A METHOD FOR CONTROLLING THE OPERATION OF A HYDROGEN COMBUSTION ENGINE SYSTEM OF A VEHICLE

A method for controls the operation of a hydrogen combustion engine system of a vehicle including a hydrogen combustion engine and an exhaust aftertreatment system, EATS, to reduce emissions in the engine exhausts. The EATS comprises a selective catalyst reduction, SCR, catalyst and an ammonia slip catalyst, ASC, arranged downstream of the SCR catalyst. The method includes: identifying a regeneration time window for performing regeneration of the ASC; in response of identifying the regeneration time window, operating the hydrogen combustion engine in an H2 exhaust excess mode defined by an amount of unburnt H2 of at least 1.5 mol % in the engine exhaust and regenerating the ASC by using the unburnt H2 in the engine exhausts and reaching a regeneration temperature of at least 500° C.