Single-phase reclosing method, device and storage medium for AC/DC system

Patent metadata

Field	Value
Publication number	US-11677231-B2
Application number	US-202117372269-A
Country	US
Kind code	B2
Filing date	Jul 9, 2021
Priority date	Jul 15, 2020
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

The present disclosure is directed to a single-phase reclosing method, device and storage medium for AC/DC system. The method comprises: acquiring three-phase voltages at inverter-side AC bus close to the transformer, three-phase currents measured at the outlet of inverter-side AC line and three-phase voltages at inverter-side AC bus far from the transformer; calculating the energy calculation value and energy operation value of the fault line; identifying the fault nature of fault line within the maximum time delay, according to the energy calculation value and energy operation value of fault line and an energy criterion of transient/permanent fault; issuing a reclosing control signal based on the fault nature of fault line to realize effective reclosing of the fault line.

First claim

What is claimed is:

1. A single-phase reclosing method for an AC/DC system, comprising:
acquiring three-phase voltages u am , u bm , u cm at an inverter-side AC bus close to a transformer three-phase currents i a , i b , i c measured at an outlet of an inverter-side AC line, and three-phase voltages u an , u bn , u cn at the inverter-side AC bus far from the transformer;
calculating an energy calculation value E cal and an energy operation value E DZ of a fault line, based on the acquired three-phase voltages u am , u bm , u cm inverter-side AC bus close to the transformer the three-phase currents i a , i b , i c measured at the outlet of the inverter-side AC line, and the three-phase voltages u an , u bn , u cn at the inverter-side AC bus far from the transformer;
identifying a fault nature of the fault line within a maximum time delay, according to the energy calculation value E cal and the energy operation value E DZ of the fault line and an energy criterion of transient or permanent fault;
issuing a reclosing control signal based on the fault nature of the fault line to realize an effective reclosing of the fault line.

2. The single-phase reclosing method according to claim 1 , wherein a formula used to calculate the energy calculation value E cal is:

E
cal

=

∫

t
1

t
2

[

(

i
jm

(

t
-

T
4

)

·

u
jm

(
t
)

-

i
jn

(

t
-

T
4

)

·
u

(
jn

⁢
t

)

)

-

i
jn

(

t
-

T
4

)

·

(

u
jm

(
t
)

-

u
jn

(
t
)

)

]

⁢
dt

⁢

where

⁢

i
jm

=

C
m

2

·

d
⁡
(

u
xm

(
t
)

+

u
ym

(
t
)

-

2
⁢

u
jm

(
t
)

)

Assignees

• Univ North China Electric Power

Inventors

• Ma Jing
• Liu Chen
• Zhang Jiaming
• Zhang Min

Classifications

• H02H3/06 Primary

  with automatic reconnection · CPC title

• H02H1/0007

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• G01R31/52

  Testing for short-circuits, leakage current or ground faults · CPC title

• H02H7/26

  Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured (locating faults in cables G01R31/08) · CPC title

• H02H7/125 Primary

  for rectifiers · CPC title