CN101299147B - Closed-loop control method and device of optical fiber current transformer system noise suppression - Google Patents

Abstract

An embodiment of the invention provides a closed-loop control method for inhibiting the noise of the optical fiber current mutual inductor system and a device thereof. Firstly a mathematical model of the optical fiber current mutual inductor is introduced with a disturbance input signal. Afterwards a control algorithm is used for executing feedback processing to the input signal in the mathematical model for inhibiting the disturbance input signal, wherein the disturbance input signal is mainly the optical path of the system. Through the optimization process, the effect caused by the noise of the system optical path can be effectively inhibited. The precision of system measurement is increased and furthermore the system performance of the optical fiber current mutual inductor is increased.

Description

Closed loop control method and device that optical fiber current transformer system noise suppresses

Technical field

The present invention relates to the optical fiber current mutual inductor field, relate in particular to closed loop control method and device that a kind of optical fiber current transformer system noise suppresses.

Background technology

Development along with the current transformer technology, optical fiber current mutual inductor has obtained increasing application, because it adopts the media of optical fiber as induction of signal and transmission, not only good insulation preformance, be subjected to the influence of electromagnetic interference (EMI) also little, and project organization is simple, volume is little, light weight, and manufacturing cost is also lower.But in actual applications, because the light path noise of optical fiber current mutual inductor internal system, it is the measuring accuracy that the system disturbance signal can have influence on system, therefore suppressing the intrasystem light path noise of optical fiber current mutual inductor becomes the problem that presses for solution, be illustrated in figure 1 as the closed loop controlling structure synoptic diagram of optical fiber current mutual inductor of the prior art system, among the figure:

In the input signal owing to Faraday effect (Faraday effect) carries non-reciprocal phase difference Δ φ _sThis has carried non-reciprocal phase difference Δ φ _sInput signal successively by detector and preceding discharge road, analog to digital converter (A/D converter) and demodulating unit, arrive digitial controller at last and obtain output signal; And described digitial controller also can be with this output signal as feedback signal successively by behind digital to analog converter (D/A converter) and driver and the phase-modulator, form feedback phase And balance out the non-reciprocal phase difference Δ φ that produces owing to Faraday effect thus _sThereby, form closed-loop control.

Because in actual applications, non-reciprocal phase is poor

In include the noise of various systems simultaneously, wherein the light path noise is the overriding noise source of system, so just limited the measuring accuracy of system, and do not consider the light path noise that how to suppress system in the design of Controller of the prior art, thereby make the measuring accuracy of system can be subjected to the system light path The noise, reduced the performance of optical fiber current mutual inductor system.

Summary of the invention

Embodiment of the present invention technical matters to be solved is to provide a kind of closed loop control method and device of optical fiber current transformer system noise inhibition, can effectively suppress the influence that the system light path noise is brought, thereby improve the precision of systematic survey.

The closed loop control method that embodiment of the present invention provides a kind of optical fiber current transformer system noise to suppress comprises:

The disturbance input signal of descriptive system light path noise is delivered in the mathematical model of optical fiber current mutual inductor system;

According to the robust control algorithm state equation of describing described system mathematic model is optimized, obtains the robust guaranteed cost control rule of described system;

In the mathematical model with the described optical fiber current mutual inductor of resulting system robust guaranteed cost control rule introducing system, suppress described disturbance input signal.

The closed-loop control device that embodiment of the present invention also provides a kind of optical fiber current transformer system noise to suppress comprises:

The disturbing signal processing unit is arranged on the controller in the optical fiber current mutual inductor system;

Comprise in the described disturbing signal processing unit:

The Control and Optimization module is used for according to the robust control algorithm state equation of describing described system mathematic model being optimized, and obtains the robust guaranteed cost control rule of described system; Wherein, in the mathematical model with the described optical fiber current mutual inductor of resulting robust guaranteed cost control rule introducing system, be used for suppressing described disturbance input signal.

The above installs integrated being arranged in the described controller, or is arranged to independent functional entity.

By the above-mentioned technical scheme that provides as can be seen, at first in the mathematical model of optical fiber current mutual inductor system, introduce the disturbance input signal; Utilize control algolithm that the input signal in the described mathematical model is carried out feedback processing then, suppress described disturbance input signal, disturbance input signal described here is mainly the light path noise of system.After such optimization process, just can effectively suppress the influence that the system light path noise is brought, improve the precision of systematic survey, and then improved the system performance of optical fiber current mutual inductor.

