A main and auxiliary converter system suitable for inner heavy-duty electric locomotive operation in a network-free area

Abstract

This invention discloses a main and auxiliary converter system suitable for operation of double-unit electric locomotives in grid-free areas. It includes main and auxiliary converter units housed within a main and auxiliary converter cabinet. Each unit comprises a four-quadrant input component, a four-quadrant power module, traction and DC / DC power modules (i.e., a first power module and a second power module), a medium-voltage auxiliary power supply component, an auxiliary inverter module, and a charger power module. The four-quadrant input component is connected to the main transformer. The output of the four-quadrant input component is connected to the input of the four-quadrant power module, and the output of the four-quadrant power module is connected to the first power module, the second power module, the auxiliary inverter module, and the charger power module. The medium-voltage auxiliary power supply component and the four-quadrant power module are connected to the auxiliary inverter module. The auxiliary inverter module is connected to a cooling fan assembly. This invention solves the technical problems of existing technologies, such as the inability to operate in grid-free areas, the limited capacity of onboard energy storage devices, range anxiety in locomotives, and the impact of frequent energy replenishment on production efficiency.

Description

Technical Field

[0001] This invention relates to the field of electric locomotive technology, and in particular to a main and auxiliary converter system suitable for electric locomotives operating in grid-free areas with multiple units of internal coupling. Background Technology

[0002] Currently, railway locomotives have the following power supply methods: Electric locomotives are locomotives that obtain electrical energy from the power grid (overhead contact line) or power rails and then drive the vehicle through an electric motor. The electrical energy required for the operation of electric locomotives is provided by the power supply system of electrified railways. Diesel locomotives are powered by an internal combustion engine. The engine burns fuel, which drives the piston to rotate, causing the crankshaft to rotate, which in turn drives the generator. The generator produces three-phase alternating current, which is then converted into electricity to power the traction motor, propelling the locomotive forward. New energy locomotives are powered by onboard energy storage devices, such as power batteries or supercapacitors. The direct current output from these devices is converted into electricity to power the traction motor, propelling the locomotive forward. Hybrid locomotives utilize an onboard energy storage device and an internal combustion engine as their power sources. The internal combustion engine burns fuel, driving pistons to rotate the crankshaft, which in turn drives a generator. The generator produces three-phase AC power, which is then converted to power the traction motor, propelling the locomotive forward. The locomotive's electric drive system can also be powered by the onboard energy storage device, which, after conversion, powers the traction motor, further propelling the locomotive. Simultaneously, the generator can charge the onboard energy storage device. However, existing technologies have the following shortcomings: (1) Electric locomotives cannot operate in areas without grid access; (2) Internal combustion locomotives. Users will spend a lot of fuel purchase costs every year, resulting in high vehicle operating costs. Locomotives emit a lot of polluting gases during operation, and the internal combustion engine is very noisy, resulting in poor working environment for operators. Moreover, under the "dual carbon" target, this power supply method is obviously no longer in line with the long-term development needs of the industry. (3) New energy locomotives are limited by axle load, and the capacity of on-board energy storage devices is limited. Locomotives have range anxiety. When the on-board energy storage device runs out of power, it needs to be charged or swapped frequently. Frequent energy replenishment will affect production efficiency. Battery swapping will increase the procurement cost of power batteries and add expensive battery swapping equipment. (4) Hybrid locomotives still need to be equipped with internal combustion engines or range extenders. Internal combustion engines can increase the range of locomotives to some extent. However, vehicles need to be equipped with internal combustion engines, fuel tanks, and on-board energy storage devices. Furthermore, the use of internal combustion engines will still result in exhaust emissions, and the working environment for operators will be harsh. Summary of the Invention

[0003] This invention provides a main and auxiliary converter system suitable for the operation of electric locomotives in areas without grid connection, in order to overcome the above-mentioned technical problems.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: A main and auxiliary converter system suitable for the operation of electric locomotives in areas without grid grids, comprising a main and auxiliary converter unit installed in a main and auxiliary converter cabinet; wherein the main and auxiliary converter unit comprises a four-quadrant input component, a four-quadrant power module, a traction and DC / DC power module, a medium-voltage auxiliary power supply component, an auxiliary inverter module, and a charger power module; wherein the traction and DC / DC power module comprises a first power module and a second power module; The input terminal of the four-quadrant input component is connected to the main transformer; the output terminal of the four-quadrant input component is connected to the input terminal of the four-quadrant power module to realize AC power supply on / off control and current detection of the four-quadrant power module; the output terminal of the four-quadrant power module is connected to the first power module, the second power module, the auxiliary inverter module, and the charger power module respectively; the four-quadrant power module is used to convert the AC power output from the four-quadrant input component into high-voltage DC power; and the two ends of the medium-voltage auxiliary power supply component are respectively connected to one end of the four-quadrant power module and one end of the auxiliary inverter module; the other end of the auxiliary inverter module is connected to the cooling fan assembly; the medium-voltage auxiliary power supply component is used to cooperate with the auxiliary inverter module to realize power supply on / off control and overload protection; the cooling fan assembly is used to cool the modules in the main and auxiliary converter cabinets. The first power module and the second power module are respectively used to charge the preset first power battery and the second power battery by stepping down the high-voltage DC power output from the four-quadrant power module and charging the preset first power battery and the second power battery when there is a power grid; or to boost the DC power output from the first power battery and the second power battery through their DC / DC bridge arm and then convert the boosted DC power into AC power through their inverter bridge arm to power the preset first drive traction motor and the second drive traction motor when there is no power grid. A first DC / DC output component is provided between the first power module and the first power battery; a second DC / DC output component is provided between the second power module and the second power battery to realize the charging and discharging control of the first power battery and the second power battery, as well as battery voltage detection, battery charging current detection, battery discharging current detection, and high voltage indication of the power battery.

[0005] Furthermore, the four-quadrant input component includes a first charging contactor KM81, a first charging resistor R81, a first main contactor KM82, and an input current sensor SC81; one end of the first charging contactor KM81 is connected to the positive terminal interface of the secondary winding of the main transformer and one end of the first main contactor KM82; the other end of the first charging contactor KM81 is connected to one end of the first charging resistor R81; the other end of the first charging resistor R81 is connected to the other end of the first main contactor KM82; and one end of the input current sensor SC81 is connected to the negative terminal interface of the secondary winding of the main transformer.

