An Investigation of Relay Protections Trips in Medium Voltage Power Grids

2020 ◽  
Author(s):  
Plamen Stanchev ◽  
Mediha Mehmed-Hamza
Keyword(s):  
Power Grids ◽  
Medium Voltage

scholarly journals Investigation of the Effects of the Arc Fault Resistance and Transient Resistance on the Overcurrent Ground Relay Protection Setting in Medium Voltage Electrical Power Lines

2020 ◽  
Vol 4 (1) ◽  
pp. 67-72
Author(s):  
Plamen Antonov Stanchev ◽  
Mediha Enver Mehmed-Hamza
Keyword(s):  
Power Transformer ◽  
Electrical Power ◽  
Relay Protection ◽  
Power Grids ◽  
Power Lines ◽  
Medium Voltage ◽  
Fault Resistance ◽  
Ground Fault ◽  
Determining Factors ◽  
Transient Voltages

In the medium voltage electrical power lines, the most common fault is the phase to ground fault. The determining factors for selection of the neutral grounding mode of the medium voltage electrical power lines are the selectivity of the relay protection, the transient voltages during phase to ground fault, the magnitude of the fault currents, etc. The paper studies the influence of the transient resistance of phase to ground fault on the selectivity and sensitivity of the earth fault protection when the neutral of the power transformer is grounded through active resistance in medium voltage power grids.

scholarly journals A Lightweight Scheme to Authenticate and Secure the Communication in Smart Grids

2018 ◽  
Vol 8 (9) ◽  
pp. 1508 ◽  
Author(s):  
Israa Aziz ◽  
Hai Jin ◽  
Ihsan Abdulqadder ◽  
Zaid Hussien ◽  
Zaid Abduljabbar ◽  
...  
Keyword(s):  
Smart Grids ◽  
Electrical Power ◽  
Distribution Networks ◽  
Power Grids ◽  
Control Center ◽  
Medium Voltage ◽  
Authentication Mechanism ◽  
Computational Overhead ◽  
Automation Equipment ◽  
Lightweight Authentication

Self-reconfiguration in electrical power grids is a significant tool for their planning and operation during both normal and abnormal conditions. The increasing in employment of Intelligent Electronic Devices (IEDs), as well as the rapid growth of the new communication technologies have increased the application of Feeder Automation (FA) in Distribution Networks (DNs). In a Smart Grid (SG), automation equipment, such as a Smart Breaker (SB), is used. Using either a wired or a wireless network or even a combination of both, communication between the Control Center (CC) and SBs can be made. Nowadays, wireless technology is widely used in the communication of DNs. This may cause several security vulnerabilities in the power system, such as remote attacks, with the goal of cutting off the electrical power provided to significant consumers. Therefore, to preserve the cybersecurity of the system, there is a need for a secure scheme. The available literature investments proposed a heavyweight level in security schemes, while the overhead was not considered. To overcome this drawback, this paper presents an efficient lightweight authentication mechanism with the necessary steps to ensure real-time automatic reconfiguration during a fault. As a first stage, authentication will be made between CC and SB, SB then sends the information about its status. To ensure the integrity of the authentication exchange, a hash function is used, while the symmetric algorithm is used to ensure privacy. The applicability of the suggested scheme has been proved by conducting security performance and analysis. The proposed scheme will be injected on ABB medium voltage breaker with the REF 542plus controller. Therefore, the probable benefit of the suggested scheme is the contribution to provide more flexibility for electrical utilities in terms of reducing the overall computational overhead and withstanding to various types of attacks, while also opening new prospects in FA of SGs.

scholarly journals A dynamical multi-input/multi-output network formulation for stability analysis in AC microgrids

2019 ◽  
Author(s):  
Chrysovalantis Spanias ◽  
Petros Aristidou ◽  
Michalis Michaelides
Keyword(s):  
Stability Analysis ◽  
Power System ◽  
Test System ◽  
Power Grids ◽  
Rotational Inertia ◽  
Numerical Application ◽  
Medium Voltage ◽  
Output System ◽  
The Stability ◽  
And Control

