This paper proposes advanced speed control for a five-leg voltage source inverter (FLVSI) that drives the dual three-phase induction motor system used in industrial manufacturing processes. The advanced speed control method consists of two controllers: 1) The first is a slip controller that satisfies the application requirement, i.e., to control the mechanical speed of two motors equally regardless of the load condition. 2) The second is an angle controller that satisfies the FLVSI requirement, i.e., to control the phase angle difference between the two motors for minimizing the common leg current because the common leg current can be twice higher than other leg's current depending on the operation condition of the dual motor. Stability analysis of the two controllers under advanced speed control is implemented, and the whole performance of the advanced speed control for the FLVSI-fed dual-motor drive system is shown to identify its feasibility through the experimental results.
Manuscript received October 26, 2017; revised December 28, 2017, January 31, 2018, and March 15, 2018; accepted April 6, 2018. Date of publication April 27, 2018; date of current version August 31, 2018. This work was supported in part by a grant from the R&D program of the Korea Railroad Research Institute, South Korea, and in part by the National Research Foundation of Korea grant funded by the Korea government (MSIT) (No. 2016R1A2B4010636). (Corresponding author: Kyo-Beum Lee.) Y.-S. Lim and K.-B. Lee are with the Department of Electrical and Computer Engineering, Ajou University, Suwon 16499, South Korea (e-mail: limys@ajou.ac.kr; kyl@ajou.ac.kr).
