A kind of temperatures of high-voltage electrified bodies on-Line Monitor Device
Technical field
The utility model relates to a kind of temperature measuring equipment, is specially a kind of temperatures of high-voltage electrified bodies on-Line Monitor Device.
Background technology
Power equipment because joule heating and dielectric loss can cause the rising of local temperature, is the major reason that causes power equipment to break down owing to long term thermal accumulates the local temperature that produces too high in the process of operation.As in the power equipment because insulating material resistivity reduces or there is shelf depreciation in inside, the capital causes the increase of loss and the rising of temperature, this will cause the accelerated deterioration of insulating material and cause device damage, and for example there are a large amount of conductor crimping connections and the position of socket connection in the power equipment, because oxidation, reason such as loosening can cause these position loose contacts, contact resistance increases, when load current by the time can produce the local overheating phenomenon, and the rising of temperature makes oxidation aggravate, so contact resistance further increases, cause vicious cycle, finally cause the equipment cisco unity malfunction, even burn.According to national rule, the A class F insulating material F guarantees that the maximum safety temperature of reliability service is 105 ℃, and the long-term maximum operating temperature of metal bolts jointing be 80 ℃~105 ℃ (because of material different).Have this as seen, temperature is an important physical amount that characterizes power equipment running state, it is measured have great importance.
Temp measuring method mainly contains two kinds at present: contactless temperature-measuring and contact temperature-measuring.Infrared measurement of temperature is a kind of typical contactless temperature-measuring, and its obvious advantage is a non-contact measurement, does not have the electric insulation problem.But infrared temperature probe must be over against the surface of testee, and maintain a certain distance just with testee and can obtain measured value more accurately, so existing, this method measures blind spot, be not suitable for the measurement of temperature in the enclosed power equipment, and, be difficult to use in multiple spot on-line monitoring simultaneously because cost is higher.Infrared measurement of temperature is subject to the interference of environment and peripheral electromagnetic field in addition, has the not high problem of measuring accuracy.Contact temperature-measuring mainly adopts sensing elements such as thermopair, thermistor and semiconductor temperature sensor.This temp measuring method needs temperature-sensing element directly to contact with electrified body, with plain conductor signal is drawn then, has precision height, advantage that cost is low.But because the point for measuring temperature of power equipment often has very high voltage, sensing element and plain conductor insert the stability that the back influences system easily in this contacting temperature measurement method, introduce unsafe factor.
Another contact temperature-measuring method is to adopt the distributed optical fiber temperature measurement of optical fiber as sensor, be Raman thermometric and Brillouin scattering thermometric and optical fiber grating temperature-measuring, its remarkable advantage is the problem that has solved electric insulation, but exist spatial resolution low in the present circumstance, temperature measurement accuracy is low, shortcomings such as influence factor is many, the temperature measurement accuracy of temperature-measuring system of distributed fibers is subject to the influence of light source fluctuation and fibre-optical bending, fiber bragg grating device is except to the responsive to temperature, it is subjected to physical stress, the influence of extraneous factors such as humidity is bigger, influenced its thermometric precision like this, simultaneously in the occasion that much needs thermometric, the electrical distance compactness, optical fiber needs coiling, influence the safe operation of electric system, the cost of optical fiber temperature-measurement is higher relatively in addition.
Therefore how to overcome the shortcoming of the whole bag of tricks in the present circumstance, propose to be fit to the thermometry of high-voltage charged body, have great importance.
Summary of the invention
The purpose of this utility model is, a kind of temperatures of high-voltage electrified bodies on-Line Monitor Device is provided, and this device can be realized the temperature of safe and reliable on-line monitoring high-voltage charged body.
To achieve these goals, the utility model is taked following technical solution:
A kind of temperatures of high-voltage electrified bodies on-Line Monitor Device is characterized in that, the circuit part of this device mainly includes:
Temperature probe, this temperature probe adopt high-precision low-power consumption thermometric chip, and its temperature-sensitive face is close to tested electrified body;
Photoelectric control/radiating circuit, this photoelectric control/radiating circuit is arranged on the electrification in high voltage side, and it comprises photoelectric cell, and photoelectric cell is connected with operational amplifier, and operational amplifier links to each other with field effect transistor, and field effect transistor connects High Temperature Lithium Cell; The light emitting diode that links to each other with temperature probe in addition;
The Photoelectric Signal Processing unit is used to calculate the temperature that restores tested electrified body, and this Photoelectric Signal Processing unit is arranged on the outside of low-pressure side;
Temperature probe links to each other with photoelectric control/radiating circuit by shielded cable, the light emitting diode of photoelectric control/radiating circuit is connected with the Photoelectric Signal Processing unit by output optical fibre, and the Photoelectric Signal Processing unit is connected with the photoelectric cell of photoelectric control/radiating circuit by input optical fibre;
Receive to photoelectric cell by input optical fibre from the light pulse trigger pip of Photoelectric Signal Processing unit input, control High Temperature Lithium Cell and power up work for the thermometric chip through opening by the field effect transistor of photoelectric control/radiating circuit behind the operational amplifier, the light emitting diode that the electric impulse signal of thermometric chip output drives photoelectric control/radiating circuit produces light pulse signal, to the Photoelectric Signal Processing unit, calculate the temperature that restores tested electrified body by output optical fibre by the Photoelectric Signal Processing unit.
