Active Clamp Research Articles

A Control Strategy for Reducing Voltage Ripples in Series-Connected SiC MOSFETs Using Active Clamping Modules in High Power VSCs

A Control Strategy for Reducing Voltage Ripples in Series-Connected SiC MOSFETs Using Active Clamping Modules in High Power VSCs

Design and Performance Evaluation of Multilevel Inverter for Solar Energy Systems and Electric Vehicle Charging with Multi Output Active Clamp Forward Converter

Design and Performance Evaluation of Multilevel Inverter for Solar Energy Systems and Electric Vehicle Charging with Multi Output Active Clamp Forward Converter

Reverse power transmission of two-transformer active clamp forward flyback converter

Reverse power transmission of two-transformer active clamp forward flyback converter

A bidirectional isolated DC‐DC converter with low voltage stresses for energy storage systems integration

AbstractHerein, a bidirectional isolated DC‐DC converter with low voltage stress is introduced to utilise in energy storage frameworks. Two sets of coupled inductors (CI) and a transformer are utilized on the low‐voltage side to increase voltage gain. Through the series connection of the secondary windings of the CIs with the primary windings of the transformer, the concluded voltage gain is improved by the multiplication of the turns ratios of CI and transformer. As a result, the voltage gains as well as the voltage stresses in both directions can be flexibly improved through three degrees of freedom, which are the turns ratios of the CIs, transformer and duty cycle. Clamp capacitors accomplish active clamping, and the energy saved within the leakage inductance is recycled. Additionally, some switches are performed with soft‐switching and partially diminished switching losses. The steady‐state analysis and extensive performance comparison of the proposed converter prove that the proposed converter outperforms the similar previous converters in the state‐of‐the‐art. An 800 W 48 V/380 V prototype is developed to prove the performance of the proposed converter. The peak efficiency amounts of the proposed system in the high step‐down and high step‐up modes are 95.8% and 96.2%, respectively.

A Chua’s Chaotic Chirp Spread-Spectrum Power Spectral Homogenization Strategy Based on Distribution Transformation

When utilizing high-dimensional chaotic signals for frequency modulation, achieving a uniformly distributed power spectrum is a challenging task. This paper addresses this challenge by proposing a power spectrum homogenization strategy based on distribution transformation. The strategy transforms the task of achieving a uniformly distributed power spectrum in frequency modulation of high-dimensional chaotic signals to solve and equalize the probability density function of the chaotic signals, thereby further enhancing the ability of high-dimensional chaotic signals to suppress electromagnetic interference. Firstly, the difficulty of obtaining a smooth probability density function of chaotic modulation signals is solved using the kernel density estimation algorithm. Then, a distribution transformation algorithm is proposed to convert non-uniformly distributed chaotic modulation signals into uniformly distributed chaotic modulation signals. By using uniformly distributed chaotic modulation signals for frequency modulation, the objective of power spectrum equalization is achieved. Finally, taking the Chua’s chaotic signal as an example, the effectiveness of the proposed strategy is verified using an experimental platform based on a digital signal processor-controlled active clamping flyback converter.

An isolated bidirectional interleaved converter with coupled inductors and active clamp for energy storage systems

An isolated bidirectional interleaved converter with coupled inductors and active clamp for energy storage systems

