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In this paper, a novel locational marginal price (LMP) policy for distribution system with significant penetration of distribution generation (DG) in competitive electricity market is presented. This new LMP method is based on remunerating DG units for their participation in reduced amount of energy losses in distribution systems brought about by participation of all DG units in supplying demand. Also, this method is combined with an iterative solution. This approach provides an efficient tool for distribution companies (DISCOs) to estimate the state of the system in the next step which other existing approaches of LMP fail to provide this system state estimation. Finally, in order to expand LMP method and provide effective prediction method for DISCOs to estimate the day-ahead state of the system, ANN tool is employed to predict the market price and demand for the next 24 h. This LMP prediction is a powerful operational tool for DISCO to exert its control over private DG units. However, prediction methods contain error. Therefore, uncertainty modeling is implemented for modeling the effect of error in prediction on the LMP calculation for the next day.

In this paper, total harmonic distortion (THD) minimization of the output voltage of multilevel inverters is discussed. An efficient approach in reducing the harmonic contents of the inverter's output voltage is THD minimization. In multilevel inverters with a fundamental frequency switching strategy (each switch turning on and off once per output cycle), the switching angles can be selected so that the output THD is minimized (such as the so-called optimal-minimization-of-THD strategy). To obtain the optimum switching angles, an optimization algorithm is applied to the output-voltage THD. In three-phase multilevel inverters, the optimization algorithm is commonly applied to the phase voltage of the inverter. This results in the minimum THD in phase voltage but not necessarily in the line-to-line minimum THD, whereas in three-phase applications, the line-voltage harmonics are of the main concern from the load point of view. In this paper, using the genetic algorithm, a THD minimization process is directly applied to the line-to-line voltage of the inverter. This paper is based on a seven-level inverter. To verify the simulation results, a seven-levelcascaded-H-bridge-inverter-based hardware prototype, including an ATMEGA32 AVR microcontroller, has been implemented. Both simulation and experimental results indicate superiority of this approach over the commonly used phase-voltage THD minimization approach.Index Terms-Genetic algorithm (GA), line-voltage total harmonic distortion (THD), multilevel inverter, optimal minimization of THD (OMTHD), THD minimization.

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