Hybrid internal combustion engine vehicle dc-to-dc power conversion module

Abstract

This invention discloses a DC-DC converter power module for hybrid internal combustion locomotives, relating to the control field of internal combustion locomotives. It adopts a modular structure integrating two independent bidirectional DC / DC chopper power units, integrating high-junction-temperature high-power IGBT devices, drive protection circuits, composite busbars, overvoltage absorption circuits, voltage equalization slow-release resistors, and high-efficiency lightweight water-cooled radiators. This module, applied to hybrid internal combustion locomotives, achieves a modular integrated design of two bidirectional DC / DC chopper units; solves the problems of large thickness, heavy weight, high cost, and low heat dissipation efficiency of water-cooled radiators; addresses the frame fixation strength issue; resolves the problem of high instantaneous heat flux density during power device startup easily causing burn-out; and solves the problem of insufficient output power under battery power source discharge conditions, simultaneously increasing discharge voltage and discharge current, thereby improving discharge power, increasing the proportion of power supplied by the power battery, and saving power supplied by the diesel engine.

Description

Technical Field

[0001] This invention relates to the field of control for internal combustion locomotives, specifically to a DC-DC power conversion module for hybrid internal combustion locomotives. Background Technology

[0002] Since energy conservation is a requirement and goal in almost all fields of modern development, the requirements for energy conservation indicators have also been raised in the fields of rail transit and urban rail transit. In terms of traction power sources, the hybrid power supply method of batteries and diesel engines is being vigorously developed, and the proportion of battery power supply is gradually increasing. At the same time, higher requirements are being placed on its heat dissipation capacity. In existing power modules, water cooling is used to achieve good heat dissipation, and most adopt a symmetrical double-sided heat dissipation structure. Power devices and accessories such as frames are symmetrically installed on both sides, with bolts fixed using the same threaded hole. However, this approach has the following drawbacks: problems frequently arise due to improper bolt use: when bolts are long, interference occurs between the bolt heads on both sides, resulting in inadequate device tightening and insufficient torque; when bolts are short, the tightening depth is insufficient, leading to unreliable device fixation. Alternatively, to meet the bolt tightening depth and ensure sufficient spacing between the bolt heads on both sides, the size of the water-cooled heatsink is appropriately increased. For example, to ensure the thickness for two bolts to be mounted, the cold plate needs to be 24mm thick, with the flow channel 6mm from the outer wall. However, this approach has the disadvantages: the thicker water-cooled heatsink not only increases weight and volume in terms of physical performance but also wastes materials and increases costs; in terms of heat transfer performance, it increases the heat conduction distance and thermal resistance, reducing heat dissipation efficiency. Therefore, improvements are needed in these areas. Alternatively, existing power units may use symmetrically mounted dual-sided power devices. The power loss of these dual-sided power devices is concentrated on the same cross-section of the radiator coolant flow channel. However, this concentrated heat dissipation results in excessively high instantaneous heat flux density during the power device startup mode, which is detrimental to maintaining the lifespan of the power devices and can easily lead to overheating and burnout. Furthermore, some existing power modules use three-level bidirectional DC / DC power modules with relatively low output power from their battery power source. The proportion of mild hybrid power supply is also low. This technology suffers from insufficient power supply from the DC / DC power module, with a discharge output power of only 90kW, which cannot meet the power supply requirements of more complex operating conditions. Moreover, existing DC / DC power modules have low power density, with each module containing only one power unit.

[0003] Therefore, in order to overcome the above problems, it is necessary to improve or redesign a new DC-DC power conversion module for hybrid internal combustion locomotives. Summary of the Invention

[0004] To address the problems of existing DC-DC converter power modules for hybrid internal combustion locomotives, such as large thickness, large size, high cost, low heat dissipation efficiency of water-cooled radiators, and insufficient output power under battery power source discharge conditions, this invention provides a DC-DC converter power module for hybrid internal combustion locomotives.

[0005] This invention is achieved through the following technical solution:

[0006] A DC-DC converter power module for a hybrid internal combustion engine vehicle includes a frame assembly, a water-cooling assembly, two sets of composite busbars and power devices; the water-cooling assembly includes a water-cooling substrate with water-cooling channels inside; the power devices include IGBT modules and slow-amplifier resistors; the frame assembly includes a left frame assembly and a right frame assembly.

