Near-to-Zero Switching Synchronization Approach for DC Electromagnet Actuated Relays

This article puts forward an idea for dc electromagnetically (EM) actuated switching devices operation improvement by means of an electronic controller application. The idea is aimed at applying compensation for the movable armature inertia and the time required for coil (de)energization. Based on the results of the measurements of the tested contactors switching parameters, the most efficient (de)energizing conditions for “near–to–zero” synchronized switching (NZSS) method application were determined. The NZSS process realization approach operates on the principle of controlling the driving coil supply voltage delivery moment. By means of the same controller circuit, voltage-zero synchronized contacts making and current-zero synchronized contacts breaking operations were realized. The method was experimentally verified for various supply conditions and load parameters. Long-term tests confirm the suitability of the method for low-voltage (LV) EM actuated switching devices. The circuit was able to control various EM drives with no modification required for the structure in which it was used.