Unlock instant, AI-driven research and patent intelligence for your innovation.

A Negative Damping Detection Method of Excitation System Based on Oscillation Energy Injection

A technology of excitation system and oscillating energy, applied in the direction of measuring electricity, measuring devices, measuring electrical variables, etc., can solve problems such as low frequency oscillation of power system

Inactive Publication Date: 2016-09-21
SICHUAN UNIV
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0013] Negative damping of excitation system is the main cause of low frequency oscillation in power system

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A Negative Damping Detection Method of Excitation System Based on Oscillation Energy Injection
  • A Negative Damping Detection Method of Excitation System Based on Oscillation Energy Injection
  • A Negative Damping Detection Method of Excitation System Based on Oscillation Energy Injection

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0122] K=0

[0123] The excitation amplification factor of 0 means that the excitation adjustment is not performed, and the excitation voltage does not fluctuate, Δu f (t)=0. In this case the excitation system neither injects nor absorbs oscillation energy; that is to say, it provides neither positive nor negative damping to the system. This is the damping ratio of the system ζ = 0.021.

[0124] K=10

[0125] The excitation magnification is K=10, see Figure 4(a)-Figure 4(b) , the excitation voltage and excitation current when K = 10, and the excitation voltage and excitation current waveforms from 0 to 7.5 seconds at the beginning of the simulation are given.

[0126] The data from 2.5 to 7.5 seconds were selected for analysis. In this time period, the approximate number of oscillations is m=9, and the sampling period Δt=0.01 seconds. According to equations (17) and (18), the oscillation frequency f of the main oscillation mode satisfies 0.6Hz≤f≤1.2Hz. Select the identi...

Embodiment 2

[0134] K=30

[0135] The excitation magnification is K=30, Figure 6(a)-Figure 6(b) The excitation voltage and excitation current waveforms from 0 to 7.5 seconds at the beginning of the simulation are given.

[0136] The data from 2.5 to 7.5 seconds were selected for analysis. In this time period, the approximate number of oscillations is m=9, and the sampling period Δt=0.01 seconds. According to equations (17) and (18), the oscillation frequency f of the main oscillation mode satisfies 0.6Hz≤f≤1.2Hz. Select the identification program order The identification program order P=8, Table 3 and Table 4 respectively give the TLS-Esprit analysis results of the excitation voltage and excitation current.

[0137] Table 3 Analysis results of excitation voltage TLS-Esprit when K=30

[0138]

[0139] Table 4 Analysis results of excitation current TLS-Esprit when K=30

[0140]

[0141] Select an oscillation mode whose oscillation frequency satisfies 0.6Hz≤f≤1.2Hz, reconstruct the...

Embodiment 3

[0144] K=50

[0145] The excitation magnification is K=50, Figure 8(a)-Figure 8(b) The excitation voltage and excitation current waveforms from 0 to 7.5 seconds at the beginning of the simulation are given.

[0146] The data from 2.5 to 7.5 seconds were selected for analysis. In this time period, the approximate number of oscillations is m=9, and the sampling period Δt=0.01 seconds. According to equations (17) and (18), the oscillation frequency f of the main oscillation mode satisfies 0.6Hz≤f≤1.2Hz. Select the identification program order The identification program order P=8, Table 5 and Table 6 respectively give the TLS-Esprit analysis results of the excitation voltage and excitation current.

[0147] Table 5 TLS-Esprit analysis results of excitation voltage when K=50

[0148]

[0149] Table 6 Analysis results of excitation current TLS-Esprit when K=50

[0150]

[0151] Select an oscillation mode whose oscillation frequency satisfies 0.6Hz≤f≤1.2Hz, reconstruct the...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a negative damping detection method of an excitation system based on oscillation energy injection, and relates to the technical field of power system dynamic stability. The oscillation energy injection into the excitation system is given by the formula Calculation; through the identification algorithm, only the oscillation component of the oscillation frequency concerned is extracted for calculation; the positive and negative of the oscillation energy injection is used to determine the negative and positive of the excitation system damping. The directly measured excitation voltage uf and excitation current if of the generator are used to detect the excitation system damping, avoiding the reconstruction of the internal variables of the generator, so the calculation is simple; because the internal parameters of the generator do not need to be used, it is avoided that the parameters of the generator are different. The error caused by the accuracy, so the calculation is more accurate. Extract the excitation voltage and excitation current during the oscillation period from the database of the generator monitoring system to analyze the damping characteristics of the excitation system; it can also be programmed as a subroutine and integrated in the generator monitoring system.

Description

technical field [0001] The invention relates to the technical field of power system dynamic stability, in particular to a method for detecting negative damping of an excitation system based on oscillation energy injection. Background technique [0002] In modern power systems, the use of fast excitation devices with high amplification factors is one of the main causes of low frequency oscillations. The excitation device may generate a negative damping torque on the generator rotor under special operating conditions, resulting in generator oscillation. [0003] On the other hand, the excitation system is also the key to suppress low-frequency oscillation. A Power System Stabilizer (PSS) is being installed in the excitation system to generate an additional excitation reference signal by feeding back the generator speed, machine terminal frequency or generator power through filtering, amplification, and phase compensation. For the excitation device, the excitation voltage is ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G01R31/00
Inventor 刘天琪杨毅强王峰
Owner SICHUAN UNIV