Distribution System Training

The objective of this module is to look at the different methods and equipment that are employed to adjust voltage throughout the distribution system.

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

• Voltage standards: – allowable variation at the customer’s service entrance
• Factors affecting voltage drop along distribution feeders
• The effect of raising voltage at the substation bus
• Transformer tap changing mechanism
• Automatic tap changing control circuit
• Action of tap changing contacts to maintain load current flow
• The application of tap changer vacuum break contacts
• Auto tap changer voltage sensing point
• Line drop compensation
• Limitations of voltage control at the substation bus only
• Application of the in-line voltage regulator
• Principal of operation of the in-line step voltage regulator (SVR)
• Pole top installation of SVR- connections
• Operation of the SVR by-pass
• Voltage profile improvement by boosting voltage at feeder mid-point
• The effect of load power factor on line voltage drop
• Power factor correction by synchronous motor
• Power factor correction by capacitors
• Functions of the capacitor in raising voltage
• Potential high voltage hazard of permanently connected capacitors
• Switched capacitors; control parameters