Title :
Interleaved High Step-Up ZVT Converter With Built-In Transformer Voltage Doubler Cell for Distributed PV Generation System
Author :
Li, Weichen ; Xiang, Xin ; Li, Chushan ; Li, Wuhua ; He, Xiangning
Author_Institution :
Nat. Prof. Lab. of Power Electron., Zhejiang Univ., Hangzhou, China
Abstract :
In this paper, the concept of built-in transformer voltage doubler cell is derived to generate an improved interleaved high step-up converter for distributed photovoltaic generation applications. The proposed built-in transformer voltage doubler cell is composed of three transformer windings, two voltage doubler diodes, and two voltage doubler capacitors. The voltage doubler capacitors are charged and discharged alternatively to double the voltage gain. The switch duty cycle and the transformer turns ratio can be employed as two controllable freedoms to lift the voltage ratio flexibly. The power device voltage stress can also be reduced to improve the circuit performance. Furthermore, the active clamp scheme is adopted to recycle the leakage energy, absorb the switch turn-off voltage spikes, and achieve zero-voltage switching (ZVS) operation for all active switches. Meanwhile, the diode reverse-recovery problem is alleviated by the leakage inductance of the built-in transformer. All these factors benefit the circuit performance improvements in the high step-up and large current applications. Finally, a 1-kW prototype with 40-380 V conversion is built and tested to demonstrate the effectiveness of the proposed converter.
Keywords :
distributed power generation; photovoltaic power systems; power transformers; zero voltage switching; ZVS; active clamp scheme; active switches; built-in transformer voltage doubler cell; circuit performance improvement; diode reverse-recovery problem; distributed PV generation system; interleaved high step-up ZVT converter; leakage energy; leakage inductance; power 1 kW; power device voltage stress; switch duty cycle; switch turn-off voltage spikes; transformer turns ratio; transformer windings; voltage 40 V to 380 V; voltage doubler capacitors; voltage doubler diodes; voltage ratio flexibly; zero-voltage switching operation; Capacitors; Clamps; Inductance; Inductors; Stress; Switches; Zero voltage switching; Active-clamp scheme; built-in transformer voltage doubler cell; high step-up; interleaved boost converter;
Journal_Title :
Power Electronics, IEEE Transactions on
DOI :
10.1109/TPEL.2012.2199771