Real Time Tracking of RMS Quantites in Three-Phase Systems under Nonsinusoidal Conditions

The paper presents a real time measurement technique for tracking rms quantities of fundamental and harmonic components under nonsinusoidal conditions in a three-phase system based on the efficient least squares method. The proposed technique allows real time accurate measurements of the rms values and phase angles of the fundamental and harmonics present in distorted unbalanced three-phase waveforms. The effectiveness of the proposed measurement method is demonstrated by computer real time simulation and practical implementation in the laboratory establishes thee potential of this method. It is demonstrated that the proposed method can provide an accurate measurement of fundamental and harmonic rms quantities in a pollution measured waveform. Due to the fast response and accurate measurement, the proposed method makes it suitable for use in real time applications. Consequently, this technique can be used for control applications, protection applications, and power quality monitoring of power systems.