CN104090228A - Analog circuit fuzzy group identification method - Google Patents

Abstract

The invention discloses an analog circuit fuzzy group identification method. The general characteristic of the fault voltage of an analog circuit element is derived through a theory, wherein the characteristic is that a real part and an imaginary part meet an equation of a circle. According to the characteristic, the fuzzy group identification method is provided. The method includes the steps that fault-free simulation is conducted on each fault source firstly, so that a fault-free voltage value of each measuring point is obtained; simulation is conducted under two fault conditions, so that two fault voltage values are obtained; according to the three voltage values, an equation set of the circle is solved, so that circle characteristic parameters are obtained; the circle characteristic parameters corresponding to the fault sources are compared and the fault sources with the three same parameters are classified into a fuzzy group. According to the method, a transmission function is not needed, an achieving method is simple, a fuzzy group identification result is not related to a testing method, and the accuracy is the same as that of a transmission function and symbol analysis method.

Description

The recognition methods of a kind of mimic channel ambiguity group

Technical field

The invention belongs to Analog Circuit Fault Diagnosis Technology field, more specifically say, relate to the recognition methods of a kind of mimic channel ambiguity group.

Background technology

Ambiguity group is defined as a set of pieces, there is no unique solution for the measured equation of tested mimic channel.Be exactly generally that this set of pieces can produce identical output.The ambiguity group information of determining mimic channel is the top priority of carrying out analog circuit test design and fault diagnosis.Ambiguity group information is determined by tested mimic channel characteristic, irrelevant with method of testing.Ambiguity group recognition methods at present mainly contains two kinds.One is by measured equation group (transition function of different measuring points) is carried out to QR decomposition, judges ambiguity group information.These class methods are subject to the impact of QR resolution error, become large with circuit scale, and its precision sharply declines.Another kind method is that measured equation group is carried out to Symbolic Representation, has avoided QR resolution error.Its basic thought is the transition function system of equations on all measuring points of model.

Equation in the transition function system of equations of mimic channel can be expressed as:

$h_l(p,s)=\frac{N_l(p,s)}{D(p,s)}=\frac{\underset{i=0}{\overset{n_l}{\mathrm{\Σ}}}\frac{a_i^{\left(l\right)}\left(p\right)*s^i}{b_m\left(p\right)}}{s^m+\underset{j=0}{\overset{m-1}{\mathrm{\Σ}}}\frac{b_j\left(p\right)}{b_m\left(p\right)}*s^j},l=\mathrm{1,2},\·\·\·,k---\left(1\right)$

Wherein, p=[p ₁, p ₂..., p _r] ^trepresent incipient fault source parameter vector, subscript T represents transposition, and k represents equation number, i.e. measuring point number, and l represents measuring point sequence number, and s represents complex frequency, and m represents maximum order, n _lrepresent the item number of molecule; b _j(p), b _m(p) coefficient of expression equation, is the polynomial expression of p.

For the each equation in system of equations (1), respectively to each source of trouble parameter p _r∈ p carries out differentiate.Obtain suc as formula the matrix B shown in (2).

The measurability index of circuit-under-test equates with the order of matrix B, and it is independent of complex frequency s.Testability matrix B can represent by following form.

Wherein and B _j, (j=1,2 ..., m-1), be the coefficient of the diagnosis equation that calculated in formula (1).The Jacobi matrix of this system is equal to matrix B, if the order of B equals the number of unknown parameter, the value of these components and parts can be determined uniquely.If testability, the order of matrix B is less than the quantity of unknown parameter R, and not all fault can be distinguished, and rank of matrix has just reflected ambiguity group information.

It is easily a lot of that the calculating of Symbolic Analysis Method is wanted compared to transport function, but in the denominator of measured equation, the coefficient of complex frequency s must equal 1, and still can not break away from the dependence to transition function.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art, the recognition methods of a kind of mimic channel ambiguity group is provided, the method is without transition function, the measuring point voltage obtaining by emulation can obtain the equation of a circle of each element in mimic channel, can identify ambiguity group by the characteristic parameter that compares equation of a circle.

