From Green Car Congress:
Electric motor and power electronics package for the be bop Z.E. Click to enlarge |
Renault will make its Renault Kangoo be bop Z.E. prototype electric vehicle (earlier post) available for test drives. The technology seen on this car is very similar to that which will feature on the brand’s upcoming production vehicles currently under development, and due to go on sale in 2011.
The Renault Kangoo be bop Z.E. prototype is powered by a 44kW (60hp) electric motor and is equipped with a 15 kWh Li-ion battery pack. With 18 months remaining before the release of Renault’s forthcoming production electric vehicles, Kangoo be bop Z.E. provides a range of approximately 100 km (62 miles). By the time of their launch, Renault’s electric vehicles will have benefited from an evolution to their battery technology which will take their real-world range to 160 km (100 miles), according to the company.
Electric Powertrain. The car is powered by a 44kW (60hp) electric motor which boasts energy efficiency of 90%. This motor revs to 12,000 rpm and immediately delivers peak torque, which is a constant 190 N·m (140 lb-ft). Acceleration and pull-away from low speeds are particularly responsive.
Renault Kangoo be bop Z.E.’s electric motor is coupled to a reducer which replaces the gearbox traditionally mated to internal combustion engines. This reducer has a single output ratio and ensures linear, stepless acceleration.
Electrical energy is transmitted to the motor via a power electronics unit which incorporates a controller. This transforms the 400V direct current into three-phase alternating current to power the motor’s rotor and stator. It also regulates the power and torque of the electric motor.
Situated near the controller, the converter converts the 400V DC stored in the traction battery into 12V DC to feed Renault Kangoo be bop Z.E.’s conventional onboard electrics and auxiliary functions (interior and exterior lighting, audio system, electric windows, etc.).
The junction box distributes the power current to the motor functions (battery, climate control and heating systems). This junction box also includes the charger which converts the 220V AC into 400V DC for battery charging purposes.
The 15 kWh lithium-ion battery pack from AESC (Automotive Electric Supply Corporation, a Nissan-NEC joint venture founded in April 2007), comprises 48 power modules, each of which incorporates four elementary cells. The modules are positioned in two rows, side by side. The four cells of each module store 8.4V, making a combined total of 400V for the 48 modules which make up the battery.
The AESC battery is maintenance-free and is expected to deliver between 80 and 100% of its original capacity for an average duration of six years. It will also be possible to charge it for short cycles with no adverse effect on capacity.
The compact dimensions of lithium-ion batteries enable the vehicle’s architecture to be optimized. In the case of Kangoo be bop Z.E., the 250 kg (551 pounds) battery is housed underneath the floor, between the front and rear seats. Its fitment required several modifications to the structure compared with the standard Kangoo be bop:
- The central section of Kangoo be bop’s floor was modified to house the battery without having to modify the wheelbase.
- To accommodate the battery, the floor is 45mm higher. As a consequence, the front seat rails are located directly beneath the seats in order to maintain the same cushion height. In addition, the car’ s ride-height has been lowered by 20mm to ensure the same access for rear passengers.
The battery of the production electric Kangoo Express will be located underneath the trunk floor, without affecting cargo space. The battery is cooled by ambient air flow due to the heat dissipation properties of its aluminium casing.
The Renault-Nissan Alliance is actively working on establishing recycling processes and infrastructures suited to automotive batteries. To put the demand for lithium supplies into perspective, the Alliance’s 250kg AESC batteries contain 3 kg of lithium. According to the mining companies Chemetall and SQM, lithium reserves are currently estimated to be between 14 and 17 million tonnes.
Charging methods. Renault Kangoo be bop Z.E. is charged via a socket located behind a flap at the front of the vehicle alongside the right-hand headlamp. Renault Kangoo be bop Z.E. permits two different battery-charging methods:
A conventional charge via a household mains supply (10A or 16A 220V) which can charge the vehicle in between six and eight hours. This method is suited to vehicles which are parked up overnight or during the day at the workplace.
A faster charge using a 32A 400V three-phase socket (infrastructure in the process of being developed) enables 80% of Renault Kangoo be bop Z.E.’s battery to be charged in approximately 30 minutes.
Kangoo be bop Z.E. is not equipped for rapid battery exchange, although this facility will be available on the other vehicles of the future range.
Renault Kangoo be bop Z.E. is equipped with a Marechal-type socket which will not feature on the production electric Kangoo Express. Twenty or so car manufacturers—including Renault&madsh;and energy groups are currently working with the German group RWE with a view to developing a standard plug.
