CN103474949B - The setting method of a kind of self adaptation three section protection and device - Google Patents

Abstract

The present invention relates to a kind of self adaptation three section protection method; based on current quick, band time limit current quick and three kinds of salvos of overcurrent protection; comprise the steps, 1) the most accurately gather voltage and electric current by adaptive filter algorithm, obtain fundamental current amplitude i₁；2) three kinds of salvos are adjusted respectively obtain its correspondence setting valve and: 3) i₁>, then carry out current quick measure, otherwise go to step 4)；4) through T after a while_IIAfter, if_­i₁>, then carry out the current quick measure of band time limit, otherwise go to step 5)；5) through T after a while_IIIAfter, if i₁>, then carry out overcurrent protection measure, otherwise terminate this three section protection method.Have the beneficial effect that and improve distribution network reliability of operation and stability, do not changing sensitivity and the accuracy substantially increasing protection while three sections of electric currents protect ultimate principle.

Description

The setting method of a kind of self adaptation three section protection and device

Technical field

The present invention relates to relay protection field, particularly relate to setting method and the device of a kind of self adaptation three section protection.

Background technology

Relay protection is important technical measures and the means of safe operation of power system.Traditional relay protection setting value Mostly obtained by calculated off line according to power system maximum operational mode, and verify its guarantor by power system minimum operational mode The sensitivity protected, it is impossible to repair in real time along with the method for operation, topological structure, fault type, system intrinsic parameter and the change of load Positive setting valve.This setting mode has the drawback that protection definite value is typically determined by the most serious service condition, although Ke Yibao Card under the various methods of operation, protection can correct operation, but the fault for occurring under non-maximum running status cannot be real Existing best protection effect；Setting valve is once it is determined that will not change in a short time, it is impossible to adapt to power system topological structure, failure classes The change of device parameter, the method for operation and load in type, system, when system changes, the selectivity of protection, sensitivity meeting Serious reduction, even loses protection domain.Along with the expansion of power system scale, distribution line network structure is with power-supplying forms also Increasingly sophisticated, traditional distribution line protection the most increasingly can not meet the requirement of power system.

Summary of the invention

Present invention aim to overcome that the deficiency of above prior art, it is provided that the setting device of a kind of self adaptation three section protection And method, specifically have techniques below scheme to realize:

Described self adaptation three section protection device, including

Voltage x current calculates module: according to gathering the voltage x current data that current acquisition arrives, obtain the amplitude of voltage x current And phase angle；

SCADA system: be responsible for the collection of signal and the arrangement of system information；

Adaptive guard module: SCADA system is sent the operation information of the distribution line come and by voltammeter The real-time amplitude data calculating the voltage x current that module is sent processes, and calculates the real-time setting valve of three section protection, it is achieved from Adapt to adjusting of three sect current protection；

Communication module: make each module and SCADA system machine carry out communication, thus the distant place realizing information is transmitted and exchange；

And show and input module: primary system figure, measurement data, protection information, fault waveform, described electricity can be shown Current voltage computing module, communication module and display and input module communicate to connect with adaptive guard module respectively, described logical News module communicates to connect with SCADA system；

Also include that switching value input circuit, described switching value input circuit are connected with the external apparatus interface of this device, bag Including optocoupler, current-limiting resistance, filter unit and stabilivolt, described stabilivolt, current-limiting resistance and filter unit are connected to light successively Light emitting diode one end of coupling, described filter unit is connected with resistance by electric capacity and forms, and described voltage x current calculates module and includes Analogue signal acquisition circuit, level shifting circuit, a/d converter and dsp processor, described analogue signal acquisition circuit, level Change-over circuit, a/d converter are sequentially connected with dsp processor, and described analogue signal acquisition circuit includes bipolar operational amplifier IC chip and current transformer, described bipolar operational amplifier IC chip is connected with current transformer, institute State level shifting circuit to be composed in series by two bipolar operational amplifier IC chips.

The further design of described self adaptation three section protection device is, described display and input module include single-chip microcomputer, Liquid crystal display screen display circuit, keyboard interface circuit and LED display circuit, described liquid crystal display screen display circuit, keyboard interface circuit And LED display circuit is connected with described single chip communication respectively.

