Boost Power Converter Research Articles

Solar Power Generation System With Power Smoothing Function

The output power from a solar power generation system (SPGS) changes significantly because of environmental factors, which affects the stability and reliability of a power distribution system. This study proposes a SPGS with the power smoothing function. The proposed SPGS consists of a solar cell array, a battery set, a dual-input buck-boost DC-AC inverter (DIBBDAI) and a boost power converter (BPC). The DIBBDAI combines the functions of voltage boost, voltage buck and DC-AC power conversion. The BPC acts as a battery charger between the solar cell array and the battery set. For the proposed SPGS, the DC power that is provided by the solar cell array or the battery set is converted into AC power through only one power stage. The solar cell array also charges the battery set through only one power stage. This increases the power conversion efficiency for the solar cell array, the battery set and the utility. The battery set is charged/discharged when the output power of the solar cell array changes drastically, in order to smooth the output power from the SPGS. In addition, the DIBBDAI can suppress the leakage current that is induced by the parasitic capacitance of the solar cell array. The proposed power conversion interface increases power efficiency, smooths power fluctuation and decreases leakage current for a SPGS. A hardware prototype is completed to verify the performance of the proposed SPGS.

Sliding Mode Control Based on Linear Extended State Observer for DC-to-DC Buck–Boost Power Converter System With Mismatched Disturbances

This article presents a new control strategy merging a sliding mode control (SMC) with a linear extended state observer (LESO) to regulate the output voltage of the buck–boost power converter system affected by matched and mismatched disturbances. The SMC–LESO schema uses the input–output linearization approach and the equivalent control method to determine the boundary layer around the sliding surface. This boundary layer depends on the sliding surface and the equivalent control value, depending on the estimated variables obtained through a LESO. With this schema, the unknown matched, and mismatched disturbances are observed and compensated by an adaptation of the SMC. The proposed approach minimizes the sliding surface chattering and improves the performance against sudden static and dynamic load changes as well as voltage variations on the power supply input. An experimental comparison with traditional sliding mode control and classical proportional–integral–derivative control is performed, confirming the proposal's effectiveness. The closed-loop stability (observer-controller-plant) is guaranteed in the input-to-state stability framework.

Power Factor Corrected by Buck-Boost Converter type Battery Charger Employing PWM Technique with Capacitor Bank

In this paper, a buck-boost type battery charger is developed for charging battery set with a lower voltage. This battery charger is configured by a rectifier circuit, an integrated boost/buck power converter and a switched capacitors circuit. A boost power converter and a buck power converter sharing a common power electronic switch are integrated to form the integrated boost/buck power converter. By controlling the common power electronic switch, the battery charger performs a hybrid constant-current/constant-voltage charging method and gets a high input power factor. Accordingly, both the power circuit and the control circuit of the developed battery charger are simplified. The switched capacitors circuit is applied to be the output of the boost converter and the input of the buck converter. The switched capacitors circuit can change its voltage according to the utility voltage so as to reduce the step-up voltage gain of the boost converter when the utility voltage is small. Hence, the power efficiency of a buck-boost type battery charger can be improved. Moreover, the step-down voltage gain of the buck power converter is reduced to increase the controllable range of the duty ratio for the common power electronic switch. A prototype is developed and tested to verify the performance of the proposed battery charger

Simplified cascade multiphase DC-DC boost power converters for high voltage-gain and low-ripple applications

This paper proposes two new simplified cascade multiphase DC-DC boost power converters with high voltage-gain and low ripple. All simplifications reduce the number of active switching devices from <em>2N</em> into <em>N</em>, where <em>N</em> is the phase number. The first simplification reduces the number of inductors from <em>2N</em> into <em>N+1</em> and increases the number of diodes from <em>2N</em> into (<em>2N+1</em>). The second simplification reduces the number of inductors from <em>2N</em> into <em>N+1</em> and increases the number of diodes from <em>2N</em> into (<em>3N+1</em>). The second simplification needs inductors with smaller current rating than the first simplification. The expressions of output voltage as a function of load current are derived by taking into account the voltage drops across the inductors and switching power devices. Simulated and experimental results are included to show the basic performance of the proposed cascade multiphase DC-DC boost power converters.