For achieving the above object, the present invention carries out theory to the voltage of element in tested mimic channel and derives, reach a conclusion: for each source of trouble, under any source of trouble parameter, real part and the imaginary part of the voltage producing at same measuring point all meet same equation of a circle, by equation of a circle characteristic parameter corresponding to more each source of trouble, can whether can be distinguished in failure judgement source.Propose mimic channel ambiguity group of the present invention recognition methods according to this conclusion, specifically comprise the following steps:

S1: mimic channel is carried out to non-fault emulation, obtain the non-fault voltage of measuring point t j represents imaginary unit;

S2: make d=1;

S3: by the parameter x of d source of trouble element _dchange to x _d1and x _d2carry out respectively emulation, obtain the false voltage of measuring point t, be designated as respectively ${\stackrel{\·}{U}}_1=U_{1r}+U_{1j}j,{\stackrel{\·}{U}}_2=U_{2r}+U_{2j}j;$

S4: if $\frac{U_{1j}-U_{\mathrm{oj}}}{U_{1r}-U_{\mathrm{or}}}=\frac{U_{2j}-U_{\mathrm{oj}}}{U_{2r}-U_{\mathrm{or}}},$ $K_d=\frac{U_{1j}-U_{\mathrm{oj}}}{U_{1r}-U_{\mathrm{or}}},$ Order circle characteristic parameter wd=1, v _d=-K _d, r _d=0, obtain circle characteristic parameter w otherwise solve following system of equations _d, v _d, r _d:

$\left\{\begin{array}{c}{(U_{\mathrm{or}}-w_d)}^2+{(U_{\mathrm{oj}}-v_d)}^2={r_d}^2\\ {(U_{1r}-w_d)}^2+{(U_{1j}-v_d)}^2={r_d}^2\\ {(U_{2r}-w_d)}^2+{(U_{2j}-v_d)}^2={r_d}^2\end{array}\right.$

S5: judge whether d=N _f, N _frepresent source of trouble quantity, if so, enter step S6, otherwise make d=d+1, return to step S3;

S6: the round characteristic parameter that more each source of trouble is corresponding, by three parameters all the identical source of trouble be classified as an ambiguity group.

Mimic channel ambiguity group of the present invention recognition methods, derive by theory the general characteristic that analog circuit element false voltage has: real part imaginary part meets equation of a circle, according to this characteristic, ambiguity group recognition methods is proposed: for each source of trouble, first carry out non-fault emulation and obtain the non-fault magnitude of voltage of measuring point, under two fault conditions, carry out again emulation and obtain two false voltage values, solve equation of a circle group according to three magnitudes of voltage and obtain circle characteristic parameter, the round characteristic parameter that more each source of trouble is corresponding, by three parameters all the identical source of trouble be classified as an ambiguity group.The present invention is without transition function, and its implementation is simple, and ambiguity group recognition result and method of testing are irrelevant, and precision is identical with transition function and Symbolic Analysis Method.

Brief description of the drawings

Fig. 1 is mimic channel figure;

Fig. 2 is the equivalent circuit diagram of mimic channel shown in Fig. 1;

Fig. 3 is the voltage source effect schematic diagram of mimic channel shown in Fig. 1;

Fig. 4 is the source of trouble effect schematic diagram of mimic channel shown in Fig. 1;

Fig. 5 is the embodiment process flow diagram of mimic channel ambiguity group of the present invention recognition methods;

Fig. 6 is mimic channel schematic diagram in embodiment;

Fig. 7 draws according to equation of a circle characteristic parameter in table 1 the each source of trouble characteristic of correspondence circle obtaining.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described, so that those skilled in the art understands the present invention better.Requiring particular attention is that, in the following description, in the time that perhaps the detailed description of known function and design can desalinate main contents of the present invention, these are described in here and will be left in the basket.

For technology contents of the present invention and inventive point are described better, first theoretical derivation of the present invention is described.

