An Integrated Power Supply Design for Motor Encoder Utilizing Common-Mode Voltage with Phase Shifted SPWM

Motor encoder is a rotational speed and position measuring device in high performance servo motor. It needs an additional 5V or 12V power cable connected with the inverter for power supply. In order to seek simplicity in engineering, this paper proposes a common mode voltage-fed method to supply power for the motor encoder, eliminating the need for the additional DC power cable. Furthermore, compared with the conventional SPWM technology, the Phase Shifted-SPWM (PS-SPWM) technology is adopted to improve the common-mode voltage and finally reduces the output DC voltage ripples. Experimental results validate the feasibility and effectiveness of the proposed design.