| High-voltage commutation equipments are more and more popular in the industrial production. The voltage class and the current class of the thyristor which are their key switch device are higher and higher, having been above 10KV/10KA, with the higher demand in practice. The technology of light triggered thyristor (LTT) is more and more mature at abroad; according to the prospect of the thyristor development at home, this paper designs the light triggered self-powered drive board, which combines the self-powered technology with the light triggered technology. It is used as the alternative technology of LTT, which is the application model of the light triggered thyristor in practice when it is combined with the thyristor.In practice, the typical application of LTT is the current source inverter and high-voltage direct current transmission (HVDC) system. With the implement of national energy saving engineering, the application of the high-voltage inverter is wider and wider, which is the key chain in the industry energy saving. It is difficult to study HVDC system whose technology is complicated and requirement is higher. The alternative technology of LTT is only used as one of the redundancy techniques for HVDC system. In this paper, this redundancy technique based on the current source inverter is introduced in detail.Current source inverter uses several SCR in series so that the system has more large capacity. With the system capacity larger and larger, the requirements for the high-voltage switch device are higher and higher. When one SCR doesn't conduct in series which should conduct, it is possible to be breakdown because of overvoltage that the voltage on series ones is on it. Indeed, the series SCR may be breakdown later on. For improving the system reliability, it's necessary to add the backup trigger-circuit to the SCR drive system. Just saying this, the paper brings forward a proposal that add self-powered drive system (SPDS) to SCR drive system. SPDS uses the energy storing in the RC snubber circuit as its own energy source, obviously improving system reliability. Foreign engineers and researchers have put SPDS in practice based on their intensive study. At home, there are no intensive researches on it by far. In this paper, its purpose is to develop SPDS for the current source high-voltage inverter; supplying a civil gap and providing some references for develop of other device's SPDS.SPDS for High-voltage SCR in high-voltage side is an important component of protector in the high-voltage inverter. It is the key unit to implement the backup trigger function. Firstly, this paper introduces the requirements of series-SCR and the work progress of RC snubber. Based on these introductions, the paper brings forward the principle and the realization of SPDS, introducing the function of every component. The key of SPDS design is the design and election of the self-powered circuit and the trigger type. Compared with other elections, the self-powered circuit based on RC snubber and the trigger type based on optic fiber are used in the design.Based on Multisim10, the paper introduces the simulation of self-powered circuit in detail, which is the key of the SPDS. It discusses the factors which are possible to affect the work status of SPDS by building the simulation models of single phase and three phases inverter based on the SCR. At the same time, it also makes analysis on some special conditions by modifying the parameter of the simulation circuit. The results of the simulations prove that SPDS is feasible which achieves the goal of the design.In the paper, it builds low-voltage experimental platform based on three phase inverter with SPDS which is used to observe the performance of the design in practice, which sets a good stage for the design in high-voltage practice.At the end of the paper, it prospects for the development direction of the self-powered drive system. |
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