CN101710161A - Rotor ground on-line monitoring device and method based on adaptive frequency square-wave voltage - Google Patents

Abstract

The invention discloses rotor ground on-line monitoring device and method based on adaptive frequency square-wave voltage. The device comprises a rotor ground real-time on-line monitoring processing unit, an adaptive frequency regulation square-wave power panel, a coupling resistance board and first and second measuring transducers. In the method, the coupling resistance board is adopted to prevent excitation high voltage from striking back the monitoring device; the adaptive frequency square-wave power panel adaptively regulates control voltage frequency corresponding to the power panel according to a fault mode of a motor rotor; the measuring transducers acquire control voltage and measuring voltage which are output by the adaptive frequency square-wave power panel; and the rotor ground real-time on-line monitoring processing unit judges a generator fault according to the control voltage and the measuring voltage. The invention has high monitoring precision and can simply find the fault point, thereby shortening repair time and reducing economic loss brought by power failure.

Description

Rotor ground fault on-Line Monitor Device and method based on adaptive frequency square-wave voltage

Technical field

The present invention relates to a kind of the rotor ground fault on-Line Monitor Device and the method for generator failure detection range based on adaptive frequency square-wave voltage.

Background technology

Generator is the heart of electric system.In the engineering research of electric system, because the generator amature winding is subjected to the influence of mechanical rotation, high temperature, humidity, brake dust or the like environment, rotor insulation against ground reduction and grounding phenomenon happen occasionally.Owing to do not have corresponding online monitoring and fault locator, after ground connection is taken place, do not know the position of earth point, before handling, maintenance to spend the position that a large amount of time removes to search earth point, prolonged the shutdown processing time; Even occur, expect to shut down and handle earth fault, disappeared on the contrary but shut down back ground connection, yet start back ground connection has been taken place again, be that rotor ground fault has just generation under the action of centrifugal force at rotor, under the shutdown situation, always can not find earth point, can't solve problem with grounding;

In engineering, the rotor ground fault on-line monitoring mainly is when generator rotor ground, reports to the police or tripping operation by ground protection, relies on the personal experience to determine the position that fault takes place then.This means also rest in the detection of fault mode, can not accurately judge failure mechanism, find out the final root that causes equipment failure, be easy to generate fault and retransmit, and can not in time show out for the gradual failure of system equipment, can not satisfy the requirement of power plant's repair based on condition of component fully.

Summary of the invention

The present invention seeks to provides a kind of rotor ground fault on-Line Monitor Device and method based on adaptive frequency square-wave voltage at the defective that prior art exists.

The present invention adopts following technical scheme for achieving the above object:

The present invention is based on the rotor ground fault on-Line Monitor Device of adaptive frequency square-wave voltage, it is characterized in that comprising rotor ground fault real time on-line monitoring processing unit, adaptive frequency is adjusted the square wave power plate, repeating resistance plate and first, second measuring transducer, wherein the input end of repeating resistance plate is distinguished the field voltage input end of sending and receiving motor, ground connection behind the output terminal serial connection adaptive frequency adjustment square wave power plate of repeating resistance plate, the control end that adaptive frequency is adjusted the square wave power plate is connected in series the input end that switches through sub-ground connection real time on-line monitoring processing unit behind first measuring transducer, adapts to frequency and adjusts the measuring junction of square wave power plate and be connected in series the input end that switches through sub-ground connection real time on-line monitoring processing unit behind second measuring transducer.

Described rotor ground fault on-Line Monitor Device based on adaptive frequency square-wave voltage, it is characterized in that described adaptive frequency adjustment square wave power plate is made of accessory power supply serial connection measurement resistance in series, the output terminal of one termination repeating resistance plate of accessory power supply, the control voltage output end of accessory power supply connects the input end of first measuring transducer, and the two ends of measuring resistance in series connect the input end of second measuring transducer respectively.

