CN103048036B - A kind of on-line monitoring method of on-load tap changers of transformers running status - Google Patents

Abstract

The on-line monitoring method of a kind of on-load tap changers of transformers running status, belongs to signal monitoring field.The mechanical oscillation signal of its Real-time Collection transformer box wall；Use delay coordinate method that vibration signal x (t) is carried out phase space reconfiguration；Determine the appointment region V of phase space reconstruction；Calculate the Density Distribution of space phase point；Calculate the correlation coefficient ρ of spatial density curve before and after load ratio bridging switch action；If correlation coefficient ρ > 0.8, then judge that load ratio bridging switch running status is normal；If correlation coefficient ρ < 0.8, then judge that load ratio bridging switch running status is abnormal.It is by carrying out monitor in real time to 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 duty.Can be widely used for the on-line monitoring of various on-load tap changers of transformers and fault diagnosis field.

Description

A kind of on-line monitoring method of on-load tap changers of transformers running status

Technical field

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

Background technology

ULTC be extremely important in the various equipment of power system and one of key equipment, it is mainly through the action step by step of on-load tap changer (OLTC:On-loadTapChanger), realize the on-load voltage regulation of power transformer, therefore, load ratio bridging switch is one of key core parts of power transformer.

Relying on load ratio bridging switch switching action accurately and timely, not only can reduce and avoid fluctuating widely of voltage, and can force distribution load trend, excavating equipment is idle and meritorious exerts oneself, the motility of increase dispatching of power netwoks.

Along with the raising that the quality of power supply is required, the average daily times of pressure regulation of power transformer dramatically increases, and times of pressure regulation increases therewith, correspondingly, causes that the fault rate of load ratio bridging switch presents growth trend, affects the safe and stable operation of power system.

Foreign statistic data shows, OLTC fault occupies the 41% of voltage adjustment of on-load transformer fault, and in rising trend.Domestic average statistics data show, the fault of OLTC accounts for more than the 20% of transformer fault.Therefore, the running status of the load ratio bridging switch of operating power transformer is carried out on-line monitoring and fault diagonosing, find incipient fault hidden danger and the extent of damage of load ratio bridging switch in time, the Condition Monitoring Technology of research load ratio bridging switch is to realize the rationalization of maintenance of equipment, standardization and scientific, meet intelligent grid about the requirement that electrical equipment is implemented State Maintenance and state estimation, there is bigger Research Significance and good application prospect.

On-load tap changers of transformers is mainly made up of selector, switching switch and motor drive mechanism, and its performance includes electric property and two aspects of mechanical performance.

The electric property of on-load tap changers of transformers refers mainly to contact resistance, when contact resistance increases, contact can be caused overheated, even scaling loss.

The mechanical performance of on-load tap changers of transformers refers to the sequence of movement and time coordination that select switch and the switching parts such as switch in OLTC operating process, and whether there is jam in handoff procedure and contact switching is not in place etc..Mechanical breakdown is the major failure type of power transformer load tap changer, and it is likely to damage load ratio bridging switch and power transformer, and the normal safe affecting power equipment and system runs and causes serious consequence.

At present, the mostly employing off-line periodic maintenance mode of domestic load ratio bridging switch, it is the wear law according to equipment, pre-determine repair type, workshop every and maintenance load equipment is carried out periodic maintenance, it is prevented that the generation of fault.

Periodic maintenance mode can make production and repairing all can in a planned way carry out, it is possible to prevents and reduces catastrophic failure, it is adaptable to known device life distribution law and also have the equipment of obvious loss phase.Shortcoming is that workload is big, and efficiency is low and certainty of measurement is not high, does not adapt to form demand gradually.

Summary of the invention

The technical problem to be solved is to provide the on-line monitoring method of a kind of on-load tap changers of transformers running status, the method is by carrying out monitor in real time to 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 duty.