Fig. 1 is mimic channel figure.As shown in Figure 1, mimic channel N is by independent voltage source excitation. represent the voltage phasor obtaining on selected measuring point, x is passive element.According to Substitution Theoren, x can be replaced by the independent voltage source identical with its terminal voltage, obtains equivalent electrical circuit.Fig. 2 is the equivalent circuit diagram of mimic channel shown in Fig. 1.According to Thevenin's theorem, have:

${\stackrel{\·}{U}}_x={\stackrel{\·}{U}}_{\mathrm{oc}}\frac{Z_x}{Z_0+Z_x}---\left(4\right)$

Wherein, a and b port open voltage phasor in Fig. 2; Z ₀the Dai Weining resistance value between a and b, Z _xfor the resistance value of element x.According to Thevenin's theorem, and Z ₀value be independent of Z _x, and only determined by non-fault component parameters and network structure.In Fig. 2 in Fig. 1 equate.In Fig. 2, mimic channel N by with common excitation.According to superposition principle, the voltage in Fig. 2 equal with the algebraic sum of output voltage when independent role.Fig. 3 is the voltage source effect schematic diagram of mimic channel shown in Fig. 1.Fig. 4 is the source of trouble effect schematic diagram of mimic channel shown in Fig. 1.As shown in Figure 3 and Figure 4, voltage source and the source of trouble when independent role, output voltage is used respectively with represent, have according to superposition principle:

${\stackrel{\·}{U}}_o={\stackrel{\·}{U}}_o\′+{\stackrel{\·}{U}}_o\′\′={\stackrel{\·}{U}}_{s}H\′\left(\mathrm{j\ω}\right)+{\stackrel{\·}{U}}_{x}H\′\′\left(\mathrm{j\ω}\right)---\left(5\right)$

" (j ω) is respectively power port and the element x place port transport function to output port, and irrelevant with the parameter value of element x for wherein, H ' (j ω) and H.By formula (4) substitution formula (5), cancellation obtain output voltage to source of trouble resistance value Z through abbreviation _xfuntcional relationship as follows:

${\stackrel{\·}{U}}_o={\stackrel{\·}{U}}_{s}H\′\left(\mathrm{j\ω}\right)+{\stackrel{\·}{U}}_{\mathrm{oc}}\frac{Z_x}{Z_0+Z_x}H\′\′\left(\mathrm{j\ω}\right)---\left(6\right)$

Can obtain Dai Weining equiva lent impedance Z from above formula ₀with Z _xrelation as follows:

$\begin{array}{c}\frac{Z_0}{Z_x}=\frac{{\stackrel{\·}{U}}_{\mathrm{oc}}H\′\′\left(\mathrm{j\ω}\right)-({\stackrel{\·}{U}}_o-{\stackrel{\·}{U}}_{s}H\′\left(\mathrm{j\ω}\right))}{{\stackrel{\·}{U}}_o-{\stackrel{\·}{U}}_{s}H\′\left(\mathrm{j\ω}\right)}\\ =\frac{{\stackrel{\·}{U}}_{\mathrm{oc}}H\′\′\left(\mathrm{j\ω}\right)}{{\stackrel{\·}{U}}_{\mathrm{os}}}-1\\ {\stackrel{\·}{U}}_{\mathrm{os}}={\stackrel{\·}{U}}_o-{\stackrel{\·}{U}}_{s}H\′\left(\mathrm{j\ω}\right)\end{array}---\left(7\right)$

Without loss of generality, each phasor is represented with rectangular coordinate:

$\left\{\begin{array}{c}{Z}_0=R_0+j{X}_0\\ {\stackrel{\·}{U}}_{\mathrm{os}}=U_{\mathrm{osr}}+j{U}_{\mathrm{osj}}\\ {\stackrel{\·}{U}}_{\mathrm{oc}}H\′\′\left(\mathrm{j\ω}\right)=\mathrm{\α}+\mathrm{j\β}\end{array}\right.---\left(8\right)$

Wherein, j is imaginary unit.Because h ' (j ω), h " (j ω) and Z ₀all be independent of Z _xso, R ₀, X ₀, α and β be also independent of Z _x.(8) formula substitution (7) formula is obtained:

