Design and implementation of a high‐efficiency bidirectional DC‐DC Converter for DC micro‐grid system applications

Abstract

This paper studies the design and implementation of a non-isolated dual-half-bridge bidirectional DC-DC converter for DC micro-grid system applications. High efficiency can be achieved under wide-range load variations by the zero-voltage-switching features and an adaptive phase-shift control method. A three-stage charging scheme is designed to meet the fast-charging demand and prolong the lifetime of LiFePO 4 batteries. A digital-signal-processing control IC is used to realize the power flow control, DC-bus voltage regulation, and battery charging/ discharging of the studied bidirectional DC-DC converter. Finally, a 10 kW prototype converter with Enhanced Controller Area Network communication function is built and tested for micro-grid system applications. A light-load efficiency over 96% and a rated-load efficiency over 98% can be achieved.State 5 (t 4 < t < t 5 ): At t 4 , Q A is turned off. Inductor current charges the parasitic capacitance of Q A and discharges the parasitic capacitance of Q B until the voltage across Q A reaches to V Bat and the voltage across Q B reaches to zero, then body diode of Q B conducts. Figure 4. Equivalent circuits of different switching states. 1142 H.-J. CHIU ET AL.

Efficiency of magnetic coupled boost DC‐DC converters mainly dedicated to renewable energy systems: influence of the coupling factor

“…Indeed, the simulation of this mode clearly shows that I c starts exactly from MAGNETIC COUPLED DC-DC CONVERTERS: INFLUENCE OF THE COUPLING FACTOR À I L1max and then increases up to zero at the end of this mode, at time t 2 . Thus, we must recall preliminary considerations described by the previous general equation of this mode, Equation (22), and defined the expression of α 2 as follows: Thus, we must recall preliminary considerations described by the previous general equation of this mode, Equation (22), and defined the expression of α 2 as follows:…”

“…In this study, the generalized concepts of system energy parameters of DC-DC converters are introduced and applied to the transient analysis. As examples, one can note high-intensity discharge lamp ballasts used in automotive head lamps or the front-end converter with dual inputs (a main AC grid and battery-based DC power supply) developed to substitute the common but complex uninterruptible power supply in computer and telecommunication industries [7].Many research activities around the world are focused to the study and optimizations of boost converters [8][9][10][11][12][13]; some papers discuss the circuit theory aspects or practical realizations [14][15][16]; others are dedicated to the modeling of the DC-DC converters [17][18][19][20]; others are mainly oriented to specific applications such as renewable energy systems that concern us in this article [5,21,22]. The simulation results are compared with those of the behavioral study, deduced from the model pointing out the large influence of the coupling factor value on the global behavior and mainly on the value of the recovery voltage, in all the various parts of the switching cycle.…”

“…Many research activities around the world are focused to the study and optimizations of boost converters [8][9][10][11][12][13]; some papers discuss the circuit theory aspects or practical realizations [14][15][16]; others are dedicated to the modeling of the DC-DC converters [17][18][19][20]; others are mainly oriented to specific applications such as renewable energy systems that concern us in this article [5,21,22]. One can also refer to a review proposed by Kazimierczuk in a book describing the recent state-of-art of Pulse Width Modulation (PWM) DC-DC power converters [23].…”

Modeling, control, and implementation of the soft switching dc-dc converter for battery charging/discharging applications

“…However, the conventional non isolated bidirectional dc-dc converters are suffered from large switching losses, the long reverse recovery time of anti-parallel diodes and resonant current sensing problem. Adaptive phase shift (PS) techniques based converters are introduced to reduce switching losses [15]. Although a look up table is developed to control the auxiliary switch, which creates resonant current trouble.…”

Analysis and Controller Design of a Universal Bidirectional DC-DC Converter

“…Moreover, they are all isolated type bidirectional DC-DC converters [29]. In [30,31], a novel low loss modulation strategy with simple circuit configuration is proposed. The advantages of these systems include high efficiency, no additional cost and a simple structure.…”