Smart Home Powered by Solar: IoT-based SEPIC Converter Control

Background: In this article, an IOT solution for managing and controlling a PV system with applications for the home is presented. A DC-DC SEPIC converter, a bidirectional converter, a PWM generator, and a single-phase voltage source inverter with active clamping are used for power conditioning. An output voltage control loop is implemented, and real-time online communication with an internet server is accomplished using the PIC microcontroller. Methods: The ESP8266MOD WIFI IOT module works with the Blynk mobile app. Experimental findings showing the proper operation of IOT features demonstrate the effectiveness of voltage regulation. In this article, frequency is taken into consideration as solar power is integrated with the grid. A user may easily control the DC-DC converter, load batteries, and monitor battery voltage through our userfriendly GUI interface. Results: In this paper, an IOT (Internet of Things) application was used to control and track the output of a modest PV power plant. The study shows the efficiency of the digitally controlled system developed to regulate the output voltage of the SEPIC DC-DC converter. Practical Significance: They further argue that the ESP8266 and microcontroller's versatility make them an appropriate instrument for remote and real-time monitoring and control of the proposed model from around the world. The energy that is produced by the sun is added to the grid so that it may be put to effective use and contribute to satisfying the rising demand for energy. Solar energy is the input that SEPIC uses to charge the batteries and for all of its other processes. In the event that solar photovoltaic (PV) panels are not available, the SEPIC DC-DC converter will derive its energy from AC power. Conclusion: In this article, an IOT (Internet of Things) application was used to control and track the output of a modest PV power plant. The research demonstrates the effectiveness of the digitally controlled system created to manage the output voltage of the SEPIC DC-DC converter. They further argue that the ESP8266 and microcontroller's versatility make them an appropriate instrument for allowing remote and real-time monitoring and control of the proposed model from any part of the world. The energy that is produced by the sun is added to the grid so that it may be put to effective use and contribute to satisfying the rising demand for energy. Solar energy is the input that SEPIC uses to charge the batteries and for all of its other processes. In the event that solar photovoltaic (PV) panels are not available, the SEPIC DC-DC converter will derive its energy from AC power.

A Study of High Gain DC-DC Boost Converters for Renewable Energy Sources

This paper presents a comprehensive investigation into the various topologies of DC-DC boost converters which are designed for optimal integration with RES like photovoltaic (PV) systems. Photovoltaic applications demand efficient energy harvesting and management to maximize the conversion of solar energy into electrical power. The DC-DC topologies include switched coupled inductor, basic coupled inductor, coupled capacitor with coupled inductor with a snubber circuit, active clamp, high step-up and three-winding dual switches are considered for study. Each topology is analyzed in terms of its suitability for PV applications, considering factors such as efficiency, voltage gain, and reliability. The basic coupled inductor topology is explored as a reference point, providing a foundation for understanding the subsequent advanced configurations. This work explores and compares several prominent boost converter configurations, incorporating advanced techniques to enhance overall performance and efficiency for RES applications.

Dual-Coupled-Inductor-Based High-Step-Up Boost Converter with Active-Clamping and Zero-Voltage Switching

Many applications, such as photovoltaic systems, uninterruptible power supplies, and automobile headlamps, need a high step-up DC–DC converter without isolation. The conventional boost converter has the advantages of simple topology and easy control. However, it has some shortcomings, such as insufficient step-up voltage ratio and poor efficiency when operating at large duty-cycle conditions. One of the popular topologies used to overcome these problems is the coupled-inductor boost converter. It utilizes the turn ratio of the coupled inductor to realize a higher step-up voltage ratio. The drawback is that the leakage inductance of the coupled inductor causes a huge voltage spike when the power switches are turned off. Moreover, because coupled inductors are characterized by their large volume and high profile, a conventional coupled-inductor boost converter is unsuited for photovoltaic systems, such as the solar microinverter. This study proposes a novel high-step-up boost converter to solve these problems. This proposed converter uses dual coupled inductors instead of the conventional coupled-inductor boost converter. The secondary side of the coupled inductor is connected in series to increase the step-up voltage ratio. The proposed converter utilizes active clamping to achieve zero-voltage switching (ZVS) for suppressing voltage spike and improving conversion efficiency. In addition, low-profile designs can be fulfilled easily for solar microinverters. The proposed converter and its control method are introduced. The operation principle, circuit characteristics, and circuit analysis are presented. A prototype converter with 300 W output power 25–40 VDC input voltage and 200 VDC output voltage was tested. All functions, including high step-up voltage ratio, ZVS, and active clamping, were achieved, and the highest efficiency was around at 94.7%.

Design of 30 A Load Current and 93% Peak Efficiency for Active Clamping Forward Converter With Complete Protection

Design of 30 A Load Current and 93% Peak Efficiency for Active Clamping Forward Converter With Complete Protection

Resonant Gate Drive Circuit with Active Clamping to Increase Efficiency and Reliability

