Resonance Suppression Method for the Multi-inverter System Based on Single-inverter Impedance Reshaping

This paper investigates the problem of resonance suppression for systems composed of inverters with different parameters. Grid voltage proportional feedforward control enhances the ability to suppress grid background harmonics, but it leads to weaker adaptation to the weak grid. However, most of the existing improvement methods require reshaping all the inverters to achieve system stability. In this paper, a multi-inverter system model is built to analyze the main influencing factors of resonance and propose reshaping objectives. According to the reshaping objective, the impedance of a particular inverter is reshaped. This method improves not only the stability of the single inverter but also the stability of the system. Finally, the correctness of the relevant conclusions is verified by simulation results.