Use the self adaptation three section protection method of described self adaptation three section protection device, during based on current quick, band Threshold currents fast tripping protection and three kinds of salvos of overcurrent protection, it is characterised in that the method determines above-mentioned salvo Action current real-time voltage current amplitude, the calculated relationship of distribution line parameter and setting valve, described setting valve can be automatic The change of the voltage x current amplitude that ground collects along with distribution line parameter and device and change, described self adaptation three sections guarantor Maintaining method comprises the steps,

1) the most accurately gather voltage and electric current by adaptive filter algorithm, obtain fundamental current amplitude i₁；

2) three kinds of salvos adjusted respectively obtain the setting valve of its correspondence:

Current quick is adjusted: the actual operating current according to power system and malfunction in real time, the most true Determine fault type coefficient when fault occurs and system power supply side practical impedance, and then calculate current quick setting valve I_DZ.I；

Band time limit current quick is adjusted: when next adjacent circuit uses self-adaptive current fast tripping protection, according to Time limit quick-break current protection safety factor determines oneself of this circuit with next circuit self-adaptive current fast tripping protection setting valve adjacent Adapt to current quick setting valve I_DZ.II；

Overcurrent protection is adjusted: can obtain its setting valve according to the self-starting coefficient of this circuit and Real-time Load electric current I_DZ.III, to adapt to the change of load and the method for operation；

3)i₁>I_DZ.I, then carry out current quick measure, otherwise go to step 4)；

4) through T after a while_IIAfter, if i₁>I_DZ.II, then carry out the current quick measure of band time limit, otherwise go to step Rapid 5)；

5) through T after a while_IIIAfter, if i₁>I_DZ.III, then carry out overcurrent protection measure, otherwise terminate these three sections guarantors Maintaining method；

Described adaptive filter algorithm comprises the steps:

A) set the fourier expansion form of input signal i (t) as:

In formula, f_nIt is the frequency of nth harmonic electric current, I_nFor the amplitude of harmonic current,For the phase angle of harmonic current, i₁(t) For fundamental current, i_nT () is all harmonic current sums in addition to first-harmonic；

B) formulate a digital filter to be filtered input signal i (t) processing, obtain filtered process after i (t) Fourier expansion form is:

$i\left(t\right)=\underset{n=0}{\overset{\mathrm{\∞}}{\Σ}}\[a_n\sin \left({\mathrm{n\ω}}_{1}t\right)+b_{n}cos\left({\mathrm{n\ω}}_{1}t\right)\]---\left(5\right)$

x₁(t)=a₁sin(ω₁t)+b₁cos(ω₁t) (6)

In formula, n is natural number, n=0,1,2 ...；w₁It it is the angular frequency of fundamental current；a_nAnd b_nEach represent cosine term and The sine wave period of each harmonic, a₀For direct current component value, a₁And b₁For fundamental current amplitude；C) base is obtained according to formula (5)-(6) Ripple current amplitude i₁For:

$i_1=\sqrt{\frac{{\mathrm{\α}}_1^2+b_1^2}{2}}---\left(7\right)$

Length H=hT when the sampling period_WDuring=T, a in formula (7)₁And b₁It is represented by:

$\left\{\begin{array}{c}{a}_1=\frac{1}{T}{\∫}_t^{t+T}i\left(\mathrm{\τ}\right)\cos \left(\mathrm{\ω}\mathrm{\τ}\right)d\mathrm{\τ}=\frac{1}{{\mathrm{hT}}_W}{\∫}_t^{t+{\mathrm{hT}}_w}i\left(\mathrm{\τ}\right)\cos \left(w\mathrm{\τ}\right)d\mathrm{\τ}\\ b_1=\frac{1}{T}{\∫}_t^{t+T}i\left(\mathrm{\τ}\right)\sin \left(\mathrm{\ω}\mathrm{\τ}\right)d\mathrm{\τ}=\frac{1}{{\mathrm{hT}}_W}{\∫}_t^{t+{\mathrm{hT}}_w}i\left(\mathrm{\τ}\right)\sin \left(w\mathrm{\τ}\right)d\mathrm{\τ}\end{array}\right.---\left(8\right)$

