M. Dicorato

A regional energy planning methodology including renewable energy sources and environmental constraints

In this paper, a bottom-up energy system optimisation model is proposed in order to support planning policies for promoting the use of renewable energy sources. A linear programming optimisation methodology based on the energy flow optimisation model (EFOM) is adopted, detailing the primary energy sources exploitation (including biomass, solid waste, process by-products), power and heat generation, emissions and end-use sectors. The modelling framework is enhanced in order to adapt the model to the characteristics and requirements of the region under investigation. In particular, a detailed description of the industrial cogeneration system, that turns out to be the more efficient and increasingly spread, is incorporated in the regional model. The optimisation process, aiming to reduce environmental impact and economical efforts, provides feasible generation settlements that take into account the installation of combined cycle power plants, wind power, solid-waste and biomass exploitation together with industrial combined heat and power (CHP) systems. The proposed methodology is applied to case of the Apulia region in the Southern Italy.

A static optimization approach to assess dynamic available transfer capability

This paper deals with the development of a nonlinear programming methodology for evaluating available transfer capability. The main feature of the approach is the capability to treat static and dynamic security constraints in a unique integrated piece of software. The algorithm has been implemented and tested on an actual power system.

Risk-Constrained Profit Maximization in Day-Ahead Electricity Market

The deregulation of the electricity industry has caused for the generation company (Genco) the need of tools for measuring and managing the risk, beyond the classical problem of generating unit scheduling. In this paper, a probabilistic framework for the problem of managing risk faced by Gencos trading in day-ahead energy market is proposed. In particular, a stochastic forecast of electricity price and the technical features of hydrothermal units are considered. The approach is based on an optimization procedure for maximizing expected profits in the presence of risk constraints. Conditional value at risk for the distribution of daily profit is used as risk measure.

A simulation tool for studying the day-ahead energy market: the case of Italy

Many challenging issues arise in the newly deregulated competitive electric power markets worldwide. Instead of centralized decision-making in a monopolistic environment, as in the past, many parties with different goals are now involved and competing in the market. Key questions to address include how to predict load and market clearing price (MCP). In this paper a simulation tool for investigating the wholesale energy market in a compulsory power exchange/ISO environment is proposed. For each generator (customer) a multi-stage nondecreasing (nonincreasing) bidding curve is considered, based on an appropriate set of quantity/price pairs. The proposed approach allows the analysis of several crucial aspects which may significantly influence MCP, profits and market shares. Using published and estimated data, the simulation tool is applied to investigate the main features of the Italian wholesale energy market that involves five main companies, represented by a specific set of generation technologies.

A procedure for evaluating microgrids technical and economic feasibility issues

Microgrids exploitation is one of the most useful and efficient ways of integrating Distribution Generation (DG) technologies. Microgrids allow to realize a coordinate control of different DG facilities, and to provide proper control strategies to the distribution grid. In this paper, economical involvements affecting decisions of realization of microgrids are assessed. Furthermore, a procedure for economical evaluation of microgrids is proposed, aiming to minimize costs in the presence of different constraints. The procedure is applied to a test system representing a cluster of residential final users and services, and various cases are analyzed, in order to account for different choices for energy supply.

PrInCE Lab experimental microgrid Planning and operation issues

This paper aims at describing the experimental Microgrid (μG) built at the Politecnico di Bari within a project funded by the Italian Ministry of Education, University and Research. In particular, the μG will provide a test-bed for research, development and testing devices and components for smart-grid applications. Moreover, it will give the possibility to test new control strategies for the optimal management of internal resources and the connection with the distribution company, in order to ensure the proper operation and the integration with the network in compliance with current connection rules.

Voltage compensation for wind integration in power systems

The fast growth of wind generation leads to concern about its effects on electric grid. The wind power integration needs to be ruled by specific voltage and frequency requirements. As concerns voltage support, wind farm are called to guarantee a reactive power regulation range at point of common coupling (PCC). Moreover, in the presence of voltage dips or fault conditions, wind generators should be able to respect low-voltage ride-through curves to contribute to grid regulation and avoid sudden unbalances. In this paper, different control strategies of wind farm are evaluated, in order to comply with grid code requirements for voltage support. In particular, reactive power and voltage regulation is carried out through generator power factor variation and by static compensation devices as SVCs. Simulations are performed on a wind farm connected to IEEE 14-Buses test system in the presence of grid fault condition.

PV plants for voltage regulation in distribution networks

This paper deals with the development of a centralized nonlinear auto-adaptive controller able to optimize the network voltage profile by managing the reactive power supplied by PV inverters. The control design is based on a realtime optimization procedure involving the sensitivity theory in conjunction with the Lyapunov function and produces the control laws that must be sent to local controllers of PV-inverters. The derived controller is implemented and tested on a MV distribution network.

Pricing criterions in presence of intra- and inter-zonal constraints

Abstract Zonal partitioning is a method for solving the energy market, when network topology is taken into account. The reduction of the network to equivalent nodes representing zones, is unable to assess the intra-zonal flows. This could give rise to questionable and unreliable results. In this paper, a methodology for solving the energy market together with transmission service, when either inter- or intra-zonal congestions occur, is proposed. A double-side auction where both customers and sellers bid prices and quantities is considered. Test results are evaluated using the proposed approach on IEEE-118 bus test grid.

Critical issues in large offshore wind farm design and operation

Interest in the realization of offshore wind farms is growing even in zones where exploitation was considered unprofitable so far. For this reason, studies are needed in order to design suitable methodologies aiming to investigate economic feasibility and control strategies both in steady-state and dynamic conditions. In this work, the analysis of steady-state behaviour and investment concerns of electric system for offshore wind farms is carried out. In particular, the case of a 300-MW offshore wind farm is taken as the reference case in order to investigate issues concerning both design and operation of the electrical system of offshore wind farms.