CN102063547B - Modeling process of friction energy model of dynamic and static crushing and grinding faults of generator as well as fault detection method - Google Patents

Abstract

The invention discloses a modeling process of a friction energy model of dynamic and static crushing and grinding faults of a generator as well as a fault detection method. Two orthogonal displacement sensors at an angle of 45 degrees are respectively mounted at the left and the right of a measuring surface i of a certain bearing of the generator; an X sensor in the X direction and a Y sensor in the Y direction deduce an energy model of the dynamic and static crushing and grinding faults of the generator through mathematical formulas, and the presentation of dynamic and static crushing and grinding faults of the generator with friction energy accords with the fault characteristics of the crushing and grinding of an oil block and a sealing tile very much. Practically proved, the analysis of the dynamic and static crushing and grinding faults of the generator with a friction energy principle is more sensitive, direct and accurate than a traditional friction force analysis method and is more convenient to find friction faults at early stage. The invention also discloses a method for detecting the dynamic and static crushing and grinding faults of the generator by adopting the established friction energy model.

Description

Modeling process and the fault detection method of generator impact and rub fault frictional energy model

Technical field

The present invention relates to the field diagnostic new method in rotating machinery vibrating diagnosis and control field, specifically refer to modeling process and the fault detection method of generator impact and rub fault frictional energy model.

Background technology

A large amount of research datas about the generator impact and rub in the prior art nearly all are to be conceived on the characteristic of " friction force ", and therefore the conclusion that obtains is: the dynamics right and wrong of friction are linear, and its spectrum analysis must have very abundant harmonic components.This but " traditional friction characteristic " bumps in the real work of grinding fault at our analysis generator and really is difficult to see.

When the dynamics of friction appearred in actual rotor, friction force is very big, that is to say, and when seeing these friction characteristics, often be friction late period sometimes, cause serious mistaken diagnosis.Therefore we must find at the friction initial stage, and the physical quantity of responsive reflection is just arranged.Discover that at the friction initial stage effect of friction force is not very big, but really often great changes have taken place for unit vibration, after this mainly was impact and rub, the rotor local heating caused thermal flexure, has broken the original equilibrium state of unit.This is in operation and changes the energy of equilibrium state, is defined as " frictional energy ".Frictional energy has following characteristic:

(1) Zhen Dong principal character is unbalanced feature

(2) frictional energy mainly reflects the variation of equilibrium state in service

(3) variation of equilibrium state is continuous, is used for distinguishing element falling

(4) vibration amplitude not necessarily increases, and vibrates to reduce also to show as to have frictional energy

(5) vibration amplitude is constant, and the variation of phase place also will reflect in frictional energy

(6) frictional energy reference bearing metal temperature and lubricating oil temperature are as weighting correction, better effects if

(7) " frictional energy ", this index and vibrational energy have the difference of essence, if unit vibrates when steady working condition is moved greatly, its vibrational energy is just big, but its " frictional energy " may be very little, even are zero

(8) frictional energy is that vibration changes, and phase place changes, an overall target of temperature variation and mutual relationship thereof.

Summary of the invention

One of purpose of the present invention provides a kind of modeling process of generator impact and rub fault frictional energy model, and this frictional energy model can be found the early stage impact and rub tribological failure of generator sensitiveer, more accurately.

This purpose of the present invention realizes by following technical solution: the modeling process of generator impact and rub fault frictional energy model, and it comprises following process:

Measure face i two orthogonal displacement transducers be installed in the position of each miter angle of and arranged on left and right sides at generator bearing place: the X sensor of X-direction and the Y sensor of Y-direction, and the original power frequency component of power frequency vibration is expressed as respectively:

$\left\{\begin{array}{c}{x}_i=A_i\cos (\mathrm{\ωt}-{\mathrm{\α}}_i)=s_{\mathrm{xi}}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{xi}}\cos \left(\mathrm{\ωt}\right)\\ y_i=B_i\cos (\mathrm{\ωt}-{\mathrm{\β}}_i)=s_{\mathrm{yi}}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{yi}}\cos \left(\mathrm{\ωt}\right)\end{array}\right.---\left(1\right)$

In the formula:

