CN106153183A - The on-line monitoring method of on-load tap changers of transformers machine performance - Google Patents

Abstract

The invention discloses the on-line monitoring method of a kind of on-load tap changers of transformers machine performance, including: gather the vibration signal on on-load tap changers of transformers surface；Vibration signal x (t) is carried out phase space reconfiguration, obtains the phase space reconstruction of vibration signal；Calculate vibration signal at bunch Center Number Kc of phase space reconstruction and the position coordinates at Kc Ge Cu center；In calculating load ratio bridging switch operating process, vibration signal reconstruction phase space ZhongKcGe Cu center is relative to the relative error at i-th bunch center.The present invention effectively, in high sensitivity on-line monitoring go out on-load tap changers of transformers running status. thus can overhaul in time or change on-load tap changers of transformers, it is to avoid load ratio bridging switch damages and causes transformer fault and electric power system fault.

Description

The on-line monitoring method of on-load tap changers of transformers machine performance

Technical field

The present invention relates to a kind of signal monitoring method, particularly relate to a kind of on-load tap changers of transformers machinery The on-line monitoring method of state.

Background technology

ULTC is one of very important key equipment in the various equipment of power system, mainly Action step by step by on-load tap changer (OLTC:On-load Tap Changer), it is achieved electric power The on-load voltage regulation of transformator, therefore, load ratio bridging switch is one of key core parts of power transformer.

Rely on load ratio bridging switch switching action accurately and timely, not only can reduce and avoid voltage significantly Degree fluctuation, and can force distribution load trend, and excavating equipment is idle and meritorious exerts oneself, increase electrical network The motility of scheduling.

Along with the raising requiring the quality of power supply, the average daily times of pressure regulation of loaded voltage-regulating electric transformer significantly increases Adding, times of pressure regulation is consequently increased, and correspondingly, causes the fault rate of load ratio bridging switch to present growth and becomes Gesture, affects the safe and stable operation of power system.

Foreign statistic data shows, load ratio bridging switch fault occupies the 41% of voltage adjustment of on-load transformer fault, several In rising trend.Domestic average statistics data show, the fault of load ratio bridging switch accounts for transformer fault More than 20%.Therefore, the running status of the load ratio bridging switch of operating power transformer is carried out online Monitoring and fault diagnosis, be found to have incipient fault hidden danger and the extent of damage of on-load shunting switch in time, research The state estimation technology of load ratio bridging switch, it is achieved the rationalization of maintenance of equipment, standardization and scientific, Meet in Intelligent transformer station about enforcement Postural Evaluations of Electric Equipments and the requirement of State Maintenance, have relatively Big Research Significance and good application prospect.

On-load tap changers of transformers is mainly made up of, including electricity selector, switching switch and motor drive mechanism Gas performance and two aspects of mechanical performance.Wherein electric property refers mainly to the contact resistance of contact, works as contact When contact resistance increases, contact can be caused overheated, even scaling loss.Mechanical performance refers to load ratio bridging switch Operating process selects sequence of movement and the time coordination of the parts such as switch and switching switch and switched Whether journey exists jam and contact switching is not in place etc..Mechanical breakdown is that power transformer loaded tap-off leaves The major failure type closed, it may damage load ratio bridging switch and power transformer, affect power equipment Run with the normal safe of system and cause serious consequence.

At present, the mostly employing off-line periodic maintenance mode of domestic load ratio bridging switch, it is each according to setting Wear law, predetermined repair type, workshop every and maintenance load equipment is carried out periodically Maintenance, prevents the generation of fault.Periodic maintenance mode can make production and repairing all can in a planned way carry out, Be possible to prevent and reduce catastrophic failure, it is adaptable to known device life distribution law and also have the obvious loss phase Equipment.Shortcoming is that workload is big, and efficiency is low and certainty of measurement is the highest, and can not find in time between maintenance Every interior equipment fault, the most do not adapt to form demand.

In operation, collision or friction between mechanism's parts can cause machinery to load ratio bridging switch Vibration, and mechanical vibration are abundant information carriers, on load ratio bridging switch switch support, shell Vibration be internal multiple phenomenon excitation response.If the primary collision of mechanism's parts or friction are called one Individual vibration event, then the mechanical oscillation signal that different time of vibration produce can form a vibration in time domain The time series of signal.Therefore, if analysis of vibration signal method to be incorporated into the online prison of load ratio bridging switch Surveying and fault diagnosis, the machinery by non-invasi ground Monitoring Power Transformer load ratio bridging switch is special Property, Real-time Collection, analyze and process the vibration signal on load ratio bridging switch surface, obtain drive mechanism Status information and mode of operation, and then the running status of on-load tap changers of transformers is identified, can It is found to have the Hidden fault in on-load shunting switch running in time, improves load ratio bridging switch, transformation Device and the reliability of Operation of Electric Systems and peace Quan Xing.

