A Design Based on Operator Theory and Isomorphism: Operator-Based Nonlinear Adaptive Control for a Calorimetric Power Loss Measurement System Using a Peltier Element

Recently, power conversion devices have been increasingly becoming more efficient at facilitating the electrification of vehicles and saving energy. To evaluate and design power conversion equipment, it is necessary to measure the power loss of the equipment with a high degree of accuracy. Power loss is generally determined from the difference between the input power and output power using a wattmeter. However, as a power conversion device becomes more efficient, the ratio of the power loss to the measured input and output power is smaller, and the error in the measuring device becomes nonnegligible. A solution to this problem is to determine the power loss using the quantity of heat radiated from the power conversion equipment. This method is called a
calorimetric method
. In the previous study, the calorimeter using a Peltier element was proposed. In this article, a nonlinear temperature control system that adapts to changes in the heat capacity of the measured object is designed based on operator theory and adaptive control theory. Since the adaptive control theory requires the control system to satisfy passivity, a feedback control system that guarantees passivity is designed based on isomorphism. Furthermore, experiments are performed to confirm the effectiveness of the proposed control system.