[0007] Two sets of IGBT modules are mounted on the front of the left side wall of the water-cooled substrate. Each set of IGBT modules has a corresponding configuration board. Four sets of slow-release resistors are mounted on the rear of the left side wall of the water-cooled substrate. The left-side IGBT modules and the four sets of slow-release resistors are all bolted to the corresponding screw holes. An L-shaped insulating plate is installed between the slow-release resistors and the IGBT modules. The L-shaped insulating plate has fixing holes and cable tie holes. The L-shaped insulating plate is also bolted to the corresponding screw holes. Two sets of insulating support seats are connected to the front end of the water-cooled substrate. One set of composite busbars is located on the left side of the IGBT module. The outer side of the block is connected to the insulating support and the IGBT module on the left. The composite busbar on the left is electrically connected to the high voltage through the copper nut inside the insulating support. The outer wall of the composite busbar on the left is also provided with an absorption capacitor and a connection terminal for connecting the slow-release resistor. The absorption capacitor is used to reduce the peak voltage generated when the IGBT is turned off, and the slow-release resistor is used for voltage equalization and discharge protection. Two sets of IGBT modules are installed on the front of the right side wall of the water-cooled substrate. Each set of IGBT modules has a corresponding configuration board. Two sets of slow-release resistors are installed on the rear of the right side wall of the water-cooled substrate. The IGBT modules on the right side are connected to both sets of slow-release resistors. The IGBT module is bolted to the corresponding screw holes, and an L-shaped insulating plate is installed between the slow-release resistor and the IGBT module. The L-shaped insulating plate has fixing holes and cable tie holes. The L-shaped insulating plate is also bolted to the corresponding screw holes. Another composite busbar is located outside the right-side IGBT module and is connected to the insulating support and the right-side IGBT module. The right-side composite busbar is also electrically connected to the IGBT module via a copper nut inside the insulating support. An absorption capacitor and a connection terminal for the slow-release resistor are also provided on the outer wall of the right-side composite busbar. The left-side IGBT module, slow-release resistor, and L-shaped insulating plate are also connected to the IGBT module. The installation position of the L-shaped isolation insulation plate is parallel and offset from the installation positions of the IGBT module, slow-release resistor, and L-shaped isolation insulation plate on the right side. Therefore, the corresponding screw holes are also offset. The reason for setting the offset screw holes is to ensure that each bolt has its own independent threaded mounting hole, which ensures the tightening torque and avoids bolt interference. Moreover, after the components on both sides are installed in an alternating manner, the heating center points of the power devices will be spaced apart, avoiding a huge heat loss concentrated on the same cross section of the radiator coolant flow channel at the moment of vehicle start-up. This increases the safety of IGBT use, prevents overheating leading to aging and burnout, and improves IGBT lifespan.Since most components are symmetrically installed on the original water-cooled substrate, a certain tightening torque must be achieved when installing bolts. However, to ensure this torque, the thickness of the water-cooled substrate must be increased. Therefore, in this invention, the position of the screw holes is improved, and the bolts can be installed out of alignment, which can reduce the thickness of the radiator, i.e., the water-cooled substrate, making the distance between the radiator substrate and the internal coolant flow channel closer. For example, originally, to ensure sufficient thickness for two bolts to be installed opposite each other, the thickness of the water-cooled substrate was 24 mm, and the distance between the flow channel and the outer wall was 6 mm. After optimization, the thickness of the water-cooled substrate can be reduced to 18 mm, and the distance between the flow channel and the outer wall is 3 mm. This can significantly reduce the distance between the radiator substrate and the internal coolant flow channel, reduce the heat conduction distance and thermal resistance, improve the heat dissipation efficiency, and at the same time make the material cost lower and the product weight lighter.

[0008] The left frame assembly is located outside the left composite busbar. The left frame assembly includes an integrally formed upper heat dissipation plate I, an intermediate mounting plate I, and a lower heat dissipation plate I. The upper heat dissipation plate I, the intermediate mounting plate I, and the lower heat dissipation plate I are in an inverted U shape. The upper heat dissipation plate I and the lower heat dissipation plate I each have a plurality of heat dissipation and observation windows. The edges of the upper heat dissipation plate I and the lower heat dissipation plate I are bent inward, and a plurality of connection ends for connecting to the water-cooled substrate are provided on both the front and rear sides. The connection ends are connected to the corresponding frame mounting holes on the water-cooled substrate. Two sets of drive board assemblies that are used in matching with the IGBT module on the left side are also provided and are installed on the outer wall of the intermediate mounting plate I. Four terminal blocks are also installed at the lower part in front of the intermediate mounting plate I; a cover plate is further provided outside the left drive board assembly. The cover plate is in an inverted U shape. The edges of the upper and lower parts of the cover plate are bent outward, and the bent parts are connected to the intermediate mounting plate I by bolts. A window is also opened in each of the upper and lower parts of the cover plate. A dust-proof baffle is fixedly provided at the rear side of the cover plate; the right frame assembly is located outside the right composite busbar. The right frame assembly includes an integrally formed upper heat dissipation plate II, an intermediate mounting plate II, and a lower heat dissipation plate II. The upper heat dissipation plate II, the intermediate mounting plate II, and the lower heat dissipation plate II are in an inverted U shape. The upper heat dissipation plate II and the lower heat dissipation plate II each have a plurality of heat dissipation and observation windows. The edges of the upper heat dissipation plate II and the lower heat dissipation plate II are bent inward, and a plurality of connection ends for connecting to the water-cooled substrate are provided on both the front and rear sides. The connection ends are connected to the corresponding frame mounting holes on the water-cooled substrate. Two sets of drive board assemblies that are used in matching with the IGBT module on the right side are also provided and are installed on the outer wall of the intermediate mounting plate II; a cover plate is further provided outside the right drive board assembly. The structure of the cover plate is opposite and symmetric to the structure of the left cover plate; the frame mounting holes of the left frame assembly installed on the water-cooled substrate and the frame mounting holes of the right frame assembly installed on the water-cooled substrate are misaligned with each other, so that their respective connection ends are also misaligned; the purpose of setting the misaligned frame mounting holes at this time is also because it needs to correspond to the components installed with bilateral misalignment and needs to be matched with them. However, it is necessary to ensure that the positions of the two frame assemblies relative to the positions to be installed remain unchanged, so that the overall structure remains unchanged.

