SINGLE-STAGE SINGLE-SWITCHED RECTIFIER/REGULATOR WITH MAGNETIC COUPLED NONDISSIPATIVE SNUBBER

2004 ◽  
Vol 13 (03) ◽  
pp. 557-576
Author(s):  
CHUNG-WOOK ROH ◽  
GUN-WOO MOON ◽  
MYUNG-JOONG YOUN

This paper presents a new single-stage single-switched forward converter with magnetic coupled nondissipative snubber, which gives good power factor correction (PFC), low current harmonic distortion, and tight output voltage regulation. The proposed converter features low switch current and voltage stresses, essential for the design of a single-stage power factor correction converter. The prototype shows that the IEC1000-3-2 requirements are met satisfactorily with nearly unity power factor. This proposed converter with magnetic coupled nondissipative snubber is particularly suited for power supply applications with low power level.

Author(s):  
S. T. Siddharthan ◽  
Andrew Jones ◽  
S. Kathikeyan

This paper deals with PFC-isolated Zeta converter fed LED drive to overcome the power factor problems. The proposed circuit topology consists of diode bridge rectifier and isolated Zeta converter with high frequency transformer. A single –phase supply is used to feed a DBR followed by a filter to avoid any switching ripple in DBR and the supply system. An isolated Zeta converter is operated to work under DCM mode. This combination of DBR and PFC converter is used to feed a LED drive. This converter is simulated in MATLAB platform. This converter provides better results such as unity power factor and less current harmonic distortion.


Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1340
Author(s):  
Yih-Her Yan ◽  
Hung-Liang Cheng ◽  
Chun-An Cheng ◽  
Yong-Nong Chang ◽  
Zong-Xun Wu

A novel single-switch single-stage high power factor LED driver is proposed by integrating a flyback converter, a buck–boost converter and a current balance circuit. Only an active switch and a corresponding control circuit are used. The LED power can be adjusted by the control scheme of pulse–width modulation (PWM). The flyback converter performs the function of power factor correction (PFC), which is operated at discontinuous-current mode (DCM) to achieve unity power factor and low total current harmonic distortion (THDi). The buck–boost converter regulates the dc-link voltage to obtain smooth dc voltage for the LED. The current–balance circuit applies the principle of ampere-second balance of capacitors to obtain equal current in each LED string. The steady-state analyses for different operation modes is provided, and the mathematical equations for designing component parameters are conducted. Finally, a 90-W prototype circuit with three LED strings was built and tested. Experimental results show that the current in each LED string is indeed consistent. High power factor and low THDi can be achieved. LED power is regulated from 100% to 25% rated power. Satisfactory performance has proved the feasibility of this circuit.


Author(s):  
Saravanan D ◽  
Gopinath M

In recent decades, several research works have been focused on the efficient Power Factor Correction (PFC) converter design in to meet the power supply efficiency. Conventional PFC cuk converter widely uses the full bridge rectifier which had resulted in overall increase of converter losses and inefficiency. This paper is intended to develop a novel PFC Bridgeless cuk converter for LED lamp applications. In this work, the limitations of the conventional PFC Cuk converter are resolved. The major contributions of the proposed work include the minimization in the number of conduction devices and minimization of the power utility devices which in turn resulted in minimal losses and better efficiency. Moreover, the proposed converter works in DCM which requires only one voltage sensor which results in reduced cost. The proposed Modified BL Cuk converter (MBL-CUK) for LED lamp is simulated in MATLAB and the corresponding results show the better power quality indices such as power factor and Total Harmonic Distortion.


Author(s):  
V Divyasri Sudharani and K Sabarinath

Nowadays the use of electronic equipment finds a progressive development in the modern world. Hence it becomes a mandate to check whether the harmonic content of line current of any electronic device which is connected to the ac supply meets the appropriate standards. This demand is satisfied by implementing the Power Factor Correction (PFC) circuit in order to make the input current to be in sinusoidal in nature and in-phase with the input voltage. Numerous solutions are available to make the line current almost sinusoidal. This paper describes an isolated power factor corrected power supply that utilizes the leakage inductance of the isolation transformer to provide boost inductor functionality. The bulk capacitor is in the isolated part of the power supply allowing for controlled startup without dedicated surge limiting components. A control method based on switch timing and input/output voltage measurements is developed to jointly achieve voltage regulation and input power factor control.


Author(s):  
Bindu K V ◽  
B Justus Rabi

In this paper, the disturbances in power system due to low quality of power are discussed and a current injection method to maintain the sinusoidal input current which will reduce the total current harmonic distortion (THD) as well as improve the power factor nearer to unity is proposed. The proposed method makes use of a novel controlled diode rectifier which involves the use of bidirectional switches across the front-end rectifier and the operation of the converter is fully analyzed. The main feature of the topology is low cost, small size, high efficiency and simplicity, and is excellent for retrofitting front-end rectifier of existing ac drives, UPS etc. A novel strategy implementing reference compensation current depending on the load harmonics and a control algorithm for three-phase three-level unity PF rectifier which draws high quality sinusoidal supply currents and maintains good dc link- voltage regulation under wide load variation. The proposed technique can be applied as a retrofit to a variety of existing thyristor converters which uses three bidirectional switches operating at low frequency and a half-bridge inverter operating at high frequency .The total power delivered to the load is processed by the injection network, the proposed converter offers high efficiency and not only high power factor but also the Total Harmonic Distortion is reduced. Theoretical analysis is verified by digital simulation and a hardware proto type module is implemented in order to confirm the feasibility of the proposed system. This scheme in general is suitable for the common variable medium-to high-power level DC load applications.


Inventions ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. 70
Author(s):  
Jianming Xu ◽  
Bo Qian ◽  
Muhammad Humayun

In order to improve the power factor and reduce the input current harmonics, power factor correction (PFC) converters are utilized. This paper introduces a single-stage continuous conduction mode (CCM) soft-switched power factor correction (PFC) converter with a tandem topology. The proposed topology has two operating modes, namely resonant operation mode and boost operation mode. Such a design and control realizes the zero-voltage switching (ZVS) and zero current switching (ZCS) of the power switches. The proposed topology has been introduced to reduce the total harmonic distortion (THD) of the input current further in the boost PFC converter under lower power and higher output voltage conditions. The simulation and experimental results are presented to verify the effectiveness of the performance of the proposed design and its control.


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