Experimental investigation of shaft transducerless speed and position control of ac induction and interior permanent magnet motors

Abstract

In order to drive AC motors with high efficiency and high motion performance, and to provide accurate speed/position control, motor shaft speed and/or position feedback is required. For this purpose, usually transducers (encoder, tachogenerator, resolver, etc.) are installed on the shaft. However, transducers are not preferred in most of the applications since they increase the cost and decrease the reliability of the drive due to their failure prone structure and connections. In such applications, the speed and/or position information of the motor is obtained by estimation methods without using shaft transducers. In this work, motor types and speed/position estimation methods will be surveyed, appropriate estimation methods will be determined based on the motor type (induction or interior permanent magnet synchronous) and the application requirement (speed and/or position control requirement). High frequency signal injection, speed adaptive flux observer, open loop integration based flux observer methods, and combination of them in a hybrid algorithm will be investigated. By implementing these methods, the experimental performance of the shaft transducerless speed and/or position controlled vector control based induction and interior permanent magnet synchronous motors will be presented. The study helps the motion control engineers select the suitable motor and implement the appropriate speed/position estimation algorithm for a given application.