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»

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»

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»

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»

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»

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»

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»

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»

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»

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»

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»

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»

Considering time varying nature of load in conventional distribution system, network reconfiguration is combinatorial complex optimisation problem. In this study, a hybrid configuration of particle swarm optimisation (PSO) method with ant colony optimisation (ACO) algorithm called hybrid PSO–ACO algorithm is presented for optimal network reconfiguration in distribution network in the presence of d... View full abstract»

Increasing distributed photovoltaic (PV) systems can lead to voltage violations and overloading of grid assets in distribution grids. This raises the necessity to consider the future growth of installed PV capacity for the planning process of distribution system operators (DSOs). This study proposes the combination of a solar roof potential analysis and grid integration studies at the medium-volta... 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»

An electricity supply smart contract was developed and demonstrated to perform pre-time-of-use price negotiation between demand and generation and post-time-of-use settlement and payment. The smart contract was demonstrated with 1000 loads/generators with usages simulated using lognormal probability distributions. It combines payment of deposit, negotiation of price based on estimates, settlement ... View full abstract»

Transformers are important equipment in distribution networks which their optimal siting and sizing is one the important issues in planning and operation of distribution networks. In traditional methods, the optimal capacity of transformers is determined considering the average load consumption and temperature. In the presence of non-linear loads, the current and voltage distortions are increased ... View full abstract»

A new solution for the phase and earth fault directional detection used in fault passage indicators (FPI) is presented in this study.The solution is based on several low-power voltage sensors using capacitor on bushing, on head cable or resistive sensors. The principle of the phase directional detection remains on the conventional principle of protection relays (ANSI 67). The main algorithm improv... View full abstract»

We cover some practices and methods in creating effective cyber security architectures for substation and distribution automation systems and products which are robust enough to withstand cyber-attacks and resilient enough to recover in the event of security compromise and keeping device functional and executing its core functionality even during attack. This is achieved by a defence-in-depth stra... 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»

In order to have a viable design of low-voltage direct current (LVDC) protection devices like circuit breakers and fuses, it is important to design them for the correct short-circuit ratings keeping the network configuration in account. In this study, fault characteristics for different future LVDC network configurations are simulated (PLECS) (PLECS is a simulation platform for power electronic sy... View full abstract»

Southeast Asia's power systems face huge challenges – from reliability issues, over steeply growing energy demands to questions related to the change in the generation and demand matrix. In addition to these challenges, plans to integrate large amounts of intermittent renewable energy sources are put forward. Last but not least providing energy access for all citizens remains a challenge for many ... View full abstract»

Breaking down the distribution network into several microgrids with relative balance of supply/demand using the capacity of the embedded distributed energy resource (DERs) is a promising solution to manage the complex distribution systems. Two modes of the operation – normal and self-healing – could be considered. Normal mode relates to the minimisation of the operation costs of the distribution s... 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»

This study presents the first performance results of a large battery energy storage system (BESS) that is connected to a medium-voltage distribution network and used simultaneously by multiple stakeholders. This study presents the background of the purpose of a BESS as part of the Nordic power system and markets, and the functionalities it is able to perform. The first test cases ran in the fall 2... View full abstract»

The presence of distributed generation (DG) in modern distribution networks has caused a paradigm shift in their operation and protection philosophy. In this study, the adequacy of existing protection schemes in the Hellenic distribution system is assessed, examining a representative medium-voltage network with particularly high DG penetration. The deficiency of the applied protection practices so... View full abstract»

Earthing design requires the synthesis of a number of highly variable parameters, many of which are outside the direct control of the designer. Although probabilistic analysis enables designers to recognise this fact it has rarely been applied to the earthing system design. Nevertheless, the fundamental need to manage the risk of electric shock is met by quantifying actual risk levels using probab... View full abstract»

Enedis, the main French distribution system operator (DSO) (ex-ERDF), conducted an innovation challenge opened to start-ups and innovative small and medium enterprises (SME) companies in order to detect promising solutions able to support the ‘next generation field technician’. A field test programme was conducted with the selected innovative companies with the aim of experimenting prototypes of n... View full abstract»

The operation of distribution networks with wide-scale, actively managed, distributed energy resources (DERs) has generated a demand for more sophisticated study tools, development aids, and test facilities to analyse technical operational issues related to the bi-directional power flow on distribution networks. This study discusses the challenges of modelling large distribution networks, characte... 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»

Battery energy storage systems can assist distribution network operators (DNOs) to face the challenges raised by the substantial increase in distributed renewable generation. A challenge is that these resources are intermittent and often ‘invisible‘ to the DNO. If not monitored, the aggregate size of small embedded generation resources can cause thermal wearing of distribution assets and voltage e... 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»

