Bicriterion optimisation for traction substations in mass rapid transit systems using genetic algorithm

In modern mass rapid transit systems trains are often equipped with regenerative braking. Effective control of firing angles at traction substations (TSS) will bring about high recovery of regenerated power, even load sharing among TSS and thus economic returns. These two objectives of high power recovery and even load sharing are conflicting, and do not reach their optima simultaneously. A tradeoff approach is proposed for optimising these two objectives and for compromising with other objectives using a genetic algorithm. Consistent power saving has been obtained from optimisation results and load sharing can be greatly improved through coordinated optimisation of TSS firing angles. The optimisation presented is carried out at a particular ‘snap shot’. The proposed approach is being extended to a time period for dealing with overall energy recovery.