Research On Electromagnetic Characteristics Of High Impedance Controlled Shunt Reactor Of Transformer Type

High impedance controlled shunt reactors(CSRs)of transformer type are important reactive power compensation devices in extra high voltage(EHV)and ultra high voltage(UHV)power grids,and would be widely applied.This dissertation is supported by the National Natural Science Foundation of China(51277064)"Research on the basic theory and key techniques of UHV controllable shunt reactor".The research on electromagnetic characteristics of high impedance controlled shunt reactor of transformer type is carried out.The main contents are as follows:A transient electromagnetic model for controlled shunt reactor of thyristor controlled transformer(TCT)type based on duality theory is proposed and established.A 220V single-phase prototype for the CSR of TCT type is developed.The prototype experiment and transient electromagnetic model calculation are done.And the validation of the transient electromagnetic model is made.The transient electromagnetic characteristics of the single-phase CSR of TCT type are obtained.The transient electromagnetic model of the three-phase CSR of TCT type is established.The operation characteristics of the three-phase CSR of TCT type with star-connected thyristor valves are compared with that of the three-phase CSR of TCT type with delta-connected thyristor valves.An improved coupled electric circuit and magnetic circuit method for the dynamic leakage magnetic field calculation of the CSR of TCT type is proposed.The mathematical model of the CSR of TCT type is derived and established based on the improved coupled electric circuit and magnetic circuit method.When the CSR of TCT type is operating at the capacitive and inductive reactive power modes,the calculated results are compared with experimental results.And the validation of the improved coupled magnetic circuit and electric circuit method is made.The dynamic leakage magnetic field characteristics of the CSR of TCT type are obtained.The dynamic leakage magnetic field calculation of the CSR of TCT type is made based on the indirectly coupled field-circuit method.And the further verification of the improved coupled magnetic circuit and electric circuit method is made.A DC bias characteristics analysis model for the CSR of TCT type based on J-A model is proposed and established in the thyristor abnormal operation state.The effect of five parameters on hysteresis loop is analyzed based on J-A model.The prototype experiment is done and the validation of the model is made.The DC bias characteristics of the CSR of TCT type are analyzed in the conduction state of single thyristor and the non-symmetrical conduction state of thyristors.The effect of the firing angle,the input voltage and the filter on DC bias characteristics of the CSR is obtained in the conduction state of single thyristor.Dynamic electromagnetic characteristics of the small size stepped controlled shunt reactor(SCSR)are analyzed based on the improved coupled electric circuit and magnetic circuit method.And the experiment of the small size SCSR is made.The electromagnetic characteristics of the ultra high voltage SCSR are analyzed based on the finite element method and the transient electromagnetic model of the duality theory.The effect of the magnetic clamp on leakage magnetic field characteristics of ultra high voltage SCSR is analyzed.