Brake system and brake control method of double-source locomotive and double-source locomotive

Abstract

The embodiment of the invention discloses a braking system of a double-source locomotive, a braking control method and the double-source locomotive. The braking system comprises a first braking subsystem, the first braking subsystem comprises a direct current isolation contactor, a braking resistor module, an uncontrolled rectifier module and a second alternating current contactor; when a fault of the motor side inverter is detected, the direct current isolation contactor is disconnected, the first alternating current contactor is disconnected, the second alternating current contactor is closed, alternating current of the permanent magnet traction motor is consumed by the brake resistor module after being rectified by the uncontrolled rectifier module, and braking of the double-source locomotive is completed. The technical problem that in the prior art, when a double-source locomotive runs on a long ramp, braking failure is caused by failure of a converter system, and then potential safety hazards exist is solved, and the technical effect of improving the running safety of the double-source locomotive is achieved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of brake control, and in particular to a brake system, a brake control method and a dual-source locomotive. Background Art

[0002] When operating on long and steep slopes, electric locomotives often use regenerative electric braking to convert kinetic energy into electrical energy and feed it back to the overhead catenary. However, in the event of grid failures, high grid voltage, or areas without a grid (such as non-electrified sections where dual-source locomotives operate), electrical energy cannot be fed back, forcing the locomotive to rely solely on air braking. Limited by the thermal load of the brake discs, air braking struggles to provide continuous and stable braking force, posing a safety hazard of locomotive stall or loss of control. This is particularly true in scenarios where dual-source locomotives frequently operate on long and continuous slopes, creating an urgent need for a safe and reliable low-constant-speed braking solution.

[0003] There are generally two solutions in the existing technology:

[0004] 1. Eddy current braking is used as a supplement to air braking, generating braking force through electromagnetic fields and consuming locomotive kinetic energy. However, eddy current braking relies on the intermediate DC power supply of the traction system and fails when the converter system fails. In addition, the eddy current braking device is heavy and energy-intensive, and the heat dissipation requirements increase maintenance costs. The braking force adjustment accuracy is low, making it difficult to adapt to complex slope conditions.

[0005] Second, energy storage devices (such as supercapacitors or power batteries) are used to absorb the electrical energy generated by regenerative braking, which is then stored and used for other locomotive power needs or for subsequent release. However, this method is complex to maintain, and the passive components are susceptible to temperature and aging, requiring regular maintenance, which increases operating costs. In addition, energy storage devices are expensive and bulky, increasing the weight and space occupied by the locomotive. A complex battery management system (BMS) is also required to ensure safety, limiting system reliability. Summary of the Invention

[0006] The embodiments of the present invention provide a braking system, a braking control method and a dual-source locomotive for a dual-source locomotive, which solve the technical problem in the prior art that when a dual-source locomotive is running on a long slope, the braking system fails due to failure of the inverter system, thereby posing a safety hazard.

[0007] In a first aspect, an embodiment of the present invention provides a braking system for a dual-source locomotive, wherein the power system of the dual-source locomotive includes a transformer, a grid-side converter, a motor-side inverter, a first AC contactor, and a permanent magnet traction motor; the primary side of the transformer is electrically connected to the grid, the secondary side of the transformer is electrically connected to the AC input of the grid-side converter, the DC output of the grid-side converter is electrically connected to the DC input of the motor-side inverter, and the AC output of the motor-side inverter is electrically connected to the permanent magnet traction motor via the first AC contactor;

[0008] The braking system includes a first braking subsystem; the first braking subsystem includes a DC isolation contactor, a braking resistor module, an uncontrolled rectifier module and a second AC contactor;

[0009] The AC input end of the uncontrolled rectifier module is electrically connected to the permanent magnet traction motor through the second AC contactor; the DC output end of the uncontrolled rectifier module is electrically connected to the braking resistor module; the braking resistor module is electrically connected to the DC output end of the grid-side converter through a DC isolation contactor;

[0010] When a fault in the motor-side inverter is detected, the DC isolation contactor is disconnected, the first AC contactor is disconnected, and the second AC contactor is closed. The AC power of the permanent magnet traction motor is rectified by the uncontrolled rectifier module and consumed by the braking resistor module to complete the braking of the dual-source locomotive.

[0011] Furthermore, the braking resistor module includes a braking resistor submodule and a braking chopper submodule;

[0012] The brake chopper submodule includes a diode and a first switch tube connected in series;

[0013] The braking resistor submodule is connected in parallel at both ends of the diode.

