CIRED - Open Access Proceedings Journal

The voltage and current unbalances are serious power quality problems with interaction on each other and mainly affecting low-voltage electricity distribution three-phase systems. In a three-phase system, the current unbalance is due to load unbalance, while it is considered as the main cause of voltage unbalance. The electricity utilities and distribution network operators are responsible for pro... View full abstract»

This study is based on the ongoing evolution of the power grid for supporting a much more flexible and dynamic grid with a high penetration of renewable energy sources and storages. The foreseen applications required for controlling and protecting this new grid are further mapped against the emerging 5G technology, identifying both the challenges as well as the opportunities, by assessing the powe... View full abstract»

The expansion of IEC 61850 outside of the substation is the next step in the evolution of the standard that improves its functionality in order to better serve the smart grid. The study discusses the definition of a routable Generic Object Oriented Substation Event (GOOSE) message, the differences with the conventional GOOSE, and its applications for distribution automation and protection systems. View full abstract»

Overheating of metallic ground screen connections at accessories of single core cables are the root cause of severe insulation failures in the distribution network. The overheating is due to a high transition resistance of the connections combined with high induced currents in the ground screens during operation. For copper screened cables equipped with a metallic laminate, overheating causing fai... View full abstract»

Cyber security deployment first focused on being compliant to standards and regulations. This approach has been very beneficial for the entire industry because it has increased the level of awareness about cyber security even if it may have led to oversimplifications (such as focusing on transmission only, removing serial communications, defining security perimeters etc.). As the electrical grid i... View full abstract»

Electrical energy is one of the most important energy sources in our life. The need for electrical energy is rapidly growing with developing technology and increasing population. Due to the growing population, the cities considerably expanded and the electrical network has to lie within the living spaces. Especially, uses of medium voltage transformers for distribution systems become widespread in... View full abstract»

In power network analysis it is increasingly desirable to implement controller and power systems models within different software environments. This stems from, among other things, an increasing influence of new and distributed control functions within smart grids and a growing influence of market operations. The computation time resulting from the use of multiple simulation environments can cause... View full abstract»

Open ring networks have been commonly used; they have been protected with either phase and earth simple or directional overcurrent protection relays. The biggest drawback of open ring electrical power networks is that a line/cable fault will disconnect the customers that are connected downstream from that fault location until manual or automatic reconfiguration of the network is done. How could we... View full abstract»

Recently, losses reduction gained a great deal of attention in distribution system due to low-voltage level and the high-current passing through the lines, pushing the distribution utilities to improve their profit margins on one hand by reducing the unnecessary operational cost, and improving their delivered power quality on the other hand by maintaining the system reliability, and the continuity... View full abstract»

The protection functions applied for sensitive directional earth-fault protection in compensated medium-voltage (MV)-networks are based on the measurement of residual current and voltage, and the derivation of the resistive operation quantity thereof. In this study, the importance of residual current measurement accuracy on earth-fault protection performance in compensated MV-networks is analysed.... View full abstract»

TNB has developed an asset management framework in accordance with ISO 55001:2014. One of the key elements of the framework is the asset life cycle management. This study presents TNB experience in managing the on-load tap changers (OLTC) over their complete lifecycle to improve performance and reliability. Using failure mode, effect and criticality analysis based on the previous failure data, lif... View full abstract»

The study addresses the application of artificial intelligence (AI), defined as artificial neural networks, in energy distribution. AI is quickly emerging as a valuable tool in decision- making, holding out the promise for systems that can apply, analyse, evaluate and create autonomously. Currently, no published experience exists of applying an AI in network planning on distribution level. The aut... View full abstract»

For a guarantee of durability and reliability in the manoeuvre, the breaking capacity that the contacts must support, and number of operations or manoeuvres required are fundamental parameters to select equipment. The breaking capacity is a critical parameter within the design and application of the auxiliary relay, (Tripping signal, Multiplication of signals, Current amplification, Signal for Ope... View full abstract»

Ageing electrical switchgear infrastructure is a threat to the reliability of power networks. As the cost of downtime continues to rise, engineers and electrical distribution stakeholders need a strategy for either upgrading or replacing ageing switchgear. This study reviews the benefits of investing in an upgrade strategy. Costs and production downtime scenarios are analysed and low- and medium-v... View full abstract»

Medium voltage (MV) networks have numerous of solutions how to perform a neutral point grounding according to demanded characteristic of a ground fault current for relay terminals and safety of people and utilities. Solution with grounding over partial compensation is widely spread in networks with significant capacitive current <italic>I_C</italic> (though not to... View full abstract»

When a low-voltage (LV) DC distribution system installation is realised in a public power distribution network, an extensive specification is required to ensure electrical and equipment safety and compatibility between the existing grids and customer-end installations. The goal of the study is to give to a reader an understanding what is required for safe and reliable operation of the LVDC distrib... View full abstract»

The current transmission and distribution network relies on SF6technology because of its remarkable arc quenching properties and dielectric insulation. However, SF6is a greenhouse gas with an extremely significant impact on global warming. It is one of the six gasses listed in the 1997 Kyoto Protocol designed to lower greenhouse gas emissions worldwide. In addition, as a fluo... View full abstract»

Smart cities provide citizens with information on various urban services and allow them to track the impact of their resource consumption on the overall sustainability of their city. Energy management is one of the most demanding issues within such urban centres owing to the complexity of the energy systems and their vital role. Therefore, significant attention and effort need to be dedicated to t... View full abstract»

Owing to the increasing penetration level of Inverter Based Generation (IBG) over the last years, there has been much effort on the development of IBG models for power system dynamic studies. Therefore, CIGRE and CIRED have established a joint working group CIGRE C4/C6.35/CIRED: ‘Modelling and dynamic performance of inverter based generation in power system transmission and distribution studies’ w... View full abstract»

Modern communication standards and techniques are the way forward in the simplification and improvements of today's protection application. Different communication services in international electrotechnical commission (IEC) 61850 standard Ethernet-based station bus enable possibility to simplify the design of the medium-voltage switchgear. This study discusses the factors related to testing and co... View full abstract»

Low-voltage direct current (LVDC) distribution is considered as one of the new promising technologies for better integration of distributed generation, and supplying local loads in more efficient way compare to AC systems. However, DC protection is still considered as one of the outstanding challenges that holds back the wide deployment of LVDC in the last mile utility applications. Most of existi... View full abstract»

Photovoltaic (PV) grid-connected system becomes one of the most important and promising applications for solar energy, the interfacing of these systems to the grid requires efficient control strategies for operation, control and power quality (PQ) improvement. The operational objectives of PV system are fulfilled by many control modes, during sunlight, the system sends active power to the grid and... View full abstract»

This paper presents the activities of the CIGRE/CIRED C6.25/B5 joint working group (JWG), focusing on the control and automation systems for the future electric networks. This JWG is mainly focused to evaluate the level of automation and control necessary to better manage distribution networks with large penetrations of distributed energy resources, as seen from both the TSO and DSO perspectives. View full abstract»

Electric buses have gained a large public interest lately. In Gothenburg, Sweden, a demonstration project is currently underway where electrical and hybrid electric buses are being tried. This study investigates the impacts on the electrical distribution system from the fast-charging stations used to power the electric buses. Alternatives to mitigate the impacts including demand response (DR) and ... View full abstract»

Along with enhancement of electrical techniques, power quality has become an important issue for both power utilities and users, leading to growing popularity of power quality monitoring systems. Previously, these systems are implemented in the traditional substations. As the smart substation based on IEC 61850 gradually becomes the major technical choice recently, the combination between smart su... View full abstract»