A new control scheme for parallel-connected inverters taking into account the effect of line impedance is presented. The system presented here consists of two single-phase inverters connected in parallel. The control technique is based on instantaneous average current-sharing control that requires interconnections among inverters for information sharing. A generalized model of a single-phase parallel-connected inverter system is derived. The model incorporates the detail of the control loops that use a proportional-resonant controller, but not the switching action. The voltage- and current-controller design and parameters selection process are discussed. Adaptive gain scheduling is introduced to the controller to improve the current and power sharing for a condition, where the line impedance is different among the inverters. The simulation results show that the adaptive gain-scheduling approaches introduced improve the performance of conventional controller in terms of current and power sharing between inverters under difference line impedance condition. The experiments validate the proposed system performance.
- distribution generation (DG)
- gain scheduling
- distributed generation systems
Roslan, M. A. B., Ahmed, K., Finney, S., & Williams, B. (2011). Improved instantaneous average current-sharing control scheme for parallel-connected inverter considering line impedance impact in microgrid networks. IEEE Transactions on Power Electronics, 26(3), 702-716 . https://doi.org/10.1109/TPEL.2010.2102775