[0014] Furthermore, the braking resistor submodule includes a first braking resistor and a cooling fan;

[0015] The heat dissipation fan is arranged at the first brake resistor and is used to dissipate heat from the first brake resistor.

[0016] Furthermore, the DC isolation contactor includes a first switch and a second switch that are linked to each other, and the first switch and the second switch are respectively connected in series to the output lines on both sides of the grid-side converter.

[0017] In a second aspect, an embodiment of the present invention further provides a braking system for a dual-source locomotive, wherein the power system of the dual-source locomotive includes a transformer, a grid-side converter, a motor-side inverter, a first AC contactor, and a permanent magnet traction motor; the primary side of the transformer is electrically connected to the grid, the secondary side of the transformer is electrically connected to the AC input of the grid-side converter, the DC output of the grid-side converter is electrically connected to the DC input of the motor-side inverter, and the AC output of the motor-side inverter is electrically connected to the permanent magnet traction motor via the first AC contactor;

[0018] The braking system includes a second braking subsystem; the second braking subsystem includes at least two groups of braking resistor units;

[0019] The braking resistor units are connected in parallel, and the braking resistor units are electrically connected to the permanent magnet traction motor;

[0020] When the dual-source locomotive needs to brake, the first AC contactor is disconnected, and a set number of the braking resistor units are controlled to be connected to the permanent magnet traction motor. The AC power of the permanent magnet traction motor is consumed by the braking resistor unit to complete the braking of the dual-source locomotive.

[0021] Furthermore, each of the braking resistor units includes three second braking resistors and a third AC contactor;

[0022] The three second braking resistors are connected in a star connection or a delta connection, and are electrically connected to the three-phase AC line of the permanent magnet traction motor through the third AC contactor.

[0023] In a third aspect, an embodiment of the present invention further provides a braking control method for a dual-source locomotive, the braking control method being applied to the braking system of the dual-source locomotive described in the first aspect, the braking control method comprising:

[0024] If a converter system failure occurs in a dual-source locomotive, the DC isolation contactor is controlled to be disconnected, the first AC contactor is disconnected, and the second AC contactor is closed, so that the AC power of the permanent magnet traction motor is rectified by the uncontrolled rectifier module and consumed by the braking resistor module to complete the braking of the dual-source locomotive.

[0025] Furthermore, the braking control method further includes:

[0026] If the power grid fails or the vehicle is operating in a grid-free area, the DC isolation contactor is controlled to close, the first AC contactor is controlled to close, and the second AC contactor is controlled to open, so that the AC power of the permanent magnet traction motor is rectified by the motor-side inverter and consumed by the braking resistor module to complete the braking of the dual-source locomotive.

[0027] In a fourth aspect, an embodiment of the present invention further provides a braking control method for a dual-source locomotive, the braking control method being applied to the braking system of the dual-source locomotive described in the second aspect above, the braking control method comprising:

[0028] When the dual-source locomotive needs to brake, the first AC contactor is disconnected, and a set number of braking resistor units are controlled to be connected to the permanent magnet traction motor so that the AC power of the permanent magnet traction motor is consumed by the braking resistor units to complete the braking of the dual-source locomotive.

[0029] In a fifth aspect, an embodiment of the present invention further provides a dual-source locomotive, wherein the dual-source locomotive includes the braking system of the dual-source locomotive described in the first aspect, or the dual-source locomotive includes the braking system of the dual-source locomotive described in the second aspect.

[0030] The present invention discloses a braking system, a braking control method, and a dual-source locomotive. The braking system includes a first braking subsystem, the first braking subsystem including a DC isolation contactor, a braking resistor module, an uncontrolled rectifier module, and a second AC contactor. When a motor-side inverter fault is detected, the DC isolation contactor is disconnected, the first AC contactor is disconnected, and the second AC contactor is closed. The AC power of the permanent magnet traction motor is rectified by the uncontrolled rectifier module and consumed by the braking resistor module, thereby completing the braking of the dual-source locomotive. The present invention connects the braking system to the grid-side converter in the power system by providing a DC isolation contactor, and connects the uncontrolled rectifier module to the permanent magnet traction motor by providing a second AC contactor. When the converter system fails, the AC power generated by the permanent magnet traction motor can be rectified by the uncontrolled rectifier module and then consumed by the braking resistor module. This solves the technical problem in the prior art that when a dual-source locomotive is operating on a long slope, the failure of the converter system causes braking failure, thereby posing a safety hazard. This improves the operational safety of the dual-source locomotive. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a circuit diagram of a braking system for a dual-source locomotive provided by an embodiment of the present invention;

