该文在开关电感型Z源逆变器的基础上提出一种高电压增益的开关电感型Z源逆变器。与传统的开关电感型Z源逆变器相比，新型拓扑不仅保留了X型的基本结构，而且将二极管和逆变桥的位置互换，同时增加了2个电感和6个二极管，这样可以减小电容电压应力，增大直流链路峰值电压，使输入电流具有连续性；另外，新型拓扑的控制方法简单，采用直接升压控制方法，它以正弦波为调制波、三角波为载波，是一种基于正弦脉宽调制控制技术的一种控制方法。在理论分析的基础上，对新型拓扑进行仿真试验，结果表明：当直通占空比为0.139、调制系数为0.85时，新型拓扑直流链路峰值电压为127.95 V，电容电压应力为39.50 V，而传统拓扑的直流链路峰值电压为89.65 V，电容电压应力为68.40 V，新型拓扑在获得较大直流链路峰值电压的同时，可以保证电容上承受的电压应力较小。通过仿真试验，验证了新型拓扑的优点。%On the basis of the switched-inductor Z-Source inverter, this paper proposes a new switched-inductor Z-source inverter topology with high boost voltage, which is totally different from any other existing Z-source inverters from the viewpoint of circuit structures and operating principles. This new topology not only retains the basic X-shape structure, but also can exchange the position between diode and inverter bridge by adding two inductors and six diodes. It excels at reducing the voltage stress and increasing the peak dc-link voltage, meanwhile ensuring the continuity of the input current; moreover, it can be controlled simply by adopting the boost control, which is also well known in the traditional switched-inductor Z-source inverter. That is to say, it uses the sine wave as the modulation wave, and the triangle wave as the carrier wave. The method is based on the sinusoidal pulse width modulation control technology. When the triangular carrier wave amplitude is greater than the sine wave's peak value or conversely less than the sine wave's negative peak value, the three-phase bridge arms of the inverter was straight at the same time. From the viewpoint of the switching states of the main circuit connected with the new switched-inductor Z-source impedance network, the operating principles of the proposed impedance network are similar to those of the traditional Z-source impedance network. Therefore, the substates of the new Z-source impedance network are classified as the shoot-through state and the non-shoot-through state, respectively. During the shoot-through state, all the switches of the inverter bridge are on, while the input diode is off. For the top switched-inductor cell and the bottom switched-inductor cell, all the inductors are connected in parallel, respectively. These inductors are charged by two capacitors. It appears that both the top and bottom SL cells perform the same function to absorb the energy stored in the capacitors. On the other hand, during the non-shoot-through state, the state corresponds to the six active states and the two zero states of the main circuit. Some switches of the inverter bridge are off, while the input diode is on. For the top switched-inductor cell and the bottom switched-inductor cell, all the inductors are connected in series, respectively. The stored energy is transferred to the main circuit. To verify the proposed concept and the theoretical analysis, it is given that the simulation of the novel switched-inductor Z-source inverter and the traditional switched-inductor Z-source inverter are under the condition of the simple boost control. When the shoot-through duty ratio is 0.139 and the modulation index is 0.85, the peak dc-link voltage will be up to 127.95 V using the novel topology, while the traditional topology yields a peak de-link voltage of 89.65 V. The capacitor voltage is 39.50 V using the novel topology, while using the traditional topology the capacitor voltage is 68.40 V. Therefore, the new topology has a higher boost factor than the traditional inverter.
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