PWM DC-DC Converter Research Articles

A PWM DC-DC converter with optimum segmented output stage and current detector

High efficiency is very important for DC-DC power supplies in portable applications. A PWM DC-DC converter with optimum segmented output stage is proposed in this paper whose efficiency at light load is improved. The segmented output stage is optimally divided into 5 small segments plus 4 big segments. The segmented number of the output stage can be adaptively regulated according to the load current. Moreover, two current detector circuits are simultaneously adopted to form a mixed load current sensor in the converter to improve the detecting accuracy. A segmented current SenseFET (SCS) is used to sense the load current in continuous current mode, and a time digital converter with digital judgement (TDC-D) is designed to detect the load current in discontinuous current mode. The structure of the proposed PWM converter with optimum segmented output stage and mixed load current detector circuits is described in this paper, which has been implemented in a 0.13μm CMOS process. Simulation and testing results show that the output stages of the PWM converter can self transit from one segment stage to another segment stage according to the load condition. And the maximum efficiency improvement of the proposed converter can reach 15%.

Comparative Analysis of Fixed Speed & Variable Speed Response of PFC Zeta Converter Fed PMSM Drive Using PI Controller

In several PWM DC-DC converter topologies, the controlling switches are operated in switch mode wherever they're needed to conduct the whole load current on and off throughout every switching cycle. Recently there is an enlarged interest within the use of resonant kind DC-DC converters due to the benefits of high efficiency, small size, lightweight, reduced Electro Magnetic Interference (EMI) and low component stresses. A novel PFC (Power factor Corrected) converter feeding a PMSM drive employing a single voltage sensing element is proposed for variable speed applications. It consists of single phase supply followed by uncontrolled bridge rectifier and a Zeta DC-DC converter is employed to regulate the voltage of a DC link capacitance that is lying between the Zeta converter and a VSI (Voltage source Inverter). The voltage of a dc-link capacitor of zeta converter is controlled to realize the speed control of PMSM Drive. The zeta converter is functioning as a front end device operating in DICM (Discontinuous inductor Current Mode) and therefore employing a voltage follower. Using MATLAB/ Simulink 7.13 environment the model can be simulated to achieve a wide range of speed control.

A High Frequency-Link Secondary-Side Phase-Shifted Full-Range Soft-Switching PWM DC–DC Converter With ZCS Active Rectifier for EV Battery Chargers

A new prototype of a secondary-side phase shift soft-switching PWM dc-dc converter suitable for electric vehicle battery charging systems is presented in this paper. Wide range soft-switching operations are achievable from full load to no load by effectively utilizing the parasitic inductances of the high frequency transformer in the proposed dc-dc converter. In addition, no circulating current occurs in both of the primary and secondary side full-bridge circuits; thereby, the related idling power can be minimized. As a result, high efficiency power conversion can be maintained owing to the full range soft-switching operation and wide range output power and voltage regulations. Its operating principle is presented on the basis of theoretical analysis and simulation results, and the design procedure of the circuit parameters of the proposed dc-dc converter is described. The essential performance and its effectiveness of the proposed dc-dc converter are originally demonstrated from a practical point of view in an experiment using a 1 kW-50 kHz laboratory prototype.

Operation Analysis of Soft Switching PWM DC-DC Converter with Secondary Snubber

The paper deals with analysis of operation of a soft switching PWM DC-DC full-bridge converter with new energy recovery turn-off snubber on secondary side of high frequency power transformer.Principal equations are derived for individual operation states. On the basis of them the diagrams are made out. The diagrams give complex image on the converter behaviour during whole period of operation at nominal load. Theoretical waveforms are compared with simulation results.

하이브리드형 압전 변압기의 고주파 승압 초퍼를 이용한 적응제어기법 유도전동기 속도 센서리스 벡터제어에 관한 연구

In this paper, recently, it is described to the piezoelectric transformer technology develops, because it was have to favorable characteristics such as electromagnetic-noise free, compact size, higher efficiency, and superior power density, flux linkage, noiseless, etc. its resonance frequency was used to output waveform of a sine wave. A rotor speed identification method of induction motor based on the theory of flux model reference adaptive system(FMRAS). The estimator execute the rotor speed identification so that the vector control of the induction motor may be achieved. The improved auxiliary variable of the model are introduced to perform accurate rotor speed estimation. The control system is composed of the PI controller for speed control and the current controller using space voltage vector PWM techniuqe and DC-DC converter. High speed calculation and processing for vector control is carried out by digital signal one chip microprocessor. Validity of the proposed control method is verified through simulation and experimental results.