Summary of the invention

It is an object of the invention to provide the on-line monitoring side of a kind of on-load tap changers of transformers machine performance Method, the method is by monitoring in real time the vibration signal in load ratio bridging switch course of action, it is possible to Realize the judgement efficiently and accurately to on-load tap changers of transformers machine performance.

In order to realize foregoing invention purpose, the invention provides a kind of on-load tap changers of transformers mechanical-like The on-line monitoring method of state, it comprises the following steps:

1, the on-line monitoring method of a kind of on-load tap changers of transformers machine performance, it is characterised in that bag Include the following step:

(1) vibrating sensor is arranged on the surface of on-load tap changers of transformers, Real-time Collection transformator Vibration signal x (t) on load ratio bridging switch surface, t=1 ... No, No are seasonal effect in time series length；

(2) use delay coordinate method that vibration signal x (t) is carried out phase space reconfiguration, for

$\left\{\begin{array}{c}X\left(1\right)=[x\left(1\right),x(1+\mathrm{\τ}),\·\·\·,x(1+(m-1)\mathrm{\τ})]\\ X\left(2\right)=[x\left(2\right),x(2+\mathrm{\τ}),\·\·\·,x(2+(m-1)\mathrm{\τ})]\\ ......\\ X\left(k\right)=[x\left(k\right),x(k+\mathrm{\τ}),\·\·\·,x(k+(m-1)\mathrm{\τ})]\\ ......\\ X\left(N\right)=[x\left(N\right),x(N+\mathrm{\τ}),\·\·\·,x(N+(m-1)\mathrm{\τ})]\end{array}\right.$

N is the time arrow number in the phase space after phase space reconfiguration, and m is Embedded dimensions, and τ is for postponing Time, and X (k) (k=1 ..., N) for the kth of the phase space after vibration signal x (t) is reconstructed Individual time arrow, No=N+ (m-1) τ；

This N number of time arrow defines the phase space of a reconstruct, this N number of time delay sequence association Integral function is

$C_s(m,N,r,t)=\frac{2}{N(N-1)}\underset{1\≤i\≤j\≤N}{\mathrm{\Σ}}H(r-d_{\mathrm{ij}}),r>0$

d_ij=| | X (i)-X (j) | |

$H\left(r\right)=\left\{\begin{array}{cc}1,& r\&GreaterEqual;0\\ 0,& r<0\end{array}\right.$

H (r) is Heaviside jump function, and r is radius；

Postponing coordinate method is the common mathematical method that One-dimension Time Series carries out higher-dimension phase space reconfiguration, its It is that one of ordinary skilled in the art is all known, therefore is not described further.

Described Embedded dimensions m and the calculating process of delay time T are

(I) standard deviation sigma of vibration signal x (t) is calculated；

(1I) vibration signal x (t) is divided into t₀Individual disjoint subsequence, for

$\{x_1,x_{t_0+1},x_{2t_0+1},\&CenterDot;\&CenterDot;\&CenterDot;\}$

$\{x_2,x_{t_0+2},x_{2t_0+2},\&CenterDot;\&CenterDot;\&CenterDot;\}$

……

$\{x_{t_0},x_{{2t}_0},x_{{3t}_0},\&CenterDot;\&CenterDot;\&CenterDot;\}$

Herein, a length of 1=N of each subsequence₀/t₀；

(III) this t is defined₀The statistic of test of individual subsequence is Embedded dimensions t when being m₀Individual subsequence Correlation integral function and Embedded dimensions t when being I₀Putting down of the correlation integral function difference sum of subsequence Average, its computing formula is

$S(m,N_0,r,t_0)=\frac{1}{t_0}\underset{s=1}{\overset{t_0}{\mathrm{\&Sigma;}}}[C_s(m,N_0/t_0,r,t_0)-C_s^m(1,N_0/t_0,r,t_0)]$

Then work as N₀During → ∞, have

$S(m,r,t_0)=\frac{1}{t_0}\underset{s=1}{\overset{t_0}{\mathrm{\&Sigma;}}}[C_s(m,r,t_0)-C_s^m(1,r,t_0)]$

(IV) to t₀Individual subsequence, calculates: the average of statistic of test respectivelyThe difference of statistic of test ValueVariance Scor (t with statistic of test₀), its expression formula is respectively