In power converters with high switching frequency, drive losses constitute a significant portion of the overall power losses. Resonant gate drivers can reduce drive losses, thereby enhancing the efficiency. However, resonant drivers suffer certain challenges: parameter drifts lead to the mismatch between the resonant frequency and the control frequency, and this mismatch can cause gate-to-source voltage overshoot. Moreover, the resonant driver is susceptible to external interference. This paper proposes a resonant circuit structure and control timing scheme aimed at overcoming these limitations. By incorporating a half-bridge clamp circuit, the proposed design achieves voltage clamping, thereby insulating the system from disturbances caused by mains power fluctuations. When there is a mismatch in resonant frequencies, the strategy employs a combination of hardware circuit diodes and control system timing to prevent overvoltage issues. Additionally, the utilization of MOSFETs minimizes the loss caused by prolonged current flow through body diodes, further reducing the resonant driving losses. Simulations have demonstrated the system’s stability under varying resonant parameters and its effective anti-interference capabilities in voltage clamping. Experiments achieved a power saving of 83.3% at a 1 MHz operating frequency. Both simulations and experimental validations confirm the feasibility of the proposed solution, its effectiveness in interference suppression, handling of resonant mismatches, and its role in further augmenting power conservation.

ZVS Active Clamp 포워드 컨버터를 적용한 철도차량용 전원공급장치

ZVS Active Clamp 포워드 컨버터를 적용한 철도차량용 전원공급장치

A High-Efficiency Integrated Converter for LED Driver

Enhancing the efficiency in the light-emitting-diode (LED) drivers is a noteworthy issue as it not only helps saving energy but also causes the long life span of the drivers. In this paper, a new LED driver with improved efficiency is proposed. Efficiency improvement is achieved without using any active or passive component to perform soft switching conditions. In the proposed driver, buck and buck-boost converters are integrated. The freewheeling diodes and inductors - of the two converters - are replaced by one diode and one inductor. So, the proposed driver constitutes a single-stage driver with a simple structure that uses only one controlled switch, one freewheeling diode, and one inductor. Besides its simple structure, the driver works with a constant frequency, which leads to using a simple controller. Efficiency improvement is obtained by changing the inductor size and LEDs arrangement rather than using the active clamp or snubber circuits. To decrease the switching losses in the proposed driver, the average of the input current is kept constant while the peak of the pulsating input current - which passes from the switch and freewheeling diode - is decreased. Moreover, power losses of the semiconductor components in the proposed driver are investigated, and consequently decreased, leading to improvement in the system's overall efficiency. Finally, a 10 W experimental driver is built and tested. The experimental results are consistent with theoretical analysis.

Wide range hybrid boost DC-DC converter with active clamp for fuel cell applications

Wide range hybrid boost DC-DC converter with active clamp for fuel cell applications

Dynamic Neural-Based Model Predictive Voltage Controller for an Interleaved Boost Converter With Adaptive Constraint Tuning

in recent years, interleaved current-fed boost dc converters consisting of a voltage multiplier and an active clamp circuit have been interested because of their good features like low input currents, and output voltages ripple high voltage-gains. Then developing more effective modeling and control techniques is important to increase their performance. In modeling section, it has been tried to estimate system model using the real data and dynamic neural networks with reducing number of variables. In control section there are constraints on control signal and its changing rate and in the proposed dynamic neural-based model predictive control (NMPC) controller, control signal changes constraint has been calculated adaptively. The proposed NMPC has been applied on system in online form and experimental results have been compared to the basic NMPC and a PI controllers. The output voltage have been specified for two loads with different input voltage. The experimental results show that their current transient response has smaller current peak and output voltage has smaller overshoot when load and voltage change. Output voltage steady-state response also has smaller oscillations about 2 volts for using proposed NMPC.

Design and Implementation of Active Clamp Flyback Converter for High-Power Applications

This paper proposes a solar-powered isolated DC–DC converter for high-power applications. The main aim of this paper is to achieve voltage regulation in the output side of the converter and to integrate a lossless active clamp flyback circuit (LACF) to compensate for the high-voltage issues that arise from one-stage DC–DC converters. Hardware is developed with a power rating of 2 kW to test the performance of the proposed circuit. The circuit is designed using low-voltage devices and features such as soft switching and regeneration due to the LACF, which enhances efficiency. A novel luminous control algorithm is presented to improve the converter performance. The proposed circuit’s performance and feasibility are compared with existing converter parameters, such as the number of components in the circuit, voltage rating, and regeneration.

