Interview Questions: Hydroelectric Power Plant 1

What are the essential elements of the hydroelectric power plant ?

Answer: Some of the essential elements of hydroelectric power plant are:

(1).Catchment area (2).Reservoir (3).Dam (4).Spillways (5).Conducts (6).Surge tanks (7).Draft Tubes (8).Power House (9).Switchyard for transmission of power

 What is the significance of Dam ?

Answer: Dam performs the following tow basic functions

• It develops a reservoir of the desired capacity to store water
• It builds up the head for power generation.

What is Hydrograph  and its significance?

Answer: Hydrograph is a graphical representation between the discharge or flow with time. It is plotted with flow as ordinates (Y-axis)  and time intervals as abscissas ( X-axis). The ordinates may be plotted in terms of the gauge height, the number of cubic meters per second per square kilometer, the power in kW that can be developed. The abscissas may be taken in terms of hours, days, weeks or months. It also indicates the power available from the stream at different times of the day or year (particular period). Hydrograph is similar to load curve and used to study the electric power.

A Hydrograph provides the following information:

• The discharge at any time during the period under consideration
• The maximum and minimum runoff during  the period
• The average run-off during the period
• Total volume of the discharge up to any time, given by the area under the curve up to that time

What is the use of Spillway?

Answer: When the water level in the reservoir basin rises, the stability of the dam structure is endangered. To relieve the reservoir of this excess water, a structure is provided in the body of the dam. This structure is called spillway.This is constructed to act as safety value. This provides structural stability of the dam under conditions of the floods without rising the reservoir level above High Flood Level.

What is Mass Curve?

Answer: Mass curve indicates the total volume of run-off in m³ up to certain time. The abscissae may be day, month or year. This curve is obtained from the records of average monthly flow. The slope of curve at any point gives the rate of flow at that time. These curves are used to determine the capacity of the storage reservoirs for hydro projects.