Experiment No:
02
Experiment Name:
Performance of Transmission Line under Different Loading Condition.
Objectives:
I. To measure and analyze the voltage drop across the transmission line at varying
load levels.
II. To understand the quantify power loses occurring in the transmission line under
different loading scenarios, helping to understand the line’s efficiency.
III. To observe the line’s current carrying capability under different loading
condition.
IV. To observe how the loading affects the maximum power transmission capability.
Theory:
The performance of a transmission line varies significantly based on the type of load
it is supplying, such as resistive, capacitive, or inductive. Under a resistive load
condition, where the current and voltage are in phase, the power factor is unity,
leading to high efficiency with minimal voltage drop. The I²R losses are low, and
the voltage regulation is stable, making this load type the most efficient for
transmission. On the other hand, capacitive loads, where the current leads the
voltage, can result in a leading power factor and cause overvoltage issues,
particularly due to the Ferranti effect in lightly loaded or no-load conditions.
Although the power losses are generally lower than in inductive loads, reactive
power compensation is required to prevent voltage instability. In contrast, inductive
loads cause the current to lag the voltage, leading to a lagging power factor and a
significant voltage drop due to the inductive reactance of the transmission line. The
higher current drawn by inductive loads increases I²R losses, reducing system
efficiency and necessitating compensation with capacitors to improve voltage
regulation. In summary, resistive loads offer optimal performance, while capacitive
and inductive loads require careful management of reactive power to maintain stable
operation and minimize losses in the transmission line.
Equipment List:
Description Model
Three Phase Transmission Line Lab Volt- 8329
Resistive Load Lab Volt- 8311
Inductive Load Lab Volt- 8321
Capacitive Load Lab Volt- 8331
Ac Voltmeter Lab Volt- 8426
Three Phase Wattmeter/Varmeter Lab Volt- 8446
Phase Meter Lab Volt- 8451
Power Supply Lab Volt- 8821
Connection Leads Lab Volt- 8951
Circuit Diagram:
Discussion:
The performance of a transmission line under different loading conditions resistive,
capacitive, and inductive demonstrates the varying impacts these loads have on
power factor, voltage regulation, and overall system efficiency. A resistive load
provides the most stable and efficient operation, with minimal voltage drop and low
power losses. Capacitive loads, while lower in losses, can cause overvoltage issues
that require compensation to maintain voltage stability. Inductive loads present
challenges due to significant voltage drops and increased power losses, demanding
corrective measures such as capacitors to improve voltage regulation. Understanding
these variations is crucial for optimizing transmission line performance and ensuring
reliable power delivery across different load conditions.
Experiment No:
03
Experiment Name:
Parameters which affect Real and Reactive Power Flow.
Objectives:
I. To observe reactive power flow when sender and receiver voltages are different,
but in phase.
II. To observe reactive power flow when sender and receiver voltages are equal, but
out of phase.
III. To observe reactive power flow when sender and receiver voltages are different
and out of phase.
Theory:
The real and reactive power flow in a transmission line is influenced by several key
parameters, which impact the efficiency and stability of power transmission. The
line impedance, consisting of resistance and reactance, plays a crucial role, with
resistance leading to real power losses (I²R losses) and inductive reactance
increasing the reactive power requirement. Voltage levels at the sending and
receiving ends, as well as the power angle (δ) between them, affect both real and
reactive power flow, with larger voltage differences and power angles leading to
higher real power transmission. The power factor, or the ratio of real to apparent
power, also affects these flows, with lower power factors indicating more reactive
power and reducing real power transmission efficiency. The length of the
transmission line increases resistance and inductance, which in turn raises both real
power losses and reactive power demands, requiring compensation measures. The
type of load, whether resistive, inductive, or capacitive, significantly impacts the
power flow, with inductive loads demanding more reactive power and capacitive
loads potentially supplying it. Transmission line capacity, including thermal limits,
also determines the amount of current and power the line can handle without
overheating. Additionally, reactive power compensation devices, such as shunt and
series capacitors or reactors, and transformer tap settings, can regulate voltage levels
and improve both real and reactive power flow. Finally, weather and environmental
factors like temperature, wind, and humidity can influence line impedance and
thermal limits, further affecting power flow. Managing these parameters effectively
ensures reliable and efficient transmission of power across the system.
Equipment List:
Description Model
Three Phase Transmission Line Lab Volt- 8329
Resistive Load Lab Volt- 8311
Inductive Load Lab Volt- 8321
Capacitive Load Lab Volt- 8331
Ac Voltmeter Lab Volt- 8426
Three Phase Wattmeter/Varmeter Lab Volt- 8446
Phase Meter Lab Volt- 8451
Power Supply Lab Volt- 8821
Connection Leads Lab Volt- 8951
Circuit Diagram:
Discussion:
The study of real and reactive power flow in a transmission line reveals that multiple
parameters significantly influence the efficiency, stability, and performance of
power transmission systems. Factors such as line impedance, voltage levels, power
angle, power factor, and line length all play crucial roles in determining the amount
of real and reactive power that can be transmitted effectively. The nature of the load,
transmission line capacity, and environmental conditions further impact power flow,
highlighting the importance of careful management of these parameters. By utilizing
reactive power compensation devices and voltage regulation techniques, power
losses can be minimized, and voltage stability can be maintained. Understanding
these variables is essential for optimizing transmission line performance and
ensuring reliable power delivery under various operating conditions. This lab
experiment has provided valuable insights into the complexities of power
transmission and the critical need for precise control of both real and reactive power
flow in electrical systems.
