Wire microcomputer protection device based inrush discrimination technology

Abstract

The invention discloses a wire microcomputer protection device based on an inrush discrimination technology. A current-loaded current transformer of a charging line is connected with an alternating current sampling module; the alternating current sampling module and a power module are both in bi-directional connection with a CPU (central processing unit) management module; the CPU management module is respectively in bi-directional connection with an input / output module and a man-machine interaction module; a CPU protection module comprises an A / D analog-to-digital conversion module and a digital signal processing module; and the CPU management module is connected with the A / D analog-to-digital conversion module and the digital signal processing module in sequence. The device can obviously improve the accuracy rate of wire protection operation and the power supply reliability of medium-low-voltage networks.

Description

technical field [0001] The invention relates to a line microcomputer protection device using surge current identification technology. Background technique [0002] At present, there are a large number of distribution transformers installed on medium and low voltage lines. At the moment of switching on, the excitation inrush currents generated by each transformer are superimposed on the line and reflected back and forth, resulting in a complex electromagnetic transient process. When the system impedance is small, it will The larger inrush current occurs, the time constant is also larger. For the current quick-break protection in the two-stage current protection, due to the need to take into account the sensitivity, the operating current value is often made smaller, especially when the line is long or the system impedance is large. The excitation inrush current value may be greater than the device setting value, causing the protection to malfunction. This situation is not pr...

AI Technical Summary

Problems solved by technology

[0003] In recent years, with the rapid growth of regional electricity loads, the number of distribution transformers on medium and low voltage lines has increased. At the moment of hand-on and coincidence, due to the inrush current of distribution transformers, the load current often approaches or even reaches the action value of current quick-break protection. The medium and low-voltage line protection that cannot identify the inrush current has gradually become unreliable

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