This paper presents a power quality evaluation of the Class-D high-frequency power amplifier/inverter. The real, reactive, complex, apparent, distortion, and non-active powers at the input of the resonant circuit are derived and illustrated as functions of frequency. Also, the total harmonic distortion and power factor are determined. Similar analysis of the power quality at the dc input of the amplifier is given. Experimental results are given to verify the theory. It is shown that the input current of the Class-D inverter contains a significant ac component that does not contribute to the real dc input power, resulting in high distortion power, high total harmonic distortion, and poor power factor. The Class-D inverter was designed, built and tested to verify the theory.

In this paper, a comparison of different control strategies applied to a series-series (SS) compensated wireless power transfer (WPT) system is presented. The aim of the comparison is to find the most suitable strategy which is able to stabilize the system when misalignment conditions occur in the in-air coils of the converter, putting in evidence the main limitations of each tested control strategy. Some preliminary analyses in steady-state conditions are conducted to predict the possible limitations of the control strategies. The closed loop control strategies are designed using the control to output transfer functions of the system, which are used to tune the parameters of a proportional-integrative-derivative (PID) controller. The performances of the system controlled with the different control strategies are evaluated in Simulink environment.

Simultaneous wireless power and data transfer (SWPDT) is a technology that enables the transfer of electrical power and data signals at the same time. Since the transfer is performed through the same physical link, particular attention must be placed on the frequency response and mutual influence between data and power channels. Although several studies have been proposed for SWPDT modeling applied to electric vehicles (EV), an extensive analysis of the influence of misalignment on the frequency response of the data channels is lacking in the literature. This article investigates the robustness to misalignment of the data channel using two main resonant topologies, such as those based on series–series (SS) andLCC–LCCcompensation circuits. The analytical model of the data channel is derived for both topologies and the performances are evaluated in two lab prototypes using the misalignment scenarios described in the SAE J2954 standard. Variables, such as efficiency, signal-to-noise ratio (SNR), and capacity of the data channel have been analyzed. Similarly, attention has been paid to backward data transmission, which is of interest for vehicle-to-grid chargers. The obtained results in each analysis show that the data channel inLCC–LCCtopology has a more stable and symmetrical performance.

This paper presents an analysis of an LCR second-order low-pass filter capacitor to achieve a specified ripple output voltage in Buck, forward, Zeta, and Ćuk PWM DC-DC power converters for continuous-conduction mode (CCM). Current and voltage waveforms across output filter components are derived. Using the waveform of the ac component of the output voltage, an expression for the ripple voltage is developed in terms of the filter capacitance and equivalent series resistance. The results can be used for all PWM converters with the LCR output filter, such as Buck, forward, Zeta, and Ćuk PWM DC-DC converters. Theoretical results were in good agreement with simulation and experimental results.

In this paper, an LCC-S compensated wireless power transfer system regulated by a variable inductor is presented. The inductance variation is performed by exploiting the magnetic material saturation of the inductor core, regulating the DC bias. The magnetic design of the controlled variable inductor is proposed. A low-cost auxiliary circuit for the regulation of the bias current is proposed, and the performance is evaluated. The effect of the inductance variation on the output power regulation and conversion efficiency are evaluated through an experimental setup.

A model-based strategy for an efficient power supply control used in a wireless sensor network is presented. The strategy, based on Pulse-Skipping Modulation, regulates the current charging a battery, delivered by a photovoltaic source, resulting in an accurate current regulation and highly efficient power management. The strategy is implemented on a microcontroller unit and compensates for the microcontroller self-absorbed current. The modulation signal is generated through a full software interface, reducing the requirement for external components. Experimental validations, performed on a charger prototype by using a laboratory photovoltaic device simulator, proved that both regulation accuracy, regulation resolution and converter efficiency achieved are superior to the classic Pulse-Width Modulation. The approach results in a simple practical implementation, carries over the advantages of an up-to-date model for the photovoltaic device, and serves the auxiliary purpose of using the photovoltaic source as an instantaneous solar irradiance sensor.

A Wireless Power Transfer System (WPTS) is basically constituted by two main parts: the primary side and the secondary side. Beyond the application related with the power transfer, also data communication between these two sides can be implemented and it can have a fundamental importance. In this paper, a classification that highlights the advantages and the disadvantages of different data communication techniques available in the literature is shown. The single link dual carrier (SLDC) technique is studied in depth, analysing transfer function of the power and data transmitting channels. A design example for electric vehicle wireless charging application in a Series-Series (SS) compensated system is presented. The analytical models are validated through simulations.

