Patent Publication Number: US-2020282837-A1

Title: Railway vehicle equipped with an electrical storage body

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to French Patent Application No. FR 19 02289 filed on Mar. 6, 2019, the disclosure of which including the specification, the drawings, and the claims is hereby incorporated by reference in its entirety. 
     FIELD OF THE INVENTION 
     This invention concerns a railway vehicle of the type including a power supply device, an electrical traction motor, first auxiliary electrical equipment, and a connector connecting to an electrical power source external to the vehicle, wherein the power supply device comprises: an electrical converter suited to supply the electrical traction engine with high-voltage current, wherein the electrical converter is connected to the connector; a first medium-voltage electricity network to which the first auxiliary electrical equipment is connected, and a first electrical storage element connected to the first medium-voltage electricity network so as to supply electricity to or draw electricity from the first network. 
     BACKGROUND OF THE INVENTION 
     It is known to equip railway vehicles, in particular trains, with internal power storage elements. A vehicle as described above is described, for example, in document WO2014008114. The auxiliary equipment may thus be supplied by the internal elements or the external source, separately or simultaneously. 
     Auxiliary functions such as air conditioning of passenger carriages require significant electrical power. Supplying them via internal storage elements involves constraints and high costs for the vehicle&#39;s electrical power supply. 
     SUMMARY OF THE INVENTION 
     This invention seeks to solve this problem. To this end, the object of the invention is a railway vehicle as described above, wherein the electrical converter is connected to the first medium-voltage electricity network so as to supply the first network with electricity. 
     According to other advantageous aspects of the invention, the railway vehicle includes one or more of the following features, alone or in any combination technically possible:
         the power supply device comprises a first reversible charger interposed between the first electrical storage element and the first medium-voltage electricity network, wherein the first charger is suited to transfer electricity to one or the other of the first element and the first network;   the first power storage element comprises at least one lithium ion battery;   the railway vehicle further comprises second auxiliary equipment, and wherein the power supply device further comprises: a second low-voltage electricity network to which the second equipment is connected; and a second electrical storage element connected to the second low-voltage electricity network so as to supply electricity to or draw electricity from the second network; wherein the second storage element is also connected to the first medium-voltage electricity network so as to draw electricity from the first network;   the power supply device comprises a second charger interposed between the first medium-voltage electricity network and the second storage element so as to supply the second element with electricity from the first network, wherein the second charger is also connected to the second low-voltage electricity network so as to supply the second network with electricity without passing through the second storage element;   the second power storage element comprises at least one lithium ion battery.       

     The invention further concerns a method for operating a railway vehicle as described above. 
     According to a first aspect of the invention, the method is as follows: the electrical converter draws electricity from an electrical power source external to the vehicle via the connector, and supplies the first medium-voltage electricity network with electricity, and the first electrical storage element draws electricity from the first network. 
     According to second first aspect of the invention, the method is as follows: the electrical converter draws electricity from an electrical power source external to the vehicle via the connector, and supplies the electrical traction engine with electricity, and the first electrical storage element supplies the first medium-voltage electricity network with electricity. 
     According to a third aspect of the invention, the method is as follows: the first electrical storage element supplies the first medium-voltage electricity network with electricity, and the second electrical storage element draws electricity from the first network. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be better understood based on the following description, which is provided by way of example only and without limitation, and by reference to the drawings, which show: 
         FIG. 1  is a schematic view of a railway vehicle according to one embodiment of the invention, and 
         FIG. 2  is a schematic view of elements of the railway vehicle of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is a schematic representation of a railway vehicle  10  according to one embodiment of the invention. The railway vehicle  10 , e.g. a train, includes a motor  12  coupled to one or more carriages  14 , intended, in particular, for use by passengers. 
     The railway vehicle  10  includes at least one electrical traction engine  15  equipping the motor. The engine  15  is intended, in particular, to operate under high voltage, in particular greater than 700 V. 
