阅读说明：本技术 一种永磁同步电机初始相位检测方法 (Method for detecting initial phase of permanent magnet synchronous motor ) 是由 刘雄 占颂 陈天航 苏小宇 唐小琦 王昌杰 陈威 唐沛然 周向东 江平 于 2019-10-22 设计创作，主要内容包括：本发明涉及一种永磁同步电机初始相位检测方法,属于永磁同步电机技术领域。现有技术中,存在检测转子初始相位偏差大甚至不能检测等问题。本发明提供了一种永磁同步电机伺服初始相位检测方法,该初始相位检测方法包括：速度环及电流环调节器模块、坐标变换模块、空间矢量脉冲宽度调制(SVPWM)模块、三相逆变电路模块、传感器及速度计算模块、永磁同步电机模块；具有初始相位检测误差小的特点。(The invention relates to a method for detecting an initial phase of a permanent magnet synchronous motor, and belongs to the technical field of permanent magnet synchronous motors. In the prior art, the problems that the initial phase deviation of a rotor is large or even the rotor cannot be detected exist. The invention provides a method for detecting a servo initial phase of a permanent magnet synchronous motor, which comprises the following steps: the device comprises a speed loop and current loop regulator module, a coordinate transformation module, a Space Vector Pulse Width Modulation (SVPWM) module, a three-phase inverter circuit module, a sensor and speed calculation module and a permanent magnet synchronous motor module; the method has the characteristic of small initial phase detection error.)

1. A method for detecting an initial phase by using a permanent magnet synchronous motor initial phase detection system is characterized by comprising the following steps: the system comprises a control unit;

the control unit initializes the initial phase detection system, and when t is 0, the control unit sets n to 0, α 0 to 0, and i to_dref＝I,i_qref＝0；

The control unit applies a d-axis voltage vector, the initial phase angle is alpha, and then whether the speed feedback value is 0 or not is judged; if the speed feedback value is not zero, let n be n +1, and correct phase angle α be α + α n, wherein

where t is the stabilization time, n is a natural number, i_drefIs d-axis command voltage, i_qrefThe motor is a q-axis command voltage, I is a d-axis applied current vector, the magnitude of the applied current vector can be set according to the rated current of the motor, and the range of the applied current vector is 80% -100% of the rated current.

2. The method of claim 1, wherein: the system also includes an incremental encoder disposed between the sensor and speed calculation module and the PMSM module.

3. A method for detecting an initial phase by using a permanent magnet synchronous motor initial phase detection system is characterized by comprising the following steps: the system comprises the sensor and speed calculation module, a control unit, an incremental photoelectric sensor and an encoder value change calculation module;

the control unit initializes the system to theta₀＝0，n＝0,θ＝θ₀,θ₁0; then, applying a voltage vector with an electrical angle theta and acquiring an encoder value variable d;

when d is not 0 and n is 0, judging whether d is greater than 0, if so, making theta₀180 degrees, theta₂360 degrees, d2 d 0-1, θ₁270 degrees, n is n + 1; if less than 0, let θ₀180 degrees, d0 d 2-1, θ₁90 degrees, n + 1; finally, let theta be equal to theta₁Applying the voltage vector with the electrical angle theta again, acquiring the encoder value variable d, and judging again;

when the value of d is not 0 and n is not 0, d1 is made to be d, whether d0 d1 is less than 0 is judged, and if the d is less than 0, theta is judged₂＝θ₁D2 ═ d 1; if greater than or equal to 0, θ₀＝θ₁D0 ═ d 1; finally make theta₁＝(θ₂+θ₀)/2,θ＝θ₁Applying the voltage vector with the electrical angle theta again, acquiring the encoder value variable d, and judging again;

outputting the initial phase theta of the rotor until d is 0 and keeps 1 s;

wherein theta is₀Represents the left boundary of the dichotomy phase, θ₂The right boundary, θ, representing the dichotomous phase₁The median value of the binary phase interval, i.e., the electrical angle of the next applied voltage vector, is represented by d0, d1, and d2, respectively, as the encoder value change amount corresponding to the left boundary voltage vector, the median voltage vector, and the right boundary voltage vector, respectively, of the search interval.

