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 Design of Electrical Setting Protection System Indarung VI Cement Plant (Case Study New Cement Plant Construction at PT Semen Padang)

2021 ◽  
Vol 11 (1) ◽  
pp. 43-49
Author(s):  
DIAN EKA PRASETYAWAN
Keyword(s):  
Power Flow ◽  
Short Circuit ◽  
Rapid Development ◽  
Circuit Breaker ◽  
Short Circuit Current ◽  
Electrical Energy ◽  
Protection System ◽  
Cement Plant ◽  
Plant Uses ◽  
Overcurrent Relay

Along with the rapid development of technology and the development of civilization, electrical energy is very important in all fields. This research will conduct a study on the electrical protection system design of PT Semen Padang's Indarung VI Cement Plant using the ETAP 12.6 software. PT Semen Padang's Indarung VI Cement Plant uses three transformers of 150 / 6.3 kV of 30/35 MVA (ONAN / ONAF) and each Main Substation has substations that will supply all the loads to be used. The power flow study shows that the addition of a capacitor bank and a tap changer setting will improve the power factor and voltage of the system, thereby reducing the power supply sent by PLN. The short circuit study shows that the largest short circuit current, which is 35 kA, can be protected by a circuit breaker with a breaking capacity of 40 kA. The protection system coordination study shows that the results of the overcurrent relay setting can protect the electrical system of Indarung VI Cement Plant selectively and safely.

scholarly journals Analisis Kinerja Relai Arus Lebih pada PLTU Embalut PT. Cahaya Fajar Kaltim Unit 1×60 MW dengan Simulasi

2020 ◽  
Vol 17 (2) ◽  
pp. 123
Author(s):  
Agung Prasetyo ◽  
Rusda Rusda ◽  
Masing Masing
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Short Circuit ◽  
Characteristic Curve ◽  
Short Circuit Current ◽  
Electrical Equipment ◽  
Protection System ◽  
East Kalimantan ◽  
Overcurrent Relays ◽  
Overcurrent Relay

Embalut power plant is one of the power plants that supply electricity in East Kalimantan. The plant which is operated by PT. Cahaya Fajar Kaltim, has one PLTU unit with a capacity of 2x25 MW and another with the capacity of 1x60 MW. As an electricity company that must keep continuity of electric supply to customers, a reliable electrical system is necessary. Such reliable system requires protection system to detect a problem and avoid electrical equipment damage. A proper protection system should isolate the affected area and prevent black out on the other area. A type of problem may occur is a short circuit. This study analyzes the performance of overcurrent relays in 1 × 60 MW power plant unit. The analysis was performed through ETAP 12.6.0 software which was also used to design the single line diagrams, calculate the setting currents of short circuit current, also to simulate the coordination of several overcurrent relays in the system. Adjustment of the current and time value in the overcurrent relay is obtained from the result of manual calculations. The results then are displayed in the form of a characteristic curve. Afterwards, a simulation is performed in a situation where three-phase short circuit occurs at BFWP 1.3 Bus, TR AUX.3 Bus and TR 3A.3 Bus. The results show that the overcurrent relays work properly and could overcome the problem quickly.

Joint Regulation of Power Flow and Short Circuit Current Limitations with the Aid of a Phase-Shifting Transformer

2018 ◽  
Vol 51 (5) ◽  
pp. 584-592 ◽  
Author(s):  
A. S. Brilinskii ◽  
G. A. Evdokunin ◽  
R. I. Mingazov ◽  
N. N. Petrov ◽  
V. S. Chudnyi
Keyword(s):  
Power Flow ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Phase Shifting

scholarly journals Implementation of Optimal Protection Coordination for Microgrids with Distributed Generations Using Quaternary Protection Scheme

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Panida Thararak ◽  
Peerapol Jirapong
Keyword(s):  
Short Circuit ◽  
Short Circuit Current ◽  
Test System ◽  
Distributed Generations ◽  
Protection Scheme ◽  
Protection Systems ◽  
Overcurrent Relays ◽  
Operation Test ◽  
Multiple Relay ◽  
Flexible Operation

The flexible operation of microgrids, along with the availability of distributed generation (DG) units, causes a variety of changes in short-circuit current levels, magnitudes, and directions, which has undesirable effects on the operation of protection systems. Conventional protection schemes use typical directional overcurrent relays (DOCRs) with limited operating capability, unable to respond to microgrid operations in the manner of short-circuit current changes. In this paper, a quaternary protection scheme implemented with dual-directional overcurrent relays (dual-DOCR) and a protection control strategy is developed for protecting against faults in microgrids, taking into account the existence of DGs and connection and disconnection of DG units. The optimal dual-DOCRs setting and coordination are formulated as an optimization problem solved by evolutionary programming to minimize the relay operating times. The proposed protection scheme is implemented with a centralized protection control system based on the smart grid concept to increase the adaptability of the dual-DOCRs, which have multiple relay setting groups in accordance with system state changes. The simulation case studies are performed using the IEEE 14-bus test system, which is modified as a meshed microgrid operation. Test scenarios, including possible operations of microgrids, DGs availabilities, and different fault events, are analyzed and discussed. The comparative studies and simulation results show that the proposed scheme provides efficient coordination between the primary and backup relays and increases the responsibility of the protection system, which can be observed from the significant reduction in the relay operating times, resulting in the enhancement of selectivity, sensitivity, and speed of microgrid protection systems.

