CN1702465A - Universal electric energy meter - Google Patents

Abstract

A metering method for electric energy meter comprises following steps: a) collecting load current through current sample circuit and comparing sample circuit of special current formed by (thyristor) witch S and standard resistance group; b) calculating and analyzing by logic circuit or analog integrated circuit after analogue/digital conversion; when non-fundamental component is in tolerance range, electric energy metering is carried out according to traditional metering method; when non-fundamental component is beyond certain regulated standard, the comparing sample circuit of special current is activated; c) making out the electric power with different frequency; d) measuring weighted or calculating the charge; e) giving an alarm or breaking off the electricity when the non-fundamental component is beyond another regulated standard.

Description

Universal electric energy meter

Affiliated technical field

The present invention relates to a kind of metering method of electric energy meter, especially can prevent technical stealing, accurately measure non-simple harmonic quantity electric energy.

Background technology

Present inductance type electric energy meter and the electronic electric energy meter that adopts, its meter can principle based on to loaded work piece voltage, theoretical conclusion when strength of current is simple harmonic quantity.Because circuit generally is not the linear time invariant circuit, and because the widespread use of electron electric power equipment, the operating voltage of load, strength of current function waveform depart from sine wave, and this distortion has ubiquity.The voltage of distortion, strength of current are as non-simple harmonic quantity, and its corresponding electric energy metrical is used induction type electric energy meter or the electronic electric energy meter based on the electric energy metrical Design Pattern of simple harmonic quantity voltage, strength of current, stripped deviation must occur.The degree of deviation increases along with the aggravation of distortion degree, even loses the metering effect.

Make up the current function mathematical model that Fourier series forms based on the current function of load is analyzed, this model comprised possible control voltage technology and when non-linear parameter/the variable of invariable circuit to the influence of current function waveform.

Modern electronic technology especially Analogous Integrated Electronic Circuits and the logical circuit mathematical model that makes the Fourier series of described strength of current function form has measurability.

Below the electronic control voltage technology is done simple declaration to the influence of strength of current function waveform:

If establish power taking source voltage be:

$\tilde{u}\left(x\right)=\sqrt{2}{u}_2{e}^{j(x-\frac{\mathrm{\π}}{2})}$ Promptly $u\left(x\right)$ $\sqrt{2}{u}_2\sin x,x=2\mathrm{\πft}----\left(1\right)$

Usually, the operating voltage of load and control mode thereof are impossible or to be difficult to directly measure, and we can only record the strength of current function of its work and it is analyzed:

$i\left(x\right)\frac{{\mathrm{\&alpha;}}_0}{2}+\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}(a_n\mathrm{connx}+b_n\sin nx)={\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="A20051007931400121.png"\; state="\{\{state\}\}">i</figure-callout>}}_0+\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}\sqrt{2}{i}_n\sin (\mathrm{nx}-{\mathrm{\&psi;}}_u)----\left(2\right)$

Wherein:

${\mathrm{<figure-callout\; id="0"\; label="i"\; filenames="A20051007931400121.png"\; state="\{\{state\}\}">i</figure-callout>}}_0=\frac{{\mathrm{\&alpha;}}_0}{2}=\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(x\right)\mathrm{dx},a_n=\frac{1}{\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(x\right)\mathrm{connxdx},b_n=\frac{1}{\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(x\right)\sin \mathrm{nxdx},$

$i_n=\sqrt{({a_n}^2+{b_n}^2)/2},{\mathrm{\&psi;}}_u=-\mathrm{arctg}\frac{{\&PartialD;}_n}{b_n},n=\mathrm{1,2,3},\&CenterDot;\&CenterDot;\&CenterDot;$

This is one form of strength of current function, is fit to all loads or laod network, and can be obtained by the prior art measurement.

