Applying FPGA-based Chip to Apparent Power and Power Factor Measurement Considering Nonsinusoidal and Unbalanced Conditions

This paper proposes a field-programmable gate array (FPGA)-based integrated circuit (IC) for computing apparent powers and power factors of power systems. In a nonsinusoidal and unbalanced three-phase power system, the calculation of apparent powers and power factors has many definitions. Load characteristics of harmonic and unbalance can not be expressed in the traditional apparent power and power factor, which only consider the fundamental and three-phase balanced sinusoidal conditions. This paper utilizes the FPGA chip to develop the platform to implement the calculation methods of apparent powers and power factors. The proposed design scheme is developed using the very high speed integrated-circuit hardware description language (VHDL), which provides high flexibility and technology independence. This paper discussed the effective power and power factor, the arithmetic power and power factor, and the fundamental power and power factor. The design of filters for the computation of fundamental frequency components is given. ModelSim is used at first to simulate the calculation of apparent powers and power factors to ensure the accuracy of timing and function. Research results show that the designed chip can compute accurately the apparent powers and power factors considering the effects of nonsinusoidal and unbalanced conditions. Key-Words: FPGA, SoC, Power Factor, Harmonic, Unbalanced Power System.