耦合电感与开关电容集成的高升压增益变换器

High step-up converter integrating the coupled-inductor and the switched-capacitor

针对新能源发电单元并网时输出电压低的问题,提出了一种新型的高升压增益非隔离变换器。采用脉宽调制策略,研究了耦合电感、开关电容与传统boost升压变换器的结合策略,实现了变换器(2 n+1)/(1-2 D)的输出电压增益。所提拓扑将开关电容串进励磁电感的充电回路,使单个耦合电感倍压单元的升压系数提升为2 n;因开关电容与滤波电感串联,解决了开关过程中冲击电流的问题;耦合电感中寄生漏感的能量由开关电容所吸收,避免了电压尖峰问题并降低了开关管的电压应力。分析并讨论了电路的工作原理、稳态特性与功率损耗,设计了200 W 20 V/200 V的实验样机验证理论分析的正确性与可行性。

To solve the problem of the low output voltage of the new energy generation unit,a non-isolated high step-up converter is proposed.Pulse width modulation was adopted for the topology.The combination of switched-capacitor,coupled-inductor and the traditional boost converter was studied to enlarge the voltage conversion ratio to(2 n+1)/(1-2 D).The switched-capacitor was added to the magnetic inductor’s charging circuit.Thus,the boost coefficient of one coupled-inductor voltage multiplier was increased to 2 n.The problem of the inrush current was solved due to the filter inductor in the circuit.Moreover,energy stored in the parasitic leakage inductor of coupled-inductor was recycled by the switched-capacitor,solving the voltage spike and reducing the voltage stress of the switches.The working principle,the steady-state characteristics and the loss were analyzed.Finally,the experimental results based on a 200 W 20 V to 200 V prototype verify the correctness and the feasibility of the theory.