Current measurement device and method facing three-phase four-wire system balanced load

Abstract

The invention relates to a current measurement device and method facing a three-phase four-wire system balanced load, and belongs to the field of measurement. A rectangular stop block is fixedly connected with one end of a threaded guide rod, the other end of the threaded guide rod is sleeved with a manual rotating handle, a U-shaped frame is in threaded connection with the threaded guide rod, a linear motor is fixedly connected with the U-shaped frame through a motor supporting base, a sensor module is arranged in a sensor adjusting table, the lower end of the sensor adjusting table is fixedly connected with two slidable keys, a pair of linear keyways are arranged in the U-shaped frame, the linear motor drives a threaded lead screw to rotate, the threaded lead screw is provided with two-directional threads and can drive a nut arranged on the threaded lead screw to do reciprocating motion, and the nut is connected with the sensor adjusting table through a screw. Accordingly, an effective value of a three-phase alternating-current current connected with the balanced load can be measured in a passive and non-contact mode, and the device has the advantages of being small in size, simple in structure, low in cost, wide in application range and the like.

Description

technical field [0001] The invention belongs to the measurement field, and relates to a passive and non-contact current effective value measuring device and method for three-phase four-wire symmetrical loads. Background technique [0002] With the increasing use of information, communication technology (ICT) devices and household appliances, the detection of power consumption has become more and more important. Current is one of the main parameters of power systems, and the measurement of current is a basic And it is a very important task. With the widespread use of electrical appliances with symmetrical loads such as three-phase motors, three-phase electric furnaces, and three-phase transformers, it is becoming more and more difficult to design a current sensor for three-phase four-wire symmetrical loads. It is becoming more and more important. The frequency of three-phase alternating current in my country is basically fixed at 50Hz. The effective value of alternating current...

AI Technical Summary

Problems solved by technology

Current measurement mainly uses current transformers based on the principle of electromagnetic induction. It is mainly based on the principle of transformers, and the iron core and windings are connected in series to the measurement circuit to achieve current measurement. However, this type of sensor is due to its magnetic flux saturation. It is easy to distort the measurement and make the measurement inaccurate. At the same time, the saturation of the magnetic flux will easily increase the core loss, generate high heat and damage the insulation layer, causing safety problems. At the same time, its cost increases exponentially with the increase of the measured current level. These electromagnetic currents The disadvantage of the transformer is caused by its structure, which cannot be changed

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