Primary wiring diagram of power system

The picture on the left shows the trolley bus voltage transformer. The neutral point of the star winding on the primary and secondary sides is directly grounded, and there is an open triangular secondary winding. The lightning arrester or overvoltage protector is connected in parallel in front of the high voltage fuse. The picture on the right shows the outgoing switch of a transmission line, which is a trolley circuit breaker. Current transformers are installed in phase A and phase C on the outlet side, and each current transformer has two groups of secondary windings. Field display and lightning arrester are installed on the outlet side, and the triangle below represents the cable outlet.