Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Yoshihiro Shamoto

Hiroyuki Oyanagi

Kenji Yamada

Yasuhiro Nakai

Takaya Soma

Satoru Katoh

Kazuhito Hayashi

An electric motor control device includes an electronic control unit configured to perform switching control of a switching element of an inverter in PWM control mode when a modulation degree is less than a first predetermined value, perform switching control of the switching element in square wave control mode when the modulation degree is greater than or equal to a second predetermined value, and perform switching control of the switching element in intermediate control mode when the modulation degree is greater than or equal to the first predetermined value and less than the second predetermined value. The intermediate control mode uses a switching pattern in which, in a pulse pattern in the square wave control mode, a slit or a short pulse having the same width as the slit is formed according to whether a pulse is present at the time when a phase current crosses zero.

Electric motor control device

The first square wave control mode using the square wave pulse pattern is used when the voltage acting on the inverter is equal to or higher than the threshold voltage. On the other hand, when the voltage acting on the inverter is lower than the threshold voltage, a square wave pulse pattern is used when the rotation speed of the motor is equal to or higher than the first predetermined rotation speed that is higher than the first resonance region, and the second square wave control mode using the first switching pattern for suppressing the LC resonance in the first resonance region is used when the rotation speed of the motor is lower than the first predetermined rotation speed.

Drive device

A controller of an electrically powered vehicle includes an electronic control unit. The electronic control unit performs a switching control by a square wave control in a first switching mode when a rotation speed of the motor is equal to or higher than a first predetermined rotation speed. The electronic control unit performs the switching control by the square wave control in a second switching mode when the rotation speed of the motor is lower than the first predetermined rotation speed. The first predetermined rotation speed is a rotation speed lower than a first resonance region. The first switching mode is a mode of a switching pattern that suppresses LC resonance in the first resonance region. The second switching mode is a mode of a switching pattern that suppresses LC resonance in a second resonance region lower than the first predetermined rotation speed.

Controller of electrically powered vehicle

A control device divides 360&#xb0; corresponding to one cycle of a resolver angle into N zones, and determines whether or not a resolver angle &#x3b8; in the current cycle exceeds a division border. When determined that resolver angle &#x3b8; in the current cycle exceeds a division border, the control device calculates a time difference &#x394;T[n] between a calculation time T[n] in the immediately preceding resolver cycle and a calculation time T in the current cycle. The control device also calculates a resolver angle variation &#x394;&#x3b8;[n] with time difference &#x394;T[n] by adding 360&#xb0; to the difference between resolver angle &#x3b8; obtained in the current cycle and a resolver angle &#x3b8;[n] obtained in the immediately preceding resolver cycle. The control device then calculates a rotation speed NM by multiplying, by a coefficient K, a value obtained by dividing &#x394;&#x3b8;[n] by &#x394;T[n].

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Kounan, Japan

Yoshihiro Shamoto