Load Frequency Control for Transmission Congestion Management using Price Area Concept

The deregulation of the power industry splits the single company which controls all the functions like generation, transmission, and distribution into smaller entities based on their functions. These entities compete in the open market auction by placing their offers and bids to an independent operator, who clears the market such that quality power is given to customers at a lower cost while ensuring maximum profits for the market players. Hence in-merit GENCOs generate the allotted power which is then used to fulfill the contracted demand of the in-merit DISCOs. The percentage of power that each GENCO needs to deliver to match the demand of a DISCO is given by area participation factor which forms an area participation matrix for all the GENCOs in an area. The automatic generation control in the GENCO uses this matrix to generate the contracted power and maintain the system within stability limits. Congestion occurs when excess power is transferred between areas to meet the contracted demand. Price Area Congestion Management relieves this congestion without affecting the economics of the system, by clearing the market with different price for each area instead of common price. In this paper, a control strategy for price congestion concept was developed and incorporated with the two-area model of a deregulated power system. The responses from the resulting model show that with the addition of the price area congestion concept, the transmission limit is maintained, without affecting the market players present in the system.