Load frequency control with MWh constraint and regulation margin

To improve the conventional frequency and tie-line power regulation, a tie-line bias control (TBC) based control scheme is presented in this paper. An additional control loop is set to the conventional TBC control loop to satisfy the MWh constraint and also to satisfy the regulation margin. By the additional control loop, the MWh through the tie-line is kept to its contract MWh not to violate the contract for power accommodation, and the required capacity for the LFC is always maintained to a certain extent even after having quite large load increase. In addition, the required fuel cost for the load-frequency regulation is evaluated.