Electric locomotive and power supply system and control method thereof

Abstract

This invention discloses an electric locomotive and its power supply system and control method. The power supply system further includes a traction battery pack, a first control switch, a bidirectional charger, and a second control switch. The traction battery pack is connected to a control load via the first control switch, which is a manual switch. The control load includes a charger control device. The traction battery pack is also connected to the bidirectional charger via the second control switch. The bidirectional charger is connected to the auxiliary power supply device and different loads. This invention eliminates the need for a control battery and its charger, supplying power to the control load from the traction battery pack or from the overhead contact line converted by the bidirectional charger. This solves the problems of limited usage scenarios caused by the control battery's inability to perform traction self-propelled operation and power supply during maintenance windows, as well as the space occupied in the machine room due to the additional traction battery pack.

Description

Technical Field

[0001] This invention belongs to the field of rail transit technology, and in particular relates to an electric locomotive and its power supply system and control method. Background Technology

[0002] Currently, the control system of electric locomotives (such as the HXD1 freight electric locomotive) draws power from the control battery to perform the vehicle's control functions. However, due to limitations in the control battery's capacity, voltage level, and cable current carrying capacity, the control battery can only be used as a control load power source and cannot achieve functions such as traction self-propelled movement or power supply for daily life during maintenance breaks, thus limiting the locomotive's usage scenarios. If an additional traction battery (or power battery) is added to the electric locomotive to achieve functions such as traction self-propelled movement and power supply for daily life during maintenance breaks, it will occupy space in the engine room and require additional components such as traction battery chargers, making the already power-concentrated electric locomotive equipment layout even more compact and hindering the overall platform design of the vehicle.

[0003] Therefore, designing a topology circuit and control method that integrates traction and control batteries to achieve the integration of traction and control batteries, thereby enabling locomotives to achieve traction self-propelled operation in grid-free areas, power supply during maintenance windows, and power supply for control purposes, is an urgent technical problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to provide an electric locomotive and its power supply system and control method to solve the problems that the control battery cannot realize functions such as traction self-propelled driving and power supply during maintenance windows, which limits the locomotive's usage scenarios, and that the additional traction battery occupies space in the machine room.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution: an electric locomotive power supply system, comprising a contact network, a traction transformer, a traction converter, and an auxiliary power supply device connected in sequence; the power supply system further comprises a traction battery pack, a first control switch, a bidirectional charger, and a second control switch; the traction battery pack is connected to a control load through the first control switch, the first control switch being a manual switch, and the control load including a charger control device; the traction battery pack is also connected to the bidirectional charger through the second control switch, and the bidirectional charger is connected to the auxiliary power supply device and different loads;

[0006] The opening and closing of the first and second control switches are controlled according to the locomotive power supply mode and the state of charge of the traction battery pack.

[0007] Furthermore, the traction battery pack includes at least one individual battery cell.

[0008] Furthermore, the single-cell battery is a lithium titanate battery.

[0009] Furthermore, the second control switch is a manual switch or a double-pole contactor.

[0010] Furthermore, the manual switch is a double-pole manual switch or two single-pole manual switches.

[0011] Furthermore, an anti-reverse diode is connected in series between the traction battery pack and the first control switch.

[0012] Furthermore, the different loads connected to the bidirectional charger include traction loads and auxiliary loads.

[0013] Based on the same concept, the present invention also provides a control method for the electric locomotive power supply system as described above, comprising:

[0014] When the overhead contact line is powered and SOC q <SOC qmax At this time, the first control switch is closed first, and then the second control switch is closed. The contact network sequentially charges the traction battery pack, supplies power to the control load and different loads connected to the bidirectional charger through the traction transformer, traction converter, auxiliary power supply device and bidirectional charger.

[0015] When the overhead contact line is powered and SOC q ≥SOC qmax At this time, the first control switch is closed first, and then the second control switch is closed. The contact network supplies power to the control load and different loads connected to the bidirectional charger in sequence through the traction transformer, traction converter, auxiliary power supply device, and bidirectional charger.

[0016] When the traction battery pack is powered and SOC q ≥SOC qmin At this time, first control switch is closed, then control switch is closed. Traction battery pack supplies power to control load through first control switch, and traction battery pack supplies power to different loads connected to bidirectional charger through second control switch and bidirectional charger.

[0017] When the overhead contact line and traction battery pack are powered and SOC q ≥SOC qmin When the first control switch is closed and the second control switch is open, the traction battery pack supplies power to the control load through the first control switch. The contact network supplies power to different loads connected to the bidirectional charger through the traction transformer, traction converter, auxiliary power supply device, and bidirectional charger in sequence.