[0006] Furthermore, the four-quadrant power module includes a first IGBT module VT31, a second IGBT module VT32, a third IGBT module VT33, a fourth IGBT module VT34, a first discharge resistor R31, a first supporting capacitor C31, and a first voltage sensor SV31; one end of the first IGBT module VT31 is connected to one end of the second IGBT module VT32, one end of the third IGBT module VT33, one end of the fourth IGBT module VT34, one end of the first discharge resistor R31, one end of the first supporting capacitor C31, and one end of the first voltage sensor SV31; the first I The other end of GBT module VT31 is connected to the other ends of the second IGBT module VT32, the third IGBT module VT33, the fourth IGBT module VT34, the first discharge resistor R31, the first support capacitor C31, and the first voltage sensor SV31; the other end of the first charging resistor R81 is connected to the connection node in the first IGBT module VT31 and the second IGBT module VT32; the other end of the main transformer current sensor SC81 is connected to the connection node in the third IGBT module VT33 and the fourth IGBT module VT34.

[0007] Furthermore, a grounding detection and high-voltage indication component is provided between the four-quadrant power module and the first power module, which includes a first voltage divider resistor R41, a second voltage divider resistor R42, a third voltage divider resistor R43, a grounding voltage sensor SV41, a first filter capacitor C41, and a first high-voltage indicator light LA41; one end of the first voltage sensor SV31 is connected to one end of the first voltage divider resistor R41, one end of the third voltage divider resistor R43, one end of the grounding voltage sensor SV41, and one end of the first filter capacitor C41; the other end of the first voltage divider resistor R41 is connected to the other end of the grounding voltage sensor SV41, the other end of the first filter capacitor C41, and one end of the second voltage divider resistor R42 and grounded; the other end of the third voltage divider resistor R43 is connected to one end of the first high-voltage indicator light LA41, and the other end of the first high-voltage indicator light LA41 is connected to the other end of the second voltage divider resistor R42 and the other end of the first voltage sensor SV31.

[0008] Furthermore, the first power module includes a fifth IGBT module VT11, a sixth IGBT module VT12, a seventh IGBT module VT13, an eighth IGBT module VT14, a second discharge resistor R11, a second supporting capacitor C11, a second voltage sensor SV11, a first current sensor SC11, and a second current sensor SC12; one end of the fifth IGBT module VT11, one end of the sixth IGBT module VT12, one end of the seventh IGBT module VT13, one end of the eighth IGBT module VT14, one end of the second discharge resistor R11, one end of the second supporting capacitor C11, and one end of the second voltage sensor SV11 are connected; the fifth IGBT module VT11... The other end of the first IGBT module VT12, the other end of the sixth IGBT module VT13, the other end of the eighth IGBT module VT14, the other end of the second discharge resistor R11, the other end of the second support capacitor C11, and the other end of the second voltage sensor SV11 are connected; one end of the first current sensor SC11 is connected to the connection node in the fifth IGBT module VT11; one end of the second current sensor SC12 is connected to the connection node in the sixth IGBT module VT12; the input end of the first drive traction motor is connected to the other end of the first current sensor SC11, the other end of the second current sensor SC12, and the connection node in the seventh IGBT module VT13, respectively. The second power module includes a ninth IGBT module VT21, a tenth IGBT module VT22, an eleventh IGBT module VT23, a twelfth IGBT module VT24, a third discharge resistor R21, a third support capacitor C21, a third voltage sensor SV21, a third current sensor SC21, and a fourth current sensor SC22; one end of the ninth IGBT module VT21, one end of the tenth IGBT module VT22, one end of the eleventh IGBT module VT23, one end of the twelfth IGBT module VT24, one end of the third discharge resistor R21, one end of the third support capacitor C21, one end of the third voltage sensor SV21, and one end of the first voltage sensor SV31 are connected; the other end of the ninth IGBT module VT21... The input terminals of the second drive traction motor are connected to the other ends of the tenth IGBT module VT22, the eleventh IGBT module VT23, the twelfth IGBT module VT24, the third discharge resistor R21, the third support capacitor C21, the third voltage sensor SV21, and the first voltage sensor SV31; one end of the third current sensor SC21 is connected to the connection node in the ninth IGBT module VT21; one end of the fourth current sensor SC22 is connected to the connection node in the tenth IGBT module VT22; and the input terminals of the second drive traction motor are respectively connected to the other ends of the third current sensor SC21, the fourth current sensor SC22, and the eleventh IGBT module VT23.

[0009] Furthermore, the first DC / DC output component includes a first reactor L51, a fifth current sensor SC51, a second filter capacitor C51, a second charging contactor KM51, a second charging resistor R51, a second main contactor KM52, a fourth voltage sensor SV51, a fourth voltage divider resistor R52, and a second high-voltage indicator LA51; one end of the first reactor L51 is connected to the connection node in the eighth IGBT module VT14; the other end of the first reactor L51 is connected to one end of the fifth current sensor SC51, and the other end of the fifth current sensor SC51 is connected to one end of the second filter capacitor C51 and one end of the second charging contactor KM51. One end of the second main contactor KM52 is connected; one end of the second charging resistor R51 is connected to the other end of the second charging contactor KM51, and the other end of the second charging resistor R51 is connected to the other end of the second main contactor KM52, one end of the fourth voltage sensor SV51, one end of the fourth voltage divider resistor R52, and the positive terminal of the first power battery; the other end of the second filter capacitor C51 is connected to the other end of the second discharge resistor R11, the other end of the fourth voltage sensor SV51, one end of the second high voltage indicator LA51, and the negative terminal of the first power battery; the other end of the fourth voltage divider resistor R52 is connected to the other end of the second high voltage indicator LA51. The second DC / DC output component includes a second reactor L61, a sixth current sensor SC61, a third filter capacitor C61, a third charging contactor KM61, a third charging resistor R61, a third main contactor KM62, a fifth voltage sensor SV61, a fifth voltage divider resistor R62, and a third high-voltage indicator LA61. One end of the second reactor L61 is connected to the connection node in the twelfth IGBT module VT24; the other end of the second reactor L61 is connected to one end of the sixth current sensor SC61, and the other end of the sixth current sensor SC61 is connected to one end of the third filter capacitor C61, one end of the third charging contactor KM62, and the third main contactor KM62. One end of the three main contactor KM62 is connected; one end of the third charging resistor R61 is connected to the other end of the third charging contactor KM61, and the other end of the third charging resistor R61 is connected to the other end of the third main contactor KM62, one end of the fifth voltage sensor SV61, one end of the fifth voltage divider resistor R62, and the positive terminal of the second power battery; the other end of the third filter capacitor C61 is connected to the other end of the third discharge resistor R21, the other end of the fifth voltage sensor SV61, one end of the third high voltage indicator LA61, and the negative terminal of the second power battery; the other end of the fifth voltage divider resistor R62 is connected to the other end of the third high voltage indicator LA61.

