Växelväxelomvandling

Växelväxelomvandling, often translated as AC-AC conversion, refers to the process of changing alternating current (AC) from one voltage and frequency to another. This is distinct from AC-DC conversion (rectification) or DC-AC conversion (inversion). AC-AC converters are primarily used to modify the characteristics of an AC power supply without converting it to direct current and then back to AC.

There are two main categories of AC-AC converters: direct and indirect. Direct AC-AC converters, also known as cycloconverters, achieve the conversion by synthesizing the output waveform from segments of the input waveform. This method is generally suitable for lower frequency applications and can introduce harmonics. Indirect AC-AC converters first convert the input AC to DC using a rectifier, then convert the DC to the desired AC output using an inverter. This approach offers greater flexibility in controlling both voltage and frequency and generally produces a cleaner output waveform, but it involves more stages and potentially higher losses.

Applications for AC-AC converters include variable speed drives for AC motors, power supplies for specific industrial equipment, and voltage regulators. They are essential in situations where the standard grid frequency or voltage is not suitable for a particular load. The choice between direct and indirect conversion depends on factors such as the required output waveform quality, efficiency, cost, and the specific application's needs.