阅读说明：本技术 一种混合励磁磁通切换电机无位置传感器复合控制方法 (Position-sensorless compound control method for hybrid excitation flux switching motor ) 是由 张蔚 王家乐 杨泽贤 任鸿雷 翟良冠 于 2020-07-03 设计创作，主要内容包括：本发明公开了一种混合励磁磁通切换电机无位置传感器复合控制方法,在零低速域采用PHFVI估算电机转子速度和位置信息,用来解决启动以及低速运行问题,实现了该电机启动及稳定运行,且系统启动速度快、转子位置估计误差小；在中高速运行时,相较于传统的定子电流MRAS算法,改进型MRAS算法改善了转子位置误差大、转矩脉动大和重载性能不足的问题；为了实现改进型MRAS和PHFVI之间的平滑切换,采用加权平均值复合控制,去实现两种方法在转子位置观测上的平滑过渡,且过渡过程响应时间快,转子速度和位置抖动小。(The invention discloses a position-sensorless compound control method for a hybrid excitation flux switching motor, which adopts PHFVI to estimate the speed and position information of a motor rotor in a zero low-speed domain, is used for solving the problems of starting and low-speed operation, realizes the starting and stable operation of the motor, and has high system starting speed and small estimation error of the rotor position; during medium and high speed operation, compared with the traditional stator current MRAS algorithm, the improved MRAS algorithm improves the problems of large rotor position error, large torque pulsation and insufficient heavy load performance; in order to realize smooth switching between the improved MRAS and the PHFVI, the weighted average composite control is adopted to realize smooth transition of the two methods on the rotor position observation, and the transition process has short response time and small rotor speed and position jitter.)

1. A position sensorless compound control method of a hybrid excitation flux switching motor is characterized by comprising the following steps:

the rotating speed value output after calculation according to the composite controlThe control process is divided into: the first stage, when the rotating speed is

in the zero-low speed stage, a pulse vibration high-frequency voltage injection method is adopted to detect the rotating speed and the rotor position; detecting the rotating speed and the rotor position by adopting a weighted average algorithm in a transition stage; and in the middle-high speed stage, the rotating speed and the rotor position are estimated by adopting an improved model reference adaptive algorithm introduced with an excitation winding.

2. The hybrid excitation flux switching motor position sensorless compound control method according to claim 1,the values are respectively 10% and 15% of the rated rotating speed.

3. The position sensorless compound control method of the hybrid excitation flux switching motor according to claim 1, wherein the detecting the rotation speed and the rotor position in the zero low speed stage comprises the following specific steps:

step 1: superimposing a high-frequency voltage excitation on the d-axis and detecting the corresponding high-frequency response current generated in the motor

Step 2: after passing through a low-pass filter, obtaining an input signal of a zero low-speed stage rotor position estimation observerNamely:

the input signal may be applied if the rotor position estimation error value of the hybrid excitation flux switching machine is less than 30 °

wherein: l ═ L (L)_d+L_q)/2，ΔL＝(L_d-L_q)/2；V_injIs the amplitude, omega, of the injected high-frequency voltage_hIs the angular velocity, L, of the injected high-frequency voltage_dIs a direct axis inductor, L_qIs a quadrature axis inductor, and is characterized in that,

if adjustedIf the rotor position estimated value is zero, the rotor position estimated error value of the motor is also zero, namely the rotor position estimated value converges to the actual rotor position value; will be provided withAnd obtaining the estimated rotor angular velocity as the input of a proportional integrator of the position observer, and integrating the estimated rotor angular velocity to obtain the estimated rotor position.

4. The hybrid excitation flux switching motor position sensorless compound control method according to claim 1, wherein the detection of the rotation speed in the transition stageAnd rotor position

wherein the content of the first and second substances,the rotor position estimation angle for the zero low speed phase,estimating an angle for the rotor position at the medium to high speed stage;

5. The hybrid excitation flux switching motor position sensorless compound control method according to claim 1, wherein the estimated rotation speed in the middle-high speed stage

wherein: k_p、K_iProportional and integral coefficients, respectively, s denotes a complex variable, i_q、i_dAre respectively the alternating current and the direct current,

Technical Field

The invention relates to a motor control method, in particular to a control method of a hybrid excitation flux switching motor.

