Ignition device and method for igniting an air/fuel mixture

A method for igniting an air/fuel mixture in m combustion chambers with m∈ (natural numbers without zero) and m≥2, of an internal combustion engine, wherein, within a predetermined time interval, an ignitable mixture is generated in at least one combustion chamber, wherein, by means of an electrical high-voltage pulse, an electrically conductive channel between at least two electrodes of the respective combustion chamber is generated in the at least one combustion chamber with ignitable mixture, wherein an electrical high-frequency alternating voltage for generating and maintaining a plasma in the at least one combustion chamber with ignitable mixture is fed to the at least two electrodes with the conductive channel,

• wherein the electrical high-frequency alternating voltage is fed to the at least two electrodes in the at least one combustion chamber with ignitable mixture before generation of the electrically conductive channel between the at least two electrodes of the respective combustion chamber,
• wherein, after a predetermined time interval following the generation of the plasma, the electrical high-frequency alternating voltage is, for at least a predetermined dead time, shut off from at least those at least two electrodes of a respective combustion chamber via which the plasma was generated, wherein the predetermined dead time amounts to 0.5 ms to 2 ms.

A method for operating an ignition device for igniting an air/fuel mixture in at least one combustion chamber, of an internal combustion engine, having at least one ignition system for each combustion chamber, at least one high-voltage source for generating an electrical high-voltage pulse at an output of the high-voltage source and having at least one high-frequency voltage source for generating an electrical high-frequency alternating voltage at an output of the high-frequency voltage source, wherein m ignition systems are provided, with m∈ (natural numbers without zero) and m≥2,

• wherein the electrical high-frequency alternating voltage at the output of a high-frequency voltage source is fed to n ignition systems, wherein n∈ and 2≤n≤m,
• wherein the output of at least one high-frequency voltage source is electrically connected at separate times, in succession and temporarily, with in each case p ignition systems of the n ignition systems, wherein 2≤p≤n−1, m≥3 and n≥3.

A method for igniting an air/fuel mixture in m combustion chambers with m∈ (natural numbers without zero) and m≥2, of an internal combustion engine, wherein, within a predetermined time interval, an ignitable mixture is generated in at least one combustion chamber, wherein, by means of an electrical high-voltage pulse, an electrically conductive channel between at least two electrodes of the respective combustion chamber is generated in the at least one combustion chamber with ignitable mixture, wherein an electrical high-frequency alternating voltage for generating and maintaining a plasma in the at least one combustion chamber with ignitable mixture is fed to the at least two electrodes with the conductive channel,

• wherein the electrical high-frequency alternating voltage is also fed to the at least two electrodes of at least one such combustion chamber in which no ignitable mixture is present.