Analysis and implementation of a high step‐up converter for fuel cell power‐generation systems

Abstract

This paper presents a high step-up converter, which utilizes a three-winding coupled inductor and a rectified voltage-doubler circuit to obtain high step-up gain for fuel cells. The proposed converter functions as an active-clamp circuit, which relieves large voltage spikes across the power switches. Thus, power switches with low-voltage-rated can be utilized to reduce conduction losses and circuit cost. Energy stored in leakage inductances of the coupled inductor is recycled to the output terminal, resulting in efficiency improvements. In addition, the coupled inductor in the presented converter can also have extra windings in order to achieve higher voltage gain. Finally, a prototype circuit with an input voltage of 60 V and an output voltage of 380 V is developed for a 1000 W-rated fuel cell power-generation system to validate its performance, and experimental waveforms and measured efficiency under different input voltages and output power level are demonstrated.

A new topology for nonisolated multiport zero voltage switching dc‐dc converter

“…In addition, in conventional hybrid systems of PV arrays and battery, there must be 2 converters used that would increase the size and cost of the unit, but multiport converters are able to provide better performance with less number of components. [9][10][11][12] Some multiport converters are presented in previous studies. 2 There are several multiport dc-dc converters presented in recent years.…”

A new non‐isolated free ripple input current bidirectional DC‐DC converter with capability of zero voltage switching

“…Furthermore, in these converters, the switches operate under hard switching. The power losses of the nonisolated high voltage conversion ratio bidirectional converters are lower than the isolated converters . In Sedaghati et al, a dual active bridge dc‐dc converter is presented.…”

“…The power losses of the nonisolated high voltage conversion ratio bidirectional converters are lower than the isolated converters. [11][12][13][14] In Sedaghati et al, 15 a dual active bridge dc-dc converter is presented. The main advantages of this converter are bidirectional power flow and ZVS characteristics.…”

Analysis and implementation of a step–up power converter with input current ripple cancelation

“…One particular feature of these converters is that the output voltage is taken from a single capacitor, due to the cascade connection of both converters. Converters presented in Figure (left) can directly charge the inductors, besides the output voltage is obtained by adding several capacitor voltages, similar to those presented in other studies . In both configurations, a common feature is that the input current is drawn in such a way that the ripples are canceled out each other.…”

“…5,6 The employment of multiplier-type converters to achieve, ultimately, a higher voltage gain, has been proposed, as well. 7 A high-gain converter is suitable for cell fuel 8 and pv applications 5,7 where the low dc voltage is available, and the efficiency of the converter takes relevant importance. 9 The other essential feature sought is the quality of the input current, which is related to the ripple magnitude.…”