CN104237703B - Band shunt reactor circuit three-phase self adaptation reclosing nature of trouble recognition methods - Google Patents

Abstract

The present invention relates to a kind of band shunt reactor circuit three-phase self adaptation reclosing nature of trouble recognition methods.Existing nature of trouble criterion range of application is different, affected many factors.The single-ended shunt reactor magnitude of current after the tripping operation of the present invention first sampling three-phase, obtains the differential-mode component of correspondence by phase-model transformation.Secondly differential-mode component frequency (cycle) is gone out according to route parameter calculation.Finally the differential-mode current instantaneous value in the differential-mode component cycle is carried out waveform analysis.In addition, during owing to there is permanent fault, differential-mode current only exists attenuating dc component, and when there is transient fault, after fault blow-out, differential-mode current only exists declining periodic component, utilizes differential-mode current wave character under the conditions of different faults character can propose a kind of new criterion of phase-to phase fault property identification be applicable to three-phase self adaptation reclosing, and differentiate the blow-out moment.The impacted factor of property judgment of the present invention is few, highly sensitive.

Description

Band shunt reactor circuit three-phase self adaptation reclosing nature of trouble recognition methods

Technical field

The invention belongs to technical field of power systems, be specifically related to a kind of band shunt reactor circuit three Phase self adaptation reclosing nature of trouble recognition methods.

Background technology

The most both at home and abroad transmission line of electricity the most all uses automatic reclosing technology, to ensureing electric power System stable operation plays vital effect.But, automatic reclosing is imitated bringing tremendous economic While benefit, also bring negative impact to power system.Because the nature of trouble of transmission line of electricity divides For transient fault and permanent fault, if coinciding with in permanent fault, be equivalent to power equipment Again impacted by fault current, the life-span of power equipment can be shortened.In order to reduce power system Loss, judged that before reclosing nature of trouble seems most important.

At present, correlational study is concentrated mainly on single-phase adaptive reclosing aspect.Although phase-to phase fault exists In short trouble, proportion is less, but coincides with heterogeneous permanent fault and stably transport security of system It is even more serious that the hazard ratio that row and electrical equipment are brought coincides with single-phase permanent fault, therefore three-phase Self adaptation reclosing has the biggest researching value.Extractible information in circuit after tripping due to three-phase Seldom, the research difficulty of three-phase self adaptation reclosing is relatively big, but still achieves certain achievement, main Have: the method 1. recovering voltage based on circuit, the discrimination precision of the method relies on to a great extent In the certainty of measurement of line side voltage transformer, and a lot of circuit be unkitted in line side voltage transformer or Only it is equiped with a phase voltage transformer；2. method based on carrier protection channel, need to rely on high frequency The passage of protection, and to not including that the phase-to phase fault processing phase exists the possibility judged by accident；3. based on fuzzy The method of neutral net, the method needs substantial amounts of training sample, and its reliability has to be tested；4. base In the method for shunt reactor electric current, including: discrimination method based on inductance capacitance parameter, but calculate Process relates to integral calculus computing, can bring bigger error when making approximate processing；Based on Model Identification With the method for current differential, when transition resistance is bigger, differentiation result is affected the biggest；Based on freedom The method that oscillating component frequency amplitude separates, needs the highest sample rate, and discrimination is relatively low；Above-mentioned Method based on shunt reactor electric current is both needed to use both-end parallel reactance when both-end band shunt reactor The device magnitude of current.

Summary of the invention

Present invention aims to the deficiencies in the prior art, it is provided that a kind of poor based on shunt reactor The three-phase self adaptation reclosing permanent fault recognition methods of mould Current Waveform Characteristics.

First the present invention samples and obtains the shunt reactor magnitude of current after three-phase tripping operation, obtains through phase-model transformation To corresponding differential-mode component, then go out differential-mode component frequency (cycle) according to route parameter calculation, Afterwards the differential-mode current instantaneous value in the differential-mode component cycle is carried out waveform analysis.If differential-mode current In only exist declining periodic component, transient fault can be judged to, be the most i.e. judged to the blow-out moment, After certain time delay, carrying out reclosing operation, if only existing attenuating dc component, being then judged to Permanent fault, thus lock-reclosing brake gear.

Further, utilize nature of trouble and transient fault blow-out time that the present invention judges, Self adaptation reclosing scheme can be implemented.Specifically: be transient fault if determining fault and put out The arc moment, then put into reclosing；If the permanent fault of being determined as, the most misaligned.

