A single-switch quadratic buck-boost converter with continuous input port current and continuous output port current is proposed in this paper. Compared with the traditional buck-boost converter, the proposed converter can obtain a wider range of the voltage conversion ratio with the same duty cycle. Moreover, the proposed converter can operate with continuous input port current and continuous output port current compared to the existing counterparts with inherently discontinuous input port current and discontinuous output port current. The operating principle and steady-state performance of the proposed converter under continuous inductor current mode is analyzed in detail. Then, the comparison between the proposed converter and the existing quadratic buck-boost converters has been conducted to demonstrate the unique features of the proposed one. Finally, experimental results from a prototype built in the lab are recorded to verify the effectiveness and validity of the proposed quadratic buck-boost converter.

A novel boost converter is proposed in this paper, which consists of three active Z-networks and is then named as a 3-Z-network boost converter. A distinct advantage of this proposal is that it can reach a high-gain voltage and well fulfill the stringent requirements from industry, particularly renewable power systems, to boost low voltage from clean sources such as photovoltaic (PV) arrays and fuel cells to high voltages for grid-connected converters. Corresponding to different states of the diodes and currents of the capacitors, six operational cases of the proposed converter, including two continuous-current modes (CCMs) and four discontinuous-current modes (DCMs), are analyzed. It is then followed with the parameters design. Finally, simulations and experiments are conducted to verify the effectiveness of the proposed converter.

An impedance network dc-dc boost converter is developed in this letter. Compared to the conventional boost converter, it can reach a higher voltage gain with fewer diodes and a small duty cycle (smaller than 33%) and, meanwhile, avoid instability caused by saturation of its inductors, whereas the conventional boost converters realize high-voltage gains at rather large duty cycles (normally exceeding 50%) resulting in saturation of inductors. Furthermore, it can well fulfill the stringent industrial requirements, particularly of renewable power systems. The proposed converter with continuous conduction modes is analyzed for different states of its components. Then, it is shown how to determine its various parameters. Finally, simulations and a 250-W prototype are conducted to verify the converter's effectiveness.