$\frac{R_0+j{X}_0}{Z_x}=\frac{{\mathrm{\αU}}_{\mathrm{osr}}+\mathrm{\β}{U}_{\mathrm{osj}}}{U_{\mathrm{osr}}^2+U_{\mathrm{osj}}^2}-1+j\frac{\mathrm{\β}{U}_{\mathrm{osr}}-\mathrm{\α}{U}_{\mathrm{osj}}}{U_{\mathrm{osr}}^2+U_{\mathrm{osj}}^2}---\left(9\right)$

Suppose that element x is resistance, note Z _x=R _x, equate according to formula (9) both sides real part and imaginary part, obtain:

$\left\{\begin{array}{c}\frac{R_0}{R_x}=\frac{\mathrm{\α}{U}_{\mathrm{osr}}+\mathrm{\β}{U}_{\mathrm{osj}}}{U_{\mathrm{osr}}^2+U_{\mathrm{osj}}^2}-1\\ \frac{X_0}{R_x}=\frac{\mathrm{\β}{U}_{\mathrm{osr}}-\mathrm{\α}{U}_{\mathrm{osj}}}{U_{\mathrm{osr}}^2+U_{\mathrm{osj}}^2}\end{array}\right.---\left(10\right)$

The R that disappears of two equations in simultaneous (10) _x, obtain as shown in the formula formula:

$\frac{R_0}{X_0}\frac{\mathrm{\β}{U}_{\mathrm{osr}}-\mathrm{\α}{U}_{\mathrm{osj}}}{U_{\mathrm{osr}}^2+U_{\mathrm{osj}}^2}-\frac{\mathrm{\α}{U}_{\mathrm{osr}}+\mathrm{\β}{U}_{\mathrm{osj}}}{U_{\mathrm{osr}}^2+U_{\mathrm{osj}}^2}+1=0---\left(11\right)$

The denominator that disappears in (11) formula, be not difficult to release:

$\begin{array}{c}\frac{R_0}{X_0}(\mathrm{\β}{U}_{\mathrm{osr}}-\mathrm{\α}{U}_{\mathrm{osj}})-(\mathrm{\α}{U}_{\mathrm{osr}}+\mathrm{\β}{U}_{\mathrm{osj}})+U_{\mathrm{osr}}^2+U_{\mathrm{osj}}^2=0\\ \⇒U_{\mathrm{osr}}^2+(\frac{R_0}{X_0}\mathrm{\β}-\mathrm{\α})\mathrm{\β}{U}_{\mathrm{osr}}+U_{\mathrm{osj}}^2-(\frac{R_0}{X_0}\mathrm{\α}+\mathrm{\β})U_{\mathrm{osj}}=0\\ \⇒{[U_{\mathrm{osr}}-\frac{1}{2}(\mathrm{\α}-\frac{R_0}{X_0}\mathrm{\β})]}^2+{[U_{\mathrm{osj}}-\frac{1}{2}(\mathrm{\β}+\frac{R_0}{X_0}\mathrm{\α})]}^2=\frac{1}{4}[{(\mathrm{\α}-\frac{R_0}{X_0}\mathrm{\β})}^2+{(\mathrm{\β}+\frac{R_0}{X_0}\mathrm{\α})}^2]\end{array}---\left(12\right)$

Due to ${\stackrel{\·}{U}}_{\mathrm{os}}={\stackrel{\·}{U}}_o-{\stackrel{\·}{U}}_{s}H\′\left(\mathrm{j\ω}\right),$ Suppose that Dai Weining equivalent voltage is ${\stackrel{\·}{U}}_o=U_{\mathrm{or}}+j{U}_{\mathrm{oj}},$ The output voltage of power generation is output voltage real part and the imaginary part of faulty circuit can represent as follows:

$\left\{\begin{array}{c}{U}_{\mathrm{osr}}=U_{\mathrm{or}}-{U^{\′}}_{\mathrm{or}}\\ U_{\mathrm{osj}}=U_{\mathrm{oj}}-{U^{\′}}_{\mathrm{oj}}\end{array}\right.---\left(13\right)$

