Armature flux is the magnetic flux created by the current flowing through the windings of the armature in an electrical machine, such as a dynamo, when it is connected to a load.
Understanding Armature Flux
In electric generators (dynamos) or motors, the armature is the rotating part that carries the main current. When the machine is under load, current flows through the armature windings. This electric current, like any other current, generates a magnetic field around the windings, and this magnetic field is referred to as the armature flux.
How Armature Flux is Created
The creation of armature flux is a direct consequence of the machine being in operation and under load. Specifically:
- The machine (e.g., a dynamo) is connected to an external circuit or load.
- This connection allows current to flow through the armature windings.
- When the dynamo is connected to a load, current flows in the armature windings.
- This results in an armature flux.
This process occurs in both generators and motors whenever current flows in the armature.
Impact on Main Flux
The armature flux is significant because it interacts with the main magnetic flux produced by the field poles (often called the field flux). This interaction leads to a phenomenon known as armature reaction.
According to the reference:
- The armature flux distorts the main magnetic flux.
- The main flux (fig. 16-30) is increased as it exits the poles and weakens where it enters the poles.
This distortion means the main flux field is no longer uniformly distributed across the air gap but is skewed or twisted by the presence of the armature flux. This effect can impact the machine's performance, including voltage regulation in generators and torque production in motors.
In summary, armature flux is a secondary magnetic field generated within an electrical machine's armature due to load current, which significantly interacts with and distorts the primary magnetic field from the field poles.
