Exciteringsström

Exciteringsström, also known as excitation current, refers to the electric current applied to an electromechanical device, such as an electric motor or an alternator, to establish a magnetic field in its stator or rotor windings. This current is essential for the operation of these devices, as it creates the necessary magnetic flux required for energy conversion between electrical and mechanical forms.

In synchronous machines, such as alternators or synchronous motors, exciteringsström is typically supplied to the rotor windings via slip rings or brushes. The strength of the excitation current directly influences the machine’s voltage regulation, power factor, and overall performance. For example, in generators, increasing the excitation current strengthens the magnetic field, raising the generated voltage. Conversely, reducing it lowers the voltage output.

Exciteringsström can be either direct current (DC) or alternating current (AC), depending on the machine design. In DC excitation systems, a separate DC source, such as an exciter or rectifier, provides the current. Modern systems often use electronic exciters, which offer precise control over the excitation current, improving efficiency and stability.

Proper control of exciteringsström is critical in power systems to maintain voltage stability, prevent over-excitation or under-excitation conditions, and ensure reliable operation. Over-excitation can lead to excessive reactive power generation, while under-excitation may result in voltage collapse or instability. Advanced control techniques, such as automatic voltage regulators (AVRs), are commonly employed to regulate exciteringsström dynamically in response to system demands.