Voltage Unbalance Mechanism Research with Large-scale Wind Power Integration

In weak power system with large-scale wind power integration, three-phase unbalance occurs frequently. Voltage unbalance may lead to more losses and heat to power system and deteriorate operation performance of wind turbine generators. In this paper, the voltage unbalance mechanism is investigated based on a field test case in North China. The technical features of three-phase voltage are extracted from field test data. An equivalent three-phase model is proposed, based on which, the theoretical derivation of voltage unbalance factor(VUF) is investigated and impacts of wind power on VUF are analyzed. Finally, the field practice model is built on matlab/simulink platform and the simulated three-phase voltage and VUF are compared with field test data.