A vehicle includes a five-phase electric machine with open windings driven at each side by phase legs of an inverter. A controller monitors for open-circuit windings. In response to detecting an open-circuit winding above a predetermined speed threshold, the controller operates the inverter to drive the windings that are not open-circuited in a square configuration.

An electric power steering device and method are disclosed. An electric power steering device according to an embodiment of the present invention comprises: a steering motor comprising a first winding and a second winding, each of Which receives applied three-phase power; a first control unit for controlling power supplied to the first winding; and a second control unit for controlling power supplied to the second winding, wherein, when one of a phase of the first winding and a phase of the second winding has failed to be opened, the control unit controlling the winding including the phase that has failed to be opened, among the first control unit and the second control unit, performs torque compensation control for additional output of compensation torque.

A drive controller according to an aspect controls drive of a three-phase motor, and includes an electric value calculation unit that calculates an electric value in each of coordinate axes of rotating coordinates of the three-phase motor based on an electric value that is at least one of a current value and a voltage value generated in the three-phase motor, and a fault determination unit that determines a fault phase having a fault in phases of the three-phase motor by combining positive-negative information on at least one of a difference between a calculation electric value calculated by the electric value calculation unit and a target electric value indicating a control target of an electric value in each of the coordinate axes, and a variation of the difference, with each of the coordinate axes.

A vehicle includes a five-phase electric machine with open windings driven at each side by phase legs of an inverter. A controller monitors for open-circuit windings. In response to detecting an open-circuit winding above a predetermined speed threshold, the controller operates the inverter to drive the windings that are not open-circuited in a square configuration.

An electric motor is electrically commutated with the aid of circuitry, in which the phase current experiences a zero crossing at certain time points per motor phase. Owing to the inductive load portion, the time of said zero crossing of a phase current occurs at different times to the time of the zero crossing that would arise with purely ohmic loads. Without a faulty load condition, the time of said zero crossing is within an expected value range (e.g., expected time window) which can be determined by the circuitry, the ambient conditions and by diverse motor parameters. During occurrence of the a high-side and/or low-side phase connection, it is determined whether and when the current through the switched-on high-side of low-side switch becomes greater or smaller than a predeterminable threshold wherein said time measurement can extend over one or more PWM cycles.

An electric motor is electrically commutated with the aid of circuitry, in which the phase current experiences a zero crossing at certain time points per motor phase. Owing to the inductive load portion, the time of said zero crossing of a phase current occurs at different times to the time of the zero crossing that would arise with purely ohmic loads. Without a faulty load condition, the time of said zero crossing is within an expected value range (e.g., expected time window) which can be determined by the circuitry, the ambient conditions and by diverse motor parameters. During occurrence of the a high-side and/or low-side phase connection, it is determined whether and when the current through the switched-on high-side of low-side switch becomes greater or smaller than a predeterminable threshold wherein said time measurement can extend over one or more PWM cycles.

Provided is a control device 150 for an electric motor 140 which includes multiple energization systems each including an inverter and coils corresponding to different phases, and which generates a steering assist force in an electric power steering system. Control device 150 diagnoses whether any of inverters 1A and 1B fails, and, when either of the inverters is diagnosed as having failed, reduces the output ratio of the failing inverter to 0% while increasing the output ratio of the normally operating inverter to 100% so as to prevent a drop in the total output from all the inverters after the failure-positive diagnosis. If steering operation is performed after the failure-positive diagnosis, control device 150 performs overheat protection processing for gradually lowering the limit value for the total output from all the inverters in accordance with the sensed temperature of the normally operating inverter.

A steering device includes: a plurality of electric motors 10 configured to be driven to turn wheels of a vehicle; and three or more drive systems 20 each configured to output a driving force for driving a corresponding one of the electric motors 10 to the corresponding one of the electric motors 10. A total of maximum driving forces each of which is a maximum value of a driving force of each drive system 20 of the steering device is set larger than a required driving force required to turn the wheels with the vehicle stationary, and in an event of a failure occurring in one of the three or more drive systems 20, a total of the maximum driving forces of other properly working drive systems 20 out of the three or more drive systems 20 amounts to the required driving force.

Provided is a control device for an electric motor which includes multiple energization systems each including an inverter and coils corresponding to different phases, and which generates a steering assist force in an electric power steering system. Control device diagnoses whether any of inverters 1A and 1B fails, and, when either of the inverters is diagnosed as having failed, reduces the output ratio of the failing inverter to 0% while increasing the output ratio of the normally operating inverter to 100% so as to prevent a drop in the total output from all the inverters after the failure-positive diagnosis. If steering operation is performed after the failure-positive diagnosis, control device performs overheat protection processing for gradually lowering the limit value for the total output from all the inverters in accordance with the sensed temperature of the normally operating inverter.

An electric motor is electrically commutated with the aid of circuitry, in which the phase current experiences a zero crossing at certain time points per motor phase. Owing to the inductive load portion, the time of said zero crossing of a phase current occurs at different times to the time of the zero crossing that would arise with purely ohmic loads. Without a faulty load condition, the time of said zero crossing is within an expected value range (e.g., expected time window) which can be determined by the circuitry, the ambient conditions and by diverse motor parameters. During occurrence of the a high-side and/or low-side phase connection, it is determined whether and when the current through the switched-on high-side of low-side switch becomes greater or smaller than a predeterminable threshold wherein said time measurement can extend over one or more PWM cycles.