The inventive method comprises the following steps:

Step (1): sampling obtains m end shunt reactor magnitude of current i_mxa、i_mxb、i_mxc, by phase mould Convert and obtain corresponding differential-mode current component:

$\left\{\begin{array}{c}{i}_{\mathrm{mx\α}}=i_{\mathrm{mxa}}-i_{\mathrm{mxb}}\\ i_{\mathrm{mx\β}}=i_{\mathrm{mxa}}-i_{\mathrm{mxc}}\\ i_{\mathrm{mx\γ}}=i_{\mathrm{mxb}}-i_{\mathrm{mxc}}\end{array}\right.$

Step (2): go out differential-mode component frequency (cycle) according to route parameter calculation, it is assumed that occur instantaneous Property fault, as a example by single-ended band shunt reactor model, equivalent model T-shaped to circuit use complex frequency domain Analyzing, ignore line impedance, can obtain the bus admittance matrix under complex frequency domain is:

$Y\left(s\right)=\left[\begin{array}{ccc}{Y}_s& {-Y}_m& {-Y}_m\\ {-Y}_m& Y_s& {-Y}_m\\ {-Y}_m& {-Y}_m& Y_s\end{array}\right]$

$\left\{\begin{array}{c}{Y}_s=s(C_0+{2C}_m)+1/{\mathrm{sL}}_0+2/{\mathrm{sL}}_m\\ Y_m=s{C}_m+1/{\mathrm{sL}}_m\end{array}\right.$

Wherein, Ys is self-admittance, and Ym is alternate transadmittance, and C0 is line mutual-ground capacitor, and Cm is Capacitive coupling, Lm and L0 is respectively shunt reactor inductance L1 and small reactor on neutral point inductance Ln etc. Alternate inductance after effect and over the ground inductance.

The differential mode bus admittance matrix under complex frequency domain can be obtained by phase-model transformation:

$Y_{\mathrm{\α\β\γ}}\left(s\right)=(\frac{1}{L_{0}s}+\frac{3}{L_{m}s}+{3C}_{m}s+C_{0}s)\·E_{3\×3}$

By solving characteristic equation det (Y_αβγ(s))=0 can obtain differential-mode component frequency:

$f_D=\frac{1}{2\mathrm{\π}}\sqrt{\frac{L_m+{3L}_0}{L_m{L}_0(C_0+{3C}_m)}}=\frac{1}{2\mathrm{\π}}\sqrt{\frac{1}{C_1{L}_1}}$

Wherein, C1 is positive sequence electric capacity, and L1 is shunt reactor inductance.

In like manner, for both-end band shunt reactor model, bus admittance matrix is:

$Y\left(s\right)=\left[\begin{array}{ccc}{Y}_s& {-Y}_m& {-Y}_m\\ {-Y}_m& Y_s& {-Y}_m\\ {-Y}_m& {-Y}_m& Y_s\end{array}\right]$

$\left\{\begin{array}{c}{Y}_s=s(C_0+{2C}_m)+2/{\mathrm{sL}}_0+4/{\mathrm{sL}}_m\\ Y_m=s{C}_m+2/{\mathrm{sL}}_m\end{array}\right.$

By obtaining differential mode bus admittance matrix after phase-model transformation:

$Y_{\mathrm{\α\β\γ}}\left(s\right)=(\frac{2}{L_{0}s}+\frac{6}{L_{m}s}+{3C}_{m}s+C_{0}s)\·E_{3\×3}$

Solve characteristic equation det (Y_αβγ(s))=0 obtain differential-mode component frequency:

$f_D=\frac{1}{2\mathrm{\π}}\sqrt{\frac{2(L_m+{3L}_0)}{L_m{L}_0(C_0+{3C}_m)}}=\frac{1}{2\mathrm{\π}}\sqrt{\frac{2}{C_1{L}_1}}$

In sum, the differential-mode component cycle can be obtained

Step (3): the differential-mode current instantaneous value in the differential-mode component cycle is carried out waveform analysis, sentences According to for:

$\mathrm{\λ}=\frac{\left|\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{x}_i\right|}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\left|x_i\right|}>0.5$

Wherein, n is the sampling number in each data window, is taken as T_D(T_DFor the differential-mode component cycle) in Sampling number, x_iFor the differential-mode current sampled value of ith sample point in data window.

In view of when there is permanent fault, differential-mode current only exists attenuating dc component, now criterion All the time set up, and when there is transient fault, after fault blow-out, differential-mode current only exists and declines Subtracting periodic component, above-mentioned criterion is false, and utilizes differential-mode current ripple under the conditions of different faults character Shape feature can propose a kind of newly the sentencing of phase-to phase fault property identification be applicable to three-phase self adaptation reclosing According to, and differentiate the blow-out moment.When being judged to transient fault, after certain time delay, carry out weight Closing operation, when being judged to permanent fault, then lock-reclosing brake gear.