[0010] Furthermore, the medium-voltage auxiliary power supply assembly includes a fuse FU71, a diode D71, and an input contactor KM71; one end of the fuse FU71 is connected to one end of the first voltage sensor SV31; the other end of the fuse FU71 is connected to one end of the diode D71, the other end of the diode D71 is connected to one end of the input contactor KM71, the DC terminal of the auxiliary inverter module is connected to one end of the input contactor KM71 and the other end of the first voltage sensor SV31 respectively; the AC terminal of the auxiliary inverter module is connected to the cooling fan assembly and the preset auxiliary bus.

[0011] Furthermore, the high-voltage DC terminal of the charger power module is connected to both ends of the first voltage sensor SV31, and the low-voltage DC terminal of the charger power module is connected to a preset low-voltage DC bus and a preset battery.

[0012] This invention provides a main and auxiliary converter system suitable for the operation of electric locomotives in areas without grid connection, with the following advantages: (1) Environmentally friendly: Compared with traditional internal combustion locomotives or hybrid locomotives, it no longer produces toxic and harmful substances such as carbon oxides and nitrogen oxides, and the working environment of operators is friendly, which is beneficial to environmental protection and occupational health of operators. (2) Cost reduction and savings: Compared with traditional fuel-powered internal combustion locomotives or hybrid locomotives, it saves a lot of fuel procurement costs and internal combustion engine maintenance costs; (3) High energy utilization rate: The main and auxiliary converter units in the main and auxiliary converter system mentioned in this invention adopt AC drive, which has high transmission efficiency and the system has braking energy regeneration feedback function. When the vehicle brakes, the kinetic energy can be converted into electrical energy and stored in the power battery. (4) Flexible vehicle operation: In areas where it is inconvenient to install contact wires, such as when loading cargo, the present invention can supply power to the intermediate high-voltage circuit of the locomotive through the power battery via the traction and DC / DC power modules, so that the locomotive's travel path is not restricted by the contact wire; in areas where contact wires are installed, the power battery can be charged through the four-quadrant power module, traction and DC / DC power module during operation, saving the time of static charging of the locomotive in fixed areas by means of gun charging or pantograph charging, and improving work efficiency; (5) Advanced system topology: In this invention, the four-quadrant power module, traction and DC / DC power module can use the same IGBT module, support capacitor, current sensor and heat sink and other devices. The difference between the two power modules is only in the connection method of the busbar, which reduces the one-time development cost and cycle. (6) Low retrofit cost: The main and auxiliary converter cabinets use the secondary winding of the existing vehicle's main transformer, which can supply power to the main and auxiliary converter systems without affecting the operation of the existing DC drive system. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 This is a circuit diagram of the main and auxiliary converter system applicable to the operation of electric locomotives with multiple units in parallel in areas without grid access, as per the present invention. Figure 2 This is the electrical schematic diagram of the main transformer in this embodiment. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] This embodiment provides a main and auxiliary converter system suitable for the operation of electric locomotives in areas without grid grid connection, including main and auxiliary converter units installed in the main and auxiliary converter cabinet; such as Figure 1 As shown, the main and auxiliary converter units include a four-quadrant input component, a four-quadrant power module, a traction and DC / DC power module, a medium-voltage auxiliary power supply component, an auxiliary inverter module, and a charger power module; the traction and DC / DC power module includes a first power module and a second power module. The input terminal of the four-quadrant input component is connected to the main transformer; the output terminal of the four-quadrant input component is connected to the input terminal of the four-quadrant power module to realize AC power supply on / off control and current detection of the four-quadrant power module; the output terminal of the four-quadrant power module is connected to the first power module, the second power module, the auxiliary inverter module, and the charger power module respectively; the four-quadrant power module is used to convert the AC power output from the four-quadrant input component into high-voltage DC power; and the two ends of the medium-voltage auxiliary power supply component are respectively connected to one end of the four-quadrant power module and one end of the auxiliary inverter module; the other end of the auxiliary inverter module is connected to the cooling fan assembly; the medium-voltage auxiliary power supply component is used to cooperate with the auxiliary inverter module to realize power supply on / off control and overload protection; the cooling fan assembly is used to cool the modules in the main and auxiliary converter cabinets. The first power module and the second power module are respectively used to charge the preset first power battery and the second power battery by stepping down the high-voltage DC power output from the four-quadrant power module and charging the preset first power battery and the second power battery when there is a power grid; or to boost the DC power output from the first power battery and the second power battery through their DC / DC bridge arm and then convert the boosted DC power into AC power through their inverter bridge arm to power the preset first drive traction motor and the second drive traction motor when there is no power grid. A first DC / DC output component is provided between the first power module and the first power battery; a second DC / DC output component is provided between the second power module and the second power battery to realize the charging and discharging control of the first power battery and the second power battery, as well as battery voltage detection, battery charging current detection, battery discharging current detection, and high voltage indication of the power battery.

[0017] In this embodiment, the double-unit electric locomotive consists of two locomotives, A and B. During operation, one locomotive retains all its electrical and mechanical equipment, while the other locomotive has its traction electric drive system equipment removed, including but not limited to the excitation cabinet, chopper cabinet, main transformer, braking resistor, and DC traction motor. Based on this, the main and auxiliary converter system described in this embodiment is installed. For ease of description, it is assumed that the locomotive retaining all its electrical and mechanical equipment is locomotive A, and the locomotive undergoing modification is locomotive B. The main and auxiliary converter system in this embodiment consists of a main transformer, main and auxiliary converter cabinets, a power battery cabinet, and an AC traction motor. The main transformer reuses the main transformer of the existing locomotive A, and the stator frame of the AC traction motor reuses the stator frame of the existing DC traction motor. In areas with grid coverage, during traction operation, the locomotive's power source is the unmodified A section locomotive. Simultaneously, the secondary winding of the main transformer in section A supplies power to the main and auxiliary converter cabinets of section B locomotive, charging the power battery. During braking operation, in addition to the air brakes of sections A and B and the resistance braking of section A locomotive, the traction motor of section B locomotive operates in electric braking mode, feeding regenerative braking energy back to the grid or charging the battery through the main and auxiliary converter cabinets. In areas without grid coverage, during traction operation, the locomotive's power source is the modified B section locomotive. The power battery provides energy to the main and auxiliary converter cabinets, driving the traction motor. During braking operation, in addition to the air brakes of sections A and B locomotives, the traction motor of section B locomotive operates in electric braking mode, charging the battery through the main and auxiliary converter cabinets. In this embodiment, the main and auxiliary converter cabinet is the key core equipment of the main and auxiliary converter system, and the main and auxiliary converter units are set inside the main and auxiliary converter cabinet. It consists of one four-quadrant input component, one four-quadrant power module, two traction and DC / DC power modules, namely the first power module and the second power module, two DC / DC output components, one medium-voltage auxiliary power supply component, one auxiliary inverter module SIVMOD, two cooling fan components, one charger power module BCMOD, and one grounding detection and high-voltage indication component. In a specific embodiment, the four-quadrant input component includes a first charging contactor KM81, a first charging resistor R81, a first main contactor KM82, and an input current sensor SC81. One end of the first charging contactor KM81 is connected to the positive terminal interface of the secondary winding of the main transformer and one end of the first main contactor KM82. The other end of the first charging contactor KM81 is connected to one end of the first charging resistor R81. The other end of the first charging resistor R81 is connected to the other end of the first main contactor KM82. One end of the input current sensor SC81 is connected to the negative terminal interface of the secondary winding of the main transformer. In this embodiment, the four-quadrant input component is used to realize the power supply on / off control and current detection of the four-quadrant power module 4QSMOD.

