Control strategy for PV inverter under unbalanced grid voltage

Abstract

To enhance the operation performance of the PV inverter under unbalanced grid voltage, this paper proposes a control strategy, which is based on negative sequence voltage feed forward, to make the output current of the inverter balanced and sinusoidal. To separate the positive and negative sequence voltage quickly and accurately, the paper proposes a scheme based on the second order generalized integrator(SOGI). The experimental results validate the effectiveness of the proposed method. Finally, the control strategy, which is validated effectively, is simulated and analyzed by PSCAD simulation software.

Keywords

• negative sequence voltage feed forward
• unbalanced grid voltage
• PV inverter
• PSCAD/EMTDC