Granted Patent B2

US 12,438,379 · App. 18/924,276 · Granted Oct 7, 2025

Inventors: Guoteng Wang (Hangzhou, CN); Wentao Liu (Hangzhou, CN); Ying Huang (Hangzhou, CN); Yan Li (Guangzhou, CN); Baorong Zhou (Guangzhou, CN); Ye Zhang (Guangzhou, CN); Wangqianyun Tang (Guangzhou, CN); Zheng Xu (Hangzhou, CN)

Assignees: ZHEJIANG UNIVERSITY; CHINA SOUTHERN POWER GRID CSG ELECTRIC POWER RESEARCH INSTITUTE; China Southern Power Grid Co., Ltd.

H02J3/40G01R31/52H02J2203/20

Abstract

Claims (236)

1. A method for enhancing transient stability of a renewable energy power system, comprising:

(1) constructing an external subsystem corresponding to the renewable energy power system; and constructing a first matrix corresponding to the external subsystem based on voltage control; wherein the first matrix is a matrix expression of the external subsystem under an ideal voltage control condition;

(2) generating a second matrix corresponding to the renewable energy power system; and constructing a transient stability Lyapunov function corresponding to the renewable energy power system in real time based on the first matrix and the second matrix; wherein the second matrix is a matrix expression of the external subsystem under an actual voltage control condition; and

(3) generating a first control signal corresponding to the renewable energy power system based on Lyapunov's second method; and detecting, by at least one sensor of the renewable energy power system, a deviation of an output voltage from a predetermined threshold, and adjusting, by a control system of an inverter, a voltage reference value of the inverter in real time based on the first control signal, thereby controlling and enhancing transient stability of the renewable energy power system; wherein the first control signal is an adaptive voltage control signal of the renewable energy power system.

2. The method of claim 1 , wherein step (1) further comprises:

constructing a grid-forming inverter corresponding to the renewable energy power system; and creating at least three control loops corresponding to the grid-forming inverter; wherein the at least three control loops comprise a virtual synchronization loop, a current inner loop, and a current outer loop; and

generating an output current function corresponding to an output power of the grid-forming inverter; and establishing a nonlinear system model corresponding to the renewable energy power system based on the output current function.

3. The method of claim 2 , wherein the output power of the grid-forming inverter is obtained through the following formula:

P

si

=

u

sd

⁢

i

⁢

i

sd

⁢

i

+

u

sq

⁢

i

⁢

i

sq

⁢

i

=

R

ii

⁢

(

i

sd

⁢

i

2

+

i

sq

⁢

i

2

)

+

∑

j

=

1

,

j

≠

i

N

[

R

ij

(

i

sq

⁢

j

⁢

i

sd

⁢

i

-

i

sd

⁢

i

⁢

i

sq

⁢

i

)

+

X

ij

(

i

sd

⁢

i

⁢

i

sd

⁢

j

+

i

sq

⁢

i

⁢

i

sq

⁢

j

)

]

⁢

sin

⁢

δ

ij

+

∑

j

=

1

,

j

≠

i

N

[

R

ij

(

i

sd

⁢

j

⁢

i

sd

⁢

i

+

i

sq

⁢

i

⁢

i

sq

⁢

i

)

+

X

ij

(

i

sq

⁢

i

⁢

i

sd

⁢

j

-

i

sq

⁢

i

⁢

i

sq

⁢

j

)

]

⁢

cos

⁢

δ

ij

;

wherein P si represents an output power of an i-th grid-forming inverter, i sdi represents a d-axis component of an actual output current of the i-th grid-forming inverter, i sqi represents a q-axis component of the actual output current of the i-th grid-forming inverter, u sdi represents a d-axis component of a bus voltage of the i-th grid-forming inverter, u sqi represents a q-axis component of the bus voltage of the i-th grid-forming inverter, i sdj represents a d-axis component of an actual output current of a j-th grid-forming inverter, i sqi represents a q-axis component of the actual output current of the j-th grid-forming inverter, R ij represents a real part of an element in an i-th row and a j-th column of an impedance matrix, R ij represents a real part of an element in the i-th row and an i-th column of the impedance matrix, X ij represents an imaginary part of the element in the i-th row and the j-th column of the impedance matrix, and δ ij represents an angle difference between the i-th grid-forming inverter and the j-th grid-forming inverter.

4. The method of claim 1 , wherein step (1) further comprises:

obtaining a second control signal corresponding to the external subsystem under the ideal voltage control condition; wherein the second control signal is obtained through the following formula:

v

=

K

a

T

⁢

ξ

+

K

c

T

⁢

C

;

wherein v represents the second control signal; C represents a coefficient matrix; ξ represents an external variable vector of the renewable energy power system; and K a and K c are coefficient matrices of an ideal control scheme.

5. The method of claim 4 , wherein the external subsystem is represented by:

ξ

˙

=

A

⁢

ξ

+

Bv

+

C

;

wherein ξ represents the external variable vector of the renewable energy power system; A, B, and C are coefficient matrices; and v represents an auxiliary control signal for individual inverters in the renewable energy power system.

6. The method of claim 1 , wherein step (3) further comprises:

obtaining the first control signal by calculation through the following formula:

u

=

A

⁢

ξ

+

B

⁢

K

^

a

T

⁢

ξ

+

B

⁢

K

^

c

T

⁢

C

;

wherein u represents the first control signal; A, B, and C are coefficient matrices; ξ represents an external variable vector of the renewable energy power system; and {circumflex over (K)} a and {circumflex over (K)} c are coefficient matrices that satisfy a Lyapunov stability condition.

7. The method of claim 1 , further comprising:

after step (3), generating a short-circuit fault data corresponding to the renewable energy power system, and verifying transient stability of the renewable energy power system in real time based on the short-circuit fault data.

Assignments (2)

Continuity (2)

References Cited (14)