Damping Control of Inter-area Oscillation in Ultra High Voltage Power Grid Based on Unit Optimal Rescheduling

Abstract

Along with the construction of ultra-high voltage power grid, low frequency oscillation problems become more and more serious. Thus, it is very significant to improve inter-area mode damping for the purpose of preventive control. Ultra-high voltage power grid is interconnection of multiple large regional power grids and there may be multiple weak damping inter-area oscillation modes. Therefore, it needs to consider the effects of multiple inter-area modes for power oscillation preventive control of ultra-high voltage power grid. At first, according to damping ratio sensitivity in weak damping mode, the rescheduling control units are selected. Then, the objective function of improving the system damping only considering a single weak damping mode is established and the genetic algorithm is adopted to optimize the unit active power for obtaining optimal control measures. Finally, aiming at multiple weak damping modes of the ultra-high voltage power grid, a multi-objective model to improve the damping of multiple weak damping oscillation modes based on mean square error is put forward. The multi-objective model improves damping of multiple inter-area oscillation modes by adjusting active power of units as preventive control of low frequency oscillation in ultra-high voltage power grid. The multi-objective optimization method is applied to New England 10-machine 39-bus system for comparative analysis, which verifies the feasibility and effectiveness of it.