Method for operating a spark-ignition internal combustion engine and controller for carrying out the method

A method for operating a spark-ignition internal combustion engine,

• wherein said internal combustion engine is operated using hydrogen as fuel,
• wherein said internal combustion engine comprises an exhaust gas recirculation device which recirculates exhaust gas into a combustion chamber, at least in some ranges, and/or an inert medium supply device which is configured to supply an inert medium that does not participate in the combustion into said combustion chamber, and
• wherein a lambda injection value is a value that indicates the formation of a mixture on the basis of an injection fuel quantity (Finjection) to be supplied to the combustion chamber of said internal combustion engine and an air quantity (L) to be supplied to said combustion chamber from outside of said internal combustion engine,
• the method comprising:
• determining the injection fuel quantity, at least in some performance ranges, independently of a lambda target value at least on the basis of a default fuel quantity (Fdef) and on the basis of an exhaust gas recirculation quantity (R) and/or an inert medium supply quantity,
• determining the injection fuel quantity, at least in the some performance ranges, on the basis of the air quantity, wherein the injection fuel quantity is determined at least on the basis of a lambda target range ([λtarget-l;
• λtarget-u]) of lambda target values, that is limited at least on one side by a first lambda target limit value, and in the lambda target range ([λtarget-l;
• λtarget-u]) independently of a lambda target value such that the lambda injection value is within the lambda target range, wherein a lambda default value (λdefault) is determined on the basis of the default fuel quantity (Fdef) and the air quantity (L) and it is determined if the lambda default value (λdefault) is within the lambda target range ([λtarget-l;
• λtarget-u]), wherein, if the lambda default value (λdefault) is outside of the lambda target range, the injection fuel quantity is corrected with respect to the default fuel quantity (Fdef) such that the lambda injection value is within the lambda target range,
• injecting the determined injection fuel quantity into the combustion chamber,
• wherein the lambda target range ([λtarget-l;
• λtarget-u]) is dependent upon the exhaust gas recirculation quantity (R) and/or inert medium supply quantity.