Extrapolation-based Real-time Phasor Data Compression Considering the Two-way Rotation Characteristics of Synchrophasors

To deal with the time delay caused by data compressions for synchrophasors in phasor measurement units (PMUs), an extrapolation-based real-time phasor data compression (ER-PDC) was proposed in this paper. First, the two-way rotation characteristic of synchrophasors was analyzed to enhance the real-time extrapolation of phasor dynamic tracks. Then, the algorithm of phasor data compression and reconstruction was proposed with an accuracy criterion measured by the total vector error (TVE) of phasors. The actual PMU data measured in a low-frequency oscillation incident were used to verify the compression performance of ERPDC, and ERPDC was compared with a phasor swing door trending (PSDT) data compression technique. Enhanced by the extrapolation of the synchrophasor dynamic tracks, the comparative result demonstrates that ERPDC can achieve the real-time data compression with zero delay at the expense of slightly decreased compression ratios.

I. Introduction

Based on the rapid development and broad application of synchrophasor measurement technology and wide-area measurement systems (WAMS), an increasing number of Phasor Measurement Units (PMU) are installed in the power systems, especially in distribution networks. As a consequence, the large amount of synchrophasor data will cause the low efficiency of communication bandwidth and insufficient storage space. In order to transmit synchrophasor measurement data in power systems better, data compression is required to reduce the amount of synchrophasor measurement data.