High-voltage electrical appliance insulation parameter on-line monitoring method based on reference phase method

Abstract

This invention relates to an on-line monitoring method of high-pressure electrical apparatus insulation parameters based on preference phase method, which comprises data collection, data process and analysis and diagnose decision-making. The online monitoring system is divided into two categories: integral online monitoring system and distributed online monitoring system which is mainly monitor the dielectric loss and constant capacitance of capacity apparatus. It is characterized by adopting reference phase method and locating sensors used for collecting reference phase signals in each monitoring unit. This invention avoids the long distance transmission of PT secondary voltage signals and can ensure both the accuracy of insulation parameters measuring and increase the safety reliability of the system; it adopts reference phase to increase the measuring accuracy of insulation parameters; it eliminates all impacts generated by absolute angle errors of the sensor itself on the insulation parameter measuring with high application values.

Description

1. Technical field: [0001] The invention relates to on-line monitoring of insulation of high-voltage electrical equipment, more specifically to an on-line monitoring method of insulation parameters of high-voltage electrical equipment based on a reference phase method. 2. Background technology: [0002] Due to the influence of factors such as electric field, conductor heating, mechanical force, chemical corrosion and environment, the insulation performance of power transformers, current transformers, lightning arresters and other high-voltage electrical equipment in the power system will inevitably gradually deteriorate during long-term operation. , and even lead to equipment failure, threatening the safe operation of the power system. Therefore, in order to ensure the safe and reliable operation of the power system and minimize the accident rate, it is necessary to conduct real-time insulation on-line monitoring of the insulation status of high-voltage electrical equipment,...

AI Technical Summary

Problems solved by technology

[0008] In practice, one voltage transformer and several capacitive devices are usually installed on the same bus in a substation. Therefore, in order to be able to monitor the insulation parameters of all capacitive devices online, the traditional method is to use multiple shielded cables Lead the secondary side voltage signal of the PT to the monitoring unit of each capacitive device for corresponding processing, but this will bring many disadvantages

First of all, for substations with a voltage level of 110kV and above, because the distance between different devices is relatively long, the analog signal needs to be transmitted over a long distance in the complex electromagnetic environment of the substation, and it is easy to introduce a large amount of electromagnetic interference, causing Signal distortion, so the PT secondary voltage signal, that is, the reference voltage signal for calculation, is prone to distortion during long-distance transmission, which affects the measurement accuracy of the dielectric loss factor of capacitive equipment and causes misjudgment of faults

Secondly, long-distance cable laying will also increase the probability of cable ground faults, which will affect the safe and reliable operation of the system.

Furthermore, since the number of capacitive equipment in a substation usually accounts for more than 40% of the total electrical equipment in the substation, if the traditional monitoring method is used, a large number of cables need to be laid, which not only increases the complexity of the system, but also Increased the amount of construction on site

In addition, if the main wiring of the primary equipment of the substation is changed, for example, when some capacitive equipment is added or removed, the problem of laying or removing the cables for transmitting voltage signals will occur, which not only increases the difficulty of on-site construction, but also imposes a burden on the operation department. Daily work brings some trouble

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