Adaptive Dead-Time and Partial-ZVS Regulation for GaN-Based Active Clamp Flyback Converter With Predictive Hysteresis Current Mode Control

Active clamp flyback (ACF) converter is regarded as a good candidate in high-frequency small-size adapters. With adaptive dead-time optimization method, there is no reverse conduction loss and switching-on loss in power switches, then ACF can realize optimum full-ZVS control at every operating conditions. However, the other losses such as the conduction loss of clamp switch, the primary winding loss of transformer may be increased to counteract this efficiency advantage, but which has not been outlined. Therefore, this paper proposes a higher-efficiency predicted hysteresis current mode (PHCM) control strategy with adaptive dead-time and partial-ZVS regulation for GaN-based ACF converter for the first time. Firstly, the accurate analytical model by considering above losses is derived. Secondly, the optimal valley current is calculated by the minimum loss, to determine the conduction time of clamp switch and the dead time of main switch. Finally, a digital controlled GaN-based ACF converter is designed to verify the method. The computation speed of needed analytical equations and the magnetizing inductance offset are considered in implementation process. The experimental results show the proposed method can improve efficiency by 0.4% than existing method, which also show a fast dynamic response since the cycle-by-cycle variable-frequency control concept.

An improved coupled inductor‐based quadratic step‐up DC–DC converter with a high step‐up factor and reduced voltage overshoot on the power switch

AbstractMost coupled inductor‐based step‐up DC–DC converters encounter a significant voltage overshoot on their power switch due to the leakage inductance of the coupled inductor. So, they need additional bulky snubber circuits or a sophisticated procedure for coupled inductor design to reduce that effect. This paper proposes an improved coupled inductor‐based DC–DC converter, which provides a high quadratic voltage conversion ratio without excessive voltage stresses on the power switch. An active clamp circuit that operates with the zero‐voltage switching (ZVS) feature has been utilized for this aim. This feature allows the main power switch to be selected from low voltage ratings and low on‐resistance MOSFETs, which reduces conduction loss. The topology also benefits from continuous input current, high gain, high efficiency, and an appropriate number of components compared with the produced gain. In this article, the theory and operation of this converter are described by proposing the dc and small‐signal models, loss model, and continuous and discontinuous current modes (CCM and DCM) relations. Experimental results are represented to evaluate the performance of the proposed topology. For this purpose, a 240 V/240 W prototype has been designed and fabricated. Results confirm the above claims.

A ZVS-Based Non-Isolated High Step-Up DC–DC Converter With Low Voltage Stress for Renewable Applications

A high gain soft switched step-up DC-DC converter is presented in this paper. High gain is achieved at lower duty and turns ratio with a pair of coupled inductors and a voltage multiplier. In addition, an active clamp is incorporated to reduce the voltage stress across the main switch. Hence, switches with lower on-state resistance ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R_dson</i> ) and lower voltage ratings are employed, reducing both conduction losses and cost. It additionally helps in achieving zero voltage switching (ZVS) to both MOSFETs. By recycling the leakage energy of the coupled inductors, voltage gain is further increased. It also helps to accomplish zero current switching (ZCS) turn-on and off of diodes. This further reduces losses and increases further efficiency. Moreover, the reverse recovery problem of the diodes is also mitigated. The working principle, steady-state analysis, and design guidelines have been carried out. Finally, a 500 W hardware set up with an input voltage range of 20-24 V and output of 400 V at a switching frequency of 50 kHz is built to validate the performance of the proposed converter. The operating efficiency at full load is observed as 95.11%.

Multiplexed Active Clamp High-Frequency Link Inverter With De–Re-Coupling Frequency Doubling Modulation

In this paper, a multiplexed active clamp high-frequency link inverter (MACHFLI) with de-re-coupling frequency doubling modulation (DFDM) is proposed. The proposed MACHFLI consists of a primary inverter, high-frequency transformer, multiplexed active clamp (MAC) circuit, and cycloconverter. MAC recycles leakage inductance energy and eliminates voltage spikes caused by leakage inductance. Overlapping commutation is designed in the DFDM to ensure the safe commutation of the output filter inductor current and realize the ZVS of the cycloconverter. The ZVS of the primary inverter can be realized utilizing magnetizing current, and full-range ZVS of MAC can also be realized with turn-on delay. The operating principle and ZVS conditions of the proposed MACHFLI are analyzed, and the design of the transformer and clamp capacitor is discussed in this paper. Finally, a 1kW prototype is made to verify the analysis results. Experimental results show that MACHFLI has Four-quadrant operation capability, good dynamic response, high efficiency over a wide load range, and peak efficiency reaches 95.4&#x0025;.