$\stackrel{\&OverBar;}{S}\left(t_0\right)=\frac{1}{16}\underset{m=2}{\overset{5}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{4}{\mathrm{\&Sigma;}}}S(m,r_j,t_0)$

$\mathrm{\&Delta;}\stackrel{\&OverBar;}{S}\left(t_0\right)=\frac{1}{4}\underset{m=2}{\overset{5}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;S}(m,t_0)$

$S_{\mathrm{cor}}\left(t_0\right)=\mathrm{\&Delta;}\stackrel{\&OverBar;}{S}\left(t_0\right)+\left|\stackrel{\&OverBar;}{S}\left(t_0\right)\right|$

Δ S (m, t₀)=max{S (m, r_j, t₀)-min{S (m, r_j, t₀)}

In formula, r_j=j σ/2；

(IV) findFirst zero point orFirst minimum point, first zero point or The time that one minimum point is corresponding is delay time T；

(V) Scor (t is found₀) minimum point, the corresponding time is Vibration Signal Time Series x (t) First overall maximum time window τ_w. calculating Embedded dimensions m, formula is as follows:

M=int (τ_w/τ+1)

In formula, int is bracket function.

(3) the vibration signal bunch Center Number at phase space reconstruction is calculated according to K-means clustering methodology The position coordinates at Kc and Kc Ge Cu center.Described bunch Center Number Kc and the position at Kc Ge Cu center The calculating process of coordinate is

(I) optional Kc in N number of vector of phase space reconstruction₁Individual phase point, as a bunch center, takes Kc herein₁= 2, Kc₁Ge Cu center is respectively X (i) (1 ＜ i Kc in the position of phase space reconstruction₁).Calculate in phase space Remaining phase point and this Kc₁The Euclidean distance of individual phase point, is included into remaining phase point according to closest principle To this Kc₁In individual bunch.Absolute distance is the accepted value mathematical method trying to achieve 2 distances, and it is this area In those of ordinary skill all known, therefore the most no longer carry out column expression.

(II) Kc is calculated₁The average central of all phase points in individual bunch, as Kc₁Individual bunch in phase space New bunch center, be designated as X ' (i) (1 ＜ i≤Kc₁, mouth, i.e. X ' (i) are tieed up at the m τ of phase space and are sat It is designated as Kc₁The meansigma methods of the m τ dimension coordinate of all phase points in bunch.

(III) Xin Cucu center X ' (i) shift ratio relative to original Cu Cu center X (i) is calculated (BiasProportion, BP), when shift ratio is less than I%, it is believed that place-centric X ' (i) of new bunch It is stable；When shift ratio is more than 1%, it is believed that place-centric X ' (i) of new bunch is unstable, Repeat step (I), step (II) and step (1II), until obtaining Kc₁Individual new bunch of stable center. The computing formula of shift ratio is

(IV) according to the Kc determined₁Ge Xincu center X ' (i), recalculates remaining phase point in phase space Relative to Kc₁The Euclidean distance of Ge Cu center X ' (i), is included into remaining phase point according to closest principle To this Kc₁In individual bunch.

(V) Kc is calculated respectively₁The distance of Ge Cuzhongcu center and each phase point belonging to this bunch, it calculates Formula is

$J\left(C_{K_{C1}}\right)=\underset{X_i\&Element;C_{K_C}}{\mathrm{\&Sigma;}}{\left|\right|X^{,}\left(i\right)-X\left(j\right)\left|\right|}^2,1<i\&le;K_{C1},1\&le;j\&le;P_t$

X ' (i) is the phase space position at i-th Cu Cu center, 1 ＜ i≤Kc₁；X (j) is for belonging to i-th The Phase Coordinates of phase point；Pt is to belong to counting out mutually of i-th bunch.

The distance at each bunch of center with the phase point belonging to this bunch is added up, obtains the overall distance of this bunch, Its computing formula is

$J\left(C\right)=\underset{K=1}{\overset{K_{C1}}{\mathrm{\&Sigma;}}}J\left(K_{C1}\right)$

(VI) Kc=Kc is made₁+ 1, repeat step (I)～step (V), obtain the overall distance of Kc bunch, It is designated as J ' (C).Calculate the reduction speed (Decreasing Rate, DR) of overall distance, when reducing speed During less than 5%, it is believed that the reduction speed of overall distance is basicly stable, and reconstruction signal is fully represented, Now K '.It is the number at required bunch center, X ' (i) (1 ＜ i≤Kc₁) it is the position at Kc Ge Cu center Put coordinate.Otherwise repeat step (I)～step (VI), until the reduction speed of overall distance is basicly stable, Now corresponding Kc is the number at required bunch center.