The technical scheme is that the on-line monitoring method of a kind of on-load tap changers of transformers running status, including the vibration signal gathering on-load tap changers of transformers surface, delay coordinate method is used vibration signal x (t) to carry out phase space reconfiguration and determines the appointment region V of phase space reconstruction, it is characterised in that described on-line monitoring method comprises the following steps:

(1) vibration signal collected is carried out anti aliasing purposes digital filtering and high-speed cache, then pass through high-speed bus and transmit to data analysis module；

(2) postpone after vibration signal x (t) carries out phase space reconfiguration and determine the appointment region V of phase space reconstruction by coordinate method, to calculate the Density Distribution of space phase point using；

(3) correlation coefficient ρ of spatial density curve before and after load ratio bridging switch action is calculated；If correlation coefficient ρ > 0.8, then judge that load ratio bridging switch running status is normal；If correlation coefficient ρ < 0.8, then judge that load ratio bridging switch running status is abnormal；

Wherein, the calculating process of its described Embedded dimensions m and delay time T is:

(2-1) standard deviation sigma of Vibration Signal Time Series x (t) is calculated；

(2-2) Vibration Signal Time Series x (t) is divided into t disjoint subsequence, and the length l of each subsequence is l=N/t, has t=6 herein；

(2-3) to each subsequence, three statistics are calculatedAnd S_cor(t), for

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

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

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

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

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

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

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

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

In formula, r is radius, and its span is 1～4；

(2-4) findFirst zero point orFirst minimum point, first zero point or time corresponding to first minimum point are delay time T；

(2-5) S is found_corThe minimum point of (t), time is Vibration Signal Time Series x (t) first corresponding overall maximum time window τ_w, calculate Embedded dimensions m, for

M=int (τ_w/τ+1)

In formula, int is bracket function；

The calculating process of its described space phase point Density Distribution is:

Divide at equal intervals and calculate space [2R_a,3R_a], it is divided into 5 parts at equal intervals herein；

Calculating the Euclidean distance of each phase point distance initial point of phase space reconstruction, statistics phase point drops on counting of each space, obtains the phase point distribution density of each defined basis；

The computing formula of its described correlation coefficient ρ is:

$\mathrm{\&rho;}=\frac{\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}(X_i-\stackrel{\&OverBar;}{X})(Y_i-\stackrel{\&OverBar;}{Y})}{\sqrt{\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{(X_i-\stackrel{\&OverBar;}{X})}^2}\sqrt{\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{(Y_i-\stackrel{\&OverBar;}{Y})}^2}}.$

Further, described on-line monitoring method utilizes vibration acceleration sensor, the mechanical property of non-invasi ground Monitoring Power Transformer load ratio bridging switch, Real-time Collection, analyze and process the vibration signal on load ratio bridging switch surface, obtain status information and the mode of operation of drive mechanism, one section of vibration signal in on-load tap changers of transformers course of action is carried out phase space reconfiguration, space phase point Density Distribution in appointment region is calculated in higher dimensional space, then the correlation coefficient of space phase point density profile before and after load ratio bridging switch action is calculated, change according to correlation coefficient is it may determine that go out the running status of on-load tap changers of transformers, accordingly the running status of on-load tap changers of transformers is identified, the Hidden fault in load ratio bridging switch running can be found in time, improve load ratio bridging switch, the reliability of transformator and Operation of Electric Systems and safety.

The vibration signal on its described on-load tap changers of transformers surface is obtained by the vibration acceleration sensor being pasted onto surface, is not directly electrically connected with whole power system, and properly functioning for whole electrical system does not have any impact.

Compared with the prior art, the invention have the advantage that

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, make it can pass through the monitor in real time to on-load tap changers of transformers surface vibration signals, directly judge the duty of on-load tap changers of transformers, this determination methods is efficiently, accurately, and it is easy to implement, it is easy to operator and finds the exception of on-load tap changers of transformers in time, thus on-load tap changers of transformers being overhauled in time according to abnormal conditions, greatly 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 duty of the present invention collect in one embodiment load ratio bridging switch action time vibration signal.

