Study on Ultraviolet Detection System to High-voltage Discharge
|School||Tohoku Electric Power University|
|Course||High Voltage and Insulation Technology|
|Keywords||High-voltage Discharge UV Sensor Lens Coupling PMT VirtualInstrument|
The main cause for the insulation deterioration of electrical equipment is thehigh-voltage discharge. Statistics shows that the insulation accidents are in the secondplace among all the incidents of power system.They can have a wide range ofinfluences, a power failure for a long time and a huge economic losses.They alsodirectly threaten the safe and stable operation of the power system. Therefore,it has avery important practical significance for detecting the high-voltage discharge ofelectrical equipment.The traditional method for detecting the high-voltage discharge generally useselectrical detecting method,which has the disadvantage of the strong electromagneticinterference at work-site and the low sensitivity. On the basis of analyzing extensiveliterature at home and abroad on detecting ultra-violet(UV) light, this paper proposesmeasuring the sun-blind UV light to realize real-time detecting discharge,anddescribes the implementation method of hardware and software to the test system.Thehardware design includes the design of the UV sensor and the related electriccircuits.Through the analysis of spectral characteristics for the UV sensor,we know itsoutput approximately linear to the sun-blind UV light,and it will not respond to theother wavelengths light. The design of the electric circuits mainly focuses on twoaspects,which are the operation stability of photomultiplier tube(PMT) and theprocessing of optical signal.We also design PMT voltage divider circuit and thehigh-voltage output circuit with low ripple noise,so that PMT can get a reliable gainwithout being interfered by ripple noise. The processing circuit for optical signalincludes the current-voltage (I/U) conversion and the filter-amplifier circuit.Thedetecting system uses LabVIEW to collect signals,and designs the login screen, themain interface, data acquisition, data storage and digital filtering module. We test thedetecting system by simulating the detection experiments of the high-voltagedischarge in laboratory.As the test result shows, the detection system basically meetsthe design requirements,and has a good sensitivity and a strong anti-interference ability. It also has the potential to be used for online real-time monitoring of highvoltage discharge.