Wherein Tw is the sampling interval, and h is the number of samples a cycle, and ω=2 π f, f=50Hz are first-harmonic

Power frequency, T=1/f, h=48；

D) after gathering each sample, by i₁With protection definite value I_DZCompare, if i₁Calculating knot

Fruit is more than I_DZ, then corresponding exception handles is entered into；

In described step b), digital filter is based on following iterative formula:

C (k)=d (k)-y ' (k)=X^T(k)W^*(k)-X^T(k)W(k) (1)

E (k)=y (k)-y'(k)=d (k)+ξ (k)-y'(k)=c (k)+ξ (k) (2)

W (k+1)=W (k)+2 μ e (k) X (k) (3)

In formula (1)-(3), X (k) is the input signal in k moment, and W (k) is the weight coefficient of sef-adapting filter, W* (k) Being the weight coefficient of unknown system, d (k) is desired signal, y'(k) it is the output signal of sef-adapting filter, e (k) is ξ (k) With the error of c (k), ξ (k) is noise signal, and c (k) is tracking error signal, and μ is step factor, and X (k) is reference input letter Number；

Described digital filter, by the continuous iteration of formula (1) (2) (3), controls error e (k) feedback minimum, W (k) to During W* (k) revises, make filtered output signals y'(k) it is similar to desired output d (k), to guarantee described each salvo Middle voltage, the acquisition precision of electric current and speed, according to iterative formula (1)-(3), setting noise signal ξ (k) is in (t), it is desirable to Signal d (k) is i₁(t), reference-input signal X (k) be i (t), W (k) initial value be Arbitrary Transfer Function, if t=(0,1,2 ... K), μ is beginning iteration after step factor, is fed back by error e (k), and W (k) constantly approximates to W* (k), makes y'(k) automatic tracing Change i₁T (), completes the filtering to input signal i (t).

The further design of described self adaptation three section protection method is, described step 2) in the adjusting of current quick Formula is:

$I_{DZ.I}=\frac{K_K^I{K}_{d}E}{Z_s+ZL}---\left(9\right)$

In formulaFor current quick safety factor, take 1.2-1.3；E is system equivalent source phase electromotive force；Z is for be protected Protect circuit unit length impedance；L is the distance of trouble point and protection installation place.

The further design of described self adaptation three section protection method is, described step 2) in band time limit quick-break current protection Tuning formulae be:

$I_{DZ.II}=K_K^{II}{I}_{DZ.I.2}$ $\left(10\right)$

In formulaBand time limit quick-break current protection safety factor, takesI_DZ.I.2For next circuit self adaptation adjacent Current quick setting valve.

The further design of described self adaptation three section protection method is, described step 2) in self-adapted over-current protection Tuning formulae is:

$I_{DZ.III}=\frac{K_K^{III}{K}_{SS}}{K_{RE}}{I}_{line}---\left(11\right)$

I in formula_DZ.IIIFor this circuit self-adapted over-current protection setting valve；For overcurrent protection safety factor, takeK_ssFor self-starting coefficient, take K_ss=1；K_reFor drop-off to pick-up radio, take 0.85-0.95；I_lineBearing in real time for this circuit Charged current；

The overcurrent protection of this circuit also should meet:

$I_{DZ.III}=K_K^{{\mathrm{III}}^{\′}}{I}_{DZ.III.2}---\left(12\right)$

In formulaFor overcurrent protection coefficient, takeI_DZ.III.2Fixed for next circuit overcurrent protection adjacent Value,

The setting valve I of overcurrent protection_DZ.IIIThe greater in modus ponens (11), (12).

Advantages of the present invention is as follows:

(1) method that the present invention provides can automatically change the setting valve of protection according to the change of the distribution line method of operation And performance, so that protection is in optimum Working.Under the method for operation of change, the selectivity of adaptive guard is with quick Property significantly better than regular distribution lines protect, improve distribution network reliability of operation and stability, do not changing three sections of electricity Stream substantially increases sensitivity and the accuracy of protection while protecting ultimate principle.

