CN104090143B - Substation bus bar voltage magnitude instantaneous value measuring method - Google Patents

Abstract

The invention discloses a kind of substation bus bar voltage magnitude instantaneous value measuring method.First the inventive method measures the instantaneous voltage of each sampling instant of substation bus bar voltage, calculate the steady coefficient of the substation bus bar voltage of each sampling instant, calculate the slide coefficient of the substation bus bar voltage of each sampling instant, calculate the substation bus bar electric voltage frequency instantaneous value of each sampling instant, then calculate the amplitude instantaneous value of the substation bus bar voltage of each sampling instant.The certainty of measurement of the inventive method is not by aperiodicity noise impact, data window is short, operand is little, algorithm fast operation, can the most accurately measure the amplitude instantaneous value of the substation bus bar voltage of each sampling instant, provide scientific basis for the real-time peak-frequency regulation of complex large power grid and the reasonable switching of Reactive Power Device.

Description

Substation bus bar voltage magnitude instantaneous value measuring method

Technical field

The present invention relates to power system safety and stability and control technical field, concretely relate to a kind of substation bus bar voltage magnitude instantaneous value measuring method.

Background technology

Realize electrical network each substation bus bar voltage magnitude accurately to measure, can be peak load regulation network frequency modulation and reactive power compensator reasonable switching offer scientific basis.At present power industry mainly utilizes Fourier algorithm to calculate substation bus bar voltage magnitude, and the method hypotheses substation bus bar voltage magnitude keeps stablizing constant within a 20ms cycle, utilizes a cycle data amount extraction substation bus bar voltage magnitude.Due to Fourier algorithm own limitations, desired data window is a cycle, and desired data window is long, and operand is big, and arithmetic speed is slow, and measurement result also can only react all WAVE VOLTAGE AMPLITUDE VALUES situation, it is impossible to measure substation bus bar voltage magnitude in real time.Owing to Fourier algorithm cannot filter aperiodicity noise impact so that certainty of measurement is serious by aperiodicity noise impact, it is impossible to meet the real-time peak-frequency regulation of complex large power grid and the needs of the reasonable switching of Reactive Power Device.

Summary of the invention

It is an object of the invention to the deficiency overcoming prior art to exist, a kind of substation bus bar voltage magnitude instantaneous value measuring method is provided, the certainty of measurement of the method is not by aperiodicity noise impact, data window is short, operand is little, algorithm fast operation, can the most accurately measure the amplitude instantaneous value of the substation bus bar voltage of each sampling instant, provides scientific basis for the real-time peak-frequency regulation of complex large power grid and the reasonable switching of Reactive Power Device.

For completing above-mentioned purpose, the present invention adopts the following technical scheme that

Substation bus bar voltage magnitude instantaneous value measuring method, it is characterised in that include following sequential steps:

(1) instantaneous voltage of each sampling instant of substation bus bar voltage is measured；

(2) the steady coefficient of the substation bus bar voltage of t sampling instant is calculatedWherein, u (t) is the substation bus bar voltage sample value of t sampling instant；(t-k Δ t) is the substation bus bar voltage sample value of t-k Δ t sampling instant to u；(t+k Δ t) is the substation bus bar voltage sample value of t+k Δ t sampling instant to u；Δ t is sampling interval duration；K is data window length, and is positive integer；

(3) slide coefficient of the substation bus bar voltage of t sampling instant is calculatedWherein, u (t) is the substation bus bar voltage sample value of t sampling instant；(t-k Δ t) is the substation bus bar voltage sample value of t-k Δ t sampling instant to u；(t+k Δ t) is the substation bus bar voltage sample value of t+k Δ t sampling instant to u；Δ t is sampling interval duration；K is data window length, and is positive integer；

(4) substation bus bar voltage transient frequency f of calculating t sampling instant:

