Energy Flow in Interconnected Systems

Add to your list(s) Download to your calendar using vCal

• Professor Jan Willems (K.U. Leuven)
• Friday 05 February 2010, 14:00-15:00
• Cambridge University Engineering Department, LR5.

If you have a question about this talk, please contact Dr Ioannis Lestas.

We examine what is meant by the power and the energy which a physical system exchanges with its environment. The systems which we consider interact through terminals, as wires for electrical circuits, and pins for mechanical devices. Associated with each terminal, there are variables through which the system interacts with its environment. For circuits, these variables are current and potential, and for (one-dimensional) mechanical systems, position and force. Systems are interconnected by sharing variables at the interconnected terminals. We define a port as a set of terminals that satisfy certain conditions, which we call the port-Kirchhoff laws. For ports, and only for ports, we define the power and the energy which flows into a system. Since a port involves more than one terminal, power and energy are not `local’, but involve `action at a distance’. Moreover, we cannot speak about the power and the energy flow along any set of terminals. We discuss the nature of ports for electrical and mechanical systems, and derive an expression for energy that is not frame dependent. We end by proving that a connected RLC circuit forms a 1-port. This implies that in open systems energy rarely flows between subsystems along the interconnected interface.

This talk is part of the CUED Control Group Seminars series.

This talk is included in these lists:

• Cambridge University Engineering Department, LR5
• All Talks (aka the CURE list)
• CUED Control Group Seminars
• Cambridge Centre for Data-Driven Discovery (C2D3)
• Cambridge University Engineering Department Talks
• Centre for Smart Infrastructure & Construction
• Chris Davis' list
• Featured lists
• Information Engineering Division seminar list
• Interested Talks
• School of Technology
• Signal Processing and Communications Lab Seminars
• Trust & Technology Initiative - interesting events
• bld31
• ndk22's list
• rp587

Note that ex-directory lists are not shown.