Background

The hybrid excitation magnetic flux switching motor has the advantages of high power density, excellent torque performance, easiness in maintenance and the like, and is widely applied to the fields of servo systems, industrial control, wind power generation and the like. At present, a vector control mode without a position sensor is adopted in many hybrid excitation flux switching motors, so that although the cost and the installation difficulty of the motors are reduced and the reliability of the system is improved, the control mode without the position sensor has certain limitation.

The common algorithms of a pulse vibration high-frequency voltage injection, a sliding mode observer, a back electromotive force integrator and the like without a position sensor are adopted, wherein the pulse vibration high-frequency voltage injection is suitable for the zero-speed and low-speed control operation of a motor, and in the low-speed operation, the position and the speed of a rotor are lagged due to the adoption of more filters, the dynamic response is slow, and the real-time tracking performance is poor. The sliding mode observer and the back electromotive force integrator are used for calculating the back electromotive force of the motor based on the motor model and detecting the rotating speed and the rotating self position angle of the motor, so that when the motor runs at a high speed, the two control methods are high in stability, quick in response and strong in robustness of a system.

Disclosure of Invention

The purpose of the invention is as follows: in view of the above prior art, a sensorless control is proposed that can achieve hybrid excitation flux switching motors over a wide speed range.

The technical scheme is as follows: a hybrid excitation flux switching motor position sensorless compound control method comprises the following steps:

the rotating speed value output after calculation according to the composite control

The control process is divided into: the first stage, when the rotating speed isTime, zero low speed stepThe length of the section is equal to the length of the section,

is the upper limit value of the rotating speed; second stage, when the rotating speed is

When the process is in the transition stage,

is the lower limit value of the rotating speed; third stage, when the rotating speed is

The medium-high speed stage is adopted;

in the zero-low speed stage, a pulse vibration high-frequency voltage injection method is adopted to detect the rotating speed and the rotor position; detecting the rotating speed and the rotor position by adopting a weighted average algorithm in a transition stage; and in the middle-high speed stage, the rotating speed and the rotor position are estimated by adopting an improved model reference adaptive algorithm introduced with an excitation winding.

Further, in the above-mentioned case,the values are respectively 10% and 15% of the rated rotating speed.

Further, the detecting the rotating speed and the rotor position in the zero low speed stage comprises the following specific steps:

step 1: superimposing a high-frequency voltage excitation on the d-axis and detecting the corresponding high-frequency response current generated in the motor

Step 2: after passing through a low-pass filter, obtaining an input signal of a zero low-speed stage rotor position estimation observerNamely:

the input signal may be applied if the rotor position estimation error value of the hybrid excitation flux switching machine is less than 30 °

Linearization, namely:

wherein: l ═ L (L)_d+L_q)/2，ΔL＝(L_d-L_q)/2；V_injIs the amplitude, omega, of the injected high-frequency voltage_hIs the angular velocity, L, of the injected high-frequency voltage_dIs a direct axis inductor, L_qIs a quadrature axis inductor, and is characterized in that,estimating an error angle for the rotor, t being time; LPF denotes a low pass filter; l is the average inductance, and Delta L is the half-differential inductance;

if adjusted

If the rotor position estimated value is zero, the rotor position estimated error value of the motor is also zero, namely the rotor position estimated value converges to the actual rotor position value; will be provided with

And obtaining the estimated rotor angular velocity as the input of a proportional integrator of the position observer, and integrating the estimated rotor angular velocity to obtain the estimated rotor position.

Further, the rotating speed is detected in the transition stageAnd rotor positionThe method comprises the following specific steps:

wherein the content of the first and second substances,

the rotor position estimation angle for the zero low speed phase,

estimating an angle for the rotor position at the medium to high speed stage;is the estimated rotational speed of the zero low-speed stage,is the estimated rotation speed of the medium-high speed stage; σ is a weighting factor.

Further, the rotation speed is estimated in the middle-high speed stageAnd rotor position

The method comprises the following specific steps:

wherein: k_p、K_iProportional and integral coefficients, respectively, s denotes a complex variable, i_q、i_dAre respectively the alternating current and the direct current,

the currents are estimated for the quadrature-direct axis respectively,ψ_mis a permanent magnet flux linkage, M_fMutual inductance amplitude, i, generated for the interaction of the field and armature windings_f、Respectively excitation current and estimated excitation current, L_q、L_dAre respectively a quadrature axis inductor and a direct axis inductor; the lambda is an intermediate constant value which is,L_fis the inductance of the field winding.