The computing formula of described reduction speed is

$\mathrm{DR}=\frac{|J^{\&prime;}\left(C\right)-J\left(C\right)|}{\left|J\left(C\right)\right|}\&times;100\%$

(4) absolute distance at Kc Ge Cu center and i-th bunch center is calculated respectively.Absolute distance is to try to achieve The accepted value mathematical method of 2 distances, it is that one of ordinary skilled in the art is all known, therefore The most no longer carry out column expression；

(5) K in vibration signal reconstruction phase space is calculated in load ratio bridging switch operating process_CGe Cu center phase Relative error for the 1st Ge Cu center.If the 2nd Ge Cu center and the absolute distance at the 1st Ge Cu center It is reduced to original 20% and the 2nd Ge Cu center absolute distance with the 1st Ge Cu center more than remaining Kc-2 Ge Cu center and the absolute distance at the 1st Ge Cu center, then judge to run in load ratio bridging switch operating process Abnormal state；Otherwise it is assumed that running status is normal in load ratio bridging switch operating process.

It is to say, the technical program is by one section of vibration in on-load tap changers of transformers course of action Signal carries out phase space reconfiguration, calculates bunch Center Number of space phase point and in phase space in higher dimensional space Correspondence position, then calculate calculate before and after load ratio bridging switch action Kc Ge Cu center with in 1st bunch The absolute distance of the heart and the relative error of absolute distance, according to the relative error of absolute error Yu absolute distance Change is it may determine that the running status that goes out in on-load tap changers of transformers operating process.

The on-line monitoring method of on-load tap changers of transformers running status of the present invention is owing to have employed Technique scheme so that it can real-time by on-load tap changers of transformers surface vibration signals Monitoring, directly judges the duty of on-load tap changers of transformers, and this determination methods is efficient, accurate, And easy to implement, it is simple to operator find that the drought period mechanical breakdown of on-load tap changers of transformers is hidden in time Suffer from, thus according to abnormal conditions on-load tap changers of transformers safeguarded in time and overhaul, significantly Reduce the fault spoilage of on-load tap changers of transformers.

Accompanying drawing explanation

Fig. 1 be the on-line monitoring method of on-load tap changers of transformers machine performance of the present invention in an embodiment Vibration signal during the load ratio bridging switch action collected.

Fig. 2 is that the on-line monitoring method using on-load tap changers of transformers machine performance of the present invention is being implemented The Kc Ge Cu center obtained in example and the absolute distance curve at the 1st Ge Cu center.

Detailed description of the invention

Come on-load tap changers of transformers of the present invention machinery below in conjunction with the drawings and specific embodiments The on-line monitoring method of state is described in further detail.

With the M type load ratio bridging switch of the 35kV transformator of certain transformer station of certain Utilities Electric Co. as subjects Carry out on-line monitoring, judge the machinery in this on-load tap changers of transformers operating process according to the following step State:

(1) vibrating sensor is arranged on the surface of this on-load tap changers of transformers, Real-time Collection transformation Vibration signal x (t) on device load ratio bridging switch surface, t=1,---No, No are seasonal effect in time series length:

(2) vibration signal collected is carried out anti aliasing purposes digital filtering and cache, then by a high speed Bus transfer is to data analysis module；

(3) data analysis module carries out phase space reconfiguration by postponing coordinate method to vibration signal x (t), for

$\left\{\begin{array}{c}X\left(1\right)=[x\left(1\right),x(1+\mathrm{\&tau;}),\&CenterDot;\&CenterDot;\&CenterDot;,x(1+(m-1)\mathrm{\&tau;})]\\ X\left(2\right)=[x\left(2\right),x(2+\mathrm{\&tau;}),\&CenterDot;\&CenterDot;\&CenterDot;,x(2+(m-1)\mathrm{\&tau;})]\\ ......\\ X\left(k\right)=[x\left(k\right),x(k+\mathrm{\&tau;}),\&CenterDot;\&CenterDot;\&CenterDot;,x(k+(m-1)\mathrm{\&tau;})]\\ ......\\ X\left(N\right)=[x\left(N\right),x(N+\mathrm{\&tau;}),\&CenterDot;\&CenterDot;\&CenterDot;,x(N+(m-1)\mathrm{\&tau;})]\end{array}\right.$

