Hitachi, Ltd.

Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi Car Engineering Co., Ltd.

Hitachi Appliances, Inc

Kentaro Oi

Kazuaki Tobari

Yoshitaka Iwaji

Mitsuo Sasaki

Shigehisa Aoyagi

Yasuo Notohara

Wataru Hatsuse

Dongsheng Li

Tatsuo Matsumura

Yuuji Funayama

The invention relates to a speed control method of a magnetic motor and is capable of providing a speed controller of the magnetic motor realizing highly stable, highly efficient and highly responsive control characteristics even around critical torque of the motor. When an excessive torque command value (or a q-axis commanded current value) greater than a torque maximum value (or a q-axis current) that can be outputted by the motor is required, an input of speed control is limited so that the q-axis commanded current value does not increase up to a limit value.

Speed controller of magnetic motor

When output voltage Vof an electric power converter reaches a prescribed voltage V*, a difference between Vand V*is integrated to correct a commanded torque to &#x3c4;o* (&#x3c4;*=&#x3c4;o*+&#x394;&#x3c4;).

Torque controller for permanent magnet synchronous motor

A motor control apparatus which controls an output voltage reference for an inverter driving a permanent magnet synchronous motor based on d-axis and q-axis current references, d-axis and q-axis current detected values, and a computed frequency value. When a torque reference specifying torque greater than maximum torque that the motor can output is input, a limit value for a phase angle that is a deviation between a rotation phase reference of control and a rotation phase value of the motor is varied depending on a quantity of the predetermined state.

Field weakening control apparatus for permanent magnet motor and electric power steering using same

Growing community of inventors

Hitachinaka, Japan

Kentaro Oi