This paper describes a new probabilistic method for harmonic analysis of multiconverter power systems which allows the evaluation of the percentiles of the voltage and current harmonics, that are the probabilistic quantities of interest in the most recent international recommendations or standards. In order to reduce the computational efforts, the proposed method firstly linearizes the well known nonlinear equation system describing the steady state behavior of multiconverter power systems and then calculates the mean and other moments of the voltage and current harmonic probability density functions: finally, the percentiles of interest are obtained applying the Pearson distributions, which require the knowledge of only the first four moments of the probability density functions. Numerical applications to a test system are also presented and discussed to demonstrate accuracy and speed of the proposed method.