Patent Publication Number: US-2007095586-A1

Title: Power regeneration system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      This application claims priority to and the benefit of the filing date of U.S. Provisional Application No. 60/27,958, filed on Oct. 18, 2005, entitled “Regeneratively Charged Electric Vehicle,” which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION  
      This invention relates generally to power recharging systems, and more particularly, to regenerative power charging systems for electric vehicles (EVs).  
      EVs typically include one or more rechargeable power supplies, for example, battery packs, for storage of electric power. The stored electric power may be used to power a drive motor to propel the vehicle and several electronic elements used to control the vehicles performance and safety while being driven. For example, known EVs typically include a motor controller that not only provides the amperage required by the motor to move the vehicle (e.g., power from the battery pack to the motor), but also monitors the flow of that power and other aspects of motor performance, such as the ohms reading from a potentiometer. If a reading is out of a predetermined and/or preprogrammed value range, then for example, the logic portion of the motor controller shuts off the power portion of the motor controller, thereby turning off the power to the motor and bringing the vehicle to rest until the condition (e.g., performance abnormality) is corrected. Once the condition is corrected the motor controller resumes normal operating power functions, for example, according to the drivers input with a potentiometer that usually operates in conjunction with the foot feed, commonly referred to as the “gas pedal” of the vehicle.  
      Additionally, when “regenerative braking” is incorporated in an EV, either the motor acts as a regenerative source of power upon deceleration, which typically supplies less than twenty five percent of the used battery amperage back to the battery pack during deceleration once the brake pedal is applied, or an additional alternator or generator and regulator are incorporated in the system, supplying even less battery amperage back to the battery pack than the motor during regeneration and deceleration. With only twenty five percent regeneration of the amperage draw during brake application occurring during deceleration and deceleration occurring only a very small percentage of the time the vehicle is traveling, the amount of regeneration is even smaller resulting in a very small and inefficient recharge verses amperage draw ratio with the conventional EV. Thus, an EV has a substantially lower amount of available travel distance compared to a vehicle using an internal combustion engine and a supply of gasoline or diesel. For example, a typical gasoline powered automobile can travel three to four hundred miles on a tank of fuel and takes about five minutes to refuel. The average EV only travels about one hundred miles per battery charge and typically takes six to eight hours to recharge even with “regenerative braking” added to the EVs system. This limited travel distance per charge and length of recharge time has resulted in the unpopularity and lack of demand for EVs.  
     BRIEF DESCRIPTION OF THE INVENTION  
      In one embodiment, a regenerative charging system is provided that includes a rechargeable power supply and a power regeneration system connected to the rechargeable power supply. The regenerative charging system further includes a controller configured to engage the power regeneration system upon detecting a deceleration condition.  
      In another embodiment, a regenerative charging system is provided that includes a rechargeable power supply and a wind regeneration charging system connected to the rechargeable power supply. The regenerative charging system further includes a controller configured to engage the wind regenerative system upon detecting a predetermined minimum speed.  
      In yet another embodiment, a method for recharging a power supply in a moving object is provided. The method includes determining when the moving object is decelerating and engaging a momentum regenerative charging system upon determining that the moving object is decelerating. Optionally, the method may include engaging a wind regenerative charging system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a block diagram of power regeneration system for a motive application constructed in accordance with an embodiment of the invention.  
       FIG. 2  is a top plan view of a momentum regenerative charging system constructed in accordance with an embodiment of the invention.  
       FIG. 3  is a side plan view of a momentum regenerative charging system constructed in accordance with an embodiment of the invention.  
       FIG. 4  is a front plan view of a momentum regenerative charging system constructed in accordance with an embodiment of the invention.  
       FIG. 5  is a side plan view of a wind regenerative charging system constructed in accordance with an embodiment of the invention.  
       FIG. 6  is a front plan view of a wind regenerative charging system constructed in accordance with an embodiment of the invention.  
       FIG. 7  is a flowchart of a method for regenerative charging in accordance with an embodiment of the invention.  
       FIG. 8  is a block diagram of a wiring system for a momentum regenerative charging system constructed in accordance with an embodiment of the invention in connection with a variable speed drive system.  
