Patent Publication Number: US-2016236693-A1

Title: Electric power supply system for machine

Description:
TECHNICAL FIELD 
     The present disclosure relates to an electric power supply system for a machine, and more particularly relates to a method for supplying electric power to electrical components of the machine. 
     BACKGROUND 
     Machines, such as locomotives, on road vehicles and off road vehicles, include an electric power supply system coupled to an engine of the machine. The electric power supply system is provided with a power source, such as a battery. The battery aids in operation of electrical components of the machine and for cranking the engine. The electrical components include a starter motor, an air conditioning unit, a heater, a cabin lighting unit, a high frequency radio, a GPS navigational system, and a lighting unit. The electrical components add to the load which is already handled by the electric power supply system, thereby rendering charge of the electric power supply system insufficient for cranking the engine. In such circumstances, the electrical components may require additional electric power source to be employed in the machine, which in turn adds to the cost of the machine. 
     U.S. Pat. No. 6,928,972 (the &#39;972 patent) describes a system and method for providing auxiliary power to a large diesel engine, and allowing shut down of the engine on various weather conditions. The system discloses an auxiliary power unit comprising a secondary engine coupled to an electrical generator. The system further discloses an automatic control system to shut down the primary engine prior to a period of idling. The auxiliary power unit further provides electrical power for heating and air conditioning. The auxiliary power unit is adapted to automatically start in response to a low coolant temperature, low battery voltage, and low air reservoir pressure. With such arrangement of having the primary engine and the secondary engine, the &#39;972 patent renders the system complex and increases the maintenance cost. 
     SUMMARY OF THE DISCLOSURE 
     According to an aspect of the present disclosure, an electric power supply system for a machine is provided. The electric power supply system includes a first battery configured to communicate with an engine of the machine. The first battery is further configured to supply power to a plurality of electrical components of the machine during an operating state of the engine. The electric power supply system further includes a first contactor disposed between the first battery and the engine. The first contactor is configured to establish an electric communication between the first battery and the engine upon actuation thereof for cranking the engine. The electric power supply system further includes a second battery configured to communicate with the plurality of electrical components of the machine. The second battery is further configured to supply power to each of the plurality of electrical components during a non-operating state of the engine. The electric power supply system further includes a second contactor disposed between the second battery and at least one the plurality of electrical components. The second contactor is configured to establish an electric communication between the second battery and at least one of the plurality of electrical components upon actuation thereof. The electric power supply system further includes a controller in communication with the first contactor and the second contactor. The controller is configured to receive, via a sensing unit, a signal indicative of at least one of the operating state and the non-operating state of the engine. The controller is further configured to determine a state of the engine based on the signal received from the sensing unit. The controller is further configured to actuate at least one of the first contactor and the second contactor to selectively communicate the first battery and the second battery, respectively, with at least one of the engine and the plurality of electrical components based on the determined state of the engine. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a schematic side view of an exemplary machine; 
         FIG. 2  is a block diagram of an electric power supply system for the machine of  FIG. 1 , according to an embodiment of the present disclosure; and 
         FIG. 3  is a flow chart of a method for supplying electric power to electrical components of the machine. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts. Moreover, references to various elements described herein, are made collectively or individually when there may be more than one element of the same type. However, such references are merely exemplary in nature. It may be noted that any reference to elements in the singular may also be construed to relate to the plural and vice-versa without limiting the scope of the disclosure to the exact number or type of such elements unless set forth explicitly in the appended claim. 
       FIG. 1  illustrates a side view of an exemplary machine  10 . For the purpose of illustration, the machine  10  is embodied as a locomotive consist. The term “locomotive consist” referred to herein includes two or more compartments that are mechanically coupled to each other to travel on rails  12 . The “locomotive consist” may be used for transportation of passengers and cargo. It should be understood that the application of the present disclosure is not restricted to the locomotive consist disclosed herein, and may be extended to an off-highway truck, an on-highway truck, a dump truck, an articulated truck, a loader, and any other machine powered by a prime mover, such as an internal combustion engine 
     The machine  10  includes an engine car  14  and a passenger car  16  mechanically coupled to each other. The engine car  14  is embodied as a primary compartment, and includes an operator cabin  18  and an enclosure  20 . The passenger car  16  is embodied as a trail compartment coupled behind the engine our  14  in a propulsion direction of the machine  10 . It should be understood that a number of the engine cars  14  and a number of the passenger cars  16  disclosed herein is exemplary, and may vary based on the application. For example, the machine  10  may include two engine cars  14 . 