Zero$^{\rm th}$-Order Control of Boost DC-DC Converter With Transient Enhancement Scheme

This paper proposes a new control scheme of zeroth-order control (ZOC) for PWM DC-DC converters in which the pole frequencies of the control loop are no longer dependent on the values of the inductor, output capacitor, or the output load current. In the proposed scheme, the output voltage of the converter is regulated by a comparator. The main control loop of the converter regulates the inductor energy which is built up to an optimum value to be delivered to the output by means of the time interval between the rising edge of the main switch driving pulse and the comparator output pulse. A boost DC-DC converter with the proposed ZOC has been implemented and fabricated in a commercial 0.35 μm BCDMOS process. A maximum efficiency of 88% is achieved at a total output power of 480 mW with the switching frequency of 833 kHz when the input voltage and the output voltage are 3.7 V and 8 V, respectively. Over 85% efficiency is maintained for a wide range of the output load current from 40 mA to 300 mA.

Time-domain identification of pulse-width modulated converters

A discrete time domain-based system identification method for PWM DC-DC converters is proposed. Accurate information on the system's open-loop response is essential in the design of the system controller in order to obtain the desired closed-loop response. This is especially true in switch-mode converters where component uncertainty exists. It is conjectured in this study that an identification method that is based on time-domain signals will be relatively simple to realise with a digital processor. The method that is proposed is capable of successfully reconstructing the system model by an arbitrary excitation at the command input. In this study, a step perturbation was employed, which is simple to apply and leads to an intuitive interpretation of the output response. The effects of switching and quantisation noise have been overcome by choosing the sampling interval after the switching oscillations have decayed and by averaging the responses of synchronously perturbed sequences. The proposed method has been evaluated on Buck and Boost converters. The method was verified in two phases: Off-line - data acquisition procedure was implemented on a TMS320F2407-DSP and the identification calculations were carried out on a PC. On-line - The identification procedure (data acquisition plus fitting algorithm) was programmed on a TMS320F2808-DSP.

Novel Full-bridge ZVS DC-DC Converter with an Clamp Diodes

Abstract The two arms of this converter all work at zero-voltage switching condition, that bring many advantages, such as little loss of power, simple control, etc. But these also exists some problems, such as parasitic oscillation on the output rectifier diodes. A novel full-bridge ZVS PWM DC-DC converter which adopts two clamping diodes in the first side of the transformer is proposed to reduce the parasitic oscillation in this paper. In this paper, It heavily analyzes the realization process of their soft-switching and the reason of related issues and solution, we establishes simulation model and simulates using orCAD. Finally,a 5 kW ZVS PWM DC-DC converter Prototype in that TMS320F2812 is the core controlled chip has been set up, and the experiments showed us the validation of the correlative theory.

Deriving The Canonical Equivalent Circuit For Small Signal & Low Frequency Ac Model For The Sepic And Zeta PWM Dc-dc Converters With Two-port Network

PWM dc-dc converters operating in Continuous Conduction Mode (CCM) perform similar basic functions despite the topology of which one. The canonical equivalent circuit of small signal & low frequency ac model permits to analyze converter behavior in a general manner, without the need to make reference to a specific topology. For Buck, Boost, Buck-Boost and Cuk topologies the “plug-in” parameters of the canonical model can be easily found just by circuit manipulation using very simple circuit analysis techniques. For the Sepic (Single-Ended Primary Inductor Converter) and Zeta topologies, utilization of the same procedure fails and one cannot arrive to the canonical model. To overcome this barrier, some authors indicate the need to apply circuit synthesis techniques which are not always familiar to many engineers. It will be shown that it is possible to arrive to the canonical model of this two converter topologies by using the well-known two-port network (quadripoles) circuit analysis technique.

