I think you are off by 3 orders of magnitude unless you are planning on putting 1000 motors on each wing. I said 15000 kW. That's 15 MW. 300v @ 50A is only 15000 W or roughly 20 HP (actually a bit less when you consider the power factor).
They'll actually need some very high voltages to make this work. That's going to be an enormous challenge - even simple motor windings, what will you insulate them with?
15MW? That's some serious power, are you sure about that number?
If you watch agentjayz on YouTube he rebuilds turbojets that have been converted to become gas generators for power plants and some of those are easily capable of generating 30000 hp using tech from the 60s.
It really is phenomenal how much power turbine engines can make. There is a thread on the Concorde [2] that goes through a q&a session with the people who operated it. In that thread it says that the engines at idle consumed some 5 metric tons of fuel per hour per engine.
1: http://www.aerospaceweb.org/question/propulsion/q0195.shtml
2: http://www.pprune.org/tech-log/423988-concorde-question.html