Optimal Placement of Time Flexible Supplier's Block Bid in a Day-Ahead Electric Market using Genetic Algorithm

Electric power supplier using thermal generator submits block bid in a Day-Ahead Electricity Market to compensate for high startup and shut down cost. Flexi type Block Bid is a special kind of Block Bid, currently used in Nord Pool, have flexible execution time set by Power Exchange (PX) based on Social Welfare maximization. The optimal placing of block bid execution time is an NP-hard combinatorial optimization problem whose solution is difficult to obtain using repeated application of Mixed Integer Linear Programming algorithm in polynomial time. Therefore this work formulates the optimal placement of suppliers block bid in a Day-Ahead Electricity Market as an optimization problem and solve using Genetic Algorithm. Social welfare for 24 hours of next day called social welfare volume has been used as an objective function to maximize. Computer simulation was performed using MATLAB with hourly electric power demand randomly generated as per the typical hourly power demand curve in Indian power system. Two types of Block Bid are considered for simulation, the first one in which length of the block is fixed and second one in which length of block bid can vary from fixed minimum to fixed maximum. Simulation result clearly shows that there is a significant increase in social welfare volume and hourly Market Clearing Volume and a significant decrease in Hourly Market Clearing Price for both the cases.