[0032] Figure 2 This is a circuit diagram of another dual-source locomotive braking system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0034] It should be noted that the terms "first," "second," and so on, in the specification, claims, and drawings of the present invention are used to distinguish different objects, and are not intended to limit a specific order. The following embodiments of the present invention can be implemented independently or in combination with each other, and the present invention does not impose specific limitations on this.

[0035] Those skilled in the art will understand that the power system of the dual-source locomotive in the present invention is a typical AC-DC-AC transmission system, wherein the grid-side converter is a four-quadrant converter for realizing energy exchange between the grid and the DC link of the power system, and the motor-side inverter is a traction inverter for driving a permanent magnet traction motor.

[0036] Figure 1 This is a circuit diagram of a braking system for a dual-source locomotive provided by an embodiment of the present invention.

[0037] like Figure 1 As shown, the power system 10 of the dual-source locomotive includes a transformer 1 (including a primary side 00 and a secondary side 01), a grid-side converter 2, a motor-side inverter 3, a first AC contactor 4 and a permanent magnet traction motor 5; the primary side 00 of the transformer 0 is electrically connected to the grid 20, the secondary side 01 of the transformer 0 is electrically connected to the AC input end of the grid-side converter 2, the DC output end of the grid-side converter 2 is electrically connected to the DC input end of the motor-side inverter 3, and the AC output end of the motor-side inverter 3 is electrically connected to the permanent magnet traction motor 5 through the first AC contactor 4.

[0038] The braking system includes a first braking subsystem 30; the first braking subsystem 30 includes a DC isolation contactor 6, a braking resistor module 7, an uncontrolled rectifier module 8 and a second AC contactor 9;

[0039] The AC input end of the uncontrolled rectifier module 8 is electrically connected to the permanent magnet traction motor 5 through the second AC contactor 9; the DC output end of the uncontrolled rectifier module 8 is electrically connected to the braking resistor module 7; the braking resistor module 7 is electrically connected to the DC output end of the grid-side converter 2 through the DC isolation contactor 6.

[0040] When a fault is detected in the motor-side inverter 3, the DC isolation contactor 6 is disconnected, the first AC contactor 4 is disconnected, and the second AC contactor 9 is closed. The AC power of the permanent magnet traction motor 5 is rectified by the uncontrolled rectifier module 8 and consumed by the braking resistor module 7, completing the braking of the dual-source locomotive.

[0041] Under normal operating conditions, the motor-side inverter 3 can rectify the three-phase AC power generated by the permanent magnet traction motor 5 into DC power. Both the first AC contactor 4 and the second AC contactor 9 are three-phase AC isolation contactors, used to control the connection between the permanent magnet traction motor 5 and the motor-side inverter 3 or the uncontrolled rectifier module 8. The permanent magnet traction motor 5 does not require external excitation and generates three-phase AC power during braking. The DC isolation contactor 6 controls the on / off switching of the DC circuit. The braking resistor module 7 consumes the feedback power from the permanent magnet traction motor 5, and its power capacity must match the output of the permanent magnet traction motor 5. The uncontrolled rectifier module 8 rectifies the three-phase AC power output by the permanent magnet traction motor 5 into DC power in the event of a power conversion system failure.

[0042] Specifically, the power grid 20 is usually 25kV, 50Hz high-voltage AC power. When the dual-source locomotive is in normal working condition, the high-voltage AC power of the power grid 20 is converted into low-voltage AC power through the transformer 1, and the low-voltage AC power is converted into DC power through the grid-side converter 2. The DC power is then converted into AC power through the motor-side inverter 3, and then sent to the permanent magnet traction motor 5 through the first AC contactor 4, so that the permanent magnet traction motor 5 rotates and drives the dual-source locomotive to travel.

[0043] When the dual-source locomotive needs to brake while traveling on a long slope, the permanent magnet traction motor 5 becomes a generator, converting the generated three-phase AC power into DC power through the motor-side inverter 3. The DC power is converted into AC power through the grid-side converter 2 and fed back to the power grid 20 through the transformer 1 to consume the AC power generated by the permanent magnet traction motor 5 and complete the braking of the dual-source locomotive.