A modified Cuk DC-DC converter for DC microgrid systems

A new efficient step-updirect current-direct current (DC-DC) power converter that is suitable for DC microgrid systems is proposed in this paper. The proposed step-up DC-DC converter is derived from the conventional Cuk DC-DC power converter. Output voltage analysis that is useful to predict the conduction losses is presented. It is shown that the proposed step-up DC-DC converter is more efficient than the conventional DC-DC boost power converter. Current ripple analysis that is useful to determine the required inductors and capacitors is also presented. Experimental results are included to show the validity of the proposed step-up DC-DC power converter.

Improving the Fuel Economy and Battery Lifespan in Fuel Cell/Renewable Hybrid Power Systems Using the Power-Following Control of the Fueling Regulators

In this study, the performance and safe operation of the fuel cell (FC) system and battery-based energy storage system (ESS) included in an FC/ESS/renewable hybrid power system (HPS) is fully analyzed under dynamic load and variable power from renewable sources. Power-following control (PFC) is used for either the air regulator or the fuel regulator of the FC system, or it is switched to the inputs of the air and hydrogen regulators based on a threshold of load demand; these strategies are referred to as air-PFC, fuel-PFC, and air/fuel-PFC, respectively. The performance and safe operation of the FC system and battery-based ESS under these strategies is compared to the static feed-forward (sFF) control used by most commercial strategies implemented in FC systems, FC/renewable HPSs, and FC vehicles. This study highlights the benefits of using a PFC-based strategy to establish FC-system fueling flows, in addition to an optimal control of the boost power converter to maximize fuel economy. For example, the fuel economy for a 6 kW FC system using the air/fuel-PFC strategy compared to the strategies air-PFC, fuel-PFC, and the sFF benchmark is 6.60%, 7.53%, and 12.60% of the total hydrogen consumed by these strategies under a load profile of up and down the stairs using 1 kW/2 s per step. For an FC/ESS/renewable system, the fuel economy of an air/fuel-PFC strategy compared to same strategies is 7.28%, 8.23%, and 13.43%, which is better by about 0.7% because an FC system operates at lower power due to the renewable energy available in this case study.

Improved Power Converter of SRM Drive for Electric Vehicle With Self-Balanced Capacitor Voltages

The regulation of phase currents is bound by the voltage of power source for switched reluctance motor (SRM) drive with conventional asymmetric half-bridge (AHB) power converter in electric vehicle (EV). To avoid the drawback, an improved active boost power converter with self-balanced capacitor voltages is proposed. First, the problems existing in the AHB power converter are analyzed in different stages of each phase current. Then different working modes of the proposed converter are investigated. The corresponding control strategies are implemented in the light of two conduction sequences. The reference phase voltage is obtained with a new method. Then the control signals of the front-end topology are generated by comparing the reference phase voltage with the required value. One significant advantage of the proposed converter is that it can provide different voltages according to the operation condition of SRM dynamically. The other is that the maximum phase voltage the converter can boost is up to three times the supplied voltage. Comparative experiments on a three-phase 12/8 SRM drive validate the performance of the converter and the effectiveness of the control strategies.

Sistema de recuperación de energía basado en emular el movimiento del flujo de agua en tuberías

Energy production is an important factor for the development of productive activities, transformation and services in the country, whose generation and consumption increases year by year, which leads to the use of clean energy more and more. Hydropower as a portable application option contributes little to energy production in industries or homes, so this situation presents an opportunity for the development of adaptive power generation systems that take advantage of the movement of water. In the present work, a test bench based on an energy recovery system was developed, which consists of simulating the flow of water that exists in the pipes in order to generate electrical energy through mechanical movement by coupling a permanent magnet generator, where the behavior of a turbine interconnected to a pipeline was emulated, through a DC motor whose speed is controlled through a power chopper. A storage and power conversion was developed, integrating a rectifier module with filter which converted the signal from alternating to direct, which would later be the input of a Buck reducing CD-CD converter, which has high efficiency and allows to reduce the voltage stabilized at 5V. To complete the storage system at different loads, a Boost power converter module was used which raises and converts the signal from CD to CD, obtaining a voltage output greater than its input, this energy can be stored in batteries and in the same way be used to power any CD device, thus allowing us to save a part of the energy that is consumed when transporting water in a pipe.

