Controller for hybrid electric vehicle and method for controlling hybrid electric vehicle

A hybrid electric vehicle controller for a hybrid electric vehicle that includes an engine having a crankshaft, a motor generator, and a clutch arranged between the crankshaft and the motor generator, the controller comprising:

• processing circuitry configured to execute a restarting process that restarts the engine in a situation in which combustion is suspended in the engine when restarting of the engine is requested, wherein:
• the restarting process includes a first restarting process executed in a situation in which an engine speed is decreasing as a result of suspension of combustion in the engine, and the engine speed is less than a determination speed when restarting of the engine is requested;
• the first restarting process cranks the engine, by driving the motor generator in a state in which the motor generator is connected to the crankshaft through engagement of the clutch, and initiates fuel injection and ignition in the engine when a combustion initiation condition becomes satisfied during the cranking;
• the restarting process further includes a second restarting process executed in a situation in which the engine speed is decreasing as a result of suspension of combustion in the engine, and the engine speed is greater than or equal to the determination speed when restarting of the engine is requested;
• and
• the second restarting process initiates fuel injection and ignition in the engine and connects the motor generator to the crankshaft through engagement of the clutch after the engine is restarted, wherein
• the engine includes cylinders and pistons that are respectively reciprocated in the cylinders in synchronization with rotation of the crankshaft, and
• the combustion initiation condition is a number of cylinders in which the piston is moved beyond a compression top dead center reaching a predetermined number after starting the cranking by driving the motor generator.