Described rotor ground fault on-Line Monitor Device based on adaptive frequency square-wave voltage, it is characterized in that described rotor ground fault real time on-line monitoring processing unit comprises first, the secondary signal conditioning module, first, the 2nd A/D modular converter, the network equipment, open into modular converter, the MMI interface, central processing unit, DSP, DSP management and Coordination module, the output terminal of input termination first measuring transducer of the first signal condition module wherein, the output terminal of the first signal condition module is connected in series the input end that connects central processing unit behind the A/D modular converter, the output terminal of input termination second measuring transducer of secondary signal conditioning module, the output terminal of secondary signal conditioning module is connected in series the input end that meets DSP behind the 2nd A/D modular converter, open the input end that meets central processing unit and DSP into modular converter respectively, communicate by letter with DSP with central processing unit respectively behind the network equipment serial connection MMI interface, the output terminal of central processing unit and DSP connects the input end of DSP management and Coordination module respectively.

The detection method of described rotor ground fault on-Line Monitor Device based on adaptive frequency square-wave voltage is characterized in that described method is as follows:

Repeating resistance plate: prevent excitation high voltage counterattack monitoring device;

Adaptive frequency square wave power plate: according to the mode adaptive adjustment control electric voltage frequency correspondingly of generator amature fault;

Measuring transducer: the control voltage and the measuring voltage of gathering the output of adaptive frequency square wave power plate;

Rotor ground fault on-line monitoring processing unit: judge generator failure according to described control control voltage and measuring voltage.

The present invention has following beneficial effect with respect to prior art:

1. by the measurement to the positive-negative polarity time constant, self-adaptation is dynamically adjusted the frequency of square wave power plate, to improve the accurate location of device;

2. set up the knowledge base of waveform character information Recognition malfunction;

3. developed the diagnostic method that merges mutually based on wave form analysis and knowledge diagnosis, proposed the diagnostic reasoning model that is suitable for based on Agent;

4. adopt rational state trend analytic approach, the historical data and the online data of system utilized Time Series Method analysis, carry out reasoning according to sign and state and identify the development trend of off status, be i.e. failure prediction;

5. be hardware platform with 32 bit DSP control and testing boards, realize rotor ground fault on-line fault diagnosis and prediction.

6. adopt highly reliable design concept, hardware mode adopts two CPU and two logic outlets;

7. software adopts redundant arithmetic and parameter according to window setting technique;

Thereby the inventive method has avoided the influence of square wave transient state process in the middle of reverse of polarity process to guarantee the precision of rotor monitoring by the mode of adaptive frequency adjustment, has also overcome the influence that additive method (as " table tennis formula ") is subjected to field voltage.After ground connection is taken place, except that grounding alarm, on screen, directly specify immediately and send out machine rotor grounding of pole or certain number line rod ground connection, or the line place ground connection between them, and be presented on the screen with the physical object simulating form, avoid taking a long time and search the trouble spot, shorten the repair time, reduce economic loss brought by power failure.

Description of drawings

Fig. 1: structural drawing of the present invention.

The equivalent circuit diagram of Fig. 2: Fig. 1.

Fig. 3: eliminate the curve map of field voltage for the influence that adds square wave power.A) earth fault position measurement voltage switches between positive or negative DC voltage, and b) change of the saltus step field voltage of field voltage causes that square-wave voltage switches the generation saltus step.

Fig. 4: rotor ground fault real time on-line monitoring processing unit hardware frame figure.

Fig. 5: rotor ground fault real time on-line monitoring processing unit software frame figure.

Fig. 6: each software module topological diagram.

Fig. 7: the hardware block diagram of adaptive electro source plate.

Fig. 8: the frequency of adaptive electro source plate is adjusted schematic diagram.