By formula (13) substitution formula (12), obtain following formula:

$\begin{array}{c}{[U_{\mathrm{or}}-{U^{\′}}_{\mathrm{or}}-\frac{1}{2}(\mathrm{\α}-\frac{R_0}{X_0}\mathrm{\β})]}^2+{[U_{\mathrm{oj}}-{U^{\′}}_{\mathrm{oj}}-\frac{1}{2}(\mathrm{\β}+\frac{R_0}{X_0}\mathrm{\α})]}^2\\ =\frac{1}{4}[{(\mathrm{\α}-\frac{R_0}{X_0}\mathrm{\β})}^2+{(\mathrm{\β}+\frac{R_0}{X_0}\mathrm{\α})}^2]\end{array}---\left(14\right)$

Formula (14) can be expressed as:

(U _or-w) ²+(U _oj-v) ²＝r ² (15)

Wherein, $w={U^{\′}}_{\mathrm{or}}+\frac{1}{2}(\mathrm{\α}-\frac{R_0}{X_0}\mathrm{\β}),v={U^{\′}}_{\mathrm{oj}}+\frac{1}{2}(\mathrm{\β}+\frac{R_0}{X_0}\mathrm{\α}),$

$r=\frac{1}{2}\sqrt{{(\mathrm{\α}-\frac{R_0}{X_0}\mathrm{\β})}^2+{(\mathrm{\β}+\frac{R_0}{X_0}\mathrm{\α})}^2}.$

Formula (15) represents U _or-U _ojin plane, the center of circle is that (w, v) radius is the equation of a circle of r.Due to R ₀, X ₀, α and β are independent of the value of x, and therefore w and v are also independent of element x.No matter what value is the parameter of element x get, and formula (15) is always set up, and for each source of trouble, real part and imaginary part at the voltage of same measuring point generation under any source of trouble parameter all meet same equation of a circle.Therefore, equation of a circle (15) is the fault model that can simultaneously be applied to soft fault and hard fault.And irrelevant with method of testing.Conclusions is that (element x) obtains for resistance the supposition source of trouble, if the source of trouble is electric capacity or inductance, can derives and obtain same conclusions.When circuit-under-test non-fault, output voltage is imaginary part is expressed as in fact with because formula (15) is independent of the parameter of element x, so with necessarily meet this formula, the characteristic locus of all sources of trouble all passes through a little

Known according to above analysis, for the same measuring point of tested mimic channel, under different elements fault condition,, under the condition of different faults source, measuring point records real part and an imaginary part corresponding equation of a circle separately of voltage.So by equation of a circle characteristic parameter corresponding to more each source of trouble, can whether can be distinguished in failure judgement source, there is one and different above if obtain three characteristic parameters of equation of a circle under two source of trouble conditions, these two sources of trouble belong to different ambiguity group so, if three characteristic parameters are identical, belong to same ambiguity group.

According to the above theoretical conclusion of deriving and obtaining, just can carry out ambiguity group identification to the source of trouble of mimic channel.But under actual conditions, the more difficult acquisition of Explicit Expression formula of equation of a circle (15), therefore the present invention proposes to obtain equation of a circle characteristic parameter by mimic channel emulation.As everyone knows, 2 definite straight lines, just can determine a circle (equation) at 3.Therefore the emulation that, only need to carry out the component parameters in three different faults sources to the source of trouble just can calculate three characteristic parameters of the equation of a circle of its correspondence.If three false voltages that emulation obtains are in a straight line, so corresponding fault signature can be expressed as the straight line of a certain slope, otherwise is just determined by formula (15).

Fig. 5 is the embodiment process flow diagram of mimic channel ambiguity group of the present invention recognition methods.As shown in Figure 5, mimic channel ambiguity group of the present invention recognition methods comprises the following steps:

S501: non-fault emulation:

Mimic channel is carried out to non-fault emulation, obtain the non-fault voltage of measuring point t

S502: make d=1.