Because the widespread use of electronic circuit, the in check form of the operating voltage of load is varied, and they all can be obtained by this two classes control output of Fig. 1, Fig. 2:

Among Fig. 1:

$=\frac{\sqrt{2}}{\mathrm{\&pi;}}{u}_2\&CenterDot;[\frac{A_0}{2}+(A_1\mathrm{conx}+B_1\sin x)+\mathrm{\&Sigma;}(A_n\mathrm{connx}+B_n\sin \mathrm{nx})----\left(3\right)$

Wherein: A ₀=-cos α ₁+ cos α ₂+ cos β ₁-cos β ₂

$A_1=\frac{-{\sin }^2{\mathrm{\&alpha;}}_1+{\sin }^2{\mathrm{\&alpha;}}_2-{\sin }^2{\mathrm{\&beta;}}_1+{\sin }^2{\mathrm{\&beta;}}_2}{2}$

$B_1=\frac{-2{\mathrm{\&alpha;}}_1+2{\mathrm{\&alpha;}}_2-2{\mathrm{\&beta;}}_1+2{\mathrm{\&beta;}}_2+\sin 2{\mathrm{\&alpha;}}_1-\sin 2{\mathrm{\&alpha;}}_2+\sin 2{\mathrm{\&beta;}}_1-\sin 2{\mathrm{\&beta;}}_2}{4}$

$A_n=\frac{\cos n\mathrm{\&pi;}[\cos (n-1){\mathrm{\&alpha;}}_1-\cos (n-1){\mathrm{\&alpha;}}_2]-\cos (n-1){\mathrm{\&beta;}}_1+\cos (n-1){\mathrm{\&beta;}}_2}{2(n-1)}-\frac{\cos \mathrm{n\&pi;}[\cos (n+1){\mathrm{\&alpha;}}_1-\cos (n+1){\mathrm{\&alpha;}}_2]-\cos (n+1){\mathrm{\&beta;}}_1+\cos (n+1){\mathrm{\&beta;}}_2}{2(n+1)}$

$B_n=\frac{\cos \mathrm{n\&pi;}[\sin (n-1){\mathrm{\&alpha;}}_1-\sin (n-1){\mathrm{\&alpha;}}_2]-\sin (n-1){\mathrm{\&beta;}}_1+\sin (n-1){\mathrm{\&beta;}}_2}{2(n-1)}-\frac{\cos \mathrm{n\&pi;}[\sin (n+1){\mathrm{\&alpha;}}_1-\sin (n+1){\mathrm{\&alpha;}}_2]-\sin (n+1){\mathrm{\&beta;}}_1+\sin (n+1){\mathrm{\&beta;}}_2}{2(n+1)}n=\mathrm{2,3},\&CenterDot;\&CenterDot;\&CenterDot;$

Among Fig. 2:

$=\frac{\sqrt{2}}{\mathrm{\&pi;}}{u}_2\&CenterDot;[\frac{A_0}{2}+(A_1\mathrm{conx}+B_1\sin x)+\mathrm{\&Sigma;}(A_n\mathrm{connx}+B_n\sin \mathrm{nx})]----\left(4\right)$

Wherein: A ₀=2cos α-2cos β-(π 2 α) sin α+(π 2 β) sin β

A ₁＝2sin ²α?2sin ²β

$B_1=\frac{2\mathrm{\&alpha;}+2\mathrm{\&beta;}-\sin 2\mathrm{\&alpha;}-\sin 2\mathrm{\&beta;}}{2}$

$A_n=\frac{1+\cos \mathrm{n\&pi;}}{2}[-\frac{\cos (n-1)\mathrm{\&alpha;}-\cos (n-1)\mathrm{\&beta;}}{n-1}+\frac{\cos (n+1)\mathrm{\&alpha;}-\cos (n+1)\mathrm{\&beta;}}{n+1}+\frac{2\sin \mathrm{\&alpha;}\sin \mathrm{n\&alpha;}-2\sin \mathrm{\&beta;}\sin \mathrm{n\&beta;}}{n}]$

