Three-phase four-wire system zero-line failure and open-phase intelligent protector

Abstract

The invention discloses a three-phase four-wire system zero-line failure and open-phase intelligent protector. The outputs of a current transformer and a voltage transformer are connected to the input of a range switching module; the range switching module, a data processing module, a CPU logic controller and a drive circuit are connected with each other in sequence; one output switch trip signalof the drive circuit is connected with a switch with an opening coil, and the other output alarm signal is connected with a background management center; and the CPU logic controller is connected with a remote management center or terminal through a communication module. The invention can be used for directly judging whether the zero line goes wrong and transmitting a protection control signal after the failure occurs, so that the switch trips to cut off the failure rear-end power circuit, thereby achieving the goal of protecting equipment and personal safety. Meanwhile, an alarm signal is transmitted to the background management machine to carry out the corresponding treatment, thereby realizing the function of alarm report; and the failure information can quickly make decisions for treating the power-off accident, thereby shortening the power-off time.

Description

[0001] technical field [0002] The invention relates to a three-phase four-wire zero line fault and phase-loss intelligent protection device. The device can automatically detect whether the zero line is faulty and handle different fault situations, and belongs to the technical field of power supply. [0003] Background technique [0004] In the low-voltage power supply and distribution systems of urban and rural areas and factories and mines in my country, most of them use 380 / 220V three-phase four-wire mixed low-voltage power supply systems, such as figure 1 shown. This hybrid three-phase four-wire low-voltage power supply system will produce single-phase load distribution and unbalanced distribution problems, and there will be unbalanced phase-to-phase voltages. In urban public power distribution rooms, most of the loads of distribution transformers are single-phase loads, even more than 80%, which will inevitably lead to unbalanced load distribution between phases. ...

AI Technical Summary

Problems solved by technology

[0012] Although there are currently many technologies that use the network for real-time monitoring, it is difficult to implement for 0.4kv distribution network terminals. Communication is difficult. For a city's distribution network power supply line system, it is a very huge project to distribute the monitoring network to each line terminal

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