Data Acquisition Systems for Monitoring and Control of Photovoltaic Generators

none5This paper aims to describe two intelligent systems, microprocessor based, capable of monitoring, both locally o remotely, more photovoltaic strings. In particular, the electronic board called CS097 helps to detect environmental parameters such as temperature and solar radiation and to calculate average power and energy produced by the solar system, in order to monitor the efficiency and electricity production of the photovoltaic field. It can control up to four photovoltaic strings, acquiring voltage and current values for each string. Transducers, installed on the same board, detect currents lower than 20 amps and voltages lower than 1000 V. The acquired data have a maximum error of 1% compared to true current and voltage values generated by the strings. It’s also provided a galvanic isolation between the measuring circuits and the acquisition ones. The CS083 and CS088 electrical boards, instead, work as an alarm system which indicates a critical condition in case of an electrical continuity loss or a not-justified rapid variation of the voltage read on each string.Proceeding of Fourh International Conference on Sensing Technology ICST 2010, Univ. Salento (Lecce, Italy) June 3 – 5 2010; pp. 205-210, ISBN 978-0-473-16942-8.Romanello, Daniele; Lay-Ekuakille, Aimè; Cavalera, Giorgio; Tempesta, Francesco; Visconti, PaoloRomanello, Daniele; LAY EKUAKILLE, Aime; Cavalera, Giorgio; Tempesta, Francesco; Visconti, Paol

Requirement Analysis of a Signal Database for Power Plant Automation Signals

The signal lists used for the control and automation system design of Wärtsilä Power Plants are today made with a spreadsheet software-based configuration tool. The problems with this tool are difficult data maintenance, a large manual workload and traceability of the data of configured signal lists. The maintenance problems are caused by larger power plant sizes, stricter customer requirements and scattered information in different spreadsheet software-files. To solve these problems, a database solution is planned to be developed. In this thesis, the requirements of the database are analyzed, functional descriptions are made and a high-level model of the database solution is created. The main stakeholders of the database system have been identified and interviews have been held with all of them to gather requirements and get information of current problems related to the creation of the signal lists. The development work is done in close cooperation with the Wärtsilä Power Plants R&D department, project management and control system suppliers. Theory of database design and requirements management is collected from scientific literature. This theory is used to identify requirements in the early phases of the database development and in the creation of a conceptual model of the database. The goal was to collect the main requirements, create solutions for current problems and to identify possible solutions for the planned database. The results show the large amount of signal data that is today scattered in different sources. Reasons for problems in power plant project work and control system design have been identified and the main requirements for the database solution have been classified. The planned database functionalities are modelled and possible solutions to fulfill the signal list configuration work are presented. New findings of connectivity to other information systems and lifecycle management of the signal design are brought up to meet future requirements of the power plant signal configuration work.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

MMI, SCADA and ALARM philosophy for disturbed state operating conditions in an electrical utility

A project report submitted to the Faculty of Engineering, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Engineering. Johannesburg 1995.Advances in digital computing technology make it possible to improve the design of the Man Machine Interface (MMI), SCADA and ALARM modules used in electrical utility control centres. to overcome the problem of control staff data overloading. A possible solution is proposed, based on-an explicit representation of a disturbed power system state in addition to quiescent conditions. The structure of modem SCADA, installations is analysed in terms of the computing power of full graphic workstations, the quantities of element data delivered to the control room and the capabilities of intelligent remote terminal units. This analysis indicates that existing designs for the presentation of SCADA data need to change to solve the data overloading-problem. The proposed philosophy moves the focus of attention from the element level up to the device level by grouping and dividing all elements into categories at the RTU and linking them to their parent device, Control staff are notified graphically on the one-line displays, next to the device in question, of the existence of abnormal elements by category. The element state details for the device are only displayed on demand, resulting in a 95% reduction of alarm text messages. Suggestions are made as to the software functions needed at tbe RTU and the workstation to assist with the display of system data. Lastly racommendations are offered to reduce maintenance by standardising and pre-ordering device element data.AC201

The design of micro-processors for digital protection of power systems

Imperial Users onl

LANSIM and its applications to distributed EMS

Distributed energy management systems (EMS) open up a host of alternative design options. Simulation plays an important role in evaluating performance and in comparing alternative designs. Currently all the proposed distributed EMSs are local area network (LAN)-based. A LAN simulator, LANSIM, has been developed. To illustrate the application of LANSIM, comparisons are made with different distributed EMS configurations, different LAN technologies (Ethernet and FDDI), and different Ethernet implementations.published_or_final_versio