Background technology
Existing generator monitoring and diagnosis system is mainly carried out condition monitoring and fault diagnosis to winding insulation, bearing and cooling system, the monitoring and diagnosis shorter mention to genset electric fault.This is that early stage electric fault mainly comprises generator unit stator winding interturn short-circuit, generator rotor interturn short-circuit and generator excited system fault etc. because generator electric fault kind is many, trouble location disperses.For each class electric fault, all need different detection methods at present, different sensors is installed, apply different diagnosis algorithms.Therefore, be difficult to above-mentioned electric fault to unify monitoring and concentrate diagnosis.
Generator rotor interturn short-circuit is a kind of most common failure.National standard has used rotor dynamically to descend air gap detecting coil method to come detection rotor coil whether shorted-turn fault occurs at present, the method need to be installed magnetic flux detector on apart from 10~20mm place, measured rotor surface or generator unit stator slot wedge, can only in generator zero load and three-phase shortcircuit situation, carry out; Under the condition of generator on-load, due to armature reaction, detect DeGrain; And boats and ships alternator is not generally installed this magnetic flux detector.
Generator unit stator winding interturn short-circuit is destructive very strong fault, requires generator protective relaying device to excise rapidly and accurately fault, and protection generator is avoided further damage.But the various protection schemes of generator all can not effecting reaction with branch's small turn number turn-to-turn short circuit to stator winding.The particularly very little short circuit of the number of turn, the electric current in short-circuited conducting sleeve is very large, but generator end and neutral point side curent change are very little, and this has just increased the difficulty of fault detect.And for stator winding, with branch's small turn number turn-to-turn short circuit, also there is no inline diagnosis equipment at present.
Generator excited system fault mainly comprises exciter fault and faults in rotating rectifiers.Similar with main generator, exciter rotor winding also there will be short trouble, the armature of exciter winding in High Rotation Speed state especially, and the possibility that turn-to-turn and phase fault occur is larger.The rectifier of same High Rotation Speed is as run into superpotential and excess current and other abnormal conditions, and power diode may be damaged.During diode breakdown, there will be short circuit and open circuit conditions.Under boats and ships " high temperature, high humidity, high salt " particular surroundings, there is very large hidden danger in the safe operation of generator excited system, but due to marine generator narrow space, cannot adopt the features such as intrusive mood detection means, it is blank that the condition monitoring and fault diagnosis of boats and ships alternator excitation system still belongs to.
Summary of the invention
The invention provides a kind of A.C. brushless synchronous generator failure diagnostic apparatus, solve cannot unifying monitoring and concentrate the problem of diagnosis the early stage electric fault of generator of existing generator failure diagnostic device existence.
A kind of A.C. brushless synchronous generator failure diagnostic apparatus of the present invention, comprise sensor group, signal conditioning circuit, sample circuit, data processor and man-machine interaction unit, user by man-machine interaction unit to data processor input sampling circuit parameter and generator parameter, data processor is controlled sample circuit image data according to sample circuit parameter, described sensor group consists of three voltage sensors and four current sensors, the output signal of each voltage sensor and each current sensor is delivered to respectively signal conditioning circuit and is carried out filtering, voltage stabilizing, after amplitude modulation, by sample circuit, be converted to digital signal, deliver to data processor and carry out fault detect and identifying processing, again by man-machine interaction unit Output rusults, to it is characterized in that:
In described three voltage sensors, first, second, third voltage sensor is measured respectively generator A phase, B phase, C phase armature phase voltage;
In described four current sensors, first, second, third current sensor is measured respectively generator A phase, B phase, C phase armature phase current; The 4th current sensor measurement exciting current of exciter;
Described data processor loads stator winding inter-turn short circuit diagnostic module, rotor interturn short-circuit diagnostic module, exciter fault diagnosis module and Fault Diagnosis of Rotating Rectifier module;
(1) described stator winding inter-turn short circuit diagnostic module, carries out following operation:
(1.1) the fundamental harmonic wave frequency f of calculating generator armature voltage
1: f
1=P * N/60, in formula, the rotor pole logarithm that P is generator, N is generator rated speed;
(1.2) every 5 seconds, the exciting current of exciter digital signal of sample circuit output is carried out to Fast Fourier Transform (FFT), extract exciting current of exciter DC component amplitude I
dC, extracting respectively frequency is 2f
1, 4f
1, 6f
1exciting current of exciter harmonic amplitude