4. A method according to any one of claims 1-3, characterized in that: the system further comprises: the device comprises a speed loop and current loop regulator module, a coordinate transformation module, a Space Vector Pulse Width Modulation (SVPWM) module, a three-phase inverter circuit module, a sensor and speed calculation module and a permanent magnet synchronous motor module;

the command speed ω ref in combination with the speed feedback value output command is passed through an automatic speed regulator ASR (automatic speed regulator) of the speed loop and current loop regulator modulelatch) outputs q-axis command current i_qrefD-axis command current i_drefAnd q-axis command current i_qrefRespectively combining the d-axis current response signal and the q-axis current response signal, and respectively outputting a q-axis voltage u through an automatic current regulator ACR (automatic current regulator) of the speed loop and current loop regulator module_qD-axis voltage u_dQ-axis voltage u_qD-axis voltage u_dObtaining voltage signals under an alpha-beta coordinate system through ipark transformation of the coordinate transformation module, obtaining six switching signals through the Space Vector Pulse Width Modulation (SVPWM) module by the voltage signals under the alpha-beta coordinate system, obtaining three-phase voltages ua, ub and uc by the six switching signals through the three-phase inverter circuit module, obtaining current signals under a two-phase static alpha-beta coordinate system through Clark (Clark) transformation of the coordinate transformation module by the output currents ia and ib corresponding to ua and ub, obtaining d-axis current response signals and q-axis current response signals under a rotor synchronous rotation d-q coordinate system through park transformation of the coordinate transformation module by the current signals under the two-phase static alpha-beta coordinate system, obtaining d-axis current response signals and q-axis current response signals under a rotor synchronous rotation d-q coordinate system through ipark transformation of the coordinate transformation module, obtaining d-axis current response signals, The q-axis current response signal is a current loop feedback signal;

and three-phase voltages ua, ub and uc generated by the three-phase inverter circuit module are used as input voltages of the permanent magnet synchronous motor module, the sensor and the speed calculation module are used for detecting the rotating speed and the rotor position of the permanent magnet synchronous motor module, and the speed feedback value is output.

Technical Field

The invention relates to the technical field of permanent magnet synchronous motors, in particular to a method for detecting an initial phase by using an initial phase detection system of a permanent magnet synchronous motor.

Background

At present, many companies in the industries of food processing, chip manufacturing, automobile production, etc. introduce automatic production lines or increase the automation degree of the production lines. In order to ensure reliable production, high machining precision and the like, an automatic production line usually uses a servo control system. Compared with an electro-hydraulic servo control system, the permanent magnet synchronous motor servo control system can meet different power requirements, is simple and convenient to install, can realize high-precision control, and ensures the reliability of products.

The permanent magnet synchronous motor servo control system usually uses magnetic field directional control or direct torque control strategies, the control strategies require that the acquisition of the initial phase of a rotor and the correct connection of the phase sequence of a motor power line are completed in the starting stage, and the electric angle and the speed of the rotor can be acquired in real time after the motor is started.

The initial phase of the permanent magnet synchronous motor refers to the corresponding rotor initial position electrical angle before the motor is started, and the starting performance of a servo system is influenced by the accuracy of initial phase detection. By adopting the servo system of the magnetic field orientation control strategy, if the detection error of the initial phase of the rotor is large, the problem of abnormal starting of motor vibration or reversal and the like can be caused if the torque current output by the initial phase detection system is not on the q axis of the actual rotor, and the problem of high temperature of the permanent magnet can be caused if the output torque current has a component on the d axis of the actual rotor, so that the magnetic flux of the permanent magnet can be reduced in the service life cycle of the motor and the like can be caused. At present, speed sensors such as a magnetic grid sine and cosine encoder, an incremental photoelectric encoder and a Hall effect position sensor are used in the industry, the problems that the deviation of the initial phase of a rotor is large and even the rotor cannot be detected exist, high-precision equipment such as an absolute encoder and a rotary transformer is needed, and the cost of a servo system is increased. Therefore, the method has very important significance in researching the initial phase detection technology of the permanent magnet synchronous motor.

Disclosure of Invention

In view of the problems in the prior art, the invention provides a method for detecting an initial phase by using an initial phase detection system of a permanent magnet synchronous motor, which is characterized by comprising the following steps: the system comprises a control unit;

the control unit initializes the initial phase detection system, and when t is 0, the control unit sets n to 0, α 0 to 0, and i to_dref＝I,i_qref＝0；

The control unit applies a d-axis voltage vector, the initial phase angle is alpha, and then whether the speed feedback value is 0 or not is judged; if the speed feedback value is not zero, let n be n +1, and correct phase angle α be α + α n, wherein

Then the control unit applies the d-axis voltage vector again, the phase angle is alpha + alpha n, the speed feedback value is judged again until the speed feedback value is 0, and the stabilization time t is more than 0.5 s; finally, the control unit outputs the corrected phase angle alpha;

where t is the stabilization time, n is a natural number, i_drefIs d-axis command voltage, i_qrefThe motor is a q-axis command voltage, I is a d-axis applied current vector, the magnitude of the applied current vector can be set according to the rated current of the motor, and the range of the applied current vector is 80% -100% of the rated current.

