The Voltage Stability Strategy Of Self-excited Induction Generator Based On Predictive Current Control

In recent years,more attention to renewable energy power generation,such as wind energy and hydropower,which has been increasing demand in world energy,particularly in poor and remote areas.And Self-excited induction generator(SEIG)system which depends on the advantages,such as compact size,light weight,low cost,simple and strong structure,and high reliability,has widely application and high economic benefits in the independent power generation system.self-excited voltage build-up became an independent power system and provides power for load,through the interaction of rotor flux and parallel capacitor when it is under a certain speed.But the SEIG has poor load-carrying capacity and is unable to regulating voltage continuously,so it cannot maintaining voltage stability just relying on capacitance excitation,the voltage fluctuates due to the different load and speed.In the most severe cases,the voltage even collapse,and its power quality cannot be guaranteed,so real-time dynamic reactive power compensation needed to the SEIG.In a wide range of voltage regulation and reactive power compensation,the static synchronous compensator(STATCOM)is widely used in the control of the SEIG due to its rapid dynamic response,the reactive power compensation based on STATCOM paralleling system is designed to improve the ability of reactive power continuous regulation,to realize the constant terminal voltage control and the improvement of power quality.In order to achieve the SEIG voltage stability control.Firstly,set up the mathematical model of SEIG,through simulation analysis the voltage wave of the SEIG in no-load and load operation,and validated it on the dSPACE experimental platform.The SEIG based on STATCOM paralleling system,Dealing with the double closed loop control system—voltage outer loop using PI control and the current inner loop using predictive current control,and compared with terminal voltage wave under the traditional PI control.Simulation and experimental results show that,through the double closed loop control of STATCOM can realize the voltage stability control in three-phase symmetrical load or dynamic load.At the same time,in order to solve the voltage stability problem under three-phase asymmetric load,decoupled double synchronous reference frame PLL(DDSFR-SPLL)can detection and control phase.Not only ensuring a good dynamic response,but also solving the problem of the three-phase unbalanced voltage phase lock,Eventually realize accurate detection voltage phase and voltage stability.