PWM DC-DC Converter Research Articles

Enhanced Hysteresis Droop Control for Equivalent Load Sharing in Parallel PWM DC-DC Converters: Optimized Slew Rate by Resonant Filtering

Enhanced Hysteresis Droop Control for Equivalent Load Sharing in Parallel PWM DC-DC Converters: Optimized Slew Rate by Resonant Filtering

Dynamic Sensorless Control Approach for Markovian Switching Systems Applied to PWM DC-DC Converters with Time-Delay and Partial Input Saturation.

This paper provides a detailed analysis of the output voltage/current tracking control of a PWM DCDC converter that has been modeled as a Markov jump system. In order to achieve that, a dynamic sensorless strategy is proposed to perform active disturbance rejection control. As a convex optimization problem, a novel reformulation of the problem is provided to compute optimal control. Accordingly, necessary less conservative conditions are established via Linear Matrix Inequalities. First, a sensorless active disturbance rejection design is proposed. Then, to carry out the control process, a robust dynamic observer-predictive controller approach is introduced. Meanwhile, the PWM DC-DC switching power converters are examined as discrete-time Markovian switching systems. Considering that the system is subject to modeling uncertainties, time delays, and load variations as external disturbances, and by taking partial input saturation into account, the Lyapunov-Krasovskii function is used to construct the required feasibility frame and less conservative stability conditions. As a result, the proposed design provides an efficient control strategy with disturbance rejection and time-delay compensation capabilities and maintains robust performance with respect to constraints. Finally, a PWM DC-DC power converter simulation study is performed in different scenarios, and the obtained results are illustrated in detail to demonstrate the effectiveness of the proposed approach.

Accurate Design of Output Filter for DC–DC PWM Buck Converter and Derived Topologies

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.

An Interleaved Two Switch Soft-Switching Forward PWM Power Converter with Current Doubler Rectifier

Forward converters have been broadly used in the power supply industry due to their simplicity, worthy efficiency, and low cost. A novel prototype soft-switched zero-voltage and zero-current ZVZC PWM DC-DC power converter with low voltage/current stresses is introduced for telecommunication power feeding in this paper. A new two-switch interleaved forward converter circuit is introduced to minimalize current circulation with no supplementary auxiliary snubber circuits. This converter circuit includes some outstanding benefits such as reduced components, improved efficiency, high power density and economic circuit configurations for high power conditioning applications. The simple operation principle is demonstrated on the basis of steady-state analysis. Furthermore, the effective feasibility of the proposed circuit topology is evaluated and verified practically for a 500 W–100 kHz prototype breadboard. The operation principle and steady-state characteristics are demonstrated from a theoretical point of view. To verify the practical effectiveness of the proposed power converter, a 500 W–100 kHz prototype converter using ultrafast IGBTs is implemented for a distributed telecommunication energy plant. The studied soft-switching converter is evaluated in comparison with the previously-proposed PWM converters in terms of voltage, current stresses, and operating efficiency.

Generalized Circuit Averaging Technique for Two-Switch PWM DC-DC Converters in CCM

Design of DC-DC converters like Cuk and SEPIC, which are fourth-order converters, play a vital role in the design of electric vehicle (EV) charging systems and drivers for LED. These converters possess a unique feature of input current being continuous due to the presence of an inductor in series with the supply voltage. In the present work, a generalized approach for obtaining the frequency response of the transfer function of the duty cycle to output voltage (Gvd) for converters operating in continuous conduction mode (CCM) having two switches is proposed. A practical Cuk converter and SEPIC operating in CCM were selected and their analyses in open loop were studied using the LTSpice simulation tool. The behavior of the output voltage and inductor currents under variable ESR’s (equivalent series resistance) of inductors was studied. It was observed that Gvd of these converters was unstable. Hence, an appropriate controller to stabilize the system and achieve a proper gain margin and phase margin in closed-loop operation is required.

