Performance and comparison of different phasor calculation techniques for the power system monitoring

Abstract

Day to day to electrical power demand increases very rapidly with linear and non-linear load demands. Especially the nonlinear loads are creating the harmonics in the current and voltage signals. The current and voltage signal values are measured with the phasor measurement unit (PMU) for the proper magnitude and phase angle calculation even in the presence of harmonic components in the signals. The performance of the PMU is depending upon the phasor calculation technique. Different technique/methods are available for the phasor calculation, from the method to method there is difference in the accuracy, phasor computation time and complexity. In this paper various techniques for phasor calculation are presented. For better performance of PMU, more accurate and less computation time for phasor calculation technique is required. But in real time, accuracy and speed both may not satisfied with single technique. Need to find a satisfactory technique, which satisfies the speed of phasor computation and accuracy. In this paper it is proposed that direct phasor estimation technique, which gives the better results in terms of accuracy and time and this method, satisfies the requirements for the dynamic monitoring of power system according to the IEEE std. C37.118.1-2011.

Development and Implementation of Synchronized Phasor Measurements for Dynamic State Power System Monitoring and Fault Identification

“…For the elimination of harmonics in the current waveforms analog lters can be used, but these lters introduce some time lag in the measurements, measurements are not faster, and due to the aging effect the harmonics are not eliminated properly [13]. Instead of analog lters digitalized phasor measurement technique is very useful to get the measurement of the fundamental component magnitude and phase angle [14]. The digitalized phasor measurement techniques are Discrete Fourier Transform (DFT) method, Kalman lter method, Wavelet Transform method, and Taylor Approximation methods are available.…”

Effective monitoring of power system with phasor measurement unit and effective data storage system

“…In ( 6) and (7) shows the phasor values at (N-1) th sample ane N th sample respectively. The direct phasor calculation technique is presented in [20]. In (8) The final Phasor is represented as |X|<θ (8)…”

“…The three-phase voltage measurement is done based on a Direct phasr measurement [20]. The simulated signal and real signal line voltage amplitude is taken as 415 V with a frequency of 50 Hz and each cycle is sampled for 72 points with a sampling frequency of 3600 Hz and the outer for loop with shift register is used to obtain the moving window and the inner for loop is used to obtain the 72 samples.…”

“…Disturbances on the grid can be known by using the rate of change of phase angle [19]. Real and reactive power flow in the line can be determined with phase angle difference between the voltage and current phases [20]. For phasor estimation of voltage and current conventionally many phasor measurement techniques are available.…”

Novel PMU Model for Dynamic State Disturbance Analysis with Effective Data Handling System

“…Different signal analysis methods are presented [13] to monitor and detect the faults in the dynamic state. The conventionally available PMUs use the Discrete Fourier Transform (DFT), and Taylor approximation [14] is used for the Phasor calculation. For better accuracy and fast calculation of phasor, a new DFT-based technique is required and the generated data from this also should be stored in an effective way.…”