ELECTRIC MOTOR DRIVE SYSTEM

A motor drive system includes a first interlock mechanism (160) configured to be activated in response to transition to an operable state of an interruption device (SP), to open an open/close device (190), a second interlock mechanism (210) configured to be activated in response to transition to an openable state of a case containing a power control unit (200), to open the open/close device (190), and a control device (350). The control device (350) is configured to perform, when the first interlock mechanism (160) is activated, a first process of opening the open/close device (190) after shutting down the power control unit (200), and to perform, when the second interlock mechanism (210) is activated, a second process of opening the open/close device (190) while driving the power control unit (200), instead of the first process, depending on a counter electromotive voltage generated by a motor (MG1).