[0018] In a specific embodiment, the four-quadrant power module includes a first IGBT module VT31, a second IGBT module VT32, a third IGBT module VT33, a fourth IGBT module VT34, a first discharge resistor R31, a first supporting capacitor C31, and a first voltage sensor SV31; one end of the first IGBT module VT31 is connected to one end of the second IGBT module VT32, one end of the third IGBT module VT33, one end of the fourth IGBT module VT34, one end of the first discharge resistor R31, one end of the first supporting capacitor C31, and one end of the first voltage sensor SV31, and is connected to the positive terminal of the high-voltage DC bus; the first... One end of IGBT module VT31 is connected to the other ends of the second IGBT module VT32, the third IGBT module VT33, the fourth IGBT module VT34, the first discharge resistor R31, the first support capacitor C31, and the first voltage sensor SV31, and is connected to the negative terminal of the high-voltage DC bus. The other end of the first charging resistor R81 is connected to the connection node in the first IGBT module VT31 and the second IGBT module VT32. The other end of the main transformer current sensor SC81 is connected to the connection node in the third IGBT module VT33 and the fourth IGBT module VT34. In this embodiment, the four-quadrant power module 4QSMOD is used to convert the AC power provided by the secondary winding of the main transformer into DC power in the grid area, and to supply power to the traction and DC / DC power modules, namely the first power module PWMOD1 and the second power module PWMOD2, the auxiliary inverter module SIVMOD, and the charger power module BCMOD, through the high-voltage DC bus. The connection node is the midpoint of the connection line of the series insulated-gate bipolar transistor in the IGBT module.

[0019] In a specific embodiment, a grounding detection and high-voltage indication component is further provided between the four-quadrant power module and the first power module. This component includes a first voltage divider resistor R41, a second voltage divider resistor R42, a third voltage divider resistor R43, a grounding voltage sensor SV41, a first filter capacitor C41, and a first high-voltage indicator light LA41. One end of the first voltage sensor SV41 is connected to one end of the first voltage divider resistor R41, one end of the third voltage divider resistor R43, one end of the grounding voltage sensor SV41, and one end of the first filter capacitor C41. The other end of the first voltage divider resistor R41 is connected to the other end of the grounding voltage sensor SV41, the other end of the first filter capacitor C41, and one end of the second voltage divider resistor R42 and grounded. The other end of the third voltage divider resistor R43 is connected to one end of the first high-voltage indicator light LA41, and the other end of the first high-voltage indicator light LA41 is connected to the other end of the second voltage divider resistor R42 and the other end of the first voltage sensor SV41. Specifically, one end of the first voltage divider resistor R41 is connected to the positive terminal of the high-voltage DC bus, and the other end is connected to one end of the second voltage divider resistor R42 and the vehicle body. The other end of the second voltage divider resistor R42 is connected to the negative terminal of the high-voltage DC bus. One end of the grounding voltage sensor SV41 and the first filter capacitor C41 are connected to the positive terminal of the high-voltage DC bus, and the other end is connected to the vehicle body. One end of the third voltage divider resistor R43 is connected to the positive terminal of the high-voltage DC bus, and the other end is connected to one end of the first high-voltage indicator light LA41. The other end of the first high-voltage indicator light LA41 is connected to the negative terminal of the high-voltage DC bus. In this embodiment, the grounding detection and high-voltage indication component is used to detect grounding faults on the positive and negative terminals of the high-voltage DC bus inside the cabinet and to indicate high voltage.

[0020] In a specific embodiment, the first power module includes a fifth IGBT module VT11, a sixth IGBT module VT12, a seventh IGBT module VT13, an eighth IGBT module VT14, a second discharge resistor R11, a second supporting capacitor C11, a second voltage sensor SV11, a first current sensor SC11, and a second current sensor SC12. One end of the fifth IGBT module VT11, one end of the sixth IGBT module VT12, one end of the seventh IGBT module VT13, one end of the eighth IGBT module VT14, one end of the second discharge resistor R11, one end of the second supporting capacitor C11, and one end of the second voltage sensor SV11 are connected and connected to the positive terminal of the high-voltage DC bus. The other ends of the fifth IGBT module VT11, the sixth IGBT module VT12, the seventh IGBT module VT13, the eighth IGBT module VT14, the second discharge resistor R11, the second supporting capacitor C11, and the second voltage sensor SV11 are connected and connected to the negative terminal of the high-voltage DC bus. One end of the first current sensor SC11 is connected to... The connection node in the fifth IGBT module VT11 is connected; one end of the second current sensor SC12 is connected to the connection node in the sixth IGBT module VT12; the input terminal of the first drive traction motor is connected to the other end of the first current sensor SC11, the other end of the second current sensor SC12, and the connection node in the seventh IGBT module VT13, respectively. That is, the other end of the first current sensor SC11 is connected to the U-phase interface of the traction motor TM1, the other end of the second current sensor SC12 is connected to the V-phase interface of the traction motor TM1, and the connection node, i.e., the midpoint, in the seventh IGBT module VT13 is connected to the W-phase interface of the traction motor TM1; in this embodiment, the DC / DC bridge arm of the first power module PWMOD1, i.e., the eighth IGBT module VT14, is used to step down the voltage of the high-voltage DC bus to charge the first power battery in the grid area, and to step up the power of the power battery in the gridless area. Then, through the three sets of inverter bridge arms of the first power module PWMOD1, i.e., the fifth IGBT module VT11, the sixth IGBT module VT12, and the seventh IGBT module VT13, it is converted into three-phase AC power to drive the first drive traction motor TM1 to rotate.

