Liana Cipcigan

Cardiff University | CU · Institute of Energy

The development of intelligent strategies to manage electric vehicle charging process is the key for fostering a proper diffusion of electric vehicles at customer premises. The presence of renewable generation and the exploitation of vehicle-to-grid can enhance this process. In this paper, two procedures are proposed for optimizing electric vehicle...

There is an increasing interest to penetrate low carbon vehicles into the transport system. Take the Great Britain (GB) as an example, the number of electric and plug-in hybrid vehicles will make up to at least half of new vehicle sales. Electric vehicles (EVs) are expected to contribute to the ancillary services of the frequency response because E...

Two-inputs adaptive IEEE multi-bands power system stabilizer (PSS4B) was developed for oscillations damping control in power systems. Two supplementary loops based on model reference (MR) adaptive control were added to the typical PSS4B design. The MR has the same loops’ parameters of the typical PSS4B, and hence, avoiding a complex tuning process....

Integration of more renewable energy resources introduces a challenge in frequency control of future power systems. This paper reviews and evaluates the possible challenges and the new control methods of frequency in future power systems. Different types of loads and Distributed Energy Resources (DERs) are reviewed. A model representation of a popu...

The role of ancillary services related to the frequency control have become increasingly important in the smart grids. Demand Side Response is a competitive resource that can be used to regulate the grid frequency. This paper describes the use of heat pumps and fridges to provide ancillary services of frequency response so that to continuously bala...

Commercial buildings have been identified as a major contributor of total global energy consumption. Mechanisms for collecting data about energy consumption patterns within buildings, and their subsequent analysis to support demand estimation (and reduction) remain important research challenges, which have already attracted considerable work. We pr...

In this paper, a review of the classifications of power system oscillation modes, as well as power system stabilizer (PSS) design structures, is proposed. Four major oscillation modes and their effects on power system stability have been investigated and analyzed, and the critical elements affecting each mode, frequency range, and PSS application h...

Many efforts are recently being dedicated to developing models that seek to provide insights into the techno-economic benefits of battery storage coupled to photovoltaic (PV) generation system. However, not all models consider the operation of the PV – battery storage system with a feed-in tariff (FiT) incentive, different electricity rates and bat...

a developed control is proposed for the population of Water Heater Devices to provide different dynamic Frequency Services. The hierarchal control is based on two decision Layers, the aggregator Layer and the device control Layer. The aggregator Layer receives States of devices and enables/disables the device control Layer. It enables the populatio...

a developed model of the Thermostatically-based controllable loads (TCLs) is proposed for a hierarchal Demand Side Frequency Response (DSR). The model involves three layers based on Markov chain, Fuzzy Logic, and Particle Swarm Optimization (PSO) method. Layer 1 is the local Markov population of the TCLs, Layer 2 is the Fuzzy/Markov-based Frequency...

The integration of electric vehicles (EVs) will affect both electricity and transport systems and research is needed on finding possible ways to make a smooth transition to the electrification of the road transport. To fully understand the EV integration consequences, the behaviour of the EV drivers and its impact on these two systems should be stu...

An adaptive deadbeat (ADB) controller was developed to investigate its capability in providing a fast frequency response to an electrical power system. This controller was developed to meet the requirements of the National Grid System Operability Framework (SOF), which requires frequency to be accelerated in line with a fast rate of change of frequ...

A Local Energy Management System (LEMS) is described to control Electric Vehicle charging and Energy Storage Units within built environments. To this end, the LEMS predicts the most probable half hours for a triad peak, and forecasts the electricity demand of a building facility at those times. Three operational algorithms were designed, enabling t...

A model-based approach is described to forecast triad periods for commercial buildings, using a multi-staged analysis that takes a number of different data sources into account, with each stage adding more accuracy to the model. In the first stage, a stochastic model is developed to calculate the probability of having a “triad” on a daily and half-...

