Regenerative Snubber Research Articles

Smart irrigation system with GSM module using DC-DC converter with Regenerative Snubber

Smart irrigation system with GSM module using DC-DC converter with Regenerative Snubber

Single-Switch Coupled-Inductor-Based Two-Channel LED Driver With a Passive Regenerative Snubber

In this paper, a single-switch coupled-inductor-based two-channel light-emitting diode (LED) driver with a passive regenerative snubber is presented. In the proposed LED driver, the energy-transferring capacitor is not only used to step up the voltage gain but also to achieve the current balance among LED strings. Moreover, a passive regenerative snubber is added not only to recycle the leakage inductance energy but also to improve the voltage gain. As compared with the prior work, only one switch is required. Thus, the configuration of the proposed LED driver is simpler. Since the proposed LED driver has a higher voltage gain than the prior work, the turns ratio of the proposed LED driver can be lower. Thus, the magnetic core size can be reduced. In addition, both LED drivers have the same component count. Finally, the operating principle, analysis, and experimental results are provided to verify the effectiveness of the proposed LED driver.

Passive Regenerative and Dissipative Snubber Cells for Isolated SEPIC Converters: Analysis, Design, and Comparison

An isolated converter such as SEPIC has high voltage stress on the main switch due to transformer leakage inductance. To solve this issue, active or passive clamp action is necessary. The common passive solution based on an RCD snubber is simple but impractical when the value of the leakage inductance is significant. On the other hand, passive regenerative solutions generally compromise the isolation, making the search for a suitable snubber a challenge. In this paper, an effective passive regenerative snubber cell for isolated SEPIC converters operating in DCM or CCM is presented. It is intended to improve the converter efficiency by transferring the energy stored in the transformer leakage inductance to the output. The analysis is presented in detail for DCM and extended to CCM together with a practical design procedure. In order to compare with the RCD, the analysis and design of a conventional cell are presented as well. To validate the proposal and quantify its feasibility, experimental results are performed for both dissipative and regenerative snubbers on a 100 W, 100 V, input and 50 V output voltage converter operating first in DCM and later in CCM.

High Step-Up Trans-Inverse (Tx−1) DC–DC Converter for the Distributed Generation System

This paper introduces a new magnetically coupled single-switch nonisolated dc–dc converter with a high-voltage gain. The topology utilizes magnetic coupling for boosting its output voltage, but unlike other converters with coupled magnetics, its voltage gain is increased by reducing its magnetic turns ratio. The name “Trans-inverse (Tx−1)” is thus used for representing this inverse operating principle of the converter. The converter draws a continuous current from the source and is, hence, suitable for many types of renewable sources. Its leakage energy from the coupled magnetics has further been recycled and transferred to the load by an integrated regenerative snubber circuit. Its inclusion of dc-current-blocking capacitors has also helped to prevent core saturation, which, together with other performance features, has been verified experimentally.

Dimmable flicker‐free power LEDs lighting system based on a SEPIC rectifier using a regenerative snubber

This study presents a universal-input AC electronic lighting system using a non-isolated SEPIC PFC rectifier to drive and control power light emitting diodes (LEDs). One energy regenerative snubber is proposed to reduce the converter switching losses aiming to improve the overall system efficiency. A linear current regulator is employed to provide the features of flicker-free and dimming capability for the lighting system. The operation stages as well as the theoretical waveforms and main equations at steady state of the proposed SEPIC rectifier using the regenerative snubber are described in details. To reduce the efficiency impairment, the conditions for achieving minimum energy loss in the current regulator are also detailed. A control loop designed using the results from the small-signal analysis presented in the study is proposed to track the optimal current regulator operating point in real-time. Experimental results of a prototype operating from 90 to 265 V and output power from 15 to 100% for 35 LEDs / 42 W are presented to verify the analyses carried out.

