A Cascaded High Step-Up DC–DC Converter With Single Switch for Microsource Applications

Abstract

This paper proposes a new high step-up DC-DC converter designed especially for regulating the DC interface between various microsources and a DC-AC inverter to electricity grid. The figuration of proposed converter is a quadratic boost converter with the coupled inductor in the second boost converter. The converter achieves high step-up voltage gain with appropriate duty ratio and low voltage stress on the power switch. Additionally, the energy stored in the leakage inductor of the coupled-inductor can be recycled to the output capacitor. The operating principles and steady-state analyses of continuous-conduction mode and boundary-conduction mode are discussed in detail. To verify the performance of the proposed converter, a 280W prototype sample is implemented with an input-voltage range of 20 ~ 40 V and output voltage of up to 400 V. The upmost efficiency of 93.3% is reached with high line input; on the other hand, the full-load efficiency remains at 89.3% during low line input.

Novel High Step-Up DC/DC Converter Structure Using a Coupled Inductor with Minimal Voltage Stress on the Main Switch

“…Thus, its voltage is zero. The difference between the experimental efficiencies of the proposed converter and the converters presented in [32], [24], [33], and [34] for different output powers is shown in Fig. 15.…”

“…By substituting Equations (28), (33), and (34) into Equation (29), the voltage gain is obtained as follows: [24], [25], and [32] in CCM operation under…”

“…15. Measured efficiency of the proposed converter compared with that of converters presented in [32], [24], [33], and [34].…”

A Novel Boost Conversion with High Voltage Ratio

“…The literature [9][10][11] proposed a cascade high gain converter, in the post-converter using coupling inductance technology, can effectively achieve the converter's high gain characteristics [12][13] , but the converter cascade will lead to low efficiency.…”

X-Y converter family: A new breed of buck boost converter for high step-up renewable energy applications

“…Several industries are required to design a Cascaded Boost Converter (CBC) which is the most complex part and quite hard to encapsulate [20,21]. In addition to that, high ripple current and losses prove to be obstacles to attain the high conversion ratio and efficiency [26,27]. Quadratic Boost converter (QBC) is proposed to obtain high voltage gain by just using a single switch.…”