scholarly journals AC Microgrid Protection System Design Challenges—A Practical Experience

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 2016
Author(s):  
Sarat Chandra Vegunta ◽  
Michael J. Higginson ◽  
Yashar E. Kenarangui ◽  
George Tsai Li ◽  
David W. Zabel ◽  
...  
Keyword(s):  
System Design ◽  
Distribution Systems ◽  
Failure Modes ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Practical Experience ◽  
Protection System ◽  
Implementation Challenges ◽  
Design Speed ◽  
Design Challenges

Alternating current (AC) microgrids are the next step in the evolution of the electricity distribution systems. They can operate in a grid-tied or island mode. Depending on the services they are designed to offer, their grid-tied or island modes could have several sub-operational states and or topological configurations. Short-circuit current levels and protection requirements between different microgrid modes and configurations can vary significantly. Designing a microgrid’s protection system, therefore, requires a thorough understanding of all microgrid operational modes, configurations, transitional states, and how transitions between those modes are managed. As part of the microgrid protection design, speed and reliability of information flow between the microprocessor-based relays and the microgrid controller, including during microgrid failure modes, must be considered. Furthermore, utility protection practices and customer requirements are not always inclusive of the protection schemes that are unique to microgrids. These and other aspects contribute to the overall complexity and challenge of designing effective microgrid protection systems. Following a review of microgrid protection system design challenges, this paper discusses a few real-world experiences, based on the authors’ own engineering, design, and field experience, in using several approaches to address microgrid protection system design, engineering, and implementation challenges.

scholarly journals Microgrid Protection through Adaptive Overcurrent Relay Coordination

Electricity ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 524-553
Author(s):  
Haneen Bawayan ◽  
Mohamed Younis
Keyword(s):  
Power Flow ◽  
Short Circuit ◽  
Operating Time ◽  
Specific Area ◽  
Short Circuit Current ◽  
Protection System ◽  
Second Phase ◽  
Nonlinear Program ◽  
Overcurrent Relays ◽  
Overcurrent Relay

The inclusion of distributed energy resources (DER) in Microgrids (MGs) comes at the expense of increased changes in current direction and magnitude. In the autonomous mode of MG operation, the penetration of synchronous distributed generators (DGs) induces lower short circuit current than when the MG operates in the grid-connected mode. Such behavior impacts the overcurrent relays and makes the protection coordination difficult. This paper introduces a novel adaptive protection system that includes two phases to handle the influence of fault current variations and enable the MG to sustain its operation. The first phase optimizes the power flow by minimizing the generators’ active power loss while considering tolerable disturbances. For intolerable cases, the second phase opts to contain the effect of disturbance within a specific area, whose boundary is determined through correlation between primary/backup relay pairs. A directional overcurrent relay (DOCR) coordination optimization is formulated as a nonlinear program for minimizing the operating time of the relays within the contained area. Validation is carried out through the simulation of the IEEE 9, IEEE 14, and IEEE 15 bus systems as an autonomous MG. The simulation results demonstrate the effectiveness of our proposed protection system and its superiority to a competing approach in the literature.

scholarly journals Active Reduction of Short-Circuit Current in Power Distribution Systems

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 334
Author(s):  
Esteban Pulido ◽  
Luis Morán ◽  
Felipe Villarroel ◽  
José Silva
Keyword(s):  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Power Converter ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
In Series

In this paper, a new concept of short-circuit current (SCC) reduction for power distribution systems is presented and analyzed. Conventional fault current limiters (FCLs) are connected in series with a circuit breaker (CB) that is required to limit the short-circuit current. Instead, the proposed scheme consisted of the parallel connection of a current-controlled power converter to the same bus intended to reduce the amplitude of the short-circuit current. This power converter was controlled to absorb a percentage of the short-circuit current from the bus to reduce the amplitude of the short-circuit current. The proposed active short-circuit current reduction scheme was implemented with a cascaded H-bridge power converter and tested by simulation in a 13.2 kV industrial power distribution system for three-phase faults, showing the effectiveness of the short-circuit current attenuation in reducing the maximum current requirement in all circuit breakers connected to the same bus. The paper also presents the design characteristics of the power converter and its associated control scheme.