The use of renewable energy sources and energy storage systems is increasing due to new policies in the energy industries. However, the increase in distributed generation hinders the reliability of power systems. In order to stabilize power systems, a virtual power plant has been proposed as a novel power grid management system. The virtual power p...

Accurate information regarding the uncertainty of short-term forecast for aggregate wind power is a key to efficient and cost effective integration of wind farms into power systems. This paper presents a methodology for producing wind power forecast scenarios. Using historical wind power time series data and the Kernel Density Estimator (KDE), prob...

Recent advances in the type and variety of sensing technologies have led to an extraordinary growth in the volume of data being produced and led to a number of streaming applications that make use of this data. Sensors typically monitor environmental or physical phenomenon at predefined time intervals or triggered by user-defined events. Understand...

The developments of large-scale renewable energy cause significant challenges for the operation of power system. Demand Side Response (DSR) based Thermostatically Controlled Loads (TCLs) may offer a broad range of potential benefits on system operation and reliability. This paper investigates the modelling of aggregated small loads, such as Heat Pu...

This paper presents a decentralized scheduling algorithm for electric vehicles charging. The charging control model follows the architecture of a Multi-Agent System (MAS). The MAS consists of an Electric Vehicle (EV)/Distributed Generation (DG) aggregator agent and “Responsive” or “Unresponsive” EV agents. The EV/DG aggregator agent is responsible...

Electric vehicle (EV) market penetration is expected to increase in the next few years. Transport electrification will affect both the road transport and the electric power network, as EV charging will be influenced by events that take place on the road network (such as congestion, weather, etc.) which subsequently have an impact on the potential l...

An increase in greenhouse gases (GHGs) is driving significant changes in both the power and transport systems. Electric vehicles (EV) are a promising solution to reduce carbon dioxide (CO2) emissions. However, EV charging will increase the electric load demand posing various challenges to distribution networks operators, such as load variation, vol...

In this paper, unbalanced power flow calculations were used to study the effects of stochastically integrated Distributed Energy Resources (DER) into a distribution network. The considered DER were Electric Vehicles (EVs), Air Source Heat Pumps (ASHPs), and Photovoltaic arrays (PVs). Daily profiles of residential loads and DER were synthesized with...

In this paper, the charging loads of electric vehicles were controlled to avoid their impact on distribution networks. A centralized control algorithm was developed using unbalanced optimal power flow calculations with a time resolution of one minute. The charging loads were optimally reallocated using a central controller based on non-linear progr...

As the number of electric vehicles increases, the impact of their charging on distribution networks is being investigated using different load profiles. Due to the lack of real charging data, the majority of these load impact studies are making assumptions for the electric vehicle charging demand profiles. In this paper a two-step modelling framewo...

According to the U.K. Department for Transport, the 97 % of transport energy consumption comes from the usage of oil. Therefore, a fuel diversification is needed to improve the energy security, and plug-in electric vehicles (PEVs) seem promising in giving an alternative solution. However, PEV owners need electric power from the grid in order to rech...

This paper presents an analysis of the simplified model of the Great Britain (GB) power system for 2030 projections. Electric Vehicles (EVs), Battery Energy Storage System (BESS), and Fly-Wheel Energy Storage System (FESS) are connected in the primary frequency control loop. PD -like Fuzzy Logic controller (PDFLC) is used as a secondary frequency c...

The UK's energy system is majorly centralised but the move from a centralised energy system to a decentralized one could be significant, reshaping the entire system. The penetration of Localised Energy Resources (LER) on the distribution networks will have significant effect on voltage profile. The impact of LER on low voltage distribution network...

A generalized model of a Microgrid in an island mode is proposed for assessing the system power and frequency performances. This Microgrid (MG) includes a diesel backup generator along with a number of Distributed Energy Resources (DES): Wind Turbine Generator (WTG), Photovoltaic System (PV), Fly- Wheel Energy Storage system (FESS), and Battery Ene...