[0009] The rear end of the water-cooled substrate is connected to two guide posts for positioning during the assembly of the power module and the converter. The rear side of the water-cooled substrate is also provided with a water inlet and a water outlet, with the water inlet located at the bottom and the water outlet located at the top. The interior of the water-cooled substrate is configured with flow channels according to the positions of the IGBT module and the slow-release resistor, and the flow channels are M-shaped. The composite busbars on the left and right sides are each provided with 5 external high-voltage electrical interfaces.

[0010] To achieve the goal of reducing the thickness of the water-cooled substrate, the improvement made to the original power module in this invention is as follows:

[0011] Step 1: Reduce the thickness of the heatsink. Lower material costs and lighter product weight mean the heatsink base plate is closer to the internal coolant channels, reducing heat conduction distance and thermal resistance, and improving heat dissipation efficiency.

[0012] Step 2: Add staggered mounting holes to the radiator. Keeping the positions of the threaded holes on the first side of the water-cooled radiator unchanged, simultaneously shift the positions of the original threaded holes on the second side a certain distance towards the rear end of the radiator (towards the inlet and outlet). This means that all the threaded mounting holes on this side are spaced a certain distance from all the threaded mounting holes on the first side. Install all components on both sides in a staggered manner, ensuring that each bolt has its own independent threaded mounting hole. This guarantees tightening torque while preventing bolt interference. After staggering the components on both sides, the heat dissipation centers of the power devices will be spaced out, preventing a large heat loss from concentrated on the same cross-section of the radiator coolant flow channel at the moment of vehicle startup. This increases the safety of IGBT operation, prevents overheating leading to aging and burnout, and extends IGBT lifespan.

[0013] Step 3: Modify the mounting feet and fixing holes of the second side frame. After the components on both sides are installed in an alternating manner, the mounting hole position of the first side frame (left frame) remains unchanged, so there is no need to modify the left frame at this time; the mounting hole position of the second side frame (right frame) is moved back a certain distance, and matches the distance moved in the previous step. At this time, the two frames are no longer aligned in appearance, so it is necessary to modify the cutting position of the right frame, and move the size of the fixing feet and fixing holes of the right frame a certain distance towards the front end of the radiator (in the opposite direction of the inlet and outlet) to ensure that the right frame remains unchanged relative to the original installation position of the radiator, that is, the overall structural appearance remains unchanged.

[0014] Furthermore, the power devices on the left side of the water-cooled substrate are arranged as follows: one IGBT module is arranged at the top and one at the bottom, namely T1 and T2. The slow-amplifier resistors are divided into two rows. The upper left row has a slow-amplifier resistor CDR3 or CDR9 on the power battery side, and the upper right row has a slow-amplifier resistor CDR1 or CDR7 on the middle DC bus side. The lower left row has a slow-amplifier resistor CDR6 or CDR12 on the power battery side, and the lower right row has a slow-amplifier resistor CDR2 or CDR8 on the middle DC bus side. There are also two absorption capacitors C1 and C2. The power devices on the right side of the water-cooled substrate are arranged as follows: one IGBT module is arranged at the top and one at the bottom, namely T4 and T3. The slow-amplifier resistors are divided into two rows. Two rows: the upper row has a slow-release resistor CDR5 or CDR11 on the middle DC bus side, and the lower row has a slow-release resistor CDR4 or CDR10 on the middle DC bus side, along with two absorption capacitors C3 and C4. The full-bridge IGBTs formed by T1 and T2, and the full-bridge IGBTs formed by T4 and T3 are electrically connected at high voltage through a composite busbar. One end of each of the two slow-release resistors on the middle DC bus side is connected to the auxiliary terminals of the composite busbar's DC+ and DC- terminals, and the other end is shorted through a copper busbar and connected to the auxiliary terminal of the middle M terminal of the composite busbar. The two slow-release resistors on the power battery side are fixed to the power module terminal block through four high-voltage wire harnesses and connected to the corresponding wire harnesses in the converter cabinet.

[0015] Preferably, the cover plate is semi-transparent.

[0016] Preferably, the heat dissipation and observation window is circular.

[0017] This invention installs DC-DC power conversion modules in the converter cabinet of a hybrid diesel shunting locomotive. The entire locomotive adopts a frame control mode. Each locomotive contains one traction auxiliary converter cabinet, which is equipped with two DC-DC power conversion modules. Each DC-DC power conversion module contains two sets of DC-DC power conversion units.

