Extending the Operating Region of Inductive Power Transfer Systems Through Dual-Side Cooperative Control

Modeling, design, and control of inductive power transfer systems

“…Pulse density modulation (PDM) is another modulation scheme suitable for IPT. The core principle of PDM is to modulate conventional PWM signals as shown in Figure 2.23, to determine the ON and OFF instants of switching devices at the base of a half [56,57,72] or an entire period [73][74][75][76]. Consequently, uin is affected that uin is '0' at every '0', while 'P' and 'N' respectively refer to the normal positive and negative outputs.…”

“…Delta-sigma modulation [55][56][57] is another approach that can be rapid responding and with low-subharmonic. However, even with novel PDM patterns, system variations could still persist, such as an envelope on current [75]. Besides, the subharmonic in PDM could potentially aggravate the EMI issue.…”

“…This modulation is summarized from several works [72,75,[77][78][79][80] where one famous representative is ON-OFF keying modulation [78]. The burst mode modulation is similar with PDM, considering that the main principle of both is to keep switching devices always ON/OFF for a while.…”

“…The burst mode modulation is similar with PDM, considering that the main principle of both is to keep switching devices always ON/OFF for a while. However, different from PDM where '1's and '0's are fast alternating, the ON/OFF time duration in burst mode modulation is intentionally designed to be long, e.g., several milliseconds while one switching period is 10 microsecond [75]. From Figure 2.28, existing burst mode modulation approaches can contain two or all of the three modes: the full-bridge (FB) mode, the half-bridge (HB) mode, and the short circuit (SC) mode.…”

“…One advantage of burst mode modulation is the easy implementation, i.e., almost no additional hardware or software requirement. Moreover, burst mode modulation can be simultaneously applied with other modulation methods [75] or control [77], which indicates high flexibility. Nonetheless, one drawback of burst mode modulation is that the SC mode can lead to enlarged output ripples.…”