     Additionally, the railway vehicle  10  includes first auxiliary electrical equipment  16 ,  17  intended to operate on a 400 V medium-voltage network. The first electrical auxiliary equipment comprises, e.g., one or more compressors  16  intended to inflate a pneumatic circuit of the vehicle  10 , air conditioning devices  17  for the carriages  14 , or thermal equipment such as a cold room for preserving foodstuffs. 
     Additionally, the railway vehicle  10  includes second auxiliary electrical equipment  18  intended to operate on a 110V low-voltage network. The second auxiliary electrical equipment  18  comprises, e.g., lighting and/or ventilation devices for the carriages  14 , or refrigerators. 
     The railway vehicle  10  additionally includes a power supply device  20  connected to the auxiliary electrical equipment  16 ,  17 ,  18 . The device  20  is suited to cooperate with an electrical power source external to the vehicle. In the embodiment shown, the railway vehicle  10  includes a pantograph  22  suited to supply the device  20  with electricity from a catenary (not shown). 
     The railway vehicle  10  further includes an electronic control module  24  suited to control the device  20 . 
       FIG. 2  is a schematic representation of several elements of the railway vehicle  10 , in particular the power supply device  20 . 
     In particular, the device  20  includes an inverter-type electrical converter  26 , a first input  28  of which is connected to the pantograph  22 . The converter  26  is suited to supply the engine  15  with high-voltage current, in particular greater than 700 V, via a first output  27 . 
     The device  20  also includes a first electrical storage element  30 . Preferably, the first element  30  is a battery, and more preferably comprises at least one lithium ion battery. Preferably, the first element  30  has a large capacity, on the order of 200 kWh. 
     Indeed, the lithium ion batteries allow for significant capacities at limited volumes. They also offer a longer useful life than other technologies, such as NiCad or lead gel. 
     Preferably, the element  30  is intended to store energy for non-safety-related comfort devices such as an air-conditioning system. 
     The device  20  additionally includes a first medium-voltage electricity network  34  to which the first auxiliary electrical equipment  16 ,  17  is connected. The electrical converter  26  is suited to supply the first network  34  with medium-voltage current via a second output  36 . 
     Additionally, the device  20  includes a first reversible charger  38 . A first  40  and a second reversible connection  42  electrically connect the first charger  38  to the first storage element  30  and the first network  34 , respectively. The first charger  38  is thus suited to transfer electricity reversibly between the first storage element  30  and the first network  34 . 
     The device  20  additionally includes a second, low-voltage electricity network  44  to which the second auxiliary electrical equipment  18  is connected. 
     The device  20  additionally includes a second electrical storage element  46 , comprising an output  47  connected to the second electricity network  44  so as to supply the network with electricity. Preferably, the second element  46  is a battery, and more preferably comprises at least one lithium ion battery. 
     Preferably, the element  46  is intended to store energy for safety-relevant devices, such as emergency lighting and/or radio that may be required by applicable regulations. 
     Additionally, the device  20  includes a second charger  48 . One input  50  of the second charger  48  is connected to the first medium-voltage electricity network  34 . A first  52  and a second output  54  of the second charger  48  are respectively connected to the second electrical storage element  46  and the second low-voltage electricity network  44 . 
     The electronic control module  24 , which is arranged, e.g., in a steering cabin of the engine  12 , is electronically connected to at least some of the aforementioned elements of the device  20 , as will be discussed below. Preferably, the electronic module  24  is connected to an on-train GSM network that allows it to receive up-to-date information on the rate for the electricity available via the catenary. 
     Now, methods for operating the railway vehicle  10  will be described. The electronic control module  24  is equipped, in particular, with programs suited to execute these methods. 
     First, we will consider a first method, referred to as ‘normal operation’. This method is executed, in particular, when the information received by the electronic module  24  indicate a cost for the electricity available via the catenary that is below a predetermined threshold. 