Description of reference numerals such as following table:

Sequence number	Expression formula	Implication	Attribute
				??1	??R g	Fault resstance	Amount to be separated
??2	??C y	Rotor electric capacity	Amount to be separated
				??3	??α	Earth point position (recently representing to the percentage that earth point accounts for the winding total length of whole rotor) with first section of rotor winding	Amount to be separated
??4	??R v	Repeating resistance	Known quantity
				??5	??U h	Accessory power supply	Known quantity
??6	??R m	Measure resistance in series	Known quantity
				??7	??U m1	Square wave is the measuring voltage of timing	Can measure
??8	??U m2	Measuring voltage when square wave is negative	Can measure
				??9	??T	The square wave sign change cycle of adaptive electro source plate (inverse of frequency)	Can measure
??10	??U fd	Generator excitation voltage	Can measure
				??11	??τ	Time constant	Can measure

Embodiment

Be elaborated below in conjunction with the technical scheme of accompanying drawing to invention:

As shown in Figure 1, the present invention is based on the rotor ground fault on-Line Monitor Device of adaptive frequency square-wave voltage, it is characterized in that comprising rotor ground fault real time on-line monitoring processing unit, adaptive frequency is adjusted the square wave power plate, repeating resistance plate and first, second measuring transducer, wherein the input end of repeating resistance plate is distinguished the field voltage input end of sending and receiving motor, ground connection behind the output terminal serial connection adaptive frequency adjustment square wave power plate of repeating resistance plate, the control end that adaptive frequency is adjusted the square wave power plate is connected in series the input end that switches through sub-ground connection real time on-line monitoring processing unit behind first measuring transducer, adapts to frequency and adjusts the measuring junction of square wave power plate and be connected in series the input end that switches through sub-ground connection real time on-line monitoring processing unit behind second measuring transducer.

Described rotor ground fault on-Line Monitor Device based on adaptive frequency square-wave voltage, it is characterized in that described adaptive frequency adjustment square wave power plate is made of accessory power supply Uh serial connection measurement resistance in series Rm, the output terminal of the termination repeating resistance plate of accessory power supply Uh, the control voltage output end of accessory power supply Uh connects the input end of first measuring transducer, and the two ends of measuring resistance in series Rm connect the input end of second measuring transducer respectively.

As shown in Figure 4, described rotor ground fault on-Line Monitor Device based on adaptive frequency square-wave voltage, it is characterized in that described rotor ground fault real time on-line monitoring processing unit comprises first, the secondary signal conditioning module, first, the 2nd A/D modular converter, the network equipment, open into modular converter, the MMI interface, central processing unit, DSP, DSP management and Coordination module, the output terminal of input termination first measuring transducer of the first signal condition module wherein, the output terminal of the first signal condition module is connected in series the input end that connects central processing unit behind the A/D modular converter, the output terminal of input termination second measuring transducer of secondary signal conditioning module, the output terminal of secondary signal conditioning module are connected in series the input end that meets DSP behind the 2nd A/D modular converter, open the input end that meets central processing unit and DSP into modular converter respectively, communicate by letter with DSP with central processing unit respectively behind the network equipment serial connection MMI interface, the output terminal of central processing unit and DSP connects the input end of DSP management and Coordination module respectively.

To Fig. 1 equivalent circuit diagram as shown in Figure 2:

Then working as square-wave voltage is timing:

$U_{m.1}=\frac{2U_h{R}_m}{R_v+{2R}_g+{2R}_m}(1+\frac{4R_g}{{2R}_m+R_v}{e}^{-\frac{T}{\mathrm{\τ}}})-\frac{(1-2\mathrm{\α})U_{\mathrm{fd}}{R}_m}{R_v+{2R}_g+{2R}_m}---\left(1\right)$

When square-wave voltage when negative:

$U_{m.2}=\frac{-2U_h{R}_m}{R_v+{2R}_g+{2R}_m}(1+\frac{4R_g}{{2R}_m+R_v}{e}^{-\frac{T}{\mathrm{\τ}}})-\frac{(1-2\mathrm{\α})U_{\mathrm{fd}}{R}_m}{R_v+{2R}_g+{2R}_m}---\left(2\right)$

Time constant is:

$\mathrm{\τ}=\frac{(R_m+\frac{R_v}{2})R_g{C}_y}{R_m+\frac{R_v}{2}+R_g}---\left(3\right)$

The central principle of rotor ground fault Device Testing

We can learn three unknown quantitys of three solution of equations according to table one and formula (1), (2), (3).Device is stake resistance, direct earth capacitance and the earth point position that can online in real time records the rotor winding.

