Systems and methods for swing angle estimation in an electrical power system

Patent metadata

Field	Value
Publication number	US-10024920-B2
Application number	US-201313968684-A
Country	US
Kind code	B2
Filing date	Aug 16, 2013
Priority date	Aug 16, 2013
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

In accordance with one embodiment, a method for detection of power swing for at least a first range of swing angles between an internal voltage (ES) of a source-end generator and an internal voltage (ER) of a receiving-end generator is provided. The method includes obtaining a voltage magnitude (VS) of the source-end generator, and a current magnitude (IS) of the source-end generator. The method further includes estimating a total reactance (X) between the source-end generator and the receiving-end generator, and estimating a first swing angle (θ) between the ES and the ER as a function of the obtained VS, the obtained IS and the estimated X. The method further includes detecting a power swing condition based on the estimated θ.

First claim

What is claimed is:

1. A method, comprising:
for at least a first range of swing angles between an internal voltage (E S ) of a source-end generator and an internal voltage (E R ) of a receiving-end generator:
(i) obtaining a voltage magnitude (V S ) of the source-end generator in a voltage determination (VD) module of a power swing detection device;
(ii) obtaining a current magnitude (I S ) of the source-end generator in a current determination (CD) module of the power swing detection device;
(iii) estimating a total reactance (X) between the source-end generator and the receiving-end generator based on current and power values or based on system topology and line parameters in a reactance estimation (RE) module of the power swing detection device;
(iv) estimating a first swing angle (θ) between the E S and the E R as a function of the obtained V S , the obtained I S and the estimated X in a swing angle estimation (SAE) module coupled to the VD module, the CD module and the RE module of the power swing detection device;
(v) detecting a power swing condition when a function of the estimated θ exceeds a threshold value in a detection module coupled to the SAE module of the power swing detection device;
(vi) comparing the obtained I S with a current threshold value (I min ) in a comparison module coupled to the CD module and the SAE module of the power swing detection device;
(vii) executing steps (iv) and (v), when the obtained I S is greater than or equal to the I min ; and
(viii) tripping a circuit breaker to isolate the source-end generator when the power swing condition is detected in the detection module;

wherein for at least a second range of swing angles between the E S and the E R when the obtained I S is less than the I min ;
determining a real power value (P) based on the obtained V S and the obtained I S in a real power determination (real PD) module of the power swing detection device;
determining a maximum magnitude of power (P max ) transmitted from the source-end generator to the receiving-end generator in a maximum power determination (MPD) module coupled to the comparison module of the power swing detection device;
estimating a second swing angle (θ 1 ) between the E S and the E R as a function of the determined P and the determined P max in the SAE module; and
detecting the power swing condition based on the estimated θ 1 in the detection module.

2. The method of claim 1 , wherein the step (iii) comprises estimating the X as a function of a maximum magnitude of current (I max ) determined during the power swing condition and maximum magnitude of power (P max ) determined during the power swing condition.

3. The method of claim 1 , further comprising obtaining a load angle (α) between the V S and the I S .

4. The method of claim 3 , wherein the step (iv) comprises estimating the θ as a function of the obtained α.

5. The method of claim 1 , further comprising:
determining a real power value (P) based on the obtained V S and the obtained I S ;
determining a reactive power value (Q) based on the obtained I S and the estimated X; and
estimating a rate of change of swing angle ({dot over (θ)}) as a function of the determined P and the determined Q.

6. The method of claim 5 , wherein the step (v) comprises detecting the power swing condition based on the estimated {dot over (θ)}.

7. A power swing detection device, comprising:
for at least a first range of swing angles between an internal voltage (E S ) of a source-end generator and an internal voltage (E R ) of a receiving-end generator:
a voltage determination module configured to obtain a voltage magnitude (V S ) of the source-end generator;
a current determination module configured to obtain a current magnitude (I S ) of the source-end generator;
a reactance estimation module configured to estimate a total reactance (X) between the source-end generator and the receiving-end generator based on current and power values or based on system topology and line parameters;
a swing angle estimation module configured to estimate a first swing angle (θ) between the E S and the E R as a function of the obtained V S , the obtained I S and the estimated X;
a detection module configured to detect a power swing condition when a function of the estimated θ exceeds a threshold value; and
a comparison module configured to compare the obtained I S with a current threshold value (I min ), wherein the comparison module is configured to send a deactivation signal to the swing angle estimation and detection modules for deactivation thereof when the obtained I S is less than the I min ,

wherein the detection module trips a circuit breaker and isolates the source-end generator when the power swing condition is detected.

8. The power swing detection device of claim 7 , wherein the reactance estimation module is configured to estimate the X as a function of a maximum magnitude of current (I max ) determined during the power swing condition and a maximum magnitude of real power (P max ) determined during the power swing condition.

9. The power swing detection device of claim 7 , further comprising a load angle determination module configured to obtain a load angle (α) between the V S and the I S .

10. The power swing detection device of claim 9 , wherein the swing angle estimation module is configured to estimate the θ as a function of the obtained α.

11. The power swing detection device of claim 7 , further comprising:
a real power determination module configured to determine a real power value (P) based on the obtained V S and the obtained I S ; and
a reactive power determination module configured to determine a reactive power value (Q) based on the obtained I S and the estimated X,
wherein the swing angle estimation module is configured to estimate a rate of change of swing angle ({dot over (θ)}) as a function of the determined P and the determined Q.

12. The power swing detection device of claim 11 , wherein the detection module is configured to detect the power swing condition based on the estimated {dot over (θ)}.

13. The power swing detection device of claim 7 , wherein for at least a second range of swing angles between the E S and the E R when the obtained I S is less than the I min , further comprises:
a real power determination module configured to determine a real power value (P) based on the obtained V S and the obtained I S ; and
a maximum power determination module configured to determine a maximum magnitude of power (P max ) transmitted from the source-end generator to the receiving-end generator, wherein:
the swing angle estimation module is configured to estimate a second swing angle (θ 1 ) between the E S and the E R as a function of the determined P and the determined P max , and
the detection module is configured to detect the power swing condition based on the estimated θ 1 .

14. An electrical power system, comprising:
a receiving-end generator;
a source-end generator configured to be electrically coupled to the receiving-end generator; and
a power swing detection device, comprising:
for at least a first range of swing angles between an internal voltage (E S ) of the source-end generator and an internal voltage (E R ) of the receiving-end generator:
a voltage determination module configured to obtain a voltage magnitude (V S ) of the source-end generator;
a current determination module configured to obtain a current magnitude (I S ) of the source-end generator;
a reactance estimation module configured to estimate a total reactance (X) between the source-end generator and the receiving-end generator b

Assignees

• Gen Electric

Inventors

• Pan Yan
• Premerlani William James

Classifications

• H02J3/00144 Primary

  using phasor measuring units [PMU] · CPC title

• H02H3/382

  involving phase comparison between current and voltage or between values derived from current and voltage · CPC title

• G01R21/1331

  Measuring real or reactive component, measuring apparent energy · CPC title

• G01R31/343 Primary

  in operation · CPC title

• G01R19/2513

  Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging · CPC title