$B_n=\frac{1-\cos \mathrm{n\&pi;}}{2}[-\frac{\sin (n-1)\mathrm{\&alpha;}+\sin (n-1)\mathrm{\&beta;}}{n-1}+\frac{\sin (n+1)\mathrm{\&alpha;}+\sin (n+1)\mathrm{\&beta;}}{n+1}+\frac{2\sin \mathrm{\&alpha;}\cos \mathrm{n\&alpha;}+2\sin \mathrm{\&beta;}\cos \mathrm{n\&beta;}}{n}]n=\mathrm{2,3},\&CenterDot;\&CenterDot;\&CenterDot;$

Above-mentioned two class control technologys represented all technical may, but use modal just wherein some special case.Have only three kinds (special cases of Fig. 1) for what the alternating circuit electric energy metrical was of practical significance:

The unidirectional conducting of diode (control) circuit;

The two-way control circuit of Triac;

The two-way control circuit of two GTO.

For the laod network of a kind of Control of Voltage technology of more than employing, prove that easily they can not be equivalent to a kind of control voltage system and not increase control conducting parameter.Though, can know that from the contrast of (2) and (3), (4) usually, controlled must causing of voltage to measuring contributive first harmonic (first-harmonic) phase shift takes place.This is the root of measurement deviation.

(describe in detail slightly) as can be seen, traditional motor meter and electronic electric energy meter for the energy-dissipation measuring of load all based on following formula:

$P_{\mathrm{\&phi;}}=\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(x\right)\&CenterDot;\sqrt{2}{u}_2\sin \mathrm{xdx}=i_2{u}_2\cos \mathrm{\&phi;}----\left(5\right)$

Wherein the phase differential of i (x) is φ, i (x), $a\left(x\right)=\sqrt{2}{u}_2\sin x$ Be simple harmonic quantity.

Obviously, when i (x) is non-simple harmonic quantity, know: one, have only the dfundamental-harmonic pair electric power measurement that contribution is arranged by formula (2); Two, there is the phase differential because of conducting controlled (being that voltage is controlled) " adding " in first-harmonic.

Also there is the Fourier series that is different from the Control of Voltage generation in invariable circuit when non-linear, but can think that its " equivalence " is in the mode of certain control voltage.For simplified model, establish the linear time invariant that circuit is the controlled voltage working condition, power supply is ideal source and does not contain the facility that suppresses high frequency.We can discuss the error in dipping of aforementioned three kinds of special circuits simply:

1, half-wave-L-R circuit: ginseng Fig. 3, Fig. 6.

$u_f\left(x\right)=\frac{\sqrt{2}}{\mathrm{\&pi;}}{u}_2+\frac{\sqrt{2}}{2}{u}_2\sin x+\frac{\sqrt{2}}{\mathrm{\&pi;}}{u}_2\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}(-\frac{1}{2n-1}+\frac{1}{2n+1})\cos 2\mathrm{nx}$

$i\left(x\right)=\frac{\sqrt{2}}{\mathrm{\&pi;}}\frac{u_2}{R}+\frac{\sqrt{2}}{2}\frac{u_2}{R}\cos \mathrm{\&phi;}\sin (x-\mathrm{\&phi;})-\frac{2\sqrt{2}}{\mathrm{\&pi;}}\frac{u_2}{R}\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}\frac{\cos {\mathrm{\&phi;}}_n}{4n^2-1}\cos (2\mathrm{nx}-{\mathrm{\&phi;}}_n)$

$P_{\mathrm{\&phi;}}=\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(x\right)\&CenterDot;\sqrt{2}{u}_2\sin \mathrm{xdx}=\frac{1}{2}\frac{u_2^2}{R}{\cos }^2\mathrm{\&phi;}----\left(6\right)$

