Self-Initial Position Alignment of Incremental Encoder for Switched Reluctance Motor

Incremental Encoders (IEs) are widely used in the speed and position control of electric motors due to their compact sizes and low costs compared to other alternatives. An initialization process is necessary when an IE is used for position measurement. This paper introduces a reliable and cost-effective initialization method for the IE that is mounted on the shaft of a Switched Reluctance Motor (SRM). The method is based on a sequence that first energizes a phase winding of the SRM through a relay for a short time to have an alignment between the stator and the rotor pole and then resets IE output for starting position measurement. This method surpasses other initialization methods because it does not require any observation process and is independent of motor parameters. Experimental results validate the robustness and reliability of the proposed approach.