Variable Zero-Vector-Width-Based Three-Phase DC/AC Talkative Power Conversion

Talkative power conversion (TPC), which embeds information into the switching ripples of power converters to achieve the simultaneous transmission of power and data without installation of additional hardware, can reduce the additional communication infrastructure in cyber-physical systems of digital energy and modern power plants. TPC in DC/DC converters has been the subject of numerous investigations, but comparatively few studies have focused on DC/AC converters. In this paper, a novel variable zero-vector-width modulation (VZVWM) for three-phase DC/AC converters is proposed to achieve TPC. The DC/AC converters can transmit information to the receiver, crossing the LCL filter and power cable, with a good power quality. The harmonic distribution is mathematically analyzed, underpinning the viability of VZVWM-based TPC, and leading to the proposed sliding FFT-based demodulation. The EMI performance of the VZVWM-based talkative DC/AC converter is studied in detail. The correctness of harmonics distribution and feasibility of the VZVWM-based TPC is validated in simulations and experiments. Total harmonic distortion and bit error rate are evaluated with regard to variable cable distances, types, and zero vector’s widths.