Fault-tolerant field-oriented control method of five-phase interior permanent-magnet linear motor under two nonadjacent short-circuit phase faults

Patent metadata

Field	Value
Publication number	US-10574164-B2
Application number	US-201615748926-A
Country	US
Kind code	B2
Filing date	Aug 17, 2016
Priority date	Jul 26, 2016
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

The invention proposes a fault-tolerant field-oriented control method of five-phase interior permanent-magnet fault-tolerant linear motor (IPM-FTLM) with two nonadjacent short-circuit phase faults. Firstly, the extended Clark transformation matrix can be obtained according to the principle that magnetic motive force (MMF) keeps constant before and after the two-phase open-circuit faults, the constraint that the sum of healthy phase currents is zero and the adjacent two-phase current amplitude is equal. The back electric motive force (EMF) can be estimated by the transposed matrix. The nonlinear strong coupling system becomes the first-order inertia system when using the internal mode controller, the first-order inertia feed-forward voltage compensator and back-EMF observer, as the motor is with fault. Then, according to the principle that the sum of MMF of the healthy phase short-circuit compensation currents and two phases short-circuit fault currents is zero, the short-circuit compensation voltage can be obtained, and then these voltages add vector-controller output voltages, respectively. The invention not only restrains the thrust force fluctuation caused by two nonadjacent short-circuit phase faults, but also more importantly keeps the same dynamic and steady performance as the normal conditions, and also it has the constant switching frequency of voltage source inverter.

First claim

What is claimed is:

1. A fault-tolerant field-oriented control method of five-phase interior permanent magnet fault-tolerant linear motor (IPM-FTLM) with two nonadjacent short-circuit phase faults comprising:
(1) establishing the model of five-phase IPM-FTLM including a primary and a secondary magnetic element;
(2) dividing an IPM-FTLM into five phases: phase-A, phase-B, phase-C, phase-D and phase-E, each with a current; wherein a plurality of short-circuit faults occur in phase-B and phase-E and a plurality of open-circuit faults only occur in phase-B and phase-E, according to a principle of constant traveling-wave magnetic motive force (MMF) both before and after open-circuit faults occur; and wherein a sum of a number of a healthy phase current of each not faulted phase is zero, and an amplitude of adjacent phase-C and phase-D currents is equal,
wherein the healthy phase currents of fault-tolerant operation can be obtained after the open-circuit faults occur in phase-B and phase-E:

{

i
A
*

=

1.381
⁢

(

-

i
q
*

⁢

sin
⁡

(
θ
)

+

i
d
*

⁢

cos
⁡

(
θ
)

)

i
C
*

=

2.235
⁢

(

-

i
q
*

⁢

sin
(

θ
-

3
5

⁢
π

)

+

i
d
*

⁢

cos
(

θ
-

3
5

⁢
π

)

)

i
D
*

=

2.235
⁢

(

-

i
q
*

⁢

sin
(

θ
+

3
5

⁢
π

)

+

i
d
*

⁢

cos
(

θ
+

3
5

⁢

Assignees

• Univ Jiangsu

Inventors

• Zhou Huawei
• Liu Guohai
• Ji Jinghua
• Zhao Wenxiang
• Chen Qian
• Chen Long

Classifications

• H02P29/027

  the fault being an over-current · CPC title

• H02P29/032

  Preventing damage to the motor, e.g. setting individual current limits for different drive conditions · CPC title

• H02P27/04

  using variable-frequency supply voltage, e.g. inverter or converter supply voltage · CPC title

• B60K1/00

  Arrangement or mounting of electrical propulsion units (B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00) · CPC title

• H02P25/064 Primary

  of the synchronous type · CPC title