Dynamic synchronized phasor measurement based on AM-FM demodulation

Abstract

Precise estimation of synchronized phasors in phasor measurement unit (PMU) is significant for system analysis, control and security. Measurement technique under dynamic conditions is addressed in recent researches. Limitations and criteria for dynamic behaviors are proposed in the new issued IEEE Std. C 37.118-2011 for synchrophasor measurements for power system. In this paper, dynamic characteristics of signals are described as non-stationary signals with amplitude and frequency modulations (AM-FM). A new method for estimating synchronized phasor based on AM-FM demodulation by Energy Operator is presented. In order to avoid the effect of noise, low-pass differentiator is employed. Performance of algorithm is evaluated by simulations and analysis of field data. The result illustrate that the algorithm proposed in this paper improves precision of phasor estimation and reduces response time of PMU, which meets the requirement of the current standard even during dynamic behaviors.