Nowadays, we have witnessed a significant increaseof renewable sources across the existing power grids, as aresult of the undeniable need to mitigate the effects of environmental pollution and assist the economic development of countries around the globe. However, due to the lack of rotational inertia and their intermittent nature, renewables have also increased the severity of the occurring disturbances and instability phenomena, which in turn place a demand for more accurate modeling of the network and the power system components. In this paper, we propose a novel network formulation for AC microgrids that allows the consideration of less conservative conditions for the network, while allowing the adoption of higher order inverter-based generation dynamicsand facilitating the stability analysis and control. In particular, we formulate the network as a dynamical multi-input/multi-output system, which we show is both stable and passive, even if the network’s dynamic and lossy nature is taken into account. We then briefly discuss the opportunities and the advantages offered by the proposed approach and provide useful guidelines for a more accurate modeling of power system components.Finally, we verify the proposed network formulation through a numerical application on the Four Machine Two Area Kundur test system and several simulations on typical Medium Voltage (MV) distribution lines.

scholarly journals The effects of LED light sources on the parameters defining the quality of electricity

2018 ◽  
Vol 19 ◽  
pp. 01006
Author(s):  
Andrzej Lange ◽  
Marian Pasko
Keyword(s):  
High Voltage ◽  
Power Factor ◽  
Low Voltage ◽  
Power Grid ◽  
Power Grids ◽  
Light Sources ◽  
Medium Voltage ◽  
Led Lights ◽  
Voltage Harmonics

The article presents the regulations and standards relating to the quality of electricity, with special emphasis on higher current and voltage harmonics in high-voltage, medium-voltage and low-voltage power grids and the power factor (PF). The parameters defining the quality of electricity consumed by modern LED bulbs for lighting homes, industrial premises such as offices and production halls, as well as roads and yards were measured and analyzed. The current waveforms for LED lights were presented upon connection to the power grid.

scholarly journals Risk assessment of a solar attack according to ISO 31000 standard

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Igor Lavrnić ◽  
Ana Bašić ◽  
Dejan Viduka
Keyword(s):  
Small Businesses ◽  
Power Plants ◽  
Electrical Power ◽  
Electric Energy ◽  
Power Grids ◽  
Power Outage ◽  
Medium Voltage ◽  
Iso 31000 ◽  
Solar Storms ◽  
Eastern European Countries

Energy supply remains the greatest challenge for many of Eastern European countries and their economy. In post-soviet and ex-Yugoslavian countries, till today there exists a system where some of the power plants rely on high voltage (HV) and medium voltage (MV) power grids in the process of distribution of electric energy (EE) to final consumers. This makes them vulnerable to solar storms due to HV power transformers which are especially sensitive to geomagnetic induced current (GIC). The acquisition of electrical power infrastructure could put the electrical infrastructure out of service from a couple of months to a year or more. Loss of income, for ordinary families, is a primary hazard of a long power outage. Business continuity of industry and other critical infrastructures (CI) is important in this scenario, but it is a significant challenge for small businesses and enterprises as well. This paper introduces ISO 31000 standard to such scenarios with the primary goal of achieving resilience of companies against such disaster as a new method of vial response to avoid scope of similar hazards.

scholarly journals Development of a device for control of electric energy parameters in the distribution network

2021 ◽  
Vol 7 (3) ◽  
pp. 106-119
Author(s):  
Ivan M. Kazymov ◽  
Boris S. Kompaneets ◽  
Oleg N. Drobyazko
Keyword(s):  
Electric Energy ◽  
Electrical Energy ◽  
Power Grids ◽  
Electrical Networks ◽  
Power Sector ◽  
Actual Problem ◽  
Medium Voltage ◽  
Industrial Enterprises ◽  
Universal Device ◽  
Transmission Of Information

Background: As of today, the actual problem in the power sector is to create a device for the collection and transmission of information in networks of different voltage levels. Aim: The research presented in the framework of this article is aimed at creating a universal device intended for use in electrical networks of low and medium voltage in order to collect and transmit information about the parameters of electrical energy at the place of installation of the device. Methods: The study was performed with the use of computer modeling techniques developed electronic devices. Results: A functional diagram of the developed device is given, options for its connection to the network for various conditions and requirements are indicated, and recommendations for use are given. Conclusion: The obtained results can be used by power grid companies and industrial enterprises to analyze the condition and efficiency of power grids.

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