A power flow tracing method based on power electronic signaling for P2P electricity trading in DC microgrids

This paper proposes a novel power flow tracing method based on power electronic signaling (PES) for peer-to-peer (P2P) electricity trading in DC microgrids. It employs a superimposed low-frequency sinusoidal carrier to trace DC power flows according to the bus port impedance characteristics of power converters. In order to support fair and accurate P2P trading, source-to-load power signaling (S2LPS) and source-to-source power verification (S2SPV) methods are presented. Through S2LPS, the P2P DC power flow from a specific distributed source (DS) to a power load (PL) is determined by detecting the carrier’s active power at the PL’s bus port. The same carrier is used to check the actual output power of the DS by S2SPV. By implementing S2LPS and S2SPV, the power flows of the system are traced, recorded, and verified by each DS and PL. Accurate power flow tracing is achieved on the physical layer, providing reliable data for P2P electricity trading. The principles of the proposed method are deduced in detail. Furthermore, the modifications to the control loops of DSs and PLs are depicted for implementations in DC microgrids. Finally, a 2.5kW experimental platform is built to validate the correctness and feasibility of the proposed method.