A voltage-error-sharing scheme for parallel-inverter systems to improve weighting current distribution and dynamic response

This paper proposes a voltage- and current-error-sharing scheme for parallel-inverter systems to improve weighting current distribution and dynamic response. The proposed scheme is based on the conventional current weighting distribution control (CWDC) and weighting the output voltage error signal according to the power ratings of the inverters to distribute current signals to each inverter module. Weighting current controllers are also designed according to the power ratings of the inverters. With the proposed scheme, a new duty-ratio control signal for the next switching cycle can be updated more precisely; thus, current distribution among inverters with different power ratings will be more precise and transient time under a step-load change can be shortened. Simulated and experimental results from a three-inverter system with identical or different power ratings and with linear or nonlinear loads have demonstrated the aforementioned performance