[0044] However, when a fault is detected in the motor-side inverter 3, that is, when a fault occurs in the converter system of the dual-source locomotive, it is only necessary to control the DC isolation contactor 6 to be disconnected, the first AC contactor 4 to be disconnected, and the second AC contactor 9 to be closed. The AC power generated by the permanent magnet traction motor 5 is rectified by the uncontrolled rectifier module 8 and consumed by the braking resistor module 7 to complete the braking of the dual-source locomotive.

[0045] The present invention connects the braking system with the grid-side converter in the power system by setting a DC isolation contactor, and connects the uncontrolled rectifier module with the permanent magnet traction motor by setting a second AC contactor, so that when the converter system fails, the AC power generated by the permanent magnet traction motor can be rectified by the uncontrolled rectifier module and then enter the braking resistor module to be consumed. This solves the technical problem in the prior art that when a dual-source locomotive is running on a long slope, the brake failure is caused by the failure of the converter system, thereby posing a safety hazard, and achieves the technical effect of improving the operating safety of the dual-source locomotive.

[0046] Alternatively, as Figure 1 As shown, when it is detected that the power grid 20 fails or the grid-side converter 2 fails, but the motor-side inverter 3 operates normally, the DC isolation contactor 6 is controlled to close, the first AC contactor 4 is closed, and the second AC contactor 9 is disconnected, so that the AC power of the permanent magnet traction motor 5 is rectified by the motor-side inverter 3 and consumed by the braking resistor module 7, thereby completing the braking of the dual-source locomotive.

[0047] Alternatively, as Figure 1 As shown, the braking resistor module 7 includes a braking resistor submodule 71 and a braking chopper submodule 72; the braking chopper submodule 72 includes a diode and a first switch tube connected in series; the braking resistor submodule 71 is connected in parallel across the diode.

[0048] Alternatively, as Figure 1 As shown, the braking resistor submodule 71 includes a first braking resistor R1 and a cooling fan F; the cooling fan F is provided at the first braking resistor R1 for dissipating heat from the first braking resistor R1.

[0049] Specifically, the braking resistor submodule 71 can consume the feedback electric energy of the permanent magnet traction motor 5, and its power capacity needs to match the output of the permanent magnet traction motor 5; the braking chopper submodule 72 adopts PWM (Pulse Width Modulation) control, which can dynamically adjust the power consumption of the first braking resistor R1 in the braking resistor submodule 71.

[0050] Alternatively, as Figure 1 As described above, the DC isolation contactor 6 includes a first switch and a second switch that are linked to each other. The first switch and the second switch are respectively connected in series to the output lines on both sides of the grid-side converter 2 .

[0051] Figure 2 This is a circuit diagram of another dual-source locomotive braking system provided by an embodiment of the present invention.

[0052] like Figure 2 As shown, an embodiment of the present invention further provides a braking system for a dual-source locomotive, the power system of the dual-source locomotive includes a transformer 1, a grid-side converter 2, a motor-side inverter 3, a first AC contactor 4 and a permanent magnet traction motor 5; the primary side 00 of the transformer 0 is electrically connected to the grid 20, the secondary side 01 of the transformer 0 is electrically connected to the AC input end of the grid-side converter 2, the DC output end of the grid-side converter 2 is electrically connected to the DC input end of the motor-side inverter 3, and the AC output end of the motor-side inverter 3 is electrically connected to the permanent magnet traction motor 5 through the first AC contactor 4.

[0053] The braking system includes a second braking subsystem 40; the second braking subsystem 40 includes at least two groups of braking resistor units 41 ( Figure 2 , a schematic diagram of two groups of braking resistor units 41 is exemplarily given in FIG); each braking resistor unit 41 is connected in parallel, and the braking resistor unit 41 is electrically connected to the permanent magnet traction motor 5.

[0054] When the dual-source locomotive needs to brake, the first AC contactor 4 is disconnected, and a set number of braking resistor units 41 are controlled to be connected to the permanent magnet traction motor 5. The AC power of the permanent magnet traction motor 5 is consumed by the braking resistor unit 41, completing the braking of the dual-source locomotive.

[0055] Optionally, each braking resistor unit 41 includes three second braking resistors R and a third AC contactor K; the three second braking resistors R are connected in a star connection or a delta connection, and are electrically connected to the three-phase AC line of the permanent magnet traction motor 5 through the third AC contactor K.

