STATISTICAL ASSESSMENT OF RANDOM HARMONIC LEVELS IN SYSTEMS WITH VARYING ADJUSTABLE SPEED DRIVE LOADS

摘要

This paper presents an analytical approach for the statistical assessment of random harmonic voltage and current levels in distribution systems with many randomly varying nonlinear loads such as adjustable speed drives (ASDs). A probabilistic ASD model is developed to determine the statistical parameters of the generated harmonic currents due to the randomness in the drive loading level. The Central Limit Theorem is applied to get analytically the probability density functions (pdfs) of the magnitude of system harmonic voltages and currents. An improvement of the analytical method is achieved to account for system voltage profile. Monte Carlo simulation is performed for justifying the method.