Patent Application
20210300327
This disclosure relates to a field of heavy truck hybrid power system and control method.
Hybrid vehicles are usually powered by a combination of a combustion engine and an electric powered motor. The electric motor is powered by a battery, and the electric motor may be coupled to a common drive axle of the vehicle. The common drive axle may be driven by power generated by both the electric motor and the combustion engine. When the hybrid vehicle is moved from rest position or accelerated from a lower speed to a higher speed, the drive axle of the hybrid vehicle may be powered by the electric motor, and at cruising speed or downhill, the drive axle may be powered by the combustion engine. Hybrid vehicles in this regard, enjoy a performance improvement during acceleration and a better gas mileage with lower carbon emission.
Heavy trucks or semi-trucks, which are classified as class 7 or class 8 commercial trucks are based on a gross vehicle weight rating (GVWR), are powered by combustion engines which are rated at more than 400 horse power without a reduction in engineH size for concerns of engine damages and poor drivability control.
The disclosure is better understood with reference to the following drawings and description. The elements in the figures are not necessarily to scale, emphasis are instead being placed upon illustrating the principles of the disclosure. Moreover, in the figures, like-referenced numerals may designate to corresponding parts throughout the different views.
In the following, only certain examples are briefly described. As those in the art would realize, the described examples may be modified in various different ways, all without departing from the spirit or scope of the present disclosure.
The non-electric powered medium truck engine 104 may be mounted near the forward end 101 of the heavy truck chassis 102, a drive axle 106 which is mounted near a rear end 103 of the heavy truck chassis 102, is coupled to the non-electric powered medium truck engine 104. An electric powered axle 108 is positioned closer to the rear end 103 of the heavy truck chassis 102 after the drive axle 106 as an added axle or a replaceable axle.
The non-electric powered medium truck engine 104 which is rated between 250 to 380 horse power may be one of a gasoline engine, a diesel engine, a propane engine, a natural gas engine, an ethanol engine, a biofuel engine, or a hydrogen engine.
The electric powered axle 108 is powered by current sourced by a rechargeable battery 110. A control system 120 having a processor 222 executes a program or an application 224 stored in a memory 226, controls when and how much current may be sourced to power the electric powered axle 108 to assist the non-electric powered medium truck engine 106 and to engage the drive axle 106 to recharge the rechargeable battery 110 during vehicle deceleration.
In an example, the rechargeable battery 110 may include a bank of batteries of a same type connected in parallel to increase current output. The types of rechargeable battery 110 may be at least anyone of: a Lithium Ion battery, a Molten Salt battery, a Nickel Metal Hydride battery, a Lithium Sulphur battery and a Lead-Acid battery, or any similar types with a high power density that can deliver high current throughput and can be rapidly recharge in a short time. The charge storage capacity of the rechargeable battery 110 may be rated at a minimum of at least 100 kWh. The recharging of the rechargeable battery 110 may be performed at home, at a dedicated electrical charging station or recharged locally while driving through an in-vehicle regenerative charging system such as through regenerative braking or from conversion of mechanical energy into electrical current for recharging.
In practice, an output torque under a 40% torque displacement may be set as an upper threshold. When the hybrid heavy truck 100 is at cruising speed operating in region 304 under the 40% torque displacement threshold, the hybrid heavy truck 100 may be sufficiently powered by only the non-electric powered medium truck engine 104 (e.g., internal combustion engine). However, when the heavy truck is moving from a rest position, starts climbing a hill or is passing another vehicle, the non-electric powered medium truck engine 104 needs to supply additional power to meet the power requirement by increasing torque in the underpowered non-electric powered medium truck engine 104. The powertrain sensor 204a may send out a signal to the control unit 120 to indicate that the engine torque has exceeded the upper torque threshold.
The control unit 120 may transmit a command through the communication bus 124 to enable the battery 110 to source an amount of current to drive the electric powered axle 108 to reduce the burden and the wearing of the non-electric powered medium truck engine 104 in region 306, by lowering the torque displacement percentage to sufficiently close to or below the 40% torque displacement threshold. In brief, the dynamics of coordination between the underpowered non-electric powered medium truck engine 104 and the electric powered axle 108 may be accomplished through power peaking detection or torque spiking detection over a defined time duration as shown in
In a case when the control unit 120 detects a zero torque displacement or a negative torque displacement during downhill or deceleration caused by braking, the control unit 120 may activate regenerative charging functions in the regenerative braking system 232 in the wheels to help slow down the hybrid heavy truck 100 and to recharge the battery 210. In a case when the battery 210 indicates that it is below a specified level in charge, the control unit 120 may force charge the battery through generating excess power from the non-electric powered medium truck engine 104.
In practice, the heavy truck 100 may be classified as a class 7 or a class 8 commercial truck based on gross vehicle weight rating and the non-electric powered medium truck engine 104 is rated to output less than 380 horse power. The non-electric powered medium truck engine 104 may be powered by a gasoline engine, a diesel engine, a propane engine, a natural gas engine, an ethanol engine, a biofuel engine, or a hydrogen engine. The rechargeable battery 110 may be a battery bank including one or a combination of: Lithium Ion battery, Molten Salt battery, Nickel Metal Hydride battery, Lithium Sulphur battery or a Lead-Acid battery. The rechargeable battery 110 has a minimum capacity rating of at least 100 kWh, which may be rechargeable through a charging station or an in-vehicle regenerative charging system.
The control system 200 may be coupled to a plurality of sensors which detect events that determine when to apply electric current to the electric power axle. The plurality of sensors include one or more powertrain sensor that monitors one or both of engine torque and revolutions per minute. The control system 200 may transmit a command that enables the battery 110 to source electric current to the electric powered axle 108 in response to an output from a throttle position sensor 204a or an output from a barometric pressure sensor. The control system 200 that transmits commands that enables the battery 110 to substantially reduce or completely cut off the electric current sourcing the electric powered axle 108 in response to a change in a load event. Such change in the load event may be detecting a spike of the torque for a defined time duration.
The cost reduction in installing a medium truck engine 104 into a heavy truck and the reduction in weight in using a medium truck engine more than offset the cost and the added weight and of the rechargeable battery 110. Furthermore, the use of a medium truck engine and the electric powered axle improves the fuel economy of the heavy truck and substantially reduce the carbon emissions of the heavy truck.
Other systems, methods, features and advantages will be, or will become, apparent to one with skill in the art upon examination of the figures and detailed description. It is intended that all methods, features included within this description, be protected by the following claims.
