ABSTRACT
An electrical network is describable by a system of algebraic and differential equations known as the primary system of equations obtained by applying the Kirchhoff’s current and voltage laws and the element v–i relations. In the case of linear networks, these equations can be transformed into a system of linear algebraic equations by means of the Laplace transformation, which is relatively simple to manipulate. In a given network, a minimal set of its branch variables is said to be a complete set of state variables if their instantaneous values are sufficient to determine completely the instantaneous values of all the branch variables. For a linear time-invariant nondegenerate network, it is convenient to choose the capacitor voltages and inductor currents as the state variables. A great advantage in the state-variable approach to network analysis is that it can easily be extended to time-varying and nonlinear networks, which are often not readily amenable to the conventional methods of analysis.