The influence that field voltage and earthing position bring is eliminated:

Bias voltage is the pressure drop that electric current that field voltage produces in the loop forms on Rm, and its size is:

$U_m=\frac{(1-2\mathrm{\α})U_{\mathrm{fd}}{R}_m}{R_v+{2R}_g+{2R}_m}$

By: Δ U=|U _M1-U _M2| eliminate.

Fig. 3 has listed and has eliminated field voltage for influence that adds square wave power and solution thereof.

Shown in Fig. 3 (a), the Udc=DC voltage is switched, solution: calculating voltage difference DELTA U=|Um1-Um2|.

Shown in Fig. 3 (a), U1=|Um1-Um2|, U3=|Um3-Um4|, U2=|Um2-Um3|.Solution: locking is measured during voltage jump.

1. decomposition diagnosis policy

From the angle of systematology, system is polymerized according to certain rules by element, and complication system can be divided into several subsystems, at the diagnosis problem of complication system, can adopt the decomposition diagnosis policy.Utilize the method for system level, various faults are carried out classification.Manually to generator amature Fault Diagnosis process, the technician mainly is divided into following step from existing: at first will see the winding diagram of rotor, utilize the voltage failure judgement phenomenon that adds relevant with which loop of field copper; Secondly, the winding of rotor is carried out function divide, according to the knowledge of grasping, the response that the voltage of the square wave that adds produces is analyzed, test repeatedly is until finding earth point.

2.COM with combining of KQML

From the angle of software, the application that develops into of distribute objects technology provides good technical foundation, in the exploitation of intelligent diagnosis system, by adding the Agent that the function corresponding assembly constitutes specific function, just can form difference in functionality Agent.Because based on the widespread use of the COM of Microsoft (a kind of communication mode, a kind of code reuse mode and based on practical object) in the microcomputer field, in Agent, also adopted the COM standard, corresponding module is compiled into corresponding subject component, once sets up the Agent of diagnostic system.The sharpest edges of subject component are that the degree of modularity, opening, the interoperability of program is very strong, utilize simultaneously software renewal, transplant and reuse.In order to realize complicated knowledge exchange, the knowledge that KQML (knowledge query and mainipulation language) is applied between the Agent exchanges, KQML not only can be used as the representation language of knowledge, and have the transport property of network enabled message, thereby make the requirement that is fit to application distribution of obtaining of knowledge.For knowledge communication language such as KQML are introduced, need on COM, realize the KQML message communicating, it is the complicated knowledge exchange that realizes between the Agent, for this reason, each Agent has a KQML message handling device, it forms (message sender, message receiver, message analysis device, virtual knowledge manager and virtual knowledge base) by five parts, and each ingredient of message handling device is the com component of realizing according to COM, standard.

The KQML message sender sends to communication Agent to KQML message, the KQML message that the acceptance of KQML message receiver sends from communication Agent there.The KQML message analysis device is analyzed message according to the knowledge in the virtual knowledge base, carries out corresponding action then.Virtual knowledge manager is the knowledge in the virtual knowledge base of preface, and the external environment condition of the knowledge description agency in the virtual knowledge base itself and it comprises processing power and other corresponding virtual knowledge bases of agency.The application function of Agent is finished by com component, and the application program of wherein non-COM style is packaged into com component with the COM wrapper.In this system architecture, need integrated application function can be used as the functional module of certain Agent, and it is described knowledge deposit in the knowledge base, later Agent just can transfer this functional module according to message.

