四相开关磁阻电机新型T型功率变换器研究

Research on New T-Type Power Converter for Four-Phase Switched Reluctance Motor Drives

为了扩大四相开关磁阻电机(SRM)驱动系统的输出功率范围,提出了一种新型不对称T型功率变换器。该功率变换器由改进的T型功率变换器和辅助电路构成:T型变换器为多电平电路,可使得电机绕组在多种模式下工作,控制灵活;辅助电路能够使直流侧分压电容在实现直流侧电压钳位的同时用作电机相电流上升及下降期间的电压抬升。对电机不同运行模式进行了详细分析,并对比了所提T型功率变换器与二极管中性点钳位(NPC)功率变换器的效率及成本。对SRM系统进行了仿真研究,结果表明所提新型T型功率变换器可提升SRM系统的转速及功率输出能力,提高系统整体效率,适用于电机高速运行场合。

Aiming at extending the output speed range of four-phase switched reluctance motors,a new asymmetric T-type power converter is proposed.The power converter is composed of modified T-type three-level converters and auxiliary circuits.T-type converter is a multi-level converter which can provide more flexible phase control.The DC-link capacitors in the auxiliary circuits are used for voltage level clamping as well as DC voltage-boosting capacitors to produce additional voltage during the rise and fall period of a motor phase current.The operation and analysis are detailed for different operation modes.Comparisons are made between the proposed converter and diode neutral-point clamped(NPC)multilevel converters on efficiency and cost.The simulation results show that the proposed new T-type power converter increases both speed and output power,improves the efficiency of SRM system,and is suitable for high speed applications.