•
The technique used to determine how independent variable values
will impact a particular dependent variable under a given set of
assumptions is defined as
sensitive analysis
. It’s usage will depend
on one or more input variables within the specific boundaries, such
as the effect that changes in interest rates will have on a bond’s price.

•
It is also known as the what – if analysis. Sensitivity analysis can be used for
any activity or system.
•
It helps in analyzing how sensitive the output is, by the changes in one
input while keeping the other inputs constant.

•
Let the base case inputs of the equation be:
•
Z
a
= 20m
Z
b
= 5m
•
P
a
= 24 000
P
b
= 23 000
•
U
a
= 50
U
b
= 45
•
Then;
•
Assume uniform velocity distribution in the pipeline or waterway and;
•
p
= 1000
g = 9.81

•
Therefore the equation yields to

PERFORMANCE
TESTING

Objective:
In broad terms, the objective of the performance testing of SHP
stations can be stated as under:
(i) To verify that all parts, systems and auxiliaries in the power
station are performing their assigned functions correctly.
(ii) To verify that the generating units in the plant are operating
at or above the
prescribed efficiency value.
The objective of (i) is to check the qualitative working of the power
plant, while that of (ii) is to find out whether the generating units
meet the mandated efficiency requirements.

Performance Test
There are 2 main types of test done on a Mini Hydro Power plant :
1.) Maximum Power Output Test
2.) Unit Efficiency Test

General Methods of Power Measuremet
The power output from the turbine shaft may be measured by one of the
following primary methods:
1.
Mechanical Brake
2.
Water Brake
3.
Electrical Brake
4.
Torsion Dynamometer
All the above methods involve the simultaneous measurement of net Torque(in
mkg) and Shaft Speed(in rev/min) from which the net power output in KW
from the turbine shaft may be computed from the following expression:
P = 2πNT/60

In methods 1), 2) and 3), the torque on the brake is determine by the effective force
applied to the brake arm and the radius at which it is applied. In method 4), the
torque must be computed by means of a previous calibration.
TORQUE MEASUREMENT
Water Break
-the water or Froude Brake consists of a bladed disk fixed to the shaft, and
rotating inside a casing filled with water or oil and able to pivot about the shaft axis.
The torque is varied by altering the amount of liquid in the casing . It thus absorbs
power hydro dynamically, the torque reaction being measured on the pivoting casing.

UNIT EFFECIENCY TEST
•
Unit Efficiency Test The test aims at determining the actual efficiency of the
generating unit(s) under specified conditions. This is the most difficult and time-
consuming test in the whole exercise of performance testing of a power station. The
efficiency of a turbine-generator unit is given by the ratio of the electrical power
output of the generator to the hydroelectric power input to the turbine. The latter is
equal to the product of the net water head availed by the turbine, the discharge rate

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- Summer '16
- Llorando
- Hydro Power Plant