$P_R=\frac{u_2^2}{R}[\frac{2}{{\mathrm{\&pi;}}^2}+\frac{1}{4}{\cos }^2\mathrm{\&phi;}+\frac{4}{{\mathrm{\&pi;}}^2}\underset{n-1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{\left(\frac{\cos {\mathrm{\&phi;}}_n}{4n^2-1}\right)}^2----\left(7\right)$

Wherein: $\mathrm{\&phi;}=\mathrm{arctg}\frac{\mathrm{\&omega;L}}{R},{\mathrm{\&phi;}}_n=\mathrm{arctg}\frac{2\mathrm{n\&omega;L}}{R},n=\mathrm{1,2,3},\&CenterDot;\&CenterDot;\&CenterDot;$

Obviously, φ → 0 o'clock, $P_{\mathrm{\&phi;}}\&RightArrow;P_R\&RightArrow;\frac{1}{2}\frac{u_2^2}{R};$ Measure bias free in theory.

$\mathrm{\&phi;}\&RightArrow;\frac{\mathrm{\&pi;}}{2}$ The time, $P_R\&RightArrow;\frac{2}{{\mathrm{\&pi;}}^2}\frac{u_2^2}{R},P_R\&RightArrow;0;$ Do not measure electric energy.

$\left|\cos \mathrm{\&phi;}\right|\&le;\frac{2\sqrt{2}}{\mathrm{\&pi;}}$ The time, P _R＞P _φ, stripped deviation promptly appears.

2, Triac-L-R circuit: ginseng Fig. 4, Fig. 7.

$u_f\left(x\right)=\frac{\sqrt{2}}{\mathrm{\&pi;}}{u}_2\frac{{\sin }^2\mathrm{\&alpha;}}{\sin \mathrm{\&theta;}}\sin (x-\mathrm{\&theta;})+\frac{\sqrt{2}}{\mathrm{\&pi;}}{u}_2\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}\frac{\frac{\sin 2\mathrm{n\&alpha;}}{2n}-\frac{\sin 2(n+1)\mathrm{\&alpha;}}{2(n+1)}}{\sin {\mathrm{\&theta;}}_n}\cos [(2n+1)x+{\mathrm{\&theta;}}_n]$

$i\left(x\right)=\frac{\sqrt{2}}{\mathrm{\&pi;}}\frac{u_2}{R}\frac{{\sin }^2\mathrm{\&alpha;}}{\sin \mathrm{\&theta;}}\cos \mathrm{\&phi;}\sin (x-\mathrm{\&theta;}-\mathrm{\&phi;})+\frac{\sqrt{2}}{\mathrm{\&pi;}}\frac{u_2}{R}\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}\frac{\frac{\sin 2\mathrm{n\&alpha;}}{2n}-\frac{\sin 2(n+1)\mathrm{\&alpha;}}{2(n+1)}}{\sin {\mathrm{\&theta;}}_n}\cos {\mathrm{\&phi;}}_n\cos [(2n+1)x-{\mathrm{\&phi;}}_n+{\mathrm{\&theta;}}_n]$

$P_{\mathrm{\&phi;}}=\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(x\right)\&CenterDot;\sqrt{2}{u}_2\sin \mathrm{xdx}=\frac{1}{\mathrm{\&pi;}}\frac{u_2^2}{R}\frac{{\sin }^2\mathrm{\&alpha;}}{\sin \mathrm{\&theta;}}\cos \mathrm{\&phi;}\cos (\mathrm{\&theta;}+\mathrm{\&phi;})----\left(8\right)$

$P_R=\frac{1}{{\mathrm{\&pi;}}^2}\frac{u_2^2}{R}{\left(\frac{{\sin }^2\mathrm{\&alpha;}\cos \mathrm{\&phi;}}{\sin \mathrm{\&theta;}}\right)}^2+\frac{1}{{\mathrm{\&pi;}}^2}\frac{u_2^2}{R}\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{\left[\frac{\frac{\sin 2\mathrm{n\&alpha;}}{2n}-\frac{\sin 2(n+1)\mathrm{\&alpha;}}{2(n+1)}}{\sin {\mathrm{\&theta;}}_n}\cos {\mathrm{\&phi;}}_n\right]}^2----\left(9\right)$

