Adaptive Differential Protection System for Microgrid

Microgrids are the small version of power system which grants us the integration of distributed generation resources to insure the facilities to the remotely located electric loads as well as have so many advantages over traditional power system like reduced transmission loss, green energy solution and proper use of renewable energy resources. However the resilience offered by microgrid is inconvenient if it is not be able to protect properly in case of any disturbance occurs which is very common in microgrid due to load dynamics. Protective devices used in traditional power grid cannot actually protect microgrid due to variable loads and different fault levels at grid connected modes and islanded modes. The available research about this concern has not been very successful, therefore options like distance, directional over current and differential relay remains effective protection scheme from present standard. Even though these relays are very useful in power system but their effectiveness for microgrid is yet to be analyzed. This paper is presenting the MATLAB simulation based analysis for differential relay type adaptive protection system by taking a complex microgrid model and generating various fault and generation capacities and analyzing it. In this paper different scenarios has been discussed where differential relay seems to be better than distance and directional over current relay protection scheme.

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Fault Analysis and Design of a Protection System for a Mesh Power System with a Co-Axial HTS Power Cable

Energies ◽

10.3390/en13010220 ◽

2020 ◽

Vol 13 (1) ◽

pp. 220 ◽

Cited By ~ 1

Author(s):

Thai-Thanh Nguyen ◽

Woon-Gyu Lee ◽

Hak-Man Kim ◽

Hyung Yang

Keyword(s):

Power System ◽

Fault Analysis ◽

Protection System ◽

Power Cable ◽

Analysis And Design ◽

Protection Scheme ◽

System Protection ◽

Protection Systems ◽

Overcurrent Relays ◽

System Characteristics

The uses of high-temperature superconducting (HTS) cables pose a challenge of power system protection since the impedance of the HTS cable is varied during fault conditions. The protection systems should be designed properly to ensure the reliability and stability of the whole system. This paper presents a fault analysis of the co-axial HTS cable in the mesh system and proposes a coordinated protection system. In the proposed protection system, the main protection is the differential current relay whereas the backup protections are the overcurrent and directional overcurrent relays. The normal and abnormal relay operations are considered to analyze the transient fault current in the HTS cable and evaluate the performance of the proposed coordinated protection system. Characteristics of cable impedances and temperatures under various fault conditions are presented. The proposed protection scheme is validated by the simulation in the PSCAD/EMTDC program. Simulation results show that the coordinated protection scheme could successfully protect the HTS cables in both normal and abnormal relay operations.

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The Solution for Malfunction of the Leakage Protection System Caused by Mine-Used Converter

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.912-914.1481 ◽

2014 ◽

Vol 912-914 ◽

pp. 1481-1484

Author(s):

Yan Wen Wang ◽

Hai Hong Li ◽

Da Wei Wang ◽

Zheng Fan

Keyword(s):

Power System ◽

Coal Mine ◽

Protection System ◽

Normal Operation ◽

Coal Production ◽

Actual Situation ◽

Matlab Simulation ◽

Zero Sequence ◽

Working Principle ◽

Isolation Transformer

The leakage protection system usually trends to make a misjudgment and tripping in normal operation after applying the converter in the coal mine power system. This seriously affects the safety in coal production. Based on the research of the structure and working principle of the converter, it has obtained the definite reason for the converter interfere the leakage protection system. It is the higher harmonics and pulses that generate the zero sequence current through the ground capacitance. Combined with the actual situation in coal mine, it has proposed two corresponding solutions: one is adding the isolation transformer in the output lines of the converter; another is modifying criterion of the leakage protection system. Both methods have their own characteristics, and have verified the feasibility of the methods through the MATLAB simulation.

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Demand-Side Contribution to Power System Frequency Regulation : -A Critical Review on Decentralized Strategies

International Journal of Emerging Electric Power Systems ◽

10.1515/ijeeps-2016-0237 ◽

2017 ◽

Vol 18 (3) ◽

Cited By ~ 6

Author(s):

Atieh Delavari ◽

Innocent Kamwa

Keyword(s):

Power System ◽

New England ◽

Critical Review ◽

Control Strategies ◽

Test System ◽

Frequency Regulation ◽

Renewable Energy Resources ◽

Simulation Based ◽

Detailed Simulation ◽

System Frequency

Abstract Nowadays the contribution of smart load technologies to power system frequency regulation is spurred due to the increasing penetration of renewable energy resources. This paper presents a comprehensive and up-to-date critical review on different decentralized load control strategies. This includes a joint literature- as well as simulation-based investigation in order to scrutinize different decentralized frequency-based load modulation strategies through organizing a taxonomy table and performing different simulation scenarios. Furthermore, the effectiveness of different gain tuning procedures in each control action are scrutinized and compared in terms of frequency nadir and steady state error. The detailed simulation is performed using SimPowerSystem (SPS) toolbox, in phasor mode, on IEEE 39-bus New England test system.

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A Wavelet Based Differential Algorithm for Busbar Protection

International Research Journal of Multidisciplinary Technovation ◽

10.34256/irjmt1934 ◽

2019 ◽

Vol 1 (3) ◽

pp. 28-39

Author(s):

Bharath Kumar Sugumar ◽

Sujatha Balaraman

Keyword(s):

Power System ◽

Differential Protection ◽

Network Stability ◽

Protection Scheme ◽

Level 3 ◽

System Node ◽

Internal Faults ◽

Important System ◽

Bus System ◽

External Faults

Busbar protection is an essential component in power system design, protecting the most important system node for network stability and security. When faults occurs on busbar itself, it takes much time to isolate the bus from source which may cause much damage in the bus system. Faults in power system are classified as internal and external faults. Faults within the zone are termed as internal faults whereas, the faults outside the Zone are called as external faults. Ideally, a relay looking after the protection of a zone should operate only for internal faults. It should restrain from operating for external faults or through faults. In this paper the busbar protection using differential protection scheme has been investigated for internal and external faults. An algorithm has been developed to improve the selectivity of the relay and the same has been tested in IEEE9 bus system for internal and external faults. Separation of De-noised signal from fault signal is made using wavelet transform so that the nature of fault occurs on the system can be identified. In this study Daubechies 4 at level 3 is used to separate original signal and de-noised signal. The entire simulation has been done using MATLAB R2017a.

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