(2) the apparatus moduleization design that the present invention provides, in order to ensure precision and the reliability that adaptive guard calculates, if Count voltage x current and calculated module, have employed self adapting digital filtering algorithm, improve voltage x current amplitude in protection system The accuracy and speed calculated.

Accompanying drawing explanation

Fig. 1 is the setting method flow chart of described self adaptation three section protection.

Fig. 2 is the design principle figure of described sef-adapting filter.

Fig. 3 is the module diagram of the setting device of described self adaptation three section protection.

Fig. 4 is the circuit diagram of described analogue signal acquisition circuit.

Fig. 5 is the circuit diagram of described level shifting circuit.

Fig. 6 is keyboard interface circuit figure.

Fig. 7 is the circuit diagram of liquid crystal display screen display circuit.

Fig. 8 is the circuit diagram of single-chip microcomputer.

Fig. 9 is LED display circuit figure.

Figure 10 is switching value input circuit figure.

Detailed description of the invention

Below in conjunction with the accompanying drawings the present invention program is described in detail.

Such as Fig. 1, the self adaptation three section protection method that the present embodiment provides, based on threshold currents speed when current quick, band Disconnected protection and three kinds of salvos of overcurrent protection.The method determines the action current real-time voltage electricity of above-mentioned salvo Stream amplitude, distribution line parameter and the calculated relationship of setting valve, setting valve can be automatically along with distribution line parameter and dress Putting the change of the voltage x current amplitude collected and change, self adaptation three section protection method comprises the steps,

1) the most accurately gather voltage and electric current by adaptive filter algorithm, obtain fundamental current amplitude i₁；

2), under current time, three kinds of salvos are adjusted respectively and obtain the setting valve of its correspondence:

Current quick is adjusted: the actual operating current according to power system and malfunction in real time, the most true Determine fault type coefficient when fault occurs and system power supply side practical impedance, and then calculate current quick setting valve I_DZ.I；

Band time limit current quick is adjusted: when next adjacent circuit uses self-adaptive current fast tripping protection, according to Time limit quick-break current protection safety factor determines oneself of this circuit with next circuit self-adaptive current fast tripping protection setting valve adjacent Adapt to current quick setting valve I_DZ.II；

Overcurrent protection is adjusted: can obtain its setting valve according to the self-starting coefficient of this circuit and Real-time Load electric current I_DZ.III, to adapt to the change of load and the method for operation；

3)i₁>I_DZ.I, then carry out current quick measure, otherwise go to step 4)；

4) through T after a while_IIAfter, if i₁>I_DZ.II, then carry out the current quick measure of band time limit, otherwise go to step Rapid 5)；

5) through T after a while_IIIAfter, if i₁>I_DZ.III, then carry out overcurrent protection measure, otherwise terminate these three sections guarantors Maintaining method.

In the present embodiment, adaptive filter algorithm specifically includes following steps:

A) set the fourier expansion form of input signal i (t) as:

In formula, f_nIt is the frequency of nth harmonic electric current, I_nFor the amplitude of harmonic current,For the phase angle of harmonic current, i₁(t) For fundamental current, i_nT () is all harmonic current sums in addition to first-harmonic.

B) formulate a digital filter to be filtered input signal i (t) processing, obtain filtered process after i (t) Fourier expansion form is:

$i\left(t\right)=\underset{n=0}{\overset{\mathrm{\∞}}{\Σ}}\[a_n\sin \left({\mathrm{n\ω}}_{1}t\right)+b_{n}cos\left({\mathrm{n\ω}}_{1}t\right)\]---\left(5\right)$

x₁(t)=a₁sin(ω₁t)+b₁cos(ω₁t) (6)

In formula, n is natural number, n=0,1,2 ...；w₁It it is the angular frequency of fundamental current；a_nAnd b_nEach represent cosine term and The sine wave period of each harmonic, a₀For direct current component value, a₁And b₁For fundamental current amplitude.

