Search

Partial shading on series‐connected photovoltaic (PV) panels in conventional PV systems results in lower harvested power. To resolve this, it is vital to utilize module level power electronics (MLPE) such as Solar Power Optimizers (SPOs). This paper introduced a non‐isolated common ground non‐inverting output voltage buck‐boost converter as an SPO. Proposed converter benefits from continuous input and output currents which has a significant role in designing SPOs. Having a quadratic gain, beside acceptable step‐down range are other features of the converter. Operating principle, design, steady‐state, small‐signal analysis, and dynamic performance of proposed converter are included. Proposed converter is compared with other buck‐boost converters in terms of voltage gain, voltage stresses, continuous input and output current, and output polarity. To validate the performance of introduced converter, experimental results for a prototype with input voltage 24 V, output voltage 72 V for step‐up and 15 V for step‐down modes are given and results are examined. The maximum efficiency of the prototype is 93% and 89% for step‐up and step‐down modes, respectively. To evaluate the effect of proposed SPO for extracting maximum available power from PVs, simulation results of a grid connected PV system with two series connected SPOs is discussed. [ABSTRACT FROM AUTHOR]

This paper proposes a new control method for loss reduction of two series buck converters. The proposed method can be applied to each series of buck converters with two power switches. To enhance the efficiency of the converter compared to other structures, a method based on determining operating cycles for loss reduction is employed, leading to increased output efficiency of the converter. Additionally, to demonstrate the efficiency improvement using the proposed method compared to the conventional approach, the efficiency of converter is calculated through theoretical computations under real conditions, and the output results are compared for both losses and efficiency. In addition, the proposed high‐buck converter in this paper benefits from a common ground advantage and exhibits a suitable conversion ratio. The high‐buck converters are used in numerous applications for situations with low voltage and low power. The most important applications for these converters are the power supply for mobile phones, tablets, and other portable electronic devices, battery chargers, and LED drivers. Here, in order to demonstrate the validity of the proposed method, the MATLAB‐Simulink results are provided. Moreover, in order to show the feasibility of the high‐buck converter, a 100‐W prototype has been implemented and the experimental results are provided. [ABSTRACT FROM AUTHOR]

Summary: This study proposes a new design for a non‐isolated buck converter with continuous input current. As required, the integration of additional modules into the existing structure permits a significant decrease in the converter's gain to attain significantly lower values. In order to create the proposed converter, the input voltage connections to the Ćuk converter were changed. In this configuration, the operational state of the Ćuk converter has been changed from buck‐boost to step‐down by connecting the input power source's negative polarity to the inductor's terminal. In addition, the proposed converter benefits from a common ground between the input source and output port. Moreover, it can achieve a significant reduction in gain by increasing the number of series modules. Finally, the compact converter was smoothly incorporated onto a printed circuit board (PCB) and afterward validated by an output power of 80 watts. [ABSTRACT FROM AUTHOR]

This study proposes a bidirectional DC–DC converter with low voltage stress on its semiconductor elements and high voltage gain. Bidirectional DC–DC converters play a crucial role in DC microgrid systems, and they have been used for many applications such as power flow management, battery storage systems, voltage regulation, and electric vehicle (EV) charging systems. This paper proposes a novel non‐isolated, bidirectional DC–DC converter with an improved voltage gain conversion ratio. In the structure of the proposed converter, the coupled inductor provides high voltage gain and is employed to reduce the overall voltage stress across the main switches. Additionally, a filter inductor on the input‐low voltage side of the converter reduces current ripple. In addition, a single switch is used in boost mode, which simplifies control of the converter. Furthermore, two power switches receive simultaneous pulses for adjusting the buck stage voltage gain. Also, in the following, the mathematical calculations and the small signal analysis for the proposed converter are provided. Furthermore, a 200 W prototype is finally implemented, and its results are validated by the theoretical analysis. [ABSTRACT FROM AUTHOR]

High voltage gain dc-dc converters are widely using in solar systems, fuel cell and automobile electronic lamp ballast. The voltage gain of the classic converters is limited considering the issues such as the high voltage stress on the switch and diode and low efficiency and because of this issues, high voltage gain dc-dc converter must be used. In this paper, a new high step up dc-dc converter based on KY converter is proposed. The proposed converter achieves high voltage gain with appropriate duty cycle. The proposed converter has low voltage stress on the active switch, which makes reducing the switching power loss. The operation modes of the proposed converter and the steady-state analyses of are presented in detail. To verify the operation of the proposed converter, simulation results in PSCAD/EMTDC software are provided.