This universal standard plug was shown in Hannover last April and will be employed to charge Renault’s forthcoming electric vehicles. This three-phase plug can be used with a 400V supply and, by the time these vehicles come to market, will enable a complete battery charge in approximately 20 minutes. This multi-partner agreement marks a significant step forward regarding the development of mass-market electric vehicles.
Range optimization. In addition to the information provided by the exterior gauges, Renault has developed a specific MMI (Man Machine Interface) to keep the driver informed about the vehicle’s current state of charge and remaining range:
A gauge alongside the speedometer displays the battery’s level of charge;
An “econo-meter” uses a new a new color-coded system to tell the driver how economical his or her driving is in terms of energy consumption (light blue for “normal” vehicle use, dark blue for “optimal” driving and red for excessive energy consumption likely to reduce the vehicle’s range).
The trip computer is adapted to the needs of electric vehicles and indicates the number of kWh remaining, average and instantaneous energy consumption and remaining range (in kilometers).
EDF and Renault recently signed an agreement concerning a battery charging system known as Power Line Communication (PLC) which permits communication between charge terminals and electric vehicles. This EDF-developed technique enables the safe exchange of data between the charge terminal and the vehicle with a view to transferring invoicing details and the location of the nearest station as a function of the vehicle’s remaining range. Renault will carry out integration tests with this system onboard in its upcoming vehicles.
Renault suggests that trying to accelerate as gently as possible with a view to minimizing energy consumption can be fun.
Well-to-wheel emissions, using a Mégane sedan as the baseline. Click to enlarge. |
The Alliance’s EV Strategy. The Renault-Nissan Alliance intends to mass market zero-emission vehicles. This commitment is founded on the underlying principle that electric vehicles—unlike internal combustion engines and hybrids—are zero-emission vehicles during their use on the road. Depending on how the electricity they use is produced in the different countries where they are driven, their well-to-wheel greenhouse gas emissions (equivalent carbon dioxide) can vary significantly. That said, electric vehicles generally tend to emit less greenhouse gases than equivalent internal combustion-engined vehicles.
The Alliance is actively forging associations with governments, city authorities and energy companies with a view to promoting the widespread use of electric vehicles across the world. The Alliance has already signed 26 such partnerships (up to the end of May 2009).
In May 2009, 10 years after the establishment of the Alliance, Renault and Nissan announced that their cooperation is to be stepped up. A small, bespoke team has been introduced with the mission to speed up and extend the synergies that are expected to enhance the performance of the two companies, and more particularly in the field of electric vehicles.
The electric vehicles produced by Renault and Nissan, for example, will be equipped with jointly-developed batteries. The Alliance is pooling its expertise with a view to achieving synergies at all levels and to enable key electric assemblies, such as the drive train, to be shared. Renault and Nissan are also merging their purchasing activities and pursuing the standardization of components in order to obtain the economies of scale required to permit the development of mass-market electric vehicles.
Although Renault and Nissan are seeking to share components, they are developing distinct line-ups of electric vehicles, with each line-up to be marketed and distributed separately.
Renault’s EV product plan. Click to enlarge. |
Renault’s product plan. In 2011, Renault will begin by introducing two electric derivatives of vehicles which have until now been powered by an internal combustion engine. The first will be a family saloon and will go on sale in Israel and in Europe. The second, also scheduled for release in 2011, will be an electric version of Renault Kangoo Express which will above all target professionals and fleet operators.
The electric vehicle line-up will then expand into other segments, with two new cars featuring specific, particularly innovative styling and architecture engineered to house an electric motor. This vehicle, too, is planned to be introduced in 2011, while a fourth model is due to come to market at the beginning of 2012.
Renault’s first electric concept car was Z.E. Concept which was shown at the 2008 Paris Motor Show. The next step in the programme was the release of a demonstrator vehicle—Renault Kangoo be bop Z.E.—for test-drive purposes. With 18 months remaining before the launch of the first commercially available models, this demonstration car features technology currently under development. Kangoo be bop Z.E. does not preview the production electric Kangoo Express; its aim is to enable drivers to get a feel for the sensation of driving an electric vehicle and to familiarize themselves with the new technology.
In 2010, Renault will bring out prototypes of the forthcoming electric Renault Kangoo Express for road-test purposes and to show how the project has progressed, as well as continuing to introduce Renault customers to this new form of zero-emission mobility. The first production electric Renault Kangoo Express will be available in the Renault sales network by the middle of 2011.
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