Nsk Corporation

Kenichi Shimada

Masahiro Maeda

Yousuke Imamura

[Problem] An object of the present invention is to provide a motor controlling apparatus that comprises a single current sensor and obtains a maximal duty range that current becomes detectable with realizing size reduction, weight saving and cost reduction and an electric power steering apparatus using the same. [Means for solving the problem] A motor controlling apparatus that calculates each phase duty command value for controlling a motor current by means of control calculation, forms PWM waveforms corresponding to each phase duty command value and drives the motor based on the PWM waveforms by an inverter, comprising: a duty shift function that uniformly either increases or decreases each phase duty command value with keeping differences in each phase duty command value; and a PWM output position changing function that decides output positions of each phase PWM signal, and wherein a single current detector is connected to power supply input side or power supply output side of the inverter, timing that a PWM signal of only one phase becomes ON state or PWM signals of two phases become ON state simultaneously is generated at fixed positions of PWM periods, and the motor current is detected.

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Gunma, Japan

Kenichi Shimada