Investigation of High gain MIC power converter for multicrystal PV module employing fuzzy logic technique

A Mutual Inductive Coupled (MIC) DC-DC power converter circuit for Photo-Voltaic (PV) system employing fuzzy logic based maximum power point tracking is presented in this research paper. The proposed DC-DC converter has been modelled and simulated using Matlab-simulink environment for obtaining high gain. The mutually coupled inductor uses one core instead of two or more, which reduces size of the converter. A passive regenerative snubber is exploited for absorbing the energy of stray inductance and also the capacitors are charged in parallel and discharged in series through the mutual coupled inductor for achieving high voltage gain of this converter. The voltage gain characteristics of the MIC converter have been studied for various coupling coefficient, turns ratio of two-winding mutual inductor and duty cycle. Moreover, PV system is conveniently interfaced with proposed power converter for maximizing the solar energy yield and analysed by employing Perturb & Observe (P&O) and fuzzy logic based MPPT algorithms under various operating conditions. The obtained results reveal that, the fuzzy controller provides good improvement in tracking of maximum power and helps to extract considerable amount of additional solar energy from a PV module as compared with P&O algorithm.

A New Single-Switch Isolated High-Gain Hybrid Boosting Converter

A new single-switch isolated hybrid boosting converter featuring low-component stress, simple control, high efficiency, high power density, and flexible gain extension is proposed in this paper. At the primary side, a new design of energy regenerative snubber is proposed to provide soft-switching condition, suppress voltage spike, and recycle leakage energy. At secondary side, a bipolar voltage multiplier (BVM) structure which enhances the gain boosting capacity, reduces the output ripple, and facilitates fly-back-forward operation of transformer is proposed. Based on this structure, the transformer can deliver energy to the output at both magnetizing and magnetic resetting stages. In addition, the bulky high-voltage-rated output filter capacitor can be eliminated due to the cascaded and autobalanced capacitors in the BVM structure. A 200-W 35- to 400-V prototype is built to demonstrate the feasibility of the proposed topology. The peak efficiency of 93.8% is reached and 91.2% is achieved at rated power.

Steep-Gain Bidirectional Converter With a Regenerative Snubber

This paper introduces a SEPIC-derived bidirectional dc–dc converter. The proposed converter utilizes tapped inductor and charge pump techniques to achieve steep voltage conversion ratio and an active lossless regenerative snubber to attain lossless switching and high efficiency. The paper presents the principle of operation, steady-state analyses, and experimental results obtained from a 400-W, 48-V/380-V prototype. The efficiency of the proposed topology is demonstrated to peak at 96.4% for boost mode and 95.0% for buck mode.

Analysis and Design of Charge Pump-Assisted High Step-Up Tapped Inductor SEPIC Converter With an “Inductorless” Regenerative Snubber

This paper introduces a SEPIC-derived converter suited for alternative energy generation applications. The proposed converter utilizes tapped inductor and charge pump techniques to achieve high step-up gain and a passive regenerative snubber to attain high efficiency. Compared with earlier counterparts, the proposed converter has the advantage of continuous input current, which can be helpful in attaining accurate tracking of maximum power point of solar panels. The paper presents principle of operation, theoretical analysis, and design guidelines. Theoretical expectations were confirmed by simulation and experimental results.

Analysis and Design of Energy Regenerative Snubber for Transformer Isolated Converters

An energy regenerative passive snubber for transformer isolated converters is proposed. The snubber is implemented on the transformer's primary and secondary windings. The proposed snubber significantly reduces the voltage spike across the switch caused by the transformer's primary inductance upon switch turn-off and facilitates the fast ramping up of the transformer secondary current. In addition, the proposed snubber provides lossless zero voltage turn off and zero current turn on conditions for the power switch. Experimental example of a flyback converter has shown measured efficiency exceeding 90%. This paper describes the principle of operation and presents approximate theoretical analysis and design guidelines of the proposed snubber. Simulation and experimental results are also reported. The proposed energy regenerating snubber is best suited for flyback and SEPIC converters and can also be adapted to other transformer isolated topologies.

Derivation of a family of high step‐up tapped inductor SEPIC converters

A family of single-switch SEPIC-derived converters, which apply a tapped inductor (TI), a charge pump (CP) and an inductorless regenerative snubber to attain a high DC step-up at high efficiency is introduced. The proposed converter family has the advantage of continuous input current, which can be helpful in attaining accurate tracking of the maximum power point of solar panels. The feasibility of the proposed topology is verified by simulation and experimental results.

