Leakage protector with phase line switching function

Abstract

The invention discloses a leakage protector with a phase line switching function, which comprises a current transformer and a three-phase current detection circuit. The current transformer is used for detecting leakage current and outputting a leakage signal. The output end of the current transformer is connected with an amplifying circuit, and the amplifying circuit amplifies the leakage signal and inputs the signal into a single chip. The current detection circuit is connected with a current signal receiving circuit, a three-phase current signal receiving circuit inputs a current signal into the single chip, the current signal receiving circuit is used for receiving a three-phase current signal, the output end of the single chip is connected with a driving circuit in driving connection with a switch in a three-phase line, the driving circuit is connected with the input end of the single chip through a feedback circuit, the feedback circuit inputs a driving signal of the driving circuit into the single chip. The leakage protector with the phase line switching function can perform automatic switching according to the load situation between three phases so as to balance current among the three phases, reduces the harm caused by imbalance of the current among the three phases, enables a power grid to be operated stably, and improves power supply quality.

Description

[0001] technical field [0002] The invention relates to a novel multifunctional earth leakage protector. Background technique [0003] In the low-voltage distribution network, the transmission line generally adopts a three-phase four-wire system. In the power supply system of urban residents and rural power grids, because most of the power users are single-phase loads or mixed single-phase and three-phase loads, and the loads are different and the power consumption time is different, so there must be a gap between the three phases of the power grid. unbalanced current. Unbalanced current will increase the power loss of lines and transformers, reduce the output of transformers, and easily cause unbalanced three-phase voltage. The leakage protectors on the market only have basic protection functions such as leakage, overcurrent, short circuit, overvoltage and undervoltage. This type of leakage protector cannot intelligently switch between phase lines, resulting in the ab...

AI Technical Summary

Problems solved by technology

This type of leakage protector cannot intelligently switch between phase lines, resulting in the above-mentioned problems still existing in practical applications

Moreover, the existing leakage protectors all use electromagnetic relays. This kind of mechanical contact switch will spark during use. It is easy to oxidize after long-term use or in harsh environments, which will cause the protection action to not be triggered stably.

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