Optimal control of superconducting magnetic energy storage unit

ABSTRACT A study of power system transient stability enhancement through effective use of superconducting magnetic energy storage unit is presented. Simultaneous optimal control of active and reactive power is formulated as the control which forces the fastest dissipation of power system energy involved by a fault in transmission network. Optimal control strategy is obtained from direct Lyapunov method. It requires control signals based on state variables locally not available at the bus where energy storage unit is installed. It is proved that these optimal control signals can be replaced by the time derivative of two electric quantities derived from local measurements. Control algorithm based on these quantities gives smooth and very effective regulation, tests clone for two-machine system have confirmed validity and robustness of the proposed new control algorithm.