Distribution System Training

The objective of this module is to present the basic principles of three phase power, including the characteristics of Wye and delta connections. The fundamentals of two winding and autotransformers are discussed, including various combinations of three-phase transformer connections.

Finally, bearing in mind the special applications of DC in power systems, the characteristics of DC circuits are introduced.

After completion of this module and associated workbook, the participant should be able to understand and apply the following concepts in day-to-day work activities.

• The advantage of three phase power systems
• Sharing the common neutral
• Elimination of the neutral conductor with a balanced three-phase load
• The generator Wye connection and grounded neutral
• The Wye connection voltage and current relationships
• The delta connection, voltage and current relationships
• Expression for power in a three-phase circuit
• Fundamentals of voltage transformation
• Function of the iron core in the transformer
• Transformer voltage and current relationships
• Transformer energy losses
• Transformer single phase and three-phase construction
• Characteristics of the transformer delta-delta connection
• Characteristics of the transformer Wye-delta connection
• The function of transformer tap changers
• The function of the autotransformer
• The difference between DC and AC electric power
• The effect of inductance and capacitance in a DC circuit
• Battery discharge and re-charge
• The DC generator
• Half wave solid-state rectification
• Full wave solid-state rectification
• Typical applications of the solid state rectifier