3. general intelligent body software model

No matter object was being diagnosed Ceng Dangzhong to bear what task, is being in what level, also no matter object takes which type of model, method to finish the work, object all exists some inherences, general character, abstract factor, can be realized by intelligent body notion.Object all has with extraneous comes into contacts with: input, output, the data that are carried on these inputs, the output port have formed information, the difference of the using method of data, information have been embodied the otherness of behavior.High-rise object all has the member of lower classes of oneself, and these members couple together with certain topological structure, and granularity is littler, have similar structure, characteristic and behavior, can describe diagnosis with a kind of general Agent model.Agent comprises input, output, the Agent of subordinate and specific behavior, realizes for ease of software, can represent with the class of object programming:

Class?Agent{

String?Nam；e

List?Input；

List?Output；

List?Components；

Environment()；

Mind()；

Action()

}；

List is a queue data structure, two formations are formed in input, output, the input and output member is a port, the characteristic of port has: object is connected with the object of other same levels by port, finally by port operation is finished, port status has four kinds to the test of object: unknown, not exclusively, normal and unusual.The port notion is specific as follows:

Class?Port{

List?ConnectedAgent

List?Measurement；

PortStatus?Status

}；

Envirement (), Mind (), Action () are abstract methods, and Envirement () finishes the test process to diagnosed object, realize by each port Measurement among Input and the Output is operated; Mind () finishes the adjustment of Agent inside; Action () method is finished the object specific behavior, and task is to return the state of certain port.

Reusable member in 3 diagnostic systems

Mainly comprise: fault information acquisition class A of geometric unitA, parameter class A of geometric unitA, inference machine class A of geometric unitA, interpreter class A of geometric unitA

1. parameter class A of geometric unitA

The parameter class A of geometric unitA is used to deposit the basic parameter of reflection rotor operation state, and as voltage, resistance etc., its attribute is parametric type, parameter name, parameter information.The basic operation of parameter class comprises the assignment to parameter, the breath of being named, winning the confidence.

2. knowledge class A of geometric unitA

The knowledge class A of geometric unitA is an implication, and its basic operation has: judge that some given facts or conclusion whether in the prerequisite or conclusion of knowledge, calculate total findings data, calculate total prerequisite number.Attribute comprises title, prerequisite, conclusion and the confidence level of knowledge during the knowledge class A of geometric unitA.

3. inference machine class A of geometric unitA

The inference machine class can respond the true message that sends, and searches required parametric data information to the parameter class, sends message to the knowledge class again, requires its loopback whether to satisfy the information of knowledge, also needs to realize various Search Control policing algorithms, and the control inference direction.

4. explanation class A of geometric unitA

In the middle of the reasoning process or after the reasoning end, may need to know the foundation of reasoning path, reasoning, when the user puts question to, the user may need to know the reason of inquiry, so need to explain class A of geometric unitA.

5. knowledge base member

The knowledge base member realize to knowledge tissue, administer and maintain, abbreviate the management of knowledge as.

The overall topology of system describes with regard to each unit among the figure one respectively as shown in Figure 1 below

Rotor ground fault real time on-line monitoring processing unit software frame such as Fig. 5, shown in Figure 6:

Diagnosis unit is by carrying out processing transformation to monitor signal, extract responsive failure symptom, in conjunction with the expertise and the data of diagnostic knowledge base, diagnose out of order classification, trouble spot and fault progression trend, and diagnostic result is transmitted back to DSP management and Coordination module.

Data processing module mainly carries out the inspection of validity to the status signal of gathering, and rejects distortion data, prevents erroneous judgement, with pretreated data qualification packing, puts into corresponding data buffer and deposits real-time data base in.Data analysis module is taked different digital signal processing methods at different signals, as frequency spectrum analysis methods such as wavelet analysis, Kalman filtering analyses, obtains the characteristic quantity of each monitor signal, forms failure symptom.

The frequency self-adaption module is according to the time constant of additional power source polar switching, and self-adaptation is adjusted electric voltage frequency, so that additional power source is in the optimum frequency output state always.

The status information that life-span early warning module gets according to monitoring is analyzed with the time sequence analysis method the historical data and the online data of system, short-term forecasting hypomere time operation conditions, the possibility of judgement rotor winding earth.

The diagnostic reasoning module is according to the result of data analysis, to known fault, based on malfunction identification knowledge base, utilizes current fault signature, the immediate reasoning type that is out of order.

