Abstract:
This installation includes, on-board the vehicle ( 12 ) equipped with a battery ( 30 ), an on-board device ( 20 ), electrically connected to the battery ( 30 ) and provided with a plurality of electric contacts, and on the ground, a ground device ( 40 ), combined with the on-board device ( 20 ), connected to an electric power source ( 50 ) and including a plurality of electric contacts, each electric contact of the ground device ( 40 ) being able to be put into contact with a corresponding contact of the on-board device ( 20 ) and the installation being able to apply, safely, an electric recharging power issued by the electric power source ( 50 ) to the battery ( 30 ). This installation is characterized in that the plurality of electric contacts of the on-board device ( 20 ) and of the ground device ( 40 ) exclusively includes two electric contacts, i.e. a phase contact ( 21; 41 ) and neutral contact ( 22; 42 ).

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to installations for recharging by conduction energy storage means loaded on board electric or hybrid vehicles, notably buses. 
       BACKGROUND OF THE INVENTION 
       [0002]    A tyre vehicle, like a bus, is specific in the sense that its chassis (and its body by electric continuity) is normally electrically insulated from the ground, because of its tires and this as compared with a railway vehicle, a tramway for example. 
         [0003]    Recharging by conduction has many advantages as notably compared with the recharging by induction. It allows faster recharging, with a higher yield, and a less complex infrastructure and having a lower cost. 
         [0004]    For recharging by conduction a bus, putting into contact an on-board device connected to energy storage means is presently contemplated with a ground device connected to an electric power source so as to establish four electric connections simultaneously:
       A first neutral connection and a second phase connection for transferring electric power from the ground to on-board (or alternatively a first negative connection and a positive second connection);   A third ground connection in order to put the chassis of the bus to the ground potential and thereby ensure the safety of the persons around the bus during the power transfer; and,   A fourth communication connection I allowing exchange of data according to a predefined protocol between on-board and the ground, for example the current charge condition of the energy storage means in order to adapt the electric parameters of the electric power to be provided, or for triggering the application of the recharging current when certain constraints are verified, such as the immobilization of the bus, certified grounding, etc.       
 
         [0008]    Such an installation may assume the form of a male connector as an on-board device and a female connector as a ground device; of a pantograph as an on-board device and of an areal pole for the ground device; or further a current collector as an on-board device and a pad implanted in the track as a ground device. 
         [0009]    Such an installation requiring the establishment of four connections by electrically connecting each pair of contacts of a set of four pairs, a pair including a contact on the on-board device and a corresponding contact on the ground device, remains complex to manufacture and to maintain in an operating condition. 
       SUMMARY OF THE INVENTION 
       [0010]    There is a need for simplification while the guaranteeing the safety of persons during the recharging to which the present invention provides an answer. 
         [0011]    Thus, the object of the invention is an installation for recharging by conduction including, on-board a vehicle equipped with an electric energy storage means, an on-board device, electrically connected to the electric energy storage means and provided with a plurality of electric contacts, and, on the ground, a ground device, combined with the on-board device, connected to an electric power source and including a plurality of electric contacts, each electric contact of the ground device being able to be put into contact with a corresponding contact of the on-board device and the installation is able to apply, safely, an electric recharging power delivered by the electric power source to the electric energy storage, characterized in that said plurality of electric contacts of the on-board device and of the ground device exclusively has two electric contacts, i.e. a phase contact and a neutral contact. 
