Optimized Power Conversion System for Mobile Air Radiation Monitoring System

This paper presents a high efficiency power conversion system for a mobile air radiation monitoring system (RMS). The proposed system consists of a two-stage dc-ac converter and a step-down converter. The two-stage dc-ac converter is used for the pump speed control of the mobile air RMS. For the dc-dc stage, by employing a soft-switching technique to all semiconductor devices, high efficiency and high power density are achieved. Meanwhile, the inverter stage controls the flow rate with the information provided by the air radiation monitor with variable voltage variable frequency (VVVF) algorithm; this enables active system control and energy saving. Considering that a battery, which is a finite energy source, is used in the system, the high efficiency characteristic gives the feasibility of the proposed power conversion system. The step-down converter is used to supply power to the electronics in the mobile air RMS. Finally, for the proposed power conversion system, a prototype is implemented, and its performance and validity are evaluated based on experimental results.