scholarly journals Tolerance of Electromagnetic Relay to Voltage Sags and Short Interruptions

2021 ◽  
Vol 9 ◽  
Author(s):  
Huaying Zhang ◽  
Qing Wang ◽  
Yihong You
Keyword(s):  
Test List ◽  
Test Procedure ◽  
Economic Assessment ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Mechanism Analysis ◽  
Response Mechanism ◽  
Two Stage ◽  
Electromagnetic Relay ◽  
Magnitude Variation

This paper studies the tolerance of electromagnetic relay (EMR) under voltage sag and short interruptions on the basis of response mechanism analysis and the extensive tests. First, it introduces the structure of EMR and proposes response mechanism of EMR under voltage sag. Then, a detailed test plan is presented, including the information of test platform, testing condition, EMRs used in test, list of test, test procedure, and the measured waveforms. Magnitude and duration of the sags are not only the characteristics to be considered to investigate EMR’s tolerance. The other factors, which may have significance influence on tolerance of EMR, are considered here, including point-on-wave (POW), phase angle jump (PAJ), harmonic, magnitude variation in pre- and post-sag segments, two-stage sag, and slow recovery sag. Extensive tests results are presented in the form of voltage-tolerance curves (VTCs). Besides magnitude and duration, POW, PAJ, and two-stage sag have a significant influence on the tolerance of EMR. Other factors only have a tiny impact on the tolerance of EMR. The results show that the magnitude tolerance of EMR is 48–74% of Unom, and duration tolerance is 5–28 ms; they are useful for the technical assessment of EMR’s tolerance to voltage sags and short interruptions, and for the economic assessment of the industry process trip due to its disengagement. Test results also benefit for choosing proper EMR and mitigation device in the complicated operating environment.

scholarly journals Conversores de freqüencia VSI-PWM submetidos a afundamentos temporários de tensão ("voltage sags")

2003 ◽  
Vol 14 (1) ◽  
pp. 50-57
Author(s):  
Paulo C. A. Leão ◽  
José C. de Oliveira ◽  
Kleiber D. Rodrigues
Keyword(s):  
Voltage Sag ◽  
Voltage Sags

Este artigo tem por objetivo analisar a interdependência entre a operação de conversores de freqüência tipo VSI-PWM e uma das manifestações mais comuns para a perda de qualidade de um suprimento elétrico, qual seja, a ocorrência do fenômeno denominado por afundamento temporário de tensão ou "voltage sag". São apresentados resultados de simulações, realizadas no Simulador Saber, de um sistema típico submetido a afundamentos de tensões simétricos e assimétricos. Resultados de ensaios em laboratório também são fornecidos com vistas à validação dos resultados computacionais. Aspectos relacionados com a capacidade "ride-through" dos conversores e correspondentes arranjos de proteção são também considerados.

Voltage Sag Evaluation Method of a Real Distribution System Based on a Connection Number Model

2013 ◽  
Vol 341-342 ◽  
pp. 1363-1366
Author(s):  
Lang Bai ◽  
Le Yu
Keyword(s):  
Distribution System ◽  
Evaluation Method ◽  
Assessment Model ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Connection Number ◽  
Reliability Parameters ◽  
Real Distribution ◽  
System Components ◽  
Simulation Results

The evaluation results of power system are greatly influenced by the reliability parameters and uncertainty of system components. The connection number assessment model and an approach have been presented to assess the occurrence frequency due to voltage sags. The proposed method had been applied to a real distribution system. Compared with the interval number method, the simulation results have shown that this method is simple and flexible.

Failure Mechanism Analysis of Electromagnetic Relay under Mechanical Impact

2013 ◽  
Vol 473 ◽  
pp. 39-45 ◽  
Author(s):  
Guo Wei Zhao ◽  
Yong Chen ◽  
De Yong Li ◽  
Bin Tang
Keyword(s):  
Failure Mechanism ◽  
Magnetic Circuit ◽  
Impact Damage ◽  
Engineering Application ◽  
Air Gap ◽  
Mechanism Analysis ◽  
Mechanical Impact ◽  
Electromagnetic Relay ◽  
Electromagnetic Relays ◽  
The Impact

The aim was to analyze failure mechanism of electromagnetic relay caused by mechanical impact. The principle of electromagnetic relays was studied and the effect of mechanical impact on electromagnetic relays was analyzed in this paper. Based on the established magnetic circuit model, the relationship of the magnetic field strength, the electromagnetic attraction and the impact damage degree was studied. Then, the damage intensity of mechanical impact on magnetic circuit was decided. Afterwards, the structure of electromagnetic relays was improved, and the mechanical impact simulation was studied by ANSYS. The results show that the uncontrollability of electromagnetic relay is mainly caused by air gap, which is aroused by mechanical impact; in addition, the size of air gap is inversely proportional to electromagnetic attraction force. Moreover, the improved structure of relays can increase impact resistance and broaden the scope of engineering application of electromagnetic relay.