$f=\frac{1}{2\mathrm{\πk\Δt}}{\cos }^{-1}\left(\frac{\underset{i=-m}{\overset{i=m}{\mathrm{\Σ}}}|\frac{u(t+\mathrm{i\Δt}+\mathrm{k\Δt})}{\sqrt{{\left[u(t+\mathrm{i\Δt}+\mathrm{k\Δt})\right]}^2-{\left[u(t+\mathrm{i\Δt})u(t+\mathrm{i\Δt}+2\mathrm{k\Δt})\right]}^2}}+\frac{u(t+\mathrm{i\Δt}-\mathrm{k\Δt})}{\sqrt{{\left[u(t+\mathrm{i\Δt}-\mathrm{k\Δt})\right]}^2-{\left[u(t+\mathrm{i\Δt})u(t+\mathrm{i\Δt}-2\mathrm{k\Δt})\right]}^2}}|}{\underset{i=-m}{\overset{i=m}{\mathrm{\Σ}}}\frac{2u(t+\mathrm{i\Δt})}{\sqrt{{\left[u(t+\mathrm{i\Δt})\right]}^2-{\left[u(t+\mathrm{i\Δt}+\mathrm{k\Δt})u(t+\mathrm{i\Δt}-\mathrm{k\Δt})\right]}^2}}}\right)$

Wherein, (t+i Δ t) is the substation bus bar voltage sample value of t+i Δ t sampling instant to u；(t+i Δ t-k Δ t) is the substation bus bar voltage sample value of t+i Δ t-k Δ t sampling instant to u；(t+i Δ t+k Δ t) is the substation bus bar voltage sample value of t+i Δ t+k Δ t sampling instant to u；Δ t is sampling interval duration；K is data window length, and is positive integer；(t+i Δ t-2k Δ t) is the substation bus bar voltage sample value of t+i Δ t-2k Δ t sampling instant to u；(t+i Δ t+2k Δ t) is the substation bus bar voltage sample value of t+i Δ t+2k Δ t sampling instant to u；I is integer quotient；M is weighting length；

(5) the substation bus bar voltage magnitude of t sampling instant is calculatedWherein, u (t) is the substation bus bar voltage sample value of t sampling instant；(t-i Δ t) is the substation bus bar voltage sample value of t-i Δ t sampling instant to u；(t+i Δ t) is the substation bus bar voltage sample value of t+i Δ t sampling instant to u；Δ t is sampling interval duration；K is data window length, and is positive integer；I is integer quotient.

The present invention compared with prior art, has a following positive achievement:

The certainty of measurement of the inventive method is not by aperiodicity noise impact, data window is short, operand is little, algorithm fast operation, can the most accurately measure the amplitude instantaneous value of the substation bus bar voltage of each sampling instant, provide scientific basis for the real-time peak-frequency regulation of complex large power grid and the reasonable switching of Reactive Power Device.

Accompanying drawing explanation

Fig. 1 is the two-terminal transmission systems schematic diagram of the application present invention.

Detailed description of the invention

Below according to Figure of description, technical scheme is expressed in further detail.

Fig. 1 is the two-terminal transmission systems schematic diagram of the application present invention.In Fig. 1, PT is substation bus bar voltage transformer.

Substation bus bar voltage magnitude instantaneous value measuring method, specifically includes following steps:

(1) voltage magnitude instantaneous value measurement apparatus measures the instantaneous voltage of each sampling instant of substation bus bar voltage in real time.

(2) the steady coefficient of the substation bus bar voltage of voltage magnitude instantaneous value measurement apparatus calculating t sampling instant

$\sqrt{{\left[u\left(t\right)\right]}^2-{\left[u(t-\mathrm{k\Δt})u(t+\mathrm{k\Δt})\right]}^2}$

Wherein, u (t) is the substation bus bar voltage sample value of t sampling instant；(t-k Δ t) is the substation bus bar voltage sample value of t-k Δ t sampling instant to u；(t+k Δ t) is the substation bus bar voltage sample value of t+k Δ t sampling instant to u；Δ t is sampling interval duration；K is data window length, and is positive integer.