Wherein: $\mathrm{\&phi;}=\mathrm{arctg}\frac{\mathrm{\&omega;L}}{R},{\mathrm{\&phi;}}_n=\mathrm{arctg}\frac{(2n+1)\mathrm{\&omega;L}}{R},$

$\mathrm{\&theta;}=\mathrm{arctg}\frac{2{\sin }^2\mathrm{\&alpha;}}{2\mathrm{\&pi;}-2\mathrm{\&alpha;}+\sin 2\mathrm{\&alpha;}},{\mathrm{\&theta;}}_n=\mathrm{arctg}\frac{\frac{1-\cos 2\mathrm{n\&alpha;}}{2n}-\frac{1-\cos 2(n+1)\mathrm{\&alpha;}}{2(n+1)}}{\frac{\sin 2\mathrm{n\&alpha;}}{2n}-\frac{\sin 2(n+1)\mathrm{\&alpha;}}{2(n+1)}},n=\mathrm{1,2,3},\&CenterDot;\&CenterDot;\&CenterDot;$

Obviously, during α → π-φ, $P_{\mathrm{\&phi;}}\&RightArrow;\frac{1}{\mathrm{\&pi;}}\frac{u_2^2}{R}(\mathrm{\&phi;}\cos \mathrm{\&phi;}-\sin \mathrm{\&phi;})\cos \mathrm{\&phi;}<0;$ Be equivalent to the ammeter reversing.

When α → pi/2, φ → pi/2, $P_{\mathrm{\&phi;}}\&RightArrow;-\frac{1}{\mathrm{\&pi;}}\frac{u_2^2}{\mathrm{\&omega;L}},P_R\&RightArrow;0;$ Be equivalent to the ammeter reversing.

α→π/2， $\mathrm{\&phi;}\&RightArrow;\mathrm{arctg}\frac{\mathrm{\&pi;}}{2}$ The time, $P_{\mathrm{\&phi;}}\&RightArrow;0,P_R\&RightArrow;\frac{1}{{\mathrm{\&pi;}}^2}\frac{u_2^2}{R},$ Being equivalent to the electricity consumption ammeter does not change.

3,2GTO-C-R circuit: ginseng Fig. 5, Fig. 8.

$u_f\left(x\right)=\frac{\sqrt{2}}{\mathrm{\&pi;}}{u}_2\frac{{\sin }^2\mathrm{\&alpha;}}{\sin \mathrm{\&theta;}}\sin (x+\mathrm{\&theta;})+\frac{\sqrt{2}}{\mathrm{\&pi;}}{u}_2\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{C}_n\sin [(2n+1)x+{\mathrm{\&theta;}}_n]$

$i\left(x\right)=\frac{\sqrt{2}}{\mathrm{\&pi;}}\frac{u_2}{R}\frac{{\sin }^2\mathrm{\&alpha;}}{\sin \mathrm{\&theta;}}\cos \mathrm{\&phi;}\sin (x+\mathrm{\&theta;}+\mathrm{\&phi;})+\frac{\sqrt{2}}{\mathrm{\&pi;}}\frac{u_2}{R}\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{C}_n\cos {\mathrm{\&phi;}}_n\sin [(2n+1)x+{\mathrm{\&theta;}}_n+{\mathrm{\&phi;}}_n]$

$P_{\mathrm{\&phi;}}=\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(x\right)\&CenterDot;\sqrt{2}{u}_2\sin \mathrm{xdx}=\frac{1}{\mathrm{\&pi;}}\frac{u_2^2}{R}\frac{{\sin }^2\mathrm{\&alpha;}}{\sin \mathrm{\&theta;}}\cos \mathrm{\&phi;}\cos (\mathrm{\&theta;}+\mathrm{\&phi;})----\left(10\right)$

