A Fast Frequency Estimation Method for Three-Phase Power System

A three-phase power and frequency estimation technology, applied in the direction of frequency measurement devices, etc., can solve the problems of slow frequency estimation, no consideration of negative sequence voltage components, large errors, etc.
CN110244120BActive Publication Date: 2020-07-07SOUTHWEST JIAOTONG UNIV
14 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
SOUTHWEST JIAOTONG UNIV
Publication Date
2020-07-07

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
  • Figure 3
    Figure 3
Patent Text Reader

Abstract

A fast frequency estimation algorithm for a three-phase power system, the main steps are: A. Collect and transform to obtain a complex voltage signal v(n); B. Obtain the estimated value of the complex voltage signal at the next moment, C. Calculate the complex voltage signal The error D of , calculate the expected value of square error p(n)=βp(n‑1)+e 2 (n), and then calculate the step size at the current moment μ(n)=αμ(n‑1)+γe 2 (n), and then calculate the standard weight coefficient h(n+1)=h(n)+μ(n)[3p(n)‑e at the next moment 2 (n)]e(n)v * (n) and conjugate weight coefficient g(n+1)=g(n)+μ(n)[3p(n)‑e 2 (n)]e(n)v(n); E. Estimating the frequency value at the current moment has a fast estimation speed and small error. When the system is in an unbalanced state, it can still estimate the system frequency quickly and accurately.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a frequency estimation method of a power system, in particular to a frequency estimation method of a three-phase power system. Background technique

[0002] Frequency is one of the important indicators of power quality and an important parameter reflecting the operating state of the power system; it will slowly change in a small range with load fluctuations. In a stable operating state, the output power of the generator is balanced with the system load and loss, and the frequency of the power system is the nominal value. Changes in frequency values ​​can indicate anomalies and disturbances such as harmonics, noise, and unbalanced voltages, so fast and accurate estimates of frequency in power systems are required.

[0003] In a three-phase power system, the traditional frequency estimation method based on single-phase voltage has certain limitations, especially when there is a sudden change in a certain phase. Therefore, in th...

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