Design and implementation of high efficient dual control modular resonant converter for DC microgrid

Abstract

A modular structured 12-kW resonant converter with effective zero voltage switching (ZVS) is proposed to integrate renewable energy lower voltage source to the microgrid. In this study, duty cycle control is adopted until ZVS fails and thereafter, sequential and parallel adjustment of duty cycle and the switching frequency is proposed for effective output voltage regulation. The proposed control logic ensures ZVS and output voltage regulation over wide load range even at very light loads compared to conventional control methods. Further, it maintains very high system efficiency with narrow range of frequency operation. Hence, it is easy to implement using a conventional digital controller. To minimise ripple current, each of the four converters is provided with 90° phase delayed gate pulses under the proposed control scheme. This study presents an optimal design of the tank circuit elements assimilating high permeable powder cores to reduce magnetic loss and operation with IGBT switches at an optimum point to reduce conduction loss for enhanced system efficiency. A 12-kW, 400-1600 V developed prototype is tested and experimental results are discussed.

Design and Convergence Analysis of an Improved Droop Controller With Adaptive Virtual Impedance

“…With the development of alternative energy technologies, the application of distributed generators (DGs) has become more and more widespread. The microgrid system can incorporate different types of alternative energy sources and satisfy customer demands with high-quality electrical energy [1]. In recent years, the research on microgrid has attracted widespread attentions from the electric power industry and academia [2]- [3].…”