AN EFFECTIVE AND RELIABLE METHOD FOR SINGLE FUEL CELLS EXPERIMENTAL TESTING AND RESULTS COMPARISON: ADVANCED CONTROL TECHNIQUES

摘要

The great interest in Fuel Cell Systems, along with the novelty of the device itself, fostered strong developmentrneffort aimed at attempting to take the steps deemed necessary for future FC plant commissioning.rnIn order to attain all the necessary targets in terms of duration, cost, reliability, performance, integration andrnflexibility, in the relatively short times dictated by market rules, a synergy across the continent is required. Therngreatest effort concerns experimentally validating computational predictions which must demonstrate the abilityrnof the systems to achieve the calculated values of the relevant operational and life parameters. This is a long,rntime and resources consuming activity since all experiments constitute feedback for the design phase thatrnshould improve the system itself thus requiring further experimentation. In order to combine resources tornachieve this ambitious target, a virtual testing facility throughout Europe must be created. Obviously the shiftrnfrom site laboratory to a virtual facility, from enterprise work groups to net actions, from proprietary results tornshared community knowledge requires the adoption of a common language and common testing rules.rnThe Energy System Group of the University of Perugia is currently performing single cell testing. The presencernof different and continuously renewing performers, such as students working in the facility on their MSc or PhDrnthesis, and the need of data exchange among partners in the various research projects, attracted attention to thisrntopic. The authors strongly believe that test parameterisation, procedure definition and advanced controlrntechniques constitute the three main steps toward achieving standardization of test conditions and results.rnAdvanced control techniques issues are dealt with in this part of the paper.rnThe advanced control system for the test facility was developed by the authors in order to reach two mainrnobjectives: an easy and remote setting and modulation of all required parameters to make the cell work at thernchosen conditions; a continuous check of all security parameters in order to reveal breakdowns of the test rig orrndangerous conditions, both for the system and for the operators.rnThe control system works through the continuous repetition of a feedback unit. The operation of this unitrnimplies reading the main data such as cell voltage, temperature, pressure, gas composition, electric load, H2 andrnCO ambient concentration, utilization factors, etc., the measurement of the gap between those values and therntarget values, the required consequent modulation of instruments or even the shutdown of the operation test inrncase of dangerous conditions. During the unit operation, all data are elaborated so that the operators see thernchosen control parameters. At every loop unit, the system modifies the values of the parameters according tornreal time operator input or to a previously set test schedule given as a file input. In this operating mode, it isrnpossible to plan a complete test campaign and make the system work with a predefined procedure comprisingrnthe variation and manipulation of all data.rnThe above mentioned is enormously important for defining the operation characteristics in an automatic,rnrepetitive way. Then, it is possible to plan a start-up or shut-down procedure or other particular operationrnmodes. Standard test procedures can be modelled and settled on the control system and each chosen parameterrncan be monitored and controlled with the software.