With recent renewed interest in the 2kW AC-DC Battery Charger and 300W, high input voltage DC-DC converter that we provided for the SRZero all-electric car (EV), we decided to revisit the story of this landmark 26,000 km journey.
The Racing Green Endurance (RGE) team of Imperial College (UK) successfully drove their SRZero, long-range all-electric car along the 26,000 km Pan American Highway – the longest highway in the world. The starting point was Prudhoe Bay in Alaska, the finishing line, Tierra Del Fuego in Argentina. Their ultimate objective was to demonstrate the range and endurance of EV (electric vehicle) technology. ABSOPULSE Electronics is proud to have been a part of this story.
ABSOPULSE Electronics BCH 2K-E/600-3U3, a rugged 2kW AC/DC battery charger and the HVI 300-600/14-F3, a high-input voltage DC/DC converter/charger were selected by the RGE team to play a key role in the on-board electronics of their all-electric ‘Super-Car’.
The SRZero is equipped with a 600V lithium-ion phosphate battery pack, with a total capacity of 56kWh. ABSOPULSE’s BCH 2K-E/600-3U3 battery chargers were designed to accept 240Vac (195-264Vac operating range) input, to charge the battery pack from 220/240V AC power sources en route. This high voltage charger delivers 2kW/600V/3.3A continuous for the output and for charging the 600V battery pack, with the output adjustable 520-630V via trimming potentiometers. An internal separaton diode allows for two BCH 2K-E/600-3U3s units to be connected in parallel. The charger measures 3U (187mm) x 132 x 407mm (7.4” x 5.2” x 16”).
The role of ABSOPULSE’s HVI 300-600/14-F3 high input voltage DC-DC converter in the SRZero, according to Alexander Schey, RGE Project Manager, is effectively the same as an alternator in an IC car, enabling the SRZero’s 600V lithium iron phosphate battery pack to float charge a 12V battery, which in turn powers the car’s low voltage control system. It was essential that the unit delivered 300W continuously and reliably, as the control system operated all safety features as well as lights, display, and other components. The generic data sheet for this design, the HVI 300-F3, provides further input/output options.
The HVI 300-600/14-F3 is equipped with non-destructive reverse polarity protection on the input, surge protection and high-grade input/output filtering; 3kVdc input to output isolation ensures that the control system is protected from high voltages from the 56kW battery pack. The unit is filtered to meet EN55022 Class A EMI conducted and radiated, an important consideration in electric vehicles where EMI can cause electrical systems to behave unreliably. Cooling is combined: by conduction to a base plate, and by convection. This compact unit measures 132 x 64 x 300 mm (5.2″ x 2.5″ x 11.8″).
Both ABSOPULSE units are conformal coated and heavily ruggedized to ensure immunity to shock, vibration, humidity, moisture and airborne contaminants – essential for harsh open-road conditions. Certain stretches of highway were extremely rough, with one 100 km stretch of gravel presenting the ultimate shock and vibration test.
According to Toby Schulz, ABSOPULSE’s chargers “worked magnificently in combination with the rest of [the] system and spelled no problems taking them into operation for the first time…. The components were in near continuous operation for 5 months. [they] performed very reliably over the course of the mission”.
To read more about the RGE adventure, and how the SRZero electric car and the RGE team withstood the rigours of extreme driving conditions, please visit their website at http://www.racinggreenendurance.com/