Australian suburban power distribution
The conductors at the top are a three-wire (delta), three-phase HV supply. In Australian suburbs, this is usually 11kV or 22kV. On Springvale Road in Glen Waverly, Melbourne, for example, it's 22kV. Where I live in outback Queensland, it's 11kV.

The object at the top of the pole is likely to be a sectionaliser - basically a switch with a few sensors and some crude logic. In the event of a fault, the sectionaliser will determine whether the fault is in front or behind of itself, and will lock out the faulty portion.



It could also be a simple fuse-holder, as Sparky256 suggests, though Australian utilities would normally use a simpler drop-out fuse holder, like the one shown below.



The conductors at the bottom are a four-wire (wye), three-phase + neutral LV supply. That would be 230/415 VAC, as you suggest.

The very bottom-most cable is usually telecommunications of some sort, i.e. phone lines.