First-order probabilistic harmonic power flow

There is an increasing interest in standards and technical literature on the probabilistic characterisation of voltage and current harmonics in multiconvertor power systems. Characterisation requires the expression of input data of the harmonic penetration modelling by random variables and application probabilistic techniques of analysis. A probabilistic method is described for harmonic analysis of a multiconvertor power system which takes into account the interactions between the supply voltage distortions and the converter current harmonics. To reduce computational effort, the proposed method linearises around an expected value region the nonlinear equation describing the system steady-state behaviour. Consequently it offers a faster solution than the one based on probabilistic iterative methods which need Monte Carlo simulation procedures. Numerical applications to a test system are presented and discussed to demonstrate the accuracy and speed of the proposed method.