N is the time arrow number in the phase space after phase space reconfiguration, and m is Embedded dimensions, and τ is for postponing Time, and X (k) (k=1 ..., N) for the kth of the phase space after vibration signal x (t) is reconstructed Individual time arrow, No=N+ (m-1) τ；

This N number of time arrow defines the phase space of a reconstruct, this N number of time delay sequence association Integral function is

$C_s(m,N,r,t)=\frac{2}{N(N-1)}\underset{1\&le;i\&le;j\&le;N}{\mathrm{\&Sigma;}}H(r-d_{\mathrm{ij}}),r>0$

d_ij=| | X (i)-X (j) | |

$H\left(r\right)=\left\{\begin{array}{cc}1,& r\&GreaterEqual;0\\ 0,& r<0\end{array}\right.$

H (r) is Heaviside jump function, and r is radius；

Described Embedded dimensions m and the calculating process of delay time T are

(I) standard deviation sigma of Vibration Signal Time Series x (t) is calculated；

(II) vibration signal x (t) is divided into t₀Individual disjoint subsequence, for

$\{x_1,x_{t_0+1},x_{2t_0+1},\&CenterDot;\&CenterDot;\&CenterDot;\}$

$\{x_2,x_{t_0+2},x_{2t_0+2},\&CenterDot;\&CenterDot;\&CenterDot;\}$

$\{x_{t_0},x_{{2t}_0},x_{{3t}_0},\&CenterDot;\&CenterDot;\&CenterDot;\}$

Herein, a length of 1=No/t of each subsequence₀, have t herein₀=6；

(III) this t is defined₀The statistic of test of individual subsequence is Embedded dimensions t when being m₀Individual subsequence Correlation integral function and Embedded dimensions t when being 1₀Putting down of the correlation integral function difference sum of subsequence Average, its computing formula is

$S(m,N_0,r,t_0)=\frac{1}{t_0}\underset{s=1}{\overset{t_0}{\mathrm{\&Sigma;}}}[C_s(m,N_0/t_0,r,t_0)-C_s^m(1,N_0/t_0,r,t_0)]$

Then as No → ∞ | have

$S(m,r,t_0)=\frac{1}{t_0}\underset{s=1}{\overset{t_0}{\mathrm{\&Sigma;}}}[C_s(m,r,t_0)-C_s^m(1,r,t_0)]$

(IV) to t₀Individual subsequence, calculates: the average of statistic of test respectively , the difference of statistic of testVariance S with statistic of test_c0r(t₀), its expression formula is respectively For

$\stackrel{\&OverBar;}{S}\left(t_0\right)=\frac{1}{16}\underset{m=2}{\overset{5}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{4}{\mathrm{\&Sigma;}}}S(m,r_j,t_0)$

$\mathrm{\&Delta;}\stackrel{\&OverBar;}{S}\left(t_0\right)=\frac{1}{4}\underset{m=2}{\overset{5}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;S}(m,t_0)$

$S_{\mathrm{cor}}\left(t_0\right)=\mathrm{\&Delta;}\stackrel{\&OverBar;}{S}\left(t_0\right)+\left|\stackrel{\&OverBar;}{S}\left(t_0\right)\right|$

Δ S (m, t₀)=max{S (m, r_j, t₀)-min{S (m, r_j, t₀)}

R_j=j σ/2；

(IV) findFirst zero point orFirst minimum point, first Individual zero point or time corresponding to first minimum point are delay time T；

(V) S is found_cor(t₀) minimum point, the corresponding time is Vibration Signal Time Series X (t) First overall maximum time window τ_w, calculating Embedded dimensions m, formula is as follows:

M=int (τ_w/T+1)

Int is bracket function.

There are m=3, τ=11 herein

(4) the vibration signal bunch Center Number at phase space reconstruction is calculated according to K-means clustering methodology The position coordinates at Kc and Kc Ge Cu center.Described bunch Center Number Kc and the position at Kc Ge Cu center The calculating process of coordinate is

(I) optional K in N number of vector of phase space reconstruction_c1Individual phase point, as a bunch center, takes K herein_c1= 2, K_c1Ge Cu center is X (i) (1 ＜ i≤K in the position of phase space reconstruction_c1).Calculate respectively in phase space Remaining phase point and this K_c1The Euclidean distance of individual phase point, is included into remaining phase point according to closest principle This K_c1In individual bunch.Absolute distance is the accepted value mathematical method trying to achieve 2 distances, in it is this area Those of ordinary skill is all known, therefore the most no longer carries out column expression.

