Resarch Of Low Switching Energy Loss Based Repetitive Control Method For Reversely Switched Dynistor And Its Cascadable Modular Design

The requirement of application advanced the pulsed power technology to a new developmental stage.The pulsed generators are required to operate in continuous mode.The developments of the switching devices greatly affect the developments of the frequency pulsed generators.Currently,reversely switched dynistor(RSD)is the most promising alternative in semiconductor switches.RSD has characteristics of achieving several tens kV voltage,hundreds kA current,switching under microsecond or nanosecond and easily in series.There were no reports about repetitive pulsed generators based on RSDs.High energy loss in the triggering process and inflexible in different discharge situation are two of the major limiting factors.In this thesis,a low switching energy loss control method of RSD is provided which is more suitable for repetive pulsed generators.Compared with the traditional control method,the new control method can enhance the saturability of commutation.Firstly,the unique internal structure and commutation characteristics of RSD are analyzed in detail.In order to ensure the RSD complete conduction,sufficient pre-charge provided in triggering process is necessary.On this basis,the conventional triggering methods are described.Then,a new two-step triggering circuit based on RSDs is proposed.The triggering method can effectively reduce the power dissipation during the control action and make the RSDs more befitting as the pulse switch in the repetitive pulsed system.The parameters of the two-step triggering circuit are designed and optimized by establishing the RSD's reverse trigger simulation model.The second step of the new control method is the decisive function for reducing the switching energy loss in the triggering process and heating in continuous discharge mode.Furthermore,each part of the pulsed system is described and designed in detail.In order to ensure that the pulsed system's structure is compact and discharge action is flexible,the triggering circuit is designed in cascade.The magnetic switch that used as a co-application switch with RSD is designed.Finally,the emulational and experimental results show that the two-step control method is feasible.By comparing two-step triggering method with traditional control method,the results verify that two-step trigging method can reduced the switching voltage peak and dissipation.Finally,under the single discharge circumstances,we obtain the current pulse of rise rate of 1.2kA/?s with three model RSDs in series that withstand1800 V voltage.Under the repetition discharge circumstance,the frequency is 0.15 Hz,while the voltage is about 1800 V,the current rise rate is about 1.2kA/?s.