半导体装置现在发展到在列车上采用变压和变频的三相电源是相当可行的。没有电刷的三相感应电机的许多优点早就被牵引工程师所承认,例如,在一些国家内已进行试验,证明推动了内燃机车和电力机车的发展。然而直到现在已经订购的只是先驱车队的机车,功率调节装置成本仍影响广泛采用三相驱动。 It is quite feasible that the semiconductor device is now being developed to use three-phase power in transformers and frequency converters in the train. Many of the advantages of brushless three-phase induction motors have long been recognized by towing engineers. For example, tests have been carried out in several countries that have proved to be driving the development of diesel and electric locomotives. Until now, however, only the pioneering fleet of locomotives has been ordered, and the cost of power regulation still affects the widespread adoption of three-phase drives.