Research On Islanding Protection And Control Strategy Of Micro-grid

Nowadays, here is a research on distributed generation which seems to beefficient and dependable. The micro-grid is one of method which based on distributedgeneration. However, there seem to have new challenges in the operation of the gridsince the introduction of distributed generation, such as islanding protection. Island isa uncontrollable network as the system once disconnect from the main network whiledistributed generation are still providing power. In this paper, the mainly research isislanding protection and control for Micro-grid.This paper does an in-depth analysis and discussion about the application ofalgorithm basing on Kalman filter. This article introduces the basic principle of theSimulink/Stateflow simulation, realizes Kalman filter by Stateflow, modules thealgorithm, and the algorithm module can be operated synchronously with Simulinkmodule. The development process is visualized, can by flow chart to show theprogramming, and the logic is clear at the same time. Stateflow can clearly observethe moving process the program, and lighten the burden of adjustment.This paper presents a new method to detect islanding based on Frequencystandard deviation and a new reactive power disturbance method based on Triangularwave. Finally, this paper realizes the new method by Simulink/Stateflow. In addition,this paper presents the frequency standard deviation as the reliable criterion forislanding protection, which reduces the non-detection zone, and frequency rate changeas the pick-up condition of active islanding detection, which solves thesynchronization problem of power disturbances. Finally, a simulation model ofmicro-grid system is built in Simulink, verifying the correctness of theoreticalanalysis as well as the validity disturbance detection method based on reactive power,and this method is validated in the Smart Grid Laboratory of Tianjin University.