(3) slide coefficient of the substation bus bar voltage of voltage magnitude instantaneous value measurement apparatus calculating t sampling instant

$\frac{u\left(t\right)}{\sqrt{{\left[u\left(t\right)\right]}^2-{\left[u(t-\mathrm{k\Δt})u(t+\mathrm{k\Δt})\right]}^2}}$ Wherein, u (t) is the substation bus bar voltage sample value of t sampling instant；(t-k Δ t) is the substation bus bar voltage sample value of t-k Δ t sampling instant to u；(t+k Δ t) is the substation bus bar voltage sample value of t+k Δ t sampling instant to u；Δ t is sampling interval duration；K is data window length, and is positive integer.

(4) substation bus bar voltage transient frequency f of voltage magnitude instantaneous value measurement apparatus calculating t sampling instant:

$f=\frac{1}{2\mathrm{\πk\Δt}}{\cos }^{-1}\left(\frac{\underset{i=-m}{\overset{i=m}{\mathrm{\Σ}}}|\frac{u(t+\mathrm{i\Δt}+\mathrm{k\Δt})}{\sqrt{{\left[u(t+\mathrm{i\Δt}+\mathrm{k\Δt})\right]}^2-{\left[u(t+\mathrm{i\Δt})u(t+\mathrm{i\Δt}+2\mathrm{k\Δt})\right]}^2}}+\frac{u(t+\mathrm{i\Δt}-\mathrm{k\Δt})}{\sqrt{{\left[u(t+\mathrm{i\Δt}-\mathrm{k\Δt})\right]}^2-{\left[u(t+\mathrm{i\Δt})u(t+\mathrm{i\Δt}-2\mathrm{k\Δt})\right]}^2}}|}{\underset{i=-m}{\overset{i=m}{\mathrm{\Σ}}}\frac{2u(t+\mathrm{i\Δt})}{\sqrt{{\left[u(t+\mathrm{i\Δt})\right]}^2-{\left[u(t+\mathrm{i\Δt}+\mathrm{k\Δt})u(t+\mathrm{i\Δt}-\mathrm{k\Δt})\right]}^2}}}\right)$

Wherein, (t+i Δ t) is the substation bus bar voltage sample value of t+i Δ t sampling instant to u；(t+i Δ t-k Δ t) is the substation bus bar voltage sample value of t+i Δ t-k Δ t sampling instant to u；(t+i Δ t+k Δ t) is the substation bus bar voltage sample value of t+i Δ t+k Δ t sampling instant to u；Δ t is sampling interval duration；K is data window length, and is positive integer；(t+i Δ t-2k Δ t) is the substation bus bar voltage sample value of t+i Δ t-2k Δ t sampling instant to u；(t+i Δ t+2k Δ t) is the substation bus bar voltage sample value of t+i Δ t+2k Δ t sampling instant to u；I is integer quotient；M is weighting length.

(5) voltage magnitude instantaneous value measurement apparatus calculates the substation bus bar voltage magnitude of t sampling instant

$U=\frac{\sqrt{\underset{i=1}{\overset{i=k}{\mathrm{\Σ}}}({\left[u\left(t\right)\right]}^2-{\left[u(t+\mathrm{i\Δt})u(t-\mathrm{i\Δt})\right]}^2)}}{\sqrt{\underset{i=1}{\overset{i=k}{\mathrm{\Σ}}}(1-{\cos }^2\left(2\mathrm{\πfi\Δt}\right))}}$

Wherein, u (t) is the substation bus bar voltage sample value of t sampling instant；(t-i Δ t) is the substation bus bar voltage sample value of t-i Δ t sampling instant to u；(t+i Δ t) is the substation bus bar voltage sample value of t+i Δ t sampling instant to u；Δ t is sampling interval duration；K is data window length, and is positive integer；I is integer quotient.

Voltage magnitude instantaneous value measurement apparatus exports the amplitude instantaneous value result of calculation of the substation bus bar voltage of t sampling instant in real time.

The certainty of measurement of the inventive method is not by aperiodicity noise impact, data window is short, operand is little, algorithm fast operation, can the most accurately measure the amplitude instantaneous value of the substation bus bar voltage of each sampling instant, provide scientific basis for the real-time peak-frequency regulation of complex large power grid and the reasonable switching of Reactive Power Device.

