Trapezoidal wave commutation

Control of brushless dc motor is one of the most simple way is the so-called "trapezoidal wave type" commutation. In this scheme, we only control a pair of the current in the motor coil, and the third line generator set spare parts circle has been in contact with the power supply is not in the circuit. Installed in the motor internal hole signal once every 60 degree Angle detection, and the detected results through digital signal feedback to the controller electric vehicle motor part of the motor. Because in the case of trapezoidal wave commutation, only two sets of coil motor is connected with the same current, and the third group of coil current Induction motor is zero, so this way of testing the motor rotation can only be detected in a lap six direction of current vector. In the process of motor rotation, the motor current once every 60 degree change, so each current vector only within the scope of wholesalemotor.blogspot.com current calibration about 30 degrees. The current waveform from zero step jump to a positive maximum current, and then to zero, then into a negative maximum current. In this case, the motor current in the six regional jump regularly, make motor can approximate running smoothly.