A Weather-Independent and Renewable Power Supply With Wireless Power Transfer Feature for Powering Online Monitoring Systems in Smart Grid
Jiali Zhou, Zilin Li, Chi-Kwan Lee, Ka Wing Chan, S.Y.R. Hui
Abstract
The merge of the power and information infrastructures in the smart grid requires an increasing number of sensors and online monitoring systems on the high-voltage transmission towers. These systems are traditionally powered by small solar panels or wind turbines that are weather-dependent. This new contribution involves a full analysis of a complete weather-independent power supply to replace existing approaches. For the first time, the complete system comprising the energy harvesting, wireless power transfer (WPT) and output power stages are practically evaluated using printed circuit board (PCB) resonators embedded in a 35-kV composite insulator. We leverage the nearly constant current, transresistance, and voltage gains characteristics of the PCB domino-resonator structure under different self-oscillating frequencies and propose a coordinated control scheme of transmitter-side and receiver-side converters to regulate the constant current (CC) or constant voltage (CV) through the entire charging process. Any current surge caused by the burst operation of the active rectifier on the receiver side triggers a transition between different self-oscillating operations on the transmitter side, leading to operating region extension of the active rectifier. Thus, the proposed system can easily adjust the output to follow different battery charging profiles without wireless communication between the transmitter and receiver.