새로운 소용량 승압형 PWM 초퍼 회로의 특성

Actually, The hard switching high frequency PWM DC-DC converters are existing accompany, the high frequency of pulse modulation carrier frequency increase of switching loss of power semiconductor switching elements, there are have some problem points of EMI etc. This compliance with a voltage surge or the electric current surge are where the switching transient phenomenon accompanies. In order to solve like this problem effectively it described the principle of operation of New Small Scale Boost PWM Chopper circuits from the present paper, draw Characteristics from simulation and experiment.

Power converters and amplifiers (review of "Pulse-Width Modulated DC-DC Power Converters" by Kazimierczuk, M.K.; 2008) [Book News

This book is a comprehensive textbook in the areas of electrical, electronics, and telecommunications engineering. It consists of 17 chapters and two appendices. Some of the topics covered include: buck PWM DC-DC converters; boost PWM DC-DC converters; buck-boost-PWM DC-DC converters; half-bridge and full-bridge converters; push-pull PWM DC-DC converters; open-loop small-signal characteristics of boost converters for CCM; current-mode control of boost converters; silicon and silicon carbide power diodes; and soft-switching DC-DC converters. Appendix A is an introduction to SPICE and Appendix B provides an introduction to MATLAB. Answers to problems and the index are also included at the end of the book. The book is recommended for senior undergraduate and graduate students but also for practicing engineers working with switch-mode power supplies, within applications such as computers, telecommunications, industrial electronic systems, automobile electronics, medical equipment, radars, and aerospace power technology.

새로운 풀-브리지 소프트 스위칭 PWM 인버터를 이용한 용접기용 DC-DC 컨버터의 개발

본 연구에서는 일반적으로 용접기의 전원장치로 사용되어지는 풀-브리지 회로에 1개의 스위치와 1개의 무손실 스너버 부분 공진 커패시터로 구성된 간단한 액티브 보조 부분 공진 스너버를 추가한 새로운 풀-브리지 소프트 스위칭 PWM DC-DC 컨버터를 제안하였다. 제안한 풀-브리지 소프트 스위칭 DC-DC 컨버터 회로는 각 액티브 스위치에 인가된 전압이 DC 버스 라인 전압의 1/2로 되기 때문에 AC 400[V]계 상용전원 라인에 적용할 경우에도 600[V]내압의 스위칭 소자(IGBT)가 적용 가능하며, 기존 회로의 DC 버스 라인 스위치에 발생되는 도통 손실을 저감하여 고주파 변압기의 1차측의 전류가 2차측보다 작아지는 저 전압, 대전류 직류 출력을 얻어 수 있었다. 그리고 모든 영역에서 ZCS/ZVS 동작함으로써 저전압, 대전류 직류 출력의 스위칭 전원 장치에 있어 고주파, 고효율, 고출력을 실현할 수 있다. 이러한 모든 사항은 시뮬레이션과 실험 결과로부터 도출하였으며, 제안한 회로의 단점을 보완할 경우에는 차세대형 TIGㆍMIGㆍMAG 아크 용접기용 전원으로 용이할 것으로 판단된다.

Simulation of PWM DC-DC 4-Q converter driven S.E. DC motor

In this work, the authors propose a comprehensive mathematical model for PWM DC-DC converters with unipolar switching scheme (including all classes: A, B, C, D and four-quadrant E) and closed-loop PWM DC-DC converter driven DC S.E. motor for transportation drives. The model is useful for electric drives designers for the investigation of both normal and abnormal modes of operation of the drive.

Averaged modelling of switched-inductor cells considering conduction losses in discontinuous mode

Many PWM DC-DC converters contain a switched-inductor cell for which an average-value model is required. However, the presence of parasitics associated with the cell's components complicates the development of accurate averaged models, especially for the discontinuous conduction mode. Here is described an improved full-order, large-signal averaged switching cell. The proposed averaged cell takes into account conduction losses as required by the energy conservation principle and provides a more accurate duty-ratio constraint. The final model shows improvement over several previously established averaged cells in predicting large-signal, time-domain transients as well as small-signal, frequency-domain characteristics

