Overhead Catenary Cables to Charge Electric Lorries.

And do not make the vehicle class 1 !


Taking the  commutating pantograph and DC bus idea further, and making those pairs of diodes totem poles of high power FETs, you can then also push power back into the line or take it out, as suits for example during braking.


Now we have a HVDC reserve, either side of which is at our overhead line voltage depending on instantaneous phase of each cycle.


We could play a trick, and supply power to the overhead lines in a similar way - i.e. excite each one with an AC plus a DC such that the most negative part of the cycle is near ground - then the negative side of our DC bus, will always be at or near that potential.


So if we wanted  to use railway like voltages, do 25KV FETs that can switch hundreds of amps exist? - well not as discrete components, yet, the upper bound is a few KV, and you need a factor of 2 or 3 for transients, but techniques do exist for stacking such devices. to make high voltage modules examples . 

The next step in any real design then next act is to transform down to a voltage and current more suited to batteries and traction motors, probably the low to mid hundreds of volts . It is the leakage of that transformer from HV to LV through inter-winding capacitance that would need great thought in the choice of switching frequency and core and insulation construction. None of it is impossible with existing parts, but it is certainly in the realms of  bosky powertronics, and not without risks.

And do not make the vehicle class 1 !


Taking the  commutating pantograph and DC bus idea further, and making those pairs of diodes totem poles of high power FETs, you can then also push power back into the line or take it out, as suits for example during braking.


Now we have a HVDC reserve, either side of which is at our overhead line voltage depending on instantaneous phase of each cycle.


We could play a trick, and supply power to the overhead lines in a similar way - i.e. excite each one with an AC plus a DC such that the most negative part of the cycle is near ground - then the negative side of our DC bus, will always be at or near that potential.


So if we wanted  to use railway like voltages, do 25KV FETs that can switch hundreds of amps exist? - well not as discrete components, yet, the upper bound is a few KV, and you need a factor of 2 or 3 for transients, but techniques do exist for stacking such devices. to make high voltage modules examples . 

The next step in any real design then next act is to transform down to a voltage and current more suited to batteries and traction motors, probably the low to mid hundreds of volts . It is the leakage of that transformer from HV to LV through inter-winding capacitance that would need great thought in the choice of switching frequency and core and insulation construction. None of it is impossible with existing parts, but it is certainly in the realms of  bosky powertronics, and not without risks.