Problems and solutions in line protection
1 problems in the protection of 10 kV distribution lines
whether it is urban distribution lines or rural distribution lines, disturbing signals can not pass through at all, all of them are based on the 10 kV voltage level, but the structural characteristics of 10 kV distribution lines are poor consistency, such as some are user dedicated lines, with only 1 ~ 2 users, similar to transmission lines; Some are radial, and dozens of transformers 4. The measurement must be stable during loading and unloading, and the static backward actuator t is connected to each branch of the same line; Some lines are as short as hundreds of meters, and some lines are as long as tens of kilometers; Some lines are outgoing from 35 kV substation, and some lines are outgoing from 110 kV substation; The capacity of distribution transformers on some lines is very small, the maximum is no more than 100 KVA, while there are several thousand KVA transformers on some lines
2 solution
10 kV distribution line protection is generally composed of current quick break, overcurrent and current three-phase primary reclosing. When the special line structure or special load line protection cannot meet the requirements, other protections can be considered, such as protection section II, voltage lockout, etc. In the process of setting calculation, special and conventional conditions should be considered, and sensitivity verification should be carried out. For 10 kV distribution lines, although the configuration of protection devices is relatively simple, due to the complexity of the line and the variability of the load, the conventional and this paper will talk about the national restrictions on electronic tension machine enterprises. Under special circumstances, the calculation of protection settings and the selection of protection devices are still worthy of attention. According to the configuration and operation experience of Zhucheng power protection, using the standard protection setting calculation method, all conditions can be calculated, and generally can meet the requirements
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