Research of Current Resonant Inverter for SR Motor

目前，SR电机受到了严格的研究，并且存在各种各样的SR电机驱动电路。磁阻电动机结构简单、刚性好、成本比感应电动机低，是电动汽车中最有前途的应用领域之一。磁阻电动机具有较高的电抗，在每个供电周期后都需要回收存储的励磁能量。因此，能量回收周期通常会变长，为了获得更高的输出功率和更高的效率，需要更短的能量回收周期。它们中的许多都采用硬开关类型，并且它们可能引起高电磁干扰（EMI）并导致相当高的开关损耗。具有谐振电路的软开关型驱动电路似乎具有较小的EMI和较小的开关损耗。本研究所研究的驱动电路为软开关型，仅包含四个开关元件，具有开关损耗低、电磁干扰小、效率高等优点。实验结果表明，该电路可以提供一种低成本、高效率的低电磁干扰系统，以满足进一步降低电磁干扰的需求。

The SR motors are rigorously investigated in these days, and there are various kinds of SR motor drive circuits. Electric vehicle is one of the most promised field of reluctance motor applications because of their simple and rigid structure, and the future possibility of lower cost than that of induction motors' is also strongly focused point.This motor has relatively high reactance and the stored excited energy has to be retrieved after each powering period. Therefore the energy retrieval period usually becomes longer and the shorter retrieval period is desired to obtain higher output power and higher efficiency.For this purpose, some kinds of driving circuits are already proposed. Many of them are utilizing hard switching types, and they may cause high electro-magnetic interference (EMI) and lead to rather high switching losses. A soft-switched type drive-circuits with resonant circuit seems to have less EMI and less switching losses. However, they utilize continuous resonant-switchings, and may result in high resonant circuit losses.This research studied with soft-switched type drive-circuit, including only four switching devices, and has the merits of low switching losses, low EMI, and higher efficiency. The proposed circuit is expected to provide a low-cost, highly efficient low-EMI system to meet the demand for further reductions in EMI by the experimental results.