Transient stability enhancement of multi-machine power system by novel braking resistor models

Braking resistor (BR) is one of the effective methods to enhance 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 indices, number of components used, heat loss, harmonics, and cost 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 faults in the IEEE-9 bus power grid system. Simulation results indicate that the transient stability performance of the proposed BR methods is comparable to that of the existing BR model. Moreover, the proposed models use a single unit of BR that might lead to cost reduction. Therefore, the proposed BR models can be considered as an alternative to the existing BR model for improving the transient stability of multi-machine power system.