The foregoing is only the preferred embodiment of the present invention; but protection scope of the present invention is not limited thereto; any those familiar with the art in the technical scope that the invention discloses, the change that can readily occur in or replacement, all should contain within protection scope of the present invention.

Claims (1)

1. substation bus bar voltage magnitude instantaneous value measuring method, it is characterised in that include depending on as follows Sequence step:

(1) instantaneous voltage of each sampling instant of substation bus bar voltage is measured；

(2) the steady coefficient of the substation bus bar voltage of t sampling instant is calculatedWherein, u (t) is the substation bus bar voltage sample value of t sampling instant； (t-k Δ t) is the substation bus bar voltage sample value of t-k Δ t sampling instant to u；U is (when t+k Δ t) is t+k Δ t sampling The substation bus bar voltage sample value carved；Δ t is sampling interval duration；K is data window length, and is Positive integer；

(3) slide coefficient of the substation bus bar voltage of t sampling instant is calculatedWherein, u (t) is the substation bus bar voltage sample value of t sampling instant； (t-k Δ t) is the substation bus bar voltage sample value of t-k Δ t sampling instant to u；U is (when t+k Δ t) is t+k Δ t sampling The substation bus bar voltage sample value carved；Δ t is sampling interval duration；K is data window length, and is Positive integer；

(4) substation bus bar voltage transient frequency f of calculating t sampling instant:

$f=\frac{1}{2\mathrm{\π}k\mathrm{\Δ}t}{\cos }^{-1}\left(\frac{\underset{i=-m}{\overset{i=m}{\mathrm{\Σ}}}\left|\frac{u(t+i\mathrm{\Δ}t+k\mathrm{\Δ}t)}{\sqrt{{\[u(t+i\mathrm{\Δ}t+k\mathrm{\Δ}t)\]}^2-{\[u(t+i\mathrm{\Δ}t)u(t+i\mathrm{\Δ}t+2k\mathrm{\Δ}t)\]}^2}}+\frac{u(t+i\mathrm{\Δ}t+k\mathrm{\Δ}t)}{\sqrt{{\[u(t+i\mathrm{\Δ}t-k\mathrm{\Δ}t)\]}^2-{\[u(t+i\mathrm{\Δ}t)u(t+i\mathrm{\Δ}t-2k\mathrm{\Δ}t)\]}^2}}\right|}{\underset{i=-m}{\overset{i=m}{\mathrm{\Σ}}}\frac{2u(t+i\mathrm{\Δ}t)}{\sqrt{{\[u(t+i\mathrm{\Δ}t)\]}^2-{\[u(t+i\mathrm{\Δ}t+k\mathrm{\Δ}t)u(t+i\mathrm{\Δ}t-k\mathrm{\Δ}t)\]}^2}}}\right)$

Wherein, (t+i Δ t) is the substation bus bar voltage sample value of t+i Δ t sampling instant to u；(t+i Δ t-k Δ t) is u The substation bus bar voltage sample value of t+i Δ t-k Δ t sampling instant；U is (when t+i Δ t+k Δ t) is t+i Δ t+k Δ t sampling The substation bus bar voltage sample value carved；Δ t is sampling interval duration；K is data window length, and is Positive integer；(t+i Δ t-2k Δ t) is the substation bus bar voltage sample value of t+i Δ t-2k Δ t sampling instant to u； (t+i Δ t+2k Δ t) is the substation bus bar voltage sample value of t+i Δ t+2k Δ t sampling instant to u；I is integer quotient； M is weighting length；

(5) the substation bus bar voltage magnitude of t sampling instant is calculatedWherein, u (t) is that the substation bus bar voltage of t sampling instant is adopted Sample value；(t-i Δ t) is the substation bus bar voltage sample value of t-i Δ t sampling instant to u；(t+i Δ t) is that t+i Δ t adopts to u The substation bus bar voltage sample value in sample moment；Δ t is sampling interval duration；K is data window length, And be positive integer；I is integer quotient.