Diagnostic knowledge base comprises quantitative information, system architecture and the job information of fault, diagnostician's diagnostic method etc. to the helpful knowledge of fault diagnosis, comprises characteristic quantity threshold value, occurrence probability etc.

Integrated data base comprises the quantity of state of the various rotor windings that record, the fault signature value after the health status of current rotor winding and the process data processing.

The hardware block diagram of adaptive electro source plate is as shown in Figure 7:

U _h, promptly 25, of terminal row No. 27 terminal output voltages are ± 50V;

U _Control, promptly 19, of terminal row No. 21 terminal output voltages should be less than 5V;

U _Meas, promptly 15, of terminal row No. 17 terminal output voltages should be less than 5V;

Terminal 25,27 maximum output current values are: ± 20mA;

Terminal 19,21 maximum output current values are: ± 2mA;

Terminal 15,17 maximum output current values are: ± 2mA;

Terminal 7,9 input voltages are: 230V;

Terminal 7,11 input voltages are: 125V;

The frequency of adaptive electro source plate is adjusted schematic diagram as shown in Figure 8.

The repeating resistance plate:

R _v=40 kilo-ohms;

The series connection measuring resistance:

R _m=400 ohm.

Claims (4)

1. rotor ground fault on-Line Monitor Device based on adaptive frequency square-wave voltage, it is characterized in that comprising rotor ground fault real time on-line monitoring processing unit, adaptive frequency is adjusted the square wave power plate, repeating resistance plate and first, second measuring transducer, wherein the input end of repeating resistance plate is distinguished the field voltage input end of sending and receiving motor, ground connection behind the output terminal serial connection adaptive frequency adjustment square wave power plate of repeating resistance plate, the control end that adaptive frequency is adjusted the square wave power plate is connected in series the input end that switches through sub-ground connection real time on-line monitoring processing unit behind first measuring transducer, adapts to frequency and adjusts the measuring junction of square wave power plate and be connected in series the input end that switches through sub-ground connection real time on-line monitoring processing unit behind second measuring transducer.

2. the rotor ground fault on-Line Monitor Device based on adaptive frequency square-wave voltage according to claim 1, it is characterized in that described adaptive frequency adjustment square wave power plate is made of accessory power supply (Uh) serial connection measurement resistance in series (Rm), the output terminal of one termination repeating resistance plate of accessory power supply (Uh), the control voltage output end of accessory power supply (Uh) connects the input end of first measuring transducer, and the two ends of measuring resistance in series (Rm) connect the input end of second measuring transducer respectively.

3. the rotor ground fault on-Line Monitor Device based on adaptive frequency square-wave voltage according to claim 1, it is characterized in that described rotor ground fault real time on-line monitoring processing unit comprises first, the secondary signal conditioning module, first, the 2nd A/D modular converter, the network equipment, open into modular converter, the MMI interface, central processing unit, DSP, DSP management and Coordination module, the output terminal of input termination first measuring transducer of the first signal condition module wherein, the output terminal of the first signal condition module is connected in series the input end that connects central processing unit behind the A/D modular converter, the output terminal of input termination second measuring transducer of secondary signal conditioning module, the output terminal of secondary signal conditioning module is connected in series the input end that meets DSP behind the 2nd A/D modular converter, open the input end that meets central processing unit and DSP into modular converter respectively, communicate by letter with DSP with central processing unit respectively behind the network equipment serial connection MMI interface, the output terminal of central processing unit and DSP connects the input end of DSP management and Coordination module respectively.

4. the detection method of the rotor ground fault on-Line Monitor Device based on adaptive frequency square-wave voltage as claimed in claim 1 is characterized in that described method is as follows:

Repeating resistance plate: prevent excitation high voltage counterattack monitoring device;

Adaptive frequency square wave power plate: according to the mode adaptive adjustment control electric voltage frequency correspondingly of generator amature fault;

Measuring transducer: the control voltage and the measuring voltage of gathering the output of adaptive frequency square wave power plate;

Rotor ground fault on-line monitoring processing unit: judge generator failure according to described control control voltage and measuring voltage.

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