Series and parallel capacitor compensation of the transmitter in a magnetic resonance based motoring system

Resonant wireless power transfer has been developed and employed for transferring power to electrical loads. In recent research, the induced currents were directly used to exert forces or torques on a movable resonator coil. A high variability is present in the torque profile of a resonance based motoring system. In wireless power transfer, multiple compensation methodologies exist to counteract the reflected impedance of the load and to optimize the power flow, efficiency and/or VA rating of the source. This paper investigates the effect of the capacitor tuning for the two most common compensation methods in wireless power transfer, namely series LC and parallel LCL compensation. As a result of the highly variable reflected impedance, the peak torque does not always coincide with the zero phase angle of the total load impedance or the transmitter current peak. The torque generation capability, namely the ratio of average torque to maximum current, of both methods is largely similar. The LCL method has a higher peak value, which does however not coincide with its efficiency peak, so a trade-off is required. The efficiency of the LCL topology is shown to be significantly larger than the series LC transmitter.

ISBN:9781728148786

Publication year:2019

Accessibility:Closed