The present invention makes full use of the fault signature under different faults character, during in view of generation permanent fault, Differential-mode current only exists attenuating dc component, and when there is transient fault, after fault blow-out, Differential-mode current only exists declining periodic component, nature of trouble can be identified accordingly easily.The present invention There is applied range, it is judged that highly sensitive, not by abort situation, transition resistance, sample frequency, The advantages such as load current, fault moment, tripping operation moment, trouble point blow-out moment impact, and fit simultaneously For single-ended and both-end band shunt reactor transmission line of electricity.

Detailed description of the invention

Zhejiang University's relay protection experimental room finds when analyzing biphase or three-phase fault, of different nature Fault has different fault signatures.Can first sample and obtain single-ended shunt reactor electricity after three-phase tripping operation Flow, obtains the differential-mode component of correspondence, then goes out differential mode according to route parameter calculation through phase-model transformation Component frequencies (cycle), finally carries out ripple to the differential-mode current instantaneous value in the differential-mode component cycle Conformal analysis.During owing to permanent fault occurring, differential-mode current only exists attenuating dc component, and sends out During raw transient fault, after fault blow-out, differential-mode current only exists declining periodic component, profit One can be proposed with differential-mode current wave character under the conditions of different faults character and be applicable to three-phase certainly Adapt to the new criterion of phase-to phase fault property identification in reclosing, and differentiate the blow-out moment, the tool of the method Body step is as follows:

Step (1): sampling obtains m end shunt reactor magnitude of current i_mxa、i_mxb、i_mxc, by phase mould Conversion obtains the differential-mode current component of correspondence

$\left\{\begin{array}{c}{i}_{\mathrm{mx\α}}=i_{\mathrm{mxa}}-i_{\mathrm{mxb}}\\ i_{\mathrm{mx\β}}=i_{\mathrm{mxa}}-i_{\mathrm{mxc}}\\ i_{\mathrm{mx\γ}}=i_{\mathrm{mxb}}-i_{\mathrm{mxc}}\end{array}\right.$

Step (2): go out differential-mode component frequency (cycle), single-ended band parallel connection electricity according to route parameter calculation During anti-device it is:

$f_D=\frac{1}{2\mathrm{\π}}\sqrt{\frac{L_m+{3L}_0}{L_m{L}_0(C_0+{3C}_m)}}=\frac{1}{2\mathrm{\π}}\sqrt{\frac{1}{C_1{L}_1}}$

Wherein C₁For positive sequence electric capacity, L₁For shunt reactor inductance.

During both-end band shunt reactor it is:

$f_D=\frac{1}{2\mathrm{\π}}\sqrt{\frac{2(L_m+{3L}_0)}{L_m{L}_0(C_0+{3C}_m)}}=\frac{1}{2\mathrm{\π}}\sqrt{\frac{2}{C_1{L}_1}}$

Such that it is able to obtain the differential-mode component cycle

Step (3): the differential-mode current instantaneous value in the differential-mode component cycle is carried out waveform analysis, Criterion is:

$\mathrm{\λ}=\frac{\left|\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{x}_i\right|}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\left|x_i\right|}>0.5$

Wherein, n is the sampling number in each data window, is taken as T_D(T_DFor the differential-mode component cycle) in Sampling number, x_iFor the differential-mode current sampled value of ith sample point in data window).Permanent in view of occurring During property fault, only existing attenuating dc component in differential-mode current, now criterion is set up all the time, and occurs During transient fault, after fault blow-out, differential-mode current only exists declining periodic component, above-mentioned Criterion is false, and utilizes differential-mode current wave character under the conditions of different faults character can propose one Plant the new criterion of phase-to phase fault property identification be applicable to three-phase self adaptation reclosing, and when differentiating blow-out Carve.When being judged to transient fault, after certain time delay, carry out reclosing operation, work as judgement During for permanent fault, then lock-reclosing brake gear.

The present invention only need to utilize single-ended shunt reactor electric current to realize, and property judgment is impacted Factor is few, highly sensitive.

Claims (2)

1. band shunt reactor circuit three-phase self adaptation reclosing nature of trouble recognition methods, it is characterised in that: After transmission line of electricity generation phase-to phase fault makes the chopper three-phase tripping operation of circuit both sides, execution following steps:

Step (1): sampling obtains m end shunt reactor magnitude of current i_mxa、i_mxb、i_mxc, pass through phase-model transformation Obtain correspondence differential-mode current component:

$\left\{\begin{array}{c}{i}_{mx\mathrm{\α}}=i_{mxa}-i_{mxb}\\ i_{mx\mathrm{\β}}=i_{mxa}-i_{mxc}\\ i_{mx\mathrm{\γ}}=i_{mxb}-i_{mxc}\end{array}\right.$

