Research On Thermal Performance Of Stator And Rotor Of Synchronous Condenser Under System Fault

The Synchronous Condenser(SC)installed in UHVDC converter station can respond quickly under system fault,provide dynamic reactive power support for the system,reduce voltage fluctuation and prevent commutation failure.However,the large current and reactive power lead to the increase of loss and heat,thus limiting its operation ability.In this paper,the loss,temperature and ventilation of the SC in steady and transient process are studied,which provides a theoretical basis for improving the operating ability of the SC under system fault.The main work is as follows:1)The field-circuit coupled time-stepping finite element model,the stator and rotor loss model and the two-dimensional temperature field model of the SC are established.The stator and rotor loss and temperature distribution of the SC under steady-state are studied,and the accuracy of the method is verified.2)The stator and rotor loss of the SC are studied under different types of short-circuit faults in transmission line.The temperature rise of the rotor are calculated by using the loss as the heat source,and the relationship between the duration of the SC and the short-circuit type is obtained.The loss and temperature rise of the SC under different initial loads and different rotor slot wedge materials after the single-phase short-circuit fault of the system are studied,and the relationship between the transient operation ability of the SC and the initial loads and the slot wedge conductivity is revealed.3)The fluid field and temperature field model of the stator and rotor of the SC are established,and the fluid and temperature distribution of the stator and rotor under steady-state are obtained.The influence of the rotor hot air on the stator temperature calculation is studied,and the variation law of the temperature under different air intake is obtained.The loss and temperature rise of the stator and rotor of the SC are calculated under the over-excitation fault.Considering the influence of the rotor hot air on the stator transient temperature rise,the duration of the SC under different over-excitation degree is obtained.