David Pozo

European Commission JRC · C3

In this letter, two formulations of the linear convex hull of an energy storage system (ESS) are presented. The convex hulls are constructed from the standard parameters of an ESS, namely the charging and discharging power rate capacities, charging and discharging efficiencies, and energy capacity limits. These formulations provide the tightest lin...

In this letter, two formulations of the linear convex hull of an energy storage system (ESS) are presented. The convex hulls are constructed from the standard parameters of an ESS, namely the charging and discharging power rate capacities, charging and discharging efficiencies, and energy capacity limits. These formulations provide the tightest lin...

We analyze the potential benefits that energy storage systems (ESS) can bring to distribution networks in terms of cost, stability and flexibility. We propose an optimization model for the optimal sizing, siting, and operation of storage systems in distribution grids. A DistFlow formulation is used for modeling the AC power flow. The ESS model is b...

The European Union (EU) has a natural gas storing capacity of approximately 1100 TWh in underground reservoirs. This energy capacity, in the form of natural gas, is one million times larger than the world's largest electricity battery project. Underground gas storage (UGS) facilities offer large-scale, long-duration energy storage solutions that ai...

Electric power systems and the companies and customers that interact with them are experiencing increasing levels of uncertainty due to factors such as renewable energy generation, market liberalization, and climate change. This raises the important question of how to make optimal decisions under uncertainty. This paper aims to provide an overview...

Power system network topology reconfiguration can reduce the cost of relieving network congestion. In this work, N-1 Security-Constrained Optimal Power Flow that utilizes substation reconfiguration and busbar splitting is introduced. A column-and-constraint generation decomposition technique is proposed to accelerate the solution process. The propo...

Mathematical models are just models. The desire to describe battery energy storage system (BESS) operation using computationally tractable model formulations has motivated a long-standing discussion in both the scientific and industrial communities. Linear BESS models are the most widely used so far. However, finding suitable linear BESS models has...

Power grids are enormous and complex engineering systems. Electricity produced from generators is transferred through power networks to loads that consume it. Like many other assets, electricity trading can be organized via markets, driving the operation of power grids. While the general principles for market design can support the foundation of el...

Active distribution networks (ADN) have grown considerably in recent years. Distributed energy resources present in ADNs can provide flexibility to the power system through TSO/DSO coordination, i.e., at the interface node (feeder) between the transmission and distribution network. This paper addresses the issue of calculating multi-period flexibil...

Worldwide commitments to net zero greenhouse emissions have accelerated investments in renewable energy resources. The requirements for operating and planning power systems are becoming stringent because of the need to take into account the uncertainty associated with renewable generation. Several modeling frameworks that consider the inherent unce...

Mathematical models are just models. The desire to describe battery energy storage system (BESS) operation using computationally tractable model formulations has motivated a long-standing discussion in both the scientific and industrial communities. Linear BESS models are the most widely used so far. However, finding suitable linear BESS models has...

With climate change, we have been witnessing more frequent extreme weather events causing increasingly common large-scale power outages. It is essential and urgent to improve power system resilience, which also substantially impacts the resilience of dependent infrastructures, such as water and health systems. This work investigates the enhancement...

Virtual power plants (VPPs) are considered the next generation of power plants where they aggregate the distributed energy resources (DERs) aiming to participate in different electricity markets. Many of the aggregated DERs within the VPP have ambiguous future performance. Thus, to maximize profit in the electricity market, VPP needs offering curve...

The need for flexible networks is an emerging challenge for power system operators (SO). The use of additional support, such as demand response (DR), must be quantified in order to offer a reliable service, given that this information is vital for demand aggregators. Thermostatically controlled loads (TCLs) are one of the most promising options amo...

Results of four-year experimental trials of a Gaming Lab for understanding power markets are presented in here. The main goal of Gaming Lab was to illustrate the effects of strategic behavior on electricity markets, recognize pricing mechanisms and analyse the issues that emerge from competitive electricity markets. Evidences for reproducibility of...

The optimal transmission switching problem (OTSP) is an NP-hard problem of changing the topology of a power grid to obtain an improved dispatch by controlling the operational status of the transmission lines. Exact solution techniques based on mixed-integer programming (MIP) like branch-and-bound (B&B) guarantee identifying global optimal solutions...

