The permanent magnet synchronous motor (PMSM) is a high-performance, high-efficiency motor that is widely used in industrial automation, robotics, electric vehicles and other fields. In order to achieve precise control of permanent magnet synchronous motors, AC servo control systems are usually used. TOPCHIP ELECTRONICS, a spot supplier of electronic components, will introduce to you commonly used algorithms for permanent magnet synchronous motor AC servo control systems, including magnetic field oriented control, space vector modulation, PID control, etc.
1. Field Oriented Control (FOC)
Field-oriented control is a commonly used permanent magnet synchronous motor control algorithm. Its principle is to maintain the electromagnetic field and rotor magnetic field of the motor on the same axis by measuring the stator current and rotor position of the motor to achieve precise control of the motor. Magnetic field oriented control mainly includes the following steps:
-Coordinate transformation: Convert the three-phase stator current of the motor into the dq-axis current in the αβ coordinate system.
-Rotor position estimation: Measuring the rotor position of the motor through an encoder or sensor is used to calculate the rotor magnetic field position of the motor.
-Field oriented control: Control the direction of the motor's magnetic field according to the rotor position and dq-axis current, so that the electromagnetic field of the motor and the rotor magnetic field are kept on the same axis.
The field-oriented control algorithm has the characteristics of fast response speed and high control accuracy, and is suitable for high-performance control of permanent magnet synchronous motors.
2. Space vector modulation (SVM)
Space vector modulation is a commonly used permanent magnet synchronous motor control algorithm. Its principle is to control the stator voltage of the motor to keep the motor's magnetic field and the rotor magnetic field synchronized to achieve precise control of the motor. Space vector modulation mainly includes the following steps:
-Coordinate transformation: Convert the control voltage into the dq-axis voltage in the αβ coordinate system.
-Space vector generation: Generate the space vector of the control voltage based on the rotor position and dq-axis voltage.
-PWM waveform generation: Generate PWM waveform according to the space vector, control the three-phase voltage output by the inverter, and drive the motor to move.
The space vector modulation algorithm has the characteristics of high control accuracy and small output voltage ripple, and is suitable for high-efficiency control of permanent magnet synchronous motors.
3. PID control
PID control is a commonly used permanent magnet synchronous motor control algorithm. Its principle is to adjust the control parameters of the motor by comparing the actual operating state of the motor with the expected operating state, so that the operating state of the motor reaches the expected value quickly and stably. PID control mainly includes the following parts:
-Proportional control (P): Adjust the output voltage of the motor according to the size of the error, so that the error quickly converges toward the desired value.
-Integral control (I): Adjust the output voltage of the motor according to the accumulation of error, so that the error can converge to the desired value stably in the long term.
- Differential control (D): Adjust the output voltage of the motor according to the change rate of the error, so that the change rate of the error can quickly and stably reach the desired value.
The PID control algorithm has the characteristics of simple implementation and convenient adjustment, and is suitable for stable and accurate control of permanent magnet synchronous motors.
4. Advanced control algorithm
In addition to the above-mentioned basic control algorithms, there are also some advanced control algorithms that can be used to control permanent magnet synchronous motors, such as model predictive control (MPC), adaptive control, neural network control, etc. These control algorithms can be selected and used in actual applications according to specific control needs and performance requirements to achieve more complex and advanced control functions.
The permanent magnet synchronous motor AC servo control system is a commonly used motor control system. Its core algorithms include magnetic field oriented control, space vector modulation, PID control, etc. These algorithms have their own characteristics and advantages and can be selected and used according to specific control needs and performance requirements to achieve precise control and high-performance operation of permanent magnet synchronous motors.