ω is angular velocity of rotation

x _iFor power frequency vibration at the X-direction vibration signal

A _iFor power frequency vibration at the X-direction vibration amplitude

α _iFor power frequency vibration in the X-direction phase place

s _Xi=A _iSin α _iBe signal x _iThe sine term coefficient

c _Xi=A _iCos α _iBe signal x _iThe cosine term coefficient

y _iFor power frequency vibration at the Y-direction vibration signal

B _iFor power frequency vibration at the Y-direction vibration amplitude

β _iFor power frequency vibration in the Y-direction phase place

s _Yi=B _iSin β _iBe signal y _iThe sine term coefficient

c _Yi=B _iCos β _iBe signal y _iThe cosine term coefficient

When n measurement face, the original power frequency vibration vector representation of the arbitrary measurement face i of generator is:

r _i＝[s _xi，c _xi，s _yi，c _yi]，i＝1，2，…，n (2)

Wherein, measurement face is generator vapour end bearing, encourage one or more in end bearing, collector ring bearing or the exciter bearing, and all the parameter matrix expression formula of the power frequency vibration of supporting place measurement faces is:

$R=\left[\begin{array}{c}{r}_1\\ r_2\\ \·\\ \·\\ \·\\ r_n\end{array}\right]---\left(3\right)$

After bumping the mill fault, rotor produces thermal deformation, and the power frequency component change list of measuring surface vibration is shown:

$\left\{\begin{array}{c}{x}_i^{\′}=A_i^{\′}\cos (\mathrm{\ωt}-{\mathrm{\α}}_i^{\′})=s_{\mathrm{xi}}^{\′}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{xi}}^{\′}\cos \left(\mathrm{\ωt}\right)\\ y_i^{\′}=B_i^{\′}\cos (\mathrm{\ωt}-{\mathrm{\β}}_i^{\′})=s_{\mathrm{yi}}^{\′}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{yi}}^{\′}\cos \left(\mathrm{\ωt}\right)\end{array}\right.---\left(4\right)$

Be r ' with vector representation _i=[s ' _Xi, c ' _Xi, s ' _Yi, c ' _Yi], all the power frequency vibration of supporting place measurement face is expressed as R ', on the face of measurement i, and the vibration power frequency variation Δ r that generator impact and rub fault causes _iFor:

Δr _i＝r′ _i-r _i＝[Δs _xi，Δc _xi，Δs _yi，Δc _yi] (5)

At whole supporting place measurement face places, the vibration power frequency variation Δ R that generator impact and rub fault causes is expressed as:

ΔR＝[Δr ₁′Δr ₂′…Δr _n′] ^T (6)

Each power frequency component variation of measuring face all can be expressed as an ellipse, the frictional energy of the power frequency vibration that can experience for a certain vibration survey face is represented with ellipse area, wherein, the expression formula at measurement face i place long axis of ellipse, minor axis and major axis inclination angle is:

In the formula:

a _iFor measuring face i place long axis of ellipse

b _iFor measuring face i place long axis of ellipse

For measuring long axis of ellipse inclination angle, face i place

At the face of measurement i place, the frictional energy Q that the power frequency vibration of generator impact and rub fault characterizes _vExpression formula is:

Q _V＝πa _ib _i (8)

The present invention can do following improvement: when the influence of considering bearing metal temperature, lubricating oil temperature, and total frictional energy Q _RBe expressed as:

Q _R＝Q _V+Q _M+Q _O (9)

In the formula, Q _MExpression causes the frictional energy of bearing metal temperature variation, Q _OExpression causes the frictional energy that lubricating oil temperature changes, and they all can calculate by quality, specific volume and temperature rise.

Compared with prior art, the present invention replaces traditional " friction force ", characterizes generator impact and rub fault with new " frictional energy ", very meets the fault characteristic that generator oil catch, sealing bearing bush bump mill; Concept according to " frictional energy ", by the information fusion to power frequency vibration, the physical model expression formula of frictional energy has been proposed first, facts have proved usefulness " frictional energy " principle analysis generator impact and rub fault, than former " friction force " analytical approach sensitiveer, more direct more accurate, be convenient to the early detection tribological failure more.

Two of purpose of the present invention provides a kind of generator impact and rub fault detection method, adopts above-mentioned frictional energy model to detect generator impact and rub tribological failure.

