Energy regeneration brake
The energy regeneration brake was the trade name for a system designed to automatically switch an electric motor into a generator as a vehicle slowed. Braking energy is absorbed so that batteries can be recharged, thus increasing the range of the automobile. The experimental Amitron, designed by American Motors, was the first car that used this regenerative braking technology, which has now become standard on all electric vehicles (EVs) and hybrids.
The "energy regeneration brake" system was developed in 1967 by American Motors Corporation (AMC) in cooperation with Gulton Industries (acquired by Mark IV Industries in 1986) for an experimental battery powered city car. This concept car was called Amitron, a completely battery powered urban vehicle, and its later iteration, the Electron. To achieve longer battery life between charges, the Amitron would have a "regenerative braking system" to generate battery-charging power as the car is slowed. Equipped with dual-type storage and propulsion batteries, the system was designed to be recharged while the car is cruising. The development of various methods to improve performance and range of the electric car also included significant progress for a "solid-state electronic CPU to efficiently use power and on-the-road regeneration". Research and development costs were to be split between the two companies, but at the time both AMC and Gulton were still a long way from commercialization.
This was the first use of regenerative braking technology in the U.S. However, the first vehicles to use this technology was the French Krieger Electric Carriage, a conversion of a horse-cab, with a separate electric motor in each front wheel with provision for charging the battery while descending a hill.
The AMC-Gulton automobile was capable of "nondissipative speed control" by capturing the kinetic energy that the car loses when braking; thus, energy is not wasted in heating up the brake linings. The car used a starter/generator compound motor that incorporated both series and shunt field windings. Early applications, such as on the Baker Electric Runabout and the Owen Magnetic, used many switches and modes controlled by an expensive "black box" or "drum switch" as part of their electrical system. The Amitron's electronic control of speed and regeneration was designed for efficiency and ease of use, while the "energy regeneration brake" also results in fuel savings. The concept car used batteries with a high "power-to-energy ratio" and they were also capable of repeated charging and discharging cycles.
The AMC partnership with Gulton evolved after the U.S. Congress passed three bills known as the Electric Vehicle Development Act of 1966. The legislation provided funding for electric car research in response to the rapidly decreasing air quality caused by automobile emissions. The two firms were developing new battery based on lithium with electronics and an advanced speed controller designed by Victor Wouk. However, a nickel-cadmium battery was used for their experimental 1969 plug-in electric vehicle (PEV) Rambler American station wagon. The heavy all-electric car had good acceleration, but a limited driving range.
The Amitron concept car did not get beyond the prototype stage. The expensive batteries and other factors contributed to the decision of AMC to suspend testing of this vehicle. This was along with the disappearance of other electric cars as the oil pipelines began flowing again. However, the energy regeneration from braking idea was later commercialized by the Japanese, and both Ford and Chevrolet licensed it from Toyota for use in their domestic-built hybrid vehicles. In summary, the "energy regeneration brake" developed by AMC was the first automobile application of solid state electronic and maintenance-free technology to capture energy from momentum.
Name for electronic control
During the late 2000s, a system described as "brake energy regeneration" was a misnomer for an electronic control unit used by BMW that engages the alternator during braking, while freewheeling during acceleration and limiting its horsepower draw from the car’s engine while cruising.
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