Abstract:
A high voltage battery for a motor vehicle and which includes cells and a system for controlling and monitoring the cells and the functioning of the battery system.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority 35 U.S.C. §119 to European Patent Application No. EP 121 80 280.5 (filed on Aug. 13, 2012), which is hereby incorporated by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    Embodiments relate to a high voltage battery system for a motor vehicle, composed of cells and components for controlling and monitoring the cells and the functioning of the battery system. The cells are connected via high voltage lines and a high voltage interface to devices arranged outside the battery system, such as, in particular, a power converter. A metallically conductive screening plate, in particular, in the form of a housing, is assigned at least to the components and configured to control and monitor the functioning of the battery system. The lines of the high voltage interface which lead to the outside are led through common-mode interference dampers. 
       BACKGROUND 
       [0003]    High voltage battery systems are composed of battery cells and a multiplicity of components. A battery system with Li-ion cells usually requires an electronic controller which monitors the cell voltage and the temperature, determines the operating voltage, the insulation resistance and the state of charge of the system and, if appropriate, controls disconnection devices. In the case of use in electrical or hybrid motor vehicles, the energy of the battery is transferred by a power converter to one or more electric machines, or vice versa (fed back). The power converter generates in this context a PWM alternating current (AC) from the direct current (DC) of the battery by way of power transistors. 
         [0004]    As a result of the high-frequency control of the power transistors in the power converter, interference signals occur on the DC lines between the battery and the power converter. Such interference signals can also be generated by a charging device or a DC/DC converter which is connected to the high voltage bus. It is known to arrange such battery systems in a closed housing. This serves, on the one hand, to protect the battery components against external influences, and on the other hand to protect the surroundings from the voltage which is present inside the battery. The electronic control units are usually arranged inside the battery housing. Interference signals are also generated by the switching processes of these control units. 
         [0005]    As described, the components of a battery are subjected to interference signals which are external to the battery as well as to interference signals which are internal to the battery. These interference signals can have a considerably adverse effect on the functional capability of the battery system. The high-frequency interference signal, which starts, for example, from a power converter, has a considerable adverse effect on, in particular, the sensing of the system voltage. Electronic units can also be damaged by particularly high voltage peaks. 
         [0006]    DE 10 2008 041 518 A1 describes an accumulator monitoring system with a potential isolating circuit for connecting a data processing circuit and a sensing circuit. 
         [0007]    DE 10 2010 029 461 A1 presents direct current source arrangements with coupling to a housing and using capacitors and EMI filters. 
         [0008]    A device for controlling and monitoring direct voltage sources connected in series is presented in DE 10 2010 030 353 A1. Each direct voltage source is assigned a cell monitor. Galvanic decoupling of the cell monitor and central control unit is carried out by way of an isolation module. 
         [0009]    DE 36 26 593 A1 discloses a device for accommodating a battery and electronics in a screening fashion. The electronics are accommodated in the battery housing. 
         [0010]    DE 601 33 613 T2 describes the screening of a high voltage part, and DE 11 2008 003 519 T5 discloses the use of drilled cables in a bidirectional energy management system. 
       SUMMARY 
       [0011]    Embodiments relate to a high voltage battery system having an enhanced design when compared to the known solutions. 
         [0012]    In accordance with embodiments, a high voltage battery system for a motor vehicle includes at least one of: cells connected via high voltage lines and a high voltage interface to one or more devices arranged outside of the battery system (such as, for example, a power converter); components configured to control and monitor the cells and the functioning of the battery system; a housing having a metallically conductive screening plate which accommodates at least the components, wherein the lines of the high voltage interface which lead to the outside are led through common-mode interference dampers. 
         [0013]    In accordance with embodiments, a high voltage battery system includes at least one of: cells which are connected in series or in parallel and which are coupled to components, which are arranged inside the battery system and configured to control and monitor the operation/functioning of the battery system, wherein the cells are connected via high voltage lines to one or more devices arranged outside the battery system (such as, for example, a power converter); a a housing having a metallically conductive screening plate in which accommodates at least the components, wherein the high voltage lines which lead to the outside are led through common-mode interference dampers, and the high voltage interfaces are connected via capacitors to the housing. 
