Why can't the medium voltage distribution network run around the network?

Although the phase sequence of power supply in two substations may be the same, there may be a phase angle difference. Because their superior power supply and main transformer wiring group may be different. The voltages will not be exactly equal. How can you ring the net?

There are also power flow problems, line impedance and load distribution problems, and protection setting problems, which need to be calculated.

The operation of power system ring network is a very complicated subject, involving many aspects. Only after detailed calculation and sufficient argumentation can we decide.