For a stand-alone solar pump, Z-source inverter (ZSI) is being preferred because of its single-stage power conversion capability with buck-boost ability. As compared to traditional ZSI, series Z-source inverter (SZSI) reduces the voltage stress on capacitor and inrush current of the inductor significantly. In this paper, modes of operation of the SZSI for an induction motor load are explained. When an induction motor runs at a low power factor, an additional mode exists. In this mode, high-magnitude pulses appear on the DC link voltage if the decoupling capacitor is not used with an unidirectional source like solar photovoltaic (PV). In addition, an improved modulation technique is proposed to improve the performance of SZSI. This paper presents a performance of SZSI with solar photovoltaic as a source and an induction motor coupled with the centrifugal pump as a load. Simulation results show the performance of the proposed scheme. Experimental and simulation results demonstrate the validity of analysis. Therefore, SZSI is a promising topology for the solar PV stand-alone system.

中文翻译：

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应用太阳能光伏给水泵的串联 Z 源逆变器的性能改进

对于独立的太阳能泵，Z 源逆变器 (ZSI) 是首选，因为它具有单级功率转换能力和升降压能力。与传统的ZSI相比，串联Z源逆变器（SZSI）显着降低了电容上的电压应力和电感的浪涌电流。在本文中，解释了感应电机负载的 SZSI 操作模式。当感应电机以低功率因数运行时，存在附加模式。在此模式下，如果去耦电容器未与太阳能光伏 (PV) 等单向电源一起使用，则直流链路电压上会出现高幅度脉冲。此外，还提出了一种改进的调制技术来提高 SZSI 的性能。本文介绍了以太阳能光伏为源，以感应电机与离心泵耦合为负载的 SZSI 的性能。仿真结果表明了所提出方案的性能。实验和仿真结果证明了分析的有效性。因此，SZSI 是一种很有前途的太阳能光伏独立系统拓扑结构。