Patent Publication Number: US-2012041855-A1

Title: EV charging system with electric vehicle diagnostic

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     FEDERALLY SPONSORED RESEARCH 
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     SEQUENCE LISTING, ETC ON CD 
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     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a diagnostic and maintenance information data collection system that is integrated with an electrical recharging system for plug-in electric vehicles and the like. 
     2. Description of Related Art 
     Plug-in Hybrid Electric Vehicles (PHEV) and all-Electric Vehicles (EV), collectively referred to herein as electric vehicles (EV&#39;s), are becoming available now and will become a significant segment of vehicles on the road in the next few years. For this new market, the availability of support services is the key for the success of the business. From the point of view of owners and drivers of electric vehicles, there will be a need for easy access to battery charging services at a large number of locations in widely distributed fashion in order to extend the operating range of the vehicles. In this regard the charging stations will serve a purpose similar to gas stations that supply internal combustion vehicles, and will need to be as widely available. In addition, due to the various complex control circuits and electric parts inside the EV, it is expected that consumers will desire and benefit from accurate and easily accessible status and service information in order to obtain the maximum reliability of the EV. 
     The traditional way to do preventative maintenance for internal combustion engine vehicles is to schedule an appointment and leave their vehicle at a service garage for an extended time for a the diagnostic and maintenance check via a standardized On Board Diagnostics or OBDII data cable. 
     The basic EV coming into the market will have the capability to be charged by using a standard utility power supply, typically 110VAC/15 A or 240VAC/30 A. It may require one to six hours charging time depending on the electric storage capacity of the car and discharge level of the storage system, which is typically a battery of electrochemical cells. This longer charging time for EV provides a chance to do the EV maintenance check while the EV is receiving electrical re-charging services. Furthermore, access to the onboard diagnostic capabilities of an EV can greatly augment the recharging process, not only in assuring the safety of the recharging process but also in optimizing the recharging rate and current/voltage applied to the battery system. 
     For example, an EV roadster currently available that exemplifies the state of the art is equipped with a 56 KW battery that enables the vehicle to achieve and sustain freeway speeds (top speed 125 mph), and to operate for an extended distance (up to 220 miles), comparable to gasoline-powered vehicles. It may be recharged in approximately 3.5 hours using an input of 240V and 70 amps. However, this charge rate necessarily generates substantial heat in the battery, due to the internal resistance of the battery. Thus it requires a cooling system to maintain safe recharging operation (and to sustain high output power when driving the vehicle, as well). As a result, the vehicle is equipped with a cooling system for the battery, the cooling system including a liquid coolant and heat exchanger similar to an internal combustion engine. This example indicates that many EV&#39;s will require some form of battery cooling in order to achieve the fastest possible recharging, and this necessity has not received sufficient in the prior art. 
     The objective of this invention is to extend additional support services to the EV consumer by integrating additional vehicle service and support interfaces with the electrical vehicle recharging system. The further object is to provide an OBDII or OBDII equivalent diagnostic interface to the consumer and sell the data report to the consumer or alternatively to give the diagnostic report to the customer as an incentive to utilize the recharging service. It is another objective of this invention to deactivate the charging system whenever a fault condition is detected by the charging circuit load or a diagnostic test via the diagnostic interface. It is another objective of this invention to make available, when required, a cooling interface whereby the battery or other energy storage system can be thermally controlled during the charging operation to improve the speed or safety of the charging process. It is another objective of this invention to allow the consumer to remotely access additional support services in cases where the diagnostic interface detects a fault condition. 
     BRIEF SUMMARY OF THE INVENTION 
     This invention generally comprises a diagnostic and maintenance information data collection system that is integrated with an electrical recharging system for plug-in electric vehicles and the like. The system includes an EV charging station which performs the recharging services for the battery of the EV. The EV charging station provides for safe connection and disconnection to the charging system. 
     The charging station also provides a diagnostic interface with the vehicle via an OBDII-type connection or the equivalent or alternatively via a wireless interface, optical interface or an electronic encoding imposed upon the charging current. Optionally a cooling system may be integrated into the charging station to enable thermal control of the energy storage system by providing heating or cooling via a second electrical circuit, or a fluid heat exchange system or by a gas heat exchange system. 
     The charging station may produce a diagnostic test report for the EV that is sold to the vehicle operator, or the report may be provided to the vehicle operator gratis as an incentive to increase utilization of the recharging service. It is significant that the charging station can utilize the diagnostic information to determine if the charging process can begin or continue safely according to the real-time sensor readings of the EV, so that recharging is carried out safely and optimally. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is the concept drawing for the basic components for the Charging station. 
         FIG. 2  is a block diagram of the major systems of the electric vehicle and the charging station, showing their functional relationships during the recharging process. 
         FIG. 3  is a flow chart depicting the steps carried out in using the electric vehicle charging system of the invention to recharge the vehicle battery. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention generally comprises a diagnostic and maintenance information data collection system that is integrated with an electrical recharging system for plug-in electric vehicles and the like. 
