Dual mode characteristics and grid-connection schemes with two different structure micro turbines are compared. Firstly， the system structure， controller， dual mode operating schemes and the influence on the traditional system protection are compared. The dynamical characteristics are compared via simulating different 10 kV line faults. The results indicate that type II micro turbine contributes larger short circuit currents， which has worse influence on the upper level protection scheme and equipment specifications. Furthermore， type II turbine needs more rigid mode changeover conditions. Type I turbine cannot change over seamlessly， but has less influences by other 11kV line faults when connected， and contributes less short circuit currents.