[0056] Specifically, the second braking subsystem 40 is a multi-resistance braking system, which includes multiple braking resistor units 41. Each braking resistor unit 41 includes a three-phase AC contactor (i.e., the third AC contactor K mentioned above). When braking is required, whether the converter system fails, the power grid fails, or it operates in a grid-free area, the third AC contactor K can be controlled to close, and the second braking resistor R is connected to the permanent magnet traction motor 5 to consume the electric energy generated by the traction motor 5 to complete the braking of the dual-source locomotive.

[0057] It should be noted that, for the control of the second braking subsystem 40, the connection of resistors with different resistance values ​​can be achieved by controlling the third AC contactor K in the multiple braking resistor units 41. When a larger braking force or faster braking is required, a larger number of braking resistor units 41 are controlled to be connected. Conversely, a smaller number of braking resistor units 41 are controlled to be connected, so as to achieve precise control of the braking force.

[0058] The embodiment of the present invention also provides a braking control method for a dual-source locomotive, which is applied to Figure 1 The braking system of the dual-source locomotive shown in FIG. 1 , the braking control method specifically includes:

[0059] When a motor-side inverter fault is detected, the DC isolation contactor 6 is controlled to be disconnected, the first AC contactor 4 is disconnected, and the second AC contactor 9 is closed, so that the AC power of the permanent magnet traction motor 5 is rectified by the uncontrolled rectifier module 8 and consumed by the braking resistor module 7 to complete the braking of the dual-source locomotive.

[0060] For example, assuming that the current driving condition of the dual-source locomotive is a slope of 3%, the speed needs to be controlled at 15 km / h, but a fault is detected in the motor-side inverter 3, that is, the current dual-source locomotive has a converter system fault. At this time, the first AC contactor 4 and the DC isolation contactor 6 are controlled to be disconnected, and the second AC contactor 9 is closed. The AC power generated by the permanent magnet traction motor 5 is rectified into DC through the uncontrolled rectifier module 8, and the braking chopper submodule 72 adjusts the power of the braking resistor submodule 71 with a 30% duty cycle. Assuming that the resistance of the first braking resistor is 1.5Ω, the braking force output is 150 kN at this time, and the speed of the dual-source locomotive is stable at 15±1 km / h. The braking system can still operate independently in the event of a converter system failure, and has high fault tolerance.

[0061] Optionally, the braking control method also includes: when it is detected that the power grid 20 fails or the grid-side converter 2 fails, but the motor-side inverter 3 operates normally, controlling the DC isolation contactor 6 to close, the first AC contactor 4 to close, and the second AC contactor 9 to disconnect, so that the AC power of the permanent magnet traction motor 5 is rectified by the motor-side inverter 3 and consumed by the braking resistor module 7 to complete the braking of the dual-source locomotive.

[0062] Specifically, under normal circumstances, when a dual-source locomotive needs to brake while traveling on a long slope, in addition to normal air braking, it also needs to use the electric energy generated by the regenerative braking of the auxiliary energy storage device for braking, that is, the permanent magnet traction motor 5 becomes a generator, and the generated three-phase AC power is converted into DC power through the motor-side inverter 3, and the DC power is converted into AC power through the grid-side converter 2, and fed back to the power grid 20 through the transformer 1 to consume the AC power generated by the permanent magnet traction motor 5 and complete the braking of the dual-source locomotive.

[0063] However, the grid 20 already has a relatively high voltage of 25kV, and the capacity of the grid 20 is limited. The voltage fed back by the permanent magnet traction motor 5 cannot be received, and there is a situation where the grid 20 fails. Or, the dual-source locomotive is traveling in an off-grid area and cannot establish a connection with the grid 20. At this time, the electric energy cannot be fed back to the grid 20. Or, the grid-side converter 2 fails and cannot establish a connection with the grid 20. In this case, the DC isolation contactor 6 can be controlled to close, the first AC contactor 4 can be closed, and the second AC contactor 9 can be disconnected, so that the AC power of the permanent magnet traction motor 5 is rectified by the motor-side inverter 3, and then enters the braking resistor module 7 through the DC isolation contactor 6, and is then consumed by the braking resistor module 7 to complete the braking of the dual-source locomotive.

