A single‐phase p‐type ac–ac converter with reduced components count and high boost factor

Abstract

This paper proposes a new single‐phase direct step‐up ac–ac converter by modifying the p‐type impedance source. It provides a high boost factor as well as high efficiency, while only six parts are required to design it, involving just two bidirectional power switches. A safe commutation method has been applied to power switches to make the converter snubber‐free and high efficient. Input and output harmonic filters are no longer required since input and output currents variate continuously with small ripple and low total harmonic distortion (THD). The proposed topology only modulates the output voltage amplitude, not the phase and frequency, so the output frequency is identical to the input frequency and constant. Thus, it can be utilized in step‐up conversion applications, like inductive power transmission from low ac voltage sources. Input and output have the same ground, which is a good protective feature. In this paper, the operating principle of the converter is demonstrated. Experimental results have been represented to evaluate the performance of the converter. For this purpose, an experimental prototype has been fabricated. Results are investigated and compared with other previous step‐up ac–ac converters. Results confirm the theory, operating principle, and performance of the converter.

An isolated high‐gain impedance source‐based single‐phase AC–AC converter with safe commutation and variable output frequency

“…Direct AC-AC converters are the second type of AC-AC converters, only used for regulating the output voltage amplitude. [22][23][24][25][26] The direct AC-AC converters' idea is derived from the DC-DC topologies by using bidirectional switches instead of the converter semiconductors with the unique safe commutation strategy. The efficiency has been improved by reducing the power switch counts.…”

“…Two‐stage power conversion is another demerit of this type of converter, reducing efficiency. Direct AC–AC converters are the second type of AC–AC converters, only used for regulating the output voltage amplitude 22–26 . The direct AC–AC converters' idea is derived from the DC–DC topologies by using bidirectional switches instead of the converter semiconductors with the unique safe commutation strategy.…”

High step‐up direct ac‐ac boost converter with optimal component counts based on SEPIC

“…In this case, the output power quality is a target, not the buck-boost operation. The family of single-mode PWM ac-ac converters consists of P-type [29], dual-buck converter [30], switched-boost converter [31,32], Cockcroft-Walton [33], and switched-capacitor boost structure [34]. By reviewing previous literature, the following problems are surveyed: I.…”

A bidirectional single‐phase Z‐source AC‐AC converter with reduced voltage stress on switches and safe commutation strategy

“…Reducing the cost, volume, and weight of the power electronic converters is a crucial requirement for coming applications. In terms of power conversion type, matrix converters, [1][2][3] indirect ac-ac converters (ac-dc-ac), 4,5 and direct pulse width modulation (PWM) ac-ac converters [6][7][8] are the three major groups of ac-ac converters. Matrix converters can adjust the voltage and frequency at the output side, and with bidirectional switches, it is possible to transfer power in both directions.…”