     Referring to  FIG. 1 , which depicts the main physical components of invention, the main power supply is either from utility power grid  11 , or alternative energy source  12 , or the combination of both. The alternative energy source  12  can be any or all of the following sources: photovoltaic solar cell, wind power, tidal power, solar collector/steam turbine, etc. The main power supply will provide the daily power consumption for the facility, and also connect to the EV charging station  14 . The charging station  14  will provide the charging service to the EV  15  via a cable set  16 . The EV  15  may be an electric-only vehicle or a hybrid internal combustion\electric vehicle which consumes a gas or liquid fuel to supplement the electrical power system, or a steam\electric vehicle. 
     During the time EV  15  is recharging, the charging station  14  will initiate a diagnostic check with the EV  15  by communicating with the sensors and microprocessors inside the EV. The cable set  16  conveys charging current and may optionally include a data path between the charging station  14  and the EV  15  for charging control and diagnostic purposes, as described in detail below. A computer control system  13  is connected to the EV  15 , either through the cable set  16  or by other wired or wireless data transmission devices known in the prior art. 
     With regard to  FIG. 2 , the EV  15  generally includes an electric propulsion motor  21 , a battery  22  of electrochemical cells, and a motor control system  23  connected therebetween to apply electrical power to the motor and propel the vehicle in response to the commands of the vehicle driver. The vehicle  15  also includes an assortment of sensors  24 , including, notably, sensors that detect operational parameters such as battery temperature, battery state of charge, and the like. The sensors are connected to an onboard data bus  26 , such as an ODB or ODB II or CAN known in the prior art. 
     The charging station  14  is provided with a vehicle diagnostics facility  31  that is connected to the onboard data bus  26  via a data link  32 . The data link  32  may comprise a typical data path of any acceptable IEEE standard, including but not limited to an IEEE 802.01x or Bluetooth wireless connection, an IEEE 1394 or USB 2.0 or 3.0 cable, or the like. Alternatively, the data may be encoded and transmitted through the charging cable  16 . The vehicle diagnostics facility  31  is connected to a diagnostic report unit  33  that can print a report detailing the state of the vehicle (motor, battery, subsystems, fault messages saved in the vehicle microprocessor memory, etc.) The unit  33  is connected to the charging station billing system  36 , so that the report may be sold to the vehicle operator or given to the operator as a value-added service to encourage return business. 
     The charging station  14  also includes a charging voltage and current control  34  that is connected to the vehicle battery  22  through the cable  16 . The control  34  is also connected to receive inputs from the vehicle diagnostic unit  31 , and to output charging date to the billing system  36  for the purpose of tracking and summing the energy cost of the recharging service delivered to the vehicle  15 . In addition, a battery cooling unit  37  is connected to the vehicle  15  and receives real-time data from the onboard data bus  26  of the vehicle through the diagnostics facilities  31  and  33 . The battery cooling unit  37  may include a device to introduce air or gas coolant into the battery compartment of the vehicle  15 , or an electric line to power a fan or thermoelectric device in the battery compartment. Alternatively, the battery cooling system may comprise a unit that activates the onboard battery cooling system of the vehicle  15  (for example, through the onboard data bus  26 ) to exchange heat with the energy storage components within the EV and maintain the storage component at a temperature to optimize the safety or charging rate of the storage component. 
     With regard to  FIG. 3 , there is described a method for utilizing the recharging facility depicted in  FIG. 2 . The first step  41  requires connecting the vehicle  15  to the charging station  14 , using the cable  16  and the data transmission link  32  as described above. In step  42  the charging system  14  accesses the vehicle data bus  26 , and identifies (step  43 ) the vehicle (type, battery system, and the like). This step is necessary to determine if the vehicle is capable of being recharged by the charging station  14 . Thereafter, in step  44 , the charging system performs an initial vehicle diagnostic analysis to determine, among other parameters, the state of charge of the battery  22 , and to predict the amount of time required to recharge the battery fully. This step is important in apprising the vehicle owner of the expected service time, and to enable the operator of the charging station to plan for space utilization and power consumption within the station. If a peak power pricing scheme is being implemented, this step may enable the charging station operator to schedule the recharging service for optimal owner convenience (quickest charge possible), or for optimal price (delayed recharging until less expensive power supply time slot). 
     After the vehicle owner agrees to the recharging service (time and price), the battery charging step  47  is begun. During the recharging period, the system also monitors the battery state of charge and temperature (step  48 ). This step enables the battery charging system to adjust the charging voltage and current applied to the battery  22 , whereby the battery temperature is held within its specifications, assuring safety during the process. In addition, the battery cooling system  37  is activated (step  49 ) to respond to the battery temperature and cool the battery and remove as much heat from the battery as is practical. The combination of adjusting the charging voltage and current, and activating the battery cooling system, enables the recharging station to carry out the optimal battery recharging, in terms of speed of recharging and maintaining a safe temperature within the battery  22 . 
     In the final steps  50  and  51 , the vehicle diagnostic report is produced (printed or transmitted electronically or visually), and the billing system  36  interacts with the vehicle owner to debit the owner for the charging service, through a cash/debit/credit transaction as is customary in prior art vehicle service stations. The vehicle  15  is then driven away from the charging station to make it available for the next customer. Clearly, multiple vehicles may undergo recharging simultaneously to make the most effective use of the charging station facilities. 
     The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and many modifications and variations are possible in light of the above teaching without deviating from the spirit and the scope of the invention. The embodiment described is selected to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as suited to the particular purpose contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.