A hybrid train is a locomotive, railcar or train that uses an onboard rechargeable energy storage system (RESS), placed between the power source (often a diesel engineprime mover) and the traction transmission system connected to the wheels. Since most diesel locomotives are diesel-electric, they have all the components of a series hybrid transmission except the storage battery, making this a relatively simple prospect.
Diesel electric locomotives may have most of what they need for regenerative braking since they might already use dynamic braking. This uses the traction motors as generators to convert much of the train's kinetic energy to electrical energy, but without a way to store the generated electricity it is simply converted to heat with large rooftop resistor banks and dumped to the atmosphere with the aid of cooling fans.
Using a storage system means that a non-fully electric train can use regenerative (as opposed to merely dynamic) braking, and even shut down the main power source whilst idling or stationary. Reducing energy consumption provides environmental benefits and economic savings.[1] A smaller scale version of the concept is found in hybrid automobiles, such as the Chevrolet Volt.
Development
The Patton Motor Car, manufactured by Patton Motor Company, was a petrol-electric hybrid system, although the term hybrid was not yet in use. William H. Patton filed for a patent on February 25, 1889; the drawings on his patent application resemble later descriptions of his first prototype.[2] Patton built a tram car that was in experimental service in Pullman, Illinois in 1891 and a small Patton locomotive was sold to a street railway company in Cedar Falls, Iowa in 1897. The latter used a 2-cylinder, 25 hp gasoline engine to drive a 220-volt generator that served to charge the 200-Ampere hour 100-cell lead acid battery in parallel with the traction motors. The engine ran at constant speed, with a shunt-wound generator that also served as an electric starter motor. A conventional series-parallel controller was used for the two 35 hp traction motors that drove the wheels of the locomotive.[3][4][5]
In 1986, Czechoslovak locomotive manufacturer ČKD built a prototype hybrid shunting locomotive termed the DA 600. The locomotive was powered a 190 kW diesel engine and four electric motors, with a maximum overall power 360 kW powered from batteries. The batteries were recharged while the diesel engine was running, by regenerative braking or from external electric power.[9]
After tests on the Railway test circuit Velim and some minor tweaks, the locomotive was lent to the Olomouc train depot and successfully operated there for ten years. Czechoslovakia failed to mass produce the locomotives, mainly because of a lack of battery manufacturing capacity.[10]
The design had two 65-kilowatt fuel cells and six hydrogen tanks under the floor, with a lithium-ion battery on the roof. The test train was capable of 100 kilometres per hour (60 mph) with a range of 50–100 kilometres (31–62 mi) between hydrogen refills. Research was underway into the use of regenerative braking to recharge the test train's batteries, intending to increase the range further. JR had stated that it hoped to introduce the train into scheduled local service during the summer of 2007.[11] Technology tested on this train was incorporated in the KiHa E200 diesel/battery railcars entering service in 2007.
The first JR Freight Class HD300 shunting locomotive was delivered from Toshiba on 30 March 2010.[12] The new locomotive uses lithium ion batteries, and is designed to reduce exhaust emissions by at least 30% to 40% and noise levels by at least 10 dB compared with existing Class DE10 diesel locomotives.[13][14]
During 2007, a modified Class 43 power car ran on the Great Central Railway and then as part of the Network Rail New Measurement Train (a 200-kilometre per hour track-recording train). The Hitachi developed system used a battery-assisted diesel-electric drive system; the hope being that it would demonstrate a cut in emissions by up to 50 percent and a reduction in fuel consumption costs of 20 percent.[16] The modified locomotive, named Hayabusa, was semi-permanently attached to a converted passenger carriage containing the battery bank during the testing period.
Since 2015, Vivarail has converted some former London Underground D78 Stock for rural services, branding them as D-Train. Some of these converted Class 230 units employ hybrid diesel-electric series propulsion.
In 2022, Chiltern introduced to revenue service a Class 168 whose diesel hydraulic transmission had been retrofitted with a diesel hybrid drive.[17]
North America
Railpower
A Green Goat hybrid shunting locomotive
In 2004, Railpower Technologies, a Canadian company, began running pilots in the United States with the Green Goat shunting locomotives. The trials led to orders by the Union Pacific and Canadian Pacific Railways, starting in early 2005. These diesel-electric hybrid trains are expected to cut emissions by up to 90 percent and to decrease fuel consumption by up to sixty percent, when compared to conventional diesel-powered locomotives. The "Green Goat" locomotives were intended to be used in marshalling yards.[18][19][20]
Progress Rail delivered two hybrid EMD GT38H locomotives to Brazil around October of 2023, making them the first two in Brazilian revenue freight service.[30]
^国内初のHV機関車 JR貨物が試作車を報道陣に公開 [JR Freight unveils prototype of Japan's first hybrid locomotive to media]. The Sankei Shimbun (in Japanese). Japan. 25 March 2010. Archived from the original on March 29, 2010. Retrieved 30 March 2010.