Patent Publication Number: US-2012025763-A1

Title: Charging system of mobile vehicle and method for operating the same

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a charging system of a mobile vehicle and a method for operating the same, and more particularly to a charging system of a mobile vehicle, which installing a DC power conversion apparatus, and a method for operating the same. 
     2. Description of Prior Art 
     For today&#39;s technologies of driving mobile vehicles, that will be developed toward the trend of pollution-free and high-efficiency purposes. The battery is usually used to store the desired energy for the electric vehicles. In particular, the various generated energies, such as coal-fire energy, hydraulic energy, wind energy, thermal energy, solar energy, and nuclear energy, have to be converted into the electrical energy so that the electrical energy can be stored in the battery. However, the major issues of security, efficiency, and convenience have to be concerned during the energy conversion process. 
     Reference is made to  FIG. 1  which is a block diagram of a prior art charging system of a mobile vehicle. The charging system of the mobile vehicle (not shown) mainly includes a charging apparatus  10 A and a rechargeable battery  20 A. The mobile vehicle can be an electric vehicle, and the rechargeable battery  20 A is a rechargeable battery for electric vehicles. 
     The charging apparatus  10 A includes an electromagnetic interference (EMI) filter  102 A, a power factor corrector  104 A, and a non-isolated DC/DC converter  106 A. 
     The EMI filter  102 A of the charging apparatus  10 A is electrically connected to an external AC source Vs to eliminate the noise in the AC source Vs, thus preventing the conductive electromagnetic interference. The power factor corrector  104 A is electrically connected to the EMI filter  102 A to improve the power factor of the converted DC source. The non-isolated DC/DC converter  106 A is electrically connected to the power factor corrector  104 A to provide required voltage levels. In particular, the non-isolated DC/DC converter  106 A can be a buck converter or a DC transformer. 
     In actual application, the charging apparatus  10 A is a charging station for electric vehicles. 
     The charging apparatus  10 A can provide a high DC voltage Vo that outputs a fixed power. The charging apparatus  10 A typically outputs a 500-volt DC voltage that provides a 50-Kw or 30-kW power. If the power of the rechargeable battery  20 A is insufficient, the rechargeable battery  20 A is charged by directly connecting the charging apparatus  10 A to the rechargeable battery  20 A. In this charging system, however, the required charging current can not be provided to the rechargeable battery  20 A because operating conditions (such as the capacity, voltage, or temperature) of the rechargeable battery are not detected. Thus, the lifetime of the rechargeable battery  20 A would reduce. Furthermore, the charging reliability of the rechargeable battery  20 A would reduce because this charging system can not provide an adaptive charging manner for the rechargeable battery  20 A. In addition, the prior art charging system of the mobile vehicle usually uses mechanical-type relay for protecting the rechargeable battery  20 A. That is, the mechanical-type relay could provide a trip protection for the rechargeable battery  20 A during the charging process when the charging system has an abnormal operation. However, the response time of the mechanical-type relay is usually slow. Hence, the time of receiving an external trip signal and accomplishing the trip operation through the mechanical-type relay is usually long enough to damage the rechargeable battery  20 A when the abnormal operation occurs. 
     Accordingly, it is desirable to provide a charging system of a mobile vehicle and a method for operating the same that provide a charging protection and an adaptive charging manner for the rechargeable battery according to operating conditions of the rechargeable battery, thus increasing charging reliability, security, and speed. 
     SUMMARY OF THE INVENTION 
     In order to solve the above-mentioned problems, a charging system of a mobile vehicle is disclosed. The charging system of the mobile vehicle receives and converts an external AC source into a DC source for charging a rechargeable battery of the mobile vehicle. The charging system includes a charging apparatus and a mobile vehicle. 
     The charging apparatus includes an EMI filter and a power factor corrector. The EMI filter receives the external AC source. The power factor corrector is electrically connected to the EMI filter to output a high DC voltage. 
     The charging apparatus further includes a DC power conversion apparatus installed in the mobile vehicle and a vehicle controller installed in the mobile vehicle. The DC power conversion apparatus is installed in the mobile vehicle and is electrically connected to the charging apparatus to receive the high DC voltage and converts a voltage level of the high DC voltage into a required voltage level for the rechargeable battery. The vehicle controller is installed in the mobile vehicle and is electrically connected to the DC power conversion apparatus to control the DC power conversion apparatus to provide the required charging current for the rechargeable battery. 
