Inverter apparatus, method of controlling inverter apparatus, and electric motor drive system

摘要

Provided is an inverter apparatus 20 configured to switch a current winding to an optimal winding when a rotation speed of a rotor of an AC electric motor 40 is within a hysteresis region defined by first and second switch timings for switching a state of an armature winding between a first winding and a second winding and when the current winding differs from the optimal winding.

主权项

1. An inverter apparatus comprising:
a winding switching signal generator configured to output a winding switching signal having hysteresis characteristics for switch timings of a first winding and a second winding, which are determined based on a rotation speed of a rotor of an AC electric motor, to a winding switch configured to switch connection of an armature winding so that a state of the armature winding is interchangeably switched between the first winding and the second winding, wherein the winding switching signal generator comprises:
a hysteresis region judging section configured to judge whether or not the rotation speed is within a hysteresis region defined by a first switch timing and a second switch timing;a winding comparator configured to judge, when the rotation speed is within the hysteresis region, whether or not a current winding is the same as an optimal winding that is set in advance; anda winding switching signal output section configured to output, when the rotation speed is within the hysteresis region and when the current winding differs from the optimal winding, the winding switching signal so that the current winding is switched to the optimal winding, and the inverter apparatus is connected to the armature winding of the AC electric motor, and is configured to control the AC electric motor.