Abstract:
A battery management apparatus is provided. The battery management apparatus is used for increasing the capability of controlling the quality of battery modules and increasing the system integration. The battery management apparatus includes an interchangeable battery module and a battery pack management unit. The interchangeable battery module includes a battery management unit, a relay and a battery cell package. The battery management unit includes a voltage measurement circuit and a memory circuit. The voltage measurement circuit and the memory circuit are insulated from each other. The relay is used for switching an internal circuit of the interchangeable battery module. The battery cell package is connected with the battery management unit, and serves as a power source of the battery management apparatus. The battery pack management unit is connected with the voltage measurement circuit of the interchangeable battery module. The voltage measurement circuit is powered by the battery cell package. The voltage measurement circuit issues voltage information to the battery pack management unit. A battery operation data is stored in the memory circuit. The memory circuit is only accessible by the battery pack management unit through a memory input/autput connector.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a battery management apparatus, and more particularly to a battery management apparatus that utilizes plural battery modules having independent and segregated memory circuits. 
       BACKGROUND OF THE INVENTION 
       [0002]    Nowadays, electric vehicles start to replace fossil fuel vehicles. In addition, electric vehicles are gradually applied to the public transportation field. One of many feasible methods of implementing the electric-powered system to the public transportation vehicles is to use swappable battery packs and battery swap stations. For example, the battery packs in the battery swap stations are fully charged at first. When the battery pack of an electric bus is nearly depleted, the electric bus stops at a specified battery swap station. Then, the depleted battery pack of the electric bus and the fully-charged battery pack of the battery swap station are exchanged with each other within 5 to 10 minutes. Consequently, the electric bus can acquire sufficient electric power from the fully-charged battery pack to be continuously driven. 
         [0003]    In practice, each battery cell in a battery module of the battery pack degrades at different rates during its service time. Moreover, the capacity of each battery module inevitably deteriorates after the third year of the service time. The deterioration of the battery capacity causes a mileage reduction up to about thirty percent. For allowing the battery pack to discharge electricity uniformly, all battery modules of the battery pack have to be kept at a similar capacity range and at a similar internal resistance range. Regardless of the age of battery module, any degraded battery module of the battery pack needs to be replaced with the new one. For realizing the status of the battery module, it is necessary for the battery pack provider to frequently test the battery module. After the capacity of the battery module is predicted and the status of the battery pack is realized, the battery pack provider can provide good service to the electric bus agency and the electric taxi agency. 
         [0004]    Conventionally, the battery module is retested in a specialized facility. After the battery module is retested, it is necessary to download and transfer the operation data, the SOH (state of health) data, the SOC (state of charge) and the usage histories of the substituted battery module or the newly-installed battery module from a battery pack management unit or an electronic control unit (ECU). As known, this process is time-consuming and costly to the battery pack provider. 
         [0005]    Moreover, when a fault event of the battery module occurs, a surge current generates. The surge current may destroy the battery cell and damage the battery management unit. Under this circumstance, the operation data of the battery module stored in the battery management unit are unrecoverable. That is, the user of the battery module cannot acquire the operation data of the battery module. 
         [0006]    Therefore, there is a need of providing a battery management apparatus to overcome the drawbacks of the conventional technology such as the damage of the battery management unit from surge current, the unrecoverable operation data of the battery module and the time-consuming process of acquiring the state of the battery module. 
       SUMMARY OF THE INVENIION 
       [0007]    An object of the present invention provides a battery management apparatus for providing reliable and efficient data transfer between an electronic control unit, a charging system and battery modules. 
         [0008]    Another object of the present invention provides a battery management apparatus capable of recording the operation data and the usage histories of the battery module even if the electromechanical system of an electronic vehicle or the battery module malfunctions. Consequently, the battery service station can track the manufacturing defects and monitor the quality and performance of the leased battery module. 
         [0009]    A further object of the present invention provides a battery management apparatus capable of individually providing the operation data and the usage histories of the battery modules to the battery service station and effectively comparing the operation data and the usage histories of the battery modules when the battery modules are charged. Consequently, the states of all battery modules are inspected. 
         [0010]    In accordance with an aspect of the present invention, there is provided a battery management apparatus. The battery management apparatus includes an interchangeable battery module and a battery pack management unit. The interchangeable battery module includes a battery management unit, a relay and a battery cell package. The battery management unit includes a voltage measurement circuit and a memory circuit. The voltage measurement circuit and the memory circuit are insulated from each other. The relay is used for switching an internal circuit of the interchangeable battery module. The battery cell package is connected with the battery management unit, and serves as a power source of the battery management apparatus. The battery pack management unit is connected with the voltage measurement circuit of the interchangeable battery module. The voltage measurement circuit is powered by the battery cell package. The voltage measurement circuit issues a voltage information to the battery pack management unit. A battery operation data is stored in the memory circuit. The memory circuit is only accessible by the battery pack management unit through a memory input/output connector. 