[0018] Among them, SOC q State of charge (SOC) of the traction battery pack qmax State of Charge (SOC) is the upper limit of normal charging and discharging of the traction battery pack. qminThis represents the lower limit of normal charging and discharging values ​​for the traction battery pack.

[0019] Based on the same concept, the present invention also provides an electric locomotive, on which a power supply system as described above is provided.

[0020] Beneficial effects

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] This invention eliminates the control battery and its charger, supplying power to the control load from the traction battery pack or from the overhead contact line converted by the bidirectional charger. In applications such as self-propelled operation in areas without overhead contact lines, during maintenance windows, in-depot operation, or when the control load draws power, the traction battery pack supplies power to the control load and different loads connected to the bidirectional charger. This solves the problem of limited application scenarios caused by the control battery's inability to perform functions such as traction self-propelled operation and power supply during maintenance windows. By eliminating the control battery and its charger, the problem of space occupation in the mechanical compartment due to the additional traction battery pack is solved, improving the power supply redundancy and reliability of the entire locomotive's control load. Attached Figure Description

[0023] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a structural block diagram of the electric locomotive power supply system in an embodiment of the present invention. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0026] The technical solutions of this application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0027] Because the control load and traction load have different power supply circuits, they are powered separately. The control load is powered by a control battery, while the traction load is powered by the overhead contact line. The control battery has a small capacity and cannot power the traction load, making the locomotive unsuitable for special scenarios such as traction of self-propelled trains, track maintenance windows, or trains within the depot. Therefore, an additional traction battery and its charger are needed to provide traction power for these special scenarios. This results in the added traction battery and charger occupying space in the engine room, making the already centralized power locomotive equipment layout even more compact and hindering the overall platform design of the vehicle.

[0028] Based on the above-mentioned technical problems, the present invention provides a power supply system and control method for electric locomotives, which eliminates the control battery and its charger, and uses traction battery packs or overhead contact lines to supply power to the control load, so that there is only one set of battery and charger on the electric locomotive, reducing the space occupied in the mechanical compartment and improving the redundancy and reliability of the power supply to the control load.

[0029] Example 1

[0030] like Figure 1 As shown in the figure, an electric locomotive power supply system provided by an embodiment of the present invention includes a contact network, a traction transformer, a traction converter, and an auxiliary power supply device connected in sequence. The power supply system also includes a traction battery pack, a first control switch K11 / K12, a bidirectional charger, and a second control switch K21 / K22. The traction battery pack is connected to a control load through the first control switch K11 / K12, which is a manual switch. The control load includes a charger control device. The traction battery pack is also connected to the bidirectional charger through the second control switch K21 / K22. The bidirectional charger is connected to the auxiliary power supply device and different loads.

[0031] Based on the locomotive's power supply mode and the state of charge of the traction battery pack, the first control switch K11 / K12 and the second control switch K21 / K22 are opened and closed to enable the traction battery pack or the contact network to supply power to the control load, thereby canceling the control battery and its charger. At the same time, in special scenarios, the traction battery pack can supply power to various loads, ensuring the normal operation of the electric locomotive in special scenarios.

[0032] Let SOC q For the traction battery pack's state of charge (SOC) qmax The upper limit of normal charging and discharging of the traction battery pack, and the state of charge (SOC). qmin The lower limit for normal charging and discharging of the traction battery pack is determined by controlling the opening and closing of the first control switch K11 / K12 and the second control switch K21 / K22 according to the locomotive power supply mode and the state of charge of the traction battery pack. Specifically, this includes:

[0033] When the overhead contact line is powered and SOC q <SOC qmax At this time, first control switch K11 / K12 is closed, then control switch K21 / K22 is closed. The contact network sequentially charges the traction battery pack, supplies power to the control load and different loads connected to the bidirectional charger through the traction transformer, traction converter, auxiliary power supply device and bidirectional charger.

[0034] The first control switches K11 / K12 are manual switches. When the contact network is powered and SOC is reached... q <SOC qmax First, the first control switch K11 / K12 is closed, and the traction battery pack supplies power to the control load. The charger control equipment is powered on, enabling it to control the operation of the bidirectional charger. Then, the second control switch K21 / K22 is closed, and the bidirectional charger is powered on. The bidirectional charger converts the contact network power (380V) to 110V to charge the traction battery pack and supply power to the control load. On the other hand, it converts the contact network power (380V) to 220V, 24V, and 380V to supply power to different loads, including traction loads (such as traction motors) and auxiliary loads (such as lighting systems, cooling systems, etc.).

