Slipstream: High-Performance Lossless Compression for Streaming Synchronized Waveform Monitoring Data

Abstract

Fundamental changes in power grids due to decarbonization require advanced monitoring and automated analysis. Capturing synchronized waveform data from voltage and current sensors, sometimes referred to Continuous Point on Wave (CPOW) monitoring, offers several capabilities beyond synchrophasors from Phasor Measurement Units (PMUs). However, the obvious drawbacks in manipulating, transferring, and storing waveform are the high data bandwidth and storage requirements. Therefore, access to streaming synchronized waveform data is typically restricted to substation local area networks (LANs). This paper reports on a platform to address these issues and therefore to deliver wide-area waveform monitoring in a way which is convenient and practical. It is shown how a lossless data compression method designed for streaming waveform data can significantly reduce data bandwidth requirements and improve end-to-end efficiency and latency. Data bandwidth requirements can be reduced to 5-15% of the original size. The same approach can be applied to both real-time streaming and offline data storage, with reduced file size compared to other industry formats such as COMTRADE and PQDIF. It supports any sampling rate, any number of samples per message, and arbitrary configurations of measurement quantities to be sent. An implementation of the scheme, called Slipstream, has been open sourced to enable industry adoption.