Topologies for Power Converters

Versatile circuit topologies can be found in power electronics for differenct applications. In terms of conversion form, four categories can be identified: DC/DC converter, DC/AC converter (inverter), AC/DC converter (rectifier), and AC/AC converter (cycloconverter). Aiming at reducing switching losses and EMI of power converters, a lot of soft switching techniques are developed for above mensioned four types of converters so that high effiency, small size, low weight can be achieved.

• buck converter
• boost converter
• buck/boost converter
• cuk converter
• forward converter (isolated buck)
• flyback converter(isolated buck/boost)

• voltage-fed inverter
• current-fed inverter

Examples of inverters: Three Phase Inverter, Flywheel energy storage system.

An AC/DC converter is usually used as a front-end converter in a power electronics system. A front-end converter has to be friendly to the utility line, that means high power factor, low input current THD(total harmonic distortion, and low EMI emission. To meet more and more strict regulations, advanced AC/DC converters have been developed for single phase system and three-phase system.

• single-phase boost PFC rectifier
• three-phase DCM boost PFC rectifier
• three-phase boost PWM PFC recitifer
• three-phase buck PFC rectifier