The basic principles of the permanent magnet BLDC motor

We talk about one type of permanent magnet bldc motor for electric bike. It’s a bldc electric bike motor , sometimes we also call it brushless dc hub motor .
The permanent magnet bldc motor and the bldc motor driver is a typical product for e-bike recently.
Generally the electric bike motor ’s stator windings is made of a three phase star connection, with the three-phase asynchronous AC bldc motor is very similar. The hub motor rotor has been magnetized permanent magnet, in order to detect the polarity of the hub motor, there are three halls sensors on the rotor.
The bldc motor driver is made by the power electronic devices and integrated circuits, its function is to receive electric bike motor ’s start, stop and brake signal so that control the hub motor to start, stop and brake; receive the position sensor signals and reversing signal, used to control the inverse power tube change the bridge off to produce a continuous torque; receive the speed command and speed feedback signal used to control and adjust the speed; provide protection and display
The main circuit is a typical voltage-type AC – DC – AC circuit, inverter and other pieces of alternating square wave frequency of 5-26KHZ modulation wave symmetry.
Permanent magnet NS alternating exchange, the position sensor phase difference of 120 ° U, V, W, square wave, combined with the six-state encoding signal forward / reverse signal generator: 101,100,110,010,011,001, through processing logic components to produce conduction of T1-T4, T1-T6 turns on, the T3-T6 conduction, T3-T2 turn-on, turn-T5-T2, T5,-T4 conduction, which means that the DC bus voltage is incremented A + B-, A + C-, B + C-, B + A-, C + A-, C + B-, so that the rotor turned a pair of NS pole, T1-T6 power tube fixed into six states followed by conduction. Each state, only two phase windings are energized in order to change a state, the axis of the magnetic field generated by the stator windings 60 ° electrical angle of rotation in space, the rotor follows the stator magnetic field rotation is equivalent to the space of 60 ° electrical angle position, the rotor in a new location so the position sensor U, V, W to produce a new set of coding according to the agreement, the new coding and changed the power tube combination of conduction, the magnetic field generated by the stator winding shaft forward 60 ° electrical angle, and so on, permanent magnet electric bike motor produces continuous torque, drag the load for a continuous rotation. Permanent magnet DC motor commutation is itself, rather than forced by the inverter commutation, also known as controlled synchronous hub motor.
Hub motor, bldc motor, electric bike motor supplier: Leaf Motor Technology Co.,Ltd
Website:https://www.leafmotor.com