Fig. 2 is that the phase point spatial density adopting the on-line monitoring method of on-load tap changers of transformers duty of the present invention to obtain in the present embodiment is specifying interval density profile.

Fig. 3 is the block diagram of the on-line monitoring method of on-load tap changers of transformers duty of the present invention.

Detailed description of the invention

Below in conjunction with accompanying drawing, the present invention will be further described.

Carry out on-line monitoring with the M type load ratio bridging switch of the 35kV transformator of certain transformer station of certain Utilities Electric Co. for subjects, judge the duty of this on-load tap changers of transformers according to the following step:

(1) being arranged on the surface of this on-load tap changers of transformers by vibrating sensor, the vibration signal of Real-time Collection transformer box wall, vibration signal during measured load ratio bridging switch action is as shown in Figure 1；

(2) vibration signal collected is carried out anti aliasing purposes digital filtering and high-speed cache, then pass through high-speed bus and transmit to data analysis module；

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

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

In formula, N=k+ (m-1) is seasonal effect in time series length, and m is Embedded dimensions, and τ is time delay, and this k vector defines the phase space of a reconstruct.

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 Time Series x (t) is divided into t disjoint subsequence, and the length l of each subsequence is l=N/t, has t=6 herein；

(III) to each subsequence, three statistics are calculatedAnd S_cor(t), for

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

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

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

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

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

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

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

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

In formula, r is radius, and its span is 1～4.

(IV) findFirst zero point orFirst minimum point, first zero point or time corresponding to first minimum point are delay time T, have τ=11 herein；

(V) S is found_corThe minimum point of (t), time is Vibration Signal Time Series x (t) first corresponding overall maximum time window τ_w, calculate Embedded dimensions m, for

M=int (τ_w/τ+1)

In formula, int is bracket function.There is m=6 herein.

(4) the appointment region V of phase space reconstruction is determined.

The determination process of described phase space reconstruction appointment region V is:

(I) tieing up phase space at the m of reconstruct selects a centre of sphere to be R_cM tie up suprasphere, the coordinate of the centre of sphere isAnd have

$\stackrel{\&OverBar;}{x}=\frac{1}{N}\underset{n=0}{\overset{N-1}{\mathrm{\&Sigma;}}}x\left(n\right)$

In formula, N is the average of Vibration Signal Time Series.

(II) definition phase space attractor radius R_aFor

$R_a=\sqrt{\frac{1}{N}\underset{n=0}{\overset{N-1}{\mathrm{\&Sigma;}}}{(x\left(n\right)-\stackrel{\&OverBar;}{x})}^2}$

(III) with R in selected phase space_cFor the centre of sphere, R_aFor radius spheric region as specify region V.

(5) Density Distribution of space phase point is calculated.

The calculating process of described space phase point Density Distribution is: divides at equal intervals and calculates space [2R_a,3R_a], it is divided into 5 parts at equal intervals herein.Calculating the Euclidean distance of each phase point distance initial point of phase space reconstruction, statistics phase point drops on counting of each space, obtains the phase point distribution density of each defined basis.

Owing to Euclidean distance is the accepted value mathematical method trying to achieve 2 distances, it is that one of ordinary skilled in the art is all known, therefore no longer carries out column expression and narration at this；

(6) correlation coefficient ρ of spatial density curve before and after load ratio bridging switch action is calculated, if correlation coefficient ρ > 0.8, then judge that load ratio bridging switch running status is normal；If correlation coefficient ρ < 0.8, then judge that load ratio bridging switch running status is abnormal.

The computing formula of described correlation coefficient ρ is

$\mathrm{\&rho;}=\frac{\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}(X_i-\stackrel{\&OverBar;}{X})(Y_i-\stackrel{\&OverBar;}{Y})}{\sqrt{\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{(X_i-\stackrel{\&OverBar;}{X})}^2}\sqrt{\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{(Y_i-\stackrel{\&OverBar;}{Y})}^2}}$

Fig. 2 shows the density profile at designated space of the phase point Density Distribution in the load ratio bridging switch handoff procedure obtained according to said method in the present embodiment, the Calculation of correlation factor result of these two curves is ρ=0.7046, illustrate that load ratio bridging switch running status is abnormal, the mechanical breakdowns such as spring loosens likely occur, need to keep in repair in time, it is to avoid significant trouble occurs.

