A method of approximate steady-state analysis for non-linear networks

The paper describes a method whereby the fundamental and third-harmonic quantities in the steady-state solution of a network containing certain non-linear elements may be obtained approximately. The method consists of three stages: (a) A first approximation to the fundamental-frequency solution, usually accurate to within 10%. (b) A third-harmonic solution (generally within 15%) using an equivalent circuit which is dependent on the first fundamental solution. (c) A correction to the fundamental solution, using third-harmonic quantities, which brings its accuracy to within about 3%. Adaptations of some standard techniques of solving linear steady-state problems for use with this method of analysis are described.