Development of sensorless-vector-controlled electric vehicle with No variable transmission

摘要

One of the most important technologies for electric vehicles (EV's) will be control technology for driving AC motors. It is desired for control technology of the AC motors to have the following characteristics. 1) It does not require a position/speed sensor for controlling motor drive, which is mounted on rotor shaft. 2) It is a kind of vector controls that can produce torque quickly, efficiently and/or precisely. 3) It has wide driving-range and allows to realize EV's with no variable transmission. 4) It has so good regeneration performance that it can bring EV's to a full stop by electric brake only. In order to attain all of the above characteristics simultaneously, so-called sensorless vector control schemes will be indispensable. The frequency-hybrid (FH) vector control scheme will be one of high potential candidates as such for EV's. This paper presents design, realization and field test results of a radical new sensorless-vector-controlled EV with no variable transmission based on the FH vector control scheme, and clarifies its usefulness.