中文摘要：

针对级联无桥变换器不能实现单位功率因数运行且功率因数角会随着负载加重而变大的问题，提出了一种新型的基于无桥和全控H桥混合级联拓扑结构的整流器。阐述了该拓扑的基本工作原理，建立了直流稳态的数学模型，分析了拓扑的功率因数范围，计算了电路参数和负载比的取值范围，制定出带有均压环的双闭环控制策略，最后通过实验验证了这一拓扑的可行性和正确性，实现了单位功率因数整流和级联模块均压的预期目的。

英文摘要：

To solve the problem that cascaded bridgeless converter can not realize unit power factor working condition and the power factor angles get bigger with heavier load, a new hybrid cascaded multi-level rectifier is presented, which includes two stages：the cascaded bridgeless converter and the cascaded H-bridge.The basic operational principle is stated to establish the stable mathematical model.The detailed analysis of power factor is shown and the calculation of circuit parameters and the range of load ratio are given.This paper brings up the control strategy of double closed-loop with balanced voltage loop.The feasibility and correction have been verified by experiment,and the anticipated aims of realizing rectify under unit power factor and maintaining the voltage balance among each module has been realized.