Motor drive technology - history and visions for the future

Since the invention of the motor which converts electrical energy into mechanical energy, it has been used in all kinds of applications the range of which continues to expand. Furthermore, in order to match the speed of motors to the optimum operating point of a driven machine or application, the efforts to develop variable speed drive technology have also advanced. Variable speed motor drives require power electronics and it can be said that this work has contributed to the prosperity of today´s world wide economy and allows people to enjoy a more complete social life. On the other hand, the level of the electric power used for driving motors accounts for the largest proportion of industrial electric power, and thus it is impossible to disregard its influence on the global environment. This paper takes the viewpoint of adjustable speed of motors. It reviews Yaskawa´s progress in technology and product development and also introduces the measures of our company for the future. In addition, reference is also made to the future of motor drive technology.