C) fundamental current amplitude i is obtained according to formula (5)-(6)₁For:

$i_1=\sqrt{\frac{a_1^2+b_1^2}{2}}---\left(7\right)$

Length H=hT when the sampling period_WDuring=T, a in formula (7)₁And b₁It is represented by:

$\left\{\begin{array}{c}{a}_1=\frac{1}{T}{\∫}_t^{t+T}i\left(\mathrm{\τ}\right)\cos \left(\mathrm{\ω}\mathrm{\τ}\right)d\mathrm{\τ}=\frac{1}{{\mathrm{hT}}_W}{\∫}_t^{t+{\mathrm{hT}}_w}i\left(\mathrm{\τ}\right)\cos \left(w\mathrm{\τ}\right)d\mathrm{\τ}\\ b_1=\frac{1}{T}{\∫}_t^{t+T}i\left(\mathrm{\τ}\right)\sin \left(\mathrm{\ω}\mathrm{\τ}\right)d\mathrm{\τ}=\frac{1}{{\mathrm{hT}}_W}{\∫}_t^{t+{\mathrm{hT}}_w}i\left(\mathrm{\τ}\right)\sin \left(w\mathrm{\τ}\right)d\mathrm{\τ}\end{array}\right.---\left(8\right)$

Wherein Tw is the sampling interval, and h is the number of samples a cycle, and ω=2 π f, f=50Hz are fundamental current frequency Rate, T=1/f, h=48；4) after gathering each sample, by i₁With protection definite value I_DZCompare, if i₁Calculating knot Fruit is more than I_DZ, then corresponding exception handles is entered into.

As in figure 2 it is shown, digital filter is based on following iterative formula in step b):

C (k)=d (k)-y ' (k)=X^T(k)W^*(k)-X^T(k)W(k) (1)

E (k)=y (k)-y'(k)=d (k)+ξ (k)-y'(k)=c (k)+ξ (k) (2)

W (k+1)=W (k)+2 μ e (k) X (k) (3)

In formula (1)-(3), X (k) is the input signal in k moment, and W (k) is the weight coefficient of sef-adapting filter, W* (k) Being the weight coefficient of unknown system, d (k) is desired signal, y'(k) it is the output signal of sef-adapting filter, e (k) is ξ (k) With the error of c (k), ξ (k) is noise signal, and c (k) is tracking error signal, and μ is step factor, and X (k) is reference input letter Number.

The digital filter continuous iteration by formula (1) (2) (3), controls error e (k) feedback minimum, at W (k) to W* (k) revise during, make filtered output signals y'(k) be similar to desired output d (k), with guarantee voltage in each salvo, The acquisition precision of electric current and speed, according to iterative formula (1)-(3), setting noise signal ξ (k) is in (t), it is desirable to signal d (k) For i₁(t), reference-input signal X (k) be i (t), W (k) initial value be Arbitrary Transfer Function, if t=(0,1,2 ... k), μ be step Starting iteration after the long factor, fed back by error e (k), W (k) constantly approximates to W* (k), makes y'(k) the change i of automatic tracing₁ T (), completes the filtering to input signal i (t).

Step 2) in the tuning formulae of current quick be:

$I_{DZ.I}=\frac{K_K^I{K}_{d}E}{Z_s+ZL}---\left(9\right)$

In formulaFor current quick safety factor, take 1.2-1.3；E is system equivalent source phase electromotive force；Z is for be protected Protect circuit unit length impedance；L is the distance of trouble point and protection installation place.

Step 2) in the tuning formulae of band time limit quick-break current protection be:

$I_{DZ.II}=K_K^{II}{I}_{DZ.I.2}---\left(10\right)$

In formulaBand time limit quick-break current protection safety factor, takesI_DZ.I.2For next circuit self adaptation adjacent Current quick setting valve.

