Reasons for over voltage protection of thyristor rectifier circuit

In the thyristor rectifier circuit of communication input, DC output and components. All of them are protected by overvoltage protection such as RC absorption network or selenium pile, because SCR has poor ability to withstand overvoltage. While in the side and DC side communication often occurs some overvoltage, such as power grid operating overvoltage and lightning overvoltage, DC inductance load current changes induced overvoltage, fuses caused overvoltage and overvoltage when reversing thyristors, are likely to cause the decline of the damage of components or performance. So the overvoltage protection measures should be adopted.