     The operator cabin  18  is mounted on a chassis not shown) of the machine  10 . In an example, the operator cabin  18  may include an operator interface (not shown) having control levers, switches, and a display, such that an operator controls movement of the machine  10  and perform various operations of the machine  10 . In addition to the operator cabin  18 , the enclosure  20  is also mounted on the chassis of the machine  10  adjacent to the operator cabin  18 . The enclosure  20  is adapted to house various electrical and mechanical components of the machine  10 . An engine  22  is housed in the enclosure  20  of the machine  10 . In an example, the engine  22  may he one of a diesel engine, a gasoline engine, and a gaseous fuel powered engine, such as a natural gas engine. 
     A starter motor  26  is also housed in the enclosure  20  for cranking the engine of the machine  10 . In an example, the starter motor  26  may include a drive gear (not shown) that may be actuated to engage with a flywheel  36  (shown in  FIG. 2 ) of the engine  22  for cranking the engine  22 . Upon cranking the engine  22 , the drive gear of the starter motor  26  may be disengaged from the flywheel  36  (shown in  FIG. 2 ) to allow continuous operation of the engine  22  to generate mechanical power required for propelling the engine our  14  and provide power to various systems of the machine  10 . More particularly, the mechanical power thus generated is further transferred to each of the drive trains (not shown) of the engine car  14  and an electric power supply system  23  of the machine  10 , On receiving the mechanical power, the drive train delivers rotational power to a set of rail engaging members  24 . The set of rail engaging members  24  assists in movement of the machine  10 . 
     The electric power supply system  23  is housed within the enclosure  20  of the machine  10  and is in electric communication with the engine  22 . The electric power supply system  23  is configured to supply electric power to a plurality of electrical components  25  of the machine  10 . The electric power supply system  23  includes an alternator  28 . The alternator  28  receives a drive power from the engine  22  via a gear drive, a chain drive, or a belt drive. The alternator  28  converts the mechanical power into electric power. 
     The electric power supply system  23  further includes a first battery  30  and a second battery  32  configured to receive the electric power from the alternator  28 . Each of the first battery  30  and the second battery  32  may be one of a lead acid battery, a zinc bromine battery, a nickel zinc battery or any such type of battery known in the art. Further, each of the first battery  30  and the second battery  32  is configured to supply the electric power to each of the plurality of electrical components  25  provided in the operator cabin  18  and the passenger car  16  of the machine  10 . In an example, the plurality of electrical components  25  may include a Heating Ventilation Air Conditioning (HVAC) Unit, control devices and safety devices. In an example, the control devices may include, but not limited to, the operator interface, a high frequency radio, a GPS navigational system, and an automated start/stop system. The safety devices may include, but not limited to, a cabin lighting unit, a headlamp, and a flasher unit. 
     During an operating state of the engine  22 , the engine  22  is adapted to generate mechanical power, and thereupon transfers the generated mechanical power to the alternator  28 . The alternator  28  converts the mechanical power into the electric power. As such, the alternator  28  is configured to charge the first battery  30  and the second battery  32  during the operating state of the engine  21  The first battery  30  and the second battery  32  are configured to store the electric power received from the alternator  28 , and further supply the electric power to the plurality of electrical components  25  provided in the operator cabin  18  and the passenger car  16  of the machine  10 . 
     Further, during a non-operating state of the engine  22 , the second battery  32  is configured to supply the electric power to the plurality of electrical components  25  provided in the operator cabin  18  and the passenger car  16 . The manner in which the first battery  30  and the second battery  32  are operated with respect to the operating state and the non-operating state of the engine  22  is described in  FIG. 2  and  FIG. 3 . 
     Although the present disclosure herein is described with respect to the starter motor  26  for cranking the engine  22 , it will he understood by a person skilled in the art that the electric power supply system  23  may be implemented in any machine having an electric starting system, such as a generator or an invertor for supplying the electric power to the plurality of electrical components  25 . 
