A transient reactive current compensation for load-side converter of BDFG in stand-alone operation

摘要

In this paper, a transient control method is proposed to compensate the reactive currents when the resistive-inductive load is suddenly connected to the power winding of the brushless doubly-fed generator (BDFG). Under stand-alone situation, the waveform of stator power winding voltage is strongly affected because of reactive power component of load. To tackle this problem, the load-side converter (LSC) works as a static var generator by injecting a reactive current at the point of common coupling (PCC) to compensate the reactive load. Hence, the LSC controller must determine the instantaneous value of the reference compensation current, according to the reactive component of the load current. This paper analyzes the transient-state of the load current when the load is suddenly connected to the BDFG, and proposes a compensation algorithm which has a good transient-state performance at the PCC. In addition, an improved reactive load current detection which does not rely on phase-locked loops is applied in this paper and the moving average (MVA) filter instead of traditional low-pass filter (LPF) is also used. So the control algorithm is simple and do not need more computation. The correctness of the proposed method is demonstrated by simulations and experiments.