Embedding power line communication in photovoltaic optimizer by modulating data in power control loop
journal contributionposted on 27.06.2019, 10:09 authored by Yue Zhu, Jiande Wu, Ruichi Wang, Zhengyu LinZhengyu Lin, Xiangning He
In a photovoltaic system, a dc-dc power optimizer (DCPO) is an option to maximize the output power. At the same time, data links among DCPOs are often required for system monitoring and controlling. This paper proposes a novel power line communication method for the DCPOs, in which the data of a DCPO are modulated into the control loop of a power converter, and then transmitted through the series-connected dc power line to other DCPOs. In the process of communication, differential phase-shift keying modulation and discrete Fourier transformation demodulation are employed. To analyze the quality of communication, the communication model of the system is built, based on a small-signal model. Furthermore, the noises of the system, including switching, maximum power point tracking, and additive white Gaussian noise, are discussed and measured to evaluate the signal-to-noise ratio. Lastly, an experimental system including six DCPOs is established and tested, which verifies the feasibility and effectiveness of the proposed method.
National Nature Science Foundation of China under Grant 51577170, in part by the National Key Technologies R&D Program of China under Grant 2017YFE0112400, and in part by the European Union’s Horizon 2020 research and innovation programme under Grant 734796.
- Mechanical, Electrical and Manufacturing Engineering