Step 2) in the tuning formulae of self-adapted over-current protection be:

$I_{DZ.III}=\frac{K_K^{III}{K}_{SS}}{K_{RE}}{I}_{line}---\left(11\right)$

I in formula_DZ.IIIFor this circuit self-adapted over-current protection setting valve；For overcurrent protection safety factor, takeK_ssFor self-starting coefficient, take K_ss=1；K_reFor drop-off to pick-up radio, take 0.85-0.95；I_lineBearing in real time for this circuit Charged current；

The overcurrent protection of this circuit also should meet:

$I_{DZ.III}=K_K^{{\mathrm{III}}^{\′}}{I}_{DZ.III.2}---\left(12\right)$

In formulaFor overcurrent protection coefficient, takeI_DZ.III.2Fixed for next circuit overcurrent protection adjacent Value,

The setting valve I of overcurrent protection_DZ.IIIThe greater in modus ponens (11), (12).

Such as Fig. 3, provide a kind of self adaptation three section protection device according to self adaptation three section protection method, including voltammeter Calculate module: according to gathering the voltage x current data that current acquisition collects, obtain amplitude and the phase angle of voltage x current；

SCADA system: be responsible for the collection of signal and the arrangement of system information；

Adaptive guard module: by the setting method of self adaptation three sect current protection, SCADA system is sent joining The operation information of electric line and calculated the real-time amplitude data of the voltage x current that module is sent by voltage x current and process, meter Calculate the real-time setting valve of three section protection；

Communication module: make each module and SCADA system machine carry out communication, thus the distant place realizing information is transmitted and exchange；

And show and input module: primary system figure, measurement data, protection information, fault waveform, voltage electricity can be shown Stream calculation module, communication module and display with input module respectively with adaptive guard module communicate to connect, communication module with SCADA system communicates to connect.

As Fig. 4-5 voltage x current calculate module include analogue signal acquisition circuit, level shifting circuit, a/d converter and Dsp processor.Analogue signal acquisition circuit, level shifting circuit, a/d converter are sequentially connected with dsp processor.Wherein AD turns Parallel operation uses the dual pathways of TI company production, four tunnels, analog differential input, 16bit synchronized sampling serial A/D converter ADS8362.Analogue signal acquisition circuit includes bipolar operational amplifier IC chip and current transformer, and bipolarity is transported Calculate amplifier integrated circuit chip to be connected with Current Transmit A1.Level shifting circuit is integrated by two bipolar operational amplifier Circuit chip composes in series.In the present embodiment, bipolar operational amplifier IC chip all uses OP07 chip, and electric current is mutual Sensor uses ZMCT113C, ZMCT113C scale of precision 0.5 grade, the range of linearity 0～100A, specified input current 5A, Ke Yinai Requirement of system design is met by the rated current of 20 times.Voltage signal after transformer converts is that small-signal need to be through amplifying circuit ADS8362 is passed to after amplification.

Such as Fig. 6-9, display and input module include single-chip microcomputer, liquid crystal display screen display circuit, keyboard interface circuit and LED Display circuit.Liquid crystal display screen display circuit, keyboard interface circuit and LED display circuit are connected with single chip communication respectively.This The liquid crystal used in embodiment is Organic Light Emitting Diode i.e. OLED, has the shock resistance of excellence, flexible, low-temperature characteristics Good, manufacturing process is simple, the advantages such as cost is lower.Liquid crystal display screen uses full-localized display, can show primary system figure, measure number According to, protection information, fault waveform.Use low power operation pattern under liquid crystal display screen default situations, extend the physical life of liquid crystal. Panel button is connected with keyboard interface circuit, designs short and sweet convenient to operate, panel has the LED display lamp of correspondence, to dress The various states put show, make user very clear to the ruuning situation of Apparatus and system.

Such as Figure 10, the self adaptation three section protection device that the present embodiment provides also includes switching value input circuit.This switching value Input circuit is integrated in, with the general-purpose relay module of protection device, volume and the cost reducing device on one piece of circuit board.Open Pass amount input circuit is connected with the external apparatus interface of this device, including optocoupler, current-limiting resistance, filter unit and stabilivolt. Stabilivolt, current-limiting resistance and filter unit are connected to light emitting diode one end of optocoupler successively, and filter unit is by electric capacity and resistance Connect composition.

