PWM Parallel Resonant Inverter Designed for Marine Diesel Emission Control system

From a viewpoint of environmental protection, it is important to reduce PM (particulate matters) causing an air pollution. In order to reduce PM, it is necessary to heat at high temperature the exhaust gas from marine diesel engine. We have proposed the after-treatment system utilizing an induction heating for reducing PM in exhaust gas as a diesel emission control system. In the case of an induction heating, although a metallic filter is efficiently heated by using a ferromagnetic material, metallic characteristics change from ferromagnetism to paramagnetism and the circuit parameters are also changed rapidly, if a temperature of metallic filter reaches Curie temperature. Therefore PWM parallel resonant inverter is proposed as power supply for heating corresponding to changing circuit parameters. In this paper, easy control method of the proposed inverter and heating method of filter are explained, and the circuit characteristics are analyzed by numerical analysis