Abstract

This paper proposes a novel three-phase inverter based on buck converter and an efficient control method for the operation. The inverter circuit is comprised of moderate numbers of elements in terms of reducing design density and cost and improving operation capabilities. Unlike the similar studies in the literature, an efficient inverter control method that is feedforward supported closed-loop control is applied to the inverter to augment the response performance of the inverter output on different operation conditions. The inverter topology has a modular structure for each output phase that provides independent control of output voltage and frequency. Thus, the inverter can provide close to sine wave output voltage to supply balanced or unbalanced wye-connected three-phase loads or independent single-phase loads. Both simulation and experimental test studies are done for the proposed inverter. The inverter is designed for 1.5 kW, 0–100 V_p and 0–50 Hz operating rates. The test results prove both the theoretical and real-time accuracy of the proposed inverter for producing close to sine wave output voltages with less than 5% total harmonic distortion (THD) values on different working points.

摘要

提出了一种基于降压变换器的新型三相逆变器及一种有效的运行控制方法。就降低设计密度和成本以及提高操作能力而言，逆变器电路由适量的元件组成。与文献中的类似研究不同，将有效的逆变器控制方法（前馈支持的闭环控制）应用于逆变器，以增强逆变器输出在不同工作条件下的响应性能。逆变器拓扑针对每个输出相位具有模块化结构，可提供对输出电压和频率的独立控制。因此，逆变器可以提供接近正弦波的输出电压，以提供平衡或不平衡的星形连接的三相负载或独立的单相负载。对拟议的逆变器进行了仿真和实验测试研究。逆变器设计用于1.5 kW，0–100 V_p和0–50 Hz的工作频率。测试结果证明了所提出的逆变器在产生接近正弦波输出电压且在不同工作点上的总谐波失真（THD）值小于5％时，在理论上和实时上均具有准确性。