Communication module is integrated with 485 communication modules and GPRS communication, in that context it may be convenient to realize remote control, remote measurement, remote regulating, distant Telecommunication function, meets the needs of feed line automatization system communication flexibly.

Claims (6)

1. a self adaptation three section protection device, it is characterised in that include

Voltage x current calculates module: according to gathering the voltage x current data that current acquisition arrives, obtain amplitude and the phase of voltage x current Angle；

SCADA system: be responsible for the collection of signal and the arrangement of system information；

Adaptive guard module: SCADA system is sent the operation information of the distribution line come and is calculated mould by voltage x current The real-time amplitude data of the voltage x current that block is sent processes, and calculates the real-time setting valve of three section protection, it is achieved self adaptation Adjusting of three sect current protection；

Communication module: make each module and SCADA system machine carry out communication, thus the distant place realizing information is transmitted and exchange；

And show and input module: primary system figure, measurement data, protection information, fault waveform, described voltage electricity can be shown Stream calculation module, communication module and display and input module communicate to connect with adaptive guard module respectively, described communication mould Block communicates to connect with SCADA system；

Also including switching value input circuit, described switching value input circuit is connected with the external apparatus interface of this device, including light Coupling, current-limiting resistance, filter unit and stabilivolt, described stabilivolt, current-limiting resistance and filter unit are connected to optocoupler successively Light emitting diode one end, described filter unit is connected with resistance by electric capacity and forms, and described voltage x current calculates module and includes simulation Signal acquisition circuit, level shifting circuit, a/d converter and dsp processor, described analogue signal acquisition circuit, level conversion Circuit, a/d converter are sequentially connected with dsp processor, and described analogue signal acquisition circuit includes that bipolar operational amplifier is integrated Circuit chip and current transformer, described bipolar operational amplifier IC chip is connected with current transformer, described electricity Flat change-over circuit is composed in series by two bipolar operational amplifier IC chips.

Self adaptation three section protection device the most according to claim 1, it is characterised in that described display includes with input module Single-chip microcomputer, liquid crystal display screen display circuit, keyboard interface circuit and LED display circuit, described liquid crystal display screen display circuit, keyboard connect Mouth circuit and LED display circuit are connected with described single chip communication respectively.

3. the self adaptation three section protection device as described in any one of claim 1-2, it is provided that a kind of self adaptation three section protection method, Based on current quick, band time limit current quick and three kinds of salvos of overcurrent protection, it is characterised in that the party Method determines the calculating of the action current real-time voltage current amplitude of above-mentioned salvo, distribution line parameter and setting valve and closes System, the change of the voltage x current amplitude that described setting valve can automatically collect along with distribution line parameter and device and Changing, described self adaptation three section protection method comprises the steps,

1) the most accurately gather voltage and electric current by adaptive filter algorithm, obtain fundamental current amplitude i₁；

2) three kinds of salvos adjusted respectively obtain the setting valve of its correspondence:

Current quick is adjusted: the actual operating current according to power system and malfunction determine event in real time, online Fault type coefficient when barrier occurs and system power supply side practical impedance, and then calculate current quick setting valve I_DZ.I；

Band time limit current quick is adjusted: when next adjacent circuit uses self-adaptive current fast tripping protection, according to the time limit Quick-break current protection safety factor determines the self adaptation of this circuit with next circuit self-adaptive current fast tripping protection setting valve adjacent Current quick setting valve I_DZ.II；

Overcurrent protection is adjusted: can obtain its setting valve I according to the self-starting coefficient of this circuit and Real-time Load electric current_DZ.III, with Adapt to load and the change of the method for operation；

3)i₁>I_DZ.I, then carry out current quick measure, otherwise go to step 4)；

4) through T after a while_IIAfter, if i₁>I_DZ.II, then carry out the current quick measure of band time limit, otherwise go to step 5)；

Step 5) through T after a while_IIIAfter, if i₁>I_DZ.III, then carry out overcurrent protection measure, otherwise terminate this three section protection Method；

Described adaptive filter algorithm comprises the steps:

A) set the Fourier expansion form of input signal i (t) as:

