Commutation cell

The commutation cell is the basic structure in <a href="/facts/Power_electronics/8BAQ3jDP">power electronics</a>. It is composed of two electronic switches (today, a high-power <a href="/facts/Semiconductor/zFf3mGTE">semiconductor</a>, not a mechanical switch). It was traditionally referred to as a <a href="/facts/Chopper_(electronics)/tckYde1J">chopper</a>, but since <a href="/facts/Switched-mode_power_supply/YKcyRBtP">switching power supplies</a> became a major form of power conversion, this new term has become more popular.
The purpose of the commutation cell is to "chop" DC power into <a href="/facts/Square_wave_(waveform)/h1cWR1KM">square wave</a> alternating current. This is done so that an <a href="/facts/Inductor/YnfAXB3x">inductor</a> and a <a href="/facts/Capacitor/hyowqv7n">capacitor</a> can be used in an <a href="/facts/LC_circuit/tzEfI7Hf">LC circuit</a> to change the voltage. This is, in theory, a lossless process; in practice, efficiencies above 80-90% are routinely achieved. The output is usually run through a <a href="/facts/Electronic_filter/ny7k6VxV">filter</a> to produce clean DC power. By controlling the on and off times (the <a href="/facts/Duty_cycle/B2tbtXTh">duty cycle</a>) of the switch in the commutation cell, the output voltage can be <a href="/facts/Regulated/eFR0l2x9">regulated</a>.
This basic principle is the core of most modern power supplies, from tiny <a href="/facts/DC-DC_converter/lVlyHrjs">DC-DC converters</a> in portable devices to massive switching stations for <a href="/facts/High_voltage/lUy99k3E">high voltage</a> DC power transmission.

Commutation cell open-in-new

Commutation cell