transit bus recharging system

[ATBradbury]

Hello

I am researching rechargable buses and hybrids that could top up power at bus stops. Intended for UK city routes. I am needing to identify charging equipment as well as resources on related schemes.

The charging rate may be as high as 200kw and presumably will be a 750volt charging system.

Thanks and regards

 

[cranky108]

200kw/750v=267 amps that would take a healthy plug. How long would the bus stay at that location, and are you expecting the driver to plug/unplug, and take money?

Maybe a short over head rack might work better. Or make that two or more for a complete circuit (I assume rubber tires).

 

[ATBradbury]

hey thanks for reply

Yes thats the upper ammount and it assumes charging 3+kwh at the stop in a single minute. From driver surveys and other sources the bus type I am researching would basically be at the stop one minute+, and the good thing is that as the bus is bus is filled it needs more power but will get more charging time. It will also have about 2 minutes minimum at the end of the route which should help spread demand a bit at some stops with some reserve.

The charging rate is only possible with the performance claims of the most leading edge batteries, unless much larger battery packs are used, but its a starting point, otherwise more stops can have chargers and the rate reduced a lot. I intend to model for only 10 or so charging stops on a typical transit route of 20km round trip.

 

[ATBradbury]

yes also the charger would be overhead and I am exploring that option as well.

 

[ykee]

Charging needs to be done carefully, and as the battery approaches full charge it should be slowed down. Assuming you'd use sealed or AGM type batteries, overcharging can lead to heating & damage. I'd be very concerned about doing a rapid charge. Battery lifetime will be affected by the depth of discharge, the larger the discharge/recharge, the shorter the life.

Would you consider a means of swapping batteries instead and recharging the spares slowly? Maybe this requires more physical infrastrucutre.

 

[ATBradbury]

well yes for this system were hoping that a battery can be fast recharged in the bus and that a reasonable capacity can be cycled without damaging it. Were also hoping to utiliuse the efficiency of lithium ion type batteries to mitigate against overheating. I'm sure this sort of stuff is studied in defense sector but such organisations dont seem to want to talk to small fry.

 

[cranky108]

At first I thought about the large shore power plugs that the railroad uses, but having the driver plug that in at each station seemed like to much.

If I recall correctly, the fastest electric car used "D" cell batterys because of the power density, and discharge capacity.

If heating is a problem, then a passive cooling system is possible. Maybe an aluminun rack, with some sort of cooling fins.