A model-based controller for a DC-DC boost converter with an LCL input filter

This work has adopted the concept of asymmetric inductor magnetization to develop a new quadratic converter with the advantages like a wide range quadratic voltage gain and low source current ripple. In addition, the proposed high quadratic converter has achieved reduced voltage stress due to the presence of switched capacitor cell at the output side. Initially, the operation of the converter and steady-state analysis, including efficiency calculations, are explained. In addition, the design and selection of converter components are presented along with a small-signal analysis. Further, a comprehensive comparison with recent high quadratic gain converters is presented. The comparison is made with regard to the total component count, voltage conversion ratio, effectiveness index, electric stress, current ripple, switching device power (SDP) rating, and input current ripple factor. Furthermore, the 150 W laboratory prototype is used to verify the performance of the proposed converter in terms of operation, dynamic response, and efficiency, and the corresponding experimental findings are reported. The wide range voltage gain, low current ripple, and low electric stress features of the proposed converter highlight its superiority in fuel cell electric vehicle applications.

In order to solve the problem of insufficient boost capability and system stability of traditional boost converter, an isolated quasi-Z-source (qZS) high step-up dc-dc converter with three switches is proposed in this paper. In comparison with conventional qZS converter, reduced one active switch, the proposed converter has significant step-up voltage conversion ratio, lower voltage stress across the active switching devices and continuous input current with low current ripple. The operation principle, the design of the parameters, the performance compared with other step-up converters are presented. Finally, the simulation model is built by Matlab/Simulink to verify the correctness of the theoretical analysis.

Comparison of the input filter effect to PV panel by SEPIC MPPT converter

An interleaved buck-boost converter with a wide conversion ratio is proposed in this paper. Two converter cells are used in the porposed converter. One is a single-ended primary inductor converter (SEPIC) and the other is a Cuk converter. Since both converter cells have an inductor and a switch, the input current of the proposed converter has low current ripple by utilizing an interleaving technique. The SEPIC converter cell provides a positive step up/down output and the Cuk converter cell provides a negative step up/down output. Therefore, the proposed converter has also step up/down capability and a wide conversion ratio. The proposed converter has a low input current ripple, step up/down capability, and a wide conversion ratio. Theoretical analysis and performance of the proposed converter were verified on an experimental prototype operating at 100 kHz switching frequency.

To balance the cost and volume when applying a low output current ripple, the power supply design should be able to eliminate the current ripple under any duty cycle in medium and high switching frequencies, and considerably reduce filter volume to improve power density. A stacked buck converter was eventually selected after reviewing the existing solutions and discussing their advantages and disadvantages. A stacked buck converter is used as a basis to propose the transient response and output current ripple elimination effect, boundary limit control method, and low output ripple dead time modulation method to make individual improvements. The principle, mathematical derivation, small-signal model, and compensator design method of the improvement method are presented in detail. Moreover, simulation results are used to mutually verify the correctness and effectiveness of the improvement method. A stacked buck converter with 330-V input, 50-V output, and 1-kW output power was implemented to verify the effect of the low output current ripple dead time modulation. Experimental results showed that the peak-to-peak value of the output current ripple was reduced from 2.09 A to 559 mA, and the RMS value was reduced from 551 mA to 91 mA, thereby effectively improving the output current ripple.

This paper proposes novel bidirectional DC-DC converter that has the advantages of high voltage gain, low conduction losses and low input current ripple. Two paralleled current-fed full bridges are located in the low voltage side (LVS), sharing one voltage-fed full bride in high voltage side (HVS). A quadruple phase-shift control strategy is proposed to reduce input current ripple and conduction loss. The phase shift between the full-bridges of LVS is employed to greatly reduce current ripple and the auxiliary inductors are used to help the lag bridge extend the zero-voltage-switch (ZVS) range. Finally, an 800W simulation prototype is built to verify the proposed converter, the accordance between the analysis and simulation results testify the advantages.

The model predictive direct speed control (MPDSC) can improve the speed dynamic performance effectively. However, due to the large difference between the mechanical and electrical time constants, short prediction could result in large current ripples at steady state, which becomes a critical problem. Besides, the conventional MPDSC methods have not deeply investigated the online-adjustable weighting factor design and the problem of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i_d</i> transient oscillation. In this article, a model predictive direct speed control with novel cost function is proposed. In the proposed method, two different <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i> -axis current references are generated, one to improve the speed dynamics, and the other to ensure the low current ripples. The two current tracking are assigned with different weighting factors unified in one cost function. In order to determine which current tracking to play a major role under different operations, the speed error is designed as weighting factor. With the proposed cost function and designed weighting factor, the high speed dynamics and low steady current ripples can be achieved simultaneously. Finally, the effectiveness of proposed method is verified by experiments.

Battery Pack life time depending on thermal management is a crucial issue in Electric and Electric Hybrid vehicles. Excessive thermal losses caused by the battery current ripples can be well avoided by introducing suitable topology. This paper proposes utilization of interleaved DC-DC converters to reduce the battery pack current ripples. Interleaved converters have some advantages such as low current ripple, low losses and high reliability. This paper considers Ni-MH batteries used in Toyota Prius 2010 and takes the high frequency model of Ni-MH battery into account to show the effect of ripple current on battery. While design equations and considerations are explored, conventional converter and interleaved DC-DC converter are modeled and simulated to study and compare the battery current ripples in boost and buck modes of operation. It is shown that current ripples of interleaved converter are much lower resulting in extension of battery pack life time.