Spectral analysis of switch voltage for dual randomized PWM DC-DC converters operating in DCM

ABSTRACT This paper addresses the spectral characteristics of a dual randomised pulse width modulation scheme (RCFM-RPPM) for reducing conducted EMI in the basic DC-DC converters (buck, boost, and buck-boost) operating in discontinuous conduction mode (DCM). It combines two simple schemes, random carrier frequency modulation (RCFM), and a random pulse position (RPPM). First, the modulating principle of the dual randomised PWM is presented. Then, a mathematical model of power spectral density (PSD) that characterises the switch voltage of the three basic DC-DC converters is derived. The mathematical model is validated by simulation of a buck converter operating in DCM. Analytical and simulation results show the effectiveness of PSD spreading of the dual randomised scheme compare to the simple randomised schemes. Moreover, the PSD analysis is confirmed by FFT (Fast Fourier Transform) analysis of the switch voltage. Finally, the effect of randomness levels on the PSD spreading is studied.

Improved Markov Model for Reliability Assessment of Isolated Multiple-Switch PWM DC-DC Converters

This paper proposes a comprehensive Markov model to study the reliability performance of the conventional isolated multiple-switch pulse width modulation DC-DC (IMSDC-DC) converters including full-bridge, half-bridge and push-pull DC-DC topologies. The suggested model helps to achieve more precise outcomes with a better reflection of the real-world operation characteristics by (i) relying on self-embedded fault tolerant capability of the IMSDC-DC converters, (ii) considering the probability of both short and open circuit (SC and OC) faults in each component, (iii) assessing the effect of semiconductors’ SC/OC probability on the converters’ reliability, (iv) analyzing the continuous and discontinuous conduction modes, (v) updating the operational characteristics of the converters after each fault occurrence, and (vi) evaluating control of the converters to have more durable power transfer in some post-fault cases. Then, the model is applied to assess the effects of duty cycle, output power, voltage gain and transformer turns ratio on the overall reliability and mean time to failure. Practical analytic conclusions are followed by some experimental results to verify the accuracy of the proposed model.

Reliability Assessment of Conventional Isolated PWM DC-DC Converters

This paper sets forth the reliability analysis of conventional isolated pulse width modulation DC-DC (IDC-DC) converters. The IDC-DC converters are categorized into isolated single-switch DC-DC (ISSDC-DC) or multiple-switch DC-DC (IMSDC-DC) converters. The proposed framework encompasses analyzing the impacts of duty cycle, input voltage, output power, transformer turns ratio, components characteristics and time duration on the overall reliability performance of the IDC-DC converters. The suggested reliability assessment is centered on Markov models characterized by taking into consideration all open and short circuit faults on the components in both continuous and discontinuous conduction modes. We further investigate the self-embedded fault tolerant capability of the IMSDC-DC converters under open circuit fault scenarios on the switches, diodes and blocking capacitors, where we offer new reliability analytics. Along with extensive analyses and comparisons, several experimental results are provided to verify the self-embedded fault tolerant capability of IMSDC-DC converters.

Simplified Nonlinear Voltage-Mode Control of PWM DC-DC Buck Converter

This paper introduces a new nonlinear voltage-mode controller for a PWM dc-dc buck converter operating in continuous conduction mode. The sliding-mode control technique is used to derive a simplified equivalent control law based on the averaged dc-dc buck converter dynamics. As opposed to the reported design approaches, the proposed control scheme only requires the output voltage in the feedback loop without the need to the capacitor current. Thus, the analogue implementation cost is reduced and the drawback of adding a capacitor current sensor to the power converter is eliminated. The control equation is realized in a simple analogue circuit using few op-amps and resistors, which is suitable for industrial applications. The system modeling and control design procedure along with the derivation of the existence and stability conditions are presented. The control system performance is analyzed using MATLAB and SaberRD simulations. Furthermore, a simple analogue prototype of the simplified nonlinear voltage-mode controlled dc-dc buck converter is developed on a PCB. The simulation and experimental results show that the controller maintains a constant switching frequency, exhibits fast transient response, and provides good tracking performance under large disturbances.

