Kabushiki Kaisha Yaskawa Denki

Michihiko Zenke

Katsutoshi Yamanaka

Mitsujiro Sawamura

Toshihiro Sawa

Ryuichirou Tominaga

Noritaka Koga

Noriaki Iwabuchi

Tuneo Kume

Masanobu Miyazato

In a power converting apparatus including a capacitor connected in series which serves to divide a DC voltage, and a PWM inverter bridge for converting the DC voltage into an AC phase voltage having three electric potentials of a positive voltage, a negative voltage and an intermediate voltage in a plurality of phases, a zero voltage period generator () is switched by signal switching devices (to) when a load current reaches a first overcurrent level based on the detection of an overcurrent detector (), and there is provided a zero voltage period having an intermediate voltage in which output phase voltages having all phases of the power converting apparatus become the intermediate voltages, thereby carrying out a current limitation. With an inexpensive structure, consequently, a rapidly increased current in an inverter can be instantaneously suppressed at time of the detection of an overcurrent.

Power inverter

D.C. reactor

An inverter driving method for has an arrangement polyphase induction motor, for altering a plurality of winding connections of the motor and a storage arrangement for a plurality of motor control constant groups preset corresponding to the respective winding connections so as to perform optimal vector control. When the classification of the winding connection is selected, one set of motor control constant groups corresponding to the winding connection is read out of the storage arrangement and applied to a control unit of the induction motor as control constants.

Inverter driving method for induction motors

Growing community of inventors

Fukuoka, Japan

Michihiko Zenke