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Step-out detection method and power conversion device

A technology of a power conversion device and a detection method, which is applied in the direction of monitoring commutation, electronic commutator, electrical components, etc., can solve problems such as difficult detection of out-of-step, and achieve high reliability

Active Publication Date: 2015-09-30
HITACHI IND EQUIP SYST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, when the position detector is not used, it is difficult to perform drive control to completely prevent out-of-synchronization, and it is difficult to detect the occurrence of out-of-synchronization

Method used

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  • Step-out detection method and power conversion device
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  • Step-out detection method and power conversion device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] figure 1 This is an example of the embodiment configuration of the power conversion device of the first embodiment.

[0023] The three-phase AC voltage input from the three-phase AC power supply 1 is rectified by a rectification circuit (switching circuit) 2 and smoothed by a smoothing circuit 3 .

[0024] The conversion circuit 4 converts the voltage smoothed by the smoothing circuit 3 , that is, the DC voltage into a three-phase AC voltage, and applies it to the three-phase AC synchronous motor 6 .

[0025] The PWM controller 7 outputs a switching control signal for controlling switching on and off of the switching circuit 4 to apply a voltage based on a voltage command to the three-phase AC synchronous motor 6 .

[0026] The current detector 5 detects the three-phase AC current flowing in the three-phase AC synchronous motor 6 . It is also possible to detect only two phases, and since the sum of the three-phase alternating current is zero, the remaining one phase i...

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PUM

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Abstract

Provided is a highly reliable step-out detection method which can be unaffected by noise without use of a position detector in a power conversion device for controlling the drive of a synchronous motor. A power conversion device comprises: a switching circuit for converting DC power to AC power; a PWM controller for outputting a switching control signal to control turning the switching circuit on and off on the basis of a voltage command; a current detector for detecting a current flowing in the synchronous motor; an axis error estimator for estimating the axis error between a control axis and the rotor pole axis of the synchronous motor on the basis of the voltage command and the current detected by the current detector; a frequency component extractor for extracting any frequency component of the axis error estimated by the axis error estimator; and a step-out determination unit for determining whether or not there is step-out on the basis of the frequency component extracted by the frequency component extractor.

Description

technical field [0001] The present invention relates to an out-of-step detection method and a power conversion device in drive control of a synchronous motor without using a rotational position detector. Background technique [0002] In driving a synchronous motor typified by a permanent magnet synchronous motor, it is necessary to control current according to the rotor magnetic pole position of the synchronous motor, and a power conversion device is used for this control. The rotor magnetic pole position information is indispensable for the above drive control, and a position detector is generally used to detect the rotor magnetic pole position. However, due to problems such as the price of the position detector and environmental tolerance, various methods of driving the synchronous motor by estimating the rotor magnetic pole position from the voltage and current of the synchronous motor have been proposed in recent years. [0003] In the drive of a synchronous motor, if t...

Claims

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Application Information

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IPC IPC(8): H02P27/06
CPCH02P2203/11H02P2207/05H02P6/18H02P6/12H02P29/021H02P29/0241H02P2203/09
Inventor 小沼雄作
Owner HITACHI IND EQUIP SYST CO LTD