In formula, f_nIt is the frequency of nth harmonic electric current, I_nFor the amplitude of harmonic current,For the phase angle of harmonic current, i₁T () is base Ripple electric current, i_nT () is all harmonic current sums in addition to first-harmonic；

B) formulate a digital filter input signal i (t) is filtered process, obtain filtered process after i (t) Fu in Leaf expanded form is:

x₁(t)=a₁sin(ω₁t)+b₁cos(ω₁t) (6)

In formula, n is natural number, n=0,1,2 ...；w₁It it is the angular frequency of fundamental current；a_nAnd b_nEach represent cosine term with each The sine wave period of subharmonic, a₀For direct current component value, a₁And b₁For fundamental current amplitude；

C) fundamental current amplitude i is obtained according to formula (5)-(6)₁For:

Length H=hT when the sampling period_WDuring=T, a in formula (7)₁And b₁It is represented by:

Wherein Tw is the sampling interval, and h is the number of samples a cycle, and ω=2 π f, f=50Hz are fundamental current frequency, T =1/f, h=48；

D) after gathering each sample, by i₁With protection definite value I_DZCompare, if i₁Result of calculation more than I_DZ, then enter Enter to corresponding exception handles；

In described step b), digital filter is based on following iterative formula:

C (k)=d (k)-y ' (k)=X^T(k)W^*(k)-X^T(k)W(k) (1)

E (k)=y (k)-y'(k)=d (k)+ξ (k)-y'(k)=c (k)+ξ (k) (2)

W (k+1)=W (k)+2 μ e (k) X (k) (3)

In formula (1)-(3), X (k) is the input signal in k moment, and W (k) is the weight coefficient of sef-adapting filter, and W* (k) is not Knowing the weight coefficient of system, d (k) is desired signal, y'(k) it is the output signal of sef-adapting filter, e (k) is ξ (k) and c K the error of (), ξ (k) is noise signal, and c (k) is tracking error signal, and μ is step factor, and X (k) is reference-input signal；

The described digital filter continuous iteration by formula (1) (2) (3), controls error e (k) feedback minimum, at W (k) to W* K () is revised during, make filtered output signals y'(k) it is similar to desired output d (k), to guarantee in described each salvo Voltage, the acquisition precision of electric current and speed, according to iterative formula (1)-(3), setting noise signal ξ (k) is in (t), it is desirable to letter Number d (k) is i₁(t), reference-input signal X (k) be i (t), W (k) initial value be Arbitrary Transfer Function, if t=(0,1,2 ... k), μ is beginning iteration after step factor, is fed back by error e (k), and W (k) constantly approximates to W* (k), makes y'(k) automatic tracing Change i₁T (), completes the filtering to input signal i (t).

Self adaptation three section protection method the most according to claim 3, it is characterised in that described step 2) in current quick-breaking protect The tuning formulae protected is:

In formulaFor current quick safety factor, take 1.2-1.3；E is system equivalent source phase electromotive force；Z is by protective wire Road unit length impedance；L is the distance of trouble point and protection installation place.

Self adaptation three section protection method the most according to claim 4, it is characterised in that described step 2) in the quick-break of band time limit The tuning formulae of current protection is:

In formulaBand time limit quick-break current protection safety factor, takesI_DZ.I.2For next circuit self-adaptive current adjacent Fast tripping protection setting valve.

Self adaptation three section protection method the most according to claim 3, it is characterised in that described step 2) in self adaptation the most electric The tuning formulae of stream protection is:

I in formula_DZ.IIIFor this circuit self-adapted over-current protection setting valve；For overcurrent protection safety factor, takeK_ssFor self-starting coefficient, take K_ss=1；K_reFor drop-off to pick-up radio, take 0.85-0.95；I_lineBearing in real time for this circuit Charged current；

The overcurrent protection of this circuit also should meet:

In formulaFor overcurrent protection coefficient, takeI_DZ.III.2For next circuit overcurrent protection definite value adjacent,

The setting valve I of overcurrent protection_DZ.IIIThe greater in modus ponens (11), (12).