Some fan and pump applications require that the drive has to start into naturally forward rotating load without stopping the load first. A fan used in the air conditioner outdoor unit, for example, is one of these applications. A fan needs to be started at any naturally rotating forward speed or from standstill and brought to the desired speed. When it naturally rotates in reverse direction, the drive must transition from reverse to forward rotation in a drive system without regeneration capability. With the traditional fan drive, which includes a Hall sensor to detect the rotor position of PM motor, this is a relatively simple task since excitation angle and speed of the controller at startup can be synchronized to the angle and speed at which the fan naturally rotates. In case of the drive without the position sensor, this task is more elaborate due to the fact that speed reversal is required without position sensing.
This paper describes a new algorithm for starting a PM motor drive into the forward and reverse naturally rotating load, where drive system does not have a regeneration capability and has only one current feedback sensor installed in the dc bus link. The algorithm is implemented on a chip belonging to a new motion controller family, which has been recently introduced by International Rectifier. The chip features a hardware computation engine, called Motion Control Engine (MCE), for sinusoidal sensorless PM motor control. Experimental results are included.
| Filename: | T5-305.pdf |
| Filesize: | 835.6 KB |