This purpose of the present invention realizes by following technical solution: a kind of generator impact and rub fault detection method, and it comprises following process:

(1) measures face i at generator bearing place two orthogonal displacement transducers are installed in the position of each miter angle of and arranged on left and right sides: the X sensor of X-direction and the Y sensor of Y-direction, wherein, measurement face is generator vapour end bearing, encourages one or more in end bearing, collector ring bearing or the exciter bearing;

(2) measurement data by obtaining in the acquisition step (1) adopts the frictional energy model of above-mentioned foundation to detect generator impact and rub tribological failure.

Description of drawings

Fig. 1 is that the position of X sensor and Y sensor concerns synoptic diagram among the present invention;

Fig. 2 is the synoptic diagram that the power frequency component change list of each measurement face among the present invention is shown an ellipse.

Embodiment

The modeling process of generator impact and rub fault frictional energy model, it comprises following process:

Measure face i two orthogonal displacement transducers be installed in the position of each miter angle of and arranged on left and right sides at generator bearing place: the X sensor of X-direction and the Y sensor of Y-direction as shown in Figure 1, the original power frequency component of power frequency vibration is expressed as respectively:

$\left\{\begin{array}{c}{x}_i=A_i\cos (\mathrm{\ωt}-{\mathrm{\α}}_i)=s_{\mathrm{xi}}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{xi}}\cos \left(\mathrm{\ωt}\right)\\ y_i=B_i\cos (\mathrm{\ωt}-{\mathrm{\β}}_i)=s_{\mathrm{yi}}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{yi}}\cos \left(\mathrm{\ωt}\right)\end{array}\right.---\left(1\right)$

In the formula:

ω is angular velocity of rotation

x _iFor power frequency vibration at the X-direction vibration signal

A _iFor power frequency vibration at the X-direction vibration amplitude

α _iFor power frequency vibration in the X-direction phase place

s _Xi=A _iSin α _iBe signal x _iThe sine term coefficient

c _Xi=A _iCos α _iBe signal x _iThe cosine term coefficient

y _iFor power frequency vibration at the Y-direction vibration signal

B _iFor power frequency vibration at the Y-direction vibration amplitude

β _iFor power frequency vibration in the Y-direction phase place

s _Yi=B _iSin β _iBe signal y _iThe sine term coefficient

c _Yi=B _iCos β _iBe signal y _iThe cosine term coefficient

When n measurement face, the original power frequency vibration vector representation of the arbitrary measurement face i of generator is:

r _i＝[s _xi，c _xi，s _yi，c _yi]，i＝1，2，…，n (2)

Wherein, measurement face is generator vapour end bearing, encourage one or more in end bearing, collector ring bearing or the exciter bearing, and all the parameter matrix expression formula of the power frequency vibration of supporting place measurement faces is:

$R=\left[\begin{array}{c}{r}_1\\ r_2\\ \·\\ \·\\ \·\\ r_n\end{array}\right]---\left(3\right)$

After bumping the mill fault, rotor produces thermal deformation, and the power frequency component change list of measuring surface vibration is shown:

$\left\{\begin{array}{c}{x}_i^{\′}=A_i^{\′}\cos (\mathrm{\ωt}-{\mathrm{\α}}_i^{\′})=s_{\mathrm{xi}}^{\′}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{xi}}^{\′}\cos \left(\mathrm{\ωt}\right)\\ y_i^{\′}=B_i^{\′}\cos (\mathrm{\ωt}-{\mathrm{\β}}_i^{\′})=s_{\mathrm{yi}}^{\′}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{yi}}^{\′}\cos \left(\mathrm{\ωt}\right)\end{array}\right.---\left(4\right)$

Be r ' with vector representation _i=[s ' _Xi, c ' _Xi, s ' _Yi, c ' _Yi], all the power frequency vibration of supporting place measurement face is expressed as R ', on the face of measurement i, and the vibration power frequency variation Δ r that generator impact and rub fault causes _iFor:

Δr _i＝r _i′-r _i＝[Δs _xi，Δc _xi，Δs _yi，Δc _yi] (5)

At whole supporting place measurement face places, the vibration power frequency variation Δ R that generator impact and rub fault causes is expressed as:

ΔR＝[Δr ₁′Δr ₂′…Δr _n′] ^T (6)

Each power frequency component variation of measuring face all can be expressed as an ellipse as shown in Figure 2, the frictional energy of the power frequency vibration that can experience for a certain vibration survey face is represented with ellipse area, wherein, the expression formula at measurement face i place long axis of ellipse, minor axis and major axis inclination angle is:

