Boost Converter Operating Research Articles

Q-EDR Hybrid Boost Converter Operation For High Gain With Low Device Stress

Abstract: The hybrid continuous-discontinuous mode (CCM-DCM) operation of non-isolated systems is proposed in this paper. boost converter with quadratic extended duty ratio (Q-EDR) for applications with high gain and low power. The inductors at the input while the EDR was in continuous conduction mode (CCM) The mode of operation of stage inductors is discontinuous conduction. (DCM) in order to reap the advantages of CCM and DCM operation. Interleaving's ripple in the low input current and low voltage The EDR stage switches' stress remains. With what is being half and half method of activity, the inductance worth of EDR stage significant decrease in the inductor. an additional decrease in switch voltage is accomplished during turn-on progress in the proposed activity, prompting huge decrease thus on exchanging losses. This lets the converter run at higher switching speeds. frequency, thereby reducing EDR inductors' size by 45 percent in this instance an experiment confirms the proposed idea. Simulink prototype for a two-phase Q-EDR operating at 30 V-40 V to 400 V output, a gain of more than 12 at duty close to 0.54. The converter has a peak efficiency of 95.5 percent. at a switching frequency of 135 kHz and 300 W for all silicon switches.

Three-Mode Variable-Frequency ZVS Modulation for Four-Switch Buck+Boost Converters With Ultra-High Efficiency

This article introduces a three-mode variable-frequency zero-voltage switching (ZVS) modulation method for the four-switch buck+boost converter. This method makes this circuit concept well suited for applications, such as wireless power charging of electric vehicles, where this circuit operates as a power buffer between the resonant converter and the battery with the function to implement the required charging profile. Herein, the buck+boost converter operation is subdivided into three operating regions according to the converter static voltage gain, i.e., buck-, buck-boost- and boost-type modes. A ZVS turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> triangular current mode (TCM) control is adopted for buck-type and boost-type modes. In the buck-boost-type mode when the input-to-output voltage gain is close to unit, all the possible modulation cases are studied thoroughly based on the phase shift of the two half bridges in a full switching period. The selection of the most suitable modulation scheme is performed to minimize the rms value of the inductor current while taking into account the simplification of the practical implementation. Closed-form equations are derived, which makes it easy to implement in practice. The proposed strategy is described, analyzed, and finally verified through a 3 kW surface mounted device (SMD) silicon carbide (SiC) <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> -based laboratory prototype with designed input voltage of 300–600 V and the typical output voltage of 400 V class battery. The efficiency from the measured results is remarkably high, i.e., between 99.2% and 99.6% in a power range from 1 to 3 kW. Finally, tests for the operating mode transitions demonstrated the feasibility of the proposed modulation method. The power density of this converter is 4.86 kW/L.

Boundary-Based Hybrid Control Algorithm for Switched Boost Converter Operating in CCM and DCM

It is essential to have enhanced efficiency for the DC-DC converters operating in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). This requires a hybrid controller designed using pulse width modulation (PWM) and pulse frequency modulation (PFM) schemes. This paper fixates on a boundary-based hybrid control algorithm for the second-order DC-DC converter - the switched boost converter. The proposed algorithm works in PWM control scheme for CCM operation, whereas DCM operation uses PFM control scheme. The boundary conditions are defined by the load current, output voltage, and switching frequency. Here, an attempt is carried out to have the advantages of both the control schemes. The boost converter is represented by the switched system operating in three modes. Violating transition guards condition orchestrates the switching among these modes. A supervisor detects the CCM and DCM operations, and subsequently switches between PWM and PFM control scheme. Extensive circuit-level simulations are carried out in MATLAB to show the efficacy of the suggested algorithm under the fluctuating line, load, and set-point.

