Speed and power factor controller for AC adjustable speed drives

The speed and power factor of an adjustable speed slip power recovery drive are controlled in order to optimize the operation. This is accomplished by means of a variable-voltage-variable-frequencies power converter. The function of the digital controller of the power converter is to provide the online speed and power factor regulation. The hardware and software are described. This scheme has an accurate voltage output with very low harmonic content, a good resolution for the phase angle regulation and the frequency control with the possibility of range extension.<
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