Decomposition-coordination voltage control method for wind power to be transmitted to nearby area via flexible DC

Patent metadata

Field	Value
Publication number	US-11228179-B2
Application number	US-202016848654-A
Country	US
Kind code	B2
Filing date	Apr 14, 2020
Priority date	Oct 17, 2019
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

The present disclosure proposes a decomposition-coordination voltage control method for wind power to be transmitted to a nearby area via flexible DC. The method includes: initializing parameters; sending the parameters to wind power farms; for each of the wind power farms, establishing a voltage control optimization sub-model; solving the voltage control optimization sub-model to obtain a first optimal result; for the control center, establishing a voltage control optimization main model; solving the voltage control optimization main model to obtain a second optimal result; calculating a determination index based on the first optimal result and the second optimal result; and determining whether the determination index is convergent to an admissible value, if no, updating the parameters and returning to establishing the voltage control optimization sub-model.

First claim

What is claimed is:

1. A decomposition-coordination voltage control method for wind power to be transmitted to a nearby area via flexible DC, comprising:
initializing parameters comprising the number of iterations, a set value of a flexible direct voltage issued by a control center, a primary penalty coefficient and a secondary penalty coefficient;
sending the parameters to wind power farms, wherein the wind power farms comprises equivalent wind power farms and wind power farms directly connected to the flexible DC, and the equivalent wind power farms are equivalent to wind power farms connected to the flexible DC via a collection station;
for each of the wind power farms, establishing a voltage control optimization sub-model based on a value of voltage at each node in the wind power farm, a set value of the voltage at each node in the wind power farm, a set value of a flexible direct voltage required in the wind power farm;
solving the voltage control optimization sub-model to obtain a first optimal result;
for the control center, establishing a voltage control optimization main model based on the first optimal result, the primary penalty coefficient and the secondary penalty coefficient;
solving the voltage control optimization main model to obtain a second optimal result;
calculating a determination index based on the first optimal result and the second optimal result; and
determining whether the determination index is convergent to an admissible value, if no, updating the parameters and returning to establishing the voltage control optimization sub-model.

2. The method of claim 1 , wherein initializing the parameters comprising the number of iterations, a set value of a flexible direct voltage issued by a control center, a primary penalty coefficient and a secondary penalty coefficient comprises:
initializing the parameters by:
l=1
V vsc l =1 ,
α w l =β w l

where l represents the number of iterations, V vsc l represents a set value of a flexible direct voltage issued by the control center at the l th iteration, α w l and β w l represent a primary penalty coefficient and the secondary penalty coefficient for the w th wind power farm at the l th iteration respectively.

3. The method of claim 2 , wherein for each of the wind power farms, establishing the voltage control optimization sub-model comprises:
establishing an objective function for the w th wind power farm, which is represented by:

min
⁢

∑

i
=
1

N
w

⁢

⁢

(

V

i
,
w

-

V

i
,
w

ref

)

2

+

α
w
l

⁡

(

V

vsc
,
w

-

V
vsc
l

)

+

β
w
l

⁡

(

V

vsc
,
w

-

V
vsc
l

)

2

,

where V i,w represents a value of voltage at the i th node in the w th wind power farm, V i,w ref represents a set value of the voltage at the i th node in the w th wind power farm, N w represents the number of nodes in the w th wind power farm, and V vsc,w represents a set value of a flexible direct voltage required in the w th wind power farm.

4. The method of claim 3 , wherein for each of the wind power farms, establishing the voltage control optimization sub-model comprises:
establishing constraints for the w th wind power farm, comprising an equation constraint for a node voltage, an equation constraint for active power produced by the flexible DC, an equation constraint for reactive power produced by the flexible DC, an adjustment constraint for wind turbines in the wind power farm, an adjustment constraint for reactive power compensation devices in the wind power farm, an adjustment constraint for the flexible direct voltage, and a constraint for node voltage security, wherein,
the equation constraint for a node voltage is represented by:

⁢

V

i
,
w

=

V

i
,
w

0

+

Δ
⁢

V

i
,
w

Δ
⁢

V

i
,
w

=

Assignees

• Univ Tsinghua
• State Grid Beijing Electric Power Co
• State Grid Jibei Electric Power Company

Inventors

• Wang Bin
• Ji Hongquan
• Du Yanling
• Guo Qinglai
• Yu Xijuan
• Liu Haitao
• Sun Hongbin
• Wang Guannan
• Jiang Mang
• Ge Huaichang
• Wu Wenchuan

Classifications

• H02J2101/28

  Wind energy · CPC title

• H02J3/16 Primary

  by adjustment of reactive power · CPC title

• H02J3/36

  Arrangements for transfer of electric power between AC networks via high-voltage DC [HVDC] links; Arrangements for transfer of electric power between generators and networks via HVDC links · CPC title

• H02P2101/15

  for wind-driven turbines · CPC title

• H02J3/381 Primary

  Dispersed generators · CPC title