This paper presents the design and implementation of an energy management system (EMS) with fuzzy control for a DC micro-grid system. Modeling, analysis and control of distributed power sources and energy storage devices with MATLAB/Simulink are proposed, and the integrated monitoring energy management system (EMS) is implemented with LabVIEW. To improve the life cycle of the battery, fuzzy control manages the desired state of charge (SOC). The RS-485/ZigBee network has been designed to control the operating mode and to monitor the values of all subsystems in the DC micro-grid system.

A bidirectional isolated full-bridge dc-dc converter with a conversion ratio around nine times, soft start-up, and soft-switching features for battery charging/discharging is proposed in this paper. The converter is equipped with an active flyback and two passive capacitor-diode snubbers, which can reduce voltage and current spikes and reduce voltage and current stresses, while it can achieve near zero-voltage-switching and zero-current-switching soft-switching features. In this paper, the operational principle of the proposed converter is first described, and its analysis and design are then presented. A 1.5-kW prototype with a low-side voltage of 48 V and a high-side voltage of 360 V has been implemented, from which measured results have verified the discussed features.

In this paper, the compensation of voltage sags and swells using a dynamic voltage restorer (DVR) based on a bi-directional AC/AC converter is presented for stabilizing single-phase AC line voltage. The H-bridge AC/AC converter with bi-directional switches and without bulk capacitor is adopted as the power topology of the proposed system. The proposed novel topology of DVR is adopted to compensate both voltage sag and swell conditions. Additionally, the power factor is closed to unity because a bulk capacitor is not required. The inner and outer loop control is proposed to improve the response with gain scaling; gain control is adopted to reduce the overshoot. Finally, a 2 kVA prototype has been implemented to verify the performance and accuracy of the control method for the DVR system. The peak efficiency of the system is up to 94%, and it can compensate 50% voltage swells and 25% voltage sags.

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The objective of this paper is to design and implement a phase-control dimming electronic ballast system which consists of a phase controller, a boost converter, a half-bridge inverter and a system controller. The firing angle of the phase controller is sensed as a reference to adjust the output voltage of the converter and switching frequency of the inverter to achieve a dimming feature. The designed system can solve the practical installation problem of the system. Hardware measurements have been presented to verify the proposed method in this paper.