Active-control resonant ignition system

摘要

A method is disclosed for producing a corona discharge for igniting an air/fuel mixture in an internal combustion engine. An igniter is provided having a discharge tip that protrudes into a combustion zone. During a first stage of a combustion process, a first primary winding of a RF transformer is driven at a first predetermined voltage level and at a first resonant frequency that is based on a first impedance in the combustion zone prior to onset of combustion, for generating a corona discharge at the tip of the igniter. During a second stage subsequent to the first stage, a second primary winding of the RF transformer is driven at a second predetermined voltage level and at a second resonant frequency that is based on a second impedance in the combustion zone at a time that is subsequent to onset of the combustion process.

主权项

1. An ignition system for producing a corona discharge for igniting an air/fuel mixture in an internal combustion engine, comprising:
a radio frequency (RF) transformer comprising a secondary winding having a high voltage side and a low voltage side and comprising a plurality of primary windings; a plurality of power drive circuits, each power drive circuit coupled to a different primary winding of the plurality of primary windings; an ignition device coupled to the high voltage side of the secondary winding and having a high voltage electrode arrangement for receiving an amplified voltage from the secondary winding and for providing a discharge voltage at an electrode of the high voltage electrode arrangement to generate a corona discharge, the ignition device being part of an oscillating circuit having a resonant frequency that changes during different stages of a combustion cycle; a signal generator for providing different command signals to different power drive circuits of the plurality of power drive circuits at respective different stages of the combustion cycle, such that different primary windings are used to produce different voltage amplitudes at the resonant frequency of the respective stage of the combustion cycle; and a feedback subsystem for detecting an electric and/or electromagnetic field change of the ignition device by sensing a current in the secondary winding and for changing the different command signals provided to the different driver circuits of the plurality of driver circuits based on a determined correlation between the sensed current and an operating condition of the internal combustion engine.