$P_R=\frac{1}{{\mathrm{\&pi;}}^2}\frac{u_2^2}{R}{\left(\frac{{\sin }^2\mathrm{\&alpha;}}{\sin \mathrm{\&theta;}}\cos \mathrm{\&phi;}\right)}^2+\frac{1}{{\mathrm{\&pi;}}^2}\frac{u_2^2}{R}\underset{n=1}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{C}_n^2{\cos }^2{\mathrm{\&phi;}}_n----\left(11\right)$

Wherein: $\mathrm{\&phi;}=\mathrm{arctg}\frac{1}{\mathrm{\&omega;CR}},{\mathrm{\&phi;}}_n=\mathrm{arctg}\frac{1}{(2n+1)\mathrm{\&omega;CR}},$

$\mathrm{\&theta;}=\mathrm{arctg}\frac{2{\sin }^2\mathrm{\&alpha;}}{2\mathrm{\&alpha;}-\sin 2\mathrm{\&alpha;}},{\mathrm{\&theta;}}_n=\mathrm{arctg}\frac{\frac{1-\cos 2\mathrm{n\&alpha;}}{2n}-\frac{1-\cos 2(n+1)\mathrm{\&alpha;}}{2(n+1)}}{\frac{\sin 2\mathrm{n\&alpha;}}{2n}-\frac{\sin 2(n+1)\mathrm{\&alpha;}}{2(n+1)}}$

$C_n=\sqrt{{[\frac{1-\cos 2\mathrm{n\&alpha;}}{2n}-\frac{1-\cos 2(n+1)\mathrm{\&alpha;}}{2(n+1)}]}^2+{[\frac{\sin 2\mathrm{\&alpha;}}{2n}-\frac{\sin 2(n+1)\mathrm{\&alpha;}}{2(n+1)}]}^2},n=1,2,3,\&CenterDot;\&CenterDot;\&CenterDot;$

Obviously, during α → π-φ, $P_{\mathrm{\&phi;}}\&RightArrow;\frac{1}{\mathrm{\&pi;}}\frac{u_2^2}{R}[(\mathrm{\&pi;}-\mathrm{\&phi;})\cos \mathrm{\&phi;}-\sin \mathrm{\&phi;}]\cos \mathrm{\&phi;}<0;$

When α → pi/2, φ → pi/2, $P_{\mathrm{\&phi;}}\&RightArrow;-\frac{1}{\mathrm{\&pi;}}\mathrm{\&omega;}{\mathrm{Cu}}_2,P_R\&RightArrow;0;$

α→π/2， $\mathrm{\&phi;}\&RightArrow;\mathrm{arctg}\frac{\mathrm{\&pi;}}{2}$ The time, P _φ→ 0, $P_{\mathrm{\&phi;}}\&RightArrow;\frac{1}{{\mathrm{\&pi;}}^2}\frac{u_2^2}{R}.$

Can find from above-mentioned simple discussion, in side circuit, being combined in of some form of R, L, C makes under the controlled voltage that multi-form deviation appears in metering, wherein, comprises that electric energy meter measures (normal controlled electricity consumption) less, do not measure even negative metering (technical stealing).

Summary of the invention

In order to overcome the shortcoming that induction type electric energy meter and electronic electric energy meter can not accurately measure the electric energy of non-simple harmonic quantity correspondence, reduce the electric energy metrical loss, prevent that stealing electricity phenomenon from taking place, and the invention provides a kind of electric power meter | method.

The technical solution adopted for the present invention to solve the technical problems is: gather load current by current sampling circuit and specific current contrast sample circuit, after mould/number conversion by logical circuit or | and Analogous Integrated Electronic Circuits carries out operational analysis, asks for strength of current i (x) and operating voltage u _f(x) flip-flop, first-harmonic composition and the 3rd, the electric energy (or electricity charge) that consumes of (and weighting) First Astronautic Research Institute for Measurement and Test is respectively stored and is shown its value.

