Bi-Directional Power Management Over DG Battery-Less Hybrid MicroGrids

This Research proposes the use of 3φ power converter setup with suitable controller, for power flow management over a hybrid micro-grid, without need to any permanent storage systems on the DC bus to counteract their high cost, complexity of design and integration. Such proposed system is capable of serving low voltage residential and commercial loads, where there would be an availability of renewable energy sources and possible DC loads. Bidirectional power transmission is achieved between AC and DC buses through a 3φ bi-directional converter whose primary objective is to maintain a constant DC bus voltage with respect to DC sources or loads change. A PI controller is utilized to stabilize the reference DC bus voltage by varying the reference AC grid side current that is controlled by a hysteresis controller. Also automatic coupling of a 3φ synchronous generator to the infinite bus AC grid has been discussed and studied, analytically and practically as a case study, to deepen the concept of distributed generation. The experimental set has been tested for contributing to the AC grid, with direct active and reactive power control. Matlab and Practical results have been discussed.