Finding All DC Operating Points of Nonlinear Circuits Based on Interval Linearization and Coordinate Transformation

The interval branch and bound algorithm based on interval Newton (IN) operator has been applied to the problem of finding all direct current operating points of nonlinear circuits. Many techniques and modifications have been proposed to enhance its computational performance. In this work, the method has been modified by replacing the IN operator used for sharpening interval solution box by the contraction operator based on interval linearization with coordinate transformation. A prototype of the proposed method has been implemented in MATLAB environment. Its performance has been evaluated by testing with some test nonlinear circuits containing diode and bipolar transistors. The results indicate that the proposed technique can considerably reduce the number of search boxes and improve the computation time.