       FIG. 9  is a block diagram of a wiring system for a wind regenerative charging system constructed in accordance with an embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural elements or steps, unless such exclusion is explicitly recited. Furthermore, references to “one embodiment” and “an embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.  
      Various embodiments of the invention provide a momentum regenerative charging system. The momentum regenerative charging system includes electrical and mechanical components that utilize the momentum of the vehicle to recharge one or more battery packs. Optionally and/or additionally, a regenerative wind charging system may be provided that includes electrical and mechanical components that generate additional power to charge the one or more battery packs using the power of the wind.  
      As shown in  FIG. 1 , a regenerative charging system, and more particularly a momentum regeneration system  20  is connected to a power supply  22  that may include one or more battery packs. The momentum regeneration system  20  is also connected to an electromagnetic clutch  24  configured to selectively engage and disengage the momentum regeneration system  20  as described in more detail herein. A controller  26  is connected to the electromagnetic clutch  24  and to an electromagnetic clutch  28  configured to selectively engage and disengage a motor  30  from a transmission system  32 . The transmission system  32  may be a variable speed drive system having a plurality of variable speed drive pulleys as described in co-pending U.S. Patent Application having attorney docket number SPLG 11750-1 and entitled “Variable Speed Transmission,” the entire disclosure of which is hereby incorporated by reference herein.  
      The power supply  22  may be configured in different arrangements to provide power to one or more systems or components. For example, in an automobile application, a standard twelve volt battery may be used to power accessories in the automobile, such as, lights, wipers, horn, etc. A separate low voltage (e.g., twelve volt) battery pack may be provided to power non-motor components, such as, the electromagnetic clutches  24  and  28 , relays, processors, a stepper motor, etc. A high voltage (e.g., ninety-six volt) battery pack also may be provided to separately power the motor  30 . It should be noted that the twelve volt batteries may be combined as a single battery. The voltage and amperage of the battery packs may be provided as needed with a plurality of individual batteries (e.g., 6 volts batteries) wired in series, series/parallel combinations, or parallel.  
      Various embodiments of the invention provide a momentum regeneration system  20  including a momentum regenerative charging system  40  as shown in  FIGS. 2 through 4 . The momentum regenerative charging system  40  includes a plurality of alternators  42  (or generators) connected by belts  44  to a plurality of pulleys  45  mounted on a center shaft  46 . More particularly, the shaft  46  is adaptably mounted to a framework, for example, within a vehicle, using bearing mounts  47  such as carrier bearings with the plurality of alternators  42  also mounted to the framework so as to be compatibly coupled with the belts  44  from alternator pulleys  49  to the pulleys  45  on the shaft  46 . An additional pulley (not shown) is provided and compatibly coupled with a belt (not shown) to a pulley on the electromagnetic clutch  24  (shown in  FIG. 1 ), which may be located on a drive shaft of a pulley (e.g., variable speed pulley) of the transmission system  32  closest to the motor  30  (shown in  FIG. 1 ).  
      Each alternator  42  is connectively wired to one or more batteries in the power supply  22  (shown in  FIG. 1 ), for example, to both the high voltage battery packs and low voltage battery packs, to produce a connection of equal nominal voltages between each battery or set of batteries of the battery packs and the rated nominal voltage of each alternator  42 .  
      Optionally and/or additionally, a wind regenerative charging system  50  for power regeneration also may be provided as shown in  FIGS. 5 and 6 . The wind regenerative charging system  50  is illustrated in a vehicle application, but it should be appreciated that the wind regenerative charging system  50  may be used in connection with any type of motive application, for example, a train, airplane, tractor, forklift, golf cart, wheelchair, etc. The wind regenerative charging system  50  includes a plurality of wind turbines  52  positioned at the air intake openings  54  in the grill areas  56  of a vehicle  58  (e.g., electric vehicle). The grill areas  56  are typically located above a bumper  60  with an air intake chamber  62  behind the grill areas  56 . The wind turbines  52  are connected to generators  64  via turbine shafts  66  that are located in an exhaust air chamber  68  extending out of the vehicle  58  through exhaust openings  70 . It should be noted that the wind turbines  52  may be positioned generally above wheel wells  72  of the vehicle  58 .  