Control strategies and experimental validation for high-gain non-isolated double inductor boost converter

In this paper, a control design methodology for a high-gain non-isolated double-inductor boost converter is proposed. The studied topology of the converter is based on a traditional boost converter operating under the inductor-switched method to obtain a high-voltage gain with a low-duty cycle. Based on the proposed methodology, three control laws are obtained. The proposed control strategies consist of two decoupled control loops: an inner loop aimed to track the input current to a desired current reference and an outer loop addressed to regulate the converter output voltage to a constant reference value. For the inner control loop, first a proportional action is proposed in order to provide damping to the system. In addition, the proportional controller is enhanced using an estimation scheme, based on immersion and invariance theory to deal with the effect of inductor parasitic resistances on the system. The third controller is a proportional-integral action in order to guarantee the current tracking objective. On the other hand, the control design of the output voltage loop results in a PI controller for the three cases which is aimed to regulate the output voltage of the converter. The performance of the proposed control laws is validated in three experimental scenarios: steady-state, input voltage changes and output resistance changes. Output voltage regulation and input current tracking are the main results obtained in each case.

Dynamical Analysis of a Fractional-Order Boost Converter with Fractional-Order Memristive Load

In this paper, a boost converter emulator with a memristive load instead of a resistive load is proposed, and a fractional-order model of the memristive boost converter is created. Firstly, the fractional-order models of the memristor and the memristive boost converter are established respectively, and then based on different switching states, the circuit equations of the fractional-order memristive boost converter operating in continuous conduction mode are derived. Secondly, the dynamic characteristics of the fractional-order system are analyzed by numerical simulations and are compared with the integer-order memristive boost converter. Furthermore, the effects of the memristive load on the system is studied by comparing it to the traditional boost converter with resistive load. The results indicate that the fractional-order memristive boost converter can exhibit rich dynamic behavior by adjusting bifurcation parameters, and the fractional-order circuit system expands the stable working regions of the integer-order circuit system. Meanwhile, the addition of the memristive load significantly widens the normal working regions. Finally, simulations of the fractional-order system circuit based on PSIM further verify the correctness of the theoretical analysis.

A Step-by-Step Design for Low-Pass Input Filter of the Single-Stage Converter

Active power factor correction converters are often introduced as the front stage of power electronic equipment to improve the power factor and eliminate higher harmonics. A Boost or Buck-Boost converter operating in discontinuous current mode is always adopted to achieve high power factor correction. In addition, the input current contains a large amount of higher harmonics, and a low-pass input filter is commonly adopted to filter it out. In this paper, a single-stage high-frequency AC/AC converter is taken as an example to demonstrate the design method of a passive low-pass filter. Firstly, the input side of the grid needs to meet the power factor and harmonic requirements. The preset parameters are set to a range to characterize the performance of the LC filter. The quantitative design method of input filter is proposed and summarized. Moreover, the sensitivity of the filter parameters is analyzed, providing a direction in practical applications. Preset parameters are all proved to conform to the preset range through PSIM simulation. Finally, a 130-W prototype is established to verify the correction of proposed design method. The power factor is around 0.935 and harmonic content in the input current is about 26.4%. All requirements can be satisfied.

A PI + Sliding-Mode Controller Based on the Discontinuous Conduction Mode for an Unidirectional Buck–Boost Converter with Electric Vehicle Applications

This paper solves the buck–boost converter operation problem in the discontinuous conduction mode and the feeding a DC bus of a combined battery/solar-powered electric vehicle grid. Since the sun’s radiation has a very important effect on the performance of photovoltaic solar modules due to its continuous variation, the main task of the system under study is the regulation of the output voltage from an MPPT system located at the output of the panels in order to obtain a DC bus voltage that is fixed to 24 V. This is ensured via a double-loop scheme, where the current inner loop relies on sliding-mode control; meanwhile, the outer voltage loop considers a proportional–integral action. Additionally, the current loop implements an adaptive hysteresis logic in order to operate at a fixed frequency. The closed-loop system’s performance is checked via numerical results with respect to step changes in the load, input voltage, and output voltage reference variations.