         [0014]    In accordance with embodiments, a high voltage battery for a motor vehicle includes at least one of: a housing; a plurality of cells connected via high voltage lines and a high voltage interface to one or more devices arranged outside of the high voltage battery system; a system configured to control and monitor the status of the cells and; a metallically conductive compartment within the housing and configured to accommodate at least parts of the system, wherein lines of the high voltage interface which lead to outside of the high voltage battery system are led through common-mode interference dampers. 
         [0015]    In accordance with embodiments, a high voltage battery system for a motor vehicle includes at least one of: a housing; a plurality of cells which are connected in series and which produce a high voltage connected to an output; a battery control unit having: (i.) battery modules arranged at each respective cell and configured to sense an operating state of the respective cell, (ii.) a first battery module controller; (iii.) a second battery module controller, wherein the first and second battery module controllers are connected via daisy chains to the sensors; and (iv.) a central unit which is galvanically isolated and operatively connected to the first battery module controller and the second battery module controller, and a metallically conductive housing part configured to accommodate the battery control unit. 
         [0016]    In accordance with embodiments, a high voltage battery system for a motor vehicle includes at least one of: a housing; a plurality of cells configured to produce a high voltage and connected via high voltage lines and a high voltage interface to one or more devices arranged outside of the high voltage battery system; a battery control unit configured to control and monitor the status of the cells; a metallically conductive housing part configured to accommodate the battery control unit; and common-mode interference dampers configured to lead lines of the high voltage interface which to the one or more devices outside of the high voltage battery system. 
         [0017]    In accordance with embodiments, an electronic unit includes a battery control unit configured to monitor the overall state of the battery system and control, for example, the equalization of charge between the battery cells. The battery control unit is arranged inside the battery housing and is covered by way of a dedicated screening plate, and is arranged in a dedicated metallically conductive housing part inside the battery housing. 
         [0018]    In accordance with embodiments, a second electronic unit includes a battery module control unit configured to sense, in particular, the states such as the cell voltage of each individual battery cell and the temperature of at least individual battery cells, and passes on corresponding signals to the Battery Management Unit (BMU). The battery module control unit is connected via a screened line to the battery control unit, wherein the coupling to the battery control unit, which may occur via optocouplers or an inductive coupling, is galvanically disconnected. 
         [0019]    In accordance with embodiments, both the battery control unit and the battery module control unit are screened and/or arranged in a disconnected housing inside the battery housing. 
         [0020]    In accordance with embodiments, a current sensor inside the battery screen or the battery housing is connected via screened and/or twisted lines to the battery control unit. 
         [0021]    The high voltage taps via which the battery control unit senses the voltage of the high voltage battery system are also of screened design. 
         [0022]    In accordance with embodiments, disconnection devices for the high voltage interface and the pre-charging circuit are connected to the battery control unit via twisted lines and/or the specified components are activated and controlled by the battery control unit by way of lines which are twisted in such a way. 
         [0023]    In accordance with embodiments, temperature sensors configured to sense the temperature at defined locations on the high voltage cells, and further sensors configured to sense the temperature of the cooling fluid, are also connected to the battery control unit via twisted lines. 
         [0024]    In accordance with embodiments, additional battery module control units are connected to the battery module control unit in accordance with the daisy chain principle of a serial circuit. The connecting lines are twisted here and/or screened lines are used. In the case of screened lines, series capacitors are provided. 
         [0025]    In accordance with embodiments, a capacitor is provided between the positive and the negative of the high voltage lines. In addition, arresting capacitors are used between the battery housing and the earth of the battery control unit. 
     
