Three-phase alternating voltage phase sequence monitoring system

Abstract

The invention provides a three-phase alternating voltage phase sequence monitoring system, including: a step-down filtering and shaping circuit; a comparator circuit which compares a three-phase alternating voltage processed by the step-down filtering and shaping circuit with a reference voltage and outputs a three-channel comparison result; a logic circuit which detects a phase sequence of the three-phase alternating voltage according to the three-channel comparison result and outputs a judgment signal; a driving protection circuit which drives a relay according to the judgment signal; and a relay which generates an indication signal according to an output signal of the driving protection circuit, outputs a phase sequence correct indication signal when the phase sequence of the three-phase alternating voltage is correct, and outputs an alarm indication signal when the phase sequence of the three-phase alternating voltage is in disorder or a phase loss occurs. The three-phase alternating voltage phase sequence monitoring system provided by the invention detects the phase sequence of the three-phase alternating voltage, thereby driving the relay, and protecting safety of electric equipment, and effectively avoiding unnecessary loss brought by the problems of phase sequence disorder and phase loss; and at the same time, since the three-phase alternating voltage phase sequence monitoring system is integrated in a circuit module of a chip, the system is small in size, and the system is convenient to operate and high in detection precision.

Description

technical field [0001] The invention relates to the field of electricity safety, in particular to a three-phase AC voltage phase sequence monitoring system. Background technique [0002] The phase sequence of three-phase AC includes positive sequence, negative sequence and zero sequence. When three-phase AC is applied, the phase sequence plays an important role in the safe operation of equipment in the fields of electricity, electronics, instrumentation, automatic control and power electronics, and often requires detection and judgment Whether the phase sequence of the three-phase AC power supply is correct and whether there is a phase loss problem. If the phase sequence is wrong or there is a phase loss, it is necessary to protect the devices in the circuit in time to avoid damage to the devices. When the three-phase photovoltaic grid-connected inverter is connected to the grid, if the phase sequence of the inverter and the grid are inconsistent, it will cause a large inrus...

AI Technical Summary

Problems solved by technology

[0006] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a three-phase AC voltage phase sequence monitoring system, which is used to solve the problem of large volume, low accuracy and poor operation of the three-phase AC voltage phase sequence detection circuit in the prior art. Complicated issues

Images