The simplest solution to electrification of the drivetrain is to remove the internal combustion engine (ICE). Battery electric vehicles (BEVs) operate on electricity only and the main components are primarily a high voltage (HV) battery, an electric motor and a motor controller. The distance driven in charge depleting (CD) mode is classified as the...

Traditional approaches to transmission system security assessment use deterministic criteria e.g. the application of 'N-1' or 'N-2' circuit depletion under prescribed heavy system loading conditions. However, such worst-case deterministic approach does not provide explicitly an assessment of the probability of overloading the system, and the likeli...

The growth of vehicle electrification will make the electric power systems to face new challenges as the load profile changes. Charging the EVs will increase the electricity demand and may cause new peaks. However, the nature of this new type of load offers flexibility that can be used to achieve a variety of goals, including a reduction of the cha...

With an increase in the number of monitoring sensors deployed on physical infrastructures, there is a corresponding increase in data volumes that need to be processed. Data measured or collected by sensors is typically processed at destination or "in-transit" (i.e. from data capture to delivery to a user). When such data are processed in-transit ov...

Smart grids are expected to play a central role in any transition to a low-carbon energy future, and much research is currently underway on practically every area of smart grids. However, it is evident that even basic aspects such as theoretical and operational definitions, are yet to be agreed upon and be clearly defined. Some aspects (efficient m...

An agent-based control system that coordinates the battery charging of electric vehicles in distribution networks is presented. The objective of the control system is to charge the electric vehicles at times of low electricity prices within distribution network technical constraints. Search techniques and neural networks are used for the decision m...

The continuous growth and evolve of vehicle electrification causes the electric power systems to confront new challenges, since the load profile changes, and new parameters are being set. With the number of EVs gradually rising, problems may occur in technical characteristics of the network, like bus voltages and line congestion [1]. Therefore, it...

Wind power is anticipated to be the dominant Renewable Energy Sources (RES) in the UK by the year 2020. It is estimated that, there will be 41 GW of operational offshore wind in the UK beyond the 2020s. This wind penetration would likely increase the excess of electricity production. In this paper the Great Britain (GB) energy system was modelled a...

This paper models the energy systems of Great Britain (GB) and Greece in EnergyPLAN for the year 2020. EnergyPLAN is an analysis tool that simulates energy systems on a national scale. Future alternative scenarios were developed considering smart charging of Electric Vehicles (EVs). The model was run with a range of Renewable Energy Sources (RES) i...

Road transport today is dominated by oil-delivered fuels and internal combustion engines and such a high level of dependence on one single source of primary energy carries strategic, climatic and economic risks [1]. Electric mobility offers an opportunity for diversification of the primary energy sources used in transport, but also brings new risks...

With an increasing interest in Electric Vehicles (EVs), it is essential to understand how EV charging could impact demand on the Electricity Grid. Existing approaches used to achieve this make use of a centralised data collection mechanism - which often is agnostic of demand variation in a given geographical area. We present an in-transit data proc...

This paper explores the geographical and policy context for an emergent business model from Better Place to deliver battery electric car mobility in Denmark. It argues that the combination of radically different technologies and a highly complex multi-agency operating environment theoretically provide the conditions and requirements for such an eme...

Battery charging of electric vehicles (EVs) will increase the power demand in distribution networks. It is anticipated that this will cause voltage drops, thermal overloads and an increase in losses. The severity of the impact will depend on the EV owners' behaviour. A generic three-phase low voltage (LV) residential distribution network model was...

Power system security is defined as the ability of a power system to maintain supply without unduly allowing network variables to stray from prescribed ranges. Traditionally, security has been assessed using deterministic criteria e.g. 'N-1' or 'N-2' under prescribed severe system loading levels. However, such worst-case deterministic approach does...

Three approaches for grid integration of Electric Vehicles (EVs) through a Virtual Power Plant (VPP) concept are introduced. A classification of these different ways for realizing a VPP based on the control structure, resource type, and the aggregation approach is discussed. This is followed by a description of the three VPP approaches, which are r...