         [0012]    According to particular embodiments, the installation includes one or several of the following features, taken individually or according to all the technically possible combinations:
       the neutral contact of the on-board device is electrically connected to a chassis of the vehicle and the neutral contact of the ground device is electrically connected to a ground connection.   the installation includes a means for controlling the ground connection able to check, at each instant of application of an electric recharging power to the electric energy storage means that the neutral contact of the on-board device is in electric contact with the neutral contact of the ground device and that the phase contact of the on-board device is in electrical contact with the phase contact of the ground device.   the neutral contact of the on-board device includes a first electrode and a second electrode, and the phase contact of the on-board device includes a first electrode and a second electrode, the pair of first electrodes forming the input terminals of a first circuit for applying an electric recharging power to energy storage and the pair of first electrodes forming the input terminals of a second circuit for establishing a ground connection and for controlling the latter during the recharging, the second circuit belonging to the means for controlling the ground connection.   the control means includes a transmitter, fitting out a device from among the ground device and the on-board device, able to apply an electric test signal to an electric circuit including the pair of phase contacts and the pair of neutral contacts and a receiver, fitting out the other device, able to receive the electric test signal exclusively when there is an effective contact between the pair of phase contacts and an effective contact between the pair of neutral contact, and able to transmit a reception signal of the electric test signal towards the transmitter, the reception signal being preferably transmitted by means of a wireless link established between a wireless communication module of the on-board device and a wireless communication module of the ground device.   the ground device is able to disconnect from the electric power source when the electric test signal transmitted by the transmitter is not received by the receiver or when the reception signal of the test signal transmitted by the receiver is not received by the transmitter or is indicative of a breakage of an electric connectivity between the pairs of neutral contacts and the pair of phase contacts.   the on-board device includes a link between the phase contact and the neutral contact consisting of a trap circuit in series with the primary of a transformer, to the secondary of which is connected the receiver, and in which the ground device includes a connection between the phase contact and the neutral contact consisting of a trap circuit in series with the primary of a transformer, to the secondary of which is connected the transmitter.   An installation dedicated to a vehicle of the bus type, the chassis of which is normally electrically insulated from the ground.   An installation wherein: the ground device includes a pad implanted in the roadway for circulation of the vehicle, so as to be flushed with the surface of said roadway, said pad bearing phase and neutral contacts of the ground device; and the on-board device includes at least one current collector, bearing the phase and neutral contacts of the on-board device, mounted so as to be movable relatively to the chassis of the vehicle and able to be displaced towards the pad so as to establish electric connectivity between the pairs of contacts.   the on-board device is mounted under a body of the vehicle, said vehicle having to be placed above the pad so as to allow establishment of an electric connectivity between the pairs of contacts of the ground and on-board devices, the pad being then located inside the ground imprint of the vehicle.       
 
         [0022]    The object of the invention is also a recharging method for recharging a vehicle by using the previous installation, characterized in that it includes the steps consisting of: stopping the vehicle in a predefined recharging position relatively to a recharging station; putting the pair of contacts of the on-board device in contact with the pair of contacts of the ground device; recharging by applying an electric power generated by the source to the energy storage means, via the ground device and the on-board device; controlling the grounding of a chassis of the vehicle at each instant of the recharging, any negative verification leading to interrupting the recharging. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    The invention and advantages thereof will be better understood upon reading the detailed description which follows of a particular embodiment of the invention, exclusively given as an illustrative and non-limiting example. This description is made with reference to the appended drawings wherein: 
           [0024]      FIG. 1  schematically illustrates the recharging installation according to the invention; 
           [0025]      FIG. 2  illustrates as blocks, the recharging method using the installation of  FIG. 1 ; and, 
           [0026]      FIG. 3  schematically illustrates an alternative of the recharging installation of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]      FIG. 1  illustrates an embodiment of a installation  10  for electric conduction recharging giving the possibility of applying, in safety, an electric power issued by a source  50  of a permanent recharging station  11 , to a means for storing electric energy  30  belonging to a power circuit  14  of a bus  12 . 
         [0028]    The bus  12  includes a control and monitoring device  16 . 
         [0029]    It includes a module for measuring insulation  15 , in order to make sure that the power circuit  14  is galvanically insulated from the chassis of the bus  12  at every instant. 
         [0030]    It also includes a radio communication module  17  able to establish a wireless communication link  99  with a radio communication module  57 , with which the source  50  is equipped. For example this is a wireless link applying a communication protocol compliant with the protocol known under the name of Bluetooth®. 
         [0031]    The installation  10  includes, loaded on-board the bus  12 , an on-board device  20 . 
         [0032]    As an input, the on-board device  20  exclusively includes two terminals, forming two contacts, respectively a phase contact  21  and a neutral contact  22 . Alternatively, these contacts are a negative contact at a negative voltage, and a positive contact at a positive voltage. 
