A High Step-Up PWM Non-Isolated DC-DC Converter With Soft Switching Operation

Abstract

A high step-up PWM non-isolated dc-dc converter with soft switching is proposed in this paper. The converter has minimum auxiliary elements to achieve high power density and high voltage gain. The ZVS operation of the main power switch results in negligible capacitive turn-on losses. Since the duty cycle of the auxiliary switch is narrow and its operation is under ZCS condition, the losses that the auxiliary circuit imposes are not significant. Also, all the diodes are operated under soft-switching conditions solving the reverse recovery problem. All the inductors are coupled on only one magnetic core, reducing size and conduction losses. Compared to the hard switched counterpart, the electromagnetic interference of the proposed converter is reduced. Furthermore, the output voltage of the proposed converter is controlled by an integral sliding mode control strategy during the load variations. Also, the proposed integral sliding mode control strategy has been compared with the PI control strategy, improving the transient response and the robustness under load variations while the switching frequency is constant. The effectiveness and accuracy of the proposed converter are verified by practical laboratory results which are obtained from a 250W prototype.

A new three winding coupled inductors high step‐up DC–DC converter with low input current ripple

“…This condition is also observed for changing the load from full to half. Based on this figure and the experimental results obtained, when the load changes from low to high, the output voltage drop is about 40 volts, which the control circuit compensates for this volt-FIGURE 12 The experimental results of D 1 current (vertical scale is 2 A/div and horizontal scale is 1 µs/dive).…”

“…Conventional boost converter is not suitable, because they are not able to provide high-voltage gains with low duty cycle and low losses. Therefore, in recent years, high step-up converters have become particularly important [12][13][14]. These converters have high voltage gain to deliver very low level voltage to high level voltages and apply to the inverter [15].…”

A soft switched step‐up DC–DC converter using a low‐power auxiliary circuit and continuous input current

“…Although some converters have less number of components in comparison with the proposed converter, the soft switching is not fully applied in them [4, 19]. The numbers of components in [15, 16] are also less than the proposed converter. Besides, the soft switching is fully applied in these converters.…”

“…However, this reduces the efficiency. The voltage gain of the proposed converter and the converters proposed in [8, 15, 16] are approximately equal. The normalized sum of the product of the voltage and current stresses of all the semiconductors is more than the proposed converter.…”

Study and Implementation of a High-Quality True Sine Wave DC-to-AC Inverter for Solar Power Generation Systems

“…Most of these MPPT algorithms cannot strictly analyze the convergence and stability, or cannot quickly track the maximum power point, resulting in the reduction of output power. Sliding mode reaching law (SMRL) is simple and easy to design, and is robust to parameter changes and external disturbances in smooth motion [ 10 , 11 ]; many related SMRL applications have been published in the control of solar power generation systems [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. However, in practice, the solar system controlled by the SMRL is affected by uncertainty, the system state convergence time is not limited, and steady-state errors will occur, which will affect the stability, convergence, and performance of the system.…”