Electric Vehicles are anticipated to have a considerable percentage of the vehicle market sales in the forthcoming years. The additional energy requirements for charging their batteries may affect the network operation, in terms of stability and reliability, especially when these are synchronized with the system peak demand. This issue will present...

The effect of domestic charging of electric vehicles (EVs) on electricity demand at a national level was addressed. A study case was created to investigate how different charging regimes (i.e. control policies) and EV-uptake levels will affect the electricity demand of Great Britain (GB) and Spain in 2030. Charging rates, battery capacities, and ba...

An agent based control system that manages the charging of electric vehicle batteries according to distribution network constraints and electricity market price signals, is described. The system is adapted to the EV-ON platform and Microgrid equipment of Tecnalia-Lab. A case study is defined to evaluate the behaviour of the control system and the r...

The MERGE project is concerned with the development of a management and control concept which would facilitate the large-scale integration of electric vehicles with the electric grid. The Virtual Power Plant (VPP) is a concept developed for the effective grid integration of distributed energy resources (DERs). Many DERs have insufficient capacity,...

An increase in the penetration level of EVs will increase the power demand in distribution networks. This is due to the charging of the batteries of these vehicles. This may cause thermal overloads, voltage drops and an increase in losses. These impacts will be affected by the behaviour of the owners of EVs. The impacts of EVs on a typical LV netwo...

This paper describes a Virtual Power Plant, containing aggregated micro-generation sources and Electric Vehicles as mobile loads. A UK generic distribution network is used to build a VPP comprising several micro-grids. EV and micro-generation penetration levels are projected for the year 2030, based on previous studies. A multi time period optimiza...

Battery charging of Electric Vehicles (EVs) will increase the power demand in distribution networks. It is anticipated that this will cause voltage drops, thermal overloads and an increase in losses. These impacts will be affected by the behaviour of the owners of EVs. A typical 3-phase LV residential distribution network model is used to evaluate...

A realistic model for a novel saturable core superconducting FCL (SCFCL) prototype is presented, and incorporated into time-domain power simulation software PSCAD™/EMTDC™. The present work incorporates non-linear material properties data of the magnetic core with inductance to produce a limiting effect on the line current in real time. The novelty...

A future perspective micro-grid with a medium-term prediction for 2030 is described. The present state of intentional islanding is briefly reviewed. Distributed Generators (DGs) and Electric Vehicles (EVs) to sustain the local distribution system in the event of interruption of supply are considered. Projections regarding their availability are pre...

The technical challenges related to the market penetration of electric vehicles (EVs) in low voltage (LV) distribution networks are addressed. Steady state voltage profile of LV networks under different EV aggregation levels and penetration scenarios is investigated. A UK generic LV distribution network model and load demand figures from the electr...

Technical challenges concerning microgrids are identified. Differentiation between grid-connected and islanded mode is made, while literature based solutions are presented. The concept of Virtual Grid is introduced and a microgrid model is used as part of a generic Low Voltage Distribution Network. PSCAD/EMTDC and IPSA+ models of the microgrid are...

Micro-generation has the potential of reducing CO 2 emissions from the power sector. This study investigates the emissions performances of some cases of domestic microgeneration during operation. By comparison to the conventional generation options, savings of 10-45% were found, depending on the energy mix. Waste heat recovery by the micro-CHP was...

The paper presents an ontology model, developed with knowledge based editor, Protigi 3.3.1, for wind turbines' condition monitoring. The ontology model proposed by the authors, describes the wind turbine components, developed a knowledge base, and can be used as the basis of fault detection and diagnosis system to reduce cost per kWh of generation....

Concerns over global warming and high oil prices are expected to lead to a continuous increase in electricity generated by distributed renewable energy sources and small-scale embedded generators (SSEGs). This increase in SSEG will pose numerous technical challenges for distribution network operators. The small-scale energy zone (SSEZ) concept seek...