permanent magnet synchronous motor position sensorless control system, used to implement the permanent magnet synchronous motor position sensorless control method according to any one of claims 1 to 7, characterized in that: include: The model building module takes the d-axis current detection value, q-axis current detection value, d-axis reference voltage, and q-axis reference voltage in the two-phase rotating coordinate system as inputs, and takes the angular velocity estimation value and the rotor angle estimation value as outputs to build a Romberg observer based on speed compensation; A current conversion module converts the three-phase current sampling values ​​of the permanent magnet synchronous motor in the three-phase stationary coordinate system into the d-axis current sampling values ​​and the q-axis current sampling values ​​in the two-phase rotating coordinate system; a voltage calculation module calculates the d-axis voltage reference value and the q-axis voltage reference value in the two-phase rotating coordinate system according to the d-axis current sampling value, the d-axis current estimation value, the q-axis current sampling value, and the q-axis current estimation value; The estimation module inputs the d-axis current sampling value, the q-axis current sampling value, the d-axis voltage reference value, and the q-axis voltage reference value into the Romberg observer to obtain an angular velocity estimation value and a rotor angle estimation value; Control module, given by the motor angular velocity value ω * and the estimated angular velocity ω est Get the angular velocity error Δω e , the angular velocity error Δω e As the input of the outer loop PI controller, it ensures that the speed tracks the motor angular velocity given value and outputs the q-axis current reference value I q * ; Set the q-axis current reference value I q * The difference between the q-axis current sampling value and the d-axis current reference value I q * The difference between the d-axis current sampling value and the d-axis current sampling value is used as the input of the inner loop PI controller to ensure the bandwidth and the ability to influence the load and output the d-axis voltage reference value and the q-axis voltage reference value; Based on the estimated value of the rotor angle, the d-axis voltage reference value and the q-axis voltage reference value are converted into voltage reference values ​​in a two-phase stationary coordinate system to divide the SVPWM drive circuit sectors, select the voltage vector and calculate the action time to control the on and off time of the permanent magnet synchronous motor switching device.

9. The permanent magnet synchronous motor position sensorless control system according to claim 8, characterized in that: The model building module further comprises: The current increment calculation module converts the voltage equation of the permanent magnet synchronous motor in the two-phase rotating coordinate system into a spatial state model, thereby obtaining the current increment; A current estimation model building module is used to build a d-axis current estimation model of the current cycle and a q-axis current estimation model of the current cycle based on the current sampling value of the previous cycle and the discretized current increment; The angular velocity prior model building module uses the permanent magnet synchronous motor q-axis current model as the reference model and the q-axis current estimation model as the adjustable model to build a Lumberg current observation model. In the Lumberg current observation model, the current deviation between the q-axis current sampling value and the q-axis current estimation value is used as the input of the proportional-integral controller, and the back-electromotive force estimation value U is obtained after the proportional-integral controller. emf , the estimated back EMF is equivalent to ω of the q-axis current model prior *ψ f , taking the estimated value of back EMF as input and the motor prior angular velocity as output, an angular velocity model is generated; An angular velocity compensation model building module uses the permanent magnet synchronous motor d-axis current model as a reference model and the d-axis current estimation model as an adjustable model to build an angular velocity compensation model; The Romberg observer constructs a module that constructs an angular velocity estimation model based on an angular velocity prior model and an angular velocity compensation model; integrates the angular velocity estimation value to obtain a rotor angle value, and discretizes the rotor angle value to obtain a rotor angle estimation model; and combines the angular velocity estimation model and the rotor angle estimation model to form a Romberg observer.

10. A permanent magnet synchronous motor hardware circuit, characterized in that: include: A three-phase uncontrolled rectifier circuit, whose input is connected to a three-phase power grid, is used to convert three-phase alternating current into pulsating direct current; The intermediate DC circuit has an input connected to the output of the three-phase uncontrolled rectifier circuit to convert the pulsating DC power into a stable DC power; A three-phase inverter circuit, the input of which is connected to the output of the intermediate DC circuit, converting the smooth DC power into AC power for use by the permanent magnet synchronous motor; A bus voltage sampling circuit is used to obtain the DC bus voltage in real time; Three-phase current sampling circuit, used to obtain three-phase output current in real time; SVPWM drive circuit, used to generate drive signals for driving power devices in a three-phase inverter circuit; The DSP processor is configured to: receive the bus voltage signal sent by the bus voltage sampling circuit and the motor phase current sent by the three-phase current sampling circuit, execute the permanent magnet synchronous motor position sensorless control method described in any one of claims 1 to 7, and control the SVPWM drive circuit to generate a drive signal.

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