A New Modular Structure of Marx Generator Based on Interleaved Boost Converter Operating in Discontinuous Conduction Mode

In this article, a new modular structure of Marx generators (MGs) based on interleaved boost converter is proposed. The converter operates in discontinuous conduction mode to generate a high-voltage pulsed power with a common low-voltage source. Unlimited stages can be added to the proposed structure to reach lower maximum voltage stress for the semiconductors or to generate several kilovolts of the output pulses, while the voltage of the semiconductors remains constant. This structure resulted in a higher pulse repetition rate, fewer semiconductor elements, and lower semiconductor voltage stress in comparison to conventional MGs. Hence, the proposed structure is applicable for and efficient in supplying plasma applications with high-voltage pulses. The theoretical foundation of the introduced converter is presented and its performance is simulated using OrCAD software. Based on the obtained results, the maximum voltage of the output pulse is 40 times the input voltage in a single-stage structure. An 80-W prototype of the proposed structure was built to validate the accuracy of the theoretical foundation and the simulation results.

Nonlinear Stabilization Controller for the Boost Converter with a Constant Power Load in Both Continuous and Discontinuous Conduction Modes.

The operation of Boost converters in discontinuous conduction mode (DCM) is suitable for many applications due to the, among other advantages, inductor volume reduction, high efficiency, paralleling, and low cost. Uses in biomedicine, nano/microelectromechanical, and higher power systems, where wide ranges of input/output voltage and a constant power load (CPL) can coexist, are well-known examples. Under extremely wide operating ranges, it is not difficult to change to a continuous conduction mode (CCM) operation, and instability, chaos, or bifurcations phenomena can occur regardless of the conduction mode. Unfortunately, existing control strategies consider a single conduction mode or linearized models because only slight resistive/CPL power level or input/output voltage variations (and no conduction mode changes) were expected. In this paper, new mathematical models for the Boost converter (with resistive or CPL) that are conduction mode independent are presented and validated. Since the open-loop dynamics of the proposed CPL model is unstable, a nonlinear control law capable of stabilizing the boost converter regardless of the conduction mode is proposed. A stability analysis based on a common-Lyapunov function is provided, and numerical and experimental tests are presented to show the proposal’s effectiveness.

Quasi‐constant bus voltage CrCM boost PFC fed LLC resonant converter in high power LED lighting systems

SummaryThis paper deals with a two‐stage LED (light emitting diode) driver on the basis of front‐end boost converter operating in critical conduction mode (CrCM) and second stage LLC resonant converter for driving an LED lighting load. The boost converter operates in the valley switching mode to reduce switching power loss with less component stress. The ZVS (zero voltage switching) operation of both the half‐bridge semiconductor switching devices reduces the switching losses, which improves the system efficiency. Moreover, to ensure the stability of the DC‐bus voltage, state‐space analysis is also carried out for the CrCM boost converter. The first stage provides the power factor correction (PFC) over the universal AC mains and maintains a constant DC‐bus for the next stage. The second‐stage converter maintains a ripple‐free output voltage to an LED load. This circuit has reasonably minimized the design complexity as compared with single‐stage variable DC‐bus PFC integrated resonant converters and also gives improved efficiency in an isolated configuration. In order to validate the system, a 150‐W prototype is investigated, and experimental findings are analyzed in‐line with theoretical results at universal AC mains.

Linear Superposition Compensation Strategy to Optimize Transient Response for Critical Conduction Mode Boost Converter

For boost converter operating in the Critical Conduction Mode (CRM), linear compensation strategy is widely used to improve the control performance. However, conventional linear compensation is designed for limited input, since transfer functions for different input are often incompatible. In this paper, transient responses with respect to input/reference voltage and load variations are optimized simultaneously by a linear superposition compensation strategy. The objective closed-loop transfer functions for each kind of variations are investigated, which contribute to the overall compensation loop design. According to linear superposition principle, the compensation results are summed as reference current, based on which the switching on/off time is modulated. Although the summed results are convergence, separate compensation loop that includes integral terms can lead to divergence in calculation process. To eliminate the potential divergence, the overall compensation loop is re-designed so as to suit digital implementation. Experimental results show that the linear superposition compensation strategy achieves great transient performance to different kind of variations.

