Universal Grid Analyzer Development
This project will allow better characterization of the grid power quality and dynamics through the introduction of a newly developed Universal Grid Analyzer (UGA). The UGA is a real-time, highly accurate, and GPS synchronized power grid monitoring instrument. It can function as a power quality analyzer, phasor measurement device, and noise analyzer. The outputs include harmonics, voltage sag, swell, noise level, and phasors. A prototype UGA was built at our PowerIt laboratory as shown in Fig. 1.
Fig. 1 The prototype UGA
Using a high signal-to-noise ratio (SNR) sampling circuit and a patent pending flexible synchronous sampling algorithm, the UGA is an ultra-high-resolution measurement instrument, particularly for phasor estimation (0.005 degree angle error) and frequency estimation (0.00015 Hz frequency error). This is indicated in Fig. 2, which shows the measurement accuracy comparison between the prototype UGA and FDRs.
In addition, the UGA can analyze the noise of a power grid signal through the “noise analysis” function in real-time, and analyze true synchrophasor measurement errors when the UGA is connected to the power grid. The noise analysis function of the UGA calculates the power spectral density (PSD) of a power grid signal. This function enables the evaluation of synchrophasor measurement errors in a real-power grid environment by generating an artificial signal with known parameters that has the same amount of noise as original power grid signal as shown in Fig. 3. Fig. 4 shows the synchrophasor measurement errors in a distribution power grid environment.
 L. Zhan, J. Zhao, J. Culiss, S. Gao, Y. Liu, et al., "Universal Grid Analyzer Design and Development", 2015 IEEE PES General Meeting, submitted.
 L. Zhan, Y. Liu, "Improved WLS-TF Algorithm for Dynamic Synchronized Angle and Frequency Estimation," in Proc. 2014 IEEE PES General Meeting, pp. 1-5.