     Therefore, the DC power conversion apparatus is installed in the mobile vehicle to provide charging protection for the rechargeable battery, and an adaptive charging manner is provided according to operating conditions of the rechargeable battery, thus increasing charging reliability, security, and speed. 
     In order to solve the above-mentioned problems, a charging method for a charging system of a mobile vehicle, the charging system receives and converts an external AC source into a DC source for charging a rechargeable battery of a mobile vehicle. The steps of the charging method as follows: First, a high DC voltage is provided through a charging apparatus. Afterward, the high DC voltage is received and a voltage level of the high DC voltage is converted into a required voltage level for the rechargeable battery through a DC power conversion apparatus. Finally, the required charging current for the rechargeable battery is provided according to the DC power conversion apparatus controlled by a vehicle controller. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. Other advantages and features of the invention will be apparent from the following description, drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWING 
       The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, may be best understood by reference to the following detailed description of the invention, which describes an exemplary embodiment of the invention, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a block diagram of a prior art charging system of a mobile vehicle; 
         FIG. 2  is a block diagram of a charging system of a mobile vehicle according to a first embodiment of the present invention; 
         FIG. 3  is a block diagram of a charging system of a mobile vehicle according to a second embodiment of the present invention; 
         FIG. 4  is a block diagram of a charging system of a mobile vehicle according to a third embodiment; 
         FIG. 5  is a block diagram of a charging system of a mobile vehicle according to a fourth embodiment; 
         FIG. 6  is a block diagram of a charging system of a mobile vehicle according to a fifth embodiment; and 
         FIG. 7  is a flowchart of a charging method for a charging system of a mobile vehicle. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made to the drawing figures to describe the present invention in detail. 
     Reference is made to  FIG. 2  which is a block diagram of a charging system of a mobile vehicle according to a first embodiment of the present invention. The charging system of the mobile vehicle receives and converts an external AC source into a DC source for charging a rechargeable battery of the mobile vehicle. The charging system of the mobile vehicle includes a charging apparatus  10  and a mobile vehicle  20 . In particular, the mobile vehicle  20  can be an electric vehicle. 
     The charging apparatus  10  mainly includes an EMI filter  102  and a power factor corrector  104 . The EMI filter  102  receives the external AC source Vs to eliminate the noise in the AC source Vs, thus preventing the conductive electromagnetic interference. The power factor corrector  104  is electrically connected to the EMI filter  102  to output a high DC voltage Vo. 
     The mobile vehicle  20  mainly includes a DC power conversion apparatus  202 , a rechargeable battery  204 , and a vehicle controller  206 . In this embodiment, the DC power conversion apparatus  202  is a non-isolated DC/DC converter  202 , and the non-isolated DC/DC converter  202  can be a buck converter or a DC transformer. The DC power conversion apparatus  202  is electrically connected to the charging apparatus  10  to receive the high DC voltage Vo and converts a voltage level of the high DC voltage Vo into a required voltage level for the rechargeable battery  204 . The rechargeable battery  204  is electrically connected to the DC power conversion apparatus  202 . In particular, the rechargeable battery  204  is a rechargeable battery for electric vehicles. The vehicle controller  206  is electrically connected to the DC power conversion apparatus  202  and the rechargeable battery  204  to control the DC power conversion apparatus  202  to provide the required charging current for the rechargeable battery  204 . Compared with the prior art, the non-isolated DC/DC converter  202  is changed from the charging apparatus  10  to the mobile vehicle  20 . 