An improved forward-flyback converter for electrolytic capacitor-less (E-cap less) LED driver with high power factor (PF), high efficiency, low output current ripple and long lifetime has been proposed and studied in this paper. The improved topology consists of a single switch forward-flyback converter in order to achieve high PF. In addition, a buck converter is inserted between the forward sub-converter and the load to create two parallel paths for power transfer. The most of power directly reaches the load through flyback sub-converter, and only a small part of the total energy reaches the load through forward sub-converter and buck converter. Therefore, the power decoupling can be realized and the electrolytic capacitor can be eliminated based on the proposed “one-and-a-half stage” converter. Optimal control scheme, detailed analysis and design considerations for this improved converter are presented. Finally, an experimental prototype for 28V/700mA LED driver was built up to verify the theoretical analysis.

In this paper, residential loads are modeled in order to analyze low frequency current ripples of residential fuel cell applications. A difference of low frequency current ripples between simple resistor load condition and actual residential load conditions is compared. Aspect of generation and propagation of low frequency current ripples are analyzed in order to design an optimal power conditioning system. Theoretical analysis has been performed and informative simulation and experimental results are provided.

In order to meet the high current quality and low leakage current requirements in high power rating photovoltaic applications, an improved carrier-based modulation (ICBM) for parallel converters is presented in this article. Different from existing methods which are based on phase-shifted pulsewidth modulation, a proper zero-sequence modulation wave is injected into the three-phase modulation waves to achieve a low total current ripple based on the root mean square value analysis of the output current ripple. Aside from this, the initial phase shift angles for the carriers in each converter are modified to minimize the excitation source of leakage current, while the quality of total output current is not affected. Furthermore, the proposed ICBM is extended to parallel multilevel converters according to the vector shift principle. By using the proposed ICBM, total current ripple reduction and leakage current attenuation in parallel converters can be achieved simultaneously. Experimental results validated the correctness and effectiveness of the proposed method.

Electrolyzers are widely used in renewable energy hydrogen production, and the performance of electrolyzers is directly related to dc–dc converters. To realize the high-efficiency operation of the electrolyzer, new challenges, such as a high step-down ratio and low output current ripple, are put forward for the dc–dc converter. In this article, we propose a novel type of dc–dc converter for hydrogen production. The topology is simple and has the advantages of higher step-down gain and low switching stress. In addition, the scheme can achieve ultralow output current ripple without active devices. Finally, the topology connects the electrolyzer hydrogen production load in the experiment to verify the scheme's effectiveness.

In recent years, the trend in converter technology has been towards higher efficiency. This trend often involves using advanced semiconductor materials and better control algorithms to mitigate potential failure modes. Despite these advancements, converter failures can still occur due to various factors including design flaws, manufacturing defects, inadequate cooling, improper operation, and external environmental conditions. This paper provides the novel approach to enhance fault tolerance in DC-DC converter systems by introducing parallel switches that activate in response to faults occurring in primary switches. It Examine the effectiveness of this fault-tolerant design in three popular converter configurations like Boost converter, Luo converter, and Super lift Luo converter with a focus on achieving the best output voltage characteristics. The Super Lift Luo Converter (SLLC) is a type of DC/DC converter that combines the advantages of a conventional boost converter and a Luo converter. It offers features such as high voltage gain, reduced switch stress, and low input current ripple. The output voltage quality is a critical aspect in power electronics applications, influencing the stability and reliability of the power supply. Theoretical analysis, simulation, experimental validation and comparative assessment for Luo and super lift Luo converter are done. The objective is to maintain consistent output voltage despite faults occurring in primary switches, thereby ensuring system reliability and stability for renewable and EV applications. As the electrical vehicles mostly deals with 48 V these converters are predominant in providing this value of supply.

Switched mode pulse power supply is a promising technique for high-power quasi-continuous laser driver. Contrast to lossy linear laser drivers, switched mode laser drivers can achieve higher efficiency. However, many challenges have been proposed, such as fast pulse edge, low current ripple. This paper proposes a multiphase interleaved pulse power supply with energy recovery and inductive storage (MIEF-PPS). The basic concept of the topology is the inclusion of a multiphase converter with pulse forming circuits to the converter system, which decouples the current slew rate and current ripple. Using an inductive storage technology and pulse forming circuits, a shorter pulse current rising time is obtained. The inductor energy is fed back to the input source not discharged to the load, resulting in a fast pulse trailing edge and energy saving. Thus the pulse current response observed when using this proposed technique is found to be much faster when compared to the conventional interleaved buck driver. Moreover, a pre-charge method is proposed to overcome the challenge of digitally controlling the inductive storage. The proposed topology was simulated in MATLAB/Simulink and validated against the experimental results of a laboratory prototype, 360 W dual-interleaved pulsed power supply.

The Weinberg converter is a suitable choice for the battery discharge regulator of a geostationary satellite due to its high efficiency, continuous input and output current, and soft switching of switches and diodes. Nevertheless, this converter has high output current ripple during the commutation period of its output diodes. Therefore, the output RMS current and output voltage ripple are high, which may directly affect the lifetime and total capacitance of bus capacitors and hence, the lifetime and volume of the geostationary satellite. Thus, reducing the output current ripple is important to the design of the geostationary satellite. An improved Weinberg converter with an additional inductor and capacitor is proposed in this paper to reduce the output current and voltage ripple. It features soft switching of all switches, no reverse recovery problems of the diodes, and reduced magnetizing offset current in the coupled inductor. The proposed converter is verified with experimental results from a 750W, 100kHz, 36-50Vdc prototype.