[0018] The traction auxiliary converter cabinet includes the traction converter system, auxiliary converter system, and traction charger system. The traction converter system is powered by a diesel generator and traction charger, converting three-phase AC 620V~1406V voltage to DC 800V~1800V via AC-DC conversion to power the traction system, auxiliary system, and traction charger system. The intermediate bus voltage is converted to AC 0V~1404V three-phase AC power via DC-AC conversion to drive the traction motor. The auxiliary converter system shares an intermediate DC bus with the traction converter system. Through a DC-AC-DC converter, it transforms DC 800V-1800V to DC 600V, and then converts DC 600V to AC 380V three-phase AC power to supply auxiliary loads such as cooling fans, traction fans, air compressors, and air conditioners. Simultaneously, the 110V charger draws power from the DC 600V DC bus, transforming DC 600V to DC 110V to power loads such as the battery, oil pump, and fuel pump. The traction charger system includes four sets of traction chargers, realizing the charging and discharging functions of the vehicle's power battery. During charging, it converts the intermediate DC bus voltage (DC 1200V-1800V) to DC 1020V-1500V to charge the power battery. During discharging, the traction charger converts the power battery voltage (DC 1020V-1500V) to DC 1500V-1800V for use by the traction auxiliary system.

[0019] The traction auxiliary converter cabinet's traction charger system includes four sets of traction chargers. Each of the four traction charger power units is integrated in pairs onto a DC-DC converter power module. Each DC-DC converter power module contains two charger power units and operates in a three-level mode, enabling bidirectional DC / DC conversion. The vehicle's traction auxiliary converter cabinet supplies power to the traction motor through three-phase rectification (AC-DC) and three-phase inversion (DC-AC) circuits. The traction charger system achieves bidirectional DC / DC chopping functionality through the shared power supply mode of the three-phase rectified DC bus and the power battery, as well as the charging and discharging functions of the power battery. During battery charging, it operates in DC / DC buck chopping mode, with energy flowing from left to right; during battery discharging, it operates in DC / DC boost chopping mode, with energy flowing from right to left. The composite busbar has 10 interfaces, designated S1, S2…S10; located in a water-cooled… The components on the left side of the substrate are S1~S5, and those on the right side of the water-cooled substrate are S6~S10. S1, S2, S3, S6, S7, and S8 are the high-voltage DC input interfaces of the power module. S1 and S6 are connected to the DC+ of the DC 1200V~1800V DC bus, and S3 and S8 are connected to the DC- of the DC 1200V~1800V DC bus. S3 and S7 are connected to point M. S4, S5, S9, and S10 are the high-voltage DC output interfaces, all connected to the outside via a composite busbar. S4 is connected to P1, S5 to N1, S9 to P2, and S10 to N2. The power module connects the required +15V power supply to the charger control unit through two 6-pin low-voltage connectors. The wiring harness uses 2*0.5mm² twisted-pair shielded cables, and the control unit input shielded cable is connected to the power module frame. The two 6-pin low-voltage connectors for the power signal are designated as X1 and X2. The circuit diagrams of each charger power unit are as follows:

[0020] 1) Within the first DC-DC power conversion module, the first set of charger power units includes two full-bridge IGBTs. The upper and lower bridge arms of the two full-bridge IGBTs are defined as T1H, T1B, T2H, and T2B, respectively. The circuit principle is as follows: T1H and T1B are controlled to be turned on and off by the DBT1 driver board. A T1 configuration board for protection is provided between T1H and T1B and the DBT1 driver board. The DBT1 driver board is powered by a connector. A filter capacitor C1 is connected in parallel across the two ends of the series connection between T1H and T1B, and it is also connected in parallel with a slow-amplifier resistor CDR1. The two ends of T2H and T2B are connected between S1 and S2 of the composite busbar, with S2 connected to point M. T2H and T2B are controlled to be turned on and off by the DBT2 driver board. A T2 configuration board for protection is provided between T2H and T2B and the DBT2 driver board. The DBT2 driver board is powered by a connector. The two ends of T2H and T2B connected in series are connected in parallel with a filter capacitor C2, and also in parallel with a slow-release resistor CDR2. The two ends of CDR2 are connected between S2 and S3 of the composite busbar. The slow-release resistor CDR3 is connected in parallel between S11 and S12 on the power battery side through a terminal block.

[0021] The second set of charger power units includes two full-bridge IGBTs. The upper and lower bridge arms of the two full-bridge IGBTs are defined as T3H, T3B, T4H, and T4B, respectively. The circuit principle is as follows: T3H and T3B are controlled to be turned on and off by the DBT3 driver board. A T3 configuration board for protection is provided between T3H and T3B and the DBT3 driver board. The DBT3 driver board is powered by a connector. The two ends of T3H and T3B connected in series are connected in parallel with a filter capacitor C3, and also in parallel with a slow-amplification resistor CDR4. The two ends of CDR4 are connected to a complex circuit. Between S6 and S7 of the composite busbar, S7 is connected to point M; T4H and T4B are controlled to be turned on and off by the DBT4 driver board. A T4 configuration board for protection is provided between T4H and T4B and the DBT4 driver board. The DBT4 driver board is powered by a connector; the two ends of T4H and T4B connected in series are connected in parallel with a filter capacitor C4, and also in parallel with a slow-release resistor CDR5; the two ends of CDR5 are connected between S7 and S8 of the composite busbar; the slow-release resistor CDR6 is connected in parallel between S13 and S14 on the power battery side through a terminal block.

