A unified bifurcation control strategy for voltage source inverter

Abstract

There exist fast scale and slow scale nonlinear dynamic behaviors in the voltage source inverter. Period doubling bifurcation and low-frequency oscillation instability phenomena are investigated. A unified bifurcation control strategy based on frequency-domain transfer function is proposed to suppress the fast-scale and slow-scale instabilities under the guarantee of the inverter's good dynamic and static performance. The stability boundary of the inverter is greatly expanded with the help of the controller. Harmonic balance method and small-signal averaged model are used to verify the effectiveness of the proposed control method when it is used to suppress the period-doubling bifurcation and the low-frequency oscillation, the stability domain border is also derived with the help of the analysis method. Theoretical analysis and simulation results show that the proposed control strategy is correct and feasible.