Step (2): go out the differential-mode component cycle according to route parameter calculation, it is assumed that transient fault occurs is right In single-ended band shunt reactor model, equivalent model T-shaped to circuit uses complex frequency domain analysis, ignores circuit Impedance, obtaining the bus admittance matrix under complex frequency domain is:

$Y\left(s\right)=\left[\begin{array}{ccc}{Y}_s& -Y_m& -Y_m\\ -Y_m& Y_s& -Y_m\\ -Y_m& -Y_m& Y_s\end{array}\right]$

$\left\{\begin{array}{c}{Y}_s=s(C_0+2C_m)+1/{\mathrm{sL}}_0+2/{\mathrm{sL}}_m\\ Y_m={\mathrm{sC}}_m+1/{\mathrm{sL}}_m\end{array}\right.$

Wherein, Y_sFor self-admittance, Y_mFor alternate transadmittance, C₀For line mutual-ground capacitor, C_mFor alternate electricity Hold, L_mAnd L₀It is respectively shunt reactor inductance L₁And small reactor on neutral point inductance L_nAlternate after equivalence Inductance and over the ground inductance；

The differential mode bus admittance matrix under complex frequency domain is obtained by phase-model transformation:

$Y_{\mathrm{\α}\mathrm{\β}\mathrm{\γ}}\left(s\right)=(\frac{1}{L_{0}s}+\frac{3}{L_{m}s}+3C_{m}s+C_{0}s)\·E_{3\×3};$

By solving characteristic equation det (Y_αβγ(s))=0 obtain differential-mode component frequency:

$f_D=\frac{1}{2\mathrm{\π}}\sqrt{\frac{L_m+3L_0}{L_m{L}_0(C_0+3C_m)}}=\frac{1}{2\mathrm{\π}}\sqrt{\frac{1}{C_1{L}_1}};$

Wherein, C₁It is positive sequence electric capacity, L₁It is shunt reactor inductance；

In like manner, for both-end band shunt reactor model, bus admittance matrix is:

$Y\left(s\right)=\left[\begin{array}{ccc}{Y}_s& -Y_m& -Y_m\\ -Y_m& Y_s& -Y_m\\ -Y_m& -Y_m& Y_s\end{array}\right]$

$\left\{\begin{array}{c}{Y}_s=s(C_0+2C_m)+2/{\mathrm{sL}}_0+4/{\mathrm{sL}}_m\\ Y_m={\mathrm{sC}}_m+2/{\mathrm{sL}}_m\end{array}\right.$

By obtaining differential mode bus admittance matrix after phase-model transformation:

$Y_{\mathrm{\α}\mathrm{\β}\mathrm{\γ}}\left(s\right)=(\frac{2}{L_{0}s}+\frac{6}{L_{m}s}+3C_{m}s+C_{0}s)\·E_{3\×3};$

Solve characteristic equation det (Y_αβγ(s))=0 obtain differential-mode component frequency:

$f_D=\frac{1}{2\mathrm{\π}}\sqrt{\frac{2(L_m+3L_0)}{L_m{L}_0(C_0+3C_m)}}=\frac{1}{2\mathrm{\π}}\sqrt{\frac{2}{C_1{L}_1}};$

In sum, the differential-mode component cycle is obtained

Step (3): the differential-mode current instantaneous value in the differential-mode component cycle is carried out waveform analysis, criterion For:

$\mathrm{\λ}=\frac{\left|\underset{i=1}{\overset{n}{\Σ}}{x}_i\right|}{\underset{i=1}{\overset{n}{\Σ}}\left|x_i\right|}>0.5$

Wherein, n is the sampling number in each data window, is taken as differential-mode component cycle T_DInterior sampling number, x_iFor the differential-mode current sampled value of ith sample point in data window；

In view of, when there is permanent fault, only existing attenuating dc component in differential-mode current, now criterion begins Set up eventually, and when there is transient fault, after fault blow-out, differential-mode current only exists decay week Phase component, above-mentioned criterion is false, and utilizes differential-mode current wave character under the conditions of different faults character Propose a kind of new criterion of phase-to phase fault property identification be applicable to three-phase self adaptation reclosing, and differentiate to put out In the arc moment, when being judged to transient fault, after certain time delay, carry out reclosing operation, when sentencing When being set to permanent fault, then lock-reclosing brake gear.

Band shunt reactor circuit three-phase self adaptation reclosing nature of trouble the most according to claim 1 Recognition methods, it is characterised in that: utilize the method to constitute three-phase self adaptation reclosing scheme, according to fault Character judged result decides whether to carry out reclosing, i.e. if it is determined that transient fault, then puts into coincidence Lock；If it is determined that permanent fault, then misaligned after the tripping of circuit two ends.