[0021] The second power module includes a ninth IGBT module VT21, a tenth IGBT module VT22, an eleventh IGBT module VT23, a twelfth IGBT module VT24, a third discharge resistor R21, a third support capacitor C21, a third voltage sensor SV21, a third current sensor SC21, and a fourth current sensor SC22. One end of the ninth IGBT module VT21, one end of the tenth IGBT module VT22, one end of the eleventh IGBT module VT23, one end of the twelfth IGBT module VT24, one end of the third discharge resistor R21, one end of the third support capacitor C21, one end of the third voltage sensor SV21, and one end of the first voltage sensor SV31 are connected and connected to the positive terminal of the high-voltage DC bus. The other ends of the ninth IGBT module VT21, the tenth IGBT module VT22, the eleventh IGBT module VT23, and the twelfth IGBT module VT24 are connected to the positive terminal of the high-voltage DC bus. The other end, the other end of the third discharge resistor R21, the other end of the third support capacitor C21, the other end of the third voltage sensor SV21, and the other end of the first voltage sensor SV31 are connected and connected to the negative terminal of the high voltage DC bus; one end of the third current sensor SC21 is connected to the connection node in the ninth IGBT module VT21; one end of the fourth current sensor SC22 is connected to the connection node in the tenth IGBT module VT22; the input terminal of the second drive traction motor is connected to the other end of the third current sensor SC21, the other end of the fourth current sensor SC22, and the connection node in the eleventh IGBT module VT23, respectively. That is, the other end of the third current sensor SC21 is connected to the U-phase interface of the traction motor TM2, the other end of the fourth current sensor SC22 is connected to the V-phase interface of the traction motor TM2, and the connection node, i.e., the midpoint, in the eleventh IGBT module VT23 is connected to the W-phase interface of the traction motor TM2.

[0022] In this embodiment, the DC / DC bridge arm of the second power module PWMOD2, namely the twelfth IGBT module VT24, steps down the voltage of the high-voltage DC bus to charge the second power battery in the area with grid, and boosts the power battery in the area without grid. Then, through the three sets of inverter bridge arms of the second power module PWMOD2, namely the ninth IGBT module VT21, the tenth IGBT module VT22, and the eleventh IGBT module VT23, it is converted into three-phase AC power to drive the second drive traction motor TM2 to rotate. In a specific embodiment, the first DC / DC output component includes a first reactor L51, a fifth current sensor SC51, a second filter capacitor C51, a second charging contactor KM51, a second charging resistor R51, a second main contactor KM52, a fourth voltage sensor SV51, a fourth voltage divider resistor R52, and a second high-voltage indicator LA51. One end of the first reactor L51 is connected to a connection node in the eighth IGBT module VT14; the other end of the first reactor L51 is connected to one end of the fifth current sensor SC51, and the other end of the fifth current sensor SC51 is connected to one end of the second filter capacitor C51, one end of the second charging contactor KM51, and one end of the second main contactor KM52; one end of the second charging resistor R51 is connected to the other end of the second charging contactor KM51, and the other end of the second charging resistor R51 is connected to the other end of the second main contactor KM52. One end of the fourth voltage sensor SV51, one end of the fourth voltage divider resistor R52, and the positive terminal of the first power battery are connected; the other end of the second filter capacitor C51 is connected to the other end of the second discharge resistor R11, the other end of the fourth voltage sensor SV51, one end of the second high-voltage indicator LA51, and the negative terminal of the first power battery; the other end of the fourth voltage divider resistor R52 is connected to the other end of the second high-voltage indicator LA51; and the other ends of the second filter capacitor C51, the fourth voltage sensor SV51, the second high-voltage indicator LA51, and the negative terminal of the first power battery are respectively connected to the negative terminal of the high-voltage DC bus; in this embodiment, the first DC / DC output component, together with the first power module PWMOD1, realizes the charging and discharging control of the first power battery, battery voltage detection, battery charging current detection, battery discharging current detection, and high-voltage indication of the power battery; The second DC / DC output component includes a second reactor L61, a sixth current sensor SC61, a third filter capacitor C61, a third charging contactor KM61, a third charging resistor R61, a third main contactor KM62, a fifth voltage sensor SV61, a fifth voltage divider resistor R62, and a third high-voltage indicator LA61. One end of the second reactor L61 is connected to the connection node in the twelfth IGBT module VT24; the other end of the second reactor L61 is connected to one end of the sixth current sensor SC61, and the other end of the sixth current sensor SC61 is connected to one end of the third filter capacitor C61, one end of the third charging contactor KM62, and the third main contactor KM62. One end of the three main contactor KM62 is connected; one end of the third charging resistor R61 is connected to the other end of the third charging contactor KM61, and the other end of the third charging resistor R61 is connected to the other end of the third main contactor KM62, one end of the fifth voltage sensor SV61, one end of the fifth voltage divider resistor R62, and the positive terminal of the second power battery; the other end of the third filter capacitor C61 is connected to the other end of the third discharge resistor R21, the other end of the fifth voltage sensor SV61, one end of the third high-voltage indicator LA61, and the negative terminal of the second power battery; the other end of the fifth voltage divider resistor R62 is connected to the other end of the third high-voltage indicator LA61. Furthermore, the other ends of the third filter capacitor C61, the fifth voltage sensor SV61, the third high-voltage indicator LA61, and the negative terminal of the second power battery are respectively connected to the negative terminal of the high-voltage DC bus; in this embodiment, the second DC / DC output component, in conjunction with the second power module PWMOD2, realizes the charging and discharging control of the second power battery, battery voltage detection, battery charging current detection, battery discharging current detection, and high-voltage indication of the power battery; In a specific embodiment, the medium-voltage auxiliary power supply assembly includes a fuse FU71, a diode D71, and an input contactor KM71. One end of the fuse FU71 is connected to one end of the first voltage sensor SV31; the other end of the fuse FU71 is connected to one end of the diode D71, and the other end of the diode D71 is connected to one end of the input contactor KM71. The DC terminal of the auxiliary inverter module is connected to one end of the input contactor KM71 and the other end of the first voltage sensor SV31, respectively. The AC terminal of the auxiliary inverter module is connected to the cooling fan assembly and the pre-installed auxiliary bus. In this embodiment, the medium-voltage auxiliary power supply assembly is used in conjunction with the auxiliary inverter module SIVMOD to achieve input power supply on / off control and overload protection. The auxiliary inverter module SIVMOD is used to convert the high-voltage DC power supply from the high-voltage DC bus in the main and auxiliary converter cabinets into a 50Hz AC 380V AC power supply. In this embodiment, the cooling fan assembly includes a first cooling fan assembly and a second cooling fan assembly. The first cooling fan assembly consists of a circuit breaker QF71, a contactor KM73, a current sensor SC71, a current sensor SC72, ​​and a cooling fan FAN1. The second cooling fan assembly consists of a circuit breaker QF72, a contactor KM74, a current sensor SC73, a current sensor SC74, and a cooling fan FAN2. The first and second cooling fan assemblies work together to cool the components inside the cabinet. Specifically, in this embodiment, one end of the fuse FU71 is connected to the positive terminal of the high-voltage DC bus, and the other end is connected to one end of the diode D71. The other end of the diode D71 is connected to one end of the input contactor KM71, and the other end of the input contactor KM71 is connected to the positive DC input terminal of the auxiliary inverter module SIVMOD. The negative DC input terminal of the auxiliary inverter module SIVMOD is connected to the negative terminal of the high-voltage DC bus. The U, V, and W phase outputs of the auxiliary inverter module SIVMOD are connected to the U, V, and W phase interfaces of the vehicle auxiliary bus, and one side of the three-phase interfaces of circuit breakers QF71 and QF72, respectively. The other side of the three-phase interface of circuit breaker QF71 is connected to one side of the three-phase interface of contactor KM73. The other side of the three-phase interface of circuit breaker QF72 is connected to one side of the three-phase interface of contactor KM74. The other side of the three-phase interface of contactor KM73 is connected to the three-phase interface of wind turbine FAN1. Current transformers SC71 and SC72 are connected in series in the U and V phase connections, respectively. The other side of the three-phase interface of contactor KM74 is connected to the three-phase interface of wind turbine FAN2. Current transformers SC73 and SC74 are connected in series in the U and V phase connections, respectively. The N phase output of the auxiliary inverter module SIVMOD is connected to the N phase interface of the vehicle auxiliary bus.