A new soft switching PV module-integrated boost DC-DC converter

This paper introduces a new non-isolated soft switching boost PWM DC-DC converter utilising a switched capacitor edge-resonant cell. The proposed converters can readily fulfil a higher voltage gain due to coupled-inductor which render as a transformer to magnify the voltage gain. At the same time, the boost inductor serves as a resonant inductor. The studied soft switching circuit can achieve a zero-current soft-switching (ZCS) at turning-on and zero-voltage soft-switching (ZVS) at turning-off operations in the used active semiconductor switches. Those beneficial features enable a wider soft-switching range of operation with a higher step-up voltage ratio due to the auxiliary edge-resonance cell, which results in a higher efficiency and low losses. In order to demonstrate the effectiveness of the novel type boost converter, a small laboratory prototype is implemented by simulation and experimental setup using a standard 250-W, 72-cell PV module. Then, the operation performance of the implemented soft switching power converter is examined followed by the design guidelines of the proposed power converter and the results analysis.

Mathematics, Informatics, Science, and Education International Conference (MISEIC) 2019

List of Welcome speech by Rector of Universitas Negeri Surabaya, Welcome speech by Chairman of the Mathemathics, Informatics, Science, and Education International Conference (MISEIC) 2019, of STEACH Keynote Speakers, Current Challenges in the Analysis of High Dimensional Brain Signals, The Effectiveness of the Methods and Approaches of ESD for 2030 Sustainable Development Goals, Key words, Uniqueness and Stability of Stationary Periodic Behavior of PWM DC-DC Converters Using Multifrequency Modelling, MISEIC 2019 Rundown, Images are availble in this pdf.

Averaged Small-Signal Model of PWM DC-DC Converters in CCM Including Switching Power Loss

This brief proposes an improved averaged small-signal model of pulse-width modulated dc-dc power converters operated in continuous-conduction mode, which includes a resistance that corresponds to the switching power loss. Through this model, the switching power loss can be incorporated into existing averaged small-signal dynamic models. The proposed approach is based on the principle of conservation of energy. The expressions for the equivalent switching-loss resistance for the basic converter topologies are derived. The improved dc and small-signal models of the switching network are given. A boost dc-dc converter is considered as an example. The effect of the switching-loss resistance on the small-signal control-to-output transfer function is shown. Experimental results are given and the theoretical predictions have been validated.

Analysis of Recent Advances and Industrial Applications of PWM DC-DC Converters

Analysis of Recent Advances and Industrial Applications of PWM DC-DC Converters

A High Step-up PWM DC-DC Converter With Coupled-Inductor and Resonant Switched-Capacitor

In this paper, a novel high step-up pulse width modulation dc–dc converter integrating coupled-inductor and switched-capacitor (SC) techniques is presented. The proposed converter consists of a synchronous rectification Boost unit and multiple coupled-inductor-SC units. Its structure can therefore be easily extended for ultrahigh voltage gain. The diodes employed in the proposed converter can operate under soft-switching condition by utilizing leakage inductance of the coupled inductor. Low-voltage-rated transistors can be used to improve the efficiency as the voltage stress on the main switches of the proposed converter is reduced. The feasibility of the proposed converter is experimentally demonstrated by a 200 W prototype converter.

High-Frequency Soft-Switching PWM DC-DC Converter with Active Output Rectifier Operating as a Current Source for Arc Welding Applications

This paper introduces a high-frequency soft-switching pulse-width modulation DC-DC power converter with secondary active rectifier tested as a DC current source for arc welding applications. The soft-switching DC-DC converter consists of a high-frequency full-bridge inverter, high-frequency power transformer, and a controlled output rectifier with new secondary energy recovery turn-off snubber. Circulating currents in the converter are reduced by using active rectifier, and RMS values of the currents in primary and secondary switches are decreased by utilizing a novel control algorithm. The experimental results of a 4.5 kW DC-DC converter working at switching frequency of 100 kHz are presented.

A high-efficiency DC-DC converter with LC resonant in the load-side of HFT and voltage doubler for solar PV systems

This paper presents the implementation of a prototype phase-shift soft-switching full-bridge PWM DC-DC power converter isolated by a high-frequency transformer (HFT). This circuit topology is based on a new concept of series resonant principle in the secondary side. The step-up HFT and the voltage doubler rectifier make this circuit suitable for low-voltage renewable sources such as fuel cell or PV applications. Meanwhile, all semiconductor switches can achieve zero-voltage soft-switching (ZVS) with the assistance of transformer leakage inductances and lossless capacitive snubbers. The new contribution of this work is that the passive semiconductor switches (diodes) on the secondary side can also perform ZVS and zero-current switching (ZCS) transitions with the assistance of voltage doubler capacitance. The theory of operation and the experimental setup of the proposed circuit with a rated output of 5 kW are presented and discussed. A comparison between simulation and experimental results is explored and illustrated.