         [0033]    At the output, the on-board device  20  is connected through first and second output terminals  23  and  24  to the terminals of the electric energy storage means  30 , for example consisting of a battery, but other technical solutions are known to one skilled in the art. 
         [0034]    The installation  10  includes at least one ground device  40 , being part of the recharging station  11 . Advantageously, the installation comprises two ground devices, the second device allowing a redundancy of the first device. 
         [0035]    As an input, the ground device  40  is connected through first and second input terminals  43  and  44  to the terminals of the source  50 . The source  50  is for example a sub-station for supplying power to an electric network. 
         [0036]    As an output, the ground device  40  exclusively includes two output terminals forming two contacts, the phase contact  41  and the neutral contact  42  respectively. 
         [0037]    In the embodiment shown here in detail, the contacts  41  and  42  of the ground device  40  are integrated into a pad  60 , implanted into the roadway  13  so as to have a greater surface flush with the surface of the roadway for circulation of the bus  12 . 
         [0038]    The on-board device  20  then includes a shoe  62 , also called a collector shoe or a collection system, mounted under the body of the bus  12  and able to be displaced vertically between an upper position away from the pad  60  and a low position in contact with the pad  60 . In the low position, the phase contact  21  of the on-board device  20  is in electric contact with the phase contact  41  of the ground device  40  and the neutral contact  22  of the on-board device  20  is in electric contact with the neutral contact  42  of the ground device  40 . 
         [0039]    The on-board device  20  includes a link between a phase mesh  25  which connects the phase contact  21  and the first output terminal  23 , and a neutral mesh  26  which connects the neutral contact  22  and the second output terminal  24 . 
         [0040]    This link includes a wave trap circuit  72 , including an inductor and a capacitor, in series with the primary coil of a transformer  82 . 
         [0041]    At the secondary of the transformer  82 , the on-board device  20  includes a receiver  92 . 
         [0042]    The trap circuit  72  is characterized by a tuning frequency f 0 . 
         [0043]    In proximity to the neutral contact  22 , the neutral mesh  26  is electrically connected to the chassis of the bus  12 . This is schematically illustrated in  FIG. 1  by the ground connection  29 . 
         [0044]    Between this connection and the output terminals  23 ,  24 , each mesh  25 ,  26  is equipped with a controlled contacter,  27  and  28 , respectively, able to switch from an open state to a closed state. 
         [0045]    The on-board device  20  includes a wireless communication module  64  with a short range for example of the RFID type, borne by the current collector  62  and connected to the receiver  92 . 
         [0046]    The ground device  40  includes a link between a phase mesh  45  which connects the phase contact  41  and the first input terminal  43  and a neutral mesh  46  which connects the neutral contact  42  and the second input terminal  44 . 
         [0047]    This connection includes a trap circuit  74 , including an inductor and a capacitor, in series with the primary coil of a transformer  84 . 
         [0048]    At the secondary of the transformer  84 , the ground device  40  includes a transmitter  94 . 
         [0049]    The trap circuit  74  is characterized by a tuning frequency which is selected so as to be substantially equal to the tuning frequency of the trap circuit  72 . 
         [0050]    In proximity to the neutral contact  42 , the neutral mesh  46  is electrically connected to a ground connection. This is schematically illustrated in  FIG. 1  by the ground connection  49 . 
         [0051]    Between the phase contact  41  and the output terminal  43 , the phase mesh  45  is equipped with a controlled switch  47 . Further, a safety contacter  48  is placed between the phase mesh and the neutral mesh. The contacter  48  is used for redundant safeguarding, and is only closed during an internal failure of the device  40 , or during a maintenance intervention. 
         [0052]    Finally, a switch  75  is placed in a bypass of the trap circuit  74 , between the transformer  84  and the phase mesh  45 . 
         [0053]    The ground device  40  includes a wireless communication module  66  with a short range, for example of the RFID type, able to exchange data with the conjugate module  64 . The module  66  is borne by the pad  60  and is connected to the transmitter  94 . 
         [0054]    The recharging method  100  applied for recharging the energy storage means  30  of the bus  12  by using the installation  10  will now be described with reference to  FIG. 2 . 
