Summary of the invention:
The present invention provides a kind of resistance ratio cable fault test to overcome drawbacks described above existing in the prior artInstrument.
To solve the above problems, resistance ratio electric cable failure detector proposed by the present invention, comprising: cabinet, the cabinetThere are liquid crystal display, keyboard above；Voltage signal generator, high-accuracy voltage sampler, high-precision cipher telegram are internally integrated in cabinetFlow sampler, signal amplifier, A/D converter, measurement loop control unit, CPU processor, data storage, display unit；ItsIn, measurement loop control unit is connected with high-accuracy voltage sampler, and high-accuracy voltage sampler is connected with signal amplifier, signalAmplifier is connected with A/D converter, and high-accuracy current sampler is connected with signal amplifier, signal amplifier and A/D converterIt is connected, CPU processor is single with voltage signal generator, measurement loop control unit, A/D converter, data storage, display respectivelyMember, keyboard are connected, and display unit is connected with liquid crystal display.
Preferably, the resistance ratio electric cable failure detector further includes that voltage signal generator, high-accuracy voltage takeSample device, high-accuracy current sampler export test voltage signal in a cable wherein good phase line by voltage signal generatorIn failure phase line, this two phase lines end is connected into short circuit.
Preferably, the resistance ratio electric cable failure detector, voltage, current sampler and measurement loop control unit areVoltage bridge formula balancing circuitry or resistance test circuit.
Preferably, the resistance ratio electric cable failure detector, test scope: 10V~110KV cable.
Preferably, the resistance ratio electric cable failure detector, instrument power supply system alternating current-direct current and included battery supplyElectricity.
Preferably, the resistance ratio electric cable failure detector, voltage signal generator can also be constant current source generator.
Preferably, the resistance ratio electric cable failure detector, the sliding end of voltage or current signal input potentiometer,Sliding end is adjusted to be allowed to balance with the both ends of test failure cable.
The present invention measures loop control unit according to CPU after voltage signal generator is to one test signal of cable faultProcessor instruction selects circuit to get test signal for high-accuracy voltage sampler, high-accuracy current sampler, will test signalIt is conveyed to signal amplifier to amplify, then exports and give A/D converter change data, data give input CPU processor analysis, willTest data is saved in data storage, while being exported to display unit, in liquid crystal display screen display.
The principles of science based on the technical program:
Coaxial cable A, B, C phase line resistance is almost equal, and error can be ignored, faulty by not having in coaxial cablePhase line (hereinafter referred to as: relief cable) is connected with failure phase line end, a voltage is added between relief cable and failure phase line, justHaveWherein, L, R1 and R2 can measure to obtain, such as figure two, so
The present invention: calculating failure cable phase line resistance ratio, converses Method of Cable Trouble Point distance, i.e. resistance ratio cable eventHinder tester.
The present invention has the advantages that compared with prior art and advantage:
The present invention converses Method of Cable Trouble Point distance, and this measurement according to failure cable phase line resistance ratio is calculatedMethod is not influenced by factors such as the length of cable, capacity, type, running environment, can accurately test out fault point distance, instrumentPerformance is stable, easy to operate, to electricity when can effectively solve because of overlength degree, large-sized cable generation high resistive fault, leakage failureCable fault point distance measurement causes difficulty and because the factors such as failure type of cable, cable fault property, running environment can not be measuredMethod of Cable Trouble Point apart from the problems such as.
Specific embodiment:
With reference to the accompanying drawing and specific example, the present invention is furture elucidated, it should be understood that these embodiments are merely to illustrate thisIt invents rather than limits the scope of the invention, after the present invention has been read, those skilled in the art are to of the invention variousThe modification of equivalent form falls within the application range as defined in the appended claims.
As shown in Figure 1, resistance ratio electric cable failure detector, including cabinet, have above the cabinet liquid crystal display 3,Keyboard 2 is internally integrated voltage signal generator 4, high-accuracy voltage sampler 7, high-accuracy current sampler 9, signal in cabinetAmplifier 8, A/D converter 11, measurement loop control unit 10, CPU processor 5, data storage 1；Tester passes through display keyParameter inputs to CPU processor 5 before disk 2 sets test, and CPU processor 5 sends instructions to the control of voltage signal generator 4Part, voltage signal generator 4 export a test voltage signal to failure cable, and CPU processor 5 controls measure back simultaneouslyRoad controller 10 needs to select different test loops according to calculating, each test loop by high-accuracy voltage sampler 7,The data that high-accuracy current sampler 9 measures, the amplification test signal of input signal amplifier 8, input a/d converter 11, conversionTest result is passed through at CPU processor 5 is exported after digital signal after CPU processor 5 is handled according to measuring and calculation mathematical expressionDisplay unit 6 shows on liquid crystal display 3, meanwhile, test result data will be saved in data storage 1, wait testerMember's call instruction.
Finally, it is stated that the above examples are only used to illustrate the technical scheme of the present invention and are not limiting, although referring to compared withGood embodiment describes the invention in detail, those skilled in the art should understand that, it can be to skill of the inventionArt scheme is modified or replaced equivalently, and without departing from the objective and range of technical solution of the present invention, should all be covered at thisIn the scope of the claims of invention.