Investigation on Start and Cut-in of the Multi-function Flexible Power Conditioners

A multi-functional flexible power conditioner (FPC) can be considered to be a double-fed induction motor (DFIM) with very large rotating inertia and without mechanical load. It can regulate active and reactive power separately and rapidly. Hence it can be applied to improve stability and quality of power systems operation. The start and cut-in method of FPC is investigated in this paper. Based on the characteristics of FPC, two starting methods called serial rotor resistance start and frequency conversion start are selected and analyzed in details. Both of two methods adopt direct cut-in mode. Simulation results show that the latter method is a very good starting method for FPC because it needs neither switching of control strategy nor additional subsidiary starting equipment. The frequency conversion start can also be applied to DFIM. This work is jointly supported by Special Fund of the National Basic Research Program of China (No. 2004CB217906) and National Natural Science Foundation of China (No. 50507006).