Research On Robust Control Strategy To Dampin Inter-area Low Frequency Oscillation In The Complicated Power Systems

China’s energy resources and energy demand is reverse distributed, high voltage transmission network which is cross-regional, long-distance and large-capacity has being built, the construction of strong and smart power grid proposed new requirements to the interconnection between different regional grid. In circumstances of heavy-duty, inter-area low-frequency oscillation is likely to happen on these tie-lines, inhibiting the low-frequency oscillation effectively is of great significance to the safe and stable operation of the grid.Traditional control methods are difficult to adapt to the uncertainties in power system, including a variety of faults, inaccurate system parameters and operation mode changes. There are three types of control methods with robustness for uncertainties:robust control, sliding mode control and adaptive control.Firstly, conservatism improved robust H2/H∞control method is used to design the controller in this paper, in order to achieve robust control with less conservatism and taking the effect of uncertainties into account. On the basis, taking into account that the sliding mode in sliding control has full robustness for matched uncertainties, an integral controller based on controller can adapt to this type of uncertainty to some extent. Sliding mode control have complete robustness for matched uncertainty on sliding mode, based on improved conservatism robust control is designed. The design of the former control method, an integral sliding mode controller is designed to and the performance of the controller is improved.Through mapping the complex plane, collocated control method achieve a configuration of closed-loop system poles in a nonconvex domain. The closed-loop system will not introduce negative damping to the system. With the combination of collocated control and robust control, a collocated control based robust controller is designed. At last, an adaptive integral sliding mode controller has been designed based on this method.Each method is validated by the simulation using IEEE four machine two area system, the controllers on different devices all have strong robustness.