Untitled Document
Untitled Document
> Archives > To Be Published
Recently Accepted Papers
Mechanism Analysis and Stabilization of Three-Phase Grid-Inverter Systems Considering Frequency Coupling
Guoning Wang, Xiong Du, Ying Shi, Heng-Ming Tai, and Yongliang Ji
Abstract Frequency coupling in the phase domain is a recently reported phenomenon for phase locked loop (PLL) based three-phase grid-inverter systems. This paper investigates the mechanism and stabilization method for the frequency coupling to the stability of grid-inverter systems. Self and accompanying admittance models are employed to represent the frequency coupling characteristics of the inverter, and a small signal equivalent circuit of a grid-inverter system is set up to reveal the mechanism of the frequency coupling to the system stability. The analysis reveals that the equivalent inverter admittance is changed due to the frequency coupling of the inverter, and the system stability is affected. In the end, retuning the bandwidth of the phase locked loop is presented to stabilize the three-phase grid-inverter system. Experimental results are given to verify the analysis and the stabilization scheme.
Keyword Admittance, Frequency coupling, Grid-connected inverter, impedance, Stability
Untitled Document