Sirens, electric motors and electric generators are examples of machines that rely on a stator. Made up of electrically-insulated windings and an iron core, stators vary in size. But they’re always an essential part of rotary systems.
A stator generally plays the role of an armature, which does two jobs. First, it carries current to create torque in a rotating machine.
Second, it generates electromotive force. If the stator itself isn’t a machine’s armature, it acts as a field magnet. This means it uses the armature’s electromotive force to cause a machine to rotate.
Electrical insulation for a stator is necessary to ensure a rotary system’s longevity. It separates the stator from thermal heat that wires generate. Insulation for a stator’s windings is typically bonded with either epoxy or asphalt polyester.
Unfortunately, electrical insulation can deteriorate from thermal, mechanical and environmental stresses if not monitored. Electrical insulation deterioration can lead to either hefty repair costs or irreversible damages. This is partly because the stator will incur core losses. Essentially, a rotary system will lose energy in its stator’s iron core. Because of the lost energy, a motor has to use more power to work.
However, partial discharge (PD) is a more severe consequence of poor insulation. PD comes from a breakdown of a small portion of solid, fluid or gaseous electrical insulation. This usually occurs under stress from high voltage. As a result, energy, which is typically in the form of heat, is dispersed. As PD becomes more frequent, insulating materials rapidly deteriorate. Electrical breakdown and complete failure are common consequences. When electrical insulation for a stator can’t do its job, a rotary system won’t last long.
This is why high quality, up-to-date electrical insulation or stators is essential. It will ensure a rotary system lives a long life without crippling repair costs.