(II) average central of all phase points in Kc bunch is calculated, as K_c1Individual bunch in phase space New bunch center, be designated as X ' (i) (1 ＜ i≤K_c1), i.e. X ' (i) ties up at the m of phase space and sits Mark K_c1The meansigma methods of the m dimension coordinate of all phase points in bunch.

(III) Xin Cucu center X ' (i) shift ratio relative to original Cu Cu center X (i) is calculated (Bias Proportion, BP), when shift ratio is less than 1%, it is believed that place-centric X ' (i) of new bunch It is stable；When shift ratio is more than 1%, it is believed that place-centric X ' (i) of new bunch is unstable, Repeat step (I), step (II) and step (1II), until obtaining K_c1Individual new bunch of stable center. The computing formula of shift ratio is

(IV) according to the K determined_c1Ge Xincu center X ' (i), recalculates remaining phase point phase in phase space For this K_c1The Euclidean distance of Ge Cu center X ' (i), returns remaining phase point according to closest principle Enter to this K_c1In individual bunch.

(V) this K is calculated respectively_c1The distance of Ge Cuzhongcu center and each phase point belonging to this bunch, it calculates Formula is

$J\left(C_{K_{C1}}\right)=\underset{X_i\&Element;C_{K_C}}{\mathrm{\&Sigma;}}{\left|\right|X^{,}\left(i\right)-X\left(j\right)\left|\right|}^2,1<i\&le;K_{C1},1\&le;j\&le;P_t$

X ' (i) is the phase space position at i-th Cu Cu center, 1 ＜ i≤K_c1, X (j) is for belonging to jth The Phase Coordinates of individual phase point: Pt is to belong to counting out mutually of i-th bunch.

The distance at each bunch of center with the phase point belonging to this bunch is added up, obtains the overall distance of this bunch, Its computing formula is

$J\left(C\right)=\underset{K=1}{\overset{K_{C1}}{\mathrm{\&Sigma;}}}J\left(K_{C1}\right)$

(VI) Kc=K is made_c1+ 1, repeat step (I)～step (V), obtain the overall distance of Kc bunch, note For J ' (C).Calculate the reduction speed (Decreasing Rate, DR) of overall distance, when reducing speed During less than 5%, it is believed that the reduction speed of overall distance is basicly stable, and reconstruction signal is fully represented, Now K ' c is the number at required bunch center, X ' (i) (1 ＜ i≤K_c1) it is the position at Kc Ge Cu center Put coordinate.Otherwise repeat step (I) step (VI), until the reduction speed of overall distance is basicly stable, Now corresponding Kc is the number at required bunch center.

The computing formula of described reduction speed is

$\mathrm{DR}=\frac{|J^{\&prime;}\left(C\right)-J\left(C\right)|}{\left|J\left(C\right)\right|}\&times;100\%$

Herein, Kc=4,

(5) absolute distance at Ge Cu center, Kc Ge Cu center and the 1st Ge Cu center is calculated respectively.Definitely away from From being the accepted value mathematical method trying to achieve 2 distances, it is that one of ordinary skilled in the art all institutes are ripe Know, therefore the most no longer carry out column expression；

(6) vibration signal reconstruction phase space ZhongKcGe Cu center phase in load ratio bridging switch operating process is calculated Relative error for the 1st Ge Cu center.If the 2nd Ge Cu center and the absolute distance at the 1st Ge Cu center It is reduced to original 20% and the 2nd Ge Cu center absolute distance with the 1st Ge Cu center more than remaining Kc-2 Ge Cu center and the absolute distance at the 1st Ge Cu center, then judge to run in load ratio bridging switch operating process Abnormal state；Otherwise it is assumed that running status is normal in load ratio bridging switch operating process.

Fig. 2 shows in the load ratio bridging switch handoff procedure obtained according to said method in the present embodiment The absolute distance curve at Kc Ge Cu center and the 1st Ge Cu center, in these two articles of curves the 2nd Ge Cu center with The absolute distance at the 1st Ge Cu center more than remaining property-2 Ge Cu center and i-th bunch center absolute away from From.Table 1 shows in the load ratio bridging switch handoff procedure obtained according to said method in the present embodiment The relative error of the absolute distance at Kc Ge Cu center and the 1st Ge Cu center, the 2nd Ge Cu center and the 1st The absolute distance at bunch center is reduced to original 23.38%, illustrates to run in load ratio bridging switch operating process Abnormal state, it is possible to the mechanical breakdowns such as spring loosens occur, needs to keep in repair in time, it is to avoid occur Significant trouble.