S503: source of trouble fault simulation:

By the component parameters x of d the source of trouble _dchange to x _d1and x _d2carry out respectively emulation, obtain the false voltage of measuring point t, be designated as respectively ${\stackrel{\&CenterDot;}{U}}_1=U_{1r}+U_{1j}j,{\stackrel{\&CenterDot;}{U}}_2=U_{2r}+U_{2j}j.$ Parameter x _d1and x _d2operated by rotary motion x is set according to actual conditions _d1< x _d, x _d2> x _d.

S504: calculate circle characteristic parameter:

If $\frac{U_{1j}-U_{\mathrm{oj}}}{U_{1r}-U_{\mathrm{or}}}=\frac{U_{2j}-U_{\mathrm{oj}}}{U_{2r}-U_{\mathrm{or}}},$ $K_d=\frac{U_{1j}-U_{\mathrm{oj}}}{U_{1r}-U_{\mathrm{or}}},$ Order circle characteristic parameter w _d=1, v _d=-K _d, r _d=0, obtain circle characteristic parameter w otherwise solve following system of equations _d, v _d, r _d:

$\left\{\begin{array}{c}{(U_{\mathrm{or}}-w_d)}^2+{(U_{\mathrm{oj}}-v_d)}^2={r_d}^2\\ {(U_{1r}-w_d)}^2+{(U_{1j}-v_d)}^2={r_d}^2\\ {(U_{2r}-w_d)}^2+{(U_{2j}-v_d)}^2={r_d}^2\end{array}\right.---\left(16\right)$

S505: judge whether d=N _f, N _frepresent source of trouble quantity, if so, enter step S506, otherwise make d=d+1, return to step S503.

S506: the round characteristic parameter that more each source of trouble is corresponding, by three parameters all the identical source of trouble be classified as an ambiguity group.The element with different parameters is differentiable.The element with identical parameters is undistinguishable under current measuring point.

Embodiment

For implementation process of the present invention and effect are described, carry out simulating, verifying as an example of a side circuit example.Fig. 6 is mimic channel schematic diagram in embodiment.As shown in Figure 6, the mimic channel in the present embodiment is a bandwidth-limited circuit, and measuring point t is the node between element R1 and element R2, C1.First circuit is carried out to non-fault emulation, the non-fault voltage that obtains measuring point t is successively each source of trouble is carried out to fault simulation twice.Then calculate equation of a circle characteristic parameter corresponding to each source of trouble according to non-fault voltage and false voltage.Taking the 1st source of trouble resistance R 1 as example, its normal resistance values is 20k Ω, in the fault simulation of the present embodiment, the resistance value of its twice fault simulation is made as respectively to 10k Ω and 40k Ω, and the false voltage that measuring point t records is respectively ${\stackrel{\&CenterDot;}{U}}_1=(0.7202-0.3058j)V,{\stackrel{\&CenterDot;}{U}}_2=(0.2484-0.2902j)V.$ Due to 3 not point-blank, that is:

$\frac{U_{1j}-U_{\mathrm{oj}}}{U_{1r}-U_{\mathrm{or}}}=\frac{-0.3058+0.3534}{0.7202-0.4784}\&NotEqual;\frac{U_{2j}-U_{\mathrm{oj}}}{U_{2r}-U_{\mathrm{or}}}=\frac{-0.2902+0.3534}{0.2484-0.4784},$ Therefore the equation of a circle characteristic parameter of voltage substitution formula (16) calculated resistance R1 emulation being obtained.

$\begin{array}{c}\left\{\begin{array}{c}{(U_{\mathrm{or}}-w_1)}^2+{(U_{\mathrm{oj}}-v_1)}^2={r_1}^2\\ {(U_{1r}-w_1)}^2+{(U_{1j}-v_1)}^2={r_1}^2\\ {(U_{2r}-w_1)}^2+{(U_{2j}-v_1)}^2={r_1}^2\end{array}\right.\\ \&DoubleRightArrow;\left\{\begin{array}{c}{(0.4784-w_1)}^2+{(-0.3534-v_1)}^2=r^2\\ {(0.7202-w_1)}^2+{(-0.3058-v_1)}^2=r^2\\ {(0.2484-w_1)}^2+{(-0.2902-v_1)}^2=r^2\end{array}\right.\&DoubleRightArrow;\left\{\begin{array}{c}{w}_1=0.5\\ v_1=0.1768\\ r_1=0.5304\end{array}\right.\end{array}$

Table 1 is fault simulation output voltage and the model parameter table of the each source of trouble of mimic channel in embodiment.