[0023] In a specific embodiment, the high-voltage DC terminal of the charger power module is connected to both ends of the first voltage sensor SV31, and the low-voltage DC terminal of the charger power module is connected to a preset low-voltage DC bus and a preset battery. Specifically, the positive input interface of the charger power module BCMOD is connected to the positive terminal of the high-voltage DC bus, and the negative input interface is connected to the negative terminal of the high-voltage DC bus. The low-voltage output interface of the charger power module BCMOD is connected to the positive terminal of the vehicle's low-voltage DC bus, the negative terminal of the low-voltage DC bus, and the positive terminal of the battery, respectively, to convert the high-voltage DC power supply of the high-voltage DC bus in the main and auxiliary converter cabinet into DC110V or DC24V DC power supply to power the vehicle's low-voltage DC bus and charge the on-board low-voltage battery.

[0024] This specific example consists of one main transformer, two main and auxiliary converter cabinets, four power battery cabinets, and four AC traction motors. The main transformer reuses the existing vehicle's main transformer, and the stator frame of the AC traction motors reuses the stator frame of the existing vehicle's DC traction motors. The two main and auxiliary converter cabinets each utilize two sets of secondary windings from the existing vehicle's main transformer, specifically portions of the two Dy2 traction windings of the main transformer. For example... Figure 2 As shown, the four-quadrant input of the main and auxiliary converter cabinet 1 is taps a1 and b1 in the a1-b1-x1 winding; the four-quadrant input of the main and auxiliary converter cabinet 2 is taps a3 and b3 in the a3-b3-x3 winding.

[0025] (1) Locomotives with multiple units running in the networked area: When the double-unit locomotive is running in a grid area, the pantograph of locomotive A is raised and the main circuit breaker is closed. The AC voltage between the positive and negative terminals of the secondary winding of the main transformer is introduced into the main and auxiliary converter cabinet, specifically, AC 347.7V. At this time, the charging contactor KM81 closes, and the AC input power is charged through the charging contactor KM81 and the charging resistor R81 to the supporting capacitor C31 of the four-quadrant power module 4QSMOD, the supporting capacitor C11 of the traction and DC / DC power module PWMOD1, and the supporting capacitor C21 of the traction and DC / DC power module PWMOD2. Subsequently, the main contactor KM82 closes, the charging contactor KM81 opens, and the IGBT modules VT31, VT32, VT33, and VT34 of the four-quadrant power module 4QSMOD alternately turn on their upper and lower switching transistors, converting the AC input power into a high-voltage DC power, specifically DC 830V. When the main contactor KM52 of the first DC / DC output component is closed, the IGBT module VT14 of the traction and DC / DC power module PWMOD1 turns on its upper tube, and the high voltage DC power supply of the high voltage DC bus is stepped down to charge the first power battery. When the main contactor KM62 of the second DC / DC output component closes, the IGBT module VT24 of the traction and DC / DC power module PWMOD2 turns on its upper tube, and the high voltage DC power supply of the high voltage DC bus is stepped down to charge the second power battery. When the input contactor KM71 of the medium-voltage auxiliary power supply component is closed, the auxiliary inverter module SIVMOD converts the high-voltage DC power of the high-voltage DC bus into a 50Hz AC380V AC power supply to power the vehicle auxiliary bus and cooling fans FAN1 and FAN2. The charger power module BCMOD converts the high-voltage DC power supply of the high-voltage DC bus in the cabinet into DC110V or DC24V DC power supply to power the vehicle's low-voltage DC bus and charge the vehicle's low-voltage battery.

[0026] (2) Locomotives with multiple units running in areas without power grids: When the double-unit locomotive is running in an area without a power grid, neither the four-quadrant input component nor the four-quadrant power module 4QSMOD will work.

[0027] When the charging contactor KM51 of the first DC / DC output component closes, the power supply of the first power battery charges the filter capacitor C51, the supporting capacitor C11 of the traction and DC / DC power module PWMOD1, the supporting capacitor C21 of the traction and DC / DC power module PWMOD2, and the supporting capacitor C31 of the four-quadrant power module 4QSMOD through the charging resistor R51. Then, the main contactor KM52 closes, the charging contactor KM51 opens, and the IGBT module VT14 of the traction and DC / DC power module PWMOD1 turns on its lower transistor, boosting the high-voltage DC power supply of the first power battery to supply power to the high-voltage DC bus, specifically, it can be DC 830V. The IGBT modules VT11, VT12, and VT13 of the traction and DC / DC power module PWMOD1 alternately turn on their upper and lower transistors, converting the high-voltage DC power supply of the high-voltage DC bus into a three-phase AC power with adjustable frequency and voltage to supply power to the traction motor TM1. When the charging contactor KM61 of the second DC / DC output component closes, the power supply of the second power battery charges the filter capacitor C61, the supporting capacitor C11 of the traction and DC / DC power module PWMOD1, the supporting capacitor C21 of the traction and DC / DC power module PWMOD2, and the supporting capacitor C31 of the four-quadrant power module 4QSMOD through the charging resistor R61. Then, the main contactor KM62 closes, the charging contactor KM61 opens, and the IGBT module VT24 of the traction and DC / DC power module PWMOD2 turns on its lower transistor, boosting the high-voltage DC power supply of the second power battery to supply power to the high-voltage DC bus, specifically, DC 830V. The IGBT modules VT21, VT22, and VT23 of the traction and DC / DC power module PWMOD2 alternately turn on their upper and lower transistors, converting the high-voltage DC power supply of the high-voltage DC bus into a three-phase AC power with adjustable frequency and voltage to supply power to the traction motor TM2. When the input contactor KM71 of the medium-voltage auxiliary power supply component is closed, the auxiliary inverter module SIVMOD converts the high-voltage DC power of the high-voltage DC bus into a 50Hz AC380V AC power supply to power the vehicle auxiliary bus and cooling fans FAN1 and FAN2. The charger power module BCMOD converts the high-voltage DC power supply of the high-voltage DC bus in the cabinet into DC110V or DC24V DC power supply to power the vehicle's low-voltage DC bus and charge the vehicle's low-voltage battery.