      In operation in a motive application (e.g., in a vehicle), when the momentum regenerative charging system  40  is engaged, which occurs in a motive application each time the vehicle decelerates as described below, the momentum regenerative charging system  40  provides power to charge, for example, the power supply  22 , including the both the high voltage and the low voltage battery packs. The momentum regenerative charging system  40  for power regeneration is activated, and in particular, engaged by the electromagnetic clutch  24  as controlled by the controller  26 , during a majority of periods of deceleration without, for example, having to apply the brake pedal in the vehicle. The wind regenerative charging system  50  is activated upon activation of the ignition of the vehicle  58  (e.g., when the ignition key is inserted and turned).  
      More particularly, and referring to  FIG. 1 , the electromagnetic clutch  24  that is adaptably coupled to the transmission system  32  engages and disengages the momentum recharging alternators  42  or generators  64  from the mechanical system of the transmission system  32  (e.g., from the variable speed pulleys or transmission shaft). Accordingly, when the vehicle  58  is accelerating or cruising at any given rate of speed the electromagnetic clutch  28 , namely the drive motor electromagnetic clutch  28  is engaged to the transmission system  32  propelling the vehicle. It should be noted that the generators  64  also may be engaged if a minimum predetermined speed is reached. However, when deceleration occurs beyond a preset or predetermined limit, the controller  26 , which may be a programmable logic computer (PLC), disengages the electromagnetic clutch  28  and engages the electromagnetic clutch  24 , namely the momentum recharging electromagnetic clutch  24 . This operation causes rotation of the shaft  46  that is now engaged with the transmission system  32  (which may be provided via one or more reduction pulleys) and accordingly causes the rotation of the alternators  42 , thereby providing regenerative amperage back into both the high voltage and low voltage battery packs during deceleration.  
      Specifically, once the electromagnetic clutch  24  is engaged thereby rotating the pulley of the electromagnetic clutch  24 , the rotation is transferred through a belt to the shaft  46 , with the shaft  46  rotating the adaptably mounted pulleys  45 . The rotation of the pulleys  45  in turn is transferred through the belts  44  to the plurality of alternators  42 , thereby rotating the alternators  42  and generating power that is provided through wiring into batteries of the battery packs within the power supply  22 . This rotating operation creates additional stored power (e.g., amperage) capable of transporting the vehicle  58 , for example, for an extended period of time and for greater distances. Thus, the regeneration system  20  harnesses the momentum of, for example, an electric vehicle and converts that momentum into regenerative electrical power.  
      It should be noted that with the electromagnetic clutch  24  adaptably coupled to, for example, the pulley in the transmission system  32  that is closest to the motor  30 , the rate of motion remains relatively the same, generating relatively the same amount of power even as the vehicle  58  decreases in speed.  
      It further should be noted that the engagement of the momentum regenerative charging system  40  by the electromagnetic clutch  24  occurs with or without applying the brake pedal  73  (shown on  FIG. 5 ) of the vehicle  58  (shown in  FIG. 6 ), even if deceleration is only occurring, for example, during the time that a vehicle in front of the vehicle  58  is turning into a driveway, or while coasting down a long downhill grade. Thus, the rate of regeneration of power to the battery storage systems of, for example, an electric vehicle is increased (compared to that of conventional “regenerative braking” systems currently incorporated in EVs).  
      Further, in operation, particularly at higher speeds, the wind regenerative charging system  50  is configured to harness the power of wind resistance created with movement of an object, for example, the vehicle  58 . More particularly, the basic equation for energy production through wind generation is: P=ρAV 3 , where “P” is power in Joules, “ρ” is the density of the air, “A” is the area of the propeller that faces the oncoming wind, and “V” is the wind speed in meters per second. The most important term of this relationship is the wind speed “V”. This equation shows that the power in Joules is proportional to the cube of the value of wind speed. This indicates that the power that can be produced from the wind is exponentially larger than the wind speed. For example, if the speed of the wind is two meters per second, the wind power available is eight joules. Accordingly, instead of sealing off the front (usually engine) compartment of the vehicle  58  as is customary in EVs, the opening usually provided for the radiator air flow in internal combustion vehicles is utilized to generate secondary power regeneration, during movement of the vehicle, and particularly at higher speeds, such as during highway travel, where deceleration does not occur as often as during city driving.  