The utlity model has insulation tolerance intensity height, antijamming capability and by force, not being subjected to surrounding environment influence and the interference of electromagnetic field, easy for installation, advantage such as cost is lower, be suitable for the place of different electric pressures, as the current of inside such as switch cubicle, power distribution cabinet, the temperature survey that bus is arranged the different parts such as external insulation of junction contact, cable surface and power equipment.
Description of drawings
Fig. 1 is opto-electronic conversion of the present utility model, control circuit structural representation.
Fig. 2 is a device contour structures sectional view of the present utility model, symbolic representation among Fig. 2: 1 is sleeve, 2 is fibre-optical splice, and 3 is the optical fiber through hole, and 4,5,8 is trip bolt, 6 is insulcrete, 7 is photoelectric control/radiating circuit plate, and 9 is the anode jackscrew, and 10 is battery case, 11,17 is spring, 12 is High Temperature Lithium Cell, and 13 is irdome, and 14 is the high-temperature cable shielding line, 15 is the battery cathode jackscrew, 16 is three core high-temperature cables, and 18 is the thermometric chip, and 19 is temperature probe drain pan (aluminum hull), 20 is temperature probe top cover (aluminum hull), and 21 is the temperature probe circuit board.
Fig. 3 is an insulation securing member sectional view of the present utility model, the symbolic representation among Fig. 3: 31 is temperature measuring equipment, and 32 is circular bus row, and 33 is the teflon securing member, and 34 is the teflon trip bolt.
The embodiment that provides below in conjunction with accompanying drawing and inventor is described in further detail content of the present utility model.
Embodiment
Referring to Fig. 1, temperatures of high-voltage electrified bodies on-Line Monitor Device of the present utility model, the main temperature probe of its circuit part, photoelectric control/radiating circuit, parts such as optical fiber and Photoelectric Signal Processing unit, temperature probe adopts high-precision low-power consumption thermometric chip, its temperature-sensitive face is close to tested electrified body, receive to photoelectric cell by input optical fibre from the light pulse trigger pip of Photoelectric Signal Processing unit input, control High Temperature Lithium Cell and power up work for the thermometric chip through opening by field effect transistor behind the operational amplifier, the electric impulse signal driven for emitting lights diode of thermometric chip output produces light pulse signal, to the Photoelectric Signal Processing unit, can calculate the temperature that restores tested electrified body by output optical fibre.
The temperature-sensing element of temperature probe adopts high-precision low-power consumption digital temperature sensor (temperature-measuring range is-40 ℃~125 ℃), during temperature probe work, the temperature signal of current is converted into the square-wave signal with certain frequency, and the frequency of square-wave signal is directly proportional with the thermodynamic temperature of current to be measured.With the light emitting diode in this square-wave signal driving photoelectric control/radiating circuit, the temperature signal of current finally is modulated into and is light signal like this, through the photoelectricity reception processing unit of Optical Fiber Transmission, calculate the temperature value that restores electrified body by the output characteristics of temperature sensor at last to low-pressure side.Adopt elements such as silicon photocell, field effect transistor to form control circuit in photoelectric control/radiating circuit, be used for receiving the light signal from the emission of photoelectricity processing unit laser instrument, it is in running order or forbid duty to control temperature probe.
The exterior light electric signal processing unit of the photoelectric control/radiating circuit on electrification in high voltage side and low-pressure side is isolated by plastic optical fiber, can effectively realize the isolation between the different potentials, guarantees the security of system works.
