Investigating the effect of DG infeed on the effective cover of distance protection scheme in mixed-MV distribution network

The environmental and economic features of renewable energy sources have made it possible to be integrated as Distributed Generation (DG) units in distribution networks and to be widely utilized in modern distribution systems. The intermittent nature of renewable energy sources, altering operational conditions, and the complex topology of active distribution networks makes the level of fault currents significantly variable. Thus, the use of distance protection scheme instead of conventional overcurrent schemes offers an appropriate alternative for protection of modern distribution networks. In this study, the effect of integrating multiple DG units on the effective cover of distance protection schemes and the coordination between various relays in the network was studied and investigated in radiology and meshed operational topologies. Also, in cases of islanded and grid-connected modes. An adaptive distance scheme has been proposed for adequate planning of protection schemes to protect complex networks with multiple distribution sources. The simplified simulated network implemented in NEPLAN represents a benchmark IEC microgrid. The comprehensive results show an effective protection measure for secured microgrid operation.Article History: Received October 18th 2017; Received in revised form May 17th 2018; Accepted July 8th 2018; Available onlineHow to Cite This Article: Saad, S.M., Naily, N.E. and Mohamed, F.A. (2018). Investigating the Effect of DG Infeed on the Effective Cover of Distance Protection Scheme in Mixed-MV Distribution Network. International Journal of Renewable Energy Development, 7(3), 223-231.https://doi.org/10.14710/ijred.7.3.223-231

Download Full-text

Effect of Distributed Photovoltaic Generation on Short-Circuit Currents and Fault Detection in Distribution Networks: A Practical Case Study

Applied Sciences ◽

10.3390/app11010405 ◽

2021 ◽

Vol 11 (1) ◽

pp. 405

Author(s):

Daniel Alcala-Gonzalez ◽

Eva Maria García del Toro ◽

María Isabel Más-López ◽

Santiago Pindado

Keyword(s):

Renewable Energy ◽

Radial Distribution ◽

Short Circuit ◽

Renewable Energy Sources ◽

Distribution Network ◽

Distribution Networks ◽

Energy Sources ◽

Protection Devices ◽

Short Circuits ◽

Short Circuit Currents

The increase in the installation of renewable energy sources in electrical systems has changed the power distribution networks, and a new scenario regarding protection devices has arisen. Distributed generation (DG) might produce artificial delays regarding the performance of protection devices when acting as a result of short-circuits. In this study, the preliminary research results carried out to analyze the effect of renewable energy sources (photovoltaic, wind generation, etc.) on the protection devices of a power grid are described. In order to study this problem in a well-defined scenario, a quite simple distribution network (similar to the ones present in rural areas) was selected. The distribution network was divided into three protection zones so that each of them had DG. In the Institute of Electrical and Electronic Engineers (IEEE) system 13 bus test feeder, the short-circuits with different levels of penetration were performed from 1 MVA to 3 MVA (that represent 25%, 50%, and 75% of the total load in the network). In the simulations carried out, it was observed that the installation of DG in this distribution network produced significant changes in the short-circuit currents, and the inadequate performance of the protection devices and the delay in their operating times (with differences of up to 180% in relation to the case without DG). The latter, that is, the impacts of photovoltaic DG on the reactions of protection devices in a radial distribution network, is the most relevant outcome of this work. These are the first results obtained from a research collaboration framework established by staff from ETSI Civil and the IDR/UPM Institute, to analyze the effect of renewable energy sources (as DG) on the protection devices of a radial distribution network.

Download Full-text

Influence of FACTS Device Implementation on Performance of Distribution Network with Integrated Renewable Energy Sources

Energies ◽

10.3390/en13205516 ◽

2020 ◽

Vol 13 (20) ◽

pp. 5516

Author(s):

Filip Relić ◽

Predrag Marić ◽

Hrvoje Glavaš ◽

Ivica Petrović

Keyword(s):

Renewable Energy ◽

Distribution System ◽

Low Voltage ◽

Flow Direction ◽

Renewable Energy Sources ◽

Distribution Network ◽

Distribution Networks ◽

Energy Sources ◽

Voltage Profile ◽

Facts Devices

In the modern power system, Flexible Alternating Current Transmission System (FACTS) devices are widely used. An increased share of the distributed generation (DG) and the development of microgrids change the power flows in the existing distribution networks as well as a conventional power flow direction from the transmission to the distribution network level which may affect the overall stability aspects. The paper shows the FACTS devices’ implementation influence on the performance of the distribution network with integrated renewable energy sources (RES) observing the aspects of the oscillatory stability and the low-voltage motor starting. The FACTS devices, in particular the static var compensators (SVC), have been allocated according to a novel algorithm proposed in the paper. The algorithm uses an iterative process to determine an optimal location for implementation and rating power of SVC considering active power losses minimization, improvement of the voltage profile and maximizing return of investment (ROI) of FACTS devices. Novel constraints—transformer station construction constraint, SVC industrial nominal power value constraint and the constraint of distribution system operator (DSO) economic willingness to investment in the distribution network development are considered in the proposed algorithm. The analysis has been performed on 20 kV rural distribution network model in DIgSILENT PowerFactory software.

