Data Compression for Differential Protection of Distribution Network: A Wavelet Approach

With the ever-increasing integration of high proportions of renewable energy sources, the distribution network is gradually becoming a multi-source grid. Differential protection could remove the fault line from both sides and has good protective performance in transmission network. However, differential protection has a high requirement for time delay and communication capacity, making it difficult to be applied to distribution networks. This paper analyzes the data compression requirements of differential protection in distribution network and presents a data compression scheme based on the discrete wavelet transform (DWT) for differential protection. To verify the effectiveness, a 10kV distribution network simulation model was established in PSCAD/EMTDC. The data demonstrates the feasibility of the DWT-based data compression algorithm for differential protection. Finally, this paper discusses the selection of wavelet decomposition level and wavelet function and their influence on data compression performance.