     In the first method, the electrical converter  26  is supplied by the catenary via the pantograph  22  and the first input  28 . The electrical converter  26  supplies the first medium-voltage electricity network  34  and the first auxiliary electrical equipment  16 ,  17 . The first network  34  also supplies the second low-voltage electricity network  44  via the second charger  48  and the second output  54 . 
     Furthermore, when the first  30  and/or second electrical storage element  46  are not completely charged, the first  40  and second reversible connections  42  of the first charger  38  and/or the first output  52  of the second charger  48  are configured to supply electricity from the first network  34  to the first  30  and/or second element  46 . 
     Now, we will consider a second method, referred to as ‘climate control emergency operation’. This second method is executed, in particular, when the vehicle  10  is immobilised on a section of a railway not equipped with a catenary or is immobilised following a failure of the catenary, in particularly in a hot, sunny environment. 
     In the second method, the reversible charger  38  is supplied by the first electrical storage element  30  via the connection  40 . The electrical charger  38  supplies the first medium-voltage network  34  and the first auxiliary electrical equipment  16 ,  17 , in particular the air-conditioning devices  17  of the carriages  14 . 
     In fact, the power supply for air conditioning requires a significant amount of power, which the reversible charger  38  is capable of providing. 
     Furthermore, in the aforementioned second method, the second electricity network  44  is supplied by the second storage element  46 . As needed, the second network  44  may also be partially supplied by the first network  34  via the second charger  48  and its second output  54 . 
     Now, a third method, known as ‘energy smoothing’, will be considered. The third method is executed, in particular, when the information received by the electronic module  24  indicates that the mains electricity available via the catenary is billed at peak rates. 
     In the third method, the electrical converter  26  is supplied by the catenary via the pantograph  22 , and supplies, e.g., the engine  15 . Additionally, the first  40  and second reversible connection  42  of the first charger  38  are configured such that the first element  30  supplies power to the first medium-voltage electricity network  34  and the first auxiliary electrical equipment  16 ,  17 . Thus, the electricity drawn by the pantograph  22  is primarily dedicated to the engine  15  in order to reduce the external power consumption of the vehicle  10 . 
     Preferably, the electronic module  24  controls the output  36  of the converter  26  such that the first network  34  draws the electricity primarily from the first element  30 , and, from the converter  26  on a non-priority basis as needed. 
     The first network  34  also supplies the second low-voltage electricity network  44  via the second charger  48  and the second output  54 . 
     The element  30  is then recharged when the electricity is no longer at peak rates. 
     A fourth method, referred to as ‘safety battery (element  46 ) recharging’ outside of recharging areas. This fourth method is executed, in particular, when the vehicle  10  is stationary, in particular at a location without a catenary. 
     In the fourth method, the engine  15  is stopped, and the electrical converter  26  is not supplied with power. The first  40  and second reversible connections  42  of the first charger  38  are configured such that the first element  30  supplies power to the first medium-voltage electricity network  34 . 
     In a first variant of the fourth method, when the second electrical storage element  46  is not fully charged, the first output  52  of the second charger  48  is configured so as to supply electricity from the first network  34  to the second element  46 . This method avoids providing the second element  46  with a recharging station specifically for stationary operation. 
     In a second variant of the fourth method, the first network  34  supplies some of the first auxiliary electrical equipment  16 ,  17 , e.g. a cold room for foodstuffs. The first network  34  may also supply the second network  44  and certain items of second auxiliary electrical equipment  18 , e.g. refrigerators, via the second charger  48 . This method allows for perishable foodstuffs to be preserved when the vehicle  10  is stationary, in particular in countries in which the element  22  is not permitted to be connected at night. 
     The aforementioned methods  1 - 4  may be executed successively by a single vehicle. 
     Thus, the railway vehicle according to the invention is more independent when no external power source is available. The railway vehicle also allows for a reduction in operating costs by storing electricity and restoring it based on real-time changes in rates.