Energy function of energy storage element

Is energy storage a static or memory-less function?

Note that although we will use energy storage elements to describe dynamic behavior, this constitutive equation is a static or memory-less function. The constitutive equation permits us to evaluate the generalized potential energy, Ep For this element, potential energy is a function of displacement alone.

Why is Q a generalized potential energy storage element?

It is a generalized potential energy storage element. The displacement, q, plays the same role as the specific entropy and specific volume do for a pure thermodynamic substance: it is sufficient to define the energy in the system. By convention we will define Ep = 0 at q = 0 as shown in figure 4.1.

What is a modulated energy storage element?

The reason for this restriction is that a modulated energy-storage element would mean that the total energy in a system would be a function of the modulating input or set of inputs. Consequently, the total energy in the system would not be equal to the net power flow in across the system boundaries..

Why do we need to know about dependent energy storage elements?

This is a typical consequence of dependent energy storage elements and, as one might expect, in more complex systems the algebraic manipulations can become formidable, even prohibitively so. It would be useful to know about dependent energy-storage elements before attempting to derive equations. How may we do so?

Which energy storage element can be described using an integration operator?

Every energy-storage element which can be described using an integration operator should be. It will require one initial condition to determine its constant of integration, and therefore will give rise to one state variable; energy storage elements which have integral causality are independent.

What are the two energy storage mechanical elements?

The two energy storage mechanical elements can have initial conditions that need to be taken into account in the analysis. A mass can have an initial velocity, which will clearly produce a force, and a spring can have a nonzero rest length, which also produces a force.