Energy harvesting in electric power systems

Abstract

This dissertation investigates the energy harvesting (EH)in electric power systems and itsusefulness to power hybrid data communication systems, based on the combination of powerline communication (PLC) and wireless communication (WLC)ones. In this context, generalaspects of EH in electric power systems are discussed,highlighting the advantages and drawbacksof harvesting energy based on typical classifications of theelectric power systems in terms ofvoltage levels and on the frequency bands of the spectrum content of electric signals. First,the harvested energy is quantitatively evaluated in the concatenated configuration of broadbandPLC and WLC channels, in the parallel combination of narrowband PLC and WLC channels,and in the main harmonic components of electric signals. Second, the use of the harvestedenergy for data communication purposes is evaluated in terms of ergodic achievable data ratesof these channels, and the number of transceivers powered bythis energy is estimated for fivedata communication standards commonly adopted by low-power data communication devices.Based on an in-home measured data set, numerical analyses showed that the energy harvestedfrom the disturbances in electric signals on the frequency band delimited by the broadband PLCtechnology is a remarkable part of the amount of the total harvested energy. Also, EH-based datacommunications attained ergodic achievable data rates from dozens of bps or kbps to dozens ofMbps, depending on the use of narrowband or broadband channels. Moreover, this dissertationaddresses a novel mathematical formulation to precisely quantify the EH from wasted power inelectric signals and extends this formulation to the harvested power. In this context, it shows thatthe wasted energy dynamic of the main harmonic components ofelectric signals in a buildingfacility can be considered cyclostationary and stationaryrandom processes on the weekdaysand weekends, respectively. As well, it estimates that millions, or even billions, of transceiverscan be powered by means of the harvested power from disturbances in electric signals of theBrazilian electric power systems and, at the same time, positive impacts are expected in thepower quality of these systems. Finally, the energy of disturbances in electric signals on thefrequency band of any PLC technology has tremendous potential for feeding up low-power datacommunication devices such as the ones in the Internet of Things, smart grids, and Industry 4.0.