Renesas Electronics Corporation

Reiji Yamasaki

Yutaka Ono

Yoshitaro Kondo

In a sensorless control of a motor, due to the characteristic of a response frequency, an induced voltage, a magnetic pole position estimation gain, a current control gain, and a speed control gain are closely related. An object of the invention is to enable the induced voltage and the frequency characteristic of a magnetic pole position estimation system to be clearly designed and to theoretically and quantitatively design all of the control gains necessary for the sensorless control so as to solve a problem that a method of designing those parameters cannot be established and the parameters have to be adjusted in a try and error manner. A control device has an estimator estimating an estimation induced voltage and a phase error of a motor by applying an induced-voltage observer and a controller controlling the motor on the basis of the estimation induced voltage and the phase error.

Control device

A calculation apparatusincludes an encoderconfigured to detect rising edges of PWM signals having at least three or more phases in each of the phases, and a registerconfigured to store, at a timing after the PWM signals having the respective phases rise and after AD conversion of a current value of a drive signal of a motor obtained by the PWM signals, a difference value between the AD-converted current value and a previous AD-converted current value for each phase.

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Tokyo, Japan

Reiji Yamasaki