[0022] 2) Within the second DC-DC power module, the first set of charger power units includes two full-bridge IGBTs. The upper and lower arms of the two full-bridge IGBTs are defined as T1H, T1B, T2H, and T2B, respectively. The circuit principle is as follows: T1H and T1B are controlled to be turned on and off by the DBT1 driver board. A T1 configuration board for protection is provided between T1H and T1B and the DBT1 driver board. The DBT1 driver board is powered by a connector. A filter capacitor C1 is connected in parallel across the two ends of T1H and T1B after they are connected in series, and it is also connected in parallel with a slow-amplifier resistor CDR7. The two ends of T2H and T2B are connected between S1 and S2 of the composite busbar, with S2 connected to point M. T2H and T2B are controlled to be turned on and off by the DBT2 driver board. A T2 configuration board for protection is provided between T2H and T2B and the DBT2 driver board. The DBT2 driver board is powered by a connector. The two ends of T2H and T2B connected in series are connected in parallel with a filter capacitor C2, and also in parallel with a slow-release resistor CDR8. The two ends of CDR8 are connected between S2 and S3 of the composite busbar. The slow-release resistor CDR9 is connected in parallel between S11 and S12 on the power battery side through a terminal block.

[0023] The second set of charger power units includes two full-bridge IGBTs. The upper and lower bridge arms of the two full-bridge IGBTs are defined as T3H, T3B, T4H, and T4B, respectively. The circuit principle is as follows: T3H and T3B are controlled to be turned on and off by the DBT3 driver board. A T3 configuration board for protection is provided between T3H and T3B and the DBT3 driver board. The DBT3 driver board is powered by a connector. The two ends of T3H and T3B connected in series are connected in parallel with a filter capacitor C3, and also in parallel with a slow-amplification resistor CDR10. The two ends of CDR10 are connected to a composite... Between S6 and S7 of the busbar, S7 is connected to point M; T4H and T4B are controlled to be turned on and off by the DBT4 driver board. A T4 configuration board for protection is provided between T4H and T4B and the DBT4 driver board. The DBT4 driver board is powered by a connector; the two ends of T4H and T4B connected in series are connected in parallel with a filter capacitor C4, and also in parallel with a slow-release resistor CDR11; the two ends of CDR11 are connected between S7 and S8 of the composite busbar; the slow-release resistor CDR12 is connected in parallel between S13 and S14 on the power battery side through a terminal block.

[0024] The charging method for the DC-DC converter power module of the hybrid internal combustion locomotive described above involves the charger power unit drawing power from the intermediate DC bus (DC1200V-DC1800V). Taking T1H and T2B as examples, T1H and T2B are alternately turned on at 180° intervals, with equal duty cycles, both greater than 50%. At any given time, at least one switch of T1H and T2B is turned on, and there are also cases where T1H and T2B are turned on simultaneously. When T1H and T2B are turned on simultaneously, the front-end voltage of the output filter reactors CL1, CL2, CL3, and CL4 is 1800V. When T1H and T2B are turned on simultaneously, the voltage at the front end of the output filter reactors CL1, CL2, CL3, and CL4 is 1800V. When one of T2B is turned on, the front-end voltage of the output filter reactors CL1, CL2, CL3, and CL4 is 900V. Therefore, the voltage at the front end of the reactors is a pulse wave alternating between 900V and 1800V. After output LC filtering, the output voltage is filtered to the required DC1020V-DC1500V. The magnitude of the output voltage and current is adjusted by adjusting the duty cycle of T1H and T2B. During operation, the anti-parallel diode of T2H works in conjunction with the IGBT of T1H to conduct, and the anti-parallel diode of T1B works in conjunction with the IGBT of T2B to conduct, alternately charging the power battery side.

[0025] The above-mentioned discharge method for the DC-DC converter power module of a hybrid internal combustion engine vehicle involves the following steps: In discharge mode, the charger power module draws power from the power battery and charges the filter capacitors CFC3, CFC6, CFC9, and CFC12 of the four units through a pre-charging circuit. The filter capacitors act as energy storage inductors and are boosted through a three-level circuit. T2 and T3 are turned on alternately by 180° with equal duty cycles, and both duty cycles are less than 50%. Then, the voltage is stabilized at DC1200V-DC1800V through a supporting capacitor. The output voltage and current are adjusted by adjusting the duty cycles of T2 and T3. During operation, the anti-parallel diode of T4 is turned on in conjunction with the conduction of T2, and the anti-parallel diode of T1 is turned on in conjunction with the conduction of the IGBT of T3, which alternately discharge to the DC bus side.

