Hybrid electric vehicle and shift control method thereof

A method of controlling shifting of a hybrid electric vehicle comprising an engine, a first motor, an engine clutch, a second motor, and a transmission, the method comprising:

• calculating a target torque reduction amount for the transmission to shift;
• determining whether the engine clutch is in a locked-up state;
• based on the engine clutch being determined to be in the locked-up state, setting an intervention control sequence by designating the first motor and the second motor as a higher priority control motor and a lower priority control motor;
• setting a torque reduction amount of the higher priority control motor based on a result of comparing the target torque reduction amount with an intervention limit of the higher priority control motor;
• and
• based on the target torque reduction amount exceeding the intervention limit of the higher priority control motor, setting a torque reduction amount of the lower priority control motor,
• wherein the first motor is connected to the engine, and the second motor is connected to an input shaft of the transmission.

A non-transitory computer-readable recording medium having stored thereon a program for executing a shift control method of a hybrid electric vehicle comprising:

• calculating a target torque reduction amount for a transmission to shift;
• determining whether an engine clutch is in a locked-up state;
• based on the engine clutch being determined to be in the locked-up state, setting an intervention control sequence by designating a first motor and a second motor as a higher priority control motor and a lower priority control motor;
• setting a torque reduction amount of the higher priority control motor based on a result of comparing the target torque reduction amount with an intervention limit of the higher priority control motor;
• and
• based on the target torque reduction amount exceeding the intervention limit of the higher priority control motor, setting a torque reduction amount of the lower priority control motor,
• wherein the first motor is connected to the engine, and the second motor is connected to an input shaft of the transmission.