Evaluation of Optimal Capacity Benefit Margin on Tie Line between Control Areas

H. Kuraishi and A. Yokoyama (Japan)


Available Transmission Capability (ATC), Capacity Benefit Margin (CBM), power system, reliability, reserved capacity, tie line.


In order to maintain power supply reliability at a certain level, each power company has to keep its appropriate reserved capacity. When a generator outage or an unexpected large power demand occurs, power shortage can be avoided if power company has enough reserved capacity. Normally, this reserved capacity is not used except in case of emergency, and is often regarded as a surplus plant. To reduce the reserved capacity in each area, tie lines between control areas has a reserved margin to allow power exchange between them in case of unexpected events. For example, when a generator outage occurs in a control area and the power company cannot supply all power demand, the power will be supplied from its adjacent companies through the tie lines. Consequently, power shortage in this area will be avoided. This margin for the power exchange is called Capacity Benefit Margin (CBM). By reserving CBM on tie lines, reserved capacity in each control area can be reduced. In this study, a calculation method of an optimal CBM on tie lines is proposed. Then, numerical results for the optimal CBM and the reduced reserved capacity in each control area are shown for the test system.

Important Links:

Go Back