The power supply of this temperature measuring equipment adopts high temperature lithium ion battery (operating temperature range is 0 ℃~150 ℃), avoided adopting that influence from current power taking voltage instability when not having electric current system's operation and the current can't power taking and make temp measuring system problem such as can't work, can guarantee the reliability of system works.Because all circuit design all adopt the principle of low power dissipation design in the temperature measuring equipment, current maxima is less than 300 μ A (when the measurement temperature was up to 125 ℃, the source current maximal value of digital temperature sensor consumption was 250 μ A) during the temperature measuring equipment operate as normal.If temperature probe adopts service intermittent (as popping one's head in every 5min work once, working the 5s time) at every turn, and consider the self discharge of battery, so can be to guarantee per one-shot battery (but the bonding apparatus maintenance is changed) of changing more than 4~5 years in good time.The insulation securing member that is used for fixing device for detecting temperature adopts polytetrafluoroethylmaterial material (but heatproof is more than 200 ℃) to process, insulation when satisfying the use of high voltage occasion and temperature tolerance requirement of strength.
(maximum safety temperature that guarantees reliability service as the A class F insulating material F is 105 ℃ when the observed temperature of device reaches the critical maximum permissible temperature of high-voltage charged body, and the long-term maximum operating temperature of metal bolts jointing is 80~105 ℃) time, the Photoelectric Signal Processing unit can also in time provide warning, to remind the operations staff to site inspection.
Among Fig. 2, the sleeve 1 in the utility model, fibre-optical splice 2, battery case 10, temperature probe shell (drain pan 19 and top cover 20) all adopt metallic aluminium to make.Its middle sleeve 1, battery case 10, probe top cover 20, oxidation processes is all passed through on the surface of probe drain pan 19.The negative pole of High Temperature Lithium Cell 12 by spring 11, battery cathode jackscrew 15 with and sleeve 1 connect as one.Like this, sleeve 1 and battery case 10 promptly can be used as the power supply ground of power supply in this device.
During installation, one end of photoelectric control/radiating circuit plate 7 and silicon photocell and the light emitting diode in the fibre-optical splice 2 are welded, the other end respectively with anode jackscrew 9, trip bolt 8 (trip bolt 8 links together with battery case 10), high-temperature cable in three lead-in wires weld.Direction as shown in fig. 1 penetrates the left end of optical fiber from sleeve 1, passes from the right-hand member of sleeve 1, and by vertical trip bolt 4 two-way optical fiber is fixed on the fibre-optical splice 2.Spur the optical fiber that has fixed to the right along the sleeve direction from the left end of sleeve 1, make fibre-optical splice 2, the fixed position that photoelectric control/radiating circuit 7 and battery case 10 arrive in the sleeve 1, and pass through vertical trip bolt respectively with fibre-optical splice 2, battery case 10 is fixed on the sleeve 1.The untapped end of high-temperature cable is passed the through hole of irdome 13, temperature probe top cover 20, cover upper spring 17, burn-on in the end of cable temperature sensor circuit plate 21 and temperature sensor 18 (temperature-sensitive faces down).Bottom at temperature probe drain pan 19 is coated heat conductive silica gel uniformly, and the temperature-sensitive face of temperature probe 18 is imbedded heat conductive silica gel.Screw on temperature probe top cover 20, make spring 17 produce compression set, thereby guarantee that the temperature-sensitive face of temperature sensor 20 is close to the lower surface of probe drain pan 19 by temperature probe circuit board 21 by spring 17.
The shielding line at high-temperature cable 16 two ends closely is connected with battery case 10, temperature probe top shell 20 by trip bolt respectively, all shells and the tested electrified body that have guaranteed this device like this are in equipotential, have avoided the discharge hidden danger that causes owing to current potential is inconsistent.By trip bolt irdome 13 is fixed on the sleeve 1, the battery case 10 of at last High Temperature Lithium Cell 12 being packed into screws on battery cathode jackscrew 15.
Fig. 3 is the scheme of installation that this sensing device is used for measuring switch cabinet bus row contact temperature, by teflon securing member 33 and poly-tetrafluoro trip bolt 34 sleeve 31 is fixed on the tested current (copper bar) 32, uses high temperature gummed tape that temperature probe is tightly pricked simultaneously and be rolled on the tested current 32.
This sensing device temperature-measuring range is (40 ℃~125 ℃), and temperature measurement error is ± 1 ℃.The High Temperature Lithium Cell operating voltage that adopts is 3.67V, and capacity is 1.5Ah, and operating temperature range is 0 ℃~150 ℃.The working current of whole system increases with the rising of dut temperature.When the measurement temperature was 125 ℃, the maximum operating currenbt of temperature probe was 250 μ A, and the working current of whole device is less than 300 μ A at this moment.If temperature probe adopts service intermittent mode (the every 5min work of temperature probe is once worked the 5s time) at every turn, and consider the self discharge of battery, can only need change one-shot battery in per 4~5 years and get final product completely to guarantee sensing device.