Congratulations to Gowtham!
Gowtham Venkatraman passed the Ph.D. candidacy examination in the Department of Mechanical and Aerospace Engineering. His dissertation research is titled “Process modeling of ultrasonic additive manufacturing.” Gowtham’s committee members are Profs. Dapino (Advisor), Cho, Gilat, and Ramirez.
This study addresses the design of a new type of permanent magnet contactor, which uses forced breaking to overcome failure conditions. A multi-objective optimisation method based on the genetic algorithm is used to design the contactor considering the effects of average closing time, average breaking time, impact energy, Joule heat and contactor volume. Four prototypes have been fabricated according to the optimised parameters. A control circuit is developed to increase breaking reliability. The circuit is designed as two separate modules: a normal working module and a protection module. The former is used during the normal contactor operation and the latter is used for forced breaking protection. Breaking failures are detected by comparing the time delay between the breaking control voltage and the auxiliary contact voltage. A durability experiment has been conducted to verify the protection function of the proposed PM contactor. Experimental results show that the normal working module fails to break the contactor in the last testing cycle. However, under the actuation of the protection mechanism, the contactor is forced to break and the power circuit can be successfully switched off.
L. SHU, S. Zhao, Z. Wu, W. Chen, and M.J. Dapino, “Optimal design and control of a new permanent magnet AC contactor with forced breaking mechanism,” IET Electric Power Applications. Vol. 14, Issue 2, pp. 157-164, 2020. doi:10.1049/iet-epa.2019.0193