After flip-flop and higher hamonic wave surpass certain proportion in analyzing current sampling circuit, specific current contrast sample circuit is accepted instruction, automatically in load, insert the measuring resistance (make the electric current of surveying than current sampling circuit institute measured value with about 5%) of certain value, according to the reactance of load under each frequency of comparative determination, extrapolate the magnitude of voltage of each harmonic.

For the non-simple harmonic quantity electric energy that surpasses a certain required standard that detects, weighting is chargeed; For the non-simple harmonic quantity electric energy that surpasses another required standard that detects, in advance with warning, outage.

Strength of current i that the metering of the electric energy of each harmonic wave is obtained according to two sample circuits (x) and operating voltage u _f(x) Fourier series, by logical circuit or | and Analogous Integrated Electronic Circuits carries out computing.

The invention has the beneficial effects as follows and to measure the load power consumption exactly, especially significant at electron electric power equipment non-simple harmonic quantity electric energy metrical extensively suitable, strength of current/function of voltage waveform substantial deviation sine wave, promptly can reduce error in dipping, rationally share the electricity charge, prevent technical stealing, improve power grid quality and economic benefit.

Description of drawings

Fig. 1 adopts α ₁, α ₂, β ₁, β ₂The Control of Voltage output waveform of four conduction angle parameters.

Fig. 2 adopts α, the Control of Voltage output waveform at β slicing peak.

Fig. 1, Fig. 2 have comprised existing all possible Control of Voltage output waveforms.

Fig. 3 is half-wave-L-R circuit diagram.

Fig. 4 is the L-R circuit diagram of bidirectional thyristor control output.

Fig. 5 can turn-off the L-R circuit diagram of into proposing the two-way control output of thyristor.

Fig. 6,7,8 is respectively half-wave, two-way controlled, the two-way voltage waveform that turn-offs control output.

Fig. 9 is the basic circuit diagram of first embodiment of the present invention.

Figure 10 is the basic circuit diagram of second embodiment of the present invention.

Figure 11 is a specific current contrast sample circuit synoptic diagram of the present invention.

Embodiment

In first embodiment, at first, after mould/number conversion, analyze by the current sampling circuit sampling as Fig. 9:

(suppose 90% in the example) in allowed limits when non-first-harmonic composition in the electric current, carry out electric energy metrical according to traditional metering method.

Non-first-harmonic composition surpasses a certain required standard in electric current, send instruction, start specific current contrast sample circuit and gather load current, after mould/number conversion, analyze, obtain the magnitude of voltage and the corresponding electric power of direct current, first-harmonic, frequency multiplication and frequency tripling, and be weighted metering or charging according to corresponding standard.

Non-first-harmonic composition surpasses another required standard in electric current, in advance with warning, outage.

The electric energy of metering or electricity charge storage back output, demonstration.

Electric energy metrical is got several subharmonic, the corresponding techniques standard should be formulated as required by correlation technique superintendent office, and this technical manual has perhaps been arranged.

Figure 10 is second embodiment, and different with Fig. 9 is mould/number and D/A switch and computing, logical circuit are different.

Specific current contrast sample circuit shown in Figure 11 mainly is made up of (thyristor) switch S, measuring resistance group.When accept the instruction back, S is transformed into the measuring resistance group, resistance changes high by low, remains on to make strength of current decline about 5%.Like this, can know strength of current, the magnitude of voltage of every kind of frequency component on measuring resistance, and then infer the power of resistance value, magnitude of voltage and the dissipation of load under each secondary frequencies.

In the above-described embodiments, current sample by mimic channel or | and digital circuit carries out computing.Detailed application circuit is not given unnecessary details again.

