No abstract

In this study, a new interleaved full soft switching DC-DC boost converter with a high power reliability is proposed. To achieve soft switching, a simple auxiliary circuit consisting of one switch, one diode, one inductor and two capacitors is employed in each single-phase DC-DC boost converter connected in parallel. All switches and diodes, including main and auxiliary ones, operate under soft switching conditions. These soft switching conditions consist of zero voltage and zero current switching (ZVZCS) for all switches and diodes at switching transitions except the output diodes, which turn off only with zero current switching. The soft switching technique used in this study decreases power losses which leads the converter to have higher efficiency and reliability. Also, the auxiliary circuit is located out of the main power path preventing high voltage and current stresses on the switches. In this study, operational modes analysis, design procedure, power reliability evaluations and laboratory prototype results with switching frequency of 20 kHz, input voltage of 48 V and output power of 40 W are presented. T R component temperature rise above T AO R sng , R int single-phase and interleaved converters power reliabilities, respectively

No abstract

In this study, a new bipolar DC-DC converter based on the combination of a multi-port dual active bridge and a neutral point clamp topology is proposed. This topology provides the integration of multiple renewable energy sources, with different types and capacities, to a bipolar medium voltage DC micro-grid. The main advantages of the proposed topology are its high power density and the reduced number of switches with respect to the combination of different converters. Moreover, it provides isolation which is crucial for some micro-grid power conditioning converters. The proposed converter is employed for a typical hybrid generation system consisting of a photovoltaic (PV) system, a fuel cell (FC), and a battery (BAT) considering the characteristics of each power generation system like maximum power point tracking of PV, optimum operating region of FC and over-charge/discharge of BAT. In addition, the proposed converter is simulated in different power sharing modes in MATLAB/ Simulink software environment. Eventually, the theoretical and simulation analyses are validated by experimental prototype results.

No abstract

A new dual-coupled inductor (CI) single-switch high stepup DC-DC topology featuring high-power density is proposed in this study. Various capacitive power transfer methods, as well as inductive power transfer techniques, are utilized to act as a more efficient power interface between the input and the load. Three ports in the output terminal are employed to distribute the overall output voltage, diminish the voltage ripple in high-voltage gain ratios, and decrease the voltage stress on the port component. In the proposed converter, (i) the voltage gain is high in lower duty cycles of the switching; (ii) the stored energy of magnetizing and leakage inductances are recycled in both Cls; (iii) the switch voltage spikes are alleviated; (iv) the operation is done with no circulating current; (v) low-size passive components are presented; (vi) high-power density is obtained, and the voltage range is widened, and (vii) a simple PWM utilizing a wide control range is provided. In this study, the steady-state operation is analyzed under both continuous conduction mode (CCM) and discontinuous conduction mode (DCM), and the performance of the converter is evaluated using comparisons with similar works. In addition, the experimental results have been provided to justify the feasibility of the design.

No abstract

In this paper, a new family of ultra-high step-up DC-DC converters based on a center-tapped coupled inductor (CI) is proposed. These single-switch converters employ different inductive and capacitive power transfer techniques by utilizing multi-winding CIs, intermediate capacitor links and simple switchedcapacitors to improve the transferred power rate, harvest magnetizing and leakage inductance energies, and enhance power density. Achieving high voltage gain in low duty cycle values enables the proposed converters to operate under wide output voltage ranges; meanwhile, distributing the output voltage on two or three output ports alleviates the voltage stress on output terminal components. Low input current ripple, simple pulse width modulation control, low switch voltage stress and operation without circulating current can be listed as other features. In this paper, the proposed family is introduced, theoretically analyzed and compared with other state-of-the-art researches. Finally, the accuracy of analyses are evaluated with some experimental tests of a 1.25 kW experimental prototype.INDEX TERMS DC-DC converter, high step-up power converter, center-tapped coupled inductor.