Description of drawings

Fig. 1 is the closed loop controlling structure synoptic diagram of optical fiber current mutual inductor of the prior art system;

Fig. 2 is the schematic flow sheet of the described closed loop control method of embodiment of the present invention;

Fig. 3 is the frame structure synoptic diagram of the optical fiber current mutual inductor system of embodiment of the present invention equivalence;

Fig. 4 is the analog simulation synoptic diagram of disturbance input signal;

The system output emulation synoptic diagram of Fig. 5 for drawing according to former control algolithm;

Fig. 6 exports the emulation synoptic diagram for the system that embodiment of the present invention drew;

Fig. 7 is the structural representation of the described closed-loop control device of embodiment of the present invention.

Embodiment

Embodiment of the present invention provides a kind of closed loop control method and device that optical fiber current transformer system noise suppresses that be used for.By in the mathematical model of optical fiber current mutual inductor system, introducing the disturbance input signal; Utilize control algolithm that the input signal in the described mathematical model is carried out feedback processing then, control algolithm described here can be the robust control algorithm.Specifically can be to utilize the robust control algorithm that the state equation of describing described system mathematic model is optimized calculating, obtain the robust guaranteed cost control rule of described system; And then in the mathematical model with the described optical fiber current mutual inductor of resulting system robust guaranteed cost control rule introducing system, suppress this disturbance input signal.When having the light path noise in the optical fiber current mutual inductor system, just can utilize the robust guaranteed cost control rule of system effectively to suppress this light path noise like this, improve the measuring accuracy of system, and then improved the system performance of optical fiber current mutual inductor.

For better describing embodiment of the present invention, now in conjunction with the accompanying drawings the specific embodiment of the present invention is described, be illustrated in figure 2 as the schematic flow sheet of the described closed loop control method of embodiment of the present invention, described method comprises:

Step 21: in the mathematical model of optical fiber current mutual inductor system, introduce disturbance input signal parameter.

Be exactly specifically, when the mathematical model of optical fiber current mutual inductor system is set up, in input signal, introduce disturbing signal, the light path noise of taking into account system just, be illustrated in figure 3 as the frame structure synoptic diagram of the optical fiber current mutual inductor system model of equivalence, w is the disturbance input signal among the figure, and u is a feedback control signal, z is an output signal, k ₁+ k ' is forward path gain, k ₂Feedback factor for system; K wherein ₁The parameter k ' among+k ' is used for representing the uncertain factor in the system model, and the variation of this uncertain factor system forward channel gain that mainly to be light source light power, detector and preamplification gain cause with variation of temperature causes.

System model with accompanying drawing 3 is an example, owing to the existence of k ', has introduced the uncertainty of systematic parameter.

The mathematical model of optical fiber current mutual inductor system is: $x(k+1)=\left[\begin{array}{cc}0& 1\\ -({\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="S2008101049274E00031.png"\; state="\{\{state\}\}">k</figure-callout>}}_1+k^{\&prime;})k_2& -2({\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="S2008101049274E00031.png"\; state="\{\{state\}\}">k</figure-callout>}}_1+0.2k^{\&prime;})k_2\end{array}\right]x\left(k\right)+\left[\begin{array}{c}0\\ -({\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="S2008101049274E00031.png"\; state="\{\{state\}\}">k</figure-callout>}}_1+k^{\&prime;})k_2\end{array}\right]u\left(k\right)+\left[\begin{array}{c}0\\ k_1\end{array}\right]w\left(k\right)---\left(5\right)$

z(k)＝[1?0]x(k)+0.5u(k)

With above-mentioned simplified formula, can the optical fiber current mutual inductor system be described by following state equation:

x(k+1)＝(G+ΔG)x(k)+(H ₁+ΔH ₁)u(k)+H ₂w(k) (6)

z(k)＝Cx(k)+Du(k)

Wherein: x (k) ∈ R ⁿBe the state variable of system, u (k) is a feedback control signal, and w (k) is the disturbance input signal for noise, and z (k) is a system output signal; G wherein, H ₁, H ₂, C and D parameter be the known solid constant matrices of descriptive system model; And Δ G and Δ H ₁Be the probabilistic unknown real matrix of parameter k ' in the reflection system model, because the variation of k ' is a bounded in real system, so Δ G and Δ H ₁Be norm bounded, and have following form:

[ΔGΔH ₁]＝FM[E ₁?E ₂] (7)

M in the wherein above-mentioned formula 7 satisfies M ^TThe uncertain matrix of M≤I; Parameter F, E ₁And E ₂Be known constant matrices, be used for representing the structural information of uncertain parameter.