calculate respectively exciting current of exciter second harmonic, four-time harmonic and fifth overtone relative value
with
(1.3) judging whether α (n+1)/α (n) > 300%, be to carry out step (1.4), otherwise man-machine interaction unit does not show; In formula, α (n) represents the α value at first 5 seconds intervals, and α (n+1) represents the α value at latter 5 seconds intervals;
(1.4) judging whether β (n+1)/β (n)≤175% and δ (n+1)/δ (n)≤175%, is that the harmonic components causing for generator asymmetric operation changes, and man-machine interaction unit does not show; Otherwise show stator winding inter-turn short circuit by man-machine interaction unit; In formula, β (n), δ (n) represent respectively β, the δ value at first 5 seconds intervals, and β (n+1), δ (n+1) represent respectively β, the δ value at latter 5 seconds intervals;
(2) described rotor interturn short-circuit diagnostic module, carries out following operation:
(2.1) the fault fundamental harmonic wave frequency f while calculating rotor interturn short-circuit in exciting current of exciter frequency spectrum
2: f
2=N * M/60,
In formula, N is generator rated speed, and M is the parallel branch number of the every phase winding of generator unit stator;
(2.2) every 5 seconds, the exciting current of exciter digital signal of sample circuit output is carried out to Fast Fourier Transform (FFT), extract exciting current of exciter DC component amplitude I
dC, extracting respectively frequency is kf
2exciting current of exciter harmonic amplitude
k=1,2...7,8;
(2.3) judgement
exciting current of exciter harmonic amplitude number whether be greater than 2, be to carry out step (2.4), otherwise man-machine interaction unit do not show, in formula,
represent first 5 seconds intervals
value,
represent latter 5 seconds intervals
value;
(2.4) get
the exciting current of exciter harmonic amplitude of ratio maximum
calculating generator rotor interturn short-circuit eigenwert
j ∈ (1,2...7,8);
(2.5) judge whether ε (n+2)/ε (n+1) > 120%, by man-machine interaction unit, to show rotor interturn short-circuit, otherwise rotor interturn short-circuit feature is not obvious, man-machine interaction unit does not show, in formula, ε (n+1) represents the ε value at latter 5 seconds intervals, and ε (n+2) represents the ε value at latter 5 seconds intervals;
(3) described exciter rotor short circuit in winding diagnostic module, carries out following operation:
(3.1) calculate the fundamental harmonic wave frequency f of armature of exciter voltage
3: f
3=P
1* N/60,
In formula, P
1for the rotor pole logarithm of exciter, N is generator rated speed;
(3.2) every 5 seconds, the exciting current of exciter digital signal of sample circuit output is carried out to Fast Fourier Transform (FFT), extract exciting current of exciter DC component amplitude I
dC, extraction frequency is 2f
3exciting current of exciter harmonic amplitude
calculate exciter rotor short circuit in winding eigenwert
(3.3) judging whether γ (n+1)/γ (n) < 150%, is that exciter rotor winding is not short-circuited, and human-computer interaction interface does not show; Otherwise judging whether 150% < γ (n+1)/γ (n) < 300%, is by man-machine interaction unit, to show exciter rotor winding interturn short-circuit; Otherwise show exciter rotor winding phase fault by man-machine interaction unit; In formula, γ (n) represents the γ value at first 5 seconds intervals, and γ (n+1) represents the γ value at latter 5 seconds intervals;
(4) described rotating rectifier diode breakdown diagnostic module, carries out following operation:
(4.1) calculate the fundamental harmonic wave frequency f of armature of exciter voltage
3: f
3=P
1* N/60,
In formula, P
1for the rotor pole logarithm of exciter, N is generator rated speed;
(4.2) every 5 seconds, the exciting current of exciter digital signal of sample circuit output is carried out to Fast Fourier Transform (FFT), extract exciting current of exciter DC component amplitude I
dC, extraction frequency is f
3exciting current of exciter harmonic amplitude
calculate rotating rectifier diode breakdown eigenwert
(4.3) judging whether λ < 10%, is that rotating rectifier is normal, and human-computer interaction interface does not show; Otherwise judging whether 10% < λ < 55%, is by man-machine interaction unit, to show 1 diode open-circuit of rotating rectifier; Otherwise show 1 diode short circuit of rotating rectifier by man-machine interaction unit.
Described A.C. brushless synchronous generator failure diagnostic apparatus, is characterized in that:
Described man-machine interaction unit is liquid crystal touch screen, and user arranges sample circuit parameter and generator parameter on liquid crystal touch screen, and described sample circuit parameter comprises sample frequency, sampling time and sampling channel; Described generator parameter comprises generator rated speed, stator winding connected mode, stator winding parallel branch number, rotor pole logarithm and exciter excitation number of pole-pairs;
Liquid crystal touch screen shows operation state of generator and fault diagnosis result, and described operation state of generator comprises time domain waveform and the spectrum analysis of threephase armature voltage effective value and frequency, threephase armature current effective value and frequency, each sampling channel; Described fault diagnosis result comprises stator winding inter-turn short circuit, rotor interturn short-circuit, exciter rotor winding interturn short-circuit, exciter rotor winding phase fault, 1 diode open-circuit of rotating rectifier and 1 diode short circuit of rotating rectifier.