[0035] When the overhead contact line is powered and SOC q ≥SOC qmax At this time, first control switch K11 / K12 is closed, then control switch K21 / K22 is closed. The contact network supplies power to the control load and different loads connected to the bidirectional charger in sequence through traction transformer, traction converter, auxiliary power supply device, and bidirectional charger.

[0036] When the overhead contact line is powered and SOC q ≥SOC qmax At this time, there is no need to recharge the traction battery pack. Since the bidirectional charger converts the overhead contact line energy into a 110V output, and the traction battery pack outputs 110V, therefore, when the SOC (State of Charge) is reached... q ≥SOC qmax At that time, the bidirectional charger will no longer charge the traction battery pack.

[0037] When the traction battery pack is powered and SOC q ≥SOC qmin When the first control switch K11 / K12 is closed, the second control switch K21 / K22 is closed. The traction battery pack supplies power to the control load through the first control switch K11 / K12, and supplies power to different loads connected to the bidirectional charger through the second control switch K21 / K22 and the bidirectional charger.

[0038] When the overhead contact line is not powered (at which time the locomotive lowers its pantograph and the main circuit breaker is open), first control the first control switch K11 / K12 to close, so that the traction battery pack supplies power to the control load and the charger control equipment is powered on, enabling the charger control equipment to control the operation of the bidirectional charger. Then control the second control switch K21 / K22 to close, so that the bidirectional charger is powered on and the traction battery pack directly supplies power to the control load. The bidirectional charger converts the 110V output from the traction battery pack into 220V, 24V and 380V to supply power to different loads.

[0039] When the overhead contact line and traction battery pack are powered and SOC q ≥SOC qmin When the first control switch K11 / K12 is closed and the second control switch K21 / K22 is open, the traction battery pack supplies power to the control load through the first control switch K11 / K12. The contact network supplies power to different loads connected to the bidirectional charger through the traction transformer, traction converter, auxiliary power supply device, and bidirectional charger in sequence. That is, the traction battery supplies power to the control load, and the contact network supplies power to the traction load and auxiliary load.

[0040] In one specific embodiment of the present invention, the traction battery pack includes at least one individual battery cell, and the number of individual batteries in the traction battery pack can be determined according to the power required by the electric locomotive. Increasing the number of individual batteries and improving the battery voltage mode ensures that the traction battery pack meets the power requirements of the electric locomotive's application scenarios without causing cable overcurrent problems. For example, using multiple individual batteries connected in parallel can expand the capacity to meet the power supply needs during locomotive maintenance windows and for power supplies to vehicles in the depot; for ultra-high power (e.g., exceeding 80kW), it is also necessary to consider improving the battery voltage mode to avoid cable overcurrent problems caused by ultra-high power loads.

[0041] In this embodiment, the single battery is a power-type lithium titanate battery with a discharge power of 70kW and a battery output voltage of 110V (the output voltage adjustment range is (110-30%×110)V to (110+25%×110)V), which can realize the expansion of battery modules.

[0042] In one specific embodiment of the present invention, the second control switch K21 / K22 is a manual switch or a double-pole contactor. When both the first control switch K11 / K12 and the second control switch K21 / K22 are manual switches, the manual switch is a double-pole manual switch or two single-pole manual switches.

[0043] In one specific embodiment of the present invention, anti-reverse diodes D1 / D2 are connected in series between the traction battery pack and the first control switch K11 / K12.

[0044] This invention eliminates the control battery and its charger, adopting a traction battery + charger mode. In application scenarios such as self-propelled operation in areas without grids, during maintenance windows, power supply for in-depot vehicles, or power draw from control loads, the traction battery pack supplies power to the control load and different loads connected to the bidirectional charger. This solves the problem of limited application scenarios caused by the inability of the control battery to perform functions such as traction self-propelled operation and power supply during maintenance windows. It also optimizes the layout of the vehicle's equipment, reduces the number of devices, and improves the overall integration of the vehicle.

[0045] Example 2

[0046] This invention also provides a control method for an electric locomotive power supply system as described in Embodiment 1, comprising:

[0047] When the overhead contact line is powered and SOC q <SOC qmax At this time, first control switch K11 / K12 is closed, then control switch K21 / K22 is closed. The contact network sequentially charges the traction battery pack, supplies power to the control load and different loads connected to the bidirectional charger through the traction transformer, traction converter, auxiliary power supply device and bidirectional charger.