In addition, according to the span of optical fiber current mutual inductor system: k ₁=0.1, k ₂=1, | k ' |≤0.1, and can know the expression formula of above-mentioned each known solid constant matrices by inference by above-mentioned formula 5,6 and 7:

$G=\left[\begin{array}{cc}0& 1\\ -0.1& -0.2\end{array}\right],$ $H_1=\left[\begin{array}{c}0\\ -0.1\end{array}\right],$ $H_2=\left[\begin{array}{c}0\\ 0.1\end{array}\right]$ C＝[1?0]，D＝0.5

F＝[0?1] ^T，E ₁＝[-0.1?-0.04]，E ₂＝-0.1

The mathematical model of optical fiber current mutual inductor system like this, just can be described with above-mentioned formula 6 and 7.

Step 22: utilize control algolithm that the input signal in the described mathematical model is carried out feedback processing.

Be exactly specifically, when operation according to above step 21, in the mathematical model of optical fiber current mutual inductor system, introduce after the disturbance input signal, just can utilize control algolithm that the input signal in the described mathematical model is carried out feedback processing, suppress the disturbance input signal of being introduced.Disturbance input signal described here can be the disturbing signal of a finite energy, and it mainly is to be used for the light path noise of descriptive system.

More than carrying out the process of feedback processing, specifically can be according to the robust control algorithm state equation of describing described system mathematic model to be optimized calculating, obtains the robust guaranteed cost control rule of described system; And then in the mathematical model with the described optical fiber current mutual inductor of resulting system robust guaranteed cost control rule introducing system, thereby suppress described disturbance input signal.

In addition, except the robust guaranteed cost control rule that obtains system according to the robust control algorithm, can also come the state equation of describing described system mathematic model is optimized calculating according to other control algolithm.Be calculated as example and further specify to be optimized below according to the robust control algorithm:

Utilizing the robust control algorithm to be optimized calculating, be at the index request of system and the parameter uncertainty of system, clear and definite following design of Controller index:

1) closed-loop system is asymptotically stable;

2) when disturbance input signal w (k) is regarded as the disturbing signal of a finite energy, closed loop transfer function, T (z) from w (k) to output signal z (k) will satisfy ‖ T (z) ‖＜γ, γ＞0th wherein, given scalar, being used for the expression system suppresses the ability of undesired signal.

Like this, utilize the robust control algorithm that the state equation of described system mathematic model is optimized calculating, obtain a state feedback control law u (k), make in the optical fiber current mutual inductor system, the uncertainty of the systematic parameter described in for example above-mentioned formula 7, and closed-loop system can both satisfy above clear and definite design of Controller index.

The u here (k) can be called a robust H of 6 descriptive systems of above-mentioned formula _∞The guaranteed cost control rule.

Specifically, for given constant γ＞0 and above-mentioned formula 6, have guaranteed cost control rule u (k), and if only if when having constant ε＞0 and symmetric positive definite matrix Q and matrix N, can obtain following LMI:

$\left[\begin{array}{ccccc}-Q& 0& {(\mathrm{GQ}+H_{1}N)}^T& {(E_{1}Q+E_{2}N)}^T& {(\mathrm{CQ}+\mathrm{DN})}^T\\ 0& -{\mathrm{\&gamma;}}^{2}I& H_2^T& 0& 0\\ \mathrm{GQ}+H_{1}N& H_2& -Q+\mathrm{\&epsiv;}{\mathrm{FF}}^T& 0& 0\\ E_{1}Q+E_{2}N& 0& 0& -\mathrm{\&epsiv;I}& 0\\ \mathrm{CQ}+\mathrm{DN}& 0& 0& 0& -I\end{array}\right]<0---\left(9\right)$

When above-mentioned formula 9 has feasible solution ε, a Q, N, just can obtain N, Q value by finding the solution above-mentioned formula 9, so just can obtain feedback control signal u (k)=NQ ^-1X (k), a robust H of Here it is said system state equation (formula 6) _∞The guaranteed cost control rule.