         [0055]    In self-containment (step  110 ), the power circuit  14  is galvanically insulated from the chassis of the bus  12 . In particular, the contacter  28  is open, so that the electric energy storage means  30  is insulated from the chassis. The insulation measurement device  15  checks at each instant that the chassis is actually insulated from the power circuit  14 . 
         [0056]    The wireless communication module  66  on the ground permanently transmits a localization signal. 
         [0057]    The transmitter  94  of the ground device  40  transmits (step  120 ) permanently a coded signal at the secondary of the transformer  84 . However, the primary of the transformer  84  being in an open circuit, no current circulates in the primary of the transformer  84 . 
         [0058]    When the driver wishes to recharge the bus  12  which he/she drives, he/she approaches a recharging station  11  and stops it (step  130 ) in a predefined recharging position, indicated by suitable markings on the ground. In this recharging position, the current collector  62  is vertically above the pad  60 . 
         [0059]    Upon stopping the bus, the monitoring-control device  16  of the bus  12  detects the presence of the pad  60  by receiving the localization signal transmitted by the module  66  and received by the corresponding module  64  loaded on-board the bus. The monitoring-control device  16  of the bus  12  immobilizes the bus. It initiates the recharging process by controlling the downward movement of the current collector  62  for applying it against the pad  60  (step  140 ). 
         [0060]    By doing this, the contact phase  21  of the on-board device  20  will come into electric contact with the phase contact  41  of the ground device  40  and the neutral contact  22  of the on-board device  20  will come into contact with the neutral contact  42  of the ground device  40 . 
         [0061]    Under these conditions, a closed circuit is established (step  150 ) including the primary of the transformer  84 , the neutral mesh  46  of the ground device  20 , the neutral mesh  26  of the on-board device  40 , the primary of the transformer  82 , the wave trap circuit  72 , the phase mesh  25  of the on-board device  20 , the phase mesh  45  of the ground device  40  and the closed contact  75 . 
         [0062]    In this way, the coded signal applied by the transmitter  94  to the secondary of the transformer  84  is transmitted through this closed circuit. It is transmitted as an electric test signal, which is an AC current at a frequency selected so as to correspond to the tuning frequency f 0  of the trap circuits  74  and  72 . 
         [0063]    This current crossing the primary of the transformer  84 , it may be detected at the secondary by the receiver  92 . 
         [0064]    Thus, the receiver  92  receives (step  160 ) the coded signal. The receiver  92  uses this coded signal for elaborating a reception message for the electric test signal. 
         [0065]    This message is then transmitted (step  170 ) from the on-board device  20  to the ground device  40  by means of the radioelectric link established between the wireless communication modules  64  and  66 . 
         [0066]    The receiver  66  receives (step  180 ) the reception message for the electric test signal. 
         [0067]    The reception by the ground of the reception message for the electric test signal indicates that the contact between the pairs of contacts of the installation is correctly established, in particular that the chassis of the bus  12  is at ground potential, the link  29  being in an electric continuity with the link  49 , via the neutral mesh  26  and the neutral mesh  46  connected together. 
         [0068]    At this stage, the optional insulation measurement carried out by the device for measuring the insulation of the bus is inhibited (step  190 ) by the monitoring-control device  16  of the bus  12 , the receiver  92  indicating that it receives the test signal. 
         [0069]    In the next step, the grounding of the phase mesh  45  of the ground device  40  is disconnected (step  200 ), since the phase contact  41  is physically inaccessible (located under the bus) and the chassis of the bus  12  being grounded. The switch  75  is therefore switched to the open position. 
         [0070]    Once the switch  75  is open, the test signal passes through the wave trap circuit  74 . 
         [0071]    The means for controlling the grounding, carried out in the present embodiment by transmitting a test signal through the ground, the reception of the test signal and the transmission of a reception message for the test signal by on-board, and finally the reception of the message of reception of the test signal by the ground, ensures permanent checking during the charging process. 
