Patent ID: 6883306

Claim:
An emission treatment system for a vehicle, comprising: a plasma reactor configured to reduce noxious emissions of an engine being disposed near one end of an exhaust pipe; a power supply unit for supplying power to said plasma reactor, wherein said power supply unit comprises: a power source unit for providing sower supplied to said plasma reactor; and a transformer configured to boost a voltage of power supplied from said power source unit and to supply said boosted power to said plasma reactor; a direct-connecting pipe configured to connect said plasma reactor to said exhaust pipe such that exhaust emissions can pass through said plasma reactor; a bypass pipe connected to said direct-connecting pipe both before and after said plasma reactor such that said exhaust emissions can bypass said plasma reactor; a control valve disposed at a position where said direct-connecting pipe and said bypass pipe intersect being configured to selectively open and close said direct-connecting pipe and said bypass pipe; and a control unit coupled to said power supply unit and said control valve, said control unit controlling a voltage of power supplied to said plasma reactor and an operation of said control valve, wherein said control unit is programmed to perform a control method comprising: detecting a primary voltage of said transformer; determining whether said detected primary voltage of said transformer is less than a predetermined voltage; stopping power supply to said plasma reactor if it is determined that said primary voltage is not less than said predetermined voltage; detecting a primary current from said transformer; determining whether said primary current of said transformer is less than a predetermined current; and controlling said control valve such that said exhaust pipe is closed and said bypass pipe is opened and controlling said power supply unit such that a predetermined level of power is supplied to said plasma reactor.