DC-side faults mechanism analysis and causes location for two-stage photovoltaic grid connected inverters

2021 ◽  
pp. 114229
Author(s):  
Mingyao Ma ◽  
Pengbo Xiong ◽  
Nianwen Xiang ◽  
Hanyu Wang ◽  
Xuesong Meng
Keyword(s):  
Mechanism Analysis ◽  
Two Stage

scholarly journals Ride through testing of variable speed drive due to voltage sag types (types I, II and III)

2019 ◽  
Vol 10 (2) ◽  
pp. 690
Author(s):  
Surya Hardi ◽  
R. Harahap ◽  
S. Ahmad ◽  
M. Isa
Keyword(s):  
Drop Out ◽  
Dropping Out ◽  
Voltage Sag ◽  
Type I ◽  
Voltage Sags ◽  
Test Results ◽  
Variable Speed ◽  
Variable Speed Drives ◽  
Standard Curve ◽  
Test Points

Variable speed drives (VSDs) are widely used in various applications mainly in process industry need constant rotational speed. It is developed from power electronic components thus saving energy in its operation. Unfortunately it is susceptible against power quality problem for example voltage sags. The VSD may be disruption or drop out when it is supplied by voltage sags and it is determined by sag characteristics. This study is to investigate effect of voltage sags Types I, II and III on VSD through laboratory testing. The voltage sags characteristics are generated from voltage sag generator (Shaffner 2100 EMC).  The effects are presented in susceptibility curves in disruption and drop out conditions. The curves resulted are evaluated by standard curve recommended. Test results show that voltage sag Type I cause the VSD disruption only, whereas two types sag other result in the VSD disruption and also drop out. Evaluation results explain  a few test points are in operation area for disruption condition whereas test points for dropping out far below the threshold recommended. Hence the VSD has good quality to voltage sags.

scholarly journals Effects of unsymmetrical voltage sags on industrial adjustable speed drives

2009 ◽  
Vol 6 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Milutin Petronijevic ◽  
Nebojsa Mitrovic ◽  
Vojkan Kostic ◽  
Bojan Bankovic
Keyword(s):  
Control Algorithm ◽  
Torque Ripple ◽  
Performance Degradation ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Control Methods ◽  
Adjustable Speed Drives ◽  
Electric Drives ◽  
Adjustable Speed

This paper researches unsymmetrical voltage sag influence on torque ripple in scalar controlled (V/Hz), rotor field oriented (RFO) and direct torque controlled (DTC) drives. Electric drives performance degradation during voltage sag mainly depends on the used control algorithm. Industrial drives with all three types control methods are experimentally tested. Experiments with digital observer's application confirm the proposed solution. .

Proposed Topology for Voltage Sag Mitigation with New Control Strategy

2019 ◽  
Vol 15 (2) ◽  
pp. 138-144
Author(s):  
Adnan Diwan ◽  
Khalid Abdulhasan
Keyword(s):  
Duty Cycle ◽  
Control Strategy ◽  
Output Voltage ◽  
System Analysis ◽  
Control Method ◽  
Boost Converter ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Long Duration ◽  
Simulation Results

voltage sags represent the greatest threat to the sensitive loads of industrial consumers, the microprocessor based-loads, and any electrical sensitive components. In this paper, a special topology is proposed to mitigate deep and long duration sags by using a modified AC to AC boost converter with a new control method. A boost converter is redesigned with a single switch to produces an output voltage that is linearly proportional to the duty cycle of the switch. On the other hand, the proposed control system is based on introducing a mathematical model that relates the missing voltage to the duty cycle of the boost converter switch. The simulation results along with the system analysis are presented to confirm the effectiveness and feasibility of the proposed circuit.

scholarly journals Two-Stage Multi-Objective Meta-Heuristics for Environmental and Cost-Optimal Energy Refurbishment at District Level

2019 ◽  
Vol 11 (5) ◽  
pp. 1495 ◽  
Author(s):  
Diana Manjarres ◽  
Lara Mabe ◽  
Xabat Oregi ◽  
Itziar Landa-Torres
Keyword(s):  
Performance Optimization ◽  
Energy Demand ◽  
Harmony Search ◽  
Economic Assessment ◽  
District Level ◽  
The European Union ◽  
Two Stage ◽  
Nsga Ii ◽  
Multi Objective ◽  
Payback Time

Energy efficiency and environmental performance optimization at the district level are following an upward trend mostly triggered by minimizing the Global Warming Potential (GWP) to 20% by 2020 and 40% by 2030 settled by the European Union (EU) compared with 1990 levels. This paper advances over the state of the art by proposing two novel multi-objective algorithms, named Non-dominated Sorting Genetic Algorithm (NSGA-II) and Multi-Objective Harmony Search (MOHS), aimed at achieving cost-effective energy refurbishment scenarios and allowing at district level the decision-making procedure. This challenge is not trivial since the optimisation process must provide feasible solutions for a simultaneous environmental and economic assessment at district scale taking into consideration highly demanding real-based constraints regarding district and buildings’ specific requirements. Consequently, in this paper, a two-stage optimization methodology is proposed in order to reduce the energy demand and fossil fuel consumption with an affordable investment cost at building level and minimize the total payback time while minimizing the GWP at district level. Aimed at demonstrating the effectiveness of the proposed two-stage multi-objective approaches, this work presents simulation results at two real district case studies in Donostia-San Sebastian (Spain) for which up to a 30% of reduction of GWP at district level is obtained for a Payback Time (PT) of 2–3 years.

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