Patent Application
20050206331
The present invention relates generally to a hybrid locomotive power source and drive train configuration which is suitable a variety of applications.
A hybrid locomotive combines a prime power unit, an energy storage system, optionally a regenerative braking system, and an axle drive system. The present inventor has disclosed the use of a battery-dominant hybrid diesel-electric locomotive in U.S. Pat. No. 6,308,639 which is incorporated herein by reference.
In North America, railroad locomotives are typically diesel-electric locomotives in which a diesel engine drives an alternator/rectifier to produce DC electric power. This power is routed via an electric transmission to electric traction motors mounted on each driving axle of a truck assembly. Such diesel-electric locomotives may be configured to provide power to either AC or DC traction motors.
In another configuration, diesel-hydraulic locomotives are often used as shunting locomotives or as road locomotives in Europe. In these locomotives, the shaft output power of a diesel engine is coupled mechanically to a hydraulic variable gear ratio transmission (also known as a hydrodynamic or turbo transmission) which, in turn, drives all the propelling axles on the locomotive typically utilizing a system of gears, drive shafts and couplings.
Thus, there remains a need for a hybrid diesel-electric locomotive power system that can be adapted to a transmission and drive system such as used on diesel-hydraulic locomotives.
These and other needs are addressed by the present invention which is directed generally to a hybrid locomotive having a hybrid power system operably engaged with a motor. The motor operates a transmission or mechanical gearbox and any one of a number of known axle drive systems to achieve a locomotive configuration with a number of unique advantages.
In one embodiment of the present invention, a hybrid power system is used to provide AC power to a single AC motor and gearbox assembly. The gearbox assembly is connected to drive axles on the locomotive using any one of a number of known axle drive systems. Power for the AC motor is supplied by means of an inverter connected to a DC power bus. The DC bus receives input power from either or both of an energy storage system and a prime power source whose mechanical power output is converted to electrical power by an alternator/rectifier apparatus.
In another embodiment of the present invention, a hybrid power system is used to provide DC power to a single DC motor and gearbox assembly. The gearbox assembly is connected to the drive axles on the locomotive using any one of a number of known axle drive systems. Power for the DC traction motor is supplied by means of a chopper circuit connected to a DC bus. The DC bus receives input power from either or both of an energy storage system and a prime power source whose mechanical power output is converted to electrical power by an alternator/rectifier apparatus.
In another aspect of the invention, the DC electrical energy from the alternator/rectifier apparatus may also drive one or more additional inverters to supply the auxiliary power requirements of the locomotive and any attached cars.
In another aspect of the invention, a dynamic braking system may be employed to augment the main braking system. In addition, the dynamic braking system may include a regenerative braking system to recover kinetic energy dissipated during braking and return it to the energy storage system.
In yet another embodiment, the prime energy source of a hybrid locomotive may be augmented from time to time by an external source such as an overhead electrical catenary or a third electrified rail.
The above invention can provide a number of unique advantages over the prior art. The invention can allow a hybrid power supply to be used with axle driving systems typical of conventional diesel-hydraulic locomotives. This allows the locomotive to run on batteries alone when necessary for emission free operation. The invention can also allow the locomotive to run with minimal engine usage when necessary for low emissions operation. The invention can allow the locomotive to be capable of high accelerations when necessary by providing propulsive power simultaneously from both the prime power source and energy storage unit. The invention can allow the locomotive to capture kinetic energy from braking by a regenerative braking system connected to the energy storage system. The invention can also permit a wide range of combinations of prime power and energy storage which make the invention suitable for switcher locomotives, commuter locomotives, various industrial locomotives and as B-unit locomotives in locomotive consists.
These and other advantages will be apparent from the disclosure of the invention(s) contained herein.
As used herein, “at least one . . . and”, “at least one . . . or”, “one or more of . . . and”, “one or more of . . . or”, and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C”, “at least one of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, and A, B and C together.
The above-described embodiments and configurations are neither complete nor exhaustive. As will be appreciated, other embodiments of the invention are possible utilizing, alone or in combination, one or more of the features set forth above or described in detail below.
The engines 102 are large enough to provide a significant portion of the output power of the locomotive and therefore requires a fuel tank (not shown). The fuel tank can be located inside the locomotive or carried underneath as a belly tank or can be both. The power rating of the engines 102 is preferably in the range of 100 to 2,500 kW. The storage capacity of the energy storage unit 106 is preferably in the range of 500 to 2,500 kW-hrs.
The output shaft of the motor 104 is mechanically connected to a transmission or gear box 105. The gear box 105 may be reducing or increasing gears and may be single- or double-reducing or increasing gears. The gear mechanisms may be provided by helical gears and pinions, gear belts, chain and sprocket arrangements or any number of other well known gear box mechanisms. The gear box 105 rotates a drive shaft 107 which dives the axles and wheels 108. The axle drive mechanism can be any one of a number of known axle drive systems such as for example drive systems comprised of drive shafts, cardan shafts, universal joints, bevel gears, spur bevel gears, spur gears and the like. Examples of other drive systems include drive shafts and limited slip or self-locking differential systems. The locomotive configuration may be controlled from an operator's cab 101 or it may be a remotely controlled locomotive.
A number of variations and modifications of the invention can be used. As will be appreciated, it would be possible to provide for some features of the invention without providing others. For example in one alternative embodiment, the various inventive features are applied to vehicles other than locomotives, such as cars, railroad cars, and trucks. The control logic set forth above may be implemented as a logic circuit, software, or as a combination of the two.
The present invention, in various embodiments, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, sub-combinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments hereof, including in the absence of such items as may have been used in previous devices or processes, for example for improving performance, achieving ease and\or reducing cost of implementation.
The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention.
Moreover, though the description of the invention has included description of one or more embodiments and certain variations and modifications, other variations and modifications are within the scope of the invention, e.g. as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter.
The present application claims the benefits, under 35 U.S.C. § 119(e), of U.S. Provisional Application Ser. No. 60/551,519, filed Mar. 8, 2004, entitled “HYBRID LOCOMOTIVE CONFIGURATION”, which is incorporated herein by this reference.
| Number | Date | Country | |
|---|---|---|---|
| 60551519 | Mar 2004 | US |