         [0011]    The above contents of the present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  schematically illustrates the architecture of a battery management apparatus for an electric vehicle according to an embodiment of the present invention; 
           [0013]      FIG. 2  schematically illustrates the detailed circuitry of the architecture of the battery management apparatus as shown in  FIG. 1 ; and 
           [0014]      FIG. 3  schematically illustrates the detailed circuitry of the architecture of the battery management apparatus according to the embodiment of the present invention, in which the battery management apparatus is connected with a charging system. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0015]    The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of preferred embodiments of this invention are presented herein for purpose of illustration and description only. In the following embodiments and drawings, the elements irrelevant to the concepts of the present invention are omitted and not shown. 
         [0016]      FIG. 1  schematically illustrates the architecture of a battery management apparatus for an electric vehicle according to an embodiment of the present invention. As shown in the drawing, the battery management apparatus  100  comprises an outer shell (not shown), a battery pack management unit  102  and plural interchangeable battery modules  130 . The outer shell (not shown) of the battery management apparatus  100  provides an accommodation space for accommodating the battery pack management unit  102  and plural interchangeable battery modules  130 . Preferably hut not exclusively, the battery management apparatus  100  is a battery pack. Each interchangeable battery module  130  comprises a battery cell package  125  and a battery management unit  101 . In this embodiment, the battery management apparatus  100  comprises four interchangeable battery modules  130 . It is noted that the number of the interchangeable battery modules  130  may be varied according to the practical requirements. The battery pack management unit  102  is connected with the battery management units  101 , the positive relays  108  (see  FIG. 2 ) and the negative relays (see  FIG. 2 ) of the plural interchangeable battery modules  130 . When the battery management apparatus  100  is connected with an electrical vehicle, the battery management apparatus  100  is connected with an electric control unit  103  of the electric vehicle through the battery pack management unit  102 . Alternatively, when the battery management apparatus  100  is connected with a charging system  201  (see  FIG. 3 ), the battery management apparatus  100  is connected with the charging system  201  through the battery pack management unit  102 . The detailed connections between these components will be described later. 
         [0017]    Please refer to  FIG. 1  again. The battery cell package  125  of each interchangeable battery module  130  is connected with the corresponding battery management unit  101 . Moreover, the battery cell package  125  is the electric power source of the interchangeable battery module  130 . The battery management unit  101  comprises a voltage measurement circuit  106  and a memory circuit  104 . The voltage measurement circuit  106  and the memory circuit  104  are insulated from each other. Preferably but not exclusively, the memory circuit  104  is a non-volatile memory circuit. The battery management unit further comprises an isolation circuit  105 . Preferably but not exclusively, the isolation circuit  105  is an optocoupier. In this embodiment, the isolation circuit  105  is arranged between the battery pack management unit  102  and the voltage measurement circuit  106 . Due to the isolation circuit  105 , the battery pack management unit  102  and the voltage measurement circuit  106  are electrically insulated from each other. However, signals can be transmitted between the battery pack management unit  102  and the voltage measurement circuit  106 . The memory circuit  104  is used for storing the operation data of the interchangeable battery module  130 . Moreover, the memory circuit  104  is only accessible by the battery pack management unit  102 . Consequently, the battery operation data and the usage histories of the interchangeable battery module  130  are continuously accumulated and stored by the memory circuit  104 . 
         [0018]    In this embodiment, each battery management unit  101  is further divided into a first section  101   a  and a second section  101   b . The voltage measurement circuit  106  and the isolation circuit  105  of the battery management unit  101  are included in the first section  101   a.  The memory circuit  104  of the battery management unit  101  is individually included in the second section  101   b . Since the first section  101   a  and the second section  101   b  are segregated and insulated from each other, the voltage measurement circuit  106  and the memory circuit  104  in the two different sections are also insulated from each other. The voltage measurement circuit  106  in the first section  101   a  is connected with the battery pack management unit  102  through the isolation circuit  105  and an instruction I/O connector  127 . Consequently, the voltage information of the interchangeable battery module  130  is provided to the battery pack management unit  102 . The voltage information is processed by the battery pack management unit  102  and converted into battery operation data, including the state of charge (SOC) information, the state of health (SOH) information, the cell temperature history information, the current usage information, the vehicle location history information, and so on. The memory circuit  104  in the second section  101   b  of the battery management unit  101  is connected with the battery pack management unit  102  through a memory I/O connector  126 . The memory circuit  104  is connected with the battery pack management unit  102  only, but not connected with other circuits. Consequently, the memory circuit  104  is only accessible by the battery pack management unit  102  through the memory I/O connector  126 . Moreover, the electric power for powering the voltage measurement circuit  106  in the first section  101   a  is provided by the battery cell package  125 , and the electric power for powering the memory circuit  104  in the second section  101   b  is provided by a low voltage source (not shown) through the memory I/O connector  126 . 