This paper presents a novel means of controlling a dynamic power supply in continuous conduction mode via sliding-mode voltage control technique. Previous work has discussed the design and implementation of a high-efficiency dynamic power supply based on an asynchronous buck converter in open-loop operation. This work incorporates nonlinear control design for the dynamic buck converter that suits applications such as envelope tracking and amplitude modulation for Class E power amplifiers. The control system is shown, via MATLAB simulation, to accurately track time-varying reference signals, improve the power converter dynamics, and provide the desired output power while rejecting large load disturbances.

LLC resonant converters offer high efficiency at high frequencies because of their ability to achieve Zero Voltage Switching (ZVS) or Zero Current Switching (ZCS). However, they require a variable frequency control, which generates a wide range of harmonics and causes electromagnetic compatibility issues. The frequency control reduces the converter efficiency at lighter loads and fails to maintain monotonicity of the control power to output transfer function. These limitations are dramatically improved by phase shift modulation (PSM) technique, which is studied in this paper. PSM controlled technique in full-bridge converter, not only improve the monotonicity of the power supply control to output transfer function, but also improves the power supply efficiency at light loads. A systematic analysis and characteristics of a PSM LLC resonant converter is proposed in this paper along with a comparison with conventional frequency modulated (FM) controlled LLC converter. The simulated PSM controlled LLC topology exhibited a maximum peak efficiency of 97.47%. At lighter load conditions, it records an efficiency of 91.66% while the FM controlled converter recorded only 82.8 %. In addition, PSM has a better control of leakage, magnetizing, and resonant currents, which results in a superior behavior than conventional FM converters.

In this paper, a nonlinear approach to modeling DC-DC PWM converters in continuous conduction mode (CCM) is presented. Specifically, a converter nonlinear model is implemented in MATLAB and SIMULINK for both the case without parasitic components (ideal case) and with parasitic components (non-ideal case). The implementation, which is based on the analytical computation of the periodic solutions in the high frequency steady-state operating condition, makes it possible to perform a systematic analysis of the dynamical behavior induced by the various perturbation sources acting on the converters. A comparison of the dynamics generated in the ideal and nonideal cases by step changes in duty cycle, input voltage and load resistance is reported for both the boost and buck converters.

DC-DC pulse-width modulated (PWM) converters are nonlinear systems that require control circuits to obtain the desired output voltage. These control circuits are often designed using linearized models of the converters, so modeling is a relevant topic for the design of performing closed-loop converters. In this paper, the nonlinear nature of DC-DC PWM converters operated under continuous conduction mode (CCM) is considered. It is first shown how the exact periodic solutions can be analytically computed for the nonlinear converter model in the high-frequency steady-state operating condition. Also, a nonlinear variation model, which characterizes the closed-loop dynamics, induced by perturbations of the steady state, is provided. The nonlinear models and the analytical periodic solutions are implemented in MATLAB and SIMULINK and applied to a boost converter subject to parasitic components. In particular, the behavior to step changes in duty cycle, input voltage, and load resistance are compared with the results obtained using small-signal circuit averaging techniques.

This paper presents a completely new technique developed to locate a single parametric fault in DC-DC power converters by means of time-domain measurements or simulations, following a rigorous approach. The technique is composed by three separated stages, a first one which evaluates testability and ambiguity groups of the Converter (or, more in general, the Circuit) Under Test (CUT), a second one which localizes the fault, classifying it in an appropriate Fault Class (FC) and a last one (optional) that can extract the value of the faulty component. The fabrication tolerances of the healthy components are taken into account at each stage of the method.

The design of Class-E zero-voltage switching (ZVS) inverter with a loosely-coupled transformer is introduced in this paper. In the presented approach, the magnetizing and leakage inductances of the transformer are absorbed into the main circuit. The synthesis of the transformer-version of Class-E ZVS inverter into its equivalent π2a topology is presented. The π2a topology improves the range of the optimum load resistance required to achieve ZVS. An example of the Class-E inverter with dc supply voltage 10 V, output power 10 W, switching frequency 100 kHz and at a coupling coefficient of 0.77 is considered. The inverter is designed to achieve both zero-voltage switching (ZVS) and zero derivative switching (ZDS) conditions. The analytical expressions are validated through simulation results for an optimum coupling coefficient of 0.77. In view of potential misalignment between the primary and secondary coils, simulation results are provided for coupling coefficients, which are lower and higher than the optimum value. It is shown that both ZVS and ZDS can be achieved at a coupling coefficient lower than the optimum value and is not possible to achieve ZVS at a coupling coefficient higher than the optimum value. Overall efficiency of 94.3% is achieved at a coupling coefficient of 0.77, 93.4% at 0.85, and 92.12% at 0.7. The presented approach can be used for transformers with reactive load impedances also.