This study describes the operation of the adaptive power restoration scheme, a unified algorithmic approach to implementing self-healing networks in the event of an unplanned outage (fault) on the high voltage (6.6kV & 11kV) network. The schemes are deployed across all three distribution areas that UK power networks own, serving London power networks, the southern power networks and East o... 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»

The subject addressed is as analysis of a feedback of a fault circuit indicator performance based on data collected from the pilot projects in South East Asia and from the field tests provided by St Petersburg suburb power distribution utility ‘Lenenergo’, Russia. 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»

One of the most challenging discussions in distribution companies is power quality. Harmonics is one of power quality issues which generated in any non-linear electrical/electronic systems. The presence of harmonics in distribution networks can lead to various problems in terms of performance and operation. High-pressure sodium (HPNa) lamps are currently the main lamps used in public lighting. How... 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»

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»

Brazil has a national integrated electrical system with more than 120,000 km of overhead transmission lines (OHTL), owned by transmission and distribution companies. Current inspection approaches are obsolete and expensive or do not cover all items to be inspected. In spite of having many academic-related works, the use of unmanned aircraft system (UAS) for inspection remains as a challenge for re... View full abstract»

In this study, the implementation of virtual power plant (VPP) as a means to coordinate the use of distributed resources for different control objectives by transmission system operator and distribution system operator is described. In order to illustrate the concept, a range of illustrative studies demonstrating the application of VPP concept on a real 11 kV system in Brixton will be presented, u... View full abstract»

The focus on enhancing the reliability and efficiency of the power grid has led to the implementation of the Smart Grid concept. This concept is based on the deployment of automation, namely advanced distribution automation (ADA) applications, and control technologies relying on the availability of parameters such as voltage, current, temperature etc. acquired from certain nodes of the grid. For a... View full abstract»

Here, a fractional-order proportional–integral–derivative (FOPID) controller is implemented for frequency deviation control of a proposed hybrid fractional-order power generation and energy storage system. This control strategy is designed based on coordination control of fractional-order fuel cell and supercapacitor bank models in a hybrid renewable energy system with stand-alone application. The... View full abstract»

The installation of phasor measurement units (PMUs) by Enduris, one of the distribution network operators in the Netherlands to monitor their 50 kV ring distribution grid has resulted in increased observability of the power flows and voltages. However, with the increased observability, there is a need to analyse the distribution grid based on the data generated by the PMU monitoring system. This s... View full abstract»

With the boost of smart meter installations, the technical difficulties for demand response (DR) have been overcome a lot. For years, numerous DR programmes have been in operation to enhance the system reliability. Meanwhile, some DR programmes run on the profit of participating power market, like arbitraging between the wholesale market and the retail market in regions with a deregulated power ma... View full abstract»

This study aims to present a comprehensive distribution loss analysis in typical distribution network of Mashhad in medium and low-voltage networks, which can be useful for network operators. Also the experience with efforts for distribution loss reduction in a residential and a commercial section in Mashhad are reviewed. Unfortunately, non-technical loss is the major part of distribution loss in ... View full abstract»

This study evaluates the transient behaviour of the pole-mounted distribution transformers (DT) following fast-front lightning strikes arising the medium-voltage (MV) network and the low-voltage (LV) network. The effects of installing surge protection devices (SPD) in the LV terminals of the pole-mounted DT are also evaluated. For these purposes, the transient studies were performed using the EMTP... View full abstract»

In December 2015, a confirmed cyber-attack targeting several electric power utilities in Eastern Europe has resulted in a power outage that impacted hundreds of thousands of utility customers. This event strongly indicates that distribution system operators (DSOs) systems are vulnerable and are high risk of being targeted. With many new connected components inside the DSO's systems and readily ava... View full abstract»

One of the major problems in optimal operation of the distribution networks is harmonic emission in the frequency range of 2–150 KHz or supra-harmonics. Some of the problems of the emission and harmonic immunity in the frequency range of 2–150 KHz are noted in IEC61000-4-19 standard. The testing and measurement methods of power quality are expressed in IEC61000-4-30 standard. In CISPR-16 standard,... View full abstract»

Sein Island (French Brittany) has an isolated and autonomous network (Fig. 1) that is not connected to the continental electricity grid. It is essential on these islands is to ensure the highest possible degree of robustness and quality-of-service. Currently, power is provided almost solely by diesel generators (gensets) with a high kWh cost and greenhouse gas ... View full abstract»