An Efficient Single-Switch Quasi-Active PFC Converter With Continuous Input Current and Low DC-Bus Voltage Stress

This paper proposes a novel single-switch quasi-active power factor correction (PFC) converter based on two flyback dc/dc modules. To achieve a high efficiency, part of the input power is directly transferred to the load by the first dc/dc module. The rest of the input power is stored in the dc-bus capacitor and reprocessed by the second dc/dc module. Together, the dc-bus capacitor and the second dc/dc module also serve as a regenerative snubber. Furthermore, a quasi-active PFC circuit is provided to improve the power factor and to ensure the continuous current mode (CCM) operation of the input inductor without the need for sophisticated feedforward sensing and control mechanism. The quasi-active PFC circuit is driven by a magnetic switch, through the tertiary winding of the transformer of the first flyback module. The input current harmonics of the proposed converter meet the IEC 61000-3-2 (Classes A, C, and D) requirements. The dc-bus capacitor voltage is always less than the input voltage regardless of the load condition and is fairly invariant to large variations of the input voltages. High power factor with CCM operation and fast output voltage regulation have been achieved through a single-loop controller. Operating principles, analysis, and experimental results are presented to verify the effectiveness of the proposed converter.

A High Efficiency DC-DC Boost Converter with Passive Regenerative Snubber

This paper describes the improvement in converter efficiency by reducing the switching loss and by recovering the snubber stored energy. A capacitive based passive regenerative snubber circuit is modeled for a dc-dc boost converter. The proposed snubber is mainly used to reduce the turn-off loss of the main switch. The energy recovery process and the turn-off loss depends on the size of the snubber capacitance; therefore, the conventional and the proposed converters are designed for high and low input voltage conditions with different sizes of the snubber capacitance. Based on the results obtained, the snubber capacitors are classified as small, normal and large snubbers. The Matlab simulation results obtained are presented.

State-Plane Analysis of Regenerative Snubber for Flyback Converters

The flyback converter is a popular topology for implementing low power and multiple output power supplies. However, the high leakage inductance of the flyback transformer causes high voltage spikes that can damage the main transistor when the switch is turned OFF. Therefore, a turn-off snubber is needed to limit the peak voltage stress. This paper presents the analysis of an energy regenerative snubber using the graphical state-plane technique. The undertaken approach yields a clear-cut design procedure for minimum switch voltage stress. Experimental evaluation of the energy regenerative snubber in comparison with other common snubbers shows that under the same voltage stress the efficiency of energy regenerative snubber has 8% improvement on average over an RCD snubber and 2% improvement over the nondissipative LC snubber.

Intelligent Photovoltaic Maximum Power Point Tracking Controller for Energy Enhancement in Renewable Energy System

Photovoltaic (PV) system is one of the promising renewable energy technologies. Although the energy conversion efficiency of the system is still low, but it has the advantage that the operating cost is free, very low maintenance and pollution-free. Maximum power point tracking (MPPT) is a significant part of PV systems. This paper presents a novel intelligent MPPT controller for PV systems. For the MPPT algorithm, an optimized fuzzy logic controller (FLC) using the Hopfield neural network is proposed. It utilizes an automatically tuned FLC membership function instead of the trial-and-error approach. The MPPT algorithm is implemented in a new variant of coupled inductor soft switching boost converter with high voltage gain to increase the converter output from the PV panel. The applied switching technique, which includes passive and active regenerative snubber circuits, reduces the insulated gate bipolar transistor switching losses. The proposed MPPT algorithm is implemented using the dSPACE DS1104 platform software on a DS1104 board controller. The prototype MPPT controller is tested using an agilent solar array simulator together with a 3 kW real PV panel. Experimental test results show that the proposed boost converter produces higher output voltages and gives better efficiency (90%) than the conventional boost converter with an RCD snubber, which gives 81% efficiency. The prototype MPPT controller is also found to be capable of tracking power from the 3 kW PV array about 2.4 times more than that without using the MPPT controller.