       FIG. 2  illustrates a block diagram of the electric power supply system  23 . The electric power supply system  23  is configured to supply the electric power to the starter motor  26  and each of the plurality of electrical components  25  provided in the operator cabin  18  and the passenger car  16  of the machine  10 . In the present embodiment, the plurality of electrical components  25  are categorized as anon-critical load equipment  25 A, such as the HVAC unit, and a critical load equipment  25 B, such as the control devices, and the safety devices. The electric power supply system  23  is configured to supply the electric power to the non-critical load equipment  25 A during the non-operating state of the engine  22  and the critical load equipment  25 B during the operating state and the non-operating state of the engine  22 . 
     The electric power supply system  23  includes a sensing unit  34  for determining a state of the engine  22 . The sensing unit  34  is configured to communicate with the engine  22  of the machine  10 . In an example, the sensing unit  34  may include plurality of sensors to detect various operating parameters of the engine  22 . The plurality of sensors may include a tachometer, a pressure sensor, a temperature sensor and any other sensors known in the art. The sensing unit  34  is configured to receive a signal indicative of various operating parameters of the engine  22 , such as speed, oil pressure and oil temperature. The sensing unit  34  may also be configured to receive a signal indicative of various operations performed by an operator within the operator cabin  18  of the machine  10 . The state of the engine  22 , such as the operating state and the non-operating state is determined based on the signal received from the sensing unit  34 . 
     The first battery  30  is configured to communicate with the starter motor  26  of the engine  22 . Specifically, the first battery  30  is configured to supply the electric power to the starter motor  26  when the engine  22  is in the non-operating state. Upon receiving the electric power from the first battery  30 , the starter motor  26  actuates the drive gear to engage with the flywheel  36  of the engine  22 . As such, the starter motor  26  rotates the flywheel  36  and enables cranking of the flywheel  36  of the engine  22  to generate the mechanical power. After the cranking of the engine  22 , in an example, the first contactor  40  may disconnect the electric communication from the first battery  30  to the starter motor  26  to disengage the drive gear from the flywheel  36 . Further, in an example, the first battery  30  may be configured to provide the electric power to the critical load equipment  25 B during the non-operating state of the engine  22 . 
     The electric power supply system  23  further includes a first contactor  40 . The first contactor  40  is disposed between the first battery  30  and the starter motor  26  of the engine  22 . In an example, the first contactor  40  may be a mechanical push button, or a contact switch that is normally in an open condition. Upon actuation, the first contactor  40  moves to a closed condition to allow supply of electric current therethrough. In the present embodiment, the first contactor  40  is configured to establish an electric communication between the first battery  30  and the starter motor  26  of the engine  22  upon actuation thereof. In various examples, the first contactor  40  may establish or disconnect the electric communication from the first battery  30  to the starter motor  26  irrespective of the state of the engine  22 . In an example, the first contactor  40  may be provided with an electromagnetic coil and a contact. On electrical actuation of the electromagnetic coil, the electromagnetic coil generates a magnetic field and attracts the contact towards the electromagnetic coil. As such the contact allows the supply of the electric power from the first battery  30  to the starter motor  26 . Likewise, on electrical de-actuation of the electromagnetic coil, the electromagnetic coil fails to generate the magnetic field and hence fails to attract the contact towards the electromagnetic coil. As such the contact disconnects supply of the electric power from the first battery  30  to the starter motor  26 . 
     The second battery  32  of the electric power supply system  23  is configured to supply the electric power to the critical load equipment  25 B of the machine  10  during non-operating state of the engine  22 . Further, in an example, the second battery  32  may also be configured to supply the electric power to the critical load equipment  25 B of the machine  10  during the operating state of the engine  22 . The electric power supply system  23  further includes a second contactor  42 , The second contactor  42  is disposed between the second battery  32  and the plurality of electrical components  25  provided in the operator cabin  18  and the passenger car  16 . Construction of the second contactor  42  is similar to the construction of the first contactor  40  described above. In the present embodiment, the second contactor  42  is configured to establish an electric communication between the second battery  32  and the plurality of electrical components  25  upon actuation thereof during the non-operating state of the engine  22 . More specifically, the second contactor  42  is configured to establish the electric communication to supply the electric power to the critical load equipment  25 B during the non-operating state of the engine  22 . In various examples, similar to the first contactor  40 , the second contactor  42  may establish or disconnect the electric communication from the second battery  32  to the plurality of electrical components  25  irrespective of the state of the engine  22 . The electric power supply system  23  further includes a third contactor  44  disposed between the first battery  30  and the critical load equipment  25 B. Such that, upon actuation of the third contactor  44 , the first battery  30  is configured to provide the electric power to the critical load equipment  25 B of the machine  10  irrespective of the state of the engine  22 . 