     In actual application, the charging apparatus  10  is a charging station for electric vehicles. The charging apparatus  10  can provide the high DC voltage Vo that outputs a fixed power. The charging apparatus  10  typically outputs a 500-volt DC voltage that provides a 50-kW or 30-kW power. If the power of the rechargeable battery  204  is insufficient, the rechargeable battery  204  is charged by connecting the charging apparatus  10  to the DC power conversion apparatus  202  and then connecting the DC power conversion apparatus  202  to the rechargeable battery  204 . Hence, the vehicle controller  206  controls the DC power conversion apparatus  202  to provide the required charging current for the rechargeable battery  204  according to the capacity of the rechargeable battery  204 . Simultaneously, the corresponding charging time can be calculated. For example, if the rechargeable battery  204  is a high-capacity rechargeable battery, the vehicle controller  206  controls the DC power conversion apparatus  202  to provide a higher output charging current to the rechargeable battery  204 . Whereas, if the rechargeable battery  204  is a low-capacity rechargeable battery, the vehicle controller  206  controls the DC power conversion apparatus  202  to provide a lower outputted charging current to the rechargeable battery  204 . In addition, the vehicle controller  206  controls the DC power conversion apparatus  202  to provide the required charging current for the rechargeable battery  204  according to the voltage of the rechargeable battery  204 . Simultaneously, the corresponding charging time can be calculated. When the rechargeable battery  204  is charged to the desirable voltage, the vehicle controller  206  controls the DC power conversion apparatus  202  to reduce the required charging current for the rechargeable battery  204 . For example, if the rechargeable battery  204  is a high-capacity rechargeable battery (which needs a higher voltage), the vehicle controller  206  controls the DC power conversion apparatus  202  to provide a higher output charging current to the rechargeable battery  204 . However, if the rechargeable battery  204  is a low-capacity rechargeable battery (which needs a lower voltage), the vehicle controller  206  controls the DC power conversion apparatus  202  to provide a lower outputted charging current to the rechargeable battery  204 . In addition, the vehicle controller  206  controls the DC power conversion apparatus  202  to provide the required charging current for the rechargeable battery  204  according to the capacity and temperature of the rechargeable battery  204 . Simultaneously, the corresponding charging time can be calculated. For example, if the rechargeable battery  204  is operated in a higher-temperature condition, the vehicle controller  206  controls the DC power conversion apparatus  202  to provide a lower outputted charging current to the rechargeable battery  204 . However, if the rechargeable battery  204  is operated in a lower-temperature condition, the vehicle controller  206  controls the DC power conversion apparatus  202  to provide a higher output charging current to the rechargeable battery  204 . 
     Reference is made to  FIG. 3  which is a block diagram of a charging system of a mobile vehicle according to a second embodiment of the present invention. In this embodiment, the operation manners of the charging apparatus  10  and the mobile vehicle  20  are similar to those of the first embodiment. The major difference, however, is that the charging apparatus  10  further includes an isolated DC/DC converter  106 . The isolated DC/DC converter  106  is electrically connected to the power factor corrector  104  to output the high DC voltage Vo. 
     Reference is made to  FIG. 4  which is a block diagram of a charging system of a mobile vehicle according to a third embodiment of the present invention. In this embodiment, the operation manners of the charging apparatus  10  and the mobile vehicle  20  are similar to those of the first embodiment. The major difference, however, is that the DC power conversion apparatus  202  of the mobile vehicle  20  further includes an isolated DC/DC converter  2022 . The isolated DC/DC converter  2022  is electrically connected to the non-isolated DC/DC converter  2024  to receive the high DC voltage Vo outputted from the charging apparatus  10 . 
     Reference is made to  FIG. 5  which is a block diagram of a charging system of a mobile vehicle according to a fourth embodiment of the present invention. In this embodiment, the operation manners of the charging apparatus  10  and the mobile vehicle  20  are similar to those of the first embodiment. The major difference, however, is that the charging apparatus  10  further includes an isolated DC/DC converter  106  and a non-isolated DC/DC converter  108 . The isolated DC/DC converter  106  is electrically connected to the power factor corrector  104 , and the non-isolated DC/DC converter  108  is electrically connected to the isolated DC/DC converter  106  to output the high DC voltage Vo. In particular, the non-isolated DC/DC converter  108  can be a buck converter or a DC transformer. 
     Reference is made to  FIG. 6  which is a block diagram of a charging system of a mobile vehicle according to a fifth embodiment of the present invention. In this embodiment, the operation manners of the charging apparatus  10  and the mobile vehicle  20  are similar to those of the first embodiment. The major difference, however, is that the charging apparatus  10  further includes a non-isolated DC/DC converter  108 . The non-isolated DC/DC converter  108  is electrically connected to the power factor corrector  104  to output the high DC voltage Vo. 
