Impact of Non Linear Loads on Nodal Prices in a Radial Distribution System

Abstract

Deregulation has brought the variation in the electrical power prices according to the market rules. Here nodal pricing technique is considered for the calculation of cost of power loss and energy at each bus. The system’s functioning condition and nature of load show the impact on pricing.  Non-linear loads growth has caused the distortion in the power factor and the increase in the losses due to higher harmonics. Under such conditions, the distribution system network operator (DNO) must determine the impact of harmonics on the system operation and develop an efficient pricing scheme that considers the impact of harmonics on nodal prices. A non-linear load with third, fifth and seventh harmonics are considered. Analysis has been carried out for IEEE 33 bus test system. Effect of harmonics on the calculation of nodal prices is presented with the formulation of harmonic load flow using forward backward sweep. Here marginal loss coefficients (MLCs) are calculated and are used to get these prices. IEEE 33 bus RDS is considered for this study and the results are observed for constant power (CP) and realistic ZIP loads.