The major consideration in dc-dc conversion is often associated with high efficiency, reduced stresses involving semiconductors, low cost, simplicity and robustness of the involved topologies. In the last few years, high-step-up non-isolated dc-dc converters have become quite popular because of its wide applicability, especially considering that dc-ac converters must be typically supplied with high dc voltages. The conventional non-isolated boost converter is the most popular topology for this purpose, although the conversion efficiency is limited at high duty cycle values. In order to overcome such limitation and improve the conversion ratio, derived topologies can be found in numerous publications as possible solutions for the aforementioned applications. Within this context, this work intends to classify and review some of the most important non-isolated boost-based dc-dc converters. While many structures exist, they can be basically classified as converters with and without wide conversion ratio. Some of the main advantages and drawbacks regarding the existing approaches are also discussed. Finally, a proper comparison is established among the most significant converters regarding the voltage stress across the semiconductor elements, number of components and static gain.

https://ietresearch.onlinelibrary.wiley.com/doi/pdf/10.1049/iet-pel.2014.0605

Survey on non-isolated high-voltage step-up dc–dc topologies based on the boost converter

Multiphase converter topologies for use in high-performance applications have received increasing interest in recent years. This paper proposes a novel multidevice interleaved boost converter (MDIBC) that interfaces the fuel cell with the powertrain of hybrid electric vehicles. In this research, a multidevice structure with interleaved control is proposed to reduce the input current ripples, the output voltage ripples, and the size of passive components with high efficiency compared with the other topologies. In addition, low EMI and low stress in the switches are expected. The proposed dc/dc converter is compared to other converter topologies such as conventional boost converter (BC), multidevice boost converter (MDBC), and two-phase interleaved boost converter (IBC) to verify its dynamic performance. Furthermore, a generalized small-signal model is derived for these dc/dc converters, which has not been previously discussed. A digital dual-loop control is designed to achieve the proper regulator for the converters with fast transient response. The dc/dc converter topologies and their controller are designed and investigated by using MATLAB/Simulink. Finally, the proposed converter (MDIBC) is experimentally validated with results obtained from a 30-kW prototype that has been built and tested in our laboratory based on TMS320F2808 DSP. The simulation and experimental results have demonstrated that the proposed converter is more efficient than other dc/dc converter topologies in achieving high performance and reliability for high-power dc/dc converters.

Analysis, Modeling, and Implementation of a Multidevice Interleaved DC/DC Converter for Fuel Cell Hybrid Electric Vehicles

By utilizing a memristor to substitute a coupling resistor in the realization circuit of a three-dimensional chaotic system having one saddle and two stable node-foci, a novel memristive hyperchaotic system with coexisting infinitely many hidden attractors is presented. The memristive system does not display any equilibrium, but can exhibit hyperchaotic, chaotic, and periodic dynamics as well as transient hyperchaos. In particular, the phenomenon of extreme multistability with hidden oscillation is revealed and the coexistence of infinitely many hidden attractors is observed. The results illustrate that the long term dynamical behavior closely depends on the memristor initial condition thus leading to the emergence of hidden extreme multistability in the memristive hyperchaotic system. Additionally, hardware experiments and PSIM circuit simulations are performed to verify numerical simulations.

Hidden extreme multistability in memristive hyperchaotic system

In this paper, a simple novel control strategy is designed and analyzed for a hybrid energy storage system (HESS). In the proposed method, batteries are used to balance the slow changing power surges, whereas supercapacitors (SC) are used to balance the fast changing power surges. The main advantage of the proposed control strategy is that, the slow response of battery system including dynamics of battery, controller, and converter operation, is overcome by diverting the power surges to the SC system. The proposed method inherits charge/discharge rate control to improve the life span and reduce the current stresses on battery. The proposed method features less computational burden as it uses simple control strategy. The detailed experimental results presented validate the proposed control strategy for sudden changes in photovoltaic (PV) generation and load demand.

Design and Analysis of Novel Control Strategy for Battery and Supercapacitor Storage System

In this paper, a variable perturbation size adaptive perturb and observe (P&O) maximum power point tracking (MPPT) algorithm is proposed to track the maximum power under sudden changes in irradiance. The proposed method consists of three algorithms, namely current perturbation algorithm (CPA), adaptive control algorithm (ACA), and variable perturbation algorithm (VPA). CPA always tries to operate the photovoltaic (PV) panel at maximum power point (MPP). ACA sets the operating point closer to MPP, only if the operating limits are violated. These operating limits are expressed in terms of the operating current range of the PV panel and the sudden changes in irradiance. VPA dynamically reduces the perturbation size based on polarity of change in power. Two-stage variable size perturbation is proposed in this paper. The proposed algorithm is realized using a boost converter. The effectiveness of proposed algorithm in terms of dynamic performance and improved stability is validated by detailed simulation and experimental studies.