Hydrogen Fuel Cell and Ultracapacitor Based Electric Power System Sliding Mode Control: Electric Vehicle Application

Control of a perturbed electric power system comprised of a hydrogen fuel cell (HFC), boost and boost/buck DC–DC power converters, and the ultra-capacitor (UC) is considered within an electric vehicle application. A relative degree approach was applied to control the servomotor speed, which is the main controllable load of the electric car. This control is achieved in the presence of the torque disturbances via directly controlling the armature voltage. The direct voltage control was accomplished by controlling the HFC voltage and the UC current in the presence of the model uncertainties. Controlling the HFC and UC current based on the power balance approach eliminated the non-minimum phase property of the DC–DC boost converter. Conventional first order sliding mode controllers (1-SMC) were employed to control the output voltage of the DC–DC boost power converter and the load current of the UC. The current in HFC and the servomotor speed were controlled by the adaptive-gain second order SMC (2-ASMC). The efficiency and robustness of the HFC/UC-based electric power systems controlled by 1-SMC and 2-ASMC were confirmed on a case study of electric car speed control via computer simulations.

Mechanism Model and Prediction Method of Common Mode Radiation for a Nonisolated Very-High-Frequency DC–DC Converter With Cables

Research on electromagnetic interference of high-frequency power converters remains a challenging and important topic, particularly in light of rapidly emerging wide band-gap power devices operating with ns level turn- on /turn- off times. Building on the substantial contributions that have been made on the formation mechanisms of common mode (CM) radiation, a new mechanism for an equivalent CM driving voltage source caused by imbalanced conductors or components is proposed. Applying this mechanism, the CM driving voltage source model of a nonisolated boost dc/dc power converter with input/output cables is introduced. The CM far-field electric strength algorithms of an asymmetric cable antenna are theoretically analyzed and derived in detail. Subsequently, a prototype for a low-power 30-MHz very-high-frequency boost power converter based on gallium nitride is built and its 10-m CM far-field radiation strength is predicted according to the proposed model. The radiation pattern characteristics are analyzed and several radiation suppression methods are also designed. The comparison with the measured radiation results shows that the proposed CM radiation model and the prediction method achieve good effect below 300 MHz.

Enhanced Time-Invariant Linear Model for the EMI Prediction of Switching Circuits

This article presents an innovative technique for the black-box modeling of the conductive emissions of switching circuits from external observations. The proposed methodology relies on the robust and elegant theory of periodically switched linear systems, providing the user with a tool for the generation of frequency-domain augmented linear time-invariant equivalents. The obtained models offer both a remarkable accuracy for different supply conditions and a deep understanding of the inherent switching mechanisms of this class of devices. The proposed framework also enables the derivation of a simplified enhanced Norton representation which outperforms the classical state-of-the-art models based on linear time-invariant approximations. Model parameters are computed via a blind procedure based only on two measurements. The feasibility and strength of the proposed approach are demonstrated on a dc–dc boost power converter and on a dc electrical motor via the prediction of their conducted disturbances.

Reciprocal and Self-Aging Effects of Power Components on Reliability of DC–DC Boost Converter With Coupled and Decoupled Thermal Structures

Reliable and unceasing exploitation of power electronic converters plays a major part in numerous applications. The aging effects on the performance of a dc–dc boost power converter with different thermal structures are under consideration in this study. This article demonstrates the feasibility of using sensitivity analysis for a much more accurate estimation of the power converters’ performances. This article deals with a dc–dc boost converter as a case study in two thermal structures (coupled and decoupled) for electric vehicle application. Significant self and reciprocal effects of components can immensely affect the reliability assessment in thermal coupled structures. It reveals that the useful lifetime of the insulated-gate bipolar transistor (IGBT) and the diode can decrease by 35% and 44%, respectively. In thermal decoupled structures, there are no significant reciprocal effects either in electrical or thermal operating points (EOP/TOP). The results reveal the importance of reciprocal aging and self-aging effects on the reliability assessment in coupled thermal structures.

