Power Yield of a Constant Voltage Load Feeding Magnetic Energy Harvester Equipped With Series Constant-Valued AC Capacitor

The letter focuses on clamped-type passive magnetic energy harvester equipped with constant-valued series AC-side capacitor (cCs-MEH), supplying power to a constant voltage load (CVL) representing a battery or regulated DC bus, via diode bridge rectifier (DBR). Such an arrangement may serve as e.g. powertrain of a platform for uninhabited aerial electrical vehicle batteries charging residing in the vicinity of overhead power lines. It was recently shown that series-connected capacitor addition allows to enlarge the harvested power by up to 27% due to decoupling of the load from the voltage applied to transformer core. However, the capacitance value must be adjustable to allow maximum harvested power increase under arbitrary primary current magnitudes, significantly complicating the system and reducing reliability. On the other hand, equipping the MEH with a constant-valued series capacitance seems to be more practical. Yet, harvested power boost is expected to be lower than the above-mentioned amount. This brief aims to bridge the gap by discussing sizing process of series capacitance value and assessing the power harvesting potential of a cCs-MEH driving a CVL within certain range of primary current magnitudes. Such an investigation has not been reported in the literature so far. In addition, it is revealed that a cCs-MEH would be outperformed by an optimally designed series capacitorless MEH (utilizing the same core) under low primary currents. Experimental results of a cCs-MEH clamped on conductor carrying 50A – 350A, 50Hz currents are provided to validate the findings.