Abstract: An electric power steering apparatus includes a control substrate that controls a poly-phase motor having a multi-system motor winding, including a temperature sensor that detects a substrate temperature of said control substrate; and a coil temperature estimating section that obtains coil calorific values of respective phases of said poly-phase motor and a substrate calorific value of said control substrate by a motor current of said phase, and estimates a coil temperature of said phase by said coil calorific value, said substrate calorific value and said substrate temperature based on a heat transfer phenomenon between said respective phases that is caused by a difference in temperature between coils of said respective phases and a heat transfer phenomenon between said coil and said control substrate.

Abstract: An electric power steering apparatus that enables more precise estimation of a coil temperature by considering a heat transfer phenomenon between a control substrate and a poly-phase coil in addition to a heat transfer phenomenon between respective phases of the coil. The apparatus includes a control substrate that controls a poly-phase motor, a temperature sensor that detects a substrate temperature of the control substrate and a coil temperature estimating section that estimates coil temperatures of respective phases of the poly-phase motor by a motor current of the phase and the substrate temperature based on a heat transfer phenomenon between the respective phases that is caused by a difference in temperature between coils of the respective phases and a heat transfer phenomenon between the coil and the control substrate.

Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus that enables more precise estimation of a coil temperature by considering a heat transfer phenomenon between a control substrate and a coil in addition to a heat transfer phenomenon between respective phases of a poly-phase coil for a poly-phase motor having a multi-system motor winding, and enables the estimation of the coil temperature even when an abnormality occurs in any of the systems.

Abstract: An electric power steering apparatus that enables more precise estimation of a coil temperature by considering a heat transfer phenomenon between a control substrate and a poly-phase coil in addition to a heat transfer phenomenon between respective phases of the coil. The apparatus includes a control substrate that controls a poly-phase motor, a temperature sensor that detects a substrate temperature of the control substrate and a coil temperature estimating section that estimates coil temperatures of respective phases of the poly-phase motor by a motor current of the phase and the substrate temperature based on a heat transfer phenomenon between the respective phases that is caused by a difference in temperature between coils of the respective phases and a heat transfer phenomenon between the coil and the control substrate.

Abstract: [Problem] An object of the present invention is to provide an electric power steering apparatus that enables more precise estimation of a coil temperature for a poly-phase motor by considering a heat transfer phenomenon between a control substrate and a coil in addition to a heat transfer phenomenon between the coils. [Means for solving the problem] An electric power steering apparatus that comprises a control substrate that controls a poly-phase motor having two-system motor windings, comprises a temperature sensor that detects a substrate temperature of the control substrate, and a coil temperature estimating section that estimates all coil temperatures by all motor currents of the poly-phase motor and the substrate temperature based on a heat transfer phenomenon between all coils that is caused by a difference in temperature between the all coils and a heat transfer phenomenon between the coil and the control substrate.