Because above-mentioned formula 9 is LMIs, therefore the solver (feasp) that can use in LMI (LMI) the instrument feather cockscomb is found the solution this LMI.

Suppose given γ=0.1, so just can obtain the robust H of optical fiber current mutual inductor system _∞Guaranteed cost control rule: u (k)=[1.9796-0.0117] x (k).

Then with above-mentioned robust H _∞Guaranteed cost control rule u (k) is incorporated in the mathematical model of described optical fiber current mutual inductor system, so just can suppress described disturbance input signal w and (k).

For instance, add disturbance input signal w (k) in the realistic model of optical fiber current mutual inductor system, be illustrated in figure 4 as the analog simulation synoptic diagram of disturbance input signal, w among the figure (k) is for average is 0, variance is the noise signal of 1 Normal Distribution.

Then with robust H _∞In control law u (k) the substitution simulation mathematical model that guaranteed cost control rule method for designing obtains, draw corresponding emulation input results.Here can will compare according to the emulation output simulation result that result and original control algolithm drew that embodiment of the present invention drew, be illustrated in figure 5 as the system's output emulation synoptic diagram that draws according to former control algolithm, be illustrated in figure 6 as the system output emulation synoptic diagram that draws according to embodiment of the present invention, the contrast from figure as can be seen: adopt robust H _∞System's output of guaranteed cost control rule will significantly improve system to the light path capability of restraining noise, and system output signal is more stable, has so just improved the precision of systematic survey, and then has improved the system performance of optical fiber current mutual inductor.

The closed-loop control device that embodiment of the present invention also provides a kind of optical fiber current transformer system noise to suppress, be illustrated in figure 7 as the structural representation of described device, described device comprises signal processing unit, described signal processing unit, be arranged on the controller in the optical fiber current mutual inductor system, be used for utilizing control algolithm that the input signal of the mathematical model of optical fiber current mutual inductor system is carried out feedback processing, suppress the disturbance input signal introduced in the described mathematical model, and then improve the measuring accuracy of optical fiber current mutual inductor system.

In described signal processing unit, can also comprise the Control and Optimization module, described Control and Optimization module is used for according to the robust control algorithm state equation of describing described system mathematic model being optimized calculating, obtains the robust guaranteed cost control rule of described system.

Wherein, in the mathematical model with the described optical fiber current mutual inductor of resulting robust guaranteed cost control rule introducing system, be used for suppressing described disturbance input signal.

Above-described device can integratedly be arranged in the described controller, also can be arranged to independent functional entity, maintains the connection with described controller.

In sum, embodiment of the present invention can effectively suppress the influence that the system light path noise is brought, and improves the precision of systematic survey, and then has improved the performance index of optical fiber current mutual inductor system.

The above; only be the preferable embodiment of the present invention; but protection scope of the present invention is not limited thereto; anyly be familiar with those skilled in the art in the technical scope that the embodiment of the invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection domain of claim.

Claims (2)

1. the closed-loop control device that optical fiber current transformer system noise suppresses is characterized in that, comprising:

The disturbing signal processing unit is arranged on the controller in the optical fiber current mutual inductor system, is used for utilizing control algolithm that the input signal of the mathematical model of optical fiber current mutual inductor system is carried out feedback processing, suppresses the disturbance input signal in the described mathematical model;

Wherein, comprise in the described disturbing signal processing unit:

The Control and Optimization module is used for according to the robust control algorithm state equation of describing described optical fiber current mutual inductor system mathematic model being optimized, and obtains the robust guaranteed cost control rule of described optical fiber current mutual inductor system; Wherein, in the mathematical model with the described optical fiber current mutual inductor of resulting robust guaranteed cost control rule introducing system, be used for suppressing described disturbance input signal.

2. the closed-loop control device that optical fiber current transformer system noise as claimed in claim 1 suppresses is characterized in that described device is integrated to be arranged in the described controller, or is arranged to independent functional entity.

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