Probability characteristics of fundamental and harmonic sequence components of randomly varying loads

The paper gives computed probability density characteristics for the resultant sequence currents in a three-phase system for several specified load-current probability patterns. Loads are considered to be connected in star, with or without neutral connection, or delta. Results are applicable to both fundamental and harmonic components of load and sequence currents and may be used to assess either the probability of the resultant amplitude of the sequence currents, with many loads on the system, or the probable time duration for any sequence-current magnitude with one load in each phase varying in a prescribed manner over an appropriate period of time. Applications of the characteristics to some typical system problems are examined.