A control method and system to control a pair of electric motors driving a vehicle. The steps provided for are: determining, in a control cycle N and by means of a first processing core, for a first electric motor, a first electric current target based on a first torque or speed target; determining, in the control cycle N and by means of a second processing core, for a second electric motor, a second electric current target based on a second torque or speed target; controlling, in the control cycle N and by means of the first processing core, a first electronic power converter connected to the first electric motor so as to pursue the first electric current target; and controlling, in the control cycle N and by means of the second processing core, a second electronic power converter connected to the second electric motor so as to pursue the second electric current target.

A control method and system to control a pair of electric motors driving a vehicle. The steps provided for are: determining, in a control cycle N and by means of a first processing core, for a first electric motor, a first electric current target based on a first torque or speed target; determining, in the control cycle N and by means of a second processing core, for a second electric motor, a second electric current target based on a second torque or speed target; controlling, in the control cycle N and by means of the first processing core, a first electronic power converter connected to the first electric motor so as to pursue the first electric current target; and controlling, in the control cycle N and by means of the second processing core, a second electronic power converter connected to the second electric motor so as to pursue the second electric current target.

An abnormality diagnosis system configured to diagnose an abnormality of an electric drive system mounted on a mobile body to drive a motor for moving the mobile body, includes: an information acquisition unit configured to acquire a motor output information which is information related to an output state of the motor; an output state determination unit configured to determine whether the output state of the motor is in a low output state that does not contribute to a movement of the mobile body by using the motor output information; and a diagnosis execution unit configured to diagnose an abnormality of the electric drive system when it is determined that the motor is in the low output state.

An abnormality diagnosis system configured to diagnose an abnormality of an electric drive system mounted on a mobile body to drive a motor for moving the mobile body, includes: an information acquisition unit configured to acquire a motor output information which is information related to an output state of the motor; an output state determination unit configured to determine whether the output state of the motor is in a low output state that does not contribute to a movement of the mobile body by using the motor output information; and a diagnosis execution unit configured to diagnose an abnormality of the electric drive system when it is determined that the motor is in the low output state.

A process for controlling an electric motor includes providing a functional relationship, which associates a first and a second quantity , indicative of a torque delivered by the electric motor and of the supply voltage respectively, with a speed parameter of the electric motor, determining a pair of values of the first and of the second quantity , determining a value of a third quantity indicative of an output speed of the electric motor, determining a value of the speed parameter corresponding to the pair of values determined through the functional relationship, determining a value of a fourth quantity indicative of a difference between the value of the speed parameter and the value of the third quantity, determining a target value for the first quantity as a function of the value of the fourth quantity, and controlling the electric motor according to the determined target value.

A process for controlling an electric motor includes providing a functional relationship, which associates a first and a second quantity , indicative of a torque delivered by the electric motor and of the supply voltage respectively, with a speed parameter of the electric motor, determining a pair of values of the first and of the second quantity , determining a value of a third quantity indicative of an output speed of the electric motor, determining a value of the speed parameter corresponding to the pair of values determined through the functional relationship, determining a value of a fourth quantity indicative of a difference between the value of the speed parameter and the value of the third quantity, determining a target value for the first quantity as a function of the value of the fourth quantity, and controlling the electric motor according to the determined target value.

A device for driving a plurality of motors, including an inverter connected to a DC terminal; a multi-phase motor connected to the inverter; and a single-phase motor serially connected to the multi-phase motor, wherein a number of frequency of current input to the multi-phase motor when driving the single-phase motor and the multi-phase motor at the same speed is smaller than the number of frequency of current input to the multi-phase motor when driving the single-phase motor and the multi-phase motor at different speeds. Accordingly, a plurality of motors can be simultaneously driven at different speeds, by using a single inverter.

A device for driving a plurality of motors, including an inverter connected to a DC terminal; a multi-phase motor connected to the inverter; and a single-phase motor serially connected to the multi-phase motor, wherein a number of frequency of current input to the multi-phase motor when driving the single-phase motor and the multi-phase motor at the same speed is smaller than the number of frequency of current input to the multi-phase motor when driving the single-phase motor and the multi-phase motor at different speeds. Accordingly, a plurality of motors can be simultaneously driven at different speeds, by using a single inverter.

A system (11) for balancing at least one parameter to be balanced of an electric motor of a propulsion system (1), in particular of an aircraft, includes at least two electric motors (3, 4) and a propulsion member (2) driven in rotation by said electric motors. The balancing system is configured to calculate a correction of the speed setpoint (Corr_Cons_VI, Corr_Cons_V2) as a function of a correction factor (F1, F2) of the speed setpoint depending on a parameter (P1, P2) of the associated electric motor that is intended to be balanced and on a speed setpoint (Cons_VH) of the propulsion member (2).

A system (11) for balancing at least one parameter to be balanced of an electric motor of a propulsion system (1), in particular of an aircraft, includes at least two electric motors (3, 4) and a propulsion member (2) driven in rotation by said electric motors. The balancing system is configured to calculate a correction of the speed setpoint (Corr_Cons_VI, Corr_Cons_V2) as a function of a correction factor (F1, F2) of the speed setpoint depending on a parameter (P1, P2) of the associated electric motor that is intended to be balanced and on a speed setpoint (Cons_VH) of the propulsion member (2).