Protection System Monitoring in Electric Networks with Embedded Generation Using Petri Nets

2008 ◽  
Vol 9 (6) ◽  
Author(s):  
Vito Calderaro ◽  
Vincenzo Galdi ◽  
Antonio Piccolo ◽  
Pierluigi Siano
Keyword(s):  
Petri Nets ◽  
Distribution Systems ◽  
Short Circuit ◽  
Distribution Network ◽  
Distribution Networks ◽  
Protection System ◽  
Electric Networks ◽  
Embedded Generation ◽  
Network Operation ◽  
Monitoring Architecture

The connection of distributed generation (DG) essentially changes the distribution network operation and creates a range of well-documented effects varying the voltage levels and short circuit currents. Among others, DG can alter protection system operations in distribution networks, leading to the failure of reclosing, the disconnection of the healthy feeder or the prevention of a protection operation. This paper proposes a procedure, based on Petri nets and supported by a centralized monitoring architecture, for monitoring failures of the protection systems in radial distribution networks. Some case studies applied to a real Italian distribution network proved the effectiveness of the proposed procedure that can therefore represent an effective solution to improve distribution systems reliability in the presence of DG.

Short-Circuit Robustness Testing of SiC MOSFETs

2017 ◽  
Vol 897 ◽  
pp. 525-528 ◽  
Author(s):  
Ronald Green ◽  
Damian P. Urciuoli ◽  
Aivars J. Lelis
Keyword(s):  
Failure Modes ◽  
Gate Dielectric ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Time Duration ◽  
Mode Of Failure ◽  
Chip Size ◽  
Group A ◽  
Source Voltage ◽  
Silicon Based

This paper presents electrical results for two different commercial devices and one prototype 1.2 kV SiC power MOSFET device subject to short-circuit (SC) stress. Two failure modes were observed among the devices tested, with one mode of failure resulting in catastrophic device destruction and the other resulting in permanent damage of the insulating gate dielectric manifested as a leakage current of 400 mA. Short-circuit pulses of increasing time duration caused a reduction in the gate-to-source voltage toward the falling edge of the pulse. This phenomenon is a precursor to failure of SiC MOSFETs under SC stress, but this reduction in VGS is not known to occur in silicon-based devices. The measured short-circuit withstand times for commercial devices from group A and B MOSFETs were 8 us and 12 us, respectively. MOSFET-C devices had a withstand time of 7 us. A larger chip size improves robustness even for large values of peak short-circuit current.

scholarly journals A Novel Machine Learning-Based Short-Circuit Current Prediction Method for Active Distribution Networks

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3793 ◽  
Author(s):  
Zheng ◽  
Wang ◽  
Jiang ◽  
He
Keyword(s):  
Distribution Systems ◽  
Large Scale ◽  
Short Circuit ◽  
Distribution Network ◽  
Prediction Method ◽  
Short Circuit Current ◽  
Distribution Networks ◽  
Test System ◽  
High Penetration ◽  
Active Distribution Networks

The traditional mechanism models used in short-circuit current calculations have shortcomings in terms of accuracy and speed for distribution systems with inverter-interfaced distributed generators (IIDGs). Faced with this issue, this paper proposes a novel data-driven short-circuit current prediction method for active distribution systems. This method can be used to accurately predict the short-circuit current flowing through a specified measurement point when a fault occurs at any position in the distribution network. By analyzing the features related to the short-circuit current in active distribution networks, feature combination is introduced to reflect the short-circuit current. Specifically, the short-circuit current where IIDGs are not connected into the system is treated as the key feature. The accuracy and efficiency of the proposed method are verified using the IEEE 34-node test system. The requirement of the sample sizes for distribution systems of different scale is further analyzed by using the additional IEEE 13-node and 69-node test systems. The applicability of the proposed method in large-scale distribution network with high penetration of IIDGs is verified as well.

Sign in / Sign up

Export Citation Format

Share Document