Brushless dc motor controller is often the case with tile type magnetic steel rotor poles, through the design of magnetic circuit, can obtain the trapezoidal wave air-gap flux density, the stator winding is used more focus from the whole winding, thus is trapezoidal wave induction counter electromotive force. The control of the brushless dc motor controller need location information feedback, must have a position sensor or sensorless estimation technology, constitute a self-control type of speed control system. Control the phase current ChengFangBo, try to control the inverter output voltage in accordance with the method of brushless dc motor controller with PWM control. In essence, brushless dc motor is also a kind of permanent magnet synchronous motor, speed control actually also belong to the category of variable voltage variable frequency speed regulation. Usually say that the distribution of permanent magnet synchronous motor with the stator three phase winding and the permanent magnet rotor, the magnetic circuit structure and distribution to ensure induction emf waveform is sine, plus the stator voltage and current are also should be sine wave, typically by ac variable pressure transducer. Permanent magnet synchronous motor control system often USES self-control type, also need to position feedback information, can use vector control (Field oriented control)Or direct torque control of advanced control strategy. General brushless dc motor controller design, the air-gap magnetic field is a square wave (Trapezoidal wave)And part of the ceiling as flat as possible, so that the logarithmic choice generally taken the integer slot 4 pole 12 slot, for example, concentrated winding and magnetic steel is generally concentric rings of fan-shaped radial magnetic. And general Hall sensor to detect the position and speed, driving mode is generally six-step square wave drive, for special occasions position requirements is not very high. Air gap is the permanent magnet synchronous sine wave, as sinusoidal as possible, so a logarithmic fractional slot winding on choice, such as 4 15 slots, chamfer of 10 extremely 12, magnetic steel is bread, the magnetization, parallel sensor type general configuration of incremental encoder, rotating transformer, absolute encoder, etc. Typically driven by sine wave driven I way, such as FOC algorithm, etc. Used for the servo. From the internal structure, sensor, actuator, and applications. The motor controller can be used interchangeably, but can make the performance degradation. For most of the air gap waveform between permanent magnet motor controller, basically see driving mode. Permanent magnet brushless dc motor controller speed can be changed. Permanent magnet synchronous motor controller need to use special drive to change, such as three crystal S3000B servo drives.
