Description in English
The main purpose of the project is the development of new methods and algorithms for stability evaluating of electrical circuits by means of variational methods, especially stability of DC operating points. There can be more DC operating points in a circuit. Some of them are unstable and non-observable in the real circuit. However, the identification of such unstable operating points is a serious problem because the present circuit theory does not have effective tools for explicit decision if the designed DC operating point is stable or not. It is not obvious how to define the circuit stability when omitting reactance elements. M.M.Green proposed a definition of so called potential stability of DC operating point. He created an algorithm to identify unstable points based on this definition. However, this algorithm is not able to identify all unstable operating points. Necessary (in)stability condition is one of the unsolved problems which solution is expected by the world manufacturer of integrated circuits. The purpose of this project is to investigate this new area of the circuit theory by other methods. We want to use variational principles known from analytical dynamics and thermodynamics of nonequilibrium processes.

Keywords
DC stabilita, stejnosměrný pracovní bod, potenciální stabilita, variační metody.

Key words in English
DC stability, operating point, potential stability, variational methods.