         [0019]    The connection status of the battery management apparatus  100  used in the electric vehicle and the connection status of the battery management apparatus  100  in a charged mode will be illustrated as follows. 
         [0020]      FIG. 2  schematically illustrates the detailed circuitry of the architecture of the battery management apparatus as shown in  FIG. 1 . As shown in  FIG. 2 , the battery management apparatus  100  comprises the battery pack management unit  102  and the plural interchangeable battery modules  130 . For succinctness, only one interchangeable battery module  130  of the battery management apparatus  100  is shown in the drawing. It is noted that the number of the interchangeable battery modules  130  is not restricted. The interchangeable battery module  130  comprises the battery cell package  125 , the battery management unit  101 , the positive relay  108  and the negative relay  109 . In this embodiment, the battery cell package  125  comprises plural battery cells  1251 ,  1252 ,  1253 ,  1254  and  1255  in order to provide electric energy to the interchangeable battery module  130 . The number of the battery cells in the battery cell package  125  may be varied according to the practical requirements. That is, the number of the battery cells in the battery cell package  125  is not restricted. As mentioned above, the battery management unit  101  comprises the voltage measurement circuit  106 , the isolation circuit  105  and the memory circuit  104 . The battery management unit  101  is divided into the first section  101   a  and the second section  101   b,  which are segregated from each other. The voltage measurement circuit  106  and the isolation circuit  105  of the battery management unit  101  are included in the first section  101   a.  The memory circuit  104  of the battery management unit  101  is included in the second section  101   b . Consequently, the voltage measurement circuit  106  and the memory circuit  104  are segregated and insulated from each other. 
         [0021]    The positive relay  108  and the negative relay  109  are connected with a positive electrode and a negative electrode of the battery cell package  125 , respectively. Preferably but not exclusively, the positive relay  108  is connected with the positive electrode of the battery cell  1251  of the battery cell package  125 , and the negative relay  109  is connected with the negative electrode of the battery cell  1255  of the battery cell package  125 . Consequently, the circuitry status of the interchangeable battery module  130  is controllable. In the battery management apparatus  100 , the battery pack management unit  102  is connected with the positive relay  108  and the negative relay  109  through two relay control connectors  128 . Consequently, the positive relay  108  and the negative relay  109  are controlled to be in a closed state or an open state. In this embodiment, the positive relay  108  and the negative relay  109  are further connected with a battery module positive electrode  110  and a battery module negative electrode  111 , respectively. Consequently, the battery management apparatus  100  can be connected with the electric vehicle or the external power source (e.g., the charging system  201  as shown in  FIG. 3 ) so as to provide electric power or receive electric power. 
         [0022]    The relationships between the battery pack management unit  102  and associated components will be illustrated as follows. Please refer to  FIG. 2  again. The battery pack management unit  102  is connected with the isolation circuit  105  and the voltage measurement circuit  106  in the battery management unit  101  of the interchangeable battery module  130  through the instruction I/O connector  127 . Moreover, the isolation circuit  105  is arranged between the voltage measurement circuit  106  and the battery pack management unit  102 . Due to the isolation circuit  105 , the voltage measurement circuit  106  and the battery pack management unit  102  are electrically insulated from each other. However, signals can be transmitted between the voltage measurement circuit  106  and the battery pack management unit  102 . The battery pack management unit  102  is connected with the memory circuit  104  in the battery management unit  101  of the interchangeable battery module  130  through the memory I/O connector  126 . Moreover, the electric power for powering the memory circuit  104  is provided by a low voltage source (not shown) in the battery pack management unit  102 . Moreover, the memory circuit  104  is only accessible by the battery pack management unit  102 . As mentioned above, the battery pack management unit  102  is connected with the positive relay  108  and the negative relay  109  of the interchangeable battery module  130  through the two relay control connectors  128 . Consequently, the battery pack management unit  102  can adjust the circuitry statuses of the positive relay  108  and the negative relay  109  through the relay control connectors  128 . When the battery management apparatus  100  is connected with the electric vehicle, the battery pack management unit  102  is connected with the electric control unit  103  of the electric vehicle through a battery I/O connector  124 . Consequently, the battery operation data and the usage histories of the interchangeable battery module  130  can be transmitted from the battery pack management unit  102  to the electric control unit  103 . 