In the formula:

a _iFor measuring face i place long axis of ellipse

b _iFor measuring face i place long axis of ellipse

For measuring long axis of ellipse inclination angle, face i place

At the face of measurement i place, the frictional energy Q that the power frequency vibration of generator impact and rub fault characterizes _vExpression formula is:

Q _V＝πa _ib _i (8)

When the influence of considering bearing metal temperature, lubricating oil temperature, total frictional energy Q _RBe expressed as:

Q _R＝Q _V+Q _M+Q _O (9)

In the formula, Q _MExpression causes the frictional energy of bearing metal temperature variation, Q _OExpression causes the frictional energy that lubricating oil temperature changes, and they all can calculate by quality, specific volume and temperature rise.

It is pointed out that the generator that takes place at scene repeatedly bumps the mill fault, oil catch bumps mill and sealing bearing bush bumps mill, does not all have significantly reflection on block bearing temperature and lubricating oil return temperature.

Therefore, after proposing the frictional energy concept, the foundation of its model still based on expression formula (8), is used Q _VRepresent frictional energy, and be used for actual friction detection.

The present invention also provides the detection method that adopts above-mentioned frictional energy model to detect generator impact and rub tribological failure, and it comprises following process:

(1) measures face i at generator bearing place two orthogonal displacement transducers are installed in the position of each miter angle of and arranged on left and right sides: the X sensor of X-direction and the Y sensor of Y-direction, as shown in Figure 1, wherein, measurement face is generator vapour end bearing, encourages one or more in end bearing, collector ring bearing or the exciter bearing;

(2) measurement data by obtaining in the acquisition step (1) adopts the frictional energy model of above-mentioned foundation to detect generator impact and rub tribological failure.

In real cases is analyzed, we have made up the frictional energy spectrogram, for being is also taken all factors into consideration rotating speed or the frequency of bumping mill, being different under the low speed and following frictional energy grade at a high speed, to grind fault diagnosis be highly effective for opening bumping of machine process for this.

No. 3 units of certain power plant are fastened the extra large electric 600MW of group supercritical unit, and 14:40 starts red switch for the first time afternoon on the 1st September in 2006, adopt high, intermediate pressure cylinder combined launch mode, and starting pre-eccentric is 56 microns.After under 600r/min, checking audition; rotating speed rises to 2350r/min warming-up half an hour; rise to 2850r/min then and carry out the valve switching; 6 watts, 7 watts (generator before watt) vibration valve between transfer period power frequency vibration climb comparatively fast; the field staff finds that 6 pad bearing case motor sides oil shelves place has Mars to emerge, for guaranteeing that safe speed of rotation does not reach 3000r/min and namely beats gate stop-start.By the frictional energy spectrum analysis, the frictional energy that generator 7 bricklayer frequency components obtain after merging sharply increases at 2850r/min, and the mill fault has taken place to bump rotor.7 watts of axles of reduction of speed process discovery shake and cross threshold vibration greater than boosting velocity procedure in reduction of speed process Bode figure, and there has been certain interim thermal flexure in rotor owing to bump mill.Shut down the back and check, find that the outer oil shelves of bearing housing electricity side have with axle journal obviously to bump the polishing scratch mark, will outer oil shelves repair to scrape and increase the gap, start 7 watts of vibrations again and recover normal.

Claims (2)

1. method of utilizing generator impact and rub fault frictional energy model to detect generator impact and rub tribological failure, it comprises following process:

Position at each miter angle of axis and arranged on left and right sides of the measurement face i at generator bearing place is equipped with two orthogonal displacement transducers: the X sensor of X-direction and the Y sensor of Y-direction, and the original power frequency component of power frequency vibration is expressed as respectively:

$\left\{\begin{array}{c}{x}_i=A_i\cos (\mathrm{\ωt}-{\mathrm{\α}}_i)=s_{\mathrm{xi}}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{xi}}\cos \left(\mathrm{\ωt}\right)\\ y_i=B_i\cos (\mathrm{\ωt}-{\mathrm{\β}}_i)=s_{\mathrm{yi}}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{yi}}\cos \left(\mathrm{\ωt}\right)\end{array}\right.---\left(1\right)$

In the formula:

ω is angular velocity of rotation

T is the time

x _iFor power frequency vibration at the X-direction vibration signal

A _iFor power frequency vibration at the X-direction vibration amplitude

α _iFor power frequency vibration in the X-direction phase place

s _Xi=A _iSin α _iBe signal x _iThe sine term coefficient

c _Xi=A _iCos α _iBe signal x _iThe cosine term coefficient

y _iFor power frequency vibration at the Y-direction vibration signal

B _iFor power frequency vibration at the Y-direction vibration amplitude

β _iFor power frequency vibration in the Y-direction phase place

s _Yi=B _iSin β _iBe signal y _iThe sine term coefficient

c _Yi=B _iCos β _iBe signal y _iThe cosine term coefficient

When n measurement face, the original power frequency vibration vector representation of the arbitrary measurement face i of generator is:

r _i＝[s _xi,c _xi,s _yi,c _yi]，i＝1,2,…,n （2）

Wherein, measurement face is generator vapour end bearing, encourage one or more in end bearing, collector ring bearing or the exciter bearing, and all the parameter matrix expression formula of the power frequency vibration of supporting place measurement faces is:

$R=\left[\begin{array}{c}{r}_1\\ r_2\\ .\\ .\\ .\\ r_n\end{array}\right]---\left(3\right)$

After bumping the mill fault, rotor produces thermal deformation, and the power frequency component change list of measuring surface vibration is shown:

$\left\{\begin{array}{c}{x}_i^{\′}=A_i^{\′}\cos (\mathrm{\ωt}-{\mathrm{\α}}_i^{\′})=s_{\mathrm{xi}}^{\′}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{xi}}^{\′}\cos \left(\mathrm{\ωt}\right)\\ y_i^{\′}=B_i^{\′}\cos (\mathrm{\ωt}-{\mathrm{\β}}_i^{\′})=s_{\mathrm{yi}}^{\′}\sin \left(\mathrm{\ωt}\right)+c_{\mathrm{yi}}^{\′}\cos \left(\mathrm{\ωt}\right)\end{array}\right.---\left(4\right)$

With vector representation be

All the power frequency vibration of supporting place measurement face is expressed as R ',

On the face of measurement i, the vibration Gong that generator impact and rub fault causes is Bianization Liang ⊿ r frequently _iFor:

${\mathrm{\Δr}}_i=r_i^{\′}-r_i=[{\mathrm{\Δs}}_{\mathrm{xi}},{\mathrm{\Δc}}_{\mathrm{xi}},{\mathrm{\Δs}}_{\mathrm{yi}},{\mathrm{\Δc}}_{\mathrm{yi}}]---\left(5\right)$

At whole supporting place measurement face places, the vibration Gong that generator impact and rub fault causes Bianization Liang ⊿ R frequently is expressed as:

$\mathrm{\ΔR}={\left[\begin{array}{cccc}{\mathrm{\Δr}}_1^{\′}& {\mathrm{\Δr}}_2^{\′}& ...& {\mathrm{\Δr}}_n^{\′}\end{array}\right]}^T---\left(6\right)$

Each power frequency component variation of measuring face all can be expressed as an ellipse, the frictional energy of the power frequency vibration that can experience for a certain vibration survey face is represented with ellipse area, wherein, the expression formula at measurement face i place long axis of ellipse, minor axis and major axis inclination angle is:

In the formula:

a _iFor measuring face i place long axis of ellipse

b _iFor measuring the oval minor axis in face i place

For measuring long axis of ellipse inclination angle, face i place

At the face of measurement i place, the frictional energy Q that the power frequency vibration of generator impact and rub fault characterizes _vExpression formula is:

Q _V＝πa _ib _i （8）

By gathering the measurement data that obtains in the above-mentioned steps, adopt the frictional energy model of above-mentioned foundation to detect generator impact and rub tribological failure.

2. the method for utilizing generator impact and rub fault frictional energy model to detect generator impact and rub tribological failure according to claim 1, it also comprises following process: when the influence of considering bearing metal temperature, lubricating oil temperature, total frictional energy Q _RBe expressed as:

Q _R＝Q _V+Q _M+Q _O （9）

In the formula, Q _MExpression causes the frictional energy of bearing metal temperature variation, Q _OExpression causes the frictional energy that lubricating oil temperature changes, and they all can calculate by quality, specific volume and temperature rise.

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