阅读说明：本技术 一种以振动频率为主线索的水电站稳定性故障诊断方法 (It is a kind of with vibration frequency be main clue power station stable fault diagnostic method ) 是由 徐洪泉 潘罗平 周叶 廖翠林 安学利 王万鹏 李萍萍 李铁友 刘娟 孟龙 于 2019-08-13 设计创作，主要内容包括：本发明涉及一种以振动频率为主线索的水电站稳定性故障诊断方法,该方法首先以振动、压力脉动频率为主线索进行第一次分类,区分出振动频率和故障源一一对应型故障特征；其次是对其它故障源按振动频率是否是水轮机转频的整数倍进行第二次分类,对振动频率不等于水轮机转频整数倍的故障特征按故障频率范围和主要特征进行区分,对振动频率等于水轮机转频整数倍故障特征则采用故障特征剔除法进行筛选；最后对故障特征不明显或多个可能故障特征相混杂,用监测故障特征还难以准确区分故障源时,需进行变转速、变励磁、变负荷等针对性试验,进一步确定故障源。由此,本发明采用层层剥茧的方法,逐渐逼近故障源,诊断效果明确可期。(It is the power station stable fault diagnostic method of main clue that the present invention relates to a kind of with vibration frequency, and this method is first that main clue carries out the first subseries with vibration, the fluctuating frequency of pressure, distinguishes vibration frequency and source of trouble one-to-one correspondence type fault signature；Followed by other sources of trouble by vibration frequency whether be the hydraulic turbine turn frequency integral multiple carry out the second subseries, the fault signature for turning frequency integral multiple not equal to the hydraulic turbine to vibration frequency is distinguished by failure-frequency range and main feature, turns frequency integral multiple fault signature equal to the hydraulic turbine to vibration frequency and fault signature scalping method is then used to screen；Finally unobvious to fault signature or multiple possible breakdown features mutually mix, and when also being difficult to accurately distinguish the source of trouble with monitoring fault signature, need to carry out variable speed, become the test of the specific aims such as excitation, varying duty, further determine that the source of trouble.The present invention gradually approaches the source of trouble, diagnosis effect clearly can the phase using the method for peeling layer by layer as a result,.)

1. it is a kind of with vibration frequency be main clue power station stable fault diagnostic method, which is characterized in that including following step It is rapid:

Step 1: using vibration, the fluctuating frequency of pressure as clue, the first subseries is carried out to Hydropower Plant operation stability: if Vibration frequency belong to source of trouble one-to-one correspondence type fault signature, then directly determine the source of trouble of vibration, otherwise carry out in next step Diagnosis；

Whether step 2: being integral multiple that the hydraulic turbine turns frequency by vibration frequency when vibration frequency and the source of trouble are different a pair of seasonable Carry out the second subseries:

If vibration frequency is not the integral multiple that the hydraulic turbine turns frequency, and belongs to one section of vibration fault frequency range and correspond to a kind of vibration event Barrier, a variety of vibration fault frequency ranges mutually overlapped fault type, combination failure substantive characteristics and vibration frequency range are common Determine the source of trouble；

If vibration frequency is that the hydraulic turbine turns the integral multiple of frequency and single vibration frequency corresponds to multiple vibration source type vibrations, using failure Essential feature scalping method screens possible breakdown source: one source of trouble essential feature of discovery and troubleshooting main feature are not It is corresponding, then the source of trouble is rejected, it is surplus to the rest is the possible source of trouble；

Step 3: it when fault signature is unobvious or multiple possible breakdown features mutually mix, is also difficult to accurately with monitoring fault signature When distinguishing the source of trouble, it need to be supplemented in the test of row specific aim, to distinguish the influence of machinery, electromagnetism, waterpower aspect factor, carried out thinner Diagnosis is caused, finally determines the source of trouble.

2. stable fault diagnostic method in power station according to claim 1, which is characterized in that this method is based on to be lauched The characteristics of various instability problems in power station and rule:

1) many hydroenergy storage stations and installation Francis turbine, the Hydropower Plant of tubular turbine and factory vibration are tight Weight, is due to its vibration frequency f₁=int (Z_g/Z_r)·f_n, wherein Z_gFor guide vane number, Z_rFor runner blade the piece number, f_nFor revolving speed frequency Rate；

2) the arciform convolution of self-excitation is divided to revolution and rotation in the same direction and revolution is with reverse two kinds of rotation: if hydraulic turbine main shaft center rotates The revolution at engineer room center is identical with main shaft sense of rotation, then main shaft throw, the bear vibration frequency measured is critical turn of main shaft Fast frequency；If main-shaft core revolution and main shaft sense of rotation on the contrary, if the main shaft throw, the bear vibration frequency that measure be main shaft The difference of critical speed frequency and rated speed frequency；

3) vortex tape frequency f_vIt should be speed-frequency f_nWith guide vane number Z_gProduct, i.e. f_v=Z_g·f_n。

3. stable fault diagnostic method in power station according to claim 1, which is characterized in that the specific aim, which is tested, is The test for carrying out variable speed, becoming excitation or varying duty.

