The Portable PD On-Line detector
The utility model relates to a kind of detector, is a kind of Portable PD On-Line detector specifically.
Shelf depreciation belongs to the electrical equipment discharge that the complete short circuit of electrode is got up, and the amplitude of this discharge is all very little usually, and still, they can make insulating property constantly descend really, possibly cause final fault.Shelf depreciation normally causes owing to following reason: the metallic particles of in production and installation process, leaving over, move the discharge that causes under effect of electric field; Epoxy resins insulation residual bubble in casting process; The most advanced and sophisticated discharge that produces; The discharge that the insulator surface electrically conductive particles causes; The discharge that the support member loose contact causes.Shelf depreciation is the transformer insulated aging parameter the sensitiveest with fault of reflection, also is the key factor of quickening transformer insulated poor quality.When the shelf depreciation activity occurs, can produce the electromagnetic wave in superfrequency (UHF) scope, electromagnetic wave can only through insulation course from external detection to.Usually be exactly to adopt detection exterior antenna electromagnetic wave to estimate to gas-insulated switchgear (GIS) Partial Discharge Detection at present, but the sensitivity of this method is low relatively, and receives the influence of outside electromagnetic interference easily.
Summary of the invention
Goal of the invention: the purpose of the utility model is the deficiency to prior art, and a kind of Portable PD On-Line detector is provided, and overcomes the deficiency that existing discharge examination device sensitivity is low, be subject to external interference.
In order to solve the problems of the technologies described above, the utility model has adopted following technical scheme:
A kind of Portable PD On-Line detector; It comprises capacitive coupled sensors and the ultrasonic sensor that links to each other with the local pulse signal respectively; Described capacitive coupled sensors all links to each other with signal amplification circuit with ultrasonic sensor, and signal amplification circuit handles processing unit through waveform processing unit, data acquisition unit, central authorities successively and the man-machine interface unit connects; Described power supply is above-mentioned signal amplification circuit, waveform processing unit, data acquisition unit, central authorities handle processing unit and the man-machine interface unit supplies power.
Wherein, described waveform processing unit comprises electric capacity No. one, and an end of an electric capacity links to each other with the emitter-base bandgap grading of resistance, active transistor respectively; The other end of a said resistance, the base stage of active transistor all link to each other with No. two electric capacity, and the other end of No. two electric capacity links to each other with the other end of an electric capacity; The collection level of active transistor links to each other with No. three electric capacity, No. two resistance respectively, and the other end of No. three electric capacity, No. two resistance all links to each other with the other end of No. two electric capacity.
Wherein, described data acquisition unit is the AT84AS001 chip that atmel corp produces.
Wherein, described CPU is the DSP TMS320C6713BPYP chip of TI company production.
Beneficial effect: the Partial discharge detector of the utility model is one 12 passage instrument, as required can continuous detecting one week or a week above switch cubicle the TEV discharge activities, and show its result; Owing to adopted the complicated mistiming circuit of technology maturation, therefore in that to have a high background effective especially when disturbing, because it can filter out these interference; Adopt non-immersion detecting pattern, but hot line job, and can not have any impact to equipment; Partial discharge detector also can effectively be used to detect intermittent discharge activities, and this discharge activities is left in the basket through regular meeting with the discharge warning system forecast of existing transformer station the time.
Description of drawings
Fig. 1 is the structural representation of utility model.
Fig. 2 is the circuit diagram of waveform processing unit among Fig. 1.
Below in conjunction with accompanying drawing the utility model is done explanation further.
As shown in Figure 1, the Portable PD On-Line detector of the utility model is used to carry out the detection and the measurement of important indicator local discharging level of the insulation assessment of mesohigh power equipment, and its main effect is to realize local discharging level is carried out live monitoring.It comprises the capacitive coupled sensors 1 and ultrasonic sensor 2 that links to each other with the local pulse signal respectively, and described capacitive coupled sensors 1 all links to each other with signal amplification circuit 3 with ultrasonic sensor 2.Signal amplification circuit 3 links to each other with man-machine interface unit 7 through waveform processing unit 4, data acquisition unit 5, CPU 6 successively; Described power supply 8 is above-mentioned signal amplification circuit 3, waveform processing unit 4, data acquisition unit 5, CPU 6 and 7 power supplies of man-machine interface unit, and power supply comprises battery feed circuit and charging circuit two parts.The AT84AS001 chip that described data acquisition unit 5 is produced for atmel corp; The DSP TMS320C6713BPYP chip that CPU 6 is produced for TI company.
As shown in Figure 2, the end that described waveform processing unit 4 comprises 1, number capacitor C 1 of a capacitor C links to each other with the emitter-base bandgap grading of resistance R, active transistor respectively; The other end of a said resistance R, the base stage of active transistor all link to each other with No. two capacitor C 2, and the other end of No. two capacitor C 2 links to each other with the other end of a capacitor C 1; The collection level of active transistor links to each other with No. three capacitor C 3, No. two resistance R L respectively, and the other end of No. three capacitor C 3, No. two resistance R L all links to each other with the other end of No. two capacitor C 2.The filtering circuit of the utility model is an active filter circuit, and the emitter-follower that π type RC filtering circuit that it is made up of capacitor C 1, resistance R, No. two capacitor C 2 and active device transistor are formed is formed by connecting.Can adopt a bigger resistance R; Cooperate to obtain filter effect preferably with No. two capacitor C 2; So that the ripple component of the voltage at No. two capacitor C 2 two ends reduces, the voltage at output voltage and No. two capacitor C 2 two ends is equal basically, so the ripple component of output voltage has also obtained reduction.
CPU 6 comprises CPU, storage unit; The instruction of mainly sending into according to man-machine interface, control data collecting unit 5 carries out data acquisition, and digital signal is analyzed and handled; Accomplish and analyze data, detect pulse signal; And the measurement amplitude, being 2 seconds the clock period partial discharge pulse in the cycle to be counted, and the order of severity of putting according to umber of pulse and amplitude calculating office.
The data of handling are given man-machine interface unit 7 and are shown, the display of man-machine interface unit 7 shows according to the control of CPU 6, shows the result who measures.The design adopts color LCD screen to show, and carries out the shelf depreciation degree with green, yellow, red three kinds of colors and report to the police.
The utility model is gathered shelf depreciation through dual mode: gather electromagnetic wave transient state ground voltage (TEV) through capacitive coupled sensors 1; Gather ultrasound waves through ultrasonic sensor 2, through signal amplification circuit 3 feeble signal that collects is amplified, the signal through the 4 pairs of collections in waveform processing unit carries out Filtering Processing; It is become be suitable electric signal; And carry out data acquisition through data acquisition unit 5, simulating signal is changed to digital signal, and sends into CPU 6.Whole acquisition circuit is measured the shelf depreciation amplitude that produces owing to shelf depreciation, and the purpose that reaches Partial Discharge Detection is analyzed and assessed to the data that measure.
The above only is the preferred implementation of the utility model; Should be pointed out that for those skilled in the art, under the prerequisite that does not break away from the utility model principle; Can also make some improvement and retouching, these improvement and retouching also should be regarded as the protection domain of the utility model.