Fundamental Study of Small-Signal Stability of Hybrid Power Systems

In the modern world, the load demands on the electrical grids are increasing at a very high rate. Due to increasing power demands and deregulation of the electrical power, the power systems are operated to their maximum capacities.Many renewable sources are integrated to the conventional grids to meet the increasing load demands. The HVDC technology has provided an efficient way to integrate different renewable sources successfully to fulfil the electrical power requirements. The integration involves incorporating different types of machines with different mechanisms and technologies. At peak load operating conditions, the electro–mechanical modes of oscillations exist between different parts of the system, which possess serious threat to the operations leading to widespread blackouts. These modes depend on various factors like, loading conditions, weak tie–lines, type of faults, topology of the system and generators. Among these, one of the key factors that affect the system stability is the machine inertias. The stability of the system is a key issue to be addressed when different sources are incorporated into a huge system.In this thesis work, the effect of incorporating different inertia machines on the small signal stability of the system is addressed. Two study cases are studied to examine the effect of machine inertia on the system stability, case–1 is a HVAC system and case–2 is a HVAC–DC system. Two methods are used to access the stability of the system, by linearized models and by signal record based approach. The results from the linearized models are compared with the result obtained from the information extracted from the measured signals.Electrical Engineering | Sustainable Energy Technolog