Impact studies of distributed generation on power quality and protection setup of an existing distribution network (original) (raw)
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Investigation of the Effects of Distributed Generation on Protection Coordination in a Power System
Engineering, Technology & Applied Science Research
The rapid increase of the electrical power demand gave rise to many challenging situations for power system control engineers as the transmission lines are operating at their maximum capacity in most developing economies. To solve this, Distributed Generation (DG), i.e. the generation of electrical power in a distribution network that provides clean energy, is gaining popularity. There are several challenges the protection of distribution networks faces after DG installation, such as variations in short circuit levels, protection blinding, reverse power flow, protection coordination, change in fault impedance, recloser-fuse coordination, selectivity, unsynchronized reclosing, false tripping, etc. In this paper, an IEEE 13-Bus System Radial Distribution System is simulated using Electrical Transient Analyzer Program (ETAP), various scenarios of DG placement are considered, their impact on the protection system is analyzed, and different techniques are proposed to minimize the effect ...
Investigation of the Impact of Distributed Generation on Power System Protection
Advances in Science, Technology and Engineering Systems Journal
Integration of Distributed Generation (DG) on distribution networks has a positive impact which includes the following: low power losses, improved utility system reliability and voltage improvement at buses. A real distribution network is radial in which energy flow is unidirectional from generation to transmission and from distribution to the load. However, when a DG is connected to it, the power flow becomes bidirectional, and the protection setting of the network may be affected. Therefore, the aim of this research work is to investigate the impact of distributed generation DG on power system protection. The test distribution network is first subjected to load flow analysis to determine its healthiness with and without DG connection. The load flow results confirm that the integration of the DG into the distribution network reduces the active power load loss by 92.68% and improves voltage profiles at each bus of the network by 90.72%. Thereafter, the impact of DG on the protection setting of the existing test network was investigated. Integrating DGs to the network, from our result, shows an increase in the fault currents, which in turn caused false tripping, nuisance tripping, and blinding of protection relay compared with when DGs are not connected. The protection relays were reset at the point of common coupling (PCC) to prevent any abnormal tripping. This is the major contribution of the research work.
Impact of distributed power generation on protection coordination in distribution network
Indonesian Journal of Electrical Engineering and Computer Science
In the whole world and especially in Morocco, the electric power sector faces significant challenges and the demand for energy is increasing as fossil fuel sources are disappearing. Moreover, the high cost of construction of large production plants and the obligation to reduce greenhouse gas emissions are among the factors pushing the energy sector to integrate distributed generators DGs based on renewable energies into power grids. However, the integration of these generators increased the values of short-circuit currents in the network, which poses a real threat to the existing protection coordination systems in the distribution network. The aim of this article is to bring together in a single platform all available research addressing the issue of protection coordination in the presence of DGs in the distribution network, in order to help researchers identify future scope. This paper presents a review of the impact of distributed generators on the protection coordination of distr...
IET Generation, Transmission & Distribution, 2020
Power networks, especially distribution networks, have been undergoing substantial changes since the application of new technologies. Technology development in the early part of the 21st century has opened up new horizons for automated, efficient and reliable power grids. New technologies, while enhancing the capability of the electrical networks and providing opportunities and innovative solutions to the challenges of future networks, can also cause drawbacks that should be investigated and taken into account. Distributed generation (DG) is one of the new technologies that improves the operation of power grids. Despite tangible benefits that integration of DG units brings to electrical grids, their notable impacts on protection systems of power networks raise many challenges and concerns on how a fault should be detected and isolated in active distribution networks. Many attempts have been made to investigate the downside of the interconnection of DG units and methods to mitigate their impacts have been proposed. This study reviews the impact of DG integration on protection systems addressed in other research works and recapitulates suggested methods provided by scholars.