Hardware design of the present invention becomes portable set, be specially adapted to the marine generator of small space, utilize the fault diagnosis algorithm of Lab View exploitation, by measuring exciting current of exciter, just can detect the multiple electric faults such as generator unit stator winding interturn short-circuit, rotor interturn short-circuit, exciter rotor winding interturn short-circuit, exciter rotor winding phase fault, rotating rectifier diode 1 tube open circuit and rotating rectifier diode 1 tube short circuit, thereby saved measurement point, multiple intrusive mood sensor needn't be installed in generator; Different model generator for big-and-middle-sized boats and ships has good versatility, and user is as long as input sampling circuit parameter and generator parameter to be detected just can calculate the corresponding various electric faults of judgement automatically, and real-time is good, can meet the requirement of online detection.
Embodiment
Below in conjunction with drawings and Examples, the present invention is further described.
As shown in Figure 1, embodiments of the invention, comprise sensor group, signal conditioning circuit, sample circuit, data processor and man-machine interaction unit, user by man-machine interaction unit to data processor input sampling circuit parameter and generator parameter, data processor is controlled sample circuit image data according to sample circuit parameter, described sensor group consists of three voltage sensors and four current sensors, the output signal of each voltage sensor and each current sensor is delivered to respectively signal conditioning circuit and is carried out filtering, voltage stabilizing, after amplitude modulation, by sample circuit, be converted to digital signal, deliver to data processor and carry out fault detect and identifying processing, again by man-machine interaction unit Output rusults,
In described three voltage sensors, first, second, third voltage sensor is measured respectively generator A phase, B phase, C phase armature phase voltage;
In described four current sensors, first, second, third current sensor is measured respectively generator A phase, B phase, C phase armature phase current; The 4th current sensor measurement generator exciter exciting current;
Described data processor loads stator winding inter-turn short circuit module, rotor interturn short-circuit module, exciter fault diagnosis module and Fault Diagnosis of Rotating Rectifier module.
First, second, third voltage sensor adopts the EM010-9238 type sensor of Switzerland ABB AB; First, second, third, fourth current sensor adopts the 80i-110s type testing current pincers of U.S. Fluke company;
Signal conditioning circuit adopts the A1-P9 signal condition terminal strip of Beijing Altay company, and the current signal that sensor is recorded, voltage signal access signal conditioning circuit are gathered by sample circuit after filtering, voltage stabilizing and amplitude modulation.
Sample circuit adopts the USB2080 data collecting card of Beijing Altay company, and its front-end collection and processing adopt dsp chip, and the highest sample frequency is 400KS/s; Connection terminal has 9 road current Hall interfaces, 3 road voltage Hall interfaces, also has the expansion interface of vibration signal and temperature signal; Digital signal is finally exported by data collecting card USB interface.
Data processor adopts the F2716 type embedded micro PC104 plate of Shenzhen Xi Siwei company, the CPU that arranged in pairs or groups, digital I/O module and communication module; CPU has installed embedded OS Windows XP embedded, and under this operating system, operation utilizes stator winding inter-turn short circuit diagnostic module, rotor interturn short-circuit diagnostic module, exciter fault diagnosis module and the Fault Diagnosis of Rotating Rectifier module of LabView exploitation.
Numeral I/O module shows CPU operation result by man-machine interaction unit, communication module has various communication interfaces, as USB, RS485, Ethernet interface etc.In the present embodiment, condition monitoring and fault diagnosis result arrives host computer by Ethernet interface telecommunication.
Fig. 2 is stator winding inter-turn short circuit diagnostic module operating process block diagram;
Fig. 3 is rotor interturn short-circuit diagnostic module operating process block diagram;
Fig. 4 is exciter rotor short circuit in winding diagnostic module operating process block diagram;
Fig. 5 is rotating rectifier diode breakdown diagnostic module operating process block diagram;
Man-machine interaction unit adopts the NT30-ST121-BR type liquid crystal touch screen of Japanese Omron, for realizing the functions such as demonstration, storage of data processor result of calculation, qualitative with forms such as spectrogram, time domain waveform figure, charts, demonstrate detection and diagnosis result quantitatively.In the present embodiment, generator failure diagnostic routine provides three kinds of diagnostic modes.The other real-time diagnosis of the machine at the scene of being respectively, off-line acquisition of diagnostic and for the telecommunication diagnosis of host computer.Operating personnel also can select reading and diagnosing historical data in main interface.Fig. 6 is Real-time Collection and waveform display interface.In the control panel in this left side, interface, user can arrange the parameter of data acquisition.User can also arrange the parameter of testing generator according to the structure of generator.User can select the electric parameters of certain acquisition channel to carry out time domain waveform demonstration and spectrum analysis.Lower right, interface is respectively the demonstration to the effective value of generator armature line voltage and phase current and frequency.If there is fault, can at diagnostic result place, show fault type, alarm lamp reddens simultaneously.