In operation, collision or friction between mechanism's parts can cause mechanical vibration to load ratio bridging switch, and mechanical vibration are abundant information carriers, and the vibration on load ratio bridging switch switch support, shell is the response of internal multiple phenomenon excitation.If claiming the primary collision of mechanism's parts or friction is a vibration event, then the mechanical oscillation signal that different time of vibration produce can form the time series of a vibration signal in time domain.Therefore, the on-line monitoring that analysis of vibration signal method is incorporated into load ratio bridging switch and fault diagnosis are proposed, the basic thought of this method is to utilize vibration acceleration sensor, the mechanical property of non-invasi ground Monitoring Power Transformer load ratio bridging switch, Real-time Collection, analyze and process the vibration signal on load ratio bridging switch surface, obtain status information and the mode of operation of drive mechanism, accordingly the running status of on-load tap changers of transformers is identified, the Hidden fault in load ratio bridging switch running can be found in time, improve load ratio bridging switch, the reliability of transformator and Operation of Electric Systems and safety.In addition, the vibration signal of load ratio bridging switch is obtained by the vibration acceleration sensor being pasted onto surface, directly it is not electrically connected with whole power system, properly functioning for whole electrical system does not have any impact, can develop into a kind of more accurate, convenient, safe on-line monitoring method.

To sum up, the on-line monitoring method of the on-load tap changers of transformers duty of the present invention is as shown in Figure 3:

(1) vibrating sensor is arranged on the outer surface of on-load tap changers of transformers, the mechanical oscillation signal of Real-time Collection transformer box wall；

(2) mechanical oscillation signal collected is carried out anti aliasing purposes digital filtering and high-speed cache, then pass through high-speed bus and transmit to data analysis module；

(3) data analysis module uses delay coordinate method that vibration signal x (t) is carried out phase space reconfiguration；

(4) the appointment region V of phase space reconstruction is determined；

(5) Density Distribution of space phase point is calculated；

(6) correlation coefficient ρ of spatial density curve before and after load ratio bridging switch action is calculated, if correlation coefficient ρ > 0.8, then judge that load ratio bridging switch running status is normal；If correlation coefficient ρ < 0.8, then judge that load ratio bridging switch running status is abnormal.

The method can be widely used in the on-line monitoring of various on-load tap changers of transformers and fault diagnosis field.

Claims (3)

1. the on-line monitoring method of an on-load tap changers of transformers running status, including the vibration signal gathering on-load tap changers of transformers surface, delay coordinate method is used Vibration Signal Time Series x (t) to carry out phase space reconfiguration and determines the appointment region V of phase space reconstruction, described use postpones coordinate method and Vibration Signal Time Series x (t) is carried out phase space reconfiguration, for

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

In formula, m is Embedded dimensions, and τ is time delay, and this k vector defines the phase space of a reconstruct；

It is characterized in that described on-line monitoring method comprises the following steps:

(1) vibration signal collected is carried out anti aliasing purposes digital filtering and high-speed cache, then pass through high-speed bus and transmit to data analysis module；

(2) postpone after Vibration Signal Time Series x (t) carries out phase space reconfiguration and determine the appointment region V of phase space reconstruction by coordinate method, to calculate the Density Distribution of space phase point using；

(3) correlation coefficient ρ of spatial density curve before and after load ratio bridging switch action is calculated；If correlation coefficient ρ > 0.8, then judge that load ratio bridging switch running status is normal；If correlation coefficient ρ < 0.8, then judge that load ratio bridging switch running status is abnormal；

