Thyristor Voltage Equalizing Network for Crowbar Application

التفاصيل البيبلوغرافية
العنوان: Thyristor Voltage Equalizing Network for Crowbar Application
المؤلفون: G., Subhash Joshi T., John, Vinod
سنة النشر: 2018
مصطلحات موضوعية: Electrical Engineering and Systems Science - Signal Processing
الوصف: Many high voltage applications are realized with series connected thyristors. Voltage imbalance among series connected thyristors during steady state as well as in transients is one of the major concerns. This voltage imbalance is mitigated by using static and dynamic balancing network. Dynamic balancing networks are typically designed based on reverse recovery charge of the thyristor during turn-off, which suits many applications. But this is not the case for a crowbar application, where turn-off of the thyristor is not a major circuit constraint. This paper proposes the design method for dynamic balancing network considering gate turn-on delay time and the balancing network component tolerances. The paper derives two models for the dynamic balancing network based on its charge-discharge cycle. The importance of charge-discharge cycle in the design of dynamic balancing network during high di/dt operation is emphasized. Influence of dynamic balancing resistance and crowbar current limiting inductance on voltage imbalance, charging current and discharging current is studied using the analytical model. The proposed design method also offers flexibility to incorporate differences in propagation delays among the thyristor drivers that are used to trigger individual thyristors. Such delays cannot be directly incorporated in the conventional balancing network design method based on reverse recovery. Further, it is also analytically shown that designing the dynamic balancing network based on reverse recovery charge makes the balancing network lossy and bulky for crowbar application. Simulation studies and experimental results on a 12kV , 1kA crowbar consisting of six series connected thyristors confirms the theoretical analysis and validates the proposed approach for crowbar applications.
Comment: This paper is a preprint of a paper accepted by IET Power Electronics and is subject to Institution of Engineering and Technology Copyright. When the final version is published, the copy of record will be available at IET Digital Library"
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/1802.06929
رقم الأكسشن: edsarx.1802.06929
قاعدة البيانات: arXiv