电机学电机学电机学 (42).ppt

Electrical MachinerySteady-State Stability in Parallel Operation7.5.2 Steady-State Stability in Parallel OperationSteady-State Stability in Parallel OperationThe running status of the running synchronous generator in parallel connection with the power grid varies when tiny disturbance takes place on the power grid or the prime mover,and could the generator return to the previous status when the disturbance disappears?1=+0When the torque balance is balanced7.5.2 Steady-State Stability in Parallel OperationAbout acceleration and speeding down of the generatorWe know from above analysis that the rotating speed of the rotor keeps unchanging(understood in this way:driving force is equal to resistance)when initially the generator is in balance status(PT=Pem,in which PT=P1-P0,called effective mechanical power);When increase the mechanical power input to make PTPem,the rotor will speed up and the power angle will increase(understood in this way:driving force is bigger than resistance).When increase the mechanical power input to make PT180,180,out of step Point b is of Steady-state instability090180THANKS FOR WATCHING!