Preferably, the system further comprises an incremental encoder disposed between the sensor and speed calculation module and the permanent magnet synchronous motor module.

The invention also provides a method for detecting the initial phase by using the permanent magnet synchronous motor initial phase detection system, which is characterized by comprising the following steps: the system comprises the sensor and speed calculation module, a control unit, an incremental photoelectric sensor and an encoder value change calculation module;

the control unit initializes the system to theta₀＝0，n＝0,θ＝θ₀,θ ₁0; then, applying a voltage vector with an electrical angle theta and acquiring an encoder value variable d;

when d is not 0 and n is 0, judging whether d is greater than 0, if so, making theta₀180 degrees, theta₂360 degrees, d2 d 0-1, θ₁270 degrees, n is n + 1; if less than 0, let θ₀180 degrees, d0 d 2-1, θ₁90 degrees, n + 1; finally, let theta be equal to theta₁Applying the voltage vector with the electrical angle theta again, acquiring the encoder value variable d, and judging again;

when the value of d is not 0 and n is not 0, d1 is made to be d, whether d0 d1 is less than 0 is judged, and if the d is less than 0, theta is judged₂＝θ₁D2 ═ d 1; if greater than or equal to 0, θ₀＝θ₁D0 ═ d 1; finally make theta₁＝(θ₂+θ₀)/2,θ＝θ₁Applying the voltage vector with the electrical angle theta again, acquiring the encoder value variable d, and judging again;

outputting the initial phase theta of the rotor until d is 0 and keeps 1 s;

wherein theta is₀Represents the left boundary of the dichotomy phase, θ₂The right boundary, θ, representing the dichotomous phase₁The intermediate value of the binary phase interval, i.e., the electrical angle of the next applied voltage vector, is represented by d0, d1, and d2, respectively, as the encoder value change amount corresponding to the left boundary voltage vector, the intermediate voltage vector, and the right boundary voltage vector in the search interval.

Preferably, the system further comprises: the device comprises a speed loop and current loop regulator module, a coordinate transformation module, a Space Vector Pulse Width Modulation (SVPWM) module, a three-phase inverter circuit module, a sensor and speed calculation module and a permanent magnet synchronous motor module;

the command speed omega ref is combined with a speed feedback value to output a command to output a q-axis command current i through an automatic speed regulator ASR (automatic speed regulator) of the speed loop and current loop regulator module_qrefD-axis command current i_drefAnd q-axis command current i_qrefRespectively combining the d-axis current response signal and the q-axis current response signal, and respectively outputting a q-axis voltage u through an automatic current regulator ACR (automatic current regulator) of the speed loop and current loop regulator module_qD-axis voltage u_dQ-axis voltage u_qD-axis voltage u_dObtaining voltage signals under an alpha-beta coordinate system through ipark transformation of the coordinate transformation module, obtaining six switching signals through the Space Vector Pulse Width Modulation (SVPWM) module by the voltage signals under the alpha-beta coordinate system, obtaining current signals under a two-phase static alpha-beta coordinate system through three-phase inverter circuit modules by the six switching signals, and obtaining three-phase voltages ua, ub and uc generated by the three-phase inverter circuit modules, wherein output currents ia and ib corresponding to ua and ub are converted through Clark (Clark) of the coordinate transformation module, obtaining current signals under the two-phase static alpha-beta coordinate system through park transformation of the coordinate transformation module, obtaining d-axis current response signals and q-axis current response signals under a d-q coordinate system with synchronous rotation of a rotor, and obtaining d-axis current response signals, The q-axis current response signal is a current loop feedback signal;

and three-phase voltages ua, ub and uc generated by the three-phase inverter circuit module are used as input voltages of the permanent magnet synchronous motor module, and then the sensor and the speed calculation module detect the rotating speed and the rotor position of the permanent magnet synchronous motor module and output the speed feedback value.

Compared with the prior art, the invention at least has the following beneficial effects:

(1) the initial phase detection system of the permanent magnet synchronous motor provided by the invention has small initial phase detection error;

(2) the system for detecting the initial phase of the permanent magnet synchronous motor can automatically complete detection and correction.

Drawings

FIG. 1 is a block diagram of an initial phase detection system for a PMSM according to the present invention;

FIG. 2 is a block diagram of the arcsine initial phase approximation control of the present invention;

FIG. 3 is a flow chart of the arcsine phase approximation of the present invention;

FIG. 4 is a block diagram of the binary initial phase detection control of the present invention;

fig. 5 is a flow chart of binary initial phase detection in accordance with the present invention.

The present invention is described in further detail below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

To better illustrate the invention and to facilitate the understanding of the technical solutions thereof, typical but non-limiting examples of the invention are as follows: