Roberto Caldon

Bio: Roberto Caldon is an academic researcher from University of Padua. The author has contributed to research in topics: Distributed generation & Voltage regulation. The author has an hindex of 19, co-authored 78 publications receiving 1192 citations.

On dynamic load models for voltage stability studies

Abstract: Appropriate modelling of dynamic loads is of primary importance in voltage stability studies. The paper deals with the modelling of a load consisting of a static load plus an aggregate of induction motors. The behavior of three simplified models for such a load configuration is compared. The three models are (A) a generic nonlinear dynamic model of the first order as proposed by Karlsson and Hill, (B) a static exponential load plus a dynamic first-order model for the induction motors, and (C) a static exponential load plus a dynamic third-order model for the induction motors. A power system with a longitudinal structure is chosen as the case-study. It is shown that for the same perturbation (tripping of one of two high-voltage parallel lines) the simulation results are quite different from each other and, in certain cases, only the third-order dynamic model correctly predicts the voltage collapse phenomena at the load bus. An interpretation of the different behavior of the various models is given.

Optimal Control of a Distribution System with a Virtual Power Plant

Abstract: Changes in environmental policies and liberalisation of energy markets lead towards an ever greater level of integration between natural gas/thermal energy and electrical energy distribution services. The availability of new technologies makes it suitable the idea of combining small environmentally compatible generators located close to the loads supplying both thermal and electrical power [1,2]. In this perspective, a number of Distributed Generators (DG) embedded in the distribution grid might be aggregated into a so called Virtual Power Plant (VPP) having the capability of selling both thermal and electrical energy to neighbouring customers [3,4]. The main aim of a VPP would thus be to co-ordinate the different energy resources in order to satisfy the customer requirements with the least generation cost, which means: ƒ to exploit, at any time, all the renewable resources which are stochastically available (wind energy, solar energy, etc.). ƒ when needed, to integrate the generation with fossil resources giving priority to the most economically efficient units. This implies a continuous variation, during the day, of the amount and location within the grid of the generated power which may affect the operation of the grid as regards voltage regulation and line loadings. Within the framework of a distribution system a VPP would thus have to manage the combined production of electric and thermal energy as well as other dispersed sources, if present, with the respect of the network constrains and optimising the profit of the dispersed generation on the basis of the generation costs of the various types of DG, the main grid energy exchange costs and the Distribution System Operator (DSO) wheeling costs. In this paper a cost based optimisation procedure is proposed for harmonising the concurrent operation of DSO and VPP which, although acting in an independent manner, can be co-ordinated by means of suitable economic signals. The present approach for an optimal control of a distribution system undermeans that a sort of local market is established. The DSO optimisation procedure provides to the VPP nodal nodal economic indicators of active and reactive energy. These signals are side results of the DSO optimal network control and depend upon main grid supply prices, distribution losses and network ancillary services requirements. On the basis of such information, the VPP is able to optimise its production in compliance with the network constrains. In order to apply the procedure, however, the DSO needs constantly updated information regarding local generation and network state conditions.

Smart Grid — The New and Improved Power Grid: A Survey

Abstract: The Smart Grid, regarded as the next generation power grid, uses two-way flows of electricity and information to create a widely distributed automated energy delivery network. In this article, we survey the literature till 2011 on the enabling technologies for the Smart Grid. We explore three major systems, namely the smart infrastructure system, the smart management system, and the smart protection system. We also propose possible future directions in each system. colorred{Specifically, for the smart infrastructure system, we explore the smart energy subsystem, the smart information subsystem, and the smart communication subsystem.} For the smart management system, we explore various management objectives, such as improving energy efficiency, profiling demand, maximizing utility, reducing cost, and controlling emission. We also explore various management methods to achieve these objectives. For the smart protection system, we explore various failure protection mechanisms which improve the reliability of the Smart Grid, and explore the security and privacy issues in the Smart Grid.

For the Grid and Through the Grid: The Role of Power Line Communications in the Smart Grid

Abstract: Are Power Line Communications (PLC) a good candidate for Smart Grid applications? The objective of this paper is to address this important question. To do so, we provide an overview of what PLC can deliver today by surveying its history and describing the most recent technological advances in the area. We then address Smart Grid applications as instances of sensor networking and network control problems and discuss the main conclusions one can draw from the literature on these subjects. The application scenario of PLC within the Smart Grid is then analyzed in detail. Because a necessary ingredient of network planning is modeling, we also discuss two aspects of engineering modeling that relate to our question. The first aspect is modeling the PLC channel through fading models. The second aspect we review is the Smart Grid control and traffic modeling problem which allows us to achieve a better understanding of the communications requirements. Finally, this paper reports recent studies on the electrical and topological properties of a sample power distribution network. Power grid topological studies are very important for PLC networking as the power grid is not only the information source but also the information delivery system-a unique feature when PLC is used for the Smart Grid.

Management and Control of Domestic Smart Grid Technology

Abstract: Emerging new technologies like distributed generation, distributed storage, and demand-side load management will change the way we consume and produce energy. These techniques enable the possibility to reduce the greenhouse effect and improve grid stability by optimizing energy streams. By smartly applying future energy production, consumption, and storage techniques, a more energy-efficient electricity supply chain can be achieved. In this paper a three-step control methodology is proposed to manage the cooperation between these technologies, focused on domestic energy streams. In this approach, (global) objectives like peak shaving or forming a virtual power plant can be achieved without harming the comfort of residents. As shown in this work, using good predictions, in advance planning and real-time control of domestic appliances, a better matching of demand and supply can be achieved.