Novel braking resistor models for transient stability enhancement in power grid system

Braking resistor (BR) is one of the effective methods to improve the transient stability of synchronous generators. In this work, two new braking resistor models, one consisting of thyristor rectifier and the other consisting of a combination of diode rectifier and chopper, are proposed, and their performance is compared with the existing thyristor controlled braking resistor. Comparison is made in terms of the speed performance indices, number of components used, heat loss and harmonics analysis for each proposed model and the existing model. The effectiveness of the proposed methodology is tested through Matlab/Simulink simulations considering both balanced and unbalanced temporary and permanent faults in a single generator power grid system. Simulation results indicate that the transient stability performance of the proposed methods is comparable to that of the existing model. Moreover, the proposed models use a single unit of BR that might lead to cost reduction of BR. Therefore, the proposed models can be considered as an alternative to the existing model for improving the transient stability of the power system.