Steadiness Test of Consecutive Power Flow by Means of Electric Load Reduction

Abstract

The primary objective of this thesis is to investigate & study the transient steadiness of a Single Machine Infinite Bus (SMIB) system. The objective is due to the fact that the most desirable quality of an AC power Bus is steadiness. The definition of steadiness in this context is defined as the ability of the Bus to hold both the supply voltage & the voltage frequency to a constant value. In real life Power Bus, the value of frequency rarely changes, but value of voltage changes all the time. When power supply is less than the operating load, the frequency also reduces. The voltage changes may be due to the short comings of the power Bus & its relevant systems, the inability of the generators to provide enough power or due to the intensity of the load on the Bus. This thesis assumes the power Bus to be ideal i.e. no loss & also assumes that the generators are of sufficient capacity. Therefore only manipulative variable is the load. During the research, theoretical models for the relevant systems & sub systems were generated. Practical implementation of the said research is currently out of scope due to technical reasons e.g. the Bus bar works at 130 kv. Simulation models include generator model, load models (both static & dynamic) and reduced network model. The theoretical prediction is that steadiness can be improved via load curtailment. This prediction is tested during simulation. Before simulation a SMIB system is modelled with a load & infinite Bus. For the simulation fault points are designated at multiple points, one is explored at a time. Fault points include the secondary of power transformer, at the infinite Bus node & at the transmission node. The effect of fault is noted at the generator rotor angle & at the output power. Based on the result, multiple modes of curtailment are proposed that can help steadiness