Table 1

Fig. 7 draws according to equation of a circle characteristic parameter in table 1 the each source of trouble characteristic of correspondence circle obtaining.As shown in Figure 7, all source of trouble characteristic of correspondence circles all pass through non-fault voltage in Fig. 7, have 6 different circles, illustrate that 7 sources of trouble in the present embodiment have been divided into 6 ambiguity group, wherein resistance R 4 and resistance R 5 have identical characteristic circle, belong to an ambiguity group, and other elements respectively belong to an ambiguity group.Table 2 is the ambiguity group information of the present embodiment.

Ambiguity group	The source of trouble	Circle characteristic parameter (w, v, r)
			1	R1	(0.5000,0.1768),0.5304
2	R2	(0.4281,0.0791),0.4353
			3	R3	(0.2952,-0.4046),0.1902
4	R4,R5	(-0.4296,-1.0800),1.1627
			5	C1	(0.3574,-0.1687),0.2209
6	C2	(0.4096,-0.1079),0.2549

Table 2

According to transition function and Symbolic Analysis Method, the mimic channel in the present embodiment is carried out to ambiguity group identification, its result is consistent with result shown in table 2.Visible, the precision of the inventive method is identical with transition function and Symbolic Analysis Method, but advantage of the present invention is that its implementation is simple without using transition function, and ambiguity group recognition result and method of testing have nothing to do.

Although above the illustrative embodiment of the present invention is described; so that those skilled in the art understand the present invention; but should be clear; the invention is not restricted to the scope of embodiment; to those skilled in the art; as long as various variations appended claim limit and definite the spirit and scope of the present invention in, these variations are apparent, all utilize innovation and creation that the present invention conceives all at the row of protection.

Claims (2)

1. a mimic channel ambiguity group recognition methods, is characterized in that comprising the following steps:

S1: mimic channel is carried out to non-fault emulation, obtain the non-fault voltage of measuring point t

S2: make d=1;

S3: by the parameter x of d source of trouble element _dchange to x _d1and x _d2carry out respectively emulation, obtain the non-fault voltage of measuring point t, be designated as respectively ${\stackrel{\&CenterDot;}{U}}_1=U_{1r}+U_{1j}j,{\stackrel{\&CenterDot;}{U}}_2=U_{2r}+U_{2j}j;$

S4: if $\frac{U_{1j}-U_{\mathrm{oj}}}{U_{1r}-U_{\mathrm{or}}}=\frac{U_{2j}-U_{\mathrm{oj}}}{U_{2r}-U_{\mathrm{or}}},$ $K_d=\frac{U_{1j}-U_{\mathrm{oj}}}{U_{1r}-U_{\mathrm{or}}},$ Order circle characteristic parameter w _d=1, v _d=-K _d, r _d=0, obtain circle characteristic parameter w otherwise solve following system of equations _d, v _d, r _d:

$\left\{\begin{array}{c}{(U_{\mathrm{or}}-w_d)}^2+{(U_{\mathrm{oj}}-v_d)}^2={r_d}^2\\ {(U_{1r}-w_d)}^2+{(U_{1j}-v_d)}^2={r_d}^2\\ {(U_{2r}-w_d)}^2+{(U_{2j}-v_d)}^2={r_d}^2\end{array}\right.$

S5: judge whether d=N _f, if so, enter step S6, otherwise make d=d+1, return to step S3;

S6: the round characteristic parameter that more each source of trouble is corresponding, by three parameters all the identical source of trouble be classified as an ambiguity group.

2. mimic channel ambiguity group according to claim 1 recognition methods, is characterized in that, described parameter x _d1< x _d, x _d2> x _d.