High Voltage Solid State Switch Technology Research, A Number Of Thyristor Series

With the development of semiconductor industry, in many applications such as pulse power and variable power supply, application of solid-state switch instead of radio tube and traditional electromagnetic relay will be possible and the trend, and solid state switch will be used in more fields. The components which are suitable for working on switching state are MOSFET, IGBT and Thyristor (also called SCRs, short for Silicon Controlled Rectifiers). The former two are suitable for high frequency field and thyristor is suitable for low frequency field. The voltage of Single device is limited, and high voltage switch should be obtained by using some devices in series linked mode. Induced by the practical need of measuring system of ferroelectric hysteresis loop of ferroelectric material, driven by high voltage pulse isolation transformer, a 20KV solid state switch consisting of 28 inexpensive general thyristors arranged in series has been developed.The key technologies of build solid state switch by series link of thyristors are as follows: trigger circuit of the thyristors, design of the high voltage pulse isolation transformer, produce of the initial control signal, voltage balancing and over voltage protection of the thyristors component.Upon those technologies, the experiment circuits have been designed and the components have been selected, single-on experiment of the switch was done. The experiments results showed that by choosing the thyristors whose parameters are approximately the same, high voltage solid switch can be obtained by arranging many general thyristors in series. Which offered an design idea of making inexpensive high voltage solid state switch.The control signal of the circuit in this article was given by the signal generator. Using PC or programmable devices instead of the signal generator, a high voltage solid state switch controlled by programmes will come into true.