Is it legal for the developer to hand over the substation that has not passed the acceptance of the Electric Power Bureau to the owners' committee?

Substations are installed, managed and maintained by the Electric Power Bureau according to regulations. They will certainly not take over the substation that has not been accepted, so it is unrealistic for your property to do it by itself. The key is that commercial streets and comprehensive shopping malls are big consumers of electricity, and the maintenance cost for one year is definitely not low. It's best to find the local neighborhood Committee and the electric power bureau to sit down and negotiate.