[0026] Compared with existing technologies, the present invention has the following beneficial effects: The DC-DC converter power module for hybrid internal combustion locomotives provided by the present invention adopts a modular structure integrating two independent bidirectional DC / DC chopper power units. It integrates high-junction-temperature high-power devices such as IGBTs, drive protection circuits, composite busbars, overvoltage absorption circuits, voltage equalization slow-release resistors, and high-efficiency lightweight water-cooled radiators. This module, applied to hybrid internal combustion locomotives, realizes the modular integrated design of two bidirectional DC / DC chopper units; solves the problems of large thickness, heavy weight, high cost, and low heat dissipation efficiency of water-cooled radiators; improves the heat dissipation efficiency of water-cooled radiators; solves the problem of frame fixing strength, increasing product reliability; solves the problem of high instantaneous heat flux density of power devices during startup, which can easily cause burn-out; solves the problem of inadequate tightening caused by bolts on devices and frames; and solves the problem of insufficient output power during battery power source discharge, simultaneously increasing discharge voltage and discharge current, thereby increasing discharge power, increasing the proportion of power supplied by the power battery, saving diesel engine power, and contributing to the achievement of the "dual-carbon" target. Attached Figure Description

[0027] Figure 1 This is an overall structural diagram of the power module of the present invention.

[0028] Figure 2 This is an exploded view of the power module of the present invention.

[0029] Figure 3 This is a layout diagram of the power devices on the left side of the water-cooled substrate of the power module of the present invention.

[0030] Figure 4 This is a layout diagram of the power devices on the right side of the water-cooled substrate of the power module of the present invention.

[0031] Figure 5 This is a flow channel diagram of the water-cooled substrate of the power module of the present invention.

[0032] Figure 6 This is a schematic diagram of the external electrical interface of the power module of the present invention.

[0033] Figure 7 This is the topology diagram of the main circuit of the traction auxiliary converter cabinet.

[0034] Figure 8 This is the main circuit topology diagram of the traction charger system.

[0035] Figure 9 This is the main circuit topology diagram of the DC-DC power conversion module.

[0036] Figure 10 The diagram shows the operation of the traction charger power unit charging mode one, as indicated by the thick gray lines.

[0037] Figure 11 The diagram shows the operation of the second charging mode for the traction charger power unit, as indicated by the thick gray lines.

[0038] Figure 12 The diagram shows the operation of the traction charger power unit in charging mode three, as indicated by the thick gray lines.

[0039] Figure 13 This is a schematic diagram of the operation of the traction charger power unit in discharge mode one, as shown by the thick gray lines.

[0040] Figure 14 This is a schematic diagram of the operation of the traction charger power unit in discharge mode two, as shown by the thick gray lines.

[0041] Figure 15 The overall control block diagram for the hybrid power supply control method of diesel engine and power battery.

[0042] Figure 16 This is a flowchart illustrating the traction mode switching process between the diesel engine and the power battery.

[0043] The diagram is labeled as follows: 1-IGBT module, 2-configuration board, 3-water-cooled substrate, 4-slow-release resistor, 5-insulating support, 6-drive board assembly, 7-absorption capacitor, 8-composite busbar, 9-left frame assembly, 10-right frame assembly, 11-terminal block, 12-cover plate, 13-guide post, 14-L-shaped insulating plate, 15-heat dissipation and observation window, 301-water inlet, 302-water outlet, 303-frame mounting hole, 901-upper heat sink I, 902-middle mounting plate I, 903-lower heat sink I, 1001-upper heat sink II, 1002-middle mounting plate II, 1003-lower heat sink II. Detailed Implementation

[0044] The present invention will be further described below with reference to specific embodiments.

