ACGeneratoren

ACgeneratoren, or AC generators, are machines that convert mechanical energy into electrical energy in alternating current. They operate on the principle of electromagnetic induction: relative motion between a magnetic field and conductors induces an alternating voltage in the windings. In most designs, either the rotor or the stator provides a rotating magnetic field while the other component carries the armature windings.

Most AC generators used for power generation are synchronous machines. In a synchronous generator, the rotor has permanent magnets or DC-excited electromagnets that rotate at a speed set to match the grid frequency, with the number of poles determining the frequency. The frequency f is equal to the rotational speed multiplied by the number of poles and divided by 120. Induction generators, in contrast, rely on the grid to induce current in the stator and are common in smaller installations or when grid connection is straightforward. Rotor designs include salient-pole and non-salient (round) types, influencing stability and cooling.

Voltage in AC generators is controlled by excitation and regulation. An automatic voltage regulator adjusts the excitation current to maintain output voltage under changing load. Synchronous generators are widely used in centralized power plants and large facilities, often driven by steam, gas, or hydro turbines. Induction generators are used in applications such as wind turbines and some microgrids, where external reactive power control is available.

AC generator installations vary from portable units to large industrial plants, offering standby, prime, or grid-supplied power. Efficiency, maintenance, and protection systems are important considerations for safe and reliable operation.

See also: generator, alternator, synchronous generator.