[0064] For example, assume a dual-source locomotive is operating in an off-grid area, on a 5% slope, and needs to maintain a speed of 20 km / h. At this point, the second AC contactor 9 needs to be opened, and the first AC contactor 4 and DC isolation contactor 6 need to be closed. The AC power generated by the permanent magnet traction motor 5 is rectified to DC by the motor-side inverter 3. The brake chopper submodule 72 adjusts the power consumption of the brake resistor submodule 71 with a 50% duty cycle. Assuming the resistance of the first brake resistor is 2Ω, the braking force output is stable at 200 kN. The dual-source locomotive maintains a speed of 20 ± 2 km / h, with a braking efficiency of 95%.

[0065] The braking control method for a dual-source locomotive provided in the embodiment of the present invention has the same technical features as the braking system for a dual-source locomotive provided in the above embodiment, and therefore can solve the same technical problems and achieve the same technical effects.

[0066] The embodiment of the present invention also provides a braking control method for a dual-source locomotive, which is applied to Figure 2 The braking system of the dual-source locomotive shown in FIG. 1 , the braking control method specifically includes:

[0067] When the dual-source locomotive needs to brake, the first AC contactor 4 is disconnected, and a set number of braking resistor units 41 are controlled to be connected to the permanent magnet traction motor 5, so that the AC power of the permanent magnet traction motor 5 is consumed by the braking resistor unit 41, completing the braking of the dual-source locomotive.

[0068] For example, assuming that the current driving condition of the dual-source locomotive is a slope change of 3%-6%, and the speed needs to be dynamically adjusted to 15-25km / h, then it is necessary to switch and connect multiple groups of second braking resistors R by controlling the on-off of the third AC contactor K in each braking resistor unit 41 according to the slope and speed requirements. It should be noted that the resistance values ​​of the second braking resistors R between different braking resistor units 41 can be the same or different. Assuming Figure 2 The second braking resistors R in the two braking resistor units 41 shown in the figure are 1Ω and 3Ω, respectively. At a 6% slope, the 1Ω resistor is selected, increasing the braking force to 250kN. At a 3% slope, the 3Ω resistor is switched, reducing the braking force to 120kN. Under this control method, the braking force of a dual-source locomotive is adjustable within a range of 100-300kN, adapting to a variety of operating conditions. Compared to traditional braking systems, this system improves control accuracy by 20%.

[0069] The braking control method for a dual-source locomotive provided in the embodiment of the present invention has the same technical features as the braking system for a dual-source locomotive provided in the above embodiment, and therefore can solve the same technical problems and achieve the same technical effects.

[0070] In summary, the braking control method provided by the embodiment of the present invention has the following beneficial effects: (1) Improved driving safety. When operating on long and steep slopes, the braking force stability is significantly improved, the speed control error is small, and the risk of loss of control is significantly reduced. (2) Improved fault adaptability. It supports grid failure and converter system failure scenarios, achieving extremely high system availability. (3) Controllable braking force. Multi-resistance resistor switching achieves a large braking force adjustment range, which can adapt to various slope and speed requirements. (4) High economy. Compared with traditional braking solutions, it effectively reduces system weight and reduces maintenance costs. (5) High braking efficiency. The permanent magnet traction motor does not require excitation, which effectively reduces braking energy consumption and reduces heat dissipation requirements.

[0071] The embodiment of the present invention further provides a dual-source locomotive, which includes the above-mentioned Figure 1 The braking system of the dual-source locomotive shown, or the dual-source locomotive includes the above-mentioned Figure 2 The braking system of the dual-source locomotive is shown.

[0072] The dual-source locomotive provided in the embodiment of the present invention includes the braking system of the dual-source locomotive in the above embodiment. Therefore, the dual-source locomotive provided in the embodiment of the present invention also has the beneficial effects described in the above embodiment, which will not be described in detail here.