[0028] Compared with the prior art, the beneficial effects of the system described in this embodiment are as follows: (1) Environmentally friendly: Compared with traditional internal combustion locomotives or hybrid locomotives, it no longer produces toxic and harmful substances such as carbon oxides and nitrogen oxides, and the working environment of operators is friendly, which is beneficial to environmental protection and occupational health of operators. (2) Cost reduction and savings: Compared with traditional fuel-powered internal combustion locomotives or hybrid locomotives, it saves a lot of fuel procurement costs and internal combustion engine maintenance costs; (3) High energy utilization rate: The main and auxiliary converter units in the main and auxiliary converter system mentioned in this invention adopt AC drive, which has high transmission efficiency and the system has braking energy regeneration feedback function. When the vehicle brakes, the kinetic energy can be converted into electrical energy and stored in the power battery. (4) Flexible vehicle operation: In areas where it is inconvenient to install contact wires, such as when loading cargo, the present invention can supply power to the intermediate high-voltage circuit of the locomotive through the power battery via the traction and DC / DC power modules, so that the locomotive's travel path is not restricted by the contact wire; in areas where contact wires are installed, the power battery can be charged through the four-quadrant power module, traction and DC / DC power module during operation, saving the time of static charging of the locomotive in fixed areas by means of gun charging or pantograph charging, and improving work efficiency; (5) Advanced system topology: In this invention, the four-quadrant power module, traction and DC / DC power module can use the same IGBT module, support capacitor, current sensor and heat sink and other devices. The difference between the two power modules is only in the connection method of the busbar, which reduces the one-time development cost and cycle. (6) Low retrofit cost: The main and auxiliary converter cabinets use the secondary winding of the existing vehicle's main transformer, which can supply power to the main and auxiliary converter systems without affecting the operation of the existing DC drive system.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A main and auxiliary converter system suitable for operation of electric locomotives in areas without power grid connection, characterized in that, It includes a main and auxiliary converter unit installed in the main and auxiliary converter cabinet; and the main and auxiliary converter unit includes a four-quadrant input component, a four-quadrant power module, a traction and DC / DC power module, a medium-voltage auxiliary power supply component, an auxiliary inverter module, and a charger power module; the traction and DC / DC power module includes a first power module and a second power module; The input terminal of the four-quadrant input component is connected to the main transformer; the output terminal of the four-quadrant input component is connected to the input terminal of the four-quadrant power module to realize AC power supply on / off control and current detection of the four-quadrant power module; the output terminal of the four-quadrant power module is connected to the first power module, the second power module, the auxiliary inverter module, and the charger power module respectively; the four-quadrant power module is used to convert the AC power output from the four-quadrant input component into high-voltage DC power; and the two ends of the medium-voltage auxiliary power supply component are respectively connected to one end of the four-quadrant power module and one end of the auxiliary inverter module; the other end of the auxiliary inverter module is connected to the cooling fan assembly; the medium-voltage auxiliary power supply component is used to cooperate with the auxiliary inverter module to realize power supply on / off control and overload protection; the cooling fan assembly is used to cool the modules in the main and auxiliary converter cabinets. The first power module and the second power module are respectively used to charge the preset first power battery and the second power battery by stepping down the high-voltage DC power output from the four-quadrant power module and charging the preset first power battery and the second power battery when there is a power grid; or to boost the DC power output from the first power battery and the second power battery through their DC / DC bridge arm and then convert the boosted DC power into AC power through their inverter bridge arm to power the preset first drive traction motor and the second drive traction motor when there is no power grid. A first DC / DC output component is provided between the first power module and the first power battery; a second DC / DC output component is provided between the second power module and the second power battery to realize the charging and discharging control of the first power battery and the second power battery, as well as battery voltage detection, battery charging current detection, battery discharging current detection, and high voltage indication of the power battery.

2. The main and auxiliary converter system for operation of electric locomotives in non-grid areas with multiple units in series, as described in claim 1, is characterized in that... The four-quadrant input component includes a first charging contactor KM81, a first charging resistor R81, a first main contactor KM82, and an input current sensor SC81. One end of the first charging contactor KM81 is connected to the positive terminal interface of the secondary winding of the main transformer and one end of the first main contactor KM82. The other end of the first charging contactor KM81 is connected to one end of the first charging resistor R81. The other end of the first charging resistor R81 is connected to the other end of the first main contactor KM82. One end of the input current sensor SC81 is connected to the negative terminal interface of the secondary winding of the main transformer.

3. The main and auxiliary converter system for operation of electric locomotives in non-grid areas with multiple units in series, as described in claim 2, is characterized in that... The four-quadrant power module includes a first IGBT module VT31, a second IGBT module VT32, a third IGBT module VT33, a fourth IGBT module VT34, a first discharge resistor R31, a first support capacitor C31, and a first voltage sensor SV31; one end of the first IGBT module VT31 is connected to one end of the second IGBT module VT32, one end of the third IGBT module VT33, one end of the fourth IGBT module VT34, one end of the first discharge resistor R31, one end of the first support capacitor C31, and one end of the first voltage sensor SV31; the first IGBT module VT31... The other end of the IGBT module VT31 is connected to the other end of the second IGBT module VT32, the other end of the third IGBT module VT33, the other end of the fourth IGBT module VT34, the other end of the first discharge resistor R31, the other end of the first support capacitor C31, and the other end of the first voltage sensor SV31; the other end of the first charging resistor R81 is connected to the connection node in the first IGBT module VT31 and the second IGBT module VT32; the other end of the input current sensor SC81 is connected to the connection node in the third IGBT module VT33 and the fourth IGBT module VT34.

4. The main and auxiliary converter system for operation of electric locomotives in non-grid areas with multiple units in series, as described in claim 3, is characterized in that... A grounding detection and high-voltage indication component is also provided between the four-quadrant power module and the first power module. This component includes a first voltage divider resistor R41, a second voltage divider resistor R42, a third voltage divider resistor R43, a grounding voltage sensor SV41, a first filter capacitor C41, and a first high-voltage indicator light LA41. One end of the first voltage sensor SV41 is connected to one end of the first voltage divider resistor R41, one end of the third voltage divider resistor R43, one end of the grounding voltage sensor SV41, and one end of the first filter capacitor C41. The other end of the first voltage divider resistor R41 is connected to the other end of the grounding voltage sensor SV41, the other end of the first filter capacitor C41, and one end of the second voltage divider resistor R42 and grounded. The other end of the third voltage divider resistor R43 is connected to one end of the first high-voltage indicator light LA41, and the other end of the first high-voltage indicator light LA41 is connected to the other end of the second voltage divider resistor R42 and the other end of the first voltage sensor SV41.