Fault Current Limitation (FCL) and Voltage Dip Improvement Thanks to Distributed Static Series Compensator (DSSC)

2012 ◽  
Vol 260-261 ◽  
pp. 525-531 ◽  
Author(s):  
Salman Badkubi
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Fault Current ◽  
Additional Function ◽  
Power Flow Control ◽  
Current Limitation ◽  
Fault Currents ◽  
Voltage Dip

This paper presents the comprehensive implementation of Distributed Static Series Compensator (DSSC) to limit the fault currents in power systems. This is the first time that the limitation of fault currents with D-FACTS devices is addressed. DSSC is one of the D-FACTS families whichoperate in a similar manner as Static Synchronous Series Compensator (SSSC) but in smaller size, lower price and more capability. The effectiveness of the DSSC in fault current limitation is investigated through the series voltage effect upon the line. The short circuit current limitation strategy presented here exhibited that besides of the power flow control which is carried out by DSSC; it can also perform this additional function. In the following the potency of the DSSC in reduction of instantaneous voltage dip range during fault current limiting mode is clarified. Furthermore, it is disclosed that with performing more DSSC in the power system, the entire system voltage dip will be improved. In order to validate the claims, computer simulations using PSCAD/EMTDC are exploited.

The Impact of Synchronous Distributed Generation (DG) on Distribution System

2015 ◽  
Vol 785 ◽  
pp. 388-392 ◽  
Author(s):  
Hasmaini Mohamad ◽  
Shahrani Shahbudin ◽  
Nofri Yenita Dahlan
Keyword(s):  
Distributed Generation ◽  
Distribution System ◽  
System Performance ◽  
Power Flow ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Voltage Profile ◽  
Before And After ◽  
Potential Benefits ◽  
The Impact

Interconnection of Distributed Generation (DG) in distribution system presents many potential benefits as well as drawbacks. The impacts of DG might vary with the types of generator. This paper presents a study on the impacts of synchronous DG's interconnection in distribution system. Steady state analysis is carried out to analyze the impact of DG on voltage profile and short circuit current considering before and after DG interconnection. Dynamic analysis is also performed for investigating the performance of DG when a part of distribution system is being islanded. Results show that the penetration of DG contributes to the changes of power flow in the system, hence give impacts to the overall system performance.

Comparative Analysis of the Calculation Results of Online Short-Circuit Current Based on PSASP and Fault Wave Recording

2014 ◽  
Vol 1070-1072 ◽  
pp. 897-901
Author(s):  
Guang Ming Lu ◽  
Wei Zhang ◽  
Jian Feng Yan ◽  
Yong Jun Yu ◽  
Zhi Hong Yu ◽  
...  
Keyword(s):  
Power Flow ◽  
Low Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Online Data ◽  
Operation Process ◽  
Depth Analysis ◽  
Forward Calculation ◽  
Current Calculation ◽  
Wave Recording

In daily operation process,the results of online short-circuit current calculation and fault wave recording is different, the differences between the two results affected the dispatcher’s decision. In-depth analysis of the calculation process and finding the possible causes of the differences should be done. The on-line PSASP short-circuit current calculation based on power flow and scheme was studied. The boundary conditions and calculation models of two methods were studied, the influence of the modeling scope and equivalent circuits to the short-circuit current was also studied. Fault wave recording calculated short-circuit current through forward calculation, the middle to both sides calculation and backward calculation, and the differences of the three calculation mode were also analyzed. Through the above analysis and comparison, online data equivalent to 220kV high voltage side of the transformer greatly impacts short-circuit current, but effective value calculation method of fault wave recording has a little impact on the short-circuit current, mainly in the following reasons, the first one is that non-dispatching power plant is equivalent to a load, the second one is that several different types of load is equivalent to a load using one load model, the third one is that all devices connecting to low voltage side of the 220kV transformers are equivalent to 220kV. Conclusions of the analysis can provide the basis for the practical work of online short-circuit current calculation.

scholarly journals Analysis of Relay Protection System Comparison for Better Identification of Faults in High Voltage AC Transmission Lines

2021 ◽  
Author(s):  
Rimsha Fazal ◽  
Arooj Aslam ◽  
Habib Ullah Manzoor ◽  
Tareq Manzoor
Keyword(s):  
Transmission Line ◽  
High Voltage ◽  
Transmission Lines ◽  
Circuit Breaker ◽  
Operating Time ◽  
Protection System ◽  
Ground Fault ◽  
Double Phase ◽  
Overcurrent Relay ◽  
Ac Transmission

Abstract A high voltage protection system is designed to protect the system against the hazards like instant high voltage condition like lightening voltage in the rain, power variation in the transmission lines etc. In these conditions, our system may face a voltage twice and thrice greater than its original nominal ratings. In this paper, performance of four different relays (overcurrent relay, over and under voltage relay, distance relay and differential relay) have been calculated based on operating time in 400KV high voltage AC transmission line of 80-250km under different faults, modeled on MATLAB for the identification of different types of faults in a transmission line. These relays can differentiate between the normal operating condition and fault conditions. In this paper simulation comparison of these four relays is presented by comparing their operating time in Single line to ground fault (LG), three phase fault (LLLG) and Double phase to ground fault (LLG). The output waveforms are observed under the normal condition or no-fault condition and in the fault condition and response time is calculated to operate a circuit breaker.

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