A Novel Energy Management Control Technique for PV-Battery System in DC Microgrids

This paper presents a new energy management control technique for PV-Battery system used in DC microgrids. The proposed control technique is performed based on a droop control algorithm that maintains DC-bus voltage in a desirable and required range adaptively. Tightly Regulating the bus voltage In the islanded mode of operation is very challenging. However, the proposed control method by introducing a nonlinear droop profile with four adaptive parameters shows its superiority. Adaptive parameters determined by the non-linear optimal algorithms. Tightly regulating the DC bus voltage during extensive changes in demand loads/sources within a DC Micro Grid is the responsibility of the adaptive parameters. Stability of the proposed method in the whole system for a very broad range of operating conditions are proved. Simulation results along with the experimental results verify the feasibility of the proposed approach while demonstrate its superior performance compared to the conventional control method

Half-Bridge Full-Bridge AC–DC Resonant Converter for Bi-Directional EV Charger

A new topology and controller based on single-stage AC-DC resonant converter, without Electrolytic capacitors (E-cap), for bi-directional EV battery chargers is proposed in this paper. The topology is a Half-Bridge (HB)-Full-Bridge (FB) resonant converter with MOSFET’s connected in series and in opposite direction on its AC Half-Bridge side plus an active filter on the DC-side. No use of E-cap makes the converter more reliable. The establishment of an appropriate control scheme enables a wide range of active and reactive power control under different AC and DC voltage levels. The proposed controller not only facilitates the converter to operate under Zero Voltage Switching (ZVS) for all switching instants, but also it minimizes the conduction loss. ZVS allows higher switching frequencies and together with reduction in conduction losses improves the efficiency. The active filter is controlled to absorb the low frequency current ripple and prevent it from going to battery. Charging the battery with reduced low frequency ripple prevents extra heat production and increases the lifespan of the battery. Mathematical analysis, simulation and experimental results are presented