Download Full-text

The Power System and Microgrid Protection—A Review

Applied Sciences ◽

10.3390/app10228271 ◽

2020 ◽

Vol 10 (22) ◽

pp. 8271 ◽

Cited By ~ 1

Author(s):

Jalal Sahebkar Farkhani ◽

Mohammad Zareein ◽

Arsalan Najafi ◽

Rui Melicio ◽

Eduardo M. G. Rodrigues

Keyword(s):

Renewable Energy ◽

Power Systems ◽

Renewable Energy Sources ◽

Distribution Network ◽

Protection System ◽

Local Network ◽

Energy Sources ◽

Generation Model ◽

Protection Scheme ◽

Protection Systems

In recent years, power grid infrastructures have been changing from a centralized power generation model to a paradigm where the generation capability is spread over an increasing number of small power stations relying on renewable energy sources. A microgrid is a local network including renewable and non-renewable energy sources as well as distributed loads. Microgrids can be operated in both grid-connected and islanded modes to fill the gap between the significant increase in demand and storage of electricity and transmission issues. Power electronics play an important role in microgrids due to the penetration of renewable energy sources. While microgrids have many benefits for power systems, they cause many challenges, especially in protection systems. This paper presents a comprehensive review of protection systems with the penetration of microgrids in the distribution network. The expansion of a microgrid affects the coordination and protection by a change in the current direction in the distribution network. Various solutions have been suggested in the literature to resolve the microgrid protection issues. The conventional coordination of the protection system is based on the time delays between relays as the primary and backup protection. The system protection scheme has to be changed in the presence of a microgrid, so several protection schemes have been proposed to improve the protection system. Microgrids are classified into different types based on the DC/AC system, communication infrastructure, rotating synchronous machine or inverter-based distributed generation (DG), etc. Finally, we discuss the trend of future protection schemes and compare the conventional power systems.

Download Full-text

Application of PSO for optimal coordination of directional over-current relays in distribution system with distributed renewable energy sources

International Journal of Advances in Applied Sciences ◽

10.11591/ijaas.v10.i2.pp188-192 ◽

2021 ◽

Vol 10 (2) ◽

pp. 188

Author(s):

Lazhar Bougouffa ◽

Abdelaziz Chaghi

Keyword(s):

Renewable Energy ◽

Power Distribution ◽

Distribution System ◽

Distribution Systems ◽

Renewable Energy Sources ◽

Electrical Power ◽

Distribution Networks ◽

Electrical Network ◽

Energy Sources ◽

Optimal Coordination

<p>The use of Distributed Renewable Energy Sources in the electrical network has expanded greatly. But, integration of these resources into distribution systems caused more problems in protection related issues such as mis-coordination, and changes the direction and value of fault currents. When connecting new D-RES to electrical power distribution networks, it is required to re-coordinate Directional Over-CurrentRelays (DOC-Relays) to ensure the continuity of the power transmission when the short circuits take place. This work presented a Particle Swarm Optimization (PSO) algorithm to determine two independent variables called Pickup current (Ip) and Time Dial Setting (TDS) for optimal setting of relays. From analysis result, the impacts of RES location in the distribution system on DOCRs had been observed on the optimal relays settings</p>

Download Full-text

An Effective Bi-Stage Method for Renewable Energy Sources Integration into Unbalanced Distribution Systems Considering Uncertainty

Processes ◽

10.3390/pr9030471 ◽

2021 ◽

Vol 9 (3) ◽

pp. 471

Author(s):

Eman S. Ali ◽

Ragab A. El-Sehiemy ◽

Adel A. Abou El-Ela ◽

Karar Mahmoud ◽

Matti Lehtonen ◽

...

Keyword(s):

Renewable Energy ◽

Radial Distribution ◽

Distribution System ◽

Distribution Systems ◽

Optimization Problems ◽

Renewable Energy Sources ◽

Distribution Networks ◽

Test System ◽

Energy Sources ◽

The Impact

The output generations of renewable energy sources (RES) depend basically on climatic conditions, which are the main reason for their uncertain nature. As a result, the performance and security of distribution systems can be significantly worsened with high RES penetration. To address these issues, an analytical study was carried out by considering different penetration strategies for RES in the radial distribution system. Moreover, a bi-stage procedure was proposed for optimal planning of RES penetration. The first stage was concerned with calculating the optimal RES locations and sites. This stage aimed to minimize the voltage variations in the distribution system. In turn, the second stage was concerned with obtaining the optimal setting of the voltage control devices to improve the voltage profile. The multi-objective cat swarm optimization (MO-CSO) algorithm was proposed to solve the bi-stages optimization problems for enhancing the distribution system performance. Furthermore, the impact of the RES penetration level and their uncertainty on a distribution system voltage were studied. The proposed method was tested on the IEEE 34-bus unbalanced distribution test system, which was analyzed using backward/forward sweep power flow for unbalanced radial distribution systems. The proposed method provided satisfactory results for increasing the penetration level of RES in unbalanced distribution networks.

Download Full-text