Microcontroller-Based Synchronized Switching Drive for DC Electromagnet-Driven Apparatus

In this paper, we advance the concept of an electronic controller for switching devices actuated by means of direct current (DC) electromagnets. Based on the method of controlling the supply voltage delivery and disconnection moment to the drive coil, it is feasible to control switching-on and switching-off operations of an electromagnetic (EM) circuit-breaker (CB). The developed control method, built upon an ATmega328P microcontroller and operating in the Arduino IDE 2.3.4 environment, minimizes the impact of CB moving part inertia and drive coil (de)energization time. As a result, it enables contacts to be made at the near-to-zero point of the voltage waveform and contacts to break at the near-to-zero point of the current waveform. Consequently, the implementation of the proposed synchronized switching (SS) method allows the minimization of overvoltages and overcurrents during switching operations. Through continuous monitoring of the drive coil supply source parameters, the developed electronic controller allows for minimizing the impact of potential voltage fluctuations on CB switching parameters. Extensive laboratory tests confirmed the effectiveness of the proposed controller and applied method for controlling various types and sizes of EM contactors and relays.