Partial-discharge photoelectric detection system and method based on laser diode

Abstract

The invention relates to the technical field of partial-discharge monitoring and specifically relates to a partial-discharge photoelectric detection system and method based on a laser diode. The system includes a photoelectric measurement module, an optical-fiber transmission device, a photoelectric conversion device and a data acquisition device. The photoelectric measurement module is arranged a high-voltage end of a sample. Partial-discharge current undergoes voltage division through a sampling resistor of an appropriate size and flows past the laser diode with a tail fiber. A voltage-sensitive resistor, a bidirectional inhibiting diode and protective resistors form a protection circuit to prevent high-current damages of the diode. The laser diode emits light of different intensities according to difference of the intensities of the partial-discharge currents. Output of the photoelectric measurement module is transmitted through an optical fiber. The photoelectric conversion device converts optical signals transmitted by the optical fiber into electrical signals which are then transmitted to the data acquisition device. The invention provides the device and the method for effective measurement of partial-discharge current of electrical devices; and the measurement result is directly observable, the fiber-entering power is high, the modulation speed is high and the response speed is high and electromagnetic interferences and ground-wire interferences can be effectively prevented.

Description

technical field [0001] The invention relates to the technical field of partial discharge monitoring, in particular to a laser diode-based partial discharge photoelectric detection system and method. Background technique [0002] The high-voltage electrical equipment in the power system will inevitably have certain insulation defects during long-term operation, and partial discharge has become an important cause of equipment insulation degradation. There are often some weak points in the insulation of electrical equipment. Under the action of external voltage, the insulation defect will first discharge, which is the partial discharge of electrical equipment. Although the discharge energy is very weak and does not affect the short-term insulation strength of the equipment, it will cause insulation aging over time and may eventually lead to breakdown of the entire insulation under normal voltage, causing accidents. Regular detection of partial discharge of equipment can detect...

AI Technical Summary

Problems solved by technology

The main disadvantage of this detection method is that it is impossible to determine the amount of discharge. Even if the transmission path between the power point and the sensor remains unchanged, the signal amplitude measured by the ultra-high frequency method and the apparent discharge amount measured by the pulse current method There is also no clear linear correspondence, which increases the difficulty of applying this method for partial discharge calibration, and is a non-electrical measurement method.

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