Rachid Cherkaoui

Rachid Cherkaoui
École Polytechnique Fédérale de Lausanne | EPFL · Institute of Electrical and Electronic Engineering

PhD, Senior Scientist

About

198
Publications
37,719
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5,543
Citations

Publications

Publications (198)
Article
Full-text available
This paper proposes and experimentally validates a joint control and scheduling framework for a grid-forming converter-interfaced Battery Energy Storage Systems (BESSs) providing multiple services to the electrical grid. The framework is designed to dispatch the operation of a distribution feeder hosting heterogeneous prosumers according to a dispa...
Preprint
Full-text available
The concept of Energy Hub (EH) has been emerged to accommodate renewable energy sources in a multi-energy system to deploy the synergies between electricity and other energy sources. However, the market mechanisms for the integration of the EHs into the energy markets are not sufficiently elaborated. This paper proposes a flow-based two-level distr...
Article
Full-text available
The power flexibility of the proliferating distributed energy resources located in distribution networks could be aggregated and provided to the transmission system. Considering the lack of a framework to help transmission system operator (TSO) to benefit from these potential power flexibility resources, first, the article establishes a framework f...
Article
Full-text available
The paper presents a method for the co-optimization of energy storage systems allocation and line reinforcement in active distribution networks. The objective is to guarantee the capability of an active distribution network to follow a dispatch plan by appropriately coping with the high uncertainties of loads and stochastic renewable generation whi...
Preprint
Full-text available
This paper proposes and experimentally validates a joint control and scheduling framework for a grid-forming converter-interfaced BESS providing multiple services to the electrical grid. The framework is designed to dispatch the operation of a distribution feeder hosting heterogeneous prosumers according to a dispatch plan and provide frequency con...
Preprint
Full-text available
The progressive displacing of conventional generation in favour of renewable energy sources requires restoring an adequate capacity of regulating power to ensure reliable operation of power systems. Battery Energy Storage Systems (BESSs) are considered to be promising assets to restore suitable frequency regulation capacity levels. BESSs are typica...
Article
Full-text available
The paper presents a model-based control strategy for optimal asset management of hydroelectric units in run-of-river hydropower plants. The proposed control strategy aims to operate the unit at the best efficiency while improving water flow management and minimize components wear during frequency containment reserve provision. This approach is des...
Conference Paper
Full-text available
Nowadays, the importance of providing frequency stability to power systems with hydropower units is significantly increasing due to the growing proportion of volatile renewable energy sources. However, the provision of such services, as frequency containment reserve, inevitably increases the wear and tear, decreasing the performance of the hydrauli...
Article
Full-text available
With a continuously growing share of non-dispatchable renewable energy sources in the power mix, flexibility in hydropower provision is becoming fundamental. The major role played by hydropower in frequency regulation in the last years has underlined the possible drawbacks of fast regulation impacting the hydraulic system health. Two of the most pr...
Article
Full-text available
The paper presents the development of a model-based Smart Power Plant Supervisor, a digital tool targeting the optimization of the operation and maintenance of hydroelectric units to improve ancillary services provision to the power system. The paper focuses on a control-oriented modelling methodology which allows integrating the operational parame...
Article
Full-text available
Power systems with large shares of converter-interfaced renewables may be characterised by low grid inertia due to the lack of frequency containment provided by synchronous generators. Battery energy storage systems (BESSs), which can adjust their power output at much steeper ramping than conventional generation, are promising assets to restore sui...
Article
Full-text available
Relying on the power flexibility of distributed energy resources (DERs) located in an active distribution network (ADN), this ADN will be able to provide power flexibility to the upper-layer grid at their point of common coupling (PCC). The power flexibility is defined as additional bi-directional active/reactive powers a resource can provide to th...
Article
Full-text available
This paper proposes a procedure for the optimal siting and sizing of energy storage systems (ESSs) within active distribution networks (ADNs) hosting a large amount of stochastic distributed renewable energy resources. The optimization objective is to minimize the ADN’s day-ahead computed dispatch error. The allocation of ESS is determined while ta...
Article
Large horsepower induction motors play a critical role in the operation of industrial facilities. In this respect, the distribution network operators dedicate a high priority to the operational safety of these motor loads. In this paper, the induction motor starting is modeled analytically and in a semi-static fashion. This model is imbedded in a c...
Article
The support of distributed energy resources (DERs) for providing operational flexibility can be beneficial from the transmission system operators’ (TSOs’) viewpoint. Despite all opportunities, using DERs within an active distribution network (ADN) for providing flexibility brings operational challenges such as lines congestions and excessive voltag...
Article
Full-text available
The paper presents the implementation details and the experimental validation of a linear state estimator based on synchrophasor measurements in a real subtransmission network. The data are provided by 15 phasor measurement units (PMUs) installed in the 125-kV grid of the city of Lausanne, Switzerland. The PMU-based monitoring infrastructure, the t...
Article
Full-text available
This paper presents a method for the optimal siting and sizing of energy storage systems (ESSs) in active distribution networks (ADNs) to achieve their dispatchability. The problem formulation accounts for the uncertainty inherent to the stochas-tic nature of distributed energy sources and loads. Thanks to the operation of ESSs, the main optimizati...
Article
The aggregators are intermediary players at the distribution system level. They manage the financial transactions of resources such as micro-turbines (MTs), photo-voltaic (PV) production systems, flexible demands (FDs), and must-run demands (MDs) in the energy market. Based on the regulation of many transmission system operators (TSOs) in European...
Conference Paper
Full-text available
The paper presents the implementation details and the experimental validation of a linear state estimator based on synchrophasor measurements in a real subtransmission network. The data are provided by 15 phasor measurement units (PMUs) installed in the 125-kV grid of the city of Lausanne, Switzerland. The PMU-based monitoring infrastructure, the t...
Preprint
Full-text available
This paper proposes a procedure for the optimal siting and sizing of energy storage systems (ESSs) within active distribution networks (ADNs) hosting a large amount of stochastic distributed renewable energy resources. The optimization objective is to minimize the ADN's day-ahead computed dispatch error. The allocation of ESS is determined while ta...
Preprint
Full-text available
We design and experimentally validate a real-time control system for battery energy storage systems (BESSs) to provide frequency control and voltage support to power grids. The objective of the control system is to utilize the full power capability of the BESSs to provide ancillary services. We take into account the dynamic capability curve of the...
Preprint
Full-text available
This paper proposes a control method for battery energy storage systems (BESSs) to provide concurrent primary frequency and local voltage regulation services. The actual variable active and reactive power capability of the converter, along with the state-of-charge of the BESS, are jointly considered by the optimal operating point calculation proces...
Article
Full-text available
This paper proposes a control method for battery energy storage systems (BESSs) to provide concurrent primary frequency and local voltage regulation services. The actual variable active and reactive power capability of the converter, along with the state-of-charge of the BESS, are jointly considered by the optimal operating point calculation proces...
Article
Large horsepower induction motors play a critical role as industrial drives in production facilities. The operational safety of distribution networks during the starting transients of these motor loads is a critical concern for the operators. In this paper, an analytical and convex optimization model is derived representing the starting transients...
Article
The distribution network restoration problem is by nature a mixed integer and non-linear optimization problem due to the switching decisions and Optimal Power Flow (OPF) constraints, respectively. The link between these two parts involves logical implications modelled through big-M coefficients. The presence of these coefficients makes the relaxati...
Article
The ever-increasing penetration of Distributed Generators (DGs) in distribution networks suggests to enable their potentials in better fulfilling the restoration objective. The objective of the restoration problem is to resupply the maximum energy of loads considering their priorities using minimum switching operations. Basically, it is desired to...
Preprint
Large horsepower induction motors play a critical role as industrial drives in production facilities. The operational safety of distribution networks during the starting transients of these motor loads is a critical concern for the operators. In this paper, an analytical and convex optimization model is derived representing the starting transients...
Preprint
The distribution network restoration problem is by nature a mixed integer and non-linear optimization problem due to the switching decisions and Optimal Power Flow (OPF) constraints, respectively. The link between these two parts involves logical implications modelled through big-M coefficients. The presence of these coefficients makes the relaxati...
Preprint
Large horsepower induction motors play a critical role in the operation of industrial facilities. In this respect, the distribution network operators dedicate a high priority to the operational safety of these motor loads. In this paper, the induction motor starting is modeled analytically and in a semi-static fashion. This model is imbedded in a c...
Preprint
The ever-increasing penetration of Distributed Generators (DGs) in distribution networks suggests to enable their potentials in better fulfilling the restoration objective. The objective of the restoration problem is to resupply the maximum energy of loads considering their priorities using minimum switching operations. Basically, it is desired to...
Article
Full-text available
Distributed energy resources (DERs) installed in active distribution networks (ADNs) can be exploited to provide both active and reactive power reserves to the upper-layer grid (i.e., sub-transmission and transmission systems) at their connection point. This paper introduces a method to determine the capability area of an ADN for the provision of b...
Preprint
Full-text available
This paper presents a method for the optimal siting and sizing of energy storage systems (ESSs) to be installed into active distribution networks (ADNs) to achieve their dispatchability. The problem formulation accounts for the uncertainty inherent to the stochastic nature of distributed energy sources and loads. Thanks to the operation of ESSs, th...
Conference Paper
Full-text available
In this paper we present an adaptive robust optimization framework for the day-ahead scheduling of Active Distribution Networks (ADNs) where the controlled devices are distributed Energy Storage Systems (ESSs). First, the targeted problem is formulated using a two-stage optimization approach. The first-stage decisions determine the amount of import...
Conference Paper
Full-text available
The flexibility of distributed energy resources (DERs) accommodated in active distribution networks (ADNs) can be aggregated and then used to provide ancillary services to the transmission system. In this context, this paper presents a linear optimization method for the transmission system operator (TSO) to allocate its required active power reserv...
Conference Paper
Full-text available
The ever-increasing requirements for reliability and quality of supply suggest to enable the self-healing features of modern distribution networks. Within the context of Active Distribution Networks (ADNs), new, fast and efficient restoration strategies can be developed relying not only on switching devices to realize load transfer operation, but a...
Conference Paper
Full-text available
In this paper, we consider the provision of primary frequency control by using battery energy storage systems (BESSs). In particular, we use a standard droop-based frequency control for a BESS where the control action (i.e. the BESS power output) consists in the contribution of two additive terms: the regulating power, proportional to the frequency...
Article
Full-text available
This paper addresses the allocation of frequency control services (FCSs) from aggregated resources of active distribution systems (ARADSs) for balancing the transmission system while considering credible contingencies as well as forecast error of loads and generations through scenarios. First the paper introduces a generic framework for modeling AR...
Conference Paper
Full-text available
The paper discusses the model identification, validation and experimental testing of current-to-voltage dynamic circuit models for a grid-connected MW-class battery. The model refers to an utility-scale 720 kVA/560 kWh battery energy storage system (BESS) and is used in a model predictive control framework to forecast the evolution of the battery D...
Article
Full-text available
The ever increasing utilization of sensitive loads in the industrial, commercial and residential areas in distribution networks requires enhanced reliability and quality of supply. This can be achieved thanks to self healing features of smart grids that already include the control technologies necessary for the restoration strategy in case of a fau...
Article
The recent literature discusses the use of the relaxed Second Order Cone Programming (SOCP) for formulating Optimal Power Flow problems (OPF) for radial power grids. However, if the shunt parameters of the lines that compose the power grid are considered, the proposed methods do not provide sufficient conditions that can be verified ex ante for the...
Article
Full-text available
In this paper, we propose a control framework for a battery energy storage system to provide simultaneously multiple services to the electrical grid. The objective is to maximise the battery exploitation from these services in the presence of uncertainty (load, stochastic distributed generation, grid frequency). The framework is structured in two p...
Article
Full-text available
The ever-increasing requirement for reliability and quality of supply suggests to enable the self-healing features of modern distribution networks employing the intelligent measurement, communication, and control facilities of smart grids. In this paper, the concept of multi-agent automation in smart grids is applied to build a self-healing framewo...
Article
Accurate models capable to predict the dynamic behavior and the State-of-Charge (SoC) of Battery Energy Storage Systems (BESSs) is a key aspect for the definition of model-based controls in electric vehicles and in power grid applications of these energy storage systems. In this context, the paper presents an enhanced electrical BESS model capable...
Article
Full-text available
In this paper we present a procedure for the optimal siting and sizing of Energy Storage Systems (ESSs) owned, and directly controlled by network operators of Active Distribution Networks (ADNs). The peculiarity of the proposed planning procedure consists in embedding the grid reconfiguration. We use a recently proposed conditionally exact convex O...
