جستجوی مقالات مرتبط با کلیدواژه "step-up converter" در نشریات گروه "برق"

Step-Up DC-DC Converters are widely used in electric vehicles, because the use of batteries and fuel cells increases the voltage level to drive the electric motor. One of the problems of step-up converters is the increase in volume and weight due to step-up transformers. So far, various methods, such as switched capacitor, coupled inductor and multiplier circuits, have been used to eliminate the transformer and reduce the volume and weight of the circuit. To further reduce the volume and weight of the circuit, it is necessary to increase the switching frequency, which is possible only by using the soft switching method. Using an auxiliary switch to create soft switching conditions is common in most methods, because not using an auxiliary switch imposes voltage and current stress on the circuit. In this article, a step-up converter with an auxiliary circuit of zero voltage transition (ZVT) is presented, which provides switching conditions at zero voltage to turn on the switch and switching at zero voltage to turn off the switch. The voltage stress of the converter is very low, and all the diodes are switched off at zero current, so they do not have reverse recovery problems. Also, in addition to absorbing the energy of the leakage inductor, the clamp capacitor helps to increase the gain of the converter. The provided converter is simulated in P-Spice software. To check the performance of the converter, a laboratory model with a power of 150 watts has been designed and tested.

A step-down converter based on buck and buck-boost converters with a loss reduction technique is proposed in this paper. Utilizing non-electrolytic capacitors in the implementation of the proposed converter has resulted in an increase in circuit life and a reduction in weight and volume. This paper compares the proposed converter to other buck converters. To increase the output efficiency of the converter in comparison to other structures, a new method based on determining the working duty-cycles has been employed to reduce the losses of the converter, resulting in an increase in the converter's output efficiency. In order to demonstrate the differences in efficiency between the proposed method and the conventional method, the efficiency of the converter has been calculated using real-world conditions and the output loss results have been compared. In addition, the proposed converter has a common ground with the input source and has a suitable reduction gain. Finally, this converter has been implemented as a PCB and tested with 100 watts of output power.