Buildings are responsible for a large portion of the world’s energy consumption. Any measure that can be taken to optimize the use of energy related to them must be considered. Demand Side Management (DSM) can be used to shave demand peaks and to avoid bootstrapping highly polluting fast ramp-up generators. This though brings a control problem that...

Cooperative Game Theory has recently attracted attention in power systems research as a tool for expansion planning analysis. However, this analysis is usually performed in an ex-post manner, i.e., planning and operation decisions are separated from the allocation mechanisms themselves. This paradigm implies selecting an allocation rule to share th...

This paper presents an analysis of the stability and quality of the distributed generation planning problem’s investment solution. A two-stage stochastic programming model is used to find the optimal distributed generators’ installed capacities. We emphasize the design of scenarios to represent the stochasticity of power production from renewable s...

With the recent advent of technology within the smart grid, many conventional concepts of power systems have undergone drastic changes. Owing to technological developments, even small customers can monitor their energy consumption and schedule household applications with the utilization of smart meters and mobile devices. In this paper, we address...

This paper addresses the problem of building an affordable easy-to-setup synchronized multi-view camera system, which is in demand for many Computer Vision and Robotics applications in high-dynamic environments. In our work, we propose a solution for this problem - a publicly-available Android application for synchronized video recording on multipl...

In recent years, mechanisms of cooperation in power systems have attracted increasing attention from academia and industry. Such mechanisms require sharing the benefits of cooperation among participants based on some rational and obvious principles. In this regard, Cooperative Game Theory (CGT) provides a rich theoretical background for the analysi...

Most of the new technological changes in power systems are expected to take place in distribution grids. The enormous potential for distribution flexibility could meet the transmission system's needs, changing the paradigm of generator-centric energy and ancillary services provided to a demand-centric one, by placing more importance on smaller reso...

Demand flexibility is the capacity of demand-side loads to change their consumption at any instant. It makes electricity more affordable by helping customers to use less power when prices are high. On the other hand, demand flexibility can also help to increase the reliability of the power grid when is highly stressed, by reducing demand for power...

In this paper, the potential of reducing the electricity cost with the help of energy storage and controllable loads on the Russian retail electricity market is studied. The retail electricity market in Russia features different price categories, allowing consumers to reduce expenses with proper planning. Approximately 2/3 of the cost in flexible p...

The optimal transmission switching problem (OTSP) is an established problem of changing a power grid's topology to obtain an improved operation by controlling the switching status of transmission lines. This problem was proven to be NP-hard. Thus, different solution techniques have been proposed, that each has its advantages. These include mixed-in...

Recently, chance-constrained stochastic electricity market designs have been proposed to address the shortcomings of scenario-based stochastic market designs. In particular, the use of chance-constrained market-clearing avoids trading off in-expectation and per-scenario characteristics and yields unique energy and reserves prices. However, current...

The integration of energy systems such as electricity and gas grids and power and thermal grids can bring significant benefits in terms of system security, reliability, and reduced emissions. Another alternative coupling of sectors with large potential benefits is the power and transportation networks. This is primarily due to the increasing use of...

Given the rise of electric vehicle (EV) adoption, supported by government policies and dropping technology prices, new challenges arise in the modeling and operation of electric transportation. In this paper, we present a model for solving the EV routing problem while accounting for real-life stochastic demand behavior. We present a mathematical fo...

Power systems incrementally and continuously upgrade their components, such as transmission lines, reactive capacitors, or generating units. Decision-making tools often support the selection of the best set of components to upgrade. Optimization models are often used to support decision making at a given point in time. After certain time intervals,...

In this paper, we propose a three-stage robust generation and transmission expansion planning model considering generation profiles of renewable energy sources (RES) affected by different long-term climate states. Essentially, we extend the broadly utilized two-stage modeling approach to properly consider partial information of climate states with...

This paper presents an analysis of the stability and quality of the distributed generation planning problem's investment solution. The entry of distributed generators power based on non-conventional energy sources has been extensively promoted in distribution grids. In this paper, a two-stage stochastic programming model is used to find the optimal...

