Method for analyzing magnetomotive force of windings in short primary linear machine

Patent metadata

Field	Value
Publication number	US-11463036-B2
Application number	US-202017427101-A
Country	US
Kind code	B2
Filing date	Aug 27, 2020
Priority date	Jun 24, 2020
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

The disclosure uses the Carter's coefficient to correct the equivalent electromagnetic air gap length. And the specific permeance on both sides of the primary core is obtained. Then, the permeance on both sides based on the structure of the primary core is calculated. An equation is established by using the continuity principle of flux, thereby obtaining the air gap magnetomotive force model of current-carrying conductor. The slot vector diagram of magnetomotive force in short primary linear machine is illustrated according to that in the rotating machine. Then, based on the winding arrangement and vector combination, the amplitude and phase of various spatial harmonic wave of the three-phase winding are obtained. Finally, the characteristics of average component distribution of the current-carrying conductor are adopted to obtain the pulsating magnetomotive force generated by the three-phase winding of the linear machine.

First claim

What is claimed is:

1. A method for analysing a magnetomotive force of winding in a short primary linear machine, comprising the following steps performed by a processor:
S 1 : Carter's coefficient is adopted to modify an equivalent electromagnetic air gap length, and a specific permeance on both sides of a primary core is obtained, permeances on both sides of primary iron core is obtained based on the structure of the primary core, a principle of magnetic flux continuity is adopted to establish an equation, and in this manner, an air gap magnetomotive force model of a current-carrying conductor can be obtained;
S 2 : a slot vector diagram of magnetomotive force in the short primary linear machine is illustrated according to that in a rotating machine, wherein the slot vector of magnetomotive force in short primary linear machine and each harmonic component of airgap magnetomotive force produced by the current-carrying conductor has a one-to-one correspondence;
S 3 : based on the slot vector diagram of magnetomotive force in short primary linear machine, a winding factor and phase of each pole-pair harmonic of each phase winding are calculated;
S 4 : according to the distribution characteristics of an average component of the slot magnetomotive force in the short primary linear machine and a winding arrangement, the amplitude and phase of the pulsating magnetomotive force of the short primary linear machine are analyzed and calculated,
wherein the method is applied to the short primary linear machine whose core operating at unsaturated point,
wherein the method further comprises:
modifying, by the processor, an operation of generating a linear motion of the short primary linear machine based on the winding factors and phases of each pair of pole-pair harmonics of each phase winding and the amplitude and the phase of the pulsating magnetomotive force.

2. The analysis method according to claim 1 , wherein, following the step S 3 , the method further comprises:
matrix transformation is performed on the winding factors and phases of each pair of pole-pair harmonics of each phase winding to obtain the winding coefficients factors and initial phases corresponding to a forward traveling wave component and a backward traveling wave component of each pair of pole-pair harmonic of magnetomotive force.

3. The analysis method according to claim 2 , wherein the slot vector diagram of magnetomotive force in the short primary linear machine illustrated according to that in the rotating machine in step S 2 comprises:
the magnitude and a phase of a shift vector are determined based on the relationship between the rotating machine and the short primary linear machine, the slot vector of magnetomotive force in the rotating machine and the shift vector are combined to obtain the slot vector of magnetomotive force in the short primary linear machine.

4. The analysis method according to claim 1 , wherein the slot vector diagram of magnetomotive force in the short primary linear machine illustrated according to that in the rotating machine in step S 2 comprises:
the magnitude and a phase of a shift vector are determined based on the relationship between the rotating machine and the short primary linear machine, the slot vector of magnetomotive force in the rotating machine and the shift vector are combined to obtain the slot vector of magnetomotive force in the short primary linear machine.

5. The analysis method according to claim 1 , wherein the air gap magnetomotive force model of the current-carrying conductor can be expressed as:

F
c

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(
x
)

=

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0

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(

x
c

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I

+

∑

v
=
1

∞

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K
v

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(

x
c

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I
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cos
⁡

(

2
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v
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π

L

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;

specifically,

K
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(

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Assignees

• Univ Huazhong Science Tech

Inventors

• Xu Wei
• Ge Jian
• Liu Yi
• Zhang Yaping
• Xiong Fei
• Su Jingyue

Classifications

• H02P25/06 Primary

  Linear motors · CPC title

• H02P25/064

  of the synchronous type · CPC title

• H02K41/03 Primary

  Synchronous motors; Motors moving step by step; Reluctance motors (H02K41/035 takes precedence) · CPC title

• H02P6/006

  Controlling linear motors · CPC title

• H02P25/062

  of the induction type · CPC title