     The electric power supply system  23  further includes a charging unit  38  in electric communication with the alternator  28 . The alternator  28  supplies the electric power to the plurality of electrical components  25  including the non-critical load equipment  25 A and the critical load equipment  25 B provided in the operator cabin  18  and the passenger car  16  of the machine  10  during operating state of the engine  22 . 
     The charging unit  38  is configured to bifurcate a portion of the electric power from the alternator  28  to each of the first battery  30  and the second battery  32 . As such, the charging unit  38  is configured to charge each of the first battery  30  and the second battery  32  during the operating state of the engine  22 . In addition, the charging unit  38  is configured to supply the electric power to operate the critical load equipment  25 B via a diode  46  and the second contactor  42 , and also to supply the electric power to operate the non-critical load equipment  25 A. The diode  46  enables the supply of the electric power from the charging unit  38  to the critical load equipment  25 B of the plurality of electrical components  25 , and restricts reverse flow of electric current. 
     The electric power supply system  23  further includes a controller  50  configured to selectively supply the electric power to the plurality of electrical components  25  and the starter motor  26  of the engine  22  from the first battery  30  and the second battery  32 . The controller  50  is also in communication with the sensing unit  34  and configured to receive the signal from the sensing unit  34 . Based on the signal received from the sensing unit  34 , the controller  50  determines whether the engine  22  is in the operating state or non-operating state. Based on the state of the engine  22 , the controller  50  is configured to communicate with the first contactor  40 , the second contactor  42 , and the third contactor  44 . in an example, the controller  50  may be a processor including a single processing unit or a number of processing units, all of which may include plurality of computing units. The explicit use of term ‘processor’ should not be construed to refer exclusively to hardware capable of executing a software application. Rather, in this example, the controller  50  may be implemented as one or more microprocessors, microcomputers, digital signal processor, central processing units, state machine, logic circuitries, and any device that is capable of manipulating signals based on operational instructions. Among the capabilities mentioned herein, the controller  50  may also he configured to receive, transmit, and execute computer-readable instructions. 
     in operation of the electric power supply system  23 , the sensing unit  34  may monitor various operating parameters, such as an engine speed, oil pressure, and oil temperature, of the engine  22  to determine the state of the engine  22 . Accordingly, the sensing unit  34  transmits the signal indicative of the operating parameters of the engine  22  to the controller  50 . Upon receiving the signal, if the controller  50  determines that the engine  22  is in the non-operating state, then the controller  50  electrically actuates the first contactor  40 . As described earlier, the electrical actuation of the first contactor  40  allows the supply of the electric power from the first battery  30  to the starter motor  26 . The starter motor  26  initiates the operation of the engine  22 , and thus the mechanical power is generated from the engine  22 . Further, the starter motor  26  causes the engine  22  to move to the operating state thereof. In the operating state of the engine  22 , the engine  22  transfers the mechanical power to the alternator  28 , as such the alternator  28  converts the mechanical power into the electric power. The electric power is in turn supplied to the charging unit  38 . The charging unit  38  is configured to charge each of the first battery  30  and the second battery  32 . As a result, both the first battery  30  and the second battery  32  are preserved with required electric charge. The charging unit  38  further supplies the electric power to the non-critical load equipment  25 A provided in the operator cabin  18  and the passenger car  16  of the machine  10 . 
     In an example, during the operating state of the engine  22 , the controller  50  may electrically actuate at least one of the second contactor  42  and the third contactor  44 . Upon actuation of the at least one of the second contactor  42  and the third contactor  44 , at least one of the first battery  30  and the second battery  32  supplies the electric power to the critical load equipment  25 B provided in the operator cabin  18 . 