     Reference is made to  FIG. 7  which is a flowchart of a charging method for a charging system of a mobile vehicle. Although the charging apparatus and the DC power conversion apparatus have different embodiments, the charging manner of the mobile vehicle is identical. The charging method is provided to receive and convert an external AC source into a DC source, and then the DC source is used to charge the mobile vehicle. The steps of the charging method as follows: First, a high DC voltage is provided through a charging apparatus (S 100 ). In particular, the charging apparatus includes an EMI filter and a power factor corrector. The power factor corrector is electrically connected to the EMI filter to output the high DC voltage. The charging apparatus includes an EMI filter, a power factor corrector, and an isolated DC/DC converter. The power factor corrector is electrically connected to the EMI filter, and the isolated DC/DC converter is electrically connected to the power factor corrector to output the high DC voltage. Furthermore, the charging apparatus includes an EMI filter, a power factor corrector, and a non-isolated DC/DC converter. The power factor corrector is electrically connected to the EMI filter, and the non-isolated DC/DC converter is electrically connected to the power factor corrector to output the high DC voltage. Furthermore, the charging apparatus includes an EMI filter, a power factor corrector, an isolated DC/DC converter, and a non-isolated DC/DC converter. The power factor corrector is electrically connected to the EMI filter, the isolated DC/DC converter is electrically connected to the power factor corrector, and the non-isolated DC/DC converter is electrically connected to the isolated DC/DC converter to output the high DC voltage. 
     Afterward, the high DC voltage is received and a voltage level of the high DC voltage is converted into a required voltage level for the rechargeable battery through a DC power conversion apparatus (S 200 ). In particular, the DC power conversion apparatus is a non-isolated DC/DC converter to receive the high DC voltage outputted from the charging apparatus. Furthermore, the DC power conversion apparatus includes an isolated DC/DC converter and a non-isolated DC/DC converter. The isolated DC/DC converter is electrically connected to the non-isolated DC/DC converter to receive the high DC voltage outputted from the charging apparatus. 
     Finally, the required charging current for the rechargeable battery is provided according to the DC power conversion apparatus controlled by a vehicle controller (S 300 ). If the power of the vehicle rechargeable battery is insufficient, the rechargeable battery is charged by connecting the charging apparatus to the DC power conversion apparatus and then connecting the DC power conversion apparatus to the rechargeable battery. Hence, the vehicle controller controls the DC power conversion apparatus to provide the required charging current for the rechargeable battery according to the capacity of the rechargeable battery. Simultaneously, the corresponding charging time can be calculated. For example, if the rechargeable battery is a high-capacity rechargeable battery, the vehicle controller controls the DC power conversion apparatus to provide a higher output charging current to the rechargeable battery. However, if the rechargeable battery is a low-capacity rechargeable battery, the vehicle controller controls the DC power conversion apparatus to provide a lower outputted charging current to the rechargeable battery. In addition, the vehicle controller controls the DC power conversion apparatus to provide the required charging current for the rechargeable battery according to the voltage of the rechargeable battery. Simultaneously, the corresponding charging time can be calculated. When the rechargeable battery is charged to the desirable voltage, the vehicle controller controls the DC power conversion apparatus to reduce the required charging current for the rechargeable battery. For example, if the rechargeable battery is a high-capacity rechargeable battery (which needs a higher voltage), the vehicle controller controls the DC power conversion apparatus to provide a higher output charging current to the rechargeable battery. However, if the rechargeable battery is a low-capacity rechargeable battery (which needs a lower voltage), the vehicle controller controls the DC power conversion apparatus to provide a lower outputted charging current to the rechargeable battery. In addition, the vehicle controller controls the DC power conversion apparatus to provide the required charging current for the rechargeable battery according to the capacity and temperature of the rechargeable battery. Simultaneously, the corresponding charging time can be calculated. For example, if the rechargeable battery is operated in a higher-temperature condition, the vehicle controller controls the DC power conversion apparatus to provide a lower outputted charging current to the rechargeable battery. Whereas, if the rechargeable battery is operated in a lower-temperature condition, the vehicle controller controls the DC power conversion apparatus to provide a higher output charging current to the rechargeable battery. 
     In conclusion, the present invention has following advantages: 
     1. The DC power conversion apparatus, which is installed in the mobile vehicle, is used to provide charging protection; and 
     2. An adaptive charging manner is provided according to operating conditions of the rechargeable battery, thus increasing charging reliability, security, and speed. 
     Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.