    
     
       DRAWINGS 
         [0026]    Furthermore, an exemplary embodiment of the invention will be explained with reference to the drawings. 
           [0027]      FIG. 1  illustrateS a high voltage battery system for a motor vehicle, in accordance with embodiments. 
           [0028]      FIG. 2  illustrates a high voltage battery system for a motor vehicle, in accordance with embodiments. 
       
    
    
     DESCRIPTION 
       [0029]    As illustrated in the drawings, a high voltage battery system has a plurality of cells CM which are connected in series and provide the corresponding high voltage. This high voltage is connected to the output DCDC and is supplied, in particular, to a power converter (not illustrated). A central unit ZE of the battery control unit BMU is galvanically isolated and connected in particular via optocouplers OK (or by way of an inductive coupling) to a first battery module controller CSC bus low and a second battery module controller CSC bus high. 
         [0030]    The battery module controllers CSC bus low and CSC bus high are connected via two daisy chains to CSC components arranged at the cells CM, modules CSC, via which different variables may be sensed, for example, the voltage and/or temperature of individual cells CM. A high signal rate can be achieved by way of the two daisy chains and the battery module controllers CSC bus low and CSC bus high. 
         [0031]    The described battery control unit BMU is accommodated in a separate, screened housing part GHT within the housing GH of the high voltage battery system. An arresting capacitor AK is connected between the battery housing GH and the ground of the battery control unit BMU. 
         [0032]    As illustrated in  FIG. 1 , a device having a shunt resistor is provided as the current sensor IS, which device is connected to the battery module controller CSC bus low. By virtue of the necessary galvanic isolation, the sensor line leads to the galvanically disconnected section of the BMU, the battery module controller CSC bus low. The connection of the current sensor IS to the battery module controller CSC bus low is made via a screened and/or twisted line system. 
         [0033]    As illustrated in  FIG. 2 , a device which has a Hall sensor is provided as the current sensor HS, which device is connected to the central unit ZE of the battery control unit BMU. Since no galvanic isolation is necessary any more by virtue of the magnetic measurement, the sensor line leads, in a screened and/or twisted form, directly to the central unit of the BMU. Basically, the sensing of current can also be carried out with a redundant system. 
         [0034]    As illustrated in  FIGS. 1 and 2 , a plurality of switching mechanisms SM, via which the voltage of the cells ZE which are connected in series can be fed to the output DCDC, are provided in the load path. The switching mechanism SM may be activated via the central unit ZE of the battery control unit BMU and connected to said central unit ZE correspondingly by way of a screened and/or twisted line system. 
         [0035]    Furthermore, in accordance with embodiments voltage taps SAG may be provided at three points on the load path. The voltage values of these taps SAG are connected to the battery module controller CSC bus low and are fed thereto via a screened and/or twisted line system. 
         [0036]    The lines of the output DCDC are each led through ferrite rings (or Vitroperm cores) as common-mode interference dampers GTD inside another battery housing part GHI and are led away to the ground of the high voltage battery system in conjunction with capacitors K. A capacitor K is also connected between the two high voltage lines. 
         [0037]    Although embodiments have been described herein, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 
       List of Reference Signs 
       [0000]    
       
         DCDC output, interface for high voltage 
         BMU battery control unit 
         ZE central unit of the BMU 
         OK optocoupler, inductive coupling 
         CM high voltage cell 
         AK arresting capacitor 
         TS isolating switch 
         CSC device for sensing variables such as temperature, voltage 
         CSC bus high battery module controller 
         CSC bus low battery module controller 
         IS current sensor shunt 
         HS current sensor Hall 
         SAG voltage tap of high voltage line, load path 
         SM switching mechanism of high voltage line, load path 
         GTD common-mode interference damper, ferrite core, Vitroperm core 
         GH main housing of battery system 
         GHT housing part, screening 
         GHI housing part, screening 
         K capacitor