开关电感准Z源逆变器及其改进型号在升压比方面不能满足新能源领域的严苛需求,限制了Z源逆变器在光伏逆变及其微电网中的运用。通过对传统开关电感准Z源逆变器拓扑结构的改变,提出了一种具有高电压增益的增强型开关电感准Z源逆变器,在原来的一组开关电感的基础上仅再增加一组开关电感,既避免了硬件结构过于复杂,也避免了直通占空比的取值范围过小,同时使得升压比提高5~40倍;确保了输入电流连续;并且X型LC网络的电容电压应力和电感电流脉动得到了有效降低。本文首先对增强型拓扑结构进行了详细的理论分析,然后进行了仿真实验,最后利用实物装置验证了增强型拓扑的可行性和优越性。
Switched-inductor quasi-Z-source inverter and its improved version in terms of boost ratio can- not meet the stringent demands of new energy field, limiting the utilization of Z-source inverter in photovoltaic inverter and micro-grid. This paper proposes an enhanced switched-inductor quasi-Z-source inverter topology with a high voltage gain by changing the traditional switched-inductor quasi-Z-source inverter. On the basis of one switched-inductor cell, a new switched-inductor cell is added in the new topology, which avoids that the hardware structure is too complex and shoot-through duty ratio range is too narrow, and allows the boost ratio to increase 5 -40 times; the continuous input current can be ensured. Moreover, both the capacitor voltage stress and inductor current ripple are effectively reduced in LC network X-shape structure. In this paper, the enhanced topology is theoretically analyzed in detail. On this basis, some simulations and experiments are carried out to validate the feasibility and superiority of the proposed topology.