中文摘要：

可再生能源发电系统由于受环境因素的影响,其输出电压范围较宽,需要逆变器能够适应宽范围的电压输入。双Boost逆变器能够实现单级升降压逆变,具有电路结构简单、功率器件少等优点。然而传统的调制策略中所有功率开关在整个工频周期中均处于高频开关状态,同时承受较大的电压电流应力,导通损耗和开关损耗大,系统效率低。提出一种半周期调制策略,使功率开关工作于半周期高频调制状态,减小了器件导通和开关损耗。对两种调制策略下电压电流应力进行对比分析,设计一台400 W原理样机,并通过仿真和实验验证半周期调制策略的优点。

英文摘要：

The renewable energy power generation system is easily affected by environment factors, and it is required that the inverter can adapt to its wide input voltage. Double Boost inverters can realize single stage conversion, which has the advantages such as its simple structure, less power devices and buck-boost ability. The traditional modulation strategies make all power switches in high frequency and make them sustain high voltage and current stress, which leads a heavy conduction loss and switching loss, with low efficiency. This paper proposes a half cycle modulation strategy, which makes power switches working in high frequency just in a half cycle, to reduce the device conduction and switching losses. Detail analysis and comparison of voltage and current stress between two strategies are given; also a 400 W prototype system is designed in the lab. The advantages of the half cycle modulation are verified by simulations and experiments.