Steady State Characteristic Analysis Of FPC And Its Synergetic Control

The multi-functional Flexible Power Conditioner (FPC) is a new kind of FACTS device, which consists of a doubly fed induction generator (DFIG) and a voltage-source pulse width modulation (PWM) rectifier-inverter combination used as an AC exciter. As the FPC has the capability to possess independently the regulation of both the reactive power and the dynamic active power; it is able to enhance power system stability and improve power quality.A general overview of the energy storing technology is presented at first, then the background and development of FPC is proposed. A brief introduction of the basic topology and the operation principles of FPC are given.FPC regulates active and reactive power by means of AC excitation control, so that its power output margin is limited by the frequency converter at rotor side. The influence of limitation of frequency converter's current, voltage and capacity on power out margin of the FPC as well as the relationship between the power output margin and the slippage are investigated. Research results show that the main restraint condition of FPC's power out margin is the current limitation of the frequency converter. In addition, selection of optimal operation condition of FPC under steady state is also analyzed.A kind of nonlinear control theory, synergetic control, is introduced for the FPC. Its basic principle is discussed in detail. Then the characteristics of the synergetic control and the advantages of the control are shown. Then, location of application as well as the control strategy of the FPC are discussed. A new controller is designed according based on the synergetic control. Simulation results show that the designed systems are able to resist disturbance and to enhance the stability of the power system.