Article
Full-text available
Physics-based models of electrochemical cells are of great interest for the future battery management systems (BMSs), due to their accuracy and capability to predict cell physical states. One of their main disadvantages, when compared to equivalent circuit models, is the fact that they rely on numerous parameters. The identification of these parame...
Article
Full-text available
For a fault occurring in a feeder of an active distribution system, the targeted restoration strategy consists of activating, in a first stage, clusters of nodes supplied each by a unique resource. This resource could be a DG or a tie-switch (tie-line) that provides power from a neighboring feeder. To reinforce the security of supply, in a second s...
Article
For a fault occurring in a feeder of an active distribution system, the targeted restoration strategy consists of activating, in a first stage, clusters of nodes supplied each by a unique resource. This resource could be a DG or a tie-switch (tie-line) that provides power from a neighboring feeder. To reinforce the security of supply, in a second s...
Article
Full-text available
In this paper, we present a new method for the estimation of the prediction-error covariances of a Kalman filter (KF), which is suitable for step-varying processes. The method uses a series of past innovations (i.e., the difference between the upcoming measurement set and the KF predicted state) to estimate the prediction-error covariance matrix by...
Article
This paper proposes a real-time decentralized control algorithm in multi-area active distribution network relying only on dispersed Battery Energy Storage Systems (BESSs). In particular, we propose a zonal control strategy targeting voltage support and line congestion management. The proposed zonal control relies on an accurate dynamic model of BES...
Article
As the power industry considers moving from a deterministic paradigm to a stochastic one to clear the dayahead market in systems with significant stochastic production, the following question arises: how should a stochastic clearing algorithm be formulated? Our analyses indicate that a threestage stochastic approach is clearly superior to a two-sta...
Conference Paper
This paper proposes and experimentally validates a control algorithm for a grid-connected battery energy storage system (BESS) to level the consumption of a group of prosumers and dispatch their aggregated operation. The control strategy is layered in a two-stage procedure: day-ahead and intra-day operation. During day-ahead operation, the load lev...
Article
This paper analyzes the impacts of flexible demands on day-ahead market outcomes in a system with significant wind power production. We use a two-stage stochastic market-clearing model, where the first stage represents the day-ahead market and the second stage the real-time operation. On one hand, flexibility of demands is beneficial to the system...
Article
The paper presents a network partitioning strategy for the optimal voltage control of Active Distribution Networks (ADNs) actuated by means of a limited number of Distributed Energy Storage Systems (DESSs). The proposed partitioning uses a linear programming approach by means of the known concept of voltage sensitivities. Then, two decentralized op...
Article
We propose and experimentally validate a control strategy to dispatch the operation of a distribution feeder interfacing heterogeneous prosumers by using a grid-connected battery energy storage system (BESS) as a controllable element coupled with a minimally invasive monitoring infrastructure. It consists in a two-stage procedure: day-ahead dispatc...
Conference Paper
The paper presents a centralized real-time adaptive and model-based voltage control algorithm for Active Distribution Networks (ADNs). Differently from the available literature, the proposed algorithm merely relies on the control of Battery Energy Storage Systems (BESSs). In this respect, an experimentally model-fitted two-time constant dynamic mod...
Conference Paper
This paper presents the comparison of decentralized and centralized market settings in terms of economic efficiencies, particularly price signals, and operating aspects. The decentralized dispatch consists of an energy auction separated from a contingency analysis. The centralized setting is the conventional economic dispatch. This comparison inclu...
Conference Paper
This paper presents a real-world application of stochastic programming in the Swiss hydro-based system. The seasonal hydrological conditions may cause insufficient market volume to an extent that security criteria (i.e., the criteria determining of reserve amount) may not be met. In this situations, the question arises to what extend the current pr...
Conference Paper
Full-text available
The contribution illustrates a single particle model (SPM) [1] for Lithium-titanate (LTO) cell. For this specific battery technology there are three parameters of the SPM that could not be inferred by the manufacturer's data. Consequently, there is the need to define and solve an optimization problem aiming at minimizing the residuals of the measur...
Research
Full-text available
The paper presents a centralized real-time adaptive and model-based voltage control algorithm for Active Distribution Networks (ADNs). Differently from the available literature, the proposed algorithm merely relies on the control of Battery Energy Storage Systems (BESSs). In this respect, an experimentally model-fitted two-time constant dynamic mod...