Monitoring and Protection of Power Distribution Networks with IEC 61850-9-2 Standard

In the modern power grid, communication plays a vital role in making the system more reliable and secure. The communications network transfers data between different units to a control center or to Intelligent Electric Devices (IEDs) in order to accurately control or protect the modern power system. The paper discussed possible ways to monitor the measured values for protecting the power system according to IEC 61850-9-2 (sample value). The sequence of the process consists of streaming the sample value packet, decoding it, and phasor extraction and filtering, which are discussed here. To validate the research, Sundom Smart Grid was used as a pilot to measure the values converted to digital form (IEC 61850-9-2) and to stream it to the system through a highly secure communications network. To decode the SV packet, two scenarios are presented in the case study, based on processing useful features of the IEC 61850-9-2 standard-based raw data streamed from the SSG, including μPMU in a range of embedded instruments and a real-time simulator. The main result of this paper is an algorithm for analyzing SV packets and determining whether the network is operating normally.©2020 IET. This paper is a postprint of a paper submitted to and accepted for publication in 15th International Conference on Developments in Power System Protection (DPSP 2020) and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at the IET Digital Library.fi=vertaisarvioitu|en=peerReviewed

Hardware-in-the-loop Testing of Line Differential Protection Relay Based on IEC 61850 Process Bus

The term digital substation refers to the process of managing operations between intelligent primary devices and distributed Intelligent Electric Devices (IEDs) interfaced with a highly secure communications network. The process bus is the first part of the interface between the primary instruments (such as the current and voltage transformers and protection devices) and is an important part of digitalization. This paper describes a method for constructing an interface between measurement instruments and protection devices based on the IEC 61850 standard. Two scenarios are considered to examine the performance of the power system protection in a transmission line between two substations. Both a conventional and an IEC 61850-9-2 (sampled values) approach are implemented to feed the measured values to the protection devices. Trip signals are then also sent to the circuit breakers using IEC 61850-8-1 (GOOSE message). Comparing this method with conventional technology, the outcomes for the digital substation are more accurate and reliable thanks to the rapid reaction of protection devices and the speed at which the trip signal is received. The new process bus method has been tested by implementing a hardware-in-the-loop platform, consisting of a real-time simulator (OPAL-RT eMEGAsim), StandAlone Merging Units (SAMUs), and line differential protection.©2020 IET. This paper is a postprint of a paper submitted to and accepted for publication in 15th International Conference on Developments in Power System Protection (DPSP 2020) and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at the IET Digital Library.fi=vertaisarvioitu|en=peerReviewed

Distributed control strategy for energy storage systems in AC microgrids : towards a standard solution

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Multi-simulation environment for smart grid : co-simulation approach

Wide area measurement and control methods should be employed in modern grids to ensure a more resilient power system. Digital communication technologies play a vital role in such systems, and delays in the communication system can lead to malfunctions in the power system. The integration of the power system and communication network is thus a requirement for implementing smart grids. This paper investigates the possibility of comprehensive integration and discusses the challenges to coupling power system with communication network using continuous and discrete simulation techniques, respectively. The frameworks, platforms, and possible interfaces for a high-performance cosimulation are also presented; the effects of time synchronization and method for obtaining the accrued result are investigated. Finally, existing co-simulation methods are summarized in a table.©2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

Operative factors affecting energy balancing and speed of equalization in battery storage system

Energy storage systems play a significant role in power management systems and control of the modern grid. One of the most challenging issues is controlling storage units in distributed form. This paper presents a possible means of controlling Energy Storage Systems (ESS) through a decentralized approach. Moreover, the balancing and equalization of stored energy in different storage units presents other challenges in such systems; to deal with this, the paper discuss here the factors that affect energy balancing and the speed of the energy balance convergence. A Proportional-Integral (PI) controller is used in the upper control level to generate an accurate reference value for the State of Charge (SoC), and a modified droop control is employed on the lower control level to equalize the energy on the basis of the SoC. To evaluate the control algorithm and to investigate the factors that affect the speed of equalization, this paper considers the result of a case study with three battery storage units.fi=vertaisarvioitu|en=peerReviewed

Principles of power management in a smart microgrid based on Std. IEC 61850

In recent years, the structure of the electrical power system has changed, and all aspects of power generation have shifted towards bidirectional and smart methodology. The Microgrid (MG) as a popular concept for the modern grid and advanced communication techniques play major role in future smart grids. In this regard, this paper presents the principles of MG power management from communication point of view. Moreover, there have been recent efforts to standardize MGs, and it is in terms of these advances that the current paper present the investigation based on IEC 61850 standards. Finally, the hierarchical levels of both the power and communications sides are discussed, and the responsibility of each level is summarized based on the standards.fi=vertaisarvioitu|en=peerReviewed

Design and Analysis of New Harbour Grid Models to Facilitate Multiple Scenarios of Battery Charging and Onshore Supply for Modern Vessels

The main objective of this study is to develop and analyse different harbour grid configurations that can facilitate the charging of batteries for modern vessels and supply onshore power. The use of battery energy storage systems in modern hybrid or entirely electric vessels is rapidly increasing globally in order to reduce emissions, save fuel and increase energy efficiency of ships. To fully utilise their benefits, certain technical issues need to be addressed. One of the most important aspects is to explore alternative ways of charging batteries with high power capacities for modern vessels. The paper presents a comprehensive overview of battery-charging configurations and discusses the technical challenges of each design from the perspective of their practical implementation, both onshore and onboard a vessel. It is found that the proposed models are suitable for vessels operating either entirely on battery storage or having it integrated into the onboard power system. Moreover, the proposed charging models in a harbour area can solve the problem of charging batteries for future hybrid and electric vessels and can open new business opportunities for ship owners and port administrators. The performance of the proposed models is validated by simulating two case studies in PSCAD: slow charging (based onshore) and fast charging (based onboard).fi=vertaisarvioitu|en=peerReviewed