The impacts of distributed generation using high speed wind turbines on power system transient stability

Abstract

Wind power generation source differs in several respects from conventional sources of energy like hydro and thermal. Furthermore, wind generators are usually based on different generator technologies other than the conventional synchronous generators. The stochastic nature of wind, makes it very difficult to control the generator power output. Most wind turbines are based on induction generators which consume reactive power just like induction motors during system contingency, which in turn deteriorates the local grid stability. This paper proposes to study and analyze the impact of distributed generation using high speed wind turbines on power systems transient stability. This is achieved using a simplified model of the IEEE 30 bus system which replicates the Kenyan grid system. The base line case simulations were carried out using Dig SILENT Power factory version 14.0 software and results recorded. Thereafter, a Double Fed Induction Generator (DFIG) model was integrated to the system and various faults introduced in the system. The results showed that, the addition of the DFIGs to a power system network, does not negatively affect the stability of the system. It was evident that even with increased penetration of wind power up to 10.2%, the system showed a high degree of transient stability. Consequently, from the simulation results, as the system approaches stability, the swings are more or less of equal magnitude. As the penetration level of DFIGs increased from 0% to 10.2%, the critical clearing time also increased. This clearly shows that the transient stability of the power system is improved by DFIG penetration in the power network.