A high-efficiency DC-DC converter with LC resonant in the load-side of HFT and voltage doubler for solar PV systems

This paper presents the implementation of a prototype phase-shift soft-switching full-bridge PWM DC-DC power converter isolated by a high-frequency transformer (HFT). This circuit topology is based on a new concept of series resonant principle in the secondary side. The step-up HFT and the voltage doubler rectifier make this circuit suitable for low-voltage renewable sources such as fuel cell or PV applications. Meanwhile, all semiconductor switches can achieve zero-voltage soft-switching (ZVS) with the assistance of transformer leakage inductances and lossless capacitive snubbers. The new contribution of this work is that the passive semiconductor switches (diodes) on the secondary side can also perform ZVS and zero-current switching (ZCS) transitions with the assistance of voltage doubler capacitance. The theory of operation and the experimental setup of the proposed circuit with a rated output of 5 kW are presented and discussed. A comparison between simulation and experimental results is explored and illustrated.

패시브 공진 스너버를 이용한 플라이백형 ZVS PWM DC-DC 컨버터의 특성해석

In this paper, a high frequency flyback type zero voltage soft switching PWM DC-DC converter using IGBTs is proposed. Effective applications for this power converter can be found in auxiliary power supplies of rolling stock transportation and electric vehicles. This power converter is basically composed of active power switches and a flyback high frequency transformer. In addition to these, passive lossless snubbers with power regeneration loops for energy recovery, consisting of a three winding auxiliary high frequency transformer, auxiliary capacitors and diodes are introduced to achieve zero voltage soft switching from light to full load conditions. Furthermore, this power converter has some advantages such as low cost circuit configuration, simple control scheme and high efficiency. Its operating principle is described and to determine circuit parameters, some practical design considerations are discussed. The effectiveness of the proposed power converter is evaluated and compared with the hard switching PWM DC-DC converter from an experimental point of view and the comparative electromagnetic conduction and radiation noise characteristics of both DC-DC power converter circuits are also depicted.

ZVZCS PWM DC-DC Converter with Controlled Secondary Rectifier for ARC Welding

A zero-voltage, zero-current switching (ZVZCS) PWM DC-DC power converter with secondary active rectifier tested as a dc current source for arc welding is described in this paper. The soft switching DC-DC converter consists of high frequency inverter, high frequency power transformer and controlled output rectifier with new secondary energy recovery turn-off snubber. Circulating current in the converter is reduced by using active rectifier and rms value of the current in secondary switches is decreased by utilizing a novel control algorithm. The experimental results of a 4.5 kW DC-DC converter working at switching frequency of 100 kHz are presented.

Implementation and Analysis of Low Stress PWM DC-DC Converter for Battery Charger

Objective: A highly efficient battery charger is designed using high frequency complementary pulse width modulation. This paper develops a novel soft switching approach to improve the efficiency of the circuit. Methods: The analysis of the newly developed converter is done to develop the mathematical equations. These equations are used to design the converter parameters. In order to reduce the switching losses of the switches during the on and off period, zero voltage switching is employed. All control functions are implemented in microcontroller with a single chip to vary the pulse width of the gate pulses based on the output voltage feedback from the charger unit. Findings: This charger circuit does not increase the conduction losses to reduce the switching losses. Complementary pulse width modulation used to reduce the switching losses which results in wide range of soft switching operation. Zero voltage switching is achieved at all load conditions. Rectifier diodes in the output do not suffer any reverse recovery losses. The proper selection of modes of operation of the circuit helps in reducing the circulating current. Since the circulating current in the primary circuit is eliminated, extra snubber circuit is eliminated from the circuit. The developed battery charger has a simple structure, low cost, easy control and high efficiency. The maximum efficiency is found to be 96%. Conclusion: Simulation and experimental test results of the proposed battery charger shows better efficiency with reduced losses over the traditional pulse width modulation converter.Keywords: Battery Charger, DC Voltage to DC Voltage Converter, Low Stress Across Components, Pulse Width Modulation, Zero Voltage Transition