      The wind regenerative charging system  50  essentially forms multiple wind tunnels. As the speed of the vehicle  58  increases, the air flow through the wind tunnels increases thereby increasing the amount of power generated by the generators  64  connected to the wind turbines  52 . This power generation can multiply exponentially so as to provide exponentially more power to the battery packs during the time that the deceleration rate is exponentially lower.  
      Accordingly, various embodiments of the invention provide power regeneration in motive applications. More particularly, as shown in  FIG. 7 , a method  100  for regeneratively charging one or more battery packs, for example, in a vehicle such as an EV, includes at  102  providing power supply to a motor (e.g., connecting a power supply having a plurality of battery packs to a motor) that is engaged to a transmission system to move the vehicle. This power supply is provided when the vehicle is accelerating or maintained at a constant speed, such as coasting and may be determined based on pressure applied to a foot feed (e.g., gas pedal) in the vehicle. For example, a potentiometer may be used to determine a resistance value (e.g., ohm reading) based on depression of the foot feed. A determination is then made at  104  as to whether the vehicle is decelerating, namely, whether there is a deceleration condition. If the vehicle is not decelerating, then the power supply remains connected to the motor  102 . However, if the vehicle is decelerating, then at  106 , a power regeneration system is engaged (to recharge one or more battery packs) and connected to the transmission system with the motor disengaged from the transmission system. The determination of whether the vehicle is decelerating may be based on an ohm reading of the foot feed decreasing below a predetermined limit indicating that a user is reducing speed or removing his or her foot from the foot pedal. Alternatively, or in addition, a similar determination may be made as to whether the user is applying pressure to the brake pedal based on an ohm reading. If a determination is made that either the gas pedal is being released (and cruise control is not activated) or the brake pedal is being depressed, the power regeneration system is engaged and the motor disengaged from the transmission system. The control of the switching may be controlled by a controller, such as a PLC.  
      Thereafter, a determination is made at  108  as to whether acceleration is desired. If acceleration is not desired, for example, if the vehicle continues to decelerates, then the engagement of the power regeneration system is maintained at  110 . However, if a determination is made at  108  that acceleration is desired, then at  112 , the power regeneration system is disengaged and the motor reengaged with the transmission system. The determination of whether acceleration is desired may be based on, for example, detecting that the gas pedal is being depressed.  
      It should be noted that a wind regenerative charging system also may be provided to charge one or more battery packs in the vehicle as described herein.  
      The momentum regenerative charging system  40  and the wind regenerative charging system  50  may be provided in different configurations. One configuration for the momentum regenerative charging system  40  is shown in  FIG. 8  in connection with a variable speed drive transmission. As shown, the power supply  22  may include one or more battery packs  120  connected to the plurality of alternators  42  through breakers  122 . Control mechanisms for controlling and activating the transmission system also may be provided such as a linear actuator controller  124  controlling a linear actuator  126 . Additional measuring components  128  may be provided to determine the speed of the vehicle and a potentiometer  130  may be included to determine different conditions, such as acceleration or deceleration of the vehicle as described herein. A plurality of warning and indicator lights  132  also may be provided, such as, for temperature levels, voltage levels, etc. The battery packs  120  also may be connected to the wind regenerative charging system  50  shown in  FIG. 9 . The battery packs  120  are connected to the generators  64  through breakers  14 .  
      While particular embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the various embodiments of the invention. For example, the number of alternator or generators may be increased or decreased based on the power requirements for the application. The number and power output of the battery packs also may be increased or decreased based on the power requirements for the application. Further, the various embodiments may be implemented in connection with any motive application and are not limited to electric vehicles. For example, in addition to cars, buses, golf carts, urban commuter vehicles, etc., the various embodiments may be implemented in connection with lawn mowers, wheelchairs, etc.  
      Thus, a momentum regenerative charging system is provided that utilizes the momentum of the vehicle to recharge the battery packs upon deceleration of the vehicle. Further, an additional regenerative wind charging system also may be provided that generates additional power to the battery packs by harnessing the power of the wind, particularly at higher vehicle speeds.  
      While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the various embodiments of the invention can be practiced with modification within the spirit and scope of the claims.