Has the advantages that: according to the hybrid excitation flux switching motor position-sensorless compound control method, the PHFVI is adopted to estimate the speed and position information of the motor rotor in the zero low-speed domain, so that the problems of starting and low-speed operation are solved, the starting and stable operation of the motor are realized, the starting speed of the system is high, and the estimation error of the rotor position is small; during medium and high speed operation, compared with the traditional stator current MRAS algorithm, the improved MRAS algorithm improves the problems of large rotor position error, large torque pulsation and insufficient heavy load performance; in order to realize smooth switching between the improved MRAS and the PHFVI, a weighted average control strategy is adopted to realize smooth transition of two methods on rotor position observation, and the transition process has short response time and small rotor speed and position jitter.

Drawings

Fig. 1 is a control block diagram of a hybrid excitation flux switching motor position sensorless compound control method according to an embodiment of the present invention;

FIG. 2 is a control block diagram of the PHFVI control system estimating rotor position according to an embodiment of the invention;

FIG. 3 is a schematic diagram of the variation of the weighting coefficients with rotational speed according to an embodiment of the present invention;

FIG. 4 is a graphical representation of the rotational speed and rotor position waveforms for PHFVI switching to modified MRAS as provided by an embodiment of the present invention; wherein a) is a oscillogram of actual and estimated rotation speeds, and b) is a oscillogram of actual and estimated rotor position angles;

FIG. 5 is a schematic representation of the improved MRAS switching to PHFVI speed and rotor position provided by an embodiment of the present invention; wherein a) is a waveform diagram of the actual rotating speed and the estimated rotating speed, and b) is a waveform diagram of the actual rotor position angle and the estimated rotor position angle.

Detailed Description

The invention is further explained below with reference to the drawings.

As shown in fig. 1, a position sensorless compound control method for a hybrid excitation flux switching motor includes the following steps:

the rotating speed value output after calculation according to the composite control

The control process is divided into: the first stage, when the rotating speed is

The zero low speed stage is adopted; second stage, when the rotating speed isThen, the transition stage is carried out; third stage, when the rotating speed is

The time is a medium-high speed stage.Is the upper limit value of the rotating speed,Is the lower limit value of the rotating speed;the values are respectively 10% and 15% of the rated rotating speed.

Wherein, zero low-speed stage adopts pulse vibration high frequency voltage injection method (PHFVI) to detect rotational speed and rotor position, specifically is:

step 1: superimposing a high-frequency voltage excitation on the d-axis and detecting the corresponding high-frequency response current generated in the motor

Step 2: after passing through a Low Pass Filter (LPF for short), an input signal of the PHFVI rotor position estimation observer is obtainedNamely:

the input signal may be applied if the rotor position estimation error value of the hybrid excitation flux switching machine is less than 30 °Linearization, namely:

wherein: l ═ L (L)_d+L_q)/2，ΔL＝(L_d-L_q)/2；V_injIs the amplitude, omega, of the injected high-frequency voltage_hIs the angular velocity, L, of the injected high-frequency voltage_dIs a direct axis inductor, L_qIs a quadrature axis inductor, and is characterized in that,

estimating an error angle for the rotor, t being time; LPF denotes a low pass filter; l is the average inductance, and Delta L is the half-differential inductance;

if adjustedIf the estimated rotor position error value is zero, the estimated rotor position error value is also zero, i.e. the estimated rotor position value converges to the actual rotor position value, the estimated rotor position value will be

Obtaining an estimated rotor angular velocity as an input to a position observer proportional integratorAnd integrating the estimated rotor angular velocity to obtain an estimated rotor position.

Detecting rotating speed by adopting weighted average algorithm in transition stage

And rotor position

The method specifically comprises the following steps:

wherein the content of the first and second substances,

the angle is estimated for the rotor position of the PHFVI,estimating an angle for a rotor position of an improved MRAS algorithm;

for the estimated rotational speed of the PHFVI,

an estimated rotational speed for an improved MRAS algorithm; σ is a weighting factor.

Estimating the rotating speed by adopting an improved Model Reference Adaptive (MRAS) algorithm introduced into an excitation winding at a medium-high speed stageAnd rotor position

The method specifically comprises the following steps:

step S41: and improving the determination of the MRAS adjustable model and the reference model.

The voltage equation of the hybrid excitation flux switching motor in the dq rotation coordinate axis is as follows:

in the formula u_d、u_qDq-axis voltages, respectively; i.e. i_d、i_qDq-axis currents, respectively; l is_d、L_qDq-axis inductances, respectively; psi_d、ψ_qRespectively, dq axis flux linkage, w_eIs the rotation speed; m_fA mutual inductance amplitude value generated for the interaction of the excitation winding and the armature winding; i.e. i_fIs the excitation winding current; u. of_fIs the excitation winding voltage; r_fIs an excitation winding resistor; psi_mIs a permanent magnet flux linkage; l is_fIs an excitation winding inductance; r_sIs the stator resistance.

