UQM Technologies Introduces High-Voltage DC-to-AC Inverters
15 October 2008
UQM Technologies has introduced two high voltage DC-to-AC inverters with continuous output ratings of 3 kW and 5 Kw. The high-efficiency inverters, which have an output efficiency of up to 93%, convert input voltages ranging from 250 to 450 volts into a nominal output voltage of 120 volts AC (60 hertz) at a continuous output current rating of 25 and 42 amperes, respectively.
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| UQM DC to AC inverter. Click to enlarge. |
The inverters are designed for use onboard electric, hybrid electric and fuel cell vehicles to convert high voltage DC power stored in vehicle batteries to high quality AC export power. The installation of an inverter on a vehicle permits the vehicle operator to plug-in a wide range of AC equipment such as power tools, welders, garden tools and various appliances in over-the-road truck sleeping compartments.
Each inverter is a compact 15 inches long, 9 inches wide and 4 inches tall and weighs 25 pounds. Additional product features include controller area network (CAN) control and diagnostics, digital signal processor (DSP) control, true sine-wave output, high inrush load capability, under-voltage protection and CISPR 25 Class 3 EMI compliance.
The expected roll-out of all-electric, hybrid-electric and plug-in hybrid-electric cars and trucks over the next several years is creating opportunities for additional auxiliary products that operate with the higher voltage electrical systems onboard these types of vehicles.
—William Rankin, UQM Technologies’ President and CEO.
It is good to have such units commercially available. The cost is very important. Some gasoline powered portable generators already have inverters of this quality built in.
All new subdivisions should have DC underground cables to supply two or more of these units at each house or apartment. The losses of AC underground transmission are quite high. UPS systems for each house could be implemented with a few diodes and a battery bank. The underground cables store enough energy that minor outages are eliminated. Flywheels could eliminate many of the rest. In larger buildings the power can be sent to each floor, appartment or tennant more efficiently as DC at the nearly 500 volts. A slighly higher voltage would allow their use from subway and light rail power systems. The Chunnel trains on the older tracks in England ran on these voltages until recently. ..HG..
Posted by: Henry Gibson | 15 October 2008 at 11:11 AM
Henry, do you have backing for the claim that underground AC cabling (of the length and type typical of utility wiring in subdivisions) is enough lossier than DC cabling to overcome the expense and losses of inverters?
Posted by: Engineer-Poet | 15 October 2008 at 08:20 PM
about time something like this was available!.. but a couple of caveats:
1. it stresses the battery in an EV to use this.. manufacturers will have to consider warranty issues when they offer it as an option.
2. it would be optimal to use it in a hybrid ev or just range extended ev that could start its generator/engine as needed to keep the battery charged. This has been done to Priuses already, with excellent results.
3. it will never be sold in the market to private people.. too much risk of getting electrocuted during installation by high DC voltages from EV battery packs, at least in the USA the risk of lawsuits would be high.. This is a shame!
4. I would like a 10-15kw inverter offered also, in places prone to hurricanes and power failures lasting weeks this inverter/car combo might be used to power a house.. AC, refrigerator and so on. A device like this would sell many many EVs... for a lot of people an EV is hard to economically justify but this would become disaster preparedness. You really dont want your sweaty wife screaming at you for weeks after a hurricane :)
5. A big market for agencies and construction companies that need portable power at the field.. no need to lug around a cumbersome generator or messy/dangerous refueling of same.
6. Such a device in combination with an EV with a range extender engine is probably a lot more fuel efficient than a comparable generator, and definetely a lot less noisy.
7. 93% efficiency is impressive.
Posted by: Herm | 16 October 2008 at 06:27 AM