Investigation of cost effective method to improve voltage sag ride through capability of AC coil contactors

This paper discusses the outcome of an investigation into the ride through capability and behaviour of electromagnetic contactors during voltage sag of different magnitude, duration initiated at various point on wave initiation and on the basis of extensive test results. Existing work done by various researchers in investigation of sensitivity of AC coil contractor to voltage sag and short interruptions and standards are reviewed. Few works have been reported on investigation of the behaviour of AC contactor to voltage sags, but no significant work has been reported in literature on cost effective methods to improve the voltage sag ride through capabilities of AC coil contactor. The test result of the behaviour of AC coil contactor for voltage sags of different magnitude, duration and point on wave initiation without the voltage sag ride through solution and with ride through improvement solution is presented. Effectiveness of solutions are verified experimentally.