Can get following parameter after the sampling computing of current sampling circuit:

$i_0=\frac{{\mathrm{\&alpha;}}_0}{2}=\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(x\right)\mathrm{dx}$

$a_n=\frac{1}{\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(x\right)\mathrm{connxdx}$

$b_n=\frac{1}{\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}i\left(\mathrm{\&chi;}\right)\sin \mathrm{n\&chi;d\&chi;}$

$i_n=\sqrt{({a_n}^2+{b_n}^2)/2}$

${\mathrm{\&psi;}}_n=-\mathrm{arctg}\frac{a_n}{b_n},n=\mathrm{1,2,3},\&CenterDot;\&CenterDot;\&CenterDot;$

Can get following parameter after the sampling computing of specific current contrast sample circuit:

${\mathrm{<figure-callout\; id="0"\; label="u"\; filenames="A20051007931400121.png"\; state="\{\{state\}\}">u</figure-callout>}}_0=\frac{A_0}{2}=\frac{1}{2\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}I\left(x\right)\mathrm{dx}$

$A_n=\frac{1}{\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}I\left(x\right)\mathrm{connxdx}$

$B_n=\frac{1}{\mathrm{\&pi;}}{\&Integral;}_{-\mathrm{\&pi;}}^{\mathrm{\&pi;}}I\left(x\right)\sin \mathrm{nxdx}$

$u_n=\sqrt{({a_n}^2+{b_n}^2)/2}$

${\mathrm{\&psi;}}_n=-\mathrm{arctg}\frac{A_n}{B_n},n=\mathrm{1,2,3},\&CenterDot;\&CenterDot;\&CenterDot;$

The power consumption of specific current contrast sample circuit is more, does not under normal circumstances start.Have only when non-first-harmonic composition is lower than the required standard value in the electric current, just start specific current contrast sample circuit and carry out timing, intermittent sampling according to different situations.The general effective value that only needs Analogous Integrated Electronic Circuits or logical circuit computing to ask for the flip-flop of strength of current and operating voltage, first-harmonic, frequency multiplication, frequency tripling gets final product.

The principle of work of specific current contrast sample circuit:

Strength of current under arbitrary frequency

For measuring resistance r, have:

u _n＝i _nr＝I _nZ _n n＝1，2，3，…

Because the value of r is little to load effect, in certain short period, can think that the condition of measuring does not change, and measures the strength of current i under the n secondary frequencies repeatedly _n, I _nValue through the contrast computing, is obtained the effective value of its voltage, and then is calculated the electric energy of this subharmonic.Last power consumption or the electricity charge total according to the relevant specification weighted calculation, and realize other storage, control, output function simultaneously.

Z _nBe the load reactance under the n secondary frequencies.

Claims (4)

1 one kinds of electric energy meters, mainly contrast sample circuit A/D converter Analogous Integrated Electronic Circuits by the current sampling circuit specific current or/and logical circuit D/A storage output control gear etc. formed, it is characterized in that: gather load current by current sampling circuit and specific current contrast sample circuit, after mould/number conversion by logical circuit or | and Analogous Integrated Electronic Circuits is carried out operational analysis:

Non-first-harmonic composition carries out electric energy metrical according to traditional metering method in allowed limits in electric current.

Non-first-harmonic composition surpasses a certain required standard in electric current, starts specific current contrast sample circuit sampling after mould/number conversion, analysis, obtains the electric power of each frequency, is weighted metering or charges.

Non-first-harmonic composition surpasses another required standard in electric current, in advance with warning, outage.

2 electric energy meters according to claim 1 is characterized in that: the specific current contrast sample circuit measuring resistance group of having connected in load circuit generally reaches with the resistance of measuring its strength of current measuring resistance group and makes its strength of current value descend about 5% and be enough to accurately contrast metering, analyze.

3 electric energy meters according to claim 1 is characterized in that: the sampling to specific current contrast sample circuit is analyzed, and asks for the load equivalent reactance (or resistance) under different frequencies such as direct current first-harmonic frequency multiplication and frequency tripling.

4 electric energy meters according to claim 1 is characterized in that: the sample mode of specific current contrast sample circuit is regularly, intermittent sampling.

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