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Power conversion device and auto-tuning method therefor

A power conversion device and automatic tuning technology, which is applied in the direction of AC motor control, electrical components, control systems, etc., can solve problems such as difficulty in setting, and achieve the effect of high torque

Inactive Publication Date: 2018-03-27
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 field current is increased, magnetic flux saturation occurs, so it is difficult to set a value that expresses appropriate motor characteristics in vector control

Method used

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  • Power conversion device and auto-tuning method therefor
  • Power conversion device and auto-tuning method therefor
  • Power conversion device and auto-tuning method therefor

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Embodiment 1 relates to detection of mutual inductance M in consideration of magnetic saturation based on V / f control.

[0045] figure 1 A configuration diagram showing a power conversion device according to Embodiment 1 of the present invention.

[0046] The induction motor 1 generates torque by a magnetic flux generated by a current component of a magnetic flux axis (d axis) and a current component of a torque axis (q axis) perpendicular to the magnetic flux axis.

[0047] Power converter 2 outputs and three-phase AC voltage command value V u * , V v * , V w * In direct proportion to the voltage value, adjust the output voltage value and rotation frequency value of the induction motor 1.

[0048] The DC power supply 2 a supplies a DC voltage to the power converter 2 .

[0049] The current detector 3 outputs the three-phase AC current I of the induction motor 1 u , I v , I w The detection value of I uc , I vc , I wc . The current detector 3 can also dete...

Embodiment 2

[0074] Example 2 involves generating tables of mutual inductance and field current.

[0075] image 3 It is a configuration diagram of a power conversion device according to Embodiment 2 of the present invention.

[0076] In Embodiment 1, the ratio of the output voltage to the output frequency of the V / f control unit (hereinafter referred to as V / f ratio) was set to a fixed value, but in this embodiment, the V / f ratio is changed in multiple steps.

[0077] In the figure, symbols 1~4, 6~8 and figure 1 of the same.

[0078] Figure 4 It is a block diagram of the V / f control part 5'.

[0079] In the V / f control unit 5', the V / f ratio (V / f_gain) that changes in multiple stages is set as the variable 5'a, and the speed command value ω r * Multiply, and output the q-axis voltage command value V qc * . In addition, for the d-axis voltage command value V dc * The output is set to zero at the constant 5'b.

[0080] exist Figure 5 An example of the output signal of the var...

Embodiment 3

[0093] Figure 8 It is a configuration diagram of a power conversion device according to Embodiment 3 of the present invention.

[0094] Embodiment 1 involves estimating mutual inductance M, embodiment 2 involves generating a table of mutual inductance and excitation current, and embodiment 3 applies the table generated in embodiment 2 to a power conversion device based on speed sensorless vector control.

[0095] Figure 8 Among them, symbols 1~4, 6, 8 and figure 1 of the same.

[0096] The speed estimation unit 10 based on the q-axis voltage command value V qc *** , q-axis current detection value I qc , output frequency value ω 1 * and the electrical constant of the induction motor 1 (R 1 , R 2 ') and the d-axis secondary magnetic flux command value φ of the d-axis current and magnetic flux command setting unit 13 2d * , output the estimated speed value ω of the induction motor 1 r ^ .

[0097] The slip frequency calculation unit 11 is based on the current comm...

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Abstract

Provided is a power conversion device that achieves auto-tuning of mutual inductance M while taking into account magnetic saturation, and achieves automatic setting pertaining to a command value for excitation current, and that, in a vector control operation, achieves high torque in a stable manner even in an extremely low-speed region. This auto-tuning method for a power conversion device that drives an induction motor has: a step wherein, in an auto-tuning mode, a V / f control unit that outputs a voltage command value for the induction motor changes the ratio of the output voltage / output frequency of the induction motor, thereby changing the voltage command value in multiple stages; a step wherein a current detection means detects the excitation current, which changes in multiple stages;and a step wherein a mutual inductance calculation unit calculates the reactive power on the basis of the voltage command value, the current detection values, and a speed command value, and estimatesfrom the reactive power the mutual inductance of the induction motor, which changes over multiple stages.

Description

technical field [0001] The present invention relates to a power conversion device for driving an induction motor and an automatic tuning method thereof. Background technique [0002] In an induction motor for a certain application, it is required to output high torque in a low speed range such as 5 Hz or less, and in order to solve the torque shortage in the low speed range, the field current is increased. However, when the field current is increased, magnetic flux saturation occurs, so it is difficult to set a numerical value that expresses appropriate motor characteristics in vector control. Therefore, in a power conversion device for driving an induction motor, it is necessary to set an appropriate magnetic flux command in consideration of magnetic flux saturation. [0003] In Patent Document 1, in the equivalent no-load test method of an induction machine, it is described that the excitation current equivalent to the no-load test can be detected under load conditions, a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02P27/06
CPCH02P21/14H02P27/047
Inventor 户张和明井堀敏富田浩之中村敦彦小沼雄作杉本卓也岩路善尚神谷昭范
Owner HITACHI IND EQUIP SYST CO LTD
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