The charged detection of high-voltage transmission line insulator detects inferior insulator timely and accurately, to safe operation of power system, avoids the tremendous economic loss that epochmaking meaning is arranged.Whether at present the detection means used of power department is all little desirable, and wherein the more detection means of usefulness has short circuit fork measuring staff, according to spark gap concepts, discharge with sparking distance and to judge the insulator quality.Though this measuring method is convenient, is subjected to atmospheric conditions and artificial factor easily, owing to be that non-quantitative is measured, error is bigger, and is unreliable.Measurement means such as Photoelectric Detection bar, resistance capacitance bar are also arranged in addition, but inconvenient operation is all arranged or use unsafe shortcoming, be not suitable for site work.A kind of meter was arranged in recent years, the voltage dividing potential drop at insulator two ends after electronic circuit is handled again shows, though this meter has certain precision, but metering circuit and display device are all complicated at upper end, the device of insulating bar, too heavy, the pointer-type demonstration is difficult for reading, uses still inconvenient.
Goal of the invention of the present utility model is to design a kind of new poor quality insulation.Detector, must possess in light weight, volume is little, and is safe and reliable, make things convenient for characteristic of accurate, make it to be fit to test site and generally use.
In order to realize such goal of the invention, we have designed the ultrasound wave inferior insulator detector that utilizes ultrasound wave to transmit signal, by high-voltage probe, hollow insulating bar and receiving trap are formed, high-voltage probe is contained in the upper end of hollow insulating bar, transmitting transducer is equipped with in its bottom, and receiving transducer is equipped with in the lower end of hollow insulating bar, and receiving transducer links to each other with receiving trap by stube cable.Transmitting transducer in the high-voltage probe converts electrical energy into acoustic energy, the ultrasound wave that produces is sent to receiving transducer by the air in the insulation tube, receiving transducer is converted to electric energy with acoustic energy, by stube cable electric signal is sent to receiving trap after treatment, and result's numeral shows or reports to the police.
Fig. 1 is the diagrammatic cross-section of high-voltage probe.Two electrodes of high-voltage capacitance, top electrode 1 and bottom electrode 9 place the probe top, and an insulation course is arranged between two electrodes, be connected as a body with insulation crust 3, and the size of its thickness decision voltage breakdown and electric capacity, the length of insulation crust 3 is decided by creeping discharge voltage.Respectively there is a probe aperture 2 at the two ends up and down of probe, and probe can be fixed on the probe aperture with screw.Space in the middle of the probe just in time is designed to battery case 5, is used to place battery.Signal wire 4 connects bottom electrode 9 and emitting electrons wiring board 7, the voltage signal of being surveyed arrives electronic circuit board 7 by signal wire 4, input signal as the radiating portion circuit, radiating circuit is modulated into pulse duration frequency signal to tested electric signal, is converted to ultrasound wave by the transmitting transducer 8 that places the probe bottom.Metal shell 6 is arranged as shielding box in the outside of electronic circuit 7, transmitting transducer 8, good shield effectiveness is arranged.
Fig. 2 is the wiring diagram of radiating portion.Primary voltage be by one that obtains after high-voltage capacitance and the divider resistance series connection dividing potential drop with the linear low-voltage signal of high pressure, through precise rectification circuit output half-wave rectification signal, obtain a DC voltage that ripple is minimum through active low-pass filter again, launch with hyperacoustic form through transmitting transducer again through the pulse duration frequency signal that the v/f conversion produces.The multivibrator that the generation of ultrasonic frequency constitutes by means of 555 timers, this frequency changes along with tested voltage.Frequency is also high when tested voltage is high, and when tested voltage was low, frequency also descended thereupon, and both remain good linear relationship.
The ultrasound wave that transmitting transducer produces is sent to the receiving transducer that is contained in hollow insulating bar lower end by hollow insulating bar.Receiving transducer is converted to electric energy with acoustic energy, and by stube cable electric signal is sent to receiving circuit.Because the signal that receiving transducer sends is faint, and be accompanied by some undesired signals, therefore also must handle signal by receiving circuit, be reduced into actual frequency signal clearly through amplification, frequency-selecting, shaping, carry out the f/v conversion again, last output voltage signal obtains the real voltage reading of high-pressure side through conversion.Fig. 3 is the wiring diagram of receiving circuit, input signal is the pulse duration frequency signal of sending here from receiving transducer, field effect transistor in preposition low discharging circuit is tentatively amplified, put through height again and with bandwidth-limited circuit the simple amplitude of signal is amplified and suppress other undesired signals, through restoring circuit the ultrasonic pulse sequence of the higher-order of oscillation is reverted to full sized pules then, with in addition shaping of waveform, convert DC voltage to through f/v through a monostable trigger again, send into and show and warning circuit.Circuit board for receiving is made in the receiving trap, and digital demonstration and hummer are all on table.In order to check out inferior insulator more quickly and effectively, can be designed to just often send chimes of doom, when voltage during less than certain limit, as≤4KV or≤during 3KV, then alarm free sound can be exchanged into numeral and shows, reads test data accurately.
High-voltage probe of the present utility model is reasonable in design, compact conformation, and volume is little, uses lightly, is convenient to execute-in-place.The high-pressure side measuring-signal is sent to low pressure end with ultrasound wave, and receiving trap is not electrically connected between the high and low pressure side at low pressure end.Adopt direct-reacting digital to show and audible alarm, both can detect inferior insulator, can measure the insulator chain Potential distribution again, safe ready, accurately and reliably, practicality is very strong.