A low-cost sensor for online detection of a transient abrupt drop in the drive speed of a three-phase synchronous generator

Author(s):  
Mohamed Salah ◽  
Khmais Bacha ◽  
Abdelkader Chaari
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.


2020 ◽  
pp. 0309524X2098177
Author(s):  
Mohamed Metwally Mahmoud ◽  
Hossam S Salama ◽  
Mohamed M Aly ◽  
Abdel-Moamen M Abdel-Rahim

Fault ride-through (FRT) capability enhancement for the growth of renewable energy generators has become a crucial issue for their incorporation into the electricity grid to provide secure, reliable, and efficient electricity. This paper presents a new FRT capability scheme for a permanent magnet synchronous generator (PMSG)-based wind energy generation system using a hybrid solution. The hybrid solution is a combination of a braking chopper (BC) and a fuzzy logic controller (FLC). All proportional-integral (PI) controllers which control the generator and grid side converters are replaced with FLC. Moreover, a BC system is connected to the dc link to improve the dynamic response of the PMSG during fault conditions. The PMSG was evaluated on a three-phase fault that occurs on an electrical network in three scenarios. In the first two scenarios, a BC is used with a PI controller and FLC respectively. While the third scenario uses only FLC without a BC. The obtained results showed that the suggested solution can not only enhance the FRT capability of the PMSG but also can diminish the occurrence of hardware systems and reduce their impact on the PMSG system. The simulation tests are performed using MATLAB/SIMULINK software.


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%.


Sign in / Sign up

Export Citation Format

Share Document