Home SEEE Student Project Page
PWM Controlled Static VAR Compensator

This project aims to provide control and stabilize receiving end voltage in the areas of high load growth, of high voltage power transmission network. By considering the fact that, when fully loaded long length high voltage transmission line is suddenly rejected its full load, the receiving end voltage increases significantly (due to shunt parameter + generated leading VAR in the High Voltage network), it's impact will strikes to the receiving end sub-station devices & can be cascaded to the nearest power plant, results crossing of over voltage limits is IBM power plant & that plant will trip first & next nearest plant will trips & so on ... the entire grid may  catastrophically collapse. If there is no reactive power compensation device installed at the receiving end, such problem may arises frequently, which is a great challenge from the power system stability stand point. However, in case of heavily loaded conditions of the high voltage transmission line (most of the loads are inductive & resistive in nature) the receiving end voltage may decrease below the permissible limits, and this can be improved by connecting shunt capacitors into the receiving end.

The Static VAR Compensator is basically power electronics devices that provide fast-acting reactive power compensation on high-voltage transmission networks as and when required. SVC technology increases transmission capacity and stabilizes power supply voltage and is a vital part of the transmission system for maintaining reliability, and stability of power system network during various system conditions. This project is basically consists of an equivalent model of 400KV 300 KM long transmission line as per its standards equivalent line parameters. The type of compensator we have selected in this project is fixed capacitor, thyristors (TRIAC) Controlled Reactor.

The Proportional Controller is designed as per the characteristics shown by the model of the transmission line. The phase angle control approach for the inductive VAR compensator is implemented by using Pulse Width Modulation control technique. However, capacitive VAR compensator is fixed. In this controller if the terminal voltage at the receiving end is increased above its safe operating limits (full load rejected case) full cycle of AC will be automatically connected to the inductive VAR compensator through bidirectional conducting thyristors (TRIAC), this will consume available leading VAR in the high voltage grid. However, when the grid is loaded by its usual load partially the cycle of AC will connected to the inductive VAR compensator & finally when line is fully loaded inductive VAR compensator will be completely rejected from the system, hence process will be repeated as & when required. This is how this controller will control & monitor the receiving end voltage by using a SVC technology.


  •     Om Prakash Pokharel
  •     Ramesh Khadka
 

Course of Study

Course of Study

Project Page

Project Page

Feedback

Feedback

Click HERE to give feedbacks and comments on the site!

Encipher

Encipher 2009Download the technical journal, Encipher, published annually by SEEE.