Thesis Purpose

1
Simulating voltage collapse phenomena and
investigating different mitigation techniques for
a complex power system
Author Richard Laws Supervisor Dr Tapan Saha

• Thesis Purpose
• The aim of this thesis was to simulate static and
  dynamic voltage collapse and investigating
  different mitigation techniques for a complex
  system. All of the simulations was carried out on
  the 14 bus IEEE test case. Simulations were
  performed using the PowerWorld and Power factory
  software.

• Mitigation Techniques and indices
• Voltage collapse was predicted and mitigated
  using the following tools
• and indices
• Static
• PV and QV curves
• Load Margins
• Sensitivity Analysis
• Reactive compensation

• Dynamic
• Reactive compensation
• Control actions of power
• system (VCO, PSS, LTC)
• Load shedding
  

14 Bus Power Flow Test Case
Reactive Power Margin

• What is Voltage Collapse ?
• Voltage collapse occurs in heavily loaded systems
  or systems with long lines (or with both) under
  the following conditions
• Reactive power available from capacitors,
  generators and SVSs falls below system reactive
  losses and loads, or
• Reactive power sources do not greatly exceed
  reactive losses and loads, and voltages are
  allowed to drop.
• These conditions are usually arise following the
  trip of a line or generator, or a combination of
  equipment outages. However, an unusually high
  peak load or lesser disturbances can cause
  voltage collapse.

VQ Sensitivity
Control Response of System
Simulation Results and Conclusions Voltage
collapse can be prevented when appropriate
preventive and corrective control are determined.
Using simulation to study the voltage collapse
phenomena is an effective and inexpensive method
in terms of time, equipment and cost.