     Further, upon receiving the signal, if the controller  50  determines that the engine  22  is in the non-operating state, then the controller  50  electrically actuates the second contactor  42  to meet a demand of the electric power required by the plurality of electrical components  25 , specifically the critical load equipment  25 B. As described earlier, electrical actuation of the second contactor  42  allows supply of the electric power from the second battery  32  to the critical load equipment  25 B during the non-operating state of the engine  22 . 
     Further, in an example, during the non-operating state of the engine  22 , the first contactor  40  and the third contactor  44  may be in the non-actuated condition. The non-actuated condition of the third contactor  44  disconnects supply of the electric power from the first battery  30  to the critical load equipment  25 B. Similarly, in the non-actuated condition, the first contactor  40  disconnects the supply of the electric power from the first battery  30  to the starter motor  26 . As a result, the critical load equipment  25 B provided in the operator cabin  18  and the passenger car  16  receives the electric power from the second battery  32  during the non-operating state of the engine  22 . Further, the first battery  30  remains completely charged during the non-operating state of the engine  22 , to supply the electric power to the starter motor  26  during cranking of the engine  22 . 
     INDUSTRIAL APPLICABILITY 
     The present disclosure relates to the electric power supply system  23  for the machine  10 , and a method  52  of supplying the electric power to the plurality of electrical components  25  of the machine  10 . The charging unit  38  provided in the electric power supply system  23  enables charging of each of the first battery  30  and the second battery  32  during the operating state of the engine  22 . The second battery  32  is configured to supply the electric power to the plurality of electrical components  25  provided in the operator cabin  18  and the passenger car  16  of the machine  10  during the non-operating state of the engine  22 . As such, the electric charge of the first battery  30  is preserved during the non-operating state of the engine  22  to supply the electric power to the starter motor  26  during cranking of the engine  22 . 
       FIG. 3  is a flow chart of the method  52  for supplying the electric power to the plurality of electrical components  25  of the machine  10 , The steps in which the method  52  is described are not intended to be construed as a limitation, and any number of steps can be combined in any order to implement the method  52 . Further, the method  52  may be implemented in any suitable hardware, such that the hardware employed can perform the steps of the method  52  readily and on a real-time basis. 
     For the purpose of illustration, various steps of the method  52  are described in conjunction with  FIGS. 1 and 2 . At step  54 , the method  52  includes receiving the signal indicative of at least one of the operating state and the non-operating state of the engine  22  from the sensing unit  34  by the controller  50 . The sensing unit  34  is in electric communication with the controller  50 . The sensing unit  34  monitors the various operating parameters including, but not limited to, the engine speed, the oil pressure, and the oil temperature of the engine  22 . Accordingly, the sensing unit  34  transmits the signal indicative of the non-operating state or operating state of the engine  22 . At step  56 , the method  52  includes determining the state of the engine  22  based on the signal received from the sensing unit  34 . The controller  50  in communication with the sensing unit  34  receives the signal and determines whether the engine  22  is in the operating state or the non-operating state. At step  58 , the controller  50  actuates one of the first contactor  40  and the second contactor  42  with respect to the state of the engine  22 . During the non-operating state of the engine  22 , the controller  50  actuates the first contactor  40  to allow communication between the first battery  30  and the starter motor  26  of the engine  22  for cranking the engine  22 , Further, during the non-operating state of the engine  22 , the controller  50  actuates the second contactor  42  to selectively communicate the second battery  32  with the plurality of electrical components  25  provided in the operator cabin  18  and the passenger car  16  of the machine  10 . 
     As such, the first battery  30  disclosed in the present disclosure is electrically disconnected by the first contactor  40  during the non-operating state of the engine  22 , The electrical disconnection of the first battery  30  enables preservation of electric charge in the first battery  30 , and thereby enabling the first battery  30  to supply the electric power required by the starter motor  26  for cranking the engine  22 . The second battery  32  disclosed in the present disclosure supplies the electric power required to operate the plurality of electrical components  25  provided in the operator cabin  18  and the passenger car  16  of the machine  10  during the non-operating state of the engine  22 . 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.