Ivan Pavić

Role and impact of coordinated EV charging on flexibility in low carbon power systems

The paper analyses the impact of Electric Vehicle (EV) integration into different power systems and their flexibility potential in mitigating the uncertainty and variability of renewable energy sources (RES) generation. The problem is cast as Mixed Integer Linear Programming (MILP) unit commitment, modelling different generation mix/technologies over a number of scenarios. The results, as expected, show that different EV charging strategies have different impacts on power system operation and unit scheduling. In addition, the analyses support the premises that the greater number of EVs, with coordinated charging strategies, can have environmental benefits in terms of reducing CO2 emissions in addition to reducing wind curtailment and system operation costs. These benefits are more obvious in low flexible power systems characterized by dominantly thermal power plants, while they are less pronounced in balanced hydro thermal systems.

A Comprehensive Approach for Maximizing Flexibility Benefits of Electric Vehicles

Increasing variability and uncertainty coming from both sides of the power system equilibrium equation, such as wind energy on the generation side and increasing share of new consumers such as electric vehicles on the demand side, entail higher reserve requirements. While traditional approaches of assigning conventional generation units to maintain system stability can increase operational costs, greenhouse gas emissions, or give signals for new investments, utilizing intelligent control of distributed sources might mitigate those negative effects. This can be achieved by controllable charging of domestic electric vehicles. On the other hand, increasing number of public charging stations gives final users the opportunity to fast charge, making their vehicles an additional source of uncertainty rather than a provider of flexibility. This paper brings a full system assessment of combined effect of slow home charging of electric vehicles together with fast charging stations (both with and without integrated energy storage systems), cast as mixed integer linear programming unit commitment model. The contributions of this paper look into optimal periods when fast charging is beneficial for the system operation, as well as assess the benefits of integrating battery storage into fast charging stations to mitigate the negative effects to power system operation.

Transportation and power system interdependency for urban fast charging and battery swapping stations in Croatia

An increasing penetration of electric vehicles in recent years has been driven by government and municipal subsidies, tax exemptions, parking access priority, as well as by the citizens increased environmental awareness. Electric vehicles indisputably bring benefits to their drivers and society in general, indirectly through global warming and greenhouse gas emissions mitigation and directly through financial savings and cleaner microclimate. However, integration of electric vehicle charging spots at home or work, especially fast charging stations and battery swapping stations, without prior analysis can have a negative effect on power system. In order to predict and eliminate power grid issues before they occur, a detailed analyses should be made through a common understanding of both transportation and recharging needs of electric vehicles users and of the power grid constraints. Power and transportation system interdependency becomes of high value for correct placement and sizing of charging stations and for overall increase of social welfare. This paper analyzes electric vehicles charging needs at the basic level, through both the power system and the transportation system. An urban transmission and power grid in the vicinity of the Croatian capital Zagreb is used as a study case. Driving and electricity consumption curves are compared, locations for charging infrastructure are selected (fast charging spots and battery swapping station) and power grids available capacity is defined.

Electricity markets overview — Market participation possibilities for renewable and distributed energy resources

The main idea of the paper is to provide a detailed analysis of market set-ups in Europe, North America and Australia as well as to define obstacles and potentials for full market integration for renewable and distributed energy resources. Comparing rules and market operational principles from different continents, elaborated through examples of most evolved markets, indicates how different technologies could benefit from offering market products on multiple time frame basis. In this line, recent European documents set a framework for non-discriminatory access to market for all entities. Since benefits for new entrants are maximized in case of co-optimized participation in multiple markets, the paper discusses how implementing segments and concepts from USA and Australian markets could help in achieving this in Europe.

Fast charging stations — Power and ancillary services provision

High penetration of variable renewable sources act as a heavy burden on conventional power system management and operation. Uncertainty in power systems expanded from demand side to generation side as well. Since new sources of imbalances have entered power system, it should be reorganized, automated and modernized. New providers of flexibility should be recognized and used in future power system planning and design. One of the possible technologies that can be used for flexibility provision are electric vehicles. Numerous fast charging stations are installed all over the world and such trend will continue in future. Depending on their operation, charging stations can act as flexibility providers but they can also further degrade systems flexibility if installed without any kind of energy buffer. This paper will present mixed integer linear model for flexibility studies of modern power systems with high penetration of variable renewable sources and electric vehicles. Results clearly show that smart planning of fast charging infrastructure can bring huge benefits to power system concerning costs, emissions, and variable renewable power curtailment.

Building network-enabled smart sensors and actuators

The advent of the new Internet-of-Things (IoT) paradigm in last few years redefined the ways how the small embedded systems can enhance smart sensors and actuators to provide new possibilities in ubiquitously interconnected global world. Although there is a rising tendency in modern low-power embedded system design to provide some kind of IoT functionality out-of-the-box due to the availability of network-aware microcontrollers and system-on-chip (SoC) solutions, there is also a great need to upgrade legacy solutions to fit them into this new paradigm shift. In this article we describe a simple generic framework for upgrading legacy devices, which was built upon the state-of-the-art low cost and low power off-the-shelf hardware components, and open source software. The solution can be easily adapted for various types of smart sensors and actuators. We describe a common set of requirements for building such systems, design decisions reasoning, comparison and justification of HW/SW components choice, and sample demonstration of adaptation and upgrade of the chosen commercial equipment, a device for bubble production at children fun events and similar applications.