Electric Bus Demonstration
New Flyer Battery-electric buses enter into service with Winnipeg Transit
Winnipeg Transit is now using up to four New Flyer Xcelsior® battery-electric transit buses in daily service as part of an electric bus demonstration. The project is a collaboration involving the City of Winnipeg, the Province of Manitoba, Manitoba Hydro, New Flyer Industries, Mitsubishi Heavy Industries, Red River College, and Sustainable Development Technology Canada.
The buses will be in daily operation on the route 20 Academy-Watt, a 40 kilometer, two-hour route starting at Winnipeg Richardson International Airport, making its way through the city centre to East Kildonan and returning to the airport. The route was chosen as its length, speeds and loads are typical of many central business district routes in Canada and USA. Winnipeg Airports Authority permitted New Flyer to install a high power charging station at the airport, a project that was completed in October of 2014.
Zero-emission battery-electric propulsion transit buses are expected to significantly reduce green house gas and smog-causing criteria air contaminant emissions. In Manitoba, where the electrical grid is highly renewable (nearly 100 percent of electricity is generated without burning fuel), the use of electric propulsion buses are expected to translate to an estimated reduction of 160 tonnes of green house gas emissions, per bus, per year.
How it works
The electric bus is powered by energy stored in rechargeable batteries rather than fossil fuels. Instead of an internal combustion engine, it’s propelled by an electric motor. The principle is similar to a series hybrid transit bus but rather than an engine powering an AC generator that supplies power to an AC electric drive motor, the batteries supply power to the motor. The batteries supply high voltage DC power that is inverted to 3 phase AC power with variable frequency control. The AC motor speed and therefore the speed of the bus is related to the frequency of the power supplied by the control system. The frequency is determined by the bus operator who uses the accelerator pedal to select the speed of the bus based on the required driving conditions.
Much of the braking force of the bus is also provided by the electric drive system. When the operator applies the brakes, the control system converts the electric drive motor into a generator that absorbs the kinetic energy of the moving bus to slow down the bus and transform that energy into power to recharge the batteries.
The lithium ion batteries store up to 200 kWh of electricity and is monitored by a sophisticated battery management system that ensures the batteries operate efficiently and that their lifespans are maximized.
How the bus charges
Buses will pull up to a specially constructed terminal at the airport that houses a rapid charging station. A roof mounted pantograph (similar to the technology used in city trams around the world) connects to the overhead charger interface. The pantograph is deployed automatically without the operator leaving the driver seat. Before charging begins, the system goes through a verification routine that ensures the bus is properly connected to the station and the charging process is fully automatic.
The charging station supplies up to 300 kW of power to the bus and has the capacity to recharge the bus in about 10 minutes after each round trip on the route. Charging will occur during the scheduled layover time at the airport terminal while the bus is waiting to start its next trip.
The bus will leave the airport for the outer terminal in East Kildonan through the downtown and will return to the airport approximately two hours later. The bus, which has the battery capacity to allow for operation of up to five hours between charges, is capable of maintaining service for more than 20 hours a day, seven days a week, when kept at full charge.
To learn more you can watch this Red River College (one of the project partners) video on the Zero Emissions Electric Transit Bus.