High frequency AC noise suppression within transformers
A transformer configured for use in connection with a variable speed motor drive includes primary windings and secondary windings. The secondary windings are configured as wye-windings and a ground lead and a plurality of phase leads. The transformer includes a ferrite blocking circuit connected to the ground lead.
1. A transformer comprising:
primary windings;
secondary windings, wherein the secondary windings include a ground lead and a plurality of phase leads; and
a ferrite blocking circuit connected to the ground lead, wherein the ferrite blocking circuit comprises:
a ferrite element;
a conductor coupled to the ground lead and extending through the ferrite element; and
wherein the ferrite element comprises one or more ferrite rectangular bodies secured to an exterior surface of the conductor.
2. The transformer of claim 1 , wherein the primary windings are configured in a delta winding configuration.
3. The transformer of claim 1 , wherein the primary windings are configured in a wye winding configuration.
4. A pumping system comprising:
an electric motor;
a power supply;
a variable speed drive; and
a transformer connected to the variable speed drive, wherein the transformer comprises:
primary windings;
secondary windings, wherein the secondary windings include a ground lead; and
a ferrite blocking circuit connected to the ground lead of the secondary windings; and
wherein the ferrite blocking circuit comprises:
a ferrite element; and
a conductor coupled to the ground lead and extending through the ferrite element; and
wherein the ferrite element comprises one or more ferrite rectangular bodies secured to an exterior surface of the conductor.
5. The pumping system of claim 4 , wherein the transformer is a step-up transformer connected between the variable speed drive and the electric motor.
6. The pumping system of claim 4 , wherein the transformer is an input transformer connected between the power supply and the variable speed drive.
7. A transformer comprising:
primary windings;
secondary windings, wherein the secondary windings include a ground lead and a plurality of phase leads; and
a ferrite blocking circuit connected to the ground lead, wherein the ferrite blocking circuit comprises:
a ferrite element;
a conductor coupled to the ground lead and extending through the ferrite element; and
wherein the ferrite element is coupled to the ground lead in a parallel relationship.
8. The transformer of claim 7 , wherein the ferrite element is coupled to the ground lead in a series relationship.
9. The transformer of claim 7 , wherein the ferrite element is secured to an exterior surface of the conductor with banding.