Table 1 is the on-line monitoring method using on-load tap changers of transformers machine performance of the present invention The relative error of the absolute distance at the Kc Ge Cu center obtained in the present embodiment and the 1st Ge Cu center.

Table 1

It should be noted that the listed above specific embodiment being only the present invention, it is clear that the invention is not restricted to Above example, has the similar change of many therewith.If those skilled in the art is public from the present invention All deformation that the content opened directly derives or associates, all should belong to protection scope of the present invention.

Claims (2)

1. the on-line monitoring method of an on-load tap changers of transformers machine performance, it is characterised in that comprise the following steps:

(1) being arranged on the surface of on-load tap changers of transformers by vibrating sensor, Real-time Collection transformator loaded tap-off is opened Vibration signal x (t) on surface, pass, t=1 ... .No, No are seasonal effect in time series length；

(2) use delay coordinate method that vibration signal x (t) is carried out phase space reconfiguration, for

$\left\{\begin{array}{c}X\left(1\right)=[x\left(1\right),x(1+\mathrm{\&tau;}),...x(1+(m-1)\mathrm{\&tau;})]\\ X\left(2\right)=[x\left(2\right),x(2+\mathrm{\&tau;}),...,x(2+(m-1)\mathrm{\&tau;})]\\ ......\\ X\left(k\right)=[x\left(k\right),x(k+\mathrm{\&tau;}),...,x(k+(m-1)\mathrm{\&tau;})]\\ ......\\ X\left(N\right)=[x\left(N\right),x(N+\mathrm{\&tau;}),...,x(N+(m-1)\mathrm{\&tau;})]\end{array}\right.$

In formula, N is the time arrow number in the phase space after phase space reconfiguration, and m is Embedded dimensions, when T is for postponing Between, X (k) (k=1 ..., N) for the kth time arrow of the phase space after vibration signal x (t) is reconstructed, No =N+ (m-1) τ；

This N number of time arrow defines the phase space of a reconstruct, and this, correlation integral function of sequence was N number of time delay

$C_s(m,N,r,t)=\frac{2}{N(N-1)}\underset{1\&le;i\&le;j\&le;N}{\mathrm{\&Sigma;}}H(r-d_{\mathrm{ij}}),r>0$

d_ij=| | X (i)-X (j) | |

$H\left(r\right)=\left\{\begin{array}{cc}1,& r\&GreaterEqual;0\\ 0,& r<0\end{array}\right.$

In formula, H (r) is Heaviside jump function, and r is radius；

Described Embedded dimensions m and the calculating process of delay time T be:

(I) standard deviation sigma of calculating vibration signal x (t):

(II) vibration signal x (t) is divided into t0 disjoint subsequence, for

$\{x_1,x_{t_0+1},x_{{2t}_0+1},...\}$

$\{x_2,x_{t_0+2},x_{{2t}_0+2},...\}$

……

$\{x_{t_0},x_{{2t}_0},x_{{3t}_0},...\}$

Herein, a length of 1=No/t of each subsequence_o；

(III) defining the statistic of test of this t subsequence is Embedded dimensions t when being m₀The correlation integral of individual subsequence T when function and Embedded dimensions are 1_oThe meansigma methods of the correlation integral function difference sum of subsequence, its computing formula is

$S(m,N_0,r,t_0)=\frac{1}{t_0}\underset{s=1}{\overset{t_0}{\mathrm{\&Sigma;}}}[C_s(m,N_0/t_0,r{,t}_0)-C_s^m(1,N_0/t_0,r{,t}_0)]$

Then work as N₀During → ∞, have

$S(m,r,t_0)=\frac{1}{t_0}\underset{s=1}{\overset{t_0}{\mathrm{\&Sigma;}}}[C_s(m,r,t_0)-C_s^m(1,r,t_0)]$

(IV) to t_oIndividual subsequence, calculates: the average of statistic of test respectivelyThe difference of statistic of test ValueVariance S with statistic of test_c0r(t_o) its expression formula is respectively

$\stackrel{\&OverBar;}{S}\left(t_0\right)=\frac{1}{16}\underset{m=2}{\overset{5}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{4}{\mathrm{\&Sigma;}}}S(m,r_j,t_0)$

$\mathrm{\&Delta;}\stackrel{\&OverBar;}{S}\left(t_0\right)=\frac{1}{4}\underset{m=2}{\overset{5}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;S}(m,t_0)$

$S_{\mathrm{cor}}\left(t_0\right)=\mathrm{\&Delta;}\stackrel{\&OverBar;}{S}\left(t_0\right)+\left|\stackrel{\&OverBar;}{S}\left(t_0\right)\right|$

Δ S (m, t₀)=max{S (m, r_j, t₀)-min{S (m, r_j, t₀)}

In formula, r_j=j σ/2；

(IV) findFirst zero point orFirst minimum point, first zero point or first The time that individual minimum point is corresponding is delay time T

(V) S is found_c0r(t_o) minimum point, time is Vibration Signal Time Series X (t) first corresponding entirety is It is worth greatly time windowCalculating Embedded dimensions m, formula is as follows:

In formula, int is bracket function.

