Investigation of active power measurements in harmonic conditions

An investigation of active power measurements using 4 different accuracy level watt meters when specific harmonic conditions (different harmonic currents, 4 values of fundamental power factor (PF) and no phase shift between harmonic voltages and harmonic currents) in the system was performed. Expected active powers during harmonic environments based on IEEE Std. 1459-2010 were calculated to be reference powers. Results show the reference and working level watt meters provide measured active powers perfectly while the general measuring watt meter gives a large error especially when a harmonic content is high but a PF is very low. Thus, uses of active power values in harmonic conditions obtained from watt meters need to be careful particularly those obtained from general measuring watt meters.