Technical field

It is the power station stable fault diagnostic method of main clue that the present invention relates to a kind of with vibration frequency, belongs to water engineer Tool technical field.

Background technique

With CFD (Computational Fluid Dynamics, computational fluid dynamics) technology and numerical control processing system The development of technology and being widely used for excellent stainless steel material are made, turbine efficiency increases substantially, the flow passage components such as runner Anti- cavitation corrosion, polishing machine constantly improve, and the major failure and defect encountered in hydroelectric station operation is increasingly to operation stability Aspect is concentrated or inclination, has been increasingly becoming main bugbear or the source of failure that hydraulic turbine operation maintenance faces.

For the safe and stable operation for ensureing power station, many power station settings establish operating states of the units monitoring system, On the one hand repair based on condition of component needs are served, on the one hand to realize that platform is built in Intelligent fault diagnosis, provides technical support.At this In a little status monitoring, repair based on condition of component and fault diagnosis systems, core content is always unit operation stability.With regard to stable fault Intelligent diagnostics for, difficult point is in hydraulic stability.To find out its cause, be because many hydraulic stability problem mechanism not very It is clear, it is difficult to carry out deep from outward appearance to inner essence analysis according to wild effect, Accurate Diagnosis is out of order reason, and mostly uses various Statistical method or fuzzy mathematics method carry out probability analysis, provide the general clue of multifactor difficult point of secondary uncle, it is difficult to give power station Operation and maintenance cause the stable fault intelligent diagnostics in power station to be hesitated to move forward for a long time with objective effective guidance or help, into It opens up very slow.

Summary of the invention

In view of the above-mentioned problems, it is the power station stability event of main clue that the object of the present invention is to provide a kind of with vibration frequency Hinder diagnostic method, to diagnose to the vibration that encounters in hydroelectric station operation, pressure fluctuation equistability failure, determines its failure Reason and attribute.

To achieve the above object, the present invention takes following technical scheme: it is a kind of with vibration frequency be main clue power station Stable fault diagnostic method, comprising the following steps:

Step 1: using vibration, the fluctuating frequency of pressure as clue, Hydropower Plant operation stability divide for the first time Class: if vibration frequency belong to source of trouble one-to-one correspondence type fault signature, directly determine the source of trouble of vibration, otherwise carry out down The diagnosis of one step；

Whether step 2: being that the hydraulic turbine turns the whole of frequency by vibration frequency when vibration frequency and the source of trouble are different a pair of seasonable Several times carry out the second subseries:

If vibration frequency is not the integral multiple that the hydraulic turbine turns frequency, and belongs to one section of vibration fault frequency range and correspond to a kind of vibration Dynamic failure, a variety of vibration fault frequency ranges mutually overlapped fault type, combination failure substantive characteristics and vibration frequency range It is common to determine the source of trouble；

If vibration frequency is that the hydraulic turbine turns the integral multiple of frequency and single vibration frequency corresponds to multiple vibration source type vibrations, use Failure essential feature scalping method screens possible breakdown source: one source of trouble essential feature of discovery and troubleshooting are main special Sign does not correspond to, then rejects the source of trouble, surplus to the rest is the possible source of trouble；

Step 3: it when fault signature is unobvious or multiple possible breakdown features mutually mix, is also difficult to monitoring fault signature When accurately distinguishing the source of trouble, it need to be supplemented in the test of row specific aim, to distinguish the influence of machinery, electromagnetism, waterpower aspect factor, carried out More careful diagnosis finally determines the source of trouble.