This work presents an optimization framework based on mixed-integer programming techniques for a smart home’s optimal energy management. In particular, through a cost-minimization objective function, the developed approach determines the optimal day-ahead energy scheduling of all load types that can be either inelastic or can take part in demand re...

The fast growth of communication technology within the concept of smart grids can provide data and control signals from/to all consumers in an online fashion. This could foster more participation for end-user customers. These types of customers do not necessarily have powerful prediction tools or capability of storing a large amount of historical d...

Although local protection methods can perform well at speed, in a real network where network uncertainties are unavoidable, these methods may result in inaccurate performance. Therefore, the use of other methods, such as wide area protection, can lead to more accurate results because of using comprehensive information via telecommunication links. I...

Equilibrium analysis is crucial in electricity market designs, with Nash equilibrium recognized as the most powerful one. Its most prominent hindrance, however, is an efficient methodology to compute an equilibrium point in large-scale systems. In this work, a Column-and-Constraint Generation (CCG) algorithm is proposed to tackle this challenge. Mo...

The admission planning problem in the inpatient service aims to provide patient access and to guarantee expected levels of bed utilization. However, uncertainty in the patient’s length of stay and bed availability challenge the accomplishment of that objective. This research addresses the off-line admission planning problem with uncertain length of...

There is a growing interest in the integration of energy infrastructures to increase systems' flexibility and reduce operational costs. The most studied case is the synergy between electric and heating networks. Even though integrated heat and power markets can be described by a convex optimization problem, prices derived from dual values do not gu...

The dynamic behavior of active distribution networks has caused a lot of difficulties for the conventional coordination between protective devices. To overcome these coordination challenges, adaptive protection schemes (APSs) are provided as a solution. APS can protect different network states (NSTs) by changing settings where it is needed. Frequen...

Electric vehicles (EV) charging scheduling in parking lots has been a hot topic in recent years. Instead of simply starting the charging process with the entrance of the EVs, a parking lot operator can decrease the cost of buying electricity in real-time, when prices are low. However, this decision-making process involves randomness in both price a...

Power transmission network physically connects the power generators to the electric consumers extending over hundreds of kilometers. There are many components in the transmission infrastructure that requires a proper inspection to guarantee flawless performance and reliable delivery, which, if done manually, can be very costly and time taking. One...

This study proposes an optimal day-ahead (DA) electricity market offering model for a virtual power plant (VPP) formed by a mix of renewable distributed energy resources along with energy storage, such as electric vehicles. Two sources of uncertainty are considered, namely, wind power generation, modelled by an uncertainty set, and DA market price,...

The fast growth of communication technology within the concept of smart grids can provide data and control signals from/to all consumers in an online fashion. This could foster more participation for end-user customers. These types of customers do not necessarily have powerful prediction tools or capability of storing a large amount of historical d...

Erroneous data of the power network parameters can have a massive impact on the quality of the power system state estimation. In general, existing databases for state estimation are used assuming that data is trustful. However, this is not always the case. Erroneous parameters can induce wrong state estimations or mistakenly indicate bad data measu...

The enormous technological potential accumulated over the past two decades would make possible to change the operating principles of power systems entirely. The consequent technological evolution is not only affecting the structure of the electricity markets, but also the interactions between Transmission System Operators (TSOs) and Distribution Sy...

Equilibrium analysis is crucial in electricity market designs, with Nash equilibrium recognized as the most powerful one. Its most prominent hindrance, however, is an efficient methodology to compute an equilibrium point in large-scale systems. In this work, a Column-and-Constraint Generation (CCG) algorithm is proposed to tackle this challenge. Mo...

Over the last years, gas-fired power capacity investments in electricity networks have increased in many countries due to its low-rate of greenhouse gas emissions and the continuous reduction in the natural gas price. Besides, new power-to-gas technologies have attracted attention in the sector as an alternative for harvesting large shares of renew...

We present a distributionally robust optimization (DRO) approach for the transmission expansion planning problem, considering both long- and short-term uncertainties on the system demand and non-dispatchable renewable generation. On the long-term level, as is customary in industry applications, we address the deep uncertainties arising from social...

Effective admission planning can improve inpatient throughput and waiting times, resulting in better quality of service. The uncertainty in the patient arrival and the availability of resources makes the patient’s allocation difficult to manage. Thus, in the admission process hospitals aim to accomplish targets of resource utilization and to lower...