This paper proposes an innovative structure for DC-DC converters with high buck gain by using a lower number of elements. The converter provides highly efficient output power and an extended output voltage range. In addition, the distribution of output current between two inductors and the soft-switching capability of the power switches have made the converter suitable for applications that require high output current. All power switches accomplish the ZVZCS (zero-voltage and zero-current switching) condition with the aid of a small auxiliary inductor (Lx), which charges and discharges parallel capacitors of main switches to provide soft-switching conditions. Thus, the switching losses associated with power switches are considerably reduced. Additionally, the output voltage ratio of the proposed converter can be changed by varying the switching frequency and duty cycle. In addition, the variation range of output voltage has been expanded compared to other topologies, allowing for a wider output voltage range. A coupled inductor is utilized to establish a relationship between the output gain and the turn ratios, resulting in a wider output voltage gain range. Eventually, a theoretical analysis is conducted and a 200-watt experimental prototype has been implemented to illustrate the proposed converter's efficacy. It converts a voltage input (300 V) to a voltage output (10 V). [ABSTRACT FROM AUTHOR]

In this paper, a new configuration of Marx generator with high‐voltage (HV) gain is presented for electroporation applications. Each module consists of one switch, one capacitor, and two diodes. The capacitors are charged in parallel with the input inductor and the input DC voltage source simultaneously; eventually, the charged capacitors are connected in series, and the HV output pulses are generated. The load is connected differently at the output stage, and there is not any switch at the output stage to generate the HV pulses. The majority of Marx generators suffer from the high number of modules to reach the desired pulse peak voltage. Due to the high‐voltage gain of the proposed topology, fewer modules are needed to achieve the desired HV pulse peak voltage. Mathematical analysis is presented along with a full design of the system components. Soft switching reduces the switching power loss in this converter, which is presented in detail. A comparative study is carried out to demonstrate the advantages of the proposed structure. Finally, simulation and experimental results are presented to validate the proposed concept. [ABSTRACT FROM AUTHOR]

This paper presents a new method for driving the magnetron for a sulfur plasma tube using the two‐switch forward converter structure with a phase‐shifting active clamp (1000±40 W, 285 mA, 4 kV). Depending on the output voltage level required, the magnetron driver circuit is boosted and insulated and also has high gain. The use of the two‐switch forward converter reduces the transistor voltage stress. In addition, applying the clamp structure balances the magnetization current. Besides, by controlling the phase shift of the clamp transistor, while maintaining the magnetic current balance of the power transformer, the duty cycle of the main transistors can be increased. This allows more voltage level transfer to the secondary winding of the transformer. Therefore, with a fixed transformer core, more voltage transmission is possible in comparison with a conventional forward converter. Moreover, using the PFC converter improves the power factor and stabilizes the DC‐link voltage. The magnetron driver circuit provides a maximum power of 1 kW with an average power of 125–250 W by adjusting the converter's active time under minimum loss conditions. The magnetron driver circuit provided is validated by the simulation and experimental results. [ABSTRACT FROM AUTHOR]

In this paper, a new transformerless buck-boost converter is presented. The voltage gain of the converter is higher than the classic boost converter, classic buck-boost converter, CUK and SEPIC converters. The proposed converter advantage is buck-boost capability. The proposed converter topology is simple; therefore, the converter control is simple. The converter has one main switch. Hence, the switch with low switching and conduction losses can be used. The stress of the main switch is low; therefore, switch with low on-state resistance can be selected. The principles of the converter and mathematic analyses are presented. The validity of the accuracy of calculations is verified by the experimental results. [ABSTRACT FROM AUTHOR]

In this paper, a new interleaved switched-capacitor bidirectional DC-DC converter with a high step-up/step-down voltage gain is proposed. In this converter, two inductors, four capacitors and four semiconductors are used. The voltage gain of the proposed converter is higher than conventional converters such as buck-boost, boost, Cuk and is compared with some new converters. In order to reduce the ripple of the current through the low-voltage side, an interleaved structure is adopted in the low-voltage side of this converter. Furthermore, the equations of the voltage, the voltage stress for switches and currents are presented in different modes. To verify the operation of the proposed converter, the experimental results are provided. [ABSTRACT FROM AUTHOR]