växelfrekvensen

Växelfrekvensen, often translated as switching frequency or commutation frequency, refers to the rate at which an electronic switch changes its state in a power electronic converter. This switching action is fundamental to how these converters operate, allowing them to transform electrical power from one form to another. Examples of such switches include transistors like MOSFETs and IGBTs, or diodes.

In DC-AC converters (inverters) and AC-DC converters (rectifiers), the switching frequency dictates how quickly the input voltage or current is chopped and reassembled to produce the desired output. For DC-DC converters, it influences the duty cycle and thus the output voltage. A higher switching frequency generally leads to smaller passive components like inductors and capacitors, which can reduce the overall size and weight of the converter. It can also improve the dynamic response of the converter, allowing it to react more quickly to changes in load or input conditions.

However, increasing the switching frequency also comes with drawbacks. Each switching transition involves energy losses within the semiconductor device itself. These switching losses increase with frequency, leading to lower efficiency. Additionally, higher switching frequencies can generate electromagnetic interference (EMI), requiring more complex filtering and shielding. The optimal switching frequency is therefore a trade-off between component size, efficiency, cost, and EMI considerations for a specific application.