A new approach for the diagnosis of different types of faults in dc–dc power converters based on inversion method

This paper presents theory, a new approach and validation results for fault detection and isolation (FDI) in dc–dc power converters, based on inversion method. The developed method consists on the inversion-based estimation of faults and change detection mechanisms adapted to the power converters context. With the inverse model of a switched linear system, we have designed a real-time FDI algorithm with an integrated fuzzy logic scheme which detects and isolates abrupt changes (faults) at unknown time instants. A smoothing strategy is used to attenuate the effect of unknown disturbances and noise that are present at the outputs of this inverse model. Once the fault event is detected, a dedicated fuzzy-logic-based scheme is proposed to isolate the four types of faults: switch, voltage and current sensor, and capacitor. The performance of the proposed method is verified experimentally to detect and isolate the mentioned faults in the dc–dc boost power converter.

An Active Boost Power Converter for Improving the Performance of Switched Reluctance Generators in DC Generating Systems

In this article, an active boost power converter is proposed for switched reluctance generators (SRGs) that support low-voltage dc loads or dc microgrids. In the proposed converter, a front-end circuit is added to a conventional asymmetric half bridge power converter. With the front-end circuit, excitation voltage and demagnetization voltage can be regulated flexibly to improve the system efficiency and increase the maximum output power under constant phase current constraints. Then a multiloop control strategy is developed to control the power converter. The multiloop controller contains a power controller and a boost voltage controller. The power controller is designed to control SRG over the entire operating range. The boost voltage controller is designed to control the front-end circuit. Two strategies are compared for the boost voltage control: voltage hysteresis control strategy and power flow control strategy. Comparing with voltage hysteresis control, proposed power flow control shows improvements in minimizing output voltage ripple and is suggested for the proposed converter. In the end, simulation and experimental results are given to verify the feasibility of the proposed power converter and control strategy. Comparisons between the proposed converter and the conventional converter are also given for evaluation.

Evaluation of an optical energy harvester for SHM application

In this paper a preliminary study on an array configuration of rectified optical nanoantennas for energy harvesting application is proposed. Currently, the major impediments for the use of the rectified optical nanoantenna known as rectenna are the relatively low conversion efficiency and low power transfer to the load, both of them caused mainly by the mismatch between the impedance of the rectifier (several kilo ohms) and that of the antenna (hundreds of ohm). For this reason, the design of the array represents a crucial point to obtain the maximum energy transfer from the rectenna to the load, represented as a typical DC/DC boost power converter, and modeled by an equivalent input impedance. The novelty of this study confirms that it is possible to obtain dynamically an impedance matching between the array of optical rectennas and the load. According to this method, in the proposed rectenna array, N elements can be serially connected so to allow to the open circuit voltage to be increased and M elements can be parallel connected to give the degree of freedom needed to achieve the impedance matching with the load. Finally, a case study for Structural Health Monitoring (SHM) application is presented.

Efficient fuel economy strategies for the Fuel Cell Hybrid Power Systems under variable renewable/load power profile

The adaptive energy management strategies proposed in this paper are based on a 2-dimensional (2D) optimization function designed for fuel economy of the fuel cell hybrid power system operating under the variable power profiles of renewable energy sources and loads, which will define the dynamic power profile on the DC bus. The power-following control is designed to mitigate the variability of the DC power based on the DC power flow balance, so the energy management unit generates the power-following reference and two other references for searching the optimum, which are used to control the inputs for the boost power converter and for the air and fuel regulators. All three energy management 2D strategies obtained by selecting the mentioned references to the controlled inputs of the fuel cell system are analyzed and compared with the types 1D and other reference strategies reported in literature using the fuel economy as a performance indicator. For example, the fuel economy for a 6 kW load cycle is of 42 and 18 L for the strategies 2D-RTO1 and 2D-RTO2 compared to the benchmark strategy based on static feed-forward control.

