Patent ID: 6677724
Filing Date: 2004-01-13
Classification: H02P

Abstract:
An initial magnetic pole estimating apparatus for an AC synchronous motor, equipped in an AC synchronous motor controller comprising speed control means for calculating a command torque, command current, from a command speed, current control means for driving the AC synchronous motor in accordance with the command torque, command current, and a PWM power converter, said initial magnetic pole estimating apparatus characterized by having:speed deviation calculating means for subtracting a detected speed from said command speed generated by command speed pattern generating means to calculate a speed deviation; a speed gain control unit for multiplying said speed deviation by a speed gain to calculate a command torque, command current; mode section determining means for determining a mode section, a first cyclic section and a second cyclic section, from said command speed; a mode switch for switching a mode section to any of said first cyclic section and said second cyclic section in accordance with a result in said mode section determining means; data acquisition speed section determining means for determining whether said command speed is in a data acquisition speed section when said first cyclic section is selected; a first command torque calculating means, first command current calculating means, for calculating first command torque data, first command current data, from said command torque, said command current, in said determined data acquisition speed section; data acquisition speed section determining means for determining whether said command speed is in said data acquisition speed section when said second cyclic section is selected; second command torque calculating means, second command current calculating means, for calculating second command torque data, second command current data, from said command torque, said command current, in said determined data acquisition speed section; and estimated initial magnetic pole calculating means for calculating an estimated initial magnetic pole position using information on said first command torque data, said first command current data, and said second command torque data, said second command current data.