Plasma ignition device and plasma ignition method

摘要

A plasma ignition device 20 includes a spark plug 100, a DC power supply 210, an AC power supply 220, and a coupling section 300. The coupling section 300 includes a capacitor 320 which electrically connects the AC power supply 220 to the spark plug 100. The coupling section 300 reduces the capacitance of the capacitor 320 in the second ignition mode in which transmission of AC power is halted, as compared with that in the first ignition mode in which AC power is transmitted to the spark plug 100.

主权项

1. A plasma ignition device comprising:
a spark plug; a DC power supply for generating DC power used to generate spark discharge between electrodes of the spark plug; an AC power supply for generating AC power used to generate AC plasma between the electrodes between which the spark discharge has been generated; and a coupling section which couples the DC power and the AC power together and transmits resultant coupled power to the spark plug and which includes a capacitor for electrically connecting the AC power supply to the DC power supply and to the spark plug; the plasma ignition device further comprising: a power supply control section for controlling the DC power supply and the AC power supply while making a changeover between a first ignition mode in which the AC power is transmitted to the spark plug, and a second ignition mode in which transmission of the AC power to the spark plug is halted, and a capacitance control section for reducing, in the second ignition mode, capacitance of the capacitor as compared with that in the first ignition mode.