Control of PV battery hybrid system using Cascaded H Bridge converter

The Cascaded H Bridge (CHB) is a superior topology to integrate PV panels into the grid. However, due to the internal uncertainty power supply of renewable sources, it is difficult to arrange the PV CHB inverter to meet the system scheduling requirement. To overcome this limitation, a CHB inverter topology with both PV arrays and energy storage elements is proposed in this paper. In order to simplify the system control complexity, a two-layer hierarchical control is also developed. The lower layer is responsible for system PQ control and distribution among each HB, and the upper layer decides power dispatching and generate power references for each H-bridge (HB). With the proposed approach, a hybrid PV and battery system can be coordinated controlled with only a single power conversion stage. Verification results are provided to validate the performance of the proposed system.