3[kW]급 연료전지용 전력변환장치의 개발

최근 저전압ㆍ대전류 출력 특성을 갖는 연료전지를 위한 새로운 발전시스템으로 주목받고 있다. 연료전지 발전시스템에서는 DC-DC 승압용 컨버터와 DC-AC 인버터가 필요하다. 그러므로 본 논문에서는 연료전지의 전압을 380[V<SUB>DC</SUB>]로 승압하기 위한 절연형 DC-DC 컨버터와 단상 220[V<SUB>AC</SUB>]로 변환하기 위한 LC필터를 가진 PWM 인버터로 구성된 전력변환장치를 제안하였다. 특히 제안한 고주파 절연형 ZVZCS PWM DC-DC 컨버터는 환류 다이오드를 포함한 탭부 인덕터 필터를 이용하여 순환 전류를 저감시켰으며, 스위치 및 변압기의 턴-온, 턴-오프시에 오버슈트 전압이나 과도현상이 발생하지 않는다. 그리고 넓은 출력 전압 조정에도 효율을 93~97[%]정도 얻을 수 있으며, 출력 부하전류의 변화에 대해 거의 일정한 출력 전압 특성을 가졌다.

Computer Aided Control Optimization of Power Converters

The paper describes an improved automatic technique for the dynamic modelling of PWM DC-DC converters. It makes easier and more accurate the control optimization. Since the operating ranges of the load current and of the input voltage are generally wide, the usual recourse to a single linear model provides an information inadequate, in many cases. Such insufficiency is heavy when different operating modes are involved, f.i. DCM/CCM, whose dynamic performances can be very dissimilar. The proposed technique makes reference to a full set of models in the ranges of the input variables. Automatic modelling in the state space discrete time, by means of suitable software tools, cuts the drawback of implementing a large number of models. It gets the full set of the dynamic descriptions in a short time and provides a bundle of frequency responses as shown in the Fig. 1s.The case of a phase-shift controlled PWM converter is studied. The open loop frequency responses are provided first, with indications for the feedback optimization. After assigning the feedback compensation networks the closed loop behaviour over the whole operating range is shown. The compliance of the model forecasts with the real life is very good.

A Three-Phase ZVS PWM DC-DC Converter Associated With a Double-Wye Connected Rectifier, Delta Primary

This paper presents the theoretical analysis of the three-phase zero voltage switching pulsewidth modulation dc-dc converter associated with a double Wye connected rectifier, delta primary, using a special switching scheme in order to maintain equilibrium among the currents through the output filters. The operating stages are described and the simulation and experimental results of a 6-kW prototype are presented

Numerical state-space average-value modeling of PWM DC-DC converters operating in DCM and CCM

State-space average-value modeling of pulsewidth modulation converters in continuous and discontinuous modes has received significant attention in the literature, and various models have been developed. This paper presents a new approach for generating the state-space average-value model. In the proposed methodology, the so-called duty-ratio constraint and the correction term are extracted numerically using the detailed simulation and are expressed as nonlinear functions of the duty cycle and average-value of the fast state variable. The parasitic effects of circuit elements are readily included. The resulting average-value model is compared to a hardware prototype, a detailed simulation, and several previously published models. The proposed model is shown to be very accurate in predicting the large-signal time-domain transients as well as the small-signal frequency-domain characteristics.

Realization of parasitics in state-space average-value modeling of PWM DC-DC converters

Analytical average-value modeling of pulsewidth modulation dc–dc converters is usually based on the piece-wise linear waveforms of the circuit variables and neglects the parasitics that give rise to waveform nonlinearities and complicate model derivation. This letter presents a straightforward but powerful methodology that considers the true averaging of nonlinear waveforms and produces a fairly accurate large-signal transient model that is functional in both operational modes. Based on the proposed modeling approach, a fast procedure for extracting the small-signal frequency-domain characteristics is set forth. The key model parameters are established numerically using the detailed simulation, which streamlines the analysis. The resulting average-value model is validated with a hardware prototype, a detailed simulation, and several previously established models in time and frequency domains.

새로운 고주파 절전형 소프트 스위칭 PWM DC-DC 컨버터의 토폴로지

A novel high frequency insulated soft switching PWM DC-DC converter circuit is proposed and then it is achieved the high-efficiency. This converter does not use the o(citing current of a high frequency transformer but use inductance. Then it realizes a widely stable zero voltage switching operation with the use of a novel ON-OFF control method at synchronized rectification power MOSEFETs of the high frequency insulated transformer secondary. Therefore, it is brought over 97[%] measurement efficiency by proposed DC-DC converter.