Impact of distributed generation on the protection of distribution networks
… in Power System Protection, …, 2004
Distributed generation (DG) inclusion within the grid system potentially introduces problems related to control, protection, harmonics, and network transients. This paper analyses one of the key issues: protection of the network, by ascertaining the impact of rotary DG inclusion on existing protection system of SWER (single wire earth return) lines and the DG sensitivity during faults. The analysis is carried out by estimating fault-sensitivity for the worst-case situation, determining the DG impact on the existing protection scheme, and comparing the network situation with and without DG during the fault. A model of arc voltage is used to represent a fault on a SWER scheme. The size of DG is selected based on the SWER capacity and SWER load. The study is conducted on an example SWER system by considering the SWER lines with and without DG and faults on the SWER backbone and laterals, and simulation results are reported. In every case studied, the fault current from the DG significantly exceeded the DG rating and the DG would have tripped. Thus the system reverts to the case with no DG. Even if DG did not trip, the fault current from the source would be largely independent of the DG, and thus the original feeder protection would continue to provide the same quality of performance. Hence, net sensitivity and existing protection system will not be adversely affected by DG inclusion in SWER lines. #
Distributed Generation Adverse Impact on the Distribution Networks Protection and Its Mitigation
Heliyon, 2022
Integration of Distributed Generation (DG) generates problems for the protection of Distribution Networks (DNs) in power systems. When DG is integrated into a power distribution system (DS), the radial nature of the network is altered and the power starts to flow in a reverse direction. In addition to the reverse flow of power, the DG upsurges the fault current level and affects the existing time intermission coordination of the protective overcurrent relay. This study proposes a reverse power relay (RPR) and Fault Current Limiter (FCL) to mitigate the fault current level and reverse power flow in a Distribution Network (DN) by the use of DG. The FCL works only as a unidirectional fault current limiter (UFCL) by restricting the flow of fault current that occurs in the main grid (MG) of the DG. However, FCLs can protect the flow of fault currents from the MG by affecting the operational flexibility and reliability of the DG. To overcome the flow of fault current of the DG, this study proposes RPR to monitor the power flow to the DG. Collectively the study focuses on the protection of radial DS by using RPR and UFCL. The analysis and the modeling were conducted on the 15KV DN of the radial feeder in Debre Markos DN. The 3Φ fault analysis (which is more severe than others) was performed to validate the protection capability of the mitigation techniques which were proposed in this study.
Impact of Distributed Generation on Power System Protection
This paper presents the impacts of distributed generation (DG) on power system protection. With the increase in DG penetration to the power system network, it has become necessary to evaluate the potential impacts of DG on the existing protection schemes through detailed simulation and protection studies to ensure reliability and security of the system. A radial feeder model with existing protection system and DG are modeled in PSCAD/EMTDC software. Common protection issues such as false tripping, nuisance tripping, unintentional islanding, neutral shifting, resonance and blinding protection are discussed and simulated. Relay co-ordination characteristics are analyzed before and after addition of DGs. Possible mitigation methods are demonstrated with simulation results and relay coordination curves.
2010
Conventional power distribution system is radial in nature, characterized by a single source feeding a network of downstream feeders. Protection scheme for distribution system, primarily consisting of fuses and reclosures and, in some cases, relays, has traditionally been designed assuming the system to be radial. In last year extra attention applied in use of distributed generator units in distribution networks. The integration of distributed sources into existing networks brings up several technical, economical and regulatory questions. The connection of distributed generators (DG) to distribution networks also influences the performance of the networks and the impact depends on the number, location and size of injected DG. The presence of distributed generators in the distribution network can cause the mis-coordination of the protection system. In order to overcome this problem, one can change the relay setting based on the number and location of DGs in the network. In this paper...
Reviewing the Effect of Distributed Generation Interconnections on Distribution Systems
"Application of distributed generation (DG) to supply the demand of a diverse customer base has been gaining popularity. Various DG technologies are being integrated into power systems to provide alternatives to energy sources or to improve reliability. The paper aims at providing an overview of the impact that distributed generation might have on the operation of distributed network. Issues like impact of DG on losses, voltage control, power quality, short circuit power, reliability,insulation and system protection are discussed.Based on the discussion, it can be concluded that the impact of DG depends on perpetration of DG in the distribution network as well as on the DG technology.Furthermore critical issues, for example theimpact of DG on the protection system, canbe solved by using the right technology"