Hybrid Tuning of a Boost Converter PI Voltage Compensator by Means of the Genetic Algorithm and the D-Decomposition

In this paper the D-decomposition technique is investigated as a source of non-linear boundaries used with the Genetic Algorithm (GA) search of a PI voltage compensator gains of the boost converter operating in Continuous Conduction Mode (CCM). The well known and appreciated boost converter has been chosen as a test object due to its right-half plane zero in the control-to-output (c2o) voltage transfer function. The D-decomposition, as a technique relying on the frequency sweeping, clearly indicates not only the global stability but, in its extended version, regions satisfying the required gain (GM) and phase (PM) margins. Such results are in form of easy to interpret functions KI=f(KP). The functions are easy to convert to the GA constraints. The GA search, with three different performance indexes as the fitness functions, is applied to a control structure with time delays basing on identified c2o voltage transfer functions. The identification took place in an experiment and in simulation. Outcomes of the identification are compared to mathematically derived formula taking into account certain parasitics. A complete set of practically useful mathematical formulas together with their validation in simulation and experiment is included.

Improved and accurate low‐frequency average modelling and control of a conventional power factor correction boost converter in continuous conduction mode

When dealing with power factor correction (PFC) rectifiers that require the use of high filter capacitances, conventional small-signal modelling techniques are not capable of reproducing the converter behaviour accurately owing to the impact of the low-frequency dynamics on the system. In this context, this work presents an improved modelling technique applied to a conventional PFC boost converter operating in continuous conduction mode (CCM). The proposed approach leads to a more accurate analysis than the traditional modelling developed for dc–dc converters, which is often extended to rectifiers. It consists of a fast and concise solution for the implementation of several PFC techniques from the derived transfer functions. The introduced method is described aiming at the development of a boost-based PFC stage using the well-known one-cycle control technique (OCC). Simulation and experimental results are presented and thoroughly discussed to validate the theoretical assumptions.

In‐depth analysis of an RCD snubber applied to a DC‐DC boost converter

SummaryResistor‐capacitor‐diode (RCD) snubbers are traditionally used in practice aiming to maintain the stresses on semiconductors within safe operating limits. However, a serious drawback is the power lost in the resistor, which may affect the converter efficiency significantly. In this context, this work proposes a detailed procedure for the accurate design of an RCD snubber based on two additional key parameters that are not considered in typical guidelines provided in didactic books, that is, the forward recovery time of the main diode and the inductor current ripple. The impact of the maximum additional voltage spike on the switch is first assessed considering that it influences both the power dissipated in the snubber resistor and the current stresses on all semiconductors. A systematic optimization of the design is presented later on, considering that proper tradeoffs can be made among the type of main diode used in the converter, the maximum voltage spike on the switch, and the inductor current ripple as demonstrated mathematically. A dc‐dc boost converter operating in continuous conduction mode (CCM) is thoroughly analyzed so that is possible to derive a consistent methodology comprising all power stage elements. This study intends to shed new light on an old research topic, as well to investigate the snubber impact on the converter operation and overall performance. The effectiveness of the proposed approach is demonstrated experimentally employing a laboratory prototype rated at 200 W. The results clearly show that is possible to optimize the design as desired, with good overall performance over a wide load range considering all aforementioned aspects.

Influence of MOSFET Parasitic Capacitance on the Operation of Interleaved ZVS Boost Converters

Interleaved zero-voltage switching boost converters have been known for over 20 years. However, the influence of parasitic capacitance of transistors has not been described. In this paper the converter is analyzed and the equation for voltage ratio is derived for any number of converter phases. First a general description of the topology, including main voltage and current waveforms, is provided. Subsequently the converter is analyzed and conditions for soft switching are derived. Next the analysis results are compared to measurements of an experimental converter setup. Discrepancies are identified and the influence of parasitic capacitance is analyzed. By considering the parasitic capacitance the difference between experimental and analytical results of voltage ratio is reduced from 0.2 to less than 0.05.

Design issues and performance analysis of CCM boost converters with RHP zero mitigation via inductor current sensing

The right-half plane (RHP) zero in the control to output voltage transfer function of a boost converter operating in the continuous conduction mode limits the loop bandwidth. By injecting a scaled version of the inductor current into the loop, it is possible to shift the zero from the right-half plane to the left-half plane, which leads to increased stability of the control loop. This solution generates a static voltage error at the output of the converter (tracking error), which may be unacceptable in practical applications. A few strategies to mitigate or correct this tracking error have been suggested. However, they have never been fully assessed. This paper thoroughly investigates the impact of the RHP zero mitigation technique on the dynamic performance of a boost converter, and identifies the complex trade-off between the system stability, transient response, and tracking error correction capability. Based on these findings, design guidelines are provided to help maximize system performance. A representative case study is considered to highlight the performance benefits and simulation results are presented to validate the analysis.