Analysis, Design, Modeling, and Implementation of an Active Clamp HF Link Converter

This paper deals with the system oriented analysis, design, modeling, and implementation of active clamp HF link three phase converter. The main advantage of the topology is reduced size, weight, and cost of the isolation transformer. However, violation of basic power conversion rules due to presence of the leakage inductance in the HF transformer causes over voltage stresses across the cycloconverter devices. It makes use of the snubber circuit necessary in such topologies. The conventional RCD snubbers are dissipative in nature and hence inefficient. The efficiency of the system is greatly improved by using regenerative snubber or active clamp circuit. It consists of an active switching device with an anti-parallel diode and one capacitor to absorb the energy stored in the leakage inductance of the isolation transformer and to regenerate the same without affecting circuit performance. The turn on instant and duration of the active device are selected such that it requires simple commutation requirements. The time domain expressions for circuit dynamics, design criteria of the snubber capacitor with two conflicting constrains (over voltage stress across the devices and the resonating current duration), the simulation results based on generalized circuit model and the experimental results based on laboratory prototype are presented.

Bidirectional high-frequency link inverter with regenerative snubber and deadbeat control

This article presents a bidirectional high frequency transformer link inverter with reduced power switches. On the secondary side of the transformer, two switches are used for rectification and four switches are used for the unfolding stage. The latter are switched at low frequency (50 Hz). Furthermore, a regenerative snubber is incorporated to reduce the voltage surge due to the leakage inductance of the transformer's secondary. The proposed inverter is controlled by a deadbeat controller, which consists of the inner current loop, outer voltage loop and a feed forward controller. Additional disturbance decoupling networks are employed to improve the system robustness towards load variations. A 1-kVA prototype inverter is constructed and the deadbeat control algorithm is experimentally verified. The experimental results show that the inverter has high efficiency (86–94%) with low steady-state output voltage total harmonics distortion (1.5%).

A Novel Capacitor-Switched Regenerative Snubber for DC/DC Boost Converters

Advanced transportation technologies, such as hybrid-electric, battery-electric, and hybrid-fuel-cell vehicles, rely on high-power dc/dc converters to interconnect and manage their power sources. Boost converters are particularly useful in stepping up the voltage from a battery or fuel cell to match the traction motor operating voltage range. High-frequency high-efficiency operation is crucial so that the sizes of the passive components can be reduced and fuel economy can be improved. This paper proposes a new regenerative-snubber circuit that greatly reduces the switching losses of the insulated-gate bipolar transistor in the boost converter, so that high-switching-frequency operation can be achieved. The circuit uses no additional magnetic components, enjoys a simple control strategy, and results in very high efficiency while significantly reducing the mass of the converter. Two 5-kW boost converter prototypes, i.e., one with and the other without the regenerative snubber, have been built and tested to evaluate and demonstrate the impact of the proposed snubber circuit.

Analysis and Design of Forward Converter With Energy Regenerative Snubber

An energy regenerating snubber for a forward converter is presented. The proposed snubber uses a tertiary transformer winding and beneficially exploits transformers' leakage inductances. The proposed snubber is capable of resetting the transformer, as well as eliminating leakage inductance voltage spike across the power switch. The proposed snubber recycles the recovered energy partially to the load and partially back to the source. This paper presents theoretical analysis, simulation and experimental results.

A Modified SEPIC Converter for High-Power-Factor Rectifier and Universal Input Voltage Applications

A high-power-factor rectifier suitable for universal line base on a modified version of the single-ended primary inductance converter (SEPIC) is presented in this paper. The voltage multiplier technique is applied to the classical SEPIC circuit, obtaining new operation characteristics as low-switch-voltage operation and high static gain at low line voltage. The new configuration also allows the reduction of the losses associated to the diode reverse recovery current, and soft commutation is obtained with a simple regenerative snubber circuit. The operation analysis, design procedure, and experimental results obtained from a 650-W universal line power-factor-correction prototype of the proposed converter are presented. The theoretical analysis and experimental results obtained with the proposed structure are compared with the classical boost topology.