         [0023]    When the battery management apparatus  100  of the present invention is applied to the electric vehicle, the battery pack management unit  102  continuously receives the voltage information from the voltage measurement circuit  106  of the battery management unit  101  through the instruction I/O connector  127 . After the voltage information is processed, the battery pack management unit  102  acquires a series of battery operation data. Then, the battery pack management unit  102  stores the battery operation data into the memory circuit  104  through the memory I/O connector  126 , or provides the battery operation data to the electric control unit  103  of the electric vehicle through a battery I/O connector  124 . Moreover, the memory circuit  104  of the battery management unit  101  is an independent and insulated component that is included in the battery management unit  101  and externally powered. That is, the battery management unit  101  of the interchangeable battery module  130  cannot directly read or access the memory circuit  104 . If the interchangeable battery module  130  has a malfunction, the generated surge current may only destroy the battery cell package  125  of the interchangeable battery module  130  and the voltage measurement circuit  106  in the first section  101   a  of the battery management unit  101 . Since the first section  101   a  and the second section  101   b  of the battery management unit  101  are segregated. and insulated from each other, the memory circuit  104  in the second section  101   b  of the battery management unit  101  is not attacked by the surge current. Under this circumstance, the battery operation data stored in the memory circuit  104  are not lost. In other words, the memory circuit  104  has functions similar to a black box of an airplane. 
         [0024]      FIG. 3  schematically illustrates the detailed circuitry of the architecture of the battery management apparatus according to the embodiment of the present invention, in which the battery management apparatus is connected with a charging system. The battery management apparatus  100  as shown in  FIG. 2  is connected with the electric control unit  103  of the electric vehicle. Whereas, the battery management apparatus  100  as shown in  FIG. 3  is connected with the charging system  201 . Except for the following items, the architecture of the battery management apparatus  100  is similar to that mentioned above. Please refer to  FIG. 3 . During a charging operation, the battery pack management unit  102  is connected with the charging system  201  through the battery I/O connector  124 . Consequently, the battery pack management unit  102  and the charging system  201  are in communication with each other. The charging system  201  further comprises a positive charging terminal  202  and a negative charging terminal  203 . The positive charging terminal  202  and the negative charging terminal  203  are respectively connected with the battery module positive electrode  110  and the battery module negative electrode  111  of the battery management apparatus  100 . Consequently, the interchangeable battery module  130  of the battery management apparatus  100  can be charged by the charging system  201 . Since the battery operation data of the interchangeable battery module  130  is stored in the memory circuit  104  of the interchangeable battery module  130 , the charging system  201  can directly read the battery operation data of the interchangeable battery module  130  through the battery pack management unit  102  of the battery management apparatus  100 . Consequently, while the battery management apparatus  100  is being charged, the battery pack provider can test the electrical characteristics of all battery modules  130 . By comparing the present electrical characteristics with the previous electrical characteristics, the statuses of all interchangeable battery modules  130  can be analyzed. Since the process of comparing the electrical characteristics is performed in a charging station, the environment of perfbrming the comparing process is more stable than in the electric vehicle. In other word, the data of the comparing process obtained in the charging station is more reliable and accurate. In accordance with the present invention, the battery pack provider can check the statuses of all interchangeable battery modules  130  in the battery management apparatus  100  whenever the charging operation is performed. In case that the interchangeable battery module  130  is seriously degraded to cause the mileage reduction, the interchangeable battery module  130  is replaced with a new one. Consequently, the battery pack provider can provide good leasing service. 
         [0025]    From the above descriptions, the present invention provides a battery management apparatus. A memory circuit is independently included in a battery management unit of an interchangeable battery module. The memory circuit is only accessible and powered by a battery pack management unit. In case that the interchangeable battery module has a fault event, the battery operation data stored in the memory circuit will not be adversely affected by the generated surge current. Even if one of the interchangeable battery modules has a malfunction, the battery pack provider can operate the battery pack management unit to read the battery operation data from the memory circuit through a memory I/O connector. According to the battery operation data, the causes of the fault event of the interchangeable battery module can be realized. Moreover, while the battery management apparatus is being charged, the state of health can be calculated according to the result of comparing the present electrical characteristics with the previous electrical characteristics. In comparison with the conventional technology, it is not necessary to download associated data from the battery pack management unit or the electronic control unit. Since the testing process is simplified, the battery management apparatus is industrially valuable and patentable according to the law. 
         [0026]    While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.