Oct. 14, 1994

Toyota Develops "Hybrid" Electric Bus

Possible New Power Source for Urban Transport

Tokyo―TOYOTA MOTOR CORPORATION announced today that it has developed a new "hybrid" electric bus called the Coaster Hybrid EV, which is equipped with both a gasoline engine and an electric motor. The company considers the "hybrid" power system a possible new power source for urban-transport applications.

The vehicle's newly-developed "hybrid" power system utilizes a gasoline engine to generate electricity. The electricity is then used to propel the bus by powering the vehicle's electric motor, while also charging its batteries. In addition to being quieter and cleaner-running than the Coaster Diesel on which it is based, the Hybrid EV can cover long distances and does not have the distance-per-charge limitations typical of "pure" electric-powered vehicles.

The Hybrid EV's operating characteristics―clean emissions, low noise, and excellent fuel economy―make it perfect for applications such as short-distance urban transport services, community-service buses, and for use in nature parks. After completing evaluation tests on the Coaster Hybrid EV, Toyota plans to assess its practicality on public roads.

Features of the Coaster Hybrid EV

Hybrid Power Source
The Coaster Hybrid EV's gasoline engine runs constantly at between l,000rpm and 3,000rpm to generate electricity. During stops and constant-speed driving―when power consumption is minimal―excess power is used to charge the vehicle's batteries. During start-ups, acceleration, and high-speed driving―when power consumption is high―sufficient power is secured by drawing on the power stored in the batteries. This scheme enables the Hybrid EV's electric motor to deliver a maximum output of 70kw (95PS) with a small-displacement (1300cc) engine to achieve the running characteristics typical of a heavy, small-sized bus.
Clean Emissions
Emissions are kept to a minimum by running the gasoline engine at a constant speed, even during acceleration and high-speed driving. The engine is equipped with a three-way catalytic converter which reduces NOx emissions to one-tenth of those emitted by the Coaster Diesel model.
Low Noise
The Hybrid EV is as quiet as any pure electric vehicle, as its power plant is an electric motor, and because its gasoline engine runs at a constant speed and is small relative to the vehicle's size.
Excellent Fuel Economy
The Hybrid EV offers fuel economy roughly equivalent to that of its base vehicle, the Coaster Diesel, which itself features exceptional fuel economy. The Hybrid EV's superior fuel economy and range are achieved by running the gasoline engine within the most fuel-efficient speed range, and by using the electric motor as an energy source through its application as a generator during deceleration.

Reference