The power station stable fault diagnostic method, it is preferred that it is various unstable that this method is based on following power station The characteristics of problem and rule:

1) many hydroenergy storage stations and installation Francis turbine, the Hydropower Plant of tubular turbine and workshop vibration It is dynamic serious, it is due to its vibration frequency f₁=int (Z_g/Z_r)·f_n, wherein Z_gFor guide vane number, Z_rFor runner blade the piece number, f_nTo turn Fast frequency；

2) the arciform convolution of self-excitation is divided to revolution and rotation in the same direction and revolution is with reverse two kinds of rotation: if hydraulic turbine main shaft center Revolution around runner envelope center is identical with main shaft sense of rotation, then main shaft throw, the bear vibration frequency measured is that main shaft faces Boundary's speed-frequency；If main-shaft core revolution and main shaft sense of rotation on the contrary, if the main shaft throw, the bear vibration frequency that measure be The difference of main shaft critical speed frequency and rated speed frequency；

3) vortex tape frequency f_vIt should be speed-frequency f_nWith guide vane number Z_gProduct, i.e. f_v=Z_g·f_n。

The power station stable fault diagnostic method, it is preferred that the specific aim test is progress variable speed, becomes and encourage The test of magnetic or varying duty.

The invention adopts the above technical scheme, which has the following advantages: 1, the present invention is to be based on applicant to water Power machinery hydraulic stability frequecy characteristic, pressure fluctuation propagation law propose on the basis of being furtherd investigate, in conjunction with to water The three aspect factors such as power station waterpower, electromagnetism and machinery cause the summary and induction of various vibration fault frequency characteristics, and as master Clue gradually approaches the source of trouble using the method for peeling layer by layer, and diagnosis effect clearly can the phase.2, the present invention is built upon application People has grasped comprehensively on this essence understanding basis of various stable fault frequecy characteristics, and the connection between theory and practice has scientific base Plinth.

Specific embodiment

Presently preferred embodiments of the present invention will be described in detail below, to be clearer to understand the purpose of the present invention, spy Point and advantage.

Firstly, applicant summarizes as follows in carrying out hydraulic pressure fluctuation genesis mechanism and propagation law research The various instability problems in power station the characteristics of and rule after propose:

1) many hydroenergy storage stations and installation Francis turbine, the Hydropower Plant of tubular turbine and workshop vibration It is dynamic serious, it is due to its vibration frequency f₁=int (Z_g/Z_r)·f_n, wherein Z_gFor guide vane number, Z_rFor runner blade the piece number, f_nTo turn Fast frequency, this explanation produce large range of cavitation cavity, the sky around the guide vane of the hydraulic turbine (or pump turbine) Change cavity and generates additonal pressure pulsation under leaf frequency pressure fluctuation agitation.It, should if it is Francis turbine or pump turbine Cavitation cavity results from the separation of flow vortex of vane inlet, and tubular turbine then results from clearance flow between guide vane end face, it is equal because For vortex center flow velocity is high and generates cavitation.

2) the arciform convolution of self-excitation is divided to revolution and rotation in the same direction and revolution is with reverse two kinds of rotation: if hydraulic turbine main shaft center Revolution around runner envelope center is identical with main shaft sense of rotation, then main shaft throw, the bear vibration frequency measured is that main shaft faces Boundary's speed-frequency；If main-shaft core revolution and main shaft sense of rotation on the contrary, if the main shaft throw, the bear vibration frequency that measure be The difference of main shaft critical speed frequency and rated speed frequency.

3) vortex tape frequency f_vIt should be speed-frequency f_nWith guide vane number Z_gProduct, i.e. f_v=Z_g·f_n.Especially occur The vortex tape of inlet edge of runner blade, when its rotation is by guide vane, the circumferential differential pressure meeting of guide vane outlet edge Its influence is applied on vortex tape: when vortex tape cavitation cavity encounters guide vane outlet low-pressure section, vortex tape pressure reduction can be made, Cavitation cavity is caused further to expand；When vortex tape cavitation cavity encounters guide vane outlet high-pressure section, vortex tape pressure can be made Increase, causes cavitation cavity to shrink and even crumble and fall；Such cyclically-varying then can apply a density to water body in runner channel and become The pressure wave of change, i.e. longitudinal wave.Since the vortex tape is rotated with runner, speed is to turn frequency, and rotation, which is turned around, encounters Z_gA guide vane, Cause Z_gSecondary expansion-contraction causes the fluctuating frequency of pressure to be equal to Z_g·f_n。

4) it summarizes to existing research achievement, could also generalize to the following rule:

1. the pulsation of sub-load draft tube eddy stress causes to vibrate, vibration frequency f₁=(0.1~0.5) f_n；

2. pressure pulsation in high partial load operation causes to vibrate, vibration frequency f₁=(1~4) f_n；

3. mechanical or waterpower imbalance causes radial vibration, throw, vibration frequency f₁=1f_n；

Either statically or dynamically 4. non-uniform air-gap causes to vibrate generator, stator vibration frequency be turn/pole frequency or turn/pole again Frequently；

5. the subharmonic oscillation that fractional-slot winding generates, vibration frequency is 2 times of pole frequencies；

6. class turns frequency pressure fluctuation, vibration frequency f₁=(0.8~1.5) f_n；

7. main shaft or runner labyrinth ring are oval, vibration frequency f₁=2f_n；

8. shaft is tortuous, thrust bearing sliding surface and main shaft out of plumb, upper and lower seal ring decentraction of the hydraulic turbine etc. cause to shake It is dynamic, throw is big, vibration frequency f₁=1f_n；..., etc..

