Minimizing the power consumption of a clapper type dc electromagnet in intermittent operation
A technique for designing a clapper type dc electromagnet with its power consumption being minimized is proposed. The technique is based on the experimentally obtained load characteristics and mathematical models of thermal characteristics of the winding that depend on the maximum temperature in its bulk. The optimality criterion for power consumption is determined, and an algorithm for searching for its best solution by two phase scanning of the factor space is developed. The main dimensions of an optimized electromagnet are calculated as an example for different values of the initial parameters: the working gap, the counteracting force, the ratio of the maximum power supply voltage to the actuation voltage, and the power overload factor. Simple mathematical expressions for the determination of the main dimensions of an electromagnet are provided in order to reduce the time expenditure at the design stage. These expressions were obtained by generalizing the results of computational experiments using the methods of active experiment planning and the similarity theory. An algorithm for calculating these dimensions is outlined. The proposed technique was used successfully in the process of designing a new series of dc contactors for severe operating conditions.