[0045] A DC-DC power conversion module for hybrid internal combustion locomotives, such as Figure 1 and Figure 2The system includes a frame assembly, a water-cooling assembly, two sets of composite busbars 8, and power devices. The water-cooling assembly includes a water-cooled substrate 3 with water-cooling channels inside. The power devices include IGBT modules 1 and slow-amplification resistors 4. The frame assembly includes a left frame assembly 9 and a right frame assembly 10. Two sets of IGBT modules 1 are mounted on the front of the left side wall of the water-cooled substrate 3, each set of IGBT modules 1 having a corresponding configuration board 2. Four sets of slow-amplification resistors 4 are mounted on the rear of the left side wall of the water-cooled substrate 3. The left-side IGBT modules 1 and the four sets of slow-amplification resistors 4 are all bolted together. On the corresponding screw holes, and between the slow-release resistor 4 and the IGBT module 1, an L-shaped insulating plate 14 is installed, and the L-shaped insulating plate 14 is provided with fixing holes and cable tie holes. The L-shaped insulating plate 14 is also installed on the corresponding screw holes by bolt connection. The front end of the water-cooled substrate 3 is connected to two sets of insulating support seats 5, one of which is a composite busbar 8 located on the left side of the left IGBT module 1 and connected to the insulating support seat 5 and the left IGBT module 1. The left composite busbar 8 is electrically connected to the high voltage through the copper nut inside the insulating support seat 5. The outer wall of the left composite busbar 8 is also provided with The absorption capacitor 7 and the connection terminals for the slow-release resistor 4 are included. Two sets of IGBT modules 1 are installed on the front of the right side wall of the water-cooled substrate 3, each set of IGBT modules 1 having a corresponding configuration plate 2. Two sets of slow-release resistors 4 are installed on the rear of the right side wall of the water-cooled substrate 3. The IGBT modules 1 on the right side and the two sets of slow-release resistors 4 are all bolted to the corresponding screw holes. An L-shaped insulating plate 14 is installed between the slow-release resistor 4 and the IGBT module 1, and the L-shaped insulating plate 14 has fixing holes and cable tie holes. The L-shaped insulating plate 14 is also bolted to the corresponding... On the screw holes, another set of composite busbars 8 is located to the right of the right IGBT module 1 and is connected to the insulating support base 5 and the right IGBT module 1. The right composite busbar 8 is also connected to the high voltage through the copper nut inside the insulating support base 5. The outer wall of the right composite busbar 8 is also provided with an absorption capacitor 7 and a connection terminal for connecting the slow-release resistor. The installation positions of the left IGBT module 1, slow-release resistor 4 and L-shaped isolation insulating plate 14 are parallel and offset from the installation positions of the right IGBT module 1, slow-release resistor 4 and L-shaped isolation insulating plate 14, so the screw holes for installation are also offset accordingly.The left frame assembly 9 is located outside the left composite busbar 8. The left frame assembly 9 includes an integrally formed upper heat sink I 901, a middle mounting plate I 902, and a lower heat sink I 903. The upper heat sink I 901, the middle mounting plate I 902, and the lower heat sink I 903 are in the shape of a "U". The upper heat sink I 901 and the lower heat sink I 903 each have multiple heat dissipation and observation windows 15. The edges of the upper heat sink I 901 and the lower heat sink I 903 are bent inward, and multiple connection ends for connecting to the water-cooled substrate 3 are provided on the front and rear sides. The connection ends are connected to the corresponding frame mounting holes 303 on the water-cooled substrate 3. The drive board assembly is matched with the IGBT module 1 on the left. Component 6 is also provided in two sets and installed on the outer wall of the intermediate mounting plate I 902. A row of four terminal blocks 11 is also installed on the lower front part of the intermediate mounting plate I 902. A cover plate 12 is also provided on the outer side of the left drive plate assembly 6. The cover plate 12 is "U" shaped. The upper and lower edges of the cover plate 12 are bent outward and the bent parts are connected to the intermediate mounting plate I 902 by bolts. There is a window on the upper and lower parts of the cover plate 12. A dustproof baffle is also fixed on the rear side of the cover plate 12. The right frame assembly 10 is located outside the right composite busbar 8. The right frame assembly 10 includes an integrally formed upper heat sink II 1001, an intermediate mounting plate II 1002 and a lower heat sink. II1003, the upper heat sink II1001, the middle mounting plate II1002, and the lower heat sink II1003 are in the shape of a "U". The upper heat sink II1001 and the lower heat sink II1003 each have multiple heat dissipation and observation windows 15. The edges of the upper heat sink II1001 and the lower heat sink II1003 are bent inwards, and multiple connection ends for connection to the water-cooled substrate 3 are provided on both the front and rear sides. The connection ends are connected to the corresponding frame mounting holes 303 on the water-cooled substrate 3. Two sets of drive board assemblies 6, which are matched with the IGBT module 1 on the right side, are also provided and installed on the outer wall of the middle mounting plate II1002. A cover plate 12 is also provided on the outer side of the right drive board assembly 6. The structure 12 is opposite and symmetrical to the left cover plate 12; the frame mounting holes 303 of the left frame assembly 9 and the frame mounting holes 303 of the right frame assembly 10 on the water-cooled substrate 3 are staggered, so that their respective connection ends are also staggered; the rear end of the water-cooled substrate 3 is connected to two guide pillars 13, and the rear side of the water-cooled substrate 3 is also provided with a water inlet 301 and a water outlet 302, with the water inlet 302 located at the bottom and the water outlet 301 located at the top. The internal flow channel of the water-cooled substrate 3 is set according to the position of the IGBT module 1 and the slow-release resistor 4, and the flow channel is M-shaped; the composite busbars 8 on the left and right sides are each provided with 5 external high-voltage electrical interfaces, such as; Figure 6 As shown.

