High-precision signal processing method for insulation online monitoring of high-voltage electric-power capacitive equipment

Abstract

The invention discloses a signal processing and calculating method for insulation dielectric dissipation factors with the characteristics of high precision and immunity to electromagnetic interference, which developed by aiming at high-voltage electric-power capacitive equipment for realizing insulation online monitoring technology in the equipment life cycle management of an intelligent power grid. In the scheme, based on distributing type remote synchronous signal collection and through carrying out complete-frequency discrete sampling on the leakage current and the busbar voltage of the high-voltage capacitive equipment in a timing way, an infinite impulse response filter group (IIRG) consisting of a point-pass filter, a low-pass filter, a high-pass filter and a necessary point-resistance filter is arranged by aiming at the interference characteristics of high-voltage electric power equipment, input signal sequences adaptive to the time constants of the IIRG are obtained through signal extension, filter output with 50Hz of power frequency signals is obtained through the IIRG, the phasor phase difference of the leakage current and the busbar voltage of the high-voltage capacitive equipment are obtained with a phase algorithm, and further the insulation dielectric dissipation factors with high precision are obtained.

Description

technical field [0001] The invention relates to insulation on-line monitoring of high-voltage power capacitive equipment, and belongs to the field of state maintenance and on-line monitoring of high-voltage power equipment and the field of monitoring and management of the entire life cycle of equipment in smart grids. Background technique [0002] The power industry is the main body of the energy industry. Ultra-high voltage and ultra-high voltage transmission can achieve longer-distance and higher-efficiency energy transmission. High-voltage insulation technology is the key technology. The vast majority of faults in UHV and EHV power grids manifest as insulation damage. The high-voltage power equipment other than the transmission line is concentrated in the substation, including the main transformer, high-voltage circuit breaker, current transformer (CT), capacitive voltage transformer (CPT), bushing, coupling capacitor, lightning arrester, etc. Most devices are capacitive...

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Problems solved by technology

The capacitive equipment is high-voltage equipment, there are a lot of high-voltage flashovers and discharges on site, the electromagnetic interference is very serious, and the sampling signal contains a large number of interference signals; monitoring the insulation of the capacitive equipment requires the leakage current signal and the equipment voltage signal of the equipment, the latter The location of the sensor (potential transformer) is far away from the capacitive equipment. If the leakage current signal of the capacitive equipment is transmitted to the electronic equipment through the cable connection and then measured for a small leakage current, a large number of errors and interference signals will be further entered. This makes the scheme difficult to be practical, and the measurement results lack credibility

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