Impedance Response Characteristics of Synchronizer under Wide Frequency

With the increasing number of power electronic devices and renewable energy units in the power network, wide frequency oscillation accidents occur frequently in China and abroad. The oscillation frequency covers several hertz to several thousand hertz, which causes great harm to the safe and stable operation of the units. As the most important equipment in power grid, the safety and stability of synchronous generator under wide frequency is very important. In this paper, the response of synchronous generator as load to wide frequency oscillation is studied, and the formula for calculating the impedance of synchronous generator is deduced and verified. Then the reason of shaft torsional vibration caused by synchronous generator as oscillation source is introduced, and the equivalent impedance response characteristic of synchronous generator at this time is given.