Multifunctional three-phase electric power instrument with multiple harmonic measurement

Abstract

The invention discloses a multifunctional three-phase electric power instrument with multiple harmonic measurement, and the instrument employs a three-terminal isolation design of sampling voltage andcurrent input, transmitting output and communication, and a power supply, is strong in anti-interference capability, and is high in safety coefficient. The instrument can measure various electric quantity parameters, especially total harmonic content measurement and multiple harmonic measurement which are not possessed by most of the existing instruments; the instrument has a dual-MODBUS RTU communication function or an optional single-MODBUS RTU communication function and an MODBUS TCP communication function, so the instrument can be conveniently integrated with a system for batch management; the instrument has a double-path transmission function, can realize transmission output of various electric quantity measurement parameters and flexible transmission parameter setting, and can adaptto various transmission application occasions; the controller is provided with two paths of alarm relay output, and the alarm mode can be independently set to meet the application in different alarmoccasions; the instrument has a convenient and rapid calibration process, and is beneficial to rapid batch calibration of instruments. The instrument is provided with a human-computer interface whichis simple to operate, and parameter setting is simple and convenient.

Description

technical field [0001] The invention relates to the technical field of industrial automation measurement and control, in particular to a multifunctional three-phase power meter including multiple harmonic measurement. Background technique [0002] Most of the current industrial three-phase power meters do not have the function of harmonic analysis, but in practical applications, generators are widely used in factories, and it is difficult to make the three-phase windings of generators absolutely symmetrical, which will introduce harmonics. In the process of power transmission and distribution, the power transformer is the main source of harmonics in the process of power transmission and distribution. Since the design of the transformer needs to consider economy, the magnetization curve of its iron core is in a nonlinear saturation state, so that the magnetization current during operation It is a peak-shaped waveform, thus generating odd harmonics; the main source of factory ...

AI Technical Summary

Problems solved by technology

When the circuit breaker breaks the current with high harmonic content, the breaking capacity of the circuit breaker will be greatly reduced, causing arc reignition, short circuit, and even explosion of the circuit breaker

[0008] In addition, due to the existence of harmonics, it is easy to cause various protection and automatic devices of the power grid to malfunction or refuse to operate, and to generate audio frequency interference in the communication system, which will threaten communication equipment and personal safety in severe cases.

Images