무가선 트램용 추진 전동기 설계 및 특성 비교

Comparison of Traction Motor design and characteristics for battery driven hybrid tram

The latest generation of tram is low-floor design, various nations in europe and japan have developed battery driven hybrid trams that combine battery and wiring. Battery driven tram system is achieved by contactless power supply system, thus system is needed high efficiency, high power and low weight traction motor for maximization of energy efficiency. Research from abroad is still in induction motor(IM) application, and it is not meet the efficiency and the power per unit volume in IPMSM. In this paper, we design compare IM and IPMSM to apply battery driven tram, and then compare these motors. To design the motor, we estimate the loading condition at first. Loading condition includes rolling resistance, air-drag resistance, and slope resistance. Based on the loading condition by estimation, we determine the power and compute rated voltage and rated current. In this paper, voltage is limited by battery voltage level. As a result, volume about IM is 1.98 times bigger than IPMSM under same condition. Even though IPMSM is bigger than IM in power density per volume, we consider more factors for actual application because there are demagnetization of permanent magnet in IPMSM and so on by external environment conditions.