A passive voltage remote monitoring system for capacitive voltage division

Abstract

The invention discloses a passive voltage remote monitoring system for capacitor voltage dividing and power taking, including sampling capacitor, sensor A, detector, sensor B, working power supply, central processing unit, communication module, current transformer and monitoring module. The sampling capacitor is connected to sensor A and collects voltage from the power grid. It transmits signals to the central processor through the detector and sensor B for data analysis and transmission to the communication mode. The central processing unit is connected to sensor B, and sensor B sends out current through current mutual inductance The device provides power, and the working power is connected with the communication module and the monitoring module, and takes electricity from the energy storage circuit of the monitoring module to provide power for the communication module. The circuit distribution design of the present invention enables the monitoring system to directly draw power from high voltage to supply power for the operation of components, without secondary power supply, and is suitable for passive voltage online monitoring in the power system by capacitor voltage divider.

Description

technical field [0001] The invention relates to a monitoring system, in particular to a passive voltage remote monitoring system for capacitive voltage division and power acquisition. Background technique [0002] At present, the main methods of power acquisition are: high-voltage induction power acquisition and PT power acquisition. High-voltage induction (small CT), the premise is to make a metal ring on the contact arm or busbar, and fix it on the high voltage as a metal ring, which will cause the following disadvantages: [0003] 1. Since it is installed on the originally smooth bus bar or contact arm, the electric field distribution is changed, causing changes in insulation and dynamic and thermal stability; [0004] 2. Generate eddy current, which is one of the main factors that cause the temperature rise of the switch cabinet; [0005] 3. The load of the power system changes greatly, and the bus current varies greatly (several amperes to thousands of amperes), and t...

AI Technical Summary

Problems solved by technology

[0005] 3. The load of the power system changes greatly, and the bus current varies greatly (several amperes to thousands of amperes), and the instantaneous current of the bus short circuit can exceed ten times the rated current

Resonant overvoltage causes PT saturation, and the secondary voltage of PT has changed. At this time, it will take a long time for the microcomputer resonance elimination device to complete all actions. The time to eliminate resonance is generally 1-2 seconds, and the start-up time of the protection device is much faster. In order to eliminate the resonance time, it may cause the protection device to malfunction

In addition, due to the long time for eliminating resonance, the PT cannot withstand the impact of excitation overcurrent for a long time, resulting in PT damage accidents

Even if the microcomputer harmonic elimination device is installed, PT explosion accidents often occur, and the cost of PT power supply is high, so the way of small PT power supply is also an unreliable way

[0013] To sum up, it can be seen that taking power through the above ways of taking power and analyzing abnormal working conditions of the power grid not only poses a threat to the safe operation of the power grid, but also is prone to adverse consequences such as false alarms

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