Talkative Power Conversion based on Direct Sequence Spread Spectrum in AC Power Systems

The high-penetration integration of renewable energy generation, energy storage systems, and diversified loads are driving the evolution of distribution grids into cyber-physical systems. Advanced communication, serving as the essential infrastructure of modern power system, plays a pivotal role in the awareness, measurement, dispatching and control of the system, especially the coordination among multiple resources. Talkative power conversion (TPC) technology leverages the high-speed modulation capabilities of power electronic converters (PECs) to achieve hardware-free communication through software-defined communication systems (SDCS). However, the inherent characteristics of AC power lines – including resonant behavior and attenuation properties – introduce complexities in TPC implementation, and also compromise communication reliability and data integrity. Additionally, the superposition of data carriers on power waveforms raises electromagnetic interference (EMI) and information security concerns. To address these challenges, this paper proposes a direct sequence spread spectrum (DSSS) based modulation strategy for AC-TPC systems. This method employs optimized DSSS parameters to upshift data carriers to higher frequency bands, maintaining communication reliability while minimizing harmonic distortion and voltage distortion. In addition, this proposed approach supports a multi-user access mechanism in AC microgrids and improves the communication rate by exploiting redundant pseudo-noise (PN) sequence. Experimental results demonstrate that the proposed strategy achieves stable, secure, and multi-user communication while maintaining power quality requirements, providing a novel solution for future applications in microgrid coordination and control, emergency communications, and critical signal transmission. Moreover, the proposed communication scheme is entirely based on SDCS, with virtually zero deployment cost.