Coordinated Control Of Non-ideal STATCOM Of Facts Devices And Generator Excitation

Power system is a dynamic, multidimensional, strongly nonlinear system, grid interconnection is the inevitable trend of modern power. As the important pillar industry of the national economy, it is very important to ensure the reliable and stable operation of the power systema, the commonly used power system stability control law is introduced in this paper.With the extensive application of FACTS, the more economic and efficient power grid has been achieved, while lots negative factors are brought to the security of modern systems. The application of FACTS controllers has great potential applications, which can greatly improve the stability of the grid voltage and the transmission capacity, but also effectively reduce grid losses and the low frequency oscillation. The development status of modern power system, and the operating principle, the mathematical model, as well as research achievements of widely used FACTS controllers, including TCSC, SVC, STATCOM and UPFC, are introduced in this paper. As core device of FACTS, STATCOM, with small size, low-voltage characteristics, and fast response, is the research hotspot in the reactive power control areas currently.As the traditional control measures, the generator exciter can regulate the power allocation, improve the protection sensitivity, as well as maintain the system stability. Excitation system includes excitation devices and excitation power supply, and the development of DC excitation is earlier, but has been gradually replaced by AC excitation, which has unlimited capacity, free from outside interference, and reliable operation, currently, the most widely used mode is the self-shunt excitation. Focusing on the single machine infinite system, the modeling, the analysis and the design of the excitation model are introduced in this paper.Coordinated control of generator exciter and FACTS devices has great significance, the above theme is studied systematically in this paper. Previous studies are based on the ideal state on the STATCOM, this paper analyzes the complexity of controlling the detailed model of salient-pole generators when the phase difference of the point voltage and current where STATCOM is accessed is at arbitrary ? instead of the ideal state at 90. By establishing the nonlinear system model with algebraic constraint equations of one salient-pole generator and STATCOM, and the detail control method of the excitation and STATCOM devices is designed by using geometric feedback linearization control theory combined with classical linear quadratic optimal control method. The method of design improves the practicality of coordinated control of excitation and STATCOM, meanwhile, the effectiveness of the control is proved by simulation waveform using MATLAB, which makes up for the lack of the technology research of controlling salient-pole generator excitation and STATCOM coordinately.