Mitigation Strategies to Improve the Performance of AC Contactor Against Voltage Dips

The performance of a process against voltage dips depends on the severity of voltage dips and the robustness of process equipment to voltage dips. This paper discusses about the performance of an AC contactor, one of the voltage sensitive equipment, against various types of voltage dips without and with mitigation techniques. First, lab tests are conducted to find the voltage-tolerance curves of the contactor without mitigation. Then, the tests are repeated with the AC-coil mitigated by Coil-Lock and phase-phase supply; and the tolerance curves of the device without and with mitigation are compared. To get better insight into the performance of the contactor, the severity of various types of voltage dips obtained from field measurements are compared with the voltage-tolerance curves of the contactor in both situations.