A Non-isolated High Step-up DC/DC Converter with Low EMI and Voltage Stress for Renewable Energy Applications

Abstract

-In this paper, a high step-up DC-DC PWM converter with continuous input current and low voltage stress is presented for renewable energy application. The proposed converter is composed of a boost converter integrated with an auxiliary step-up circuit. The auxiliary circuit uses an additional coupled inductor and a balancing capacitor with voltage doubler and switching capacitor technique to achieve high step-up voltage gain with an appropriate switch duty cycle. The switched capacitors are charged in parallel and discharged in series by the coupled inductor, stacking on the output capacitor. In the proposed converter, the voltage stress on the main switch is clamped, so a low voltage switch with low ON resistance can be used to reduce the conduction loss which results in the efficiency improvement. A detailed discussion on the operating principle and steady-state analyses are presented in the paper. To justify the theoretical analysis, experimental results of a 200W 40/400V prototype is presented. In addition, the conducted electromagnetic emissions are measured which shows a good EMC performance.

The Study of the Operational Characteristic of Interleaved Boost Converter with Modified Coupled Inductor

“…Initially, the time waveforms on the inductors were investigated due to verification of the existence of AC magnetic flux of the L 3 , which serves for the core demagnetization. Finally, the focus was given on the evaluation of the efficiency and voltage gain performance for the selected duty cycle values [39][40][41][42]. At this point the turns ratio between L 1 and L 2 is equal to 1:1, while the turns ratio between L 1 and L 3 and L 2 and L 3 is 1:1,7.…”