US Patent 10011265 Hybrid vehicle and method for controlling the same

Inverterless running control is control in which an inverter is set to a gate cut-off state, an engine is driven to mechanically rotate a motor-generator and to generate in the motor-generator, counter-electromotive torque in accordance with a difference between a counter-electromotive voltage of the motor-generator and a system voltage, and a vehicle runs with drive torque applied to an output shaft as reaction force of the counter-electromotive torque. An ECU controls drive torque to produce driving force determined by an accelerator position by raising or lowering the system voltage during inverterless running control.