A New Variable Frequency Zero Voltage Switching Control Method for Boost Converter Operating in Boundary Conduction Mode

This paper proposes a new variable frequency zero voltage switching (ZVS) control method for boost converter operating in boundary conduction mode (BCM). The intended method keeps the converter in BCM despide of the load and input voltage variations. This is done by changing switching frequency in a certain specified range. The proposed method can guarantee circuit performance in BCM via zero-crossing detection of the inductor current and changing the switching frequency. In addition, with a slight modification in control structure, it is possible to achieve a fully ZVS in all cases. This converter control is carried out in analog form without using microprocessors which, compared with the digital one, has less noise, cost and processing challenges in high frequency applications. Simulation results obtained from applying the proposed method on a GaN-based synchronous boost converter in two different switching frequency ranges (100KHz and 1MHz) are indicative of the proposed strategy advantages.

Adaptive damping tuning and circuit implementation for broad bandwidth energy harvesting

This paper presents a circuit to tune the electrical damping for optimal power harvesting at time varying excitation frequencies. Optimization of parameters, such as electrical damping to match the mechanical damping and the resonant frequency to match the excitation frequency have long been known. However, the electrical damping optimized at the resonant frequency is not necessarily the optimum point when the excitation frequency changes. This result is especially important in vibration energy harvesting systems since the vibration source is generally not at a single fixed frequency. The proposed circuit detects the excitation frequency and tunes the electrical damping based on a function, obtained from mechanical system modeling and simulation. A frequency detection circuit and a boost converter operating in critical conduction mode are used. Both modeling and experiment results show that the impedance tuning circuit provides the required optimal damping at different excitation frequencies and achieves a much broader bandwidth compared with the conventional system. When the excitation frequency increases to 1.1–1.4 times the natural frequency, the proposed adaptive damping tuning increases the power output by 30%–100% compared to the traditional one.

Cascade Connection of Boost Converters Operating in Discontinuous Conduction Mode for Portable Loads

In recent years, the design of new electronic equipment requires the development of new topologies for power supplies. The above is clear for portable equipment, which many times is classified as light loads. These new applications require power supplies with wide conversion ratios and better efficiencies. A solution to this problem is the use of two or more conventional converters connected in cascade, which have been proposed to operate in continuous conduction mode; however, if these converters operate in discontinuous conduction mode (DCM) a better efficiency is achieved. In this paper, a cascade connection based on two boost converters operating in DCM is proposed. A step‐by‐step procedure for the proper design of the cascade connection is given. Simulation and experimental results for a low power converter validate the proposed methodology. Thus, the design procedure will help in designing converters for light power applications. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Experimental Verification of Robust PID Controller Under Feedforward Framework for a Nonminimum Phase DC–DC Boost Converter

This article addresses the disturbance rejection problem of a nonminimum phase dc-dc boost converter operating in the continuous conduction mode (CCM) using a novel robust proportional-integral-derivative (PID) controller design method. The proposed idea is to design the controller using the equivalent feedforward formulation of the modified direct synthesis (MDS) approach. The advantages of the proposed MDS design are: 1) systematic incorporation of disturbance dynamics and the converter dynamics explicitly in the controller design to reduce the complex tuning effort of the controller parameters; 2) allowing the converter to operate close to the performance limit set by the zero in the right half-plane (RHP); 3) the closed-loop performance specifications can be incorporated into the desired loop response using only single tuning parameter based on Bode's gain crossover frequency inequality; 4) attenuates the loop gain to improve the disturbance rejection; and 5) realization of controller requires only output voltage as a feedback signal. The strength of the proposed MDS method is compared with the internal model control (IMC) method in both simulations and experiments. Based on these responses, the proposed PID ensures robust performance to the model-plant mismatch and allows the output voltage to quickly recover back to the operating voltage in the presence of external disturbances with less inductor current.