A Novel Low-Cost Multicoil-Based Smart Current Sensor for Three-Phase Currents Sensing of Overhead Conductors

2016 ◽  
Vol 31 (6) ◽  
pp. 2443-2452 ◽  
Author(s):  
Junyong Wu ◽  
Zhanfeng Chen ◽  
Chen Wang ◽  
Liangliang Hao
Keyword(s):  
Low Cost ◽  
Author(s):  
Karan S Belsare ◽  
Gajanan D Patil

A low cost and reliable protection scheme has been designed for a three phase induction motor against unbalance voltages, under voltage, over voltage, short circuit and overheating protection. Taking the cost factor into consideration the design has been proposed using microcontroller Atmega32, MOSFETs, relays, small CTs and PTs. However the sensitivity of the protection scheme has been not compromised. The design has been tested online in the laboratory for small motors and the same can be implemented for larger motors by replacing the i-v converters and relays of suitable ratings.


Author(s):  
José Luis Viramontes-Reyna ◽  
Josafat Moreno-Silva ◽  
José Guadalupe Montelongo-Sierra ◽  
Erasmo Velazquez-Leyva

This document presents the results obtained from the application of the law of Lens to correctly identify the polarity of the windings in a three-phase motor with 6 exposed terminals, when the corresponding labeling is not in any situation; Prior to identifying the polarity, it should be considered to have the pairs of the three windings located. For the polarity, it is proposed to feed with a voltage of 12 Vrms to one of the windings, which are identified randomly as W1 and W2, where W1 is connected to the voltage phase of 12 Vrms of the signal and W2 to the voltage reference to 0V; by means of voltage induction and considering the law of Lens, the remaining 4 terminals can be identified and labeled as V1, V2, U1 and U2. For this process a microcontroller and control elements with low cost are used.


Author(s):  
Luo Xiaohui

This paper proposed a low cost wireless monitoring system based on ZigBee wireless transmission, and designed a new floating voltage sensor which is suitable for the monitoring of medium voltage and high voltage(MV/HV) public equipment. The system used TI-CC2530 as the controller, proposed a new moving average voltage sensing(MAVS) algorithm by reasonable assumptions, and adopted algorithms to perform the theoretical analysis for the single phase and three-phase voltage. At last, the author carried out a practical experiment on the wireless floating voltage sensor under the voltage up to 30kV, the experimental results showed that the proposed low cost wireless sensor can achieve a good voltage monitoring function, and the error is less than 3%.


2013 ◽  
Vol 834-836 ◽  
pp. 930-934
Author(s):  
Shou Liang Yang ◽  
Bao Liang Yang

The paper proposes a new design of high-accuracy On-line Metal Thickness Measuring Instrument, which was based on EP2C20 series FPGA chip, through adding NiosII soft processor and other interfaces to FPGA, equipped with high precision data collection system and TFT LCD module and so on. The key hardware blocks schematics and components of the RC Oscillation Circuit,eddy current sensor Circuit,rectifier and filter Circuit,A/D converting circuit,FPGA Circuit are described,software flow charts and sample codes are given. According to practice, The measurement range of this system is 1~100 mm and the resolving power is 0.1 μm. degree of linearity is 1%, The system has many features including small volume of hardware, low cost, high detecting precision, convenient operating, high intelligent and so on, leading to broad and bright future. Key words: NiosII processor; eddy current sensor; metal thickness


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