As it can be seen that being directed to each vibration fault, applicant is aware that its frequency range and vibration performance.Therefore, applicant A kind of power station stable fault diagnostic method is proposed as train of thought, this method is that main clue divides failure with vibration frequency Source group, then the source of trouble is found using classification exclusive method, carry out part complementary testing when necessary, is protected for power plant safety stable operation Convoy is driven, specifically includes the following steps:

Step 1: using vibration, the fluctuating frequency of pressure as clue, Hydropower Plant operation stability divide for the first time Class: if vibration frequency belong to source of trouble one-to-one correspondence type fault signature, directly determine the source of trouble of vibration, otherwise carry out down The diagnosis of one step.

For example, if vibration frequency f₁Equal to critical speed frequency f_cOr critical speed frequency f_cWith rated speed frequency Rate f_nDifference (f_c-f_n), it is determined that the arciform whirling vibration of self-excitation occurs；If unit and factory vibration frequency f₁Equal to int (Z_g/ Z_r)·f_n, then a clearance flow cavitation (bulb through-flow turbine) or separation of flow whirlpool cavitation (mixed flow has occurred in explanation around guide vane Reversible Pump-Turbine etc.), the expansion-contraction cycle of cavitation cavity generates additonal pressure pulsation, and the frequency is caused to be shaken strongly It is dynamic.In addition to this, the vibration of the frequencies such as vortex band pressure fluctuation, karman vortex vibration, power frequency vibration also belongs to what the source of trouble relatively determined Pressure fluctuation or vibration.

Whether step 2: being that the hydraulic turbine turns the whole of frequency by vibration frequency when vibration frequency and the source of trouble are different a pair of seasonable Several times carry out the second subseries: if vibration frequency is not the integral multiple that the hydraulic turbine turns frequency, and belonging to one section of vibration fault frequency model Enclose a kind of corresponding vibration fault, a variety of vibration fault frequency ranges mutually overlapped fault type, combination failure substantive characteristics and Vibration frequency range determines the source of trouble jointly.

For example, class turns frequency pressure fluctuation and pressure pulsation in high partial load operation frequency is not the integral multiple for turning frequency, all There is a certain range, and there are also significant portion of overlap joints, are difficult to distinguish only according to frequency.It at this time can be according to the power model respectively occurred It encloses, either with or without occurring, pressure oscillation (class turn frequency pressure fluctuation mostly occur pressure oscillation), load pulsation whether occurs, and (class turns frequency and presses Power pulsation mostly occur load pulsation) etc. distinguish.

If vibration frequency is that the hydraulic turbine turns the integral multiple of frequency and single vibration frequency corresponds to multiple vibration source type vibrations, use Failure essential feature scalping method screens possible breakdown source: one source of trouble essential feature of discovery and troubleshooting are main special Sign does not correspond to, then rejects the source of trouble, surplus to the rest is the possible source of trouble.

In addition, in order to further determine the source of trouble, when vibration frequency is the integral multiple for turning frequency, in combination with other packets The feature of the information containing clear failure carries out fault identification, by taking Hydropower Unit orbit of shaft center as an example, if the main shaft of Hydropower Unit In the presence of slightly misaligning, then orbit of shaft center is oval；If because bearing shell inclination caused seriously to misalign failure, orbit of shaft center In outer " 8 " font, and 2 times to turn frequency ingredient larger；If the rotor of Hydropower Unit exists uneven, orbit of shaft center is close to positive round； If there is rubbing failure, then orbit of shaft center is full of twists and turns, also includes jagged ingredient caused by colliding.

Step 3: it when fault signature is unobvious or multiple possible breakdown features mutually mix, is also difficult to monitoring fault signature When accurately distinguishing the source of trouble, it need to be supplemented in the test of row specific aim, such as carry out variable speed, become the test such as excitation or varying duty, with The influence of machinery, electromagnetism, waterpower etc. factor is distinguished, more careful diagnosis is carried out, finally determines the source of trouble.

The various embodiments described above are merely to illustrate the present invention, wherein the structure of each component, connection type and manufacture craft etc. are all It can be varied, all equivalents and improvement carried out based on the technical solution of the present invention should not exclude Except protection scope of the present invention.