For ease of analysis, equation (5) is written in the form of a current equation:

equation (6) transforms into:

order to

Equation (7) can be converted to equation (8).

Order to

Formula (8) may be arranged as formula (9).

Writing equation (9) as a state space model:

wherein:

the state matrix equation in equation (10) contains information on the rotational speed of the motor, and therefore, equation (10) is used as a reference model, ω_eIs an adjustable parameter to be identified.

Equation (9) is expressed as an estimated value as adjustable model equation (11).

In the formula (I), the compound is shown in the specification,estimating currents for dq axes, respectively;

to estimate the field winding current;

to estimate the rotational speed.

Defining a generalized error:

equation (9) minus equation (11) yields:

under the generalized error, the state space model of the control system can be simplified as follows:

wherein:

then, the error system established by equation (14) can be expressed as equation of state form (15).

In the formula (I), the compound is shown in the specification,

step S42: the determination of the MRAS reference adaptation law is improved.

According to the Popov inequality, one can obtain:

MRAS parameter estimation generally takes the form of simple proportional integral, as will be described hereinExpressed as:

is the initial value of the speed estimation.

Substituting equation (17) into equation (16) yields:

need to make

The formula (19) and the formula (20) are satisfied.

Constructing a function f (t) for the inequality (20) satisfies:

where k is greater than 0, substituting formula (21) into formula (18) may result in formula (22).

Taking the two equations (19) and (20) together, and then combining the first equation, equation (23) is obtained:

for equation (18), if the integrand is confirmed, the inequality holds, resulting in (24).

Bringing formula (24) into formula (20) yields:

accordingly, η₁(0,t₁) It was confirmed.

F is to be₁(y, t, τ) and F₂The substitution of (y, t) into the formula (17) can give the formula (26).

In formula (26):

the resulting rotational speed estimation formula is equation (28).

Wherein: k_p、K_iProportional and integral coefficients, respectively, s denotes a complex variable, i_q、i_dAre respectively the alternating current and the direct current,estimating the current, psi, for the quadrature-direct axes, respectively_mIs a permanent magnet flux linkage, M_fMutual inductance amplitude, i, generated for the interaction of the field and armature windings_f、Respectively excitation current and estimated excitation current, L_q、L_dAre respectively a quadrature axis inductor and a direct axis inductor; the lambda is an intermediate constant value which is,L_fis the inductance of the field winding.

Obtained according to formula (28)

I.e. rotor position in the medium-high speed stage

Formula (28) inner K_pAnd K_iAre numbers greater than zero and the position angle of the rotor can be obtained by velocity integration.

Obtained according to formula (29)

I.e. estimating the speed of rotation in the medium-high speed stage

According to the control block diagram shown in fig. 1, a hybrid excitation flux switching motor position sensorless composite control system simulation model is built under an MATLAB/Simulink environment, and motor parameters are selected as follows: the rated power is 600W, the rated rotation speed is 750rpm, the pole pair number is 14, the amplitude of the permanent magnet flux linkage is 0.0678Wb, the resistance of an armature winding is 2.32 omega, and the alternating-direct axis inductance and the direct-alternating axis inductance are 22.6mH and 23mH respectively. Under the conditions, setting a speed switching interval between PHFVI and an improved MRAS algorithm, performing multiple simulation tests, and designing a weighting interval to be 80r/min-120r/min by combining parameters of the hybrid excitation flux switching motor, namely

Then, simulation tests were performed on the speed switching back and forth between the two. As shown in fig. 4 and 5, I is represented as PHFVI alone control operation, ii is represented as modified MRAS algorithm alone control operation, and iii is represented as PHFVI and modified MRAS algorithm weighted switching control operation. It can be seen from fig. 4 and 5 that, no matter the PHFVI and the improved MRAS algorithms are independently controlled to operate, or the weighted average value switching control of the two algorithms is adopted, the estimated rotation speed of the rotor of the hybrid excitation flux switching motor can quickly track the actual rotation speed after mutation, and the result shows that the control strategy can realize the position-sensorless composite control operation of the hybrid excitation flux switching motor, and the rotation speed jitter is small and the response is fast.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.