Summary - K Suppl. 33 (06/2026) - ITU-T K.11 – Supplement on the protection of information and communication technology equipment with DC power supply against temporary overvoltage (TOV) in telecommunication centres

There is a certain severe overvoltage and overcurrent strike called temporary overvoltage (TOV) from the power supply side that impacts the normal operation of information and communication technology (ICT). This is caused by a fault in the public main power grid. Furthermore, the TOV can also transfer to the DC power supply of ICT equipment through the grounding point of the AC/DC rectifier in a telecommunication centre. To mitigate or reduce the loss and damage caused by TOV strikes, there are some research results and technical suggestions specified as follows:
1)For TOV on the DC power side, the paper analyses the generation source, transfer path, loss mechanism, TOV stress model and protection scheme etc.
2)In accordance with research on theoretical analysis, simulation, testing and verification etc, there are some test methods and solutions proposed.
Supplement 33 to ITU-T K-series describes the knowledge of temporary overvoltage of the DC power supply of telecommunication equipment in a telecommunication centre. It mainly includes the source of temporary overvoltage of the DC power supply of DC telecommunication equipment, the path of temporary overvoltage to the DC power supply, the damage mechanism of DC telecommunication equipment caused by temporary overvoltage, the simulation test method and protection from temporary overvoltage.