[0048] When the overhead contact line is powered and SOC q ≥SOC qmax At this time, first control switch K11 / K12 is closed, then control switch K21 / K22 is closed. The contact network supplies power to the control load and different loads connected to the bidirectional charger in sequence through traction transformer, traction converter, auxiliary power supply device, and bidirectional charger.

[0049] When the traction battery pack is powered and SOC q ≥SOC qmin When the first control switch K11 / K12 is closed, the second control switch K21 / K22 is closed. The traction battery pack supplies power to the control load through the first control switch K11 / K12, and supplies power to different loads connected to the bidirectional charger through the second control switch K21 / K22 and the bidirectional charger.

[0050] When the overhead contact line and traction battery pack are powered and SOC q ≥SOC qmin When the first control switch K11 / K12 is closed and the second control switch K21 / K22 is open, the traction battery pack supplies power to the control load through the first control switch K11 / K12. The contact network supplies power to different loads connected to the bidirectional charger through the traction transformer, traction converter, auxiliary power supply device, and bidirectional charger in sequence.

[0051] Among them, SOC qState of charge (SOC) of the traction battery pack qmax State of Charge (SOC) is the upper limit of normal charging and discharging of the traction battery pack. qmin This represents the lower limit of normal charging and discharging values ​​for the traction battery pack.

[0052] The above description only discloses specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or modifications that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A power supply system for an electric locomotive, comprising a contact network, a traction transformer, a traction converter, and an auxiliary power supply device connected in sequence, characterized in that: The power supply system also includes a traction battery pack, a first control switch, a bidirectional charger, and a second control switch; the traction battery pack is connected to a control load via the first control switch, which is a manual switch, and the control load includes a charger control device; the traction battery pack is also connected to the bidirectional charger via the second control switch, and the bidirectional charger is connected to the auxiliary power supply device and different loads; The power supply system is configured to control the opening and closing of the first and second control switches according to the locomotive power supply mode and the state of charge of the traction battery pack, specifically including: When the overhead contact system supplies power and the SOC q <SOC qmax , the first control switch is controlled to be closed first, and then the second control switch is controlled to be closed, and the overhead contact system sequentially passes through the traction transformer, the traction converter, the auxiliary power supply device, the bidirectional charger to charge the traction battery pack, to supply power to the control load and different loads connected with the bidirectional charger; When the overhead contact line is powered and SOC q ≥SOC qmax At this time, the first control switch is closed first, and then the second control switch is closed. The contact network supplies power to the control load and different loads connected to the bidirectional charger in sequence through the traction transformer, traction converter, auxiliary power supply device, and bidirectional charger. When the traction battery pack is powered and SOC q ≥SOC qmin At this time, first control switch is closed, then control switch is closed. Traction battery pack supplies power to control load through first control switch, and traction battery pack supplies power to different loads connected to bidirectional charger through second control switch and bidirectional charger. When the overhead contact line and traction battery pack are powered and SOC q ≥SOC qmin When the first control switch is closed and the second control switch is open, the traction battery pack supplies power to the control load through the first control switch. The contact network supplies power to different loads connected to the bidirectional charger through the traction transformer, traction converter, auxiliary power supply device, and bidirectional charger in sequence. Among them, SOC q State of charge (SOC) of the traction battery pack qmax State of Charge (SOC) is the upper limit of normal charging and discharging of the traction battery pack. qmin This represents the lower limit of normal charging and discharging values ​​for the traction battery pack.

2. The electric locomotive power supply system according to claim 1, characterized in that: The traction battery pack includes at least one individual battery cell.

3. The electric locomotive power supply system according to claim 2, characterized in that: The single-cell battery is a lithium titanate battery.

4. The electric locomotive power supply system according to claim 1, characterized in that: The second control switch is a manual switch or a double-pole contactor.

5. The electric locomotive power supply system according to claim 1 or 4, characterized in that: The manual switch is a double-pole manual switch or two single-pole manual switches.

6. The electric locomotive power supply system according to claim 1, characterized in that: An anti-reverse diode is connected in series between the traction battery pack and the first control switch.

7. The electric locomotive power supply system according to claim 1, characterized in that: The different loads connected to the bidirectional charger include traction loads and auxiliary loads.

8. An electric locomotive, characterized in that, The electric locomotive is equipped with a power supply system as described in any one of claims 1 to 7.

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