Performance Comparison of Primary Side PFM and Secondary Side PWM for SS Wireless Power Transfer CC/CV Control Strategy

Inductive power transfer system with constant current and constant voltage outputs for battery charging based on double‐channel T‐circuit

“…The performance of the proposed approach has been compared with other methods (1) using control methods, (2) using particular frequency points, and (3) using compensation topologies, as outlined in Tables 3 and 4. Compared to the methods using control schemes [8,9,11], and [12], the proposed method can simplify the design of the control scheme. Compared to [13] and [15][16][17][18][19][20][21], the proposed method has better design flexibility in terms of the design freedom of charge current/voltage.…”

“…A lot of approaches have been investigated to realize CC-CV charging. Phase shift control [8] and variable frequency control [9] are common approaches, which can be employed to modulate the output current or voltage of the IPT system to realize CC-CV charging. But it is hard to guarantee zero phase angle (ZPA) for the inverter during the whole charging process.…”

“…Moreover, it is superior to other methods. Compared with the methods using control schemes [8][9][10][11][12], only simple feedback control is needed for DTLS. Compared with the methods selecting particular frequency points [13,14], the proposed DTLS can realize both CC-CV output and ZPA simultaneously for arbitrary MC structure.…”

Novel Control Approach for Resonant Class-DE Inverters Applied in Wireless Power Transfer Systems

“…To compare the proposed solution with other similar approaches available in the literature, let us present a brief discussion of traditional control methods applied in WPT while also considering Table 1. Pulse frequency modulation (PFM) is often employed on the primary side to obtain constant current and constant mode control [48]. However, if the switching frequency deviates too far from the resonant frequency, the switches may no longer achieve the soft-switching condition.…”

“…In turn, pulse width modulation (PWM) applied on the secondary side allows for overcoming such drawbacks. Thus, one can keep the switching frequency constant and close or equal to the resonance frequency to cancel the reactances associated with the leakage inductance and the compensation capacitance, yielding soft-switching operation and a higher efficiency [48]. Applying the Z transform to (9), one can obtain the discrete-time transfer function of the controller used by the class DE resonant inverter as in (10).…”