Massimo Ceraolo

Control techniques of Dispersed Generators to improve the continuity of electricity supply

It is expected that dispersed generation (DG) will play an increasing role in electric power systems in the near future. Among the benefits that DG can give to the power system operators and to the electricity customers, one of the most attractive is the possibility of improving the continuity of power supply. DG plants can be designed to supply portions of the distribution grid in the event of an upstream supply outage. Techniques for controlling DG plants that use feedback of only locally measurable variables are presented. This solution allows correct system operation and switching between parallel and isolated modes without needing online communication of control signals between the generators. The control technique is described with particular reference to inverter-interfaced systems (micro-turbines, fuel cells). Simulations of sample cases including different size and type of generators are presented.

Modelling static and dynamic behaviour of proton exchange membrane fuel cells on the basis of electro-chemical description

Abstract A simplified dynamical model of a fuel cell of the proton exchange membrane (PEM) type, based on physical–chemical knowledge of the phenomena occurring inside the cell has been developed by the authors. The model has been implemented in the MATLAB/SIMULINK environment. Lab tests have been carried out at ENEA’s laboratories; and a good agreement has been found between tests and simulations, both in static and dynamic conditions. In a previous study [M. Ceraolo, R. Giglioli, C. Miulli, A. Pozio, in: Proceedings of the 18th International Electric Fuel Cell and Hybrid Vehicle Symposium (EVS18), Berlin, 20–24 October 2001, p. 306] the basic ideas of the model, as well as its experimental validation have been published. In the present paper, the full implementation of the model is reported in detail. Moreover, a procedure for evaluating all the needed numerical parameters is presented.

Dynamical Models of Lead-Acid Batteries: Implementation Issues

This paper explains how the lead-acid models described previous paper can be utilized in practice. That paper does not supply detailed information on how to identify the several parameters of the proposed models, and it defines a whole family of models, but does not discuss which model of the family is adequate for a given purpose. These two issues are tackled in this paper. For the first, more complex issue, two options are proposed and discussed: a complete identification procedure involving extensive lab tests and a simplified one that combines information from lab tests and data supplied by the manufacturer. Further simplifications applicable in case of batteries belonging to the same family are presented.

High fidelity electrical model with thermal dependence for characterization and simulation of high power lithium battery cells

The growing need for accurate simulation of advanced lithium cells for powertrain electrification demands fast and accurate modeling schemes. Additionally, battery models must account for thermal effects because of the paramount importance of temperature in kinetic and transport phenomena of electrochemical systems. This paper presents an effective method for developing a multi-temperature lithium cell simulation model with thermal dependence. An equivalent circuit model with one voltage source, one series resistor, and a single RC block was able to account for the discharge dynamics observed in the experiment. A parameter estimation numerical scheme using pulse current discharge tests on high power lithium (LiNi-CoMnO2 cathode and graphite-based anode) cells under different operating conditions revealed dependences of the equivalent circuit elements on state of charge, average current, and temperature. The process is useful for creating a high fidelity model capable of predicting electrical current/voltage performance and estimating run-time state of charge. The model was validated for a lithium cell with an independent drive cycle showing voltage accuracy within 2%. The model was also used to simulate thermal buildup for a constant current discharge scenario.

A General Approach to Energy Optimization of Hybrid Electric Vehicles

This paper approaches the problem of optimizing energy consumption onboard hybrid vehicles in a general way, considering the main issues to be solved in their conceptuality and, therefore, that are often abstracted from the actual structure of the particular drive train that the authors considered. The methods that were described are a harmonization of those used by the authors over the last several years; therefore, although being rather general, they are far from describing the state of the art of scientific literature on this topic. Both parallel and series structures are covered; for either structure, the effect of different functions on management strategies (e.g., pure-electric drive and plug-in recharge capabilities) are discussed. Some more details are supplied in the Case Studies section of this paper, where some of the authors past experiences are reconsidered in terms of the general approach proposed in this paper.

High power Lithium Batteries usage in hybrid vehicles

Hybrid vehicles require an energy storage device capable of delivering or absorbing high specific powers (powers per unit of the device size), and still, in some cases, adequate levels of specific energy.

A parallel-hybrid drive-train for propulsion of a small scooter

The paper presents the results of a two year study regarding the use of an innovative drive-train, having a parallel-hybrid structure, in a small scooter, in which a conventional internal combustion engine is coupled with an electric motor for the vehicle propulsion. The developed architecture enhances the maximum vehicle power, by exploiting the braking energy (by recovering it into the provided electrochemical accumulator), and operating the vehicle in zero emission mode for limited ranges. Moreover, it allows for recharging the inner battery from the electric mains, which is extremely appealing in terms of operating costs. According to the simulation results, the hybridization is able to enhance the maximum power of the scooter by 1.1 kW (around 50%), without changing the fuel consumption, and to allow a pure-electric operation with a range of 15-20 km; when the propulsion power comes only from the onboard batteries, and they are recharged from the electric mains, the operation cost per km is around a quarter the cost of corresponding fuel consumption of a vehicle without hybridization

CAN-LabView based development platform for fine-tuning hybrid vehicle management systems

Objective of this work is to point out the advantages of using a Lab VIEW/spl trade/ platform for the developing of the vehicle management system (VMS) and testing of the overall control system of a hybrid vehicle without the need of a hardware implementation of the VMS. The effectiveness of the proposed methodology is shown by means of its application to two real-life examples.

Microcycle-based efficiency of hybrid vehicle batteries

This paper shows the results of experimental tests carried out on two types of batteries for electric vehicles to evaluate their efficiency when subjected to small cycles (microcycles) around operating points characterised by different states of charge. These efficiency data can de useful for designer of energy manager systems for hybrid-electric vehicles to choose the right operating point for the vehicle storage.

Cost effective storage for energy saving in feeding systems of tramways

This paper evaluates the cost effectiveness of using regenerative braking in a tram line in case of non-reversible substations equipped with battery energy storage. It shows, by the combination of results by numerical simulation model and experimental tests, how it is possible to effectively transform an existing tramway to improve its energy efficiency. Results have shown that also from the economical point of view the proposed solution can be of great interest for the transport company wishful to update its system technology.