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This paper presents a discrete sliding mode control (DSMC) scheme for a series–series compensated wireless power transfer (WPT) system to achieve fast maximum energy efficiency (MEE) tracking and output voltage regulation. The power transmitter of the adopted WPT system comprises a dc/ac converter, which incorporates the hill-climbing-search-based phase angle control in achieving minimum input current injection from its dc source, thereby attaining minimum input power operation. The power receiver comprises a buck–boost converter that emulates an optimal load value, following the MEE point determined by the DSMC scheme. With this WPT system, no direct communication means is required between the transmitter and the receiver. Therefore, the implementation cost of this system is potentially lower and annoying communication delays, which deteriorate control performance, are absent. Both the simulation and experiment results show that this WPT system displays better dynamic regulation of the output voltage during MEE tracking when it is controlled by DSMC, as compared to that controlled by the conventional discrete proportional-integral (PI) control. Such an improvement prevents the load from sustaining undesirable overshoot/undershoot during transient states. [ABSTRACT FROM PUBLISHER]

This paper proposes a phase-shift interleaving control method for variable-phase switched-capacitor (SC) converters that can perform voltage conversions with little electromagnetic interference over a wide range of operating condition. This is achieved by having multiple units of SC converter connected in parallel and an N-state hysteresis unit selection control scheme which works along the interleaving control to vary the number of converters in operation. By having the capacitors of inactive units connected to the output and the converters operating with output interleaving operation, the output capacitor that is typically required in SC converters for maintaining a small voltage ripple is made redundant in this configuration. A three-unit SC converter of the proposed configuration is described in this paper. Experimental results show that the proposed solution works satisfactorily with good regulation, input and output interleaving operations, and dynamic response for a wide operating range. [ABSTRACT FROM PUBLISHER]

The switched-capacitor (SC) converters are ideal switching-mode power supplies for consumer portable electronic devices due to their nature of being light weight, small size, and high-power density. However, they suffer from a discontinuous input-current waveform with large di/dt, which leads to significant electromagnetic interference emission. This paper proposes a configuration of SC converters connected in parallel, with their inputs and outputs interleaved and adaptively controlled. The interleaving operation is performed by using an original type of control in which both the capacitors’ charging time TON and switching frequency are adjusted to get the line and load regulation. It is shown that, for a given range of variation of the supply voltage and load, there always exists a solution [TON, TS] that assures both output-voltage regulation and perfect interleaving. Experimental results are provided to validate the feasibility of the proposed scheme. Precise interleaving, and good line and load regulation are maintained for all the designated range, including the transient periods. [ABSTRACT FROM PUBLISHER]