5. A main and auxiliary converter system for operation of electric locomotives in non-grid areas with multiple units coupled together, as described in claim 4, is characterized in that... The first power module includes a fifth IGBT module VT11, a sixth IGBT module VT12, a seventh IGBT module VT13, an eighth IGBT module VT14, a second discharge resistor R11, a second support capacitor C11, a second voltage sensor SV11, a first current sensor SC11, and a second current sensor SC12; one end of the fifth IGBT module VT11, one end of the sixth IGBT module VT12, one end of the seventh IGBT module VT13, one end of the eighth IGBT module VT14, one end of the second discharge resistor R11, one end of the second support capacitor C11, and one end of the second voltage sensor SV11 are connected; the other end of the fifth IGBT module VT11... The first IGBT module VT11 is connected to the other end of the sixth IGBT module VT12, the other end of the seventh IGBT module VT13, the other end of the eighth IGBT module VT14, the other end of the second discharge resistor R11, the other end of the second support capacitor C11, and the other end of the second voltage sensor SV11; one end of the first current sensor SC11 is connected to the connection node in the fifth IGBT module VT11; one end of the second current sensor SC12 is connected to the connection node in the sixth IGBT module VT12; the input terminal of the first drive traction motor is connected to the other end of the first current sensor SC11, the other end of the second current sensor SC12, and the connection node in the seventh IGBT module VT13, respectively. The second power module includes a ninth IGBT module VT21, a tenth IGBT module VT22, an eleventh IGBT module VT23, a twelfth IGBT module VT24, a third discharge resistor R21, a third support capacitor C21, a third voltage sensor SV21, a third current sensor SC21, and a fourth current sensor SC22; one end of the ninth IGBT module VT21, one end of the tenth IGBT module VT22, one end of the eleventh IGBT module VT23, one end of the twelfth IGBT module VT24, one end of the third discharge resistor R21, one end of the third support capacitor C21, one end of the third voltage sensor SV21, and one end of the first voltage sensor SV31 are connected; the other end of the ninth IGBT module VT21... The input terminals of the second drive traction motor are connected to the other ends of the tenth IGBT module VT22, the eleventh IGBT module VT23, the twelfth IGBT module VT24, the third discharge resistor R21, the third support capacitor C21, the third voltage sensor SV21, and the first voltage sensor SV31; one end of the third current sensor SC21 is connected to the connection node in the ninth IGBT module VT21; one end of the fourth current sensor SC22 is connected to the connection node in the tenth IGBT module VT22; and the input terminals of the second drive traction motor are respectively connected to the other ends of the third current sensor SC21, the fourth current sensor SC22, and the eleventh IGBT module VT23.

6. The main and auxiliary converter system for operation of electric locomotives in non-grid areas with multiple units in series, as described in claim 5, is characterized in that... The first DC / DC output component includes a first reactor L51, a fifth current sensor SC51, a second filter capacitor C51, a second charging contactor KM51, a second charging resistor R51, a second main contactor KM52, a fourth voltage sensor SV51, a fourth voltage divider resistor R52, and a second high-voltage indicator LA51. One end of the first reactor L51 is connected to the connection node in the eighth IGBT module VT14; the other end of the first reactor L51 is connected to one end of the fifth current sensor SC51, and the other end of the fifth current sensor SC51 is connected to one end of the second filter capacitor C51, one end of the second charging contactor KM51, and the second main contactor KM52. One end of the main contactor KM52 is connected; one end of the second charging resistor R51 is connected to the other end of the second charging contactor KM51, and the other end of the second charging resistor R51 is connected to the other end of the second main contactor KM52, one end of the fourth voltage sensor SV51, one end of the fourth voltage divider resistor R52, and the positive terminal of the first power battery; the other end of the second filter capacitor C51 is connected to the other end of the second discharge resistor R11, the other end of the fourth voltage sensor SV51, one end of the second high voltage indicator LA51, and the negative terminal of the first power battery; the other end of the fourth voltage divider resistor R52 is connected to the other end of the second high voltage indicator LA51. The second DC / DC output component includes a second reactor L61, a sixth current sensor SC61, a third filter capacitor C61, a third charging contactor KM61, a third charging resistor R61, a third main contactor KM62, a fifth voltage sensor SV61, a fifth voltage divider resistor R62, and a third high-voltage indicator LA61. One end of the second reactor L61 is connected to the connection node in the twelfth IGBT module VT24; the other end of the second reactor L61 is connected to one end of the sixth current sensor SC61, and the other end of the sixth current sensor SC61 is connected to one end of the third filter capacitor C61, one end of the third charging contactor KM62, and the third main contactor KM62. One end of the three main contactor KM62 is connected; one end of the third charging resistor R61 is connected to the other end of the third charging contactor KM61, and the other end of the third charging resistor R61 is connected to the other end of the third main contactor KM62, one end of the fifth voltage sensor SV61, one end of the fifth voltage divider resistor R62, and the positive terminal of the second power battery; the other end of the third filter capacitor C61 is connected to the other end of the third discharge resistor R21, the other end of the fifth voltage sensor SV61, one end of the third high voltage indicator LA61, and the negative terminal of the second power battery; the other end of the fifth voltage divider resistor R62 is connected to the other end of the third high voltage indicator LA61.

7. A main and auxiliary converter system for operation of electric locomotives in non-grid areas with multiple units coupled together, as described in claim 6, is characterized in that... The medium-voltage auxiliary power supply assembly includes a fuse FU71, a diode D71, and an input contactor KM71. One end of the fuse FU71 is connected to one end of the first voltage sensor SV31. The other end of the fuse FU71 is connected to one end of the diode D71, and the other end of the diode D71 is connected to one end of the input contactor KM71. The DC terminal of the auxiliary inverter module is connected to one end of the input contactor KM71 and the other end of the first voltage sensor SV31, respectively. The AC terminal of the auxiliary inverter module is connected to the cooling fan assembly and the pre-installed auxiliary bus.

8. A main and auxiliary converter system for operation of electric locomotives in non-grid areas with multiple units connected, as described in claim 7, is characterized in that... The high-voltage DC terminal of the charger power module is connected to both ends of the first voltage sensor SV31, and the low-voltage DC terminal of the charger power module is connected to a preset low-voltage DC bus and a preset battery.

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