Professional accessories PFTL101B 5.0KN 3BSE004191R1

Professional accessories PFTL101B 5.0KN 3BSE004191R1

Professional accessories PFTL101B 5.0KN 3BSE004191R1

The different network configuration classes are:

1. Parallel line with common positive and zero sequence network 2. Parallel circuits with common positive but isolated zero sequence network 3. Parallel circuits with positive and zero sequence sources isolated. One example of class 3 networks could be the mutual coupling between a 400kV line and rail road overhead lines.

This type of mutual coupling is not so common although it exists and is not treated any further in this manual. For each type of network class, there are three different topologies; the parallel line can be in service, out of service, out of service and earthed in both ends. The reach of the distance protection zone 1 will be different depending on the operation condition of the parallel line. This can be handled by the use of different setting groups for handling the cases when the parallel line is in operation and out of service and earthed at both ends. The distance protection within the IED can compensate for the influence of a zero sequence mutual coupling on the measurement at single phase-to-earth faults in the following ways, by using:

• The possibility of different setting values that influence the earth-return compensation for different distance zones within the same group of setting parameters.

• Different groups of setting parameters for different operating conditions of a protected multi circuit line. Most multi circuit lines have two parallel operating circuits. Parallel line applications This type of networks are defined as those networks where the parallel transmission lines terminate at common nodes at both ends. The three most common operation modes are:

1. parallel line in service.

2. parallel line out of service and earthed.

3. parallel line out of service and not earthed.