In this work, we compared the performance of the ordinary Newton-Raphson method for calculating power flows against three quasi-Newton methods: chord, “good” and “bad” Broyden's methods. First, we illustrated and compared the performance of each method on systems of equations of different sizes. Secondly, we compared these methods on power flow cal...

State estimation is one of the fundamental power system tools used in the determination of system state variables based on measurements. Current approaches for state estimation problems rely only on direct measurement and pseudo-measurements related with electric parameters only. In this work, we introduce a methodology for the inclusion of weather...

Voltage stability is a vast subject, which covers a substantial area in power system analysis, such as uniform voltage profile, reactive power balance, and feasible operation of the power system. The study and understanding of voltage stability are not only crucial but also very helpful in the safe operation of a power system. This paper presents a...

The need for secure and flexible operation of distributed power systems and the decline in prices for Li-ion batteries have made energy storage deployment a viable option. The electric energy storage units’ characterization (including Li-ion batteries) currently utilized for power system operation and planning models relies on two major assumptions...

The rapid adoption of Li-ion batteries in electric vehicles, merchant storage applications, and as providers of ancillary services to the electric grid, requires the development of tractable and accurate models for their reliable operation. For such operations, it is common practice to use generic and ideal storage mathematical models, i.e., models...

In this paper, a method for calculating critical electric energy price and critical daily distance traveled in an electric vehicle (EV) is proposed based on the life cycle cost theory. The life cycle cost of an EV and its equivalent internal combustion engine vehicle (ICEV) are determined by considering initial investment cost, carbon emissions tax...

The development of electric vehicles (EVs) has led to an increase in the number of electric vehicle charging stations (EVCSs). However, the lack of proper charging infrastructure can demote the expansion of the electric transportation fleet. In this regard, reducing the impact of EVCS on the distribution networks and choosing optimal charging operat...

The need for secure and flexible operation of distri- bution power systems with renewable generation and the decline in prices for battery systems have made energy storage projects a viable option. The storage units characterization currently utilized for power system models rely on two significant assump- tions: the storage efficiency and power limit...

In this paper, we present a framework for analyzing cross-border power interconnection projects based on Cooperative Game Theory. Compared to existing studies, we not only quantify the benefits of interconnections and suggest cost-benefit allocation techniques, but also analyze the stability of the allocations, which is a crucial aspect in regions...

The characterization of current electric energy storage units used for power system operation and planning models relies on two major assumptions: charge and discharge efficiencies are constant, and the power limits are independent of the electric energy storage state of charge. This approach can misestimate the available storage flexibility. A det...

Smart grids as digitalized electricity networks can provide many new capabilities such as managing an enormous number of distributed energy resources, supporting large quantities of renewable energy productions even in small-scales, as well as enabling demand side to participate more actively in demand response (DR) programs. In the depth of digita...

This paper presents a model for the electricity and gas expansion planning (E&GEP) problem. The gas network is modeled by non-linear equations based on the steady-state physical description of the gas system. The electricity network is modeled by the linearized power flow equations. Investment in new transmission lines, pipelines, compressors, and...

Wind power generation has increased significantly in the recent decade due to its low-cost and sustainable nature. Determining the rated wind speed (RWS) of turbine is the main factor for generation of electrical energy using wind generators. Till now, no relationship has been reported for determining capacity value using the power curve of the win...

Microgrids (MG) were first conceived as smallscale grids working in an islanding-mode. However, they can be operated in a grid-connected mode too. MGs can easily host a large number of paralleled-connected distributed generations (DGs). The increased penetration of the renewable energy sources (RESs) is raising new concerns about redesigning the ro...

In this paper, a mixed integer linear formulation for problems considering time-of-use-type constraints for uninterruptible services is presented. Our work is motivated by demand response problems in power systems, in which certain devices must remain online once they are switched on, along with a certain number of periods. Classically, this kind o...

In this paper, a mixed integer linear formulation for problems considering time-of-use-type constraints for uninterruptible services is presented. Our work is motivated by demand response problems in power systems, in which certain devices must remain online once they are switched on, along with a certain number of periods. Classically, this kind o...