[0073] In the description of the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0074] Finally, it should be noted that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A braking system for a dual-source locomotive, characterized in that: The power system of the dual-source locomotive includes a transformer, a grid-side converter, a motor-side inverter, a first AC contactor, and a permanent magnet traction motor; the primary side of the transformer is electrically connected to the grid, the secondary side of the transformer is electrically connected to the AC input terminal of the grid-side converter, the DC output terminal of the grid-side converter is electrically connected to the DC input terminal of the motor-side inverter, and the AC output terminal of the motor-side inverter is electrically connected to the permanent magnet traction motor through the first AC contactor; The braking system includes a first braking subsystem; the first braking subsystem includes a DC isolation contactor, a braking resistor module, an uncontrolled rectifier module and a second AC contactor; The AC input end of the uncontrolled rectifier module is electrically connected to the permanent magnet traction motor through the second AC contactor; the DC output end of the uncontrolled rectifier module is electrically connected to the braking resistor module; the braking resistor module is electrically connected to the DC output end of the grid-side converter through a DC isolation contactor; When a fault in the motor-side inverter is detected, the DC isolation contactor is disconnected, the first AC contactor is disconnected, and the second AC contactor is closed. The AC power of the permanent magnet traction motor is rectified by the uncontrolled rectifier module and consumed by the braking resistor module to complete the braking of the dual-source locomotive.

2. The braking system of a dual-source locomotive according to claim 1, characterized in that: The braking resistor module includes a braking resistor submodule and a braking chopper submodule; The brake chopper submodule includes a diode and a first switch tube connected in series; The braking resistor submodule is connected in parallel at both ends of the diode.

3. The braking system of a dual-source locomotive according to claim 2, characterized in that: The braking resistor submodule includes a first braking resistor and a cooling fan; The heat dissipation fan is arranged at the first brake resistor and is used to dissipate heat from the first brake resistor.

4. The braking system of a dual-source locomotive according to claim 1, characterized in that: The DC isolation contactor includes a first switch and a second switch that are linked to each other. The first switch and the second switch are respectively connected in series to the output lines on both sides of the grid-side converter.

5. A braking system for a dual-source locomotive, characterized in that: The power system of the dual-source locomotive includes a transformer, a grid-side converter, a motor-side inverter, a first AC contactor, and a permanent magnet traction motor; the primary side of the transformer is electrically connected to the grid, the secondary side of the transformer is electrically connected to the AC input terminal of the grid-side converter, the DC output terminal of the grid-side converter is electrically connected to the DC input terminal of the motor-side inverter, and the AC output terminal of the motor-side inverter is electrically connected to the permanent magnet traction motor through the first AC contactor; The braking system includes a second braking subsystem; the second braking subsystem includes at least two groups of braking resistor units; The braking resistor units are connected in parallel, and the braking resistor units are electrically connected to the permanent magnet traction motor; When the dual-source locomotive needs to brake, the first AC contactor is disconnected, and a set number of the braking resistor units are controlled to be connected to the permanent magnet traction motor. The AC power of the permanent magnet traction motor is consumed by the braking resistor unit to complete the braking of the dual-source locomotive.

6. The braking system of a dual-source locomotive according to claim 5, characterized in that: Each of the braking resistor units includes three second braking resistors and a third AC contactor; The three second braking resistors are connected in a star connection or a delta connection, and are electrically connected to the three-phase AC line of the permanent magnet traction motor through the third AC contactor.

7. A braking control method for a dual-source locomotive, characterized in that: The braking control method is applied to the braking system of the dual-source locomotive according to any one of claims 1 to 4, and the braking control method includes: When a motor-side inverter fault is detected, the DC isolation contactor is controlled to open, the first AC contactor is opened, and the second AC contactor is closed, so that the AC power of the permanent magnet traction motor is rectified by the uncontrolled rectifier module and consumed by the braking resistor module to complete the braking of the dual-source locomotive.

8. The braking control method for a dual-source locomotive according to claim 7, characterized in that: The braking control method further includes: When a grid failure or a grid-side converter fault is detected, but the motor-side inverter is operating normally, the DC isolation contactor is controlled to close, the first AC contactor is controlled to close, and the second AC contactor is controlled to open, so that the AC power of the permanent magnet traction motor is rectified by the motor-side inverter and consumed by the braking resistor module to complete the braking of the dual-source locomotive.

9. A braking control method for a dual-source locomotive, characterized in that: The braking control method is applied to the braking system of the dual-source locomotive according to any one of claims 5-6, and the braking control method includes: When the dual-source locomotive needs to brake, the first AC contactor is disconnected, and a set number of braking resistor units are controlled to be connected to the permanent magnet traction motor so that the AC power of the permanent magnet traction motor is consumed by the braking resistor units to complete the braking of the dual-source locomotive.

10. A dual-source locomotive, characterized in that: The dual-source locomotive includes the braking system of the dual-source locomotive according to any one of claims 1 to 4, or the dual-source locomotive includes the braking system of the dual-source locomotive according to any one of claims 5 to 6.

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