Robust Stability Control For STATCOM And Generator Excitation Based On Dissipative System Theory

Power system is a typical high dimensional nonlinear dynamic system. The development of large interconnected power systems, which enhance the complexity of power systems and nonlinear level. On the other hand, with the development of power electronics technology and the exaltation of computing capabilities, more and more new technology, new equipment and new strategies are used in power system. STATCOM as flexible AC transmission systems, a new device has been widely used in the power system, so it can effectively improve the system transmission capacity, enhance system stability and improve power quality, but also increases the complexity of the system and control issue. Therefore, power system stability analysis is one of the important tasks in planning and running. To improve power system stability, in addition to a reasonable response to network planning, construction to take the necessary measures, the most important is to take the effective control means for relevant part. Therefore, the control design study for STATCOM and power system excitation has great significance.In order to improve power system stability control technology, a lot of research work has been done for the system model and control method. Generator excitation control improve power system stability ,which has always been the one of most stable and economically effective means, but most excitation control system are designed based on the power system operating point in a linear model to obtain linear control design Law. In the actual operation of power systems, due to the existence of various uncertainties and we should reduce the impact of interference, which, has a great impact on the control system and the input disturbance has a small enough impact for the system output, it also is the problem of the power system robust nonlinear control, which has a great significance to improve stability and the system dynamic. In addition, the continuous development of the Dissipative Systems Principle provides a new perspective and method to analysis the power system, therefore, nonlinear controller design of power systems is necessary, based on principles of dissipative system, fully considered the nonlinear characteristics of power system.In this paper, the appropriate mathematical model is created and derived using the basic principles of nonlinear control and control methods, combined with the characteristics of power systems for various system devices for a STATCOM and generator excitation system. Then, the coordinated controller of STATCOM and generator excitation is devised, which maintain system power angle and voltage stability according to the thought of Passive coordination control and backstepping.Finally, the basic concepts of differential algebra are introduced and extended results of previous studies to nonlinear differential algebraic systems, which describe the dynamic behavior of the complex power system. We will extend single model to multi machine power systems and establish the structure remains uncertain power system model reflecting the topological characteristics of the system.