Variable Perturbation Size Adaptive P&O MPPT Algorithm for Sudden Changes in Irradiance

A simple memristor-based chaotic circuit with an active flux-controlled memristor characterized by a smooth continuous cubic nonlinearity is designed. The proposed chaotic circuit can generate a 2-scroll chaotic attractor on a finite time scale and has an equilibrium set with its stability dependent on the initial state of the memristor. The complex dynamics of the proposed chaotic circuit under different initial state of the memristor are investigated both theoretically and numerically. In particular, some novel transient transition behaviors with different time scales are found in the memristor circuit. Experimental observations based on a universal circuit implementation platform are conducted to partially verify the numerical simulation results.

A simple memristor chaotic circuit with complex dynamics

The output characteristics of a single-phase inverter with voltage and current dual closed-loop feedback control are analyzed, and the equivalent circuit model of a parallel single-phase inverter system is introduced. By taking both resistance and inductance components of the equivalent output impedance into consideration, a current decoupling control strategy of the parallel inverter system is then proposed. Furthermore, by constructing a three-phase balanced current according to the output current of the single-phase inverter, an active and reactive current decomposition method is presented to decompose the output current of the single-phase inverter into active and reactive currents according to the instantaneous reactive power theory. The block diagram of the active and reactive current decomposition method is given, and current decomposition simulation results are shown to verify the analysis results. The prototype is developed, and the control of two parallel-connected 2-kVA inverters is realized. The experimental results show its feasibility and effectiveness.

A Current Decoupling Parallel Control Strategy of Single-Phase Inverter With Voltage and Current Dual Closed-Loop Feedback

A novel pseudo-continuous conduction mode (PCCM) boost power-factor-correction (PFC) converter and its corresponding control strategy are proposed in this paper. Connecting a power switch in parallel with the inductor makes the boost converter operate in PCCM, which provides an additional degree of control freedom to realize PFC control. Therefore, a simple and fast voltage control loop of the PCCM boost PFC converter can be designed to realize output-voltage regulation. The additional degree of control freedom introduced by inductor current freewheeling operation of the PCCM boost PFC converter has been exploited through the dead-zone control technique, which can be dynamically adjusted in accordance with the output-voltage ripple. Compared with continuous conduction mode (CCM) boost PFC converter, the controller of the proposed PCCM boost PFC converter is much simpler. Moreover, the PCCM boost PFC converter benefits with reduced inductor-current ripple and improved power factor compared with boost PFC converter operating in discontinuous conduction mode (DCM). Analysis, simulation, and a 400-W prototype of the PCCM boost PFC converter have been presented and compared with those of boost PFC converters operating in conventional CCM and DCM. The results show that the dynamic response of the PCCM boost PFC converter is significantly faster than the existing boost PFC converter.

A Novel PCCM Boost PFC Converter With Fast Dynamic Response

A single-inductor dual-output (SIDO) buck–boost power factor correction (PFC) converter operating in critical conduction mode is proposed in this paper. By multiplexing a single inductor, each output of the SIDO buck–boost converter can be regulated independently. Compared with a conventional two-stage multiple-output converter, the SIDO buck–boost PFC converter benefits from significant overall cost saving, small size, and light weight. Moreover, the efficiency of the SIDO buck–boost PFC converter can be improved due to single-stage power conversion. The control strategy and characteristics of the proposed converter are analyzed. The efficiency, power factor, total harmonic distortion, and output accuracy are verified using the experimental results.

Single-Inductor Dual-Output Buck–Boost Power Factor Correction Converter

A unified averaging technique, here called the generalized state-space averaging (GSSA) technique, for the analysis of a class of periodically switched networks is proposed in the present paper. The basic assumption of GSSA is that the switching frequency must be much higher than the highest natural frequency of the networks, while the input variables can be bounded fast time-varying functions. It is shown in this paper that the GSSA approach generalizes the idea of the averaging technique to overcome the limitations of the conventional state-space averaging method, which prevents us from applying it to quasi-resonant converters (QRCs). The application of GSSA to the analysis of QRCs has been illustrated via examples of the zero-current switching QRC buck converter and zero-voltage switching QRC boost converter. Its accuracy has been verified by numerical simulation and experimental results.

Jianping Xu

Papers

A simple memristor chaotic circuit with complex dynamics

A Current Decoupling Parallel Control Strategy of Single-Phase Inverter With Voltage and Current Dual Closed-Loop Feedback

A Novel PCCM Boost PFC Converter With Fast Dynamic Response

Single-Inductor Dual-Output Buck–Boost Power Factor Correction Converter

A unified averaging technique for the modeling of quasi-resonant converters