Distribution System Training

The objective of this module is to look at complex circuits; that is those with capacitive, inductive and resistive elements connected in series. The impedance triangle, voltage triangle, and power triangle are all developed. Also discussed is the effect of impedance in causing voltage drop and phase angle difference in transmission and distribution lines. A brief review of basic trigonometry is included for those who feel that a refresher would be worthwhile.

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

• The resolution of right angle triangles using basic trigonometry and the Pythagorean theorem
• The calculation of overall impedance in a complex circuit, consisting of resistance, inductance, and capacitance in series
• Construction of the impedance triangle
• Calculation of voltage drop across each element of the circuit
• Construction of the voltage triangle
• Calculation of active power, or reactive power, drawn by each element of the circuit
• Construction of the power triangle
• The effect of series resonance in a circuit
• The effect of parallel resonance in a circuit
• The effect of frequency on resonance
• Vector representation of voltage drop in transmission lines and distribution lines
• The effect of load power factor on line voltage drop