Switching Governor Based Transient Stability Control of Multi-Machine Power Systems

This paper proposes a bang-bang funnel controller based switching governor for improving the transient stability of multi-machine power systems. The proposed governor consists of three parts: a second-order bang-bang constant funnel controller(BBCFC), a conventional speed control loop and a properly designed switching strategy. The switching strategy will activate the BBCFC to restrict the speed of synchronous generator(SG), as well as its first-order derivative with respect to time, within prescribed funnels when severe faults occur in power systems. If the deviation between the speed of SG and synchronous speed is small, then the conventional speed control loop will be selected to guarantee the convergence of the speed of SG to synchronous speed. Compared with traditional governors, the control effort of the proposed governor is much larger, which enables the rapid adjustment of control valve flow area so that the mechanical power input can be changed in time to stabilize the speed of SG. Simulation studies are carried out on a 12 machines power system to test the performances of the proposed switching governor.