Wide Range Series Resonant DC-DC Converter with a Reduced Component Count and Capacitor Voltage Stress for Distributed Generation

This paper proposes a galvanically isolated dc-dc converter that can regulate the input voltage in a wide range. It is based on the series resonance dc-dc converter (SRC) topology and a novel boost rectifier. The proposed topology has a smaller number of semiconductors than its SRC-based existing topologies employing an ac-switch in the boost rectifier. The proposed dc-dc converter comprises only two diodes and one switch at the output side, while the existing solutions use two switches and two diodes to step up the voltage. The proposed converter boosts the input voltage within a single boosting interval in the positive half-cycle of the switching period. In addition, the resonant current in the negative half-cycle is sinusoidal, which could enhance the converter efficiency. The resonant capacitor voltage is clamped at the level of the output voltage. Therefore, the voltage stress of the capacitor could significantly reduce at various input voltage and power levels. This makes it perfect for distributed generation applications such as photovoltaics with wide variations of input voltage and power. The converter operates at the fixed switching frequency close to the resonance frequency to obtain the maximum efficiency at the nominal input voltage. The zero-voltage switching (ZVS) feature is achieved in the primary semiconductors, while the diodes in the output-side rectifier turn off at nearly zero current switching. The mathematical model and design guidelines of the proposed converter are discussed in the paper. The experimental results confirmed the theoretical analysis based on a 300 W prototype. The maximum efficiency of the converter was 96.8% at the nominal input voltage, and the converter has achieved a wider input voltage regulation range than that with the boosting cell comprising an ac-switch.

Pengoptimalan Kinerja Pengereman Regeneratif Motor BLDC menggunakan Cascaded Boost Converter

ABSTRAKMesin Brushless Dircet Current (BLDC) digunakan pada kendaraan listrik karena memiliki torsi yang besar dan memungkinkan untuk pengereman regeneratif. Pengereman regeneratif dirancang agar kendaraan listrik memiliki jarak tempuh yang lebih panjang. Pada saat pengereman, konverter bidirectional dioperasikan menjadi boost rectifier agar energi dapat berpindah ke baterai. Boost rectifier memiliki gain yang rendah, sehingga pengiriman daya ke baterai kurang optimal. Pada penelitian ini ditambahkan chopper kedua yang memiliki gain tinggi agar pengiriman daya lebih optimal. Metode modulasi lebar pulsa yang dibangkitkan mikrokontrol dsPIC30f4012 digunakan untuk mengendalikan saklar (IRFP 460) pada konverter. Verifikasi menggunakan perangkat keras telah dilakukan untuk mendukung penelitian ini. Hasil percobaan pada duty cycle 0,8 dapat dihasilkan arus pada baterai sebesar 0,25 A dan kecepatan berkurang menjadi 663 rpm.Kata kunci: BLDC, Pengereman regeneratif, Boost rectifier, chopper, dsPIC30f4012 ABSTRACTBrushless direct current (BLDC) machine is suitable to be implemented in electric vehicle since it can provide high torque and is capable to do regenerative braking. For electric vehicle applications, the regenerative braking is needed to make such vehicle can travel longer distance. For making the machine current can flow into the battery, the bidirectional converter will be operated as a boost rectifier. The boost rectifier produced a low gain so that the second chopper with a high gain is required. The pulse width modulation (PWM) method was used to control each switch (IRFP 460) using a dsPIC30F4012 microcontroller. A verification with experimental work was done. Based on the result, with 0.8 duty cycle can produced a 0.2 A battery current also and speed reduced to 663 rpm.Keywords: BLDC, Regenerative braking, Boost rectifier, chopper, dsPIC30f4012