The on-line monitoring method of its described on-load tap changers of transformers running status, to pass through the monitor in real time to on-load tap changers of transformers surface vibration signals, directly judge the duty of on-load tap changers of transformers, it is easy to operator and finds the exception of on-load tap changers of transformers in time, thus on-load tap changers of transformers being overhauled in time according to abnormal conditions, the fault spoilage of on-load tap changers of transformers can be substantially reduced；

Wherein, the calculating process of its described Embedded dimensions m and delay time T is:

(2-1) standard deviation sigma of Vibration Signal Time Series x (t) is calculated；

(2-2) Vibration Signal Time Series x (t) is divided into t disjoint subsequence, and the length l of each subsequence is l=N/t, has t=6 herein；In formula, N is the average of Vibration Signal Time Series；

(2-3) to each subsequence, three statistics are calculatedAnd S_cor(t), for

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

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

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

$S(m,r,t)=\frac{1}{t}\underset{s=1}{\overset{t}{\&Sigma;}}\&lsqb;C_s(m,r,t)-C_s^m(1,r,t)\&rsqb;$

$S(m,N,r,t)=\frac{1}{t}\underset{s=1}{\overset{t}{\&Sigma;}}\&lsqb;C_s(m,N/t,r,t)-C_s^m(1,N/t,r,t)\&rsqb;,N\&RightArrow;\mathrm{\&infin;}$

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

d_ij=| | X (i)-X (j) | |, d therein_ijFor Euclidean distance；

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

In formula, r is radius, and its span is 1～4；

(2-4) findFirst zero point orFirst minimum point, first zero point or time corresponding to first minimum point are delay time T；

(2-5) S is found_corThe minimum point of (t), time is Vibration Signal Time Series x (t) first corresponding overall maximum time window τ_w, calculate Embedded dimensions m, for

M=int (τ_w/τ+1)

In formula, int is bracket function；

The calculating process of its described space phase point Density Distribution is:

Divide at equal intervals and calculate space [2R_a,3R_a], it is divided into 5 parts at equal intervals, 2R therein herein_aFor the center of circle, 3R_aRadius for circle territory；

Calculating the Euclidean distance of each phase point distance initial point of phase space reconstruction, statistics phase point drops on counting of each space, obtains the phase point distribution density of each defined basis；

The computing formula of its described correlation coefficient ρ is:

$\mathrm{\&rho;}=\frac{\underset{i=1}{\overset{N}{\&Sigma;}}(X_i-\stackrel{\&OverBar;}{X})(Y_i-\stackrel{\&OverBar;}{Y})}{\sqrt{\underset{i=1}{\overset{N}{\&Sigma;}}{(X_i-\stackrel{\&OverBar;}{X})}^2}\sqrt{\underset{i=1}{\overset{N}{\&Sigma;}}{(Y_i-\stackrel{\&OverBar;}{Y})}^2}}.$

2. the on-line monitoring method of the on-load tap changers of transformers running status described in claim 1, it is characterized in that described on-line monitoring method utilizes vibration acceleration sensor, the mechanical property of non-invasi ground Monitoring Power Transformer load ratio bridging switch, Real-time Collection, analyze and process the vibration signal on load ratio bridging switch surface, obtain status information and the mode of operation of drive mechanism, one section of vibration signal in on-load tap changers of transformers course of action is carried out phase space reconfiguration, space phase point Density Distribution in appointment region is calculated in higher dimensional space, then the correlation coefficient of space phase point density profile before and after load ratio bridging switch action is calculated, change according to correlation coefficient is it may determine that go out the running status of on-load tap changers of transformers, accordingly the running status of on-load tap changers of transformers is identified, the Hidden fault in load ratio bridging switch running can be found in time, improve load ratio bridging switch, the reliability of transformator and Operation of Electric Systems and safety.

3. the on-line monitoring method of the on-load tap changers of transformers running status described in claim 1, it is characterized in that the vibration signal on described on-load tap changers of transformers surface is obtained by the vibration acceleration sensor being pasted onto surface, directly not being electrically connected with whole power system, properly functioning for whole electrical system does not have any impact.