(3) vibration signal is calculated at bunch Center Number Pang Jigecu center of phase space reconstruction according to K-means clustering methodology Position coordinates；

(4) absolute distance at each bunch of center and the 1st Ge Cu center is calculated respectively:

(5) each bunch of center relative error relative to i-th bunch center is calculated: if the 2nd Ge Cu center and the 1st Ge Cu center Absolute distance be reduced to original 20% and the 2nd Ge Cu center absolute distance with the 1st Ge Cu center more than remaining Kc-2 Ge Cu center and the absolute distance at i-th bunch center, then judge that in load ratio bridging switch operating process, running status is abnormal；No Then, it is believed that in load ratio bridging switch operating process, running status is normal.

The on-line monitoring method of on-load tap changers of transformers machine performance the most according to claim 1, its feature exists In, described bunch Center Number Kc and the circular of the position coordinates at each bunch of center are as follows:

(I) optional Kc in N number of vector of phase space reconstruction₁Individual phase point as a bunch center, this Kc₁Ge Cu center is in reconstruct phase The position in space is X (i) (1 ＜ i ＜ Kc1), calculates remaining phase point and this Kc in phase space respectively₁The Euclidean of individual phase point away from From, according to closest principle, remaining phase point is included into this Kc₁In individual bunch；

(II) this Kc is calculated₁The average central of all phase points in bunch, as this Kc₁Individual bunch new bunch of phase space Center, is designated as X ' (i) (1 ＜ i ＜ Kc₁), i.e. X ' (i) is respectively at the m dimension coordinate of phase space with Kc₁Institute in bunch There is the meansigma methods of the m dimension coordinate of phase point；

(III) calculating Xin Cucu center X ' (i) shift ratio BP relative to original Cu Cu center X (i), formula is such as Under

When shift ratio is less than 1%, it is believed that place-centric X ' (i) of new bunch is stable, enter step (IV)；

When shift ratio is more than 1%, it is believed that place-centric X ' (i) of new bunch is unstable, return step (I)；

(IV) according to the Kc determined₁Ge Xincu center X ' (i), recalculates in phase space remaining phase point relative to this Kc₁Individual The Euclidean distance at bunch center X ' (i), is included into this Kc according to closest principle by remaining phase point₁In individual bunch.

(V) this Kc is calculated respectively₁The distance of each bunch of center and each phase point belonging to this bunch in individual bunch, its computing formula is

$J\left(C_{K_{C1}}\right)=\underset{X_i\&Element;C_{K_C}}{\mathrm{\&Sigma;}}{\left|\right|X^{\&prime;}\left(i\right)-X\left(j\right)\left|\right|}^{2}1<i\&le;K_{C1}1\&le;j\&le;P_t$

In formula, X ' (i) is the phase space position at i-th Cu Cu center, 1 ＜ i≤Kc₁；X (j) is for belong to i-th bunch The Phase Coordinates of jth phase point；P_tFor belonging to counting out mutually of i-th bunch.

The distance at each bunch of center with the phase point belonging to this bunch being added up, obtain the overall distance of this bunch, it calculates public affairs Formula is

$J\left(C\right)=\underset{K=1}{\overset{K_{C1}}{\mathrm{\&Sigma;}}}J\left(K_{C1}\right)$

(VI) Kc=Kc is made₁+ 1, repeat step (I)～step (V), obtain the overall distance of Kc bunch, be designated as J ' (C)；

Calculating reduction speed DR of overall distance, formula is

$\mathrm{DR}=\frac{|J^{\&prime;}\left(C\right)-J\left(C\right)|}{\left|J\left(C\right)\right|}\&times;100\%$

When reducing speed less than 5%, it is believed that the reduction speed of overall distance is basicly stable, and reconstruction signal is by abundant table Showing, now K ' c is the number at required bunch center, X ' (i) (1 ＜ i≤Kc₁) it is the position coordinates at Kc Ge Cu center； Otherwise repeating step (I)～step (VI), until the reduction speed of overall distance is basicly stable, now corresponding Kc is institute The number at Qiu Cu center.