Current balancing control for an interleaved boost power converter

ABSTRACTThe interleaved boost power converter has the advantages of ripple cancellation and better efficiency. The major problem of the interleaved boost power converter is the current balancing among different phases of the boost power converters. In this paper, a current balancing control method for equalizing the currents of two-phase interleaved boost power converter is proposed. The output current can effectively detect the mismatch between the boost power converters for the interleaved boost power converter. The output current is used to perform both the current balance and the current-mode control. The salient feature is that only one current sensor is used in the proposed current balancing control method. A hardware prototype is developed, and the experimental results verify the performance of the proposed current balancing control method is as expected.

Sliding Mode Output Regulation for a Boost Power Converter

This work deals with the novel application of the sliding mode (discontinuous) output regulation theory to a nonlinear electrical circuit, the so-called boost power converter. This theory has excelled due to the fact that trajectory tracking plays a central role. The control of a boost power converter for the output tracking of a DC biased sinusoidal signal is a challenging problem for control engineers. The main difficulties are the computation of a proper reference signal for the inductor current, and the stabilization of the inductor current dynamics or to guarantee the correct output tracking of the capacitor voltage. With the application of the discontinuous output regulation these problems are solved in this work. Simulations and real time experiments were carried out with an unknown variation of the DC input voltage, where the good output tracking of the capacitor voltage was verified along with the stabilization of the inductor current. The discontinuous output regulation theory has proven to be a suitable tool in the output tracking for the boost power converter.

On the Teixeira singularity bifurcation in a DC–DC power electronic converter

The electronic circuit of a DC–DC boost power converter under a specific sliding mode control strategy is analyzed. This circuit is modeled as a discontinuous piecewise linear three-dimensional dynamical system, whose state space is divided into two open regions by a plane acting as the switching manifold. This system displays sliding motion confined to the switching manifold and limited by two straight lines where lie the points of tangency, one for each involved linear vector field. Such tangency lines can intersect transversally on a invisible two-fold point known as Teixeira singularity. Our goal is to investigate an interesting bifurcation that occurs on the Teixeira singularity, involving both a pseudo-equilibrium point and a crossing periodic orbit. This bifurcation, named TS-bifurcation, occurs when a pseudo-equilibrium point of the discontinuous piecewise linear system, capable of moving between the attractive and repulsive sliding regions as a result of the change in a parameter, collides with the Teixeira singularity. Simultaneously, a periodic orbit arises from the Teixeira singularity crossing the switching manifold in two points. Apart from the TS-bifurcation characterization in the DC–DC converter, we have numerically detected other non-local phenomena like a saddle-node bifurcation of crossing limit cycles. Experimental results to illustrate the effects of the TS-bifurcation on the dynamics of a power electronic converter are also shown.

Minimal order controllers for output regulation of nonlinear systems

This paper is about the nonlinear local error feedback regulator problem. The plant is a nonlinear finite-dimensional system with a single control input and a single output and it is locally exponentially stable around the origin. The plant is driven, via a separate disturbance input, by a Lyapunov stable exosystem whose states are nonwandering. The reference signal that the plant output must track is a nonlinear function of the exosystem state. The local error feedback regulator problem is to design a dynamic feedback controller, with the tracking error as its input, such that (i) the closed-loop system of the plant and the controller is locally exponentially stable, and (ii) the tracking error tends to zero for all sufficiently small initial conditions of the plant, the controller and the exosystem. Under the assumption that the above regulator problem is solvable, we propose a nonlinear controller whose order is relatively small — typically equal to the order of the exosystem, and which solves the regulator problem. The emphasis is on the low order of the controller. In contrast, previous results on the regulator problem have typically proposed controllers of a much larger order. The stability assumption on the plant (which can be relaxed to some extent) is crucial for making it possible to design a low order controller. We will show, under certain assumptions, that our proposed controller is of minimal order. Three examples are presented — the first illustrates our controller design procedure using an exosystem whose trajectories are periodic even though the state operator of the linearized exosystem contains a nontrivial Jordan block. The second example is more involved, and shows that sometimes a nontrivial immersion of the exosystem is needed in the design. The third example, based on output voltage regulation for a boost power converter, shows how the regulator equations may reduce to a first order PDE with no given boundary conditions, but which nevertheless has a locally unique solution.