Statistical analysis of voltage harmonic distortions for a commercial load

This paper presents an approach for investigating the statistical behavior of voltage harmonic distortions on a commercial load. Stochastic process tools are proposed for analyzing the problem of total harmonic distortion (THD). Voltage signals are used to perform the study. Indices such as probability and time means are employed for verifying condition of stationarity of the process and whether both processes present similarity. Field measurements obtained from a commercial load are used to assess test results. The statistical analysis permits to establish a typical time period, which better characterizes installation harmonic distortions. Also, it makes possible to verify whether an installation phase is representative to the others on a harmonic study simulation. Results to the studied load indicate that indices are different for three types of standards. Only one of them is fulfilled.