In wireless charging devices, different wireless charging standards have caused charging incompatibility, and the utilization rate of the DC voltage at the transmitter is not high, which brings challenges to the application of wireless charging. To solve these two problems, this paper proposes a multi-frequency multi-amplitude (MFMA) superimposition modulation method. This method superimposes multiple frequency signals, and then compares the synthesized signal with a high-frequency triangular carrier to output a square wave voltage signal containing information such as the frequency and amplitude of the pre-output signal. Furthermore, a phase-shifting optimization algorithm is proposed, i.e., based on the proposed MFMA superimposition modulation method, the utilization rate of the DC voltage of the system is improved by reasonably adjusting the initial phase of each frequency. Simulation and experimental results show that the proposed method can output at least four frequencies simultaneously by using a single inverter, effectively reducing the volume of the transmitter, and being compatible with the frequency range of several charging standards. The proposed phase-shifting optimization has a significant effect on improving the utilization of DC voltage with an increase of 44.88%.

In wireless power transfer (WPT) system, communication between the primary and the secondary plays an important role in system status monitoring and operation control. Bidirectional information transmission is also essential to detect the working state and send control command in both sides. This paper proposes a bidirectional simultaneous wireless information and power transfer method. The secondary has a simple structure and employs only one switch. The proposed WPT system can achieve bidirectional information transmission via a sharing inductive link. The forward information is transferred by using a single full bridge inverter based on selected harmonic elimination PWM (SHEPWM) control methods without other high-frequency signal sources. In the secondary side, uncontrolled rectifier and a parallel MOSFET are adopted to realize constant voltage output and backward information transfer. The backward information modulation is achieved by changing the switching frequency of MOSFET. The forward and backward information demodulation modules are designed and analyzed in details. A 30W experiment platform with forward communication rate 5 kbps and backward communication rate 10 kbps is built to verify this proposed method.

Communication between the primary and secondary sides is pivotal to the wireless power transfer (WPT) system. The system control commands and feedback information need simultaneous wireless information and power transfer (SWIPT). In this paper, a FSK-based SWIPT system with full-duplex communication via a shared channel is provided. Considering the complexity of the coupling relationship in this kind of full-duplex SWIPT system, this paper proposes an analysis method based on the transmission channel, studies the crosstalk between the power channel and the information channel, and between the forward and reverse transfer of information. A design method of full-duplex communication SWIPT system based on shared coupling channels is provided. A 60 W SWIPT prototype with a full-duplex communication rate of 20 kbps is built to verify the proposed method.

To make a trade-off between computation burden and control performance of the existing robust MPC algorithms, this paper proposed an improved robust MPC strategy considering one degree-of-freedom for control variable(s), which makes a trade-off between computation burden and control performance. Firstly, based on RBF-ARX (state-dependent Auto-Regressive model with eXogenous input and Radial Basis Function network type coefficients) model, a polytopic uncertain linear parameter varying (LPV) model can be built, and two convex polytopic sets can be constructed to wrap the globally nonlinear behavior of the system. Then, a quasi-min-max MPC problem was formulated as a complex linear matrix inequalities (LMIs) optimization problem, which can be solved through a fast computation strategy that contains an online algorithm and an offline algorithm. To reduce its conservatism, this paper introduced one free variable(s) to control variable(s) and designed a new online algorithm, which means that a simple online optimization problem was formulated to solve for the introduced free variable(s). During online control process, the new algorithm only needs to execute simple state-vector computation and bisection search, and then solves a simple LMI optimization problem to obtain free variable(s). In addition, the stability of the closed-loop system was studied. Finally, two examples, i.e. a widely used continuously stirred tank reactor and a linear one-stage inverted pendulum, are provided to test the effectiveness of the proposed RBF-ARX model-based efficient robust predictive control approach with one degree-of-freedom for control variable(s).

This article presents an integrated double-sided inductance and double capacitances (DS-LCC) compensation based dual-frequency compatible wireless power transfer (WPT) system. A cascaded single-phase multi-frequency inverter (CSMI) is constructed to generate the independent dual-frequency power transfer signals. In order to achieve the load-independent constant-current output (CCO) at two frequencies, an integrated DS-LCC compensated topology is reconstructed. By configuring the frequency-selective resonating compensation (FSRC) network in the primary side, the power transfer signals at two frequencies can be superimposed into a single transmitting coil, reducing the cost and volume of the system. Furthermore, to implement zero-voltage switching (ZVS) of the CSMI throughout the entire power range, a general parameter design method of the proposed system is also introduced. A 1.5-kW experimental prototype is built to validate the practicability of the presented dual-frequency compatible WPT System. The system can supply power to different loads at two frequencies simultaneously with CCO and ZVS properties. The peak efficiency reaches 91.75% at a 1.2-kW output power.