Improvement of DC power distribution with open hall current sensor

Encore Hua Nan

Abstract ： According to the principle of open-ended Hall current sensor 、 Features and installation methods , This paper analyzes the application of open-ended Hall current sensor in DC distribution transformation , Quickly realize the intelligent transformation of DC distribution system .

key word ： Open type Hall current sensor ; DC distribution system ; reform

0： summary

DC distribution system is usually composed of high-frequency switching power supply and battery , Used to control... In DC system 、 The signal 、 Automatic relay protection device 、 Provide reliable DC current power supply for emergency lighting , The reliability of its power supply 、 There are high requirements for stability and power supply quality . Therefore, it is very important to reform some DC distribution systems with long service life .

1： The open type Hall current sensor assists the transformation of DC power distribution

1.1  Modification requirements

The system transformation requires that the DC system shall be switched without power failure , That is, the load can be poured out and into without losing the DC power supply , The reconstruction project is difficult . For this demand , Open type Hall current sensor can be used to solve the problem of DC current measurement in the reconstruction project , Ensure that the DC bus and DC load are not powered off and operate safely during the transformation .

1.2 Technical characteristics and working principle of the open-ended Hall current sensor

The open-ended Hall current sensor consists of a housing 、 Iron core 、 Sampling circuit board and fixed resin , With high temperature resistance 、 High mechanical strength 、 Environmental protection and other characteristics ; The circuit board and external wiring adopt green pluggable terminals , Convenient field wiring .

The open-ended Hall current sensor is a modification of the traditional open-loop Hall current sensor , According to the principle of Hall effect and electromagnetic induction , Primary side current IP The resulting magnetic field , After magnetization through the magnetic core , The hall sensor chip is used to induce the primary side current at the air gap of the magnetic core IP The size and direction of . Output voltage of Hall sensor chip , Through the signal processing circuit , The output of the sensor can reflect the measured current . In order to improve the performance of hall open-loop sensor , Silicon steel or permalloy is usually used as the material of magnetic core .

 

Schematic diagram of open-ended Hall sensor

1.3 Application example

A railway locomotive renovation project , The transformation requires that the sensor be connected to monitor the DC current of the busbar without dismantling the busbar , In this case, only open-ended Hall current sensors can be used , Convenient on-site installation .

The field installation is shown in the figure below , If the power can be cut off for installation on site , Two corresponding threaded holes can be opened on the copper bar according to the requirements of sensor spacing , Fix the sensor on the threaded hole of the busbar through the mounting and fixing hole at the rear , Complete the sensor installation ; If the site requires continuous power installation , The matching rubber cushion block can be embedded between the shell and the copper bar for fixation , Ensure that the sensor can work reliably under vibration conditions , The whole installation process is relatively fast and simple .

 

Installation drawing of a railway locomotive renovation project

2：  Open type Hall current sensor

     

The open type Hall current sensor is compared with the closed type Hall current sensor , And traditional single iron core 、 The design of single Hall chip is different , To be designed as a split structure , Separate and install the iron core symmetrically , The hardware adopts the parallel complementary differential input of double hall chips , It has stable performance 、 High mechanical strength 、 High permeability , The circuit board and external wiring adopt green pluggable terminals , Convenient field wiring .

 

AHKC Series open-ended Hall current sensor

3： Conclusion

From the perspective of transformation cost , For example, the traditional closed-end Hall current sensor or shunt scheme is adopted , During construction, the DC bus copper bar shall be removed first , Then install the sensor , Then reinstall and restore the busbar , Power failure cooperation is required for rectification of lines , The open type Hall current sensor is more time-saving and labor-saving ; From the aspect of test performance , As long as the upper part of the sensor is installed 、 The lower body screws are fixed tightly , Accuracy of open sensor and closed sensor 、 The stability is basically the same . in summary , The open-ended Hall current sensor has a wider application in the process of DC distribution transformation .

reference

[1] Enterprise microgrid design and Application Manual .2020.6