Accurate first-harmonic-approximation-based model of the diode rectifier in series-series compensated inductive wireless power transfer link at load-independent-voltage-output frequency

Quadrature Demodulator-Assisted Estimation of Load Voltage and Resistance Based on Primary-Side Information of a Wireless Power Transfer Link

“…In DCM, the linear relation between the AC and DC side variables of the secondary no longer holds. As shown in [27], the imaginary part of the diode rectifier input impedance (possessing inductive characteristics [29] yet susceptible to neglect in CCM) rises significantly in DCM. Moreover, the primary and secondary currents contain significant harmonic content and the first harmonic approximation becomes inaccurate.…”

“…The measured static output voltage versus load power curve was derived in [27] and is reproduced in Figure 7. According to (29) and (31), there is…”

“…By utilizing QDs, the accuracy of the phasor-domain solutions subgroup is greatly improved. In order to demonstrate the enhanced algorithm performance, it is applied to a series-series compensated inductive WPT link operating at a load-independent-voltage-output frequency [28,29]. Such an operation is suitable for systems operating with a constant and known coupling coefficient [30,31], yielding a DC voltage output that is nearly unaffected by the load.…”

Output Voltage and Resistance Assessment of Load-Independent-Voltage-Output Frequency Operating Inductive Wireless Power Transfer Link Utilizing Input DC-Side Measurements Only

“…For SS-compensated IWPT links, two operating frequencies were shown to yield loadindependent voltage output, one residing below (capacitive region) and the other above (inductive region) resonant frequency [14,15], both being coupling coefficient dependent. In case the latter is constant and known (such as in case of wireless power delivery system into enclosed compartment, where transmitting and receiving coils reside statically on two sides of the compartment walls [12,16,17]), load-independent voltage output (LIVO) may be ideally achieved at the design stage, and the system may potentially be feedback-free [12]. In practice, LIVO operation is impossible due to primary and secondary nonzero parasiticresistances and invalidity of the phasor-domain equivalent circuit under light loading.…”