         [0072]    Any loss of grounding, whatever the cause, leads to interrupting the recharging. In the present embodiment, this requires immediate disconnection of the pad  60  of the source  50  by opening the contacter  47 , as well as by the momentary stopping of the transmission of the test signal by the transmitter  94 , causing on-board the opening of the contacts  27  and  28 , and the closing of the contacter  75 . 
         [0073]    It should be noted that the current carrying the coded signal is transmitted at the tuning frequency f 0  of the trap circuits  72  and  74 . Thus, the trap circuits prevent any circulation of low frequency current (in particular of the recharging current) between the phase mesh and the corresponding neutral mesh (the capacitor behaving as an open circuit at a low frequency), but on the other hand allows the flow of a current with a frequency close to the tuning frequency (in particular the current carrying the test signal). 
         [0074]    The contacter  47  is then closed (step  210 ) in order to establish an electric contact between the source  50  and the on-board device  20 , via the ground device  40 . 
         [0075]    Next, by the wireless communication link  99  between the monitoring-control device  16  of the bus  12  and the source  50 , the source  50  is informed (step  220 ) that a connection is established. 
         [0076]    The source  50  adapts characteristics of the recharging current to be generated and to apply to the terminals of the ground device  40 . 
         [0077]    Advantageously, a measurement of the insulation between the input terminals  43  and  44  of the ground device  40  is then carried out by the source  50 . This measurement is made at a low impedance, since the pad  60  on the ground has high leakage currents to the ground (a resistance from 10 to 1000 Ohms in the case of a pad wet by rain). 
         [0078]    Next, the source  50  informs (step  230 ) the monitoring-control device  16  of the bus, via the wireless communication link  99 , that recharging may begin. 
         [0079]    The monitoring-control device  16  of the bus  12  then switches (step  240 ) to closing the contacters  27  and  28  of the on-board device  20  in order to connect the latter to the terminals of the energy storage means  30 . 
         [0080]    The charging then begins (step  250 ). 
         [0081]    It is maintained until reception (step  260 ) by the driver of the bus of a request for interrupting the power supply. 
         [0082]    The source  50 , informed on the interruption of the power supply, stops applying an electric power between the input terminals of the ground device  40 . The contacters  27  and  28  are opened (step  270 ) and the ground device  40  switches to opening the contacter  47 , to closing the contacter for connecting to the ground  75 . 
         [0083]    The current collector  62  may then be actuated so as to be replaced in its upper position, before the bus leaves (step  280 ). 
         [0084]    An alternative embodiment is illustrated in  FIG. 3 . In this figure, an element identical with an element of  FIG. 1  is designated by the reference number used, in  FIG. 1 , for designating this identical element and an element similar to an element of  FIG. 1  is designated by the reference number used, in  FIG. 1 , for designating this similar element, increased by a hundred. 
         [0085]    In this alternative embodiment, the on-board device  120  of the installation  110  includes a first circuit for conveying the electric power towards the battery and a second circuit for establishing the connection for connecting to the ground and its control. The first and second circuits are independent of each other. This independence is required in order to avoid the effects of a potential difference related to the formation of an electric arc between pairs of contacts when the current collector is moved closer or away from the pad on the ground. 
         [0086]    Thus, the current collector  162  bears contacts which consist of two electrodes. 
         [0087]    More specifically, above the phase contact  41  of the pad on the ground  60  and coming into contact simultaneously with the latter, the phase contact of the current collector  162  consists of two electrodes  121  and  121 ′ distinct and electrically insulated from each other. 
         [0088]    Also, above the neutral contact  42  of the pad on the ground  60  and coming into contact simultaneously with the latter, the neutral contact of the current collector  162  consists of two electrodes  122  and  122 ′ distinct and electrically insulated from each other. 
         [0089]    Thus, the first circuit (electrode  121 , phase mesh  25 , contacter  27 , energy storage means, contacter  28 , neutral mesh  26  and electrode  122 ) is dedicated and suitable for the passing of a recharging current. 
         [0090]    The second circuit (electrode  121 ′, wave trap circuit  72 , primary of the transformer  82  and electrode  122 ′, as well as the connection  29  to the ground on the side of the electrode  122 ′) is dedicated and suitable for establishing the connection to the ground and to the circulation of the signal for checking grounding.