[0046] In this embodiment, as Figure 3 and Figure 4As shown, the power devices on the left side of the water-cooled substrate 3 are arranged as follows: IGBT modules 1 are arranged one at the top and one at the bottom, namely T1 and T2; the slow-amplifier resistors 4 are arranged in two rows, with the upper left row having a slow-amplifier resistor CDR3 or CDR9 on the power battery side, and the upper right row having a slow-amplifier resistor CDR1 or CDR7 on the middle DC bus side; the lower left row has a slow-amplifier resistor CDR6 or CDR12 on the power battery side, and the lower right row has a slow-amplifier resistor CDR2 or CDR8 on the middle DC bus side; and two absorption capacitors C1 and C2. The power devices on the right side of the water-cooled substrate 3 are arranged as follows: IGBT modules 1 are arranged one at the top and one at the bottom, namely T4 and T3; the slow-amplifier resistors 4 are arranged in two rows. Divided into two rows, the upper row has a slow-release resistor CDR5 or CDR11 on the middle DC bus side, and the lower row has a slow-release resistor CDR4 or CDR10 on the middle DC bus side, along with two absorption capacitors C3 and C4. The full-bridge IGBTs formed by T1 and T2, and the full-bridge IGBTs formed by T4 and T3 are connected by high-voltage electrical connection through the composite busbar. One end of each of the two slow-release resistors on the middle DC bus side is connected to the auxiliary terminals of the composite busbar's DC+ and DC-, and the other end is shorted through a copper busbar and connected to the auxiliary terminal of the middle M terminal of the composite busbar. The two slow-release resistors on the power battery side are fixed to the power module terminal block through four high-voltage wire harnesses and connected to the corresponding wire harnesses in the converter cabinet.

[0047] In this embodiment, the following preferred technical solution is also adopted: the cover plate 12 is semi-transparent; the heat dissipation and observation window 15 is circular.

[0048] The aforementioned DC-DC power conversion module is applied in a traction charger system, such as... Figure 7 and Figure 8As shown, the system includes four traction chargers to charge and discharge the vehicle's power battery. Each of the four traction charger power units is integrated in pairs onto a DC-DC converter module. Each DC-DC converter module contains two charger power units and operates in a three-level mode, enabling bidirectional DC / DC conversion. The traction charger system achieves bidirectional DC / DC chopping through a shared power supply mode between the three-phase rectified DC bus and the power battery, as well as the charging and discharging functions of the power battery. During battery charging, it operates in DC / DC buck chopping mode, with energy flowing from left to right; during battery discharging, it operates in DC / DC boost chopping mode, with energy flowing from right to left. In charging mode, the intermediate DC bus voltage (DC 1200V-1800V) is converted to DC 1020V-1500V to charge the power battery. In discharging mode, the traction charger converts the power battery voltage (DC 1020V-1500V) to DC 1020V-1500V. The 1500V~1800V supply is used for the traction auxiliary system; the composite busbar 8 has 10 interfaces, namely S1, S2...S10; S1~S5 are located to the left of the water-cooled base plate 3, and S6~S10 are located to the right of the water-cooled base plate. S1, S2, S3, S6, S7, and S8 are the high-voltage electrical DC input interfaces of the power module. S1 and S6 are connected to the DC+ of the DC 1200V~1800V DC bus, S3 and S8 are connected to the DC- of the DC 1200V~1800V DC bus, and S3 and S7 are connected to... Point M; S4, S5, S9, and S10 are high-voltage electrical DC output interfaces, all connected to the outside via composite busbar 8. S4 connects to P1, S5 to N1, S9 to P2, and S10 to N2. The power module connects the required +15V power supply to the charger control unit via two 6-pin low-voltage connectors. The wiring harness uses 2*0.5mm² twisted-pair shielded cables, and the control unit input shielded cable is connected to the power module frame. The two 6-pin low-voltage connectors for the power signal are designated as X1 and X2. The wiring method for each power unit is as follows.

[0049] 1) In the first DC-DC power conversion module, such as Figure 9As shown, the first set of charger power units includes two full-bridge IGBTs. The upper and lower bridge arms of the two full-bridge IGBTs are defined as T1H, T1B, T2H, and T2B, respectively. The circuit principle is as follows: T1H and T1B are controlled to be turned on and off by the DBT1 driver board. A T1 configuration board for protection is provided between T1H and T1B and the DBT1 driver board. The DBT1 driver board is powered by a connector. The two ends of T1H and T1B connected in series are connected in parallel with a filter capacitor C1, and also in parallel with a slow-amplifier resistor CDR1. The two ends of CDR1 are connected to a composite... Between S1 and S2 of busbar 8, S2 is connected to point M; T2H and T2B are controlled to be turned on and off by the DBT2 driver board. A T2 configuration board for protection is provided between T2H and T2B and the DBT2 driver board. The DBT2 driver board is powered by a connector; the two ends of T2H and T2B connected in series are connected in parallel with a filter capacitor C2, and also in parallel with a slow-release resistor CDR2; the two ends of CDR2 are connected between S2 and S3 of the composite busbar 8; the slow-release resistor CDR3 is connected in parallel between S11 and S12 on the power battery side through terminal block 11.

[0050] The second set of charger power units includes two full-bridge IGBTs, such as Figure 9 As shown, the upper and lower arms of the two full-bridge IGBTs are defined as T3H, T3B, T4H, and T4B, respectively. The circuit principle is as follows: T3H and T3B are controlled to be turned on and off by the DBT3 driver board. A T3 configuration board for protection is provided between T3H and T3B and the DBT3 driver board. The DBT3 driver board is powered by a connector. A filter capacitor C3 is connected in parallel across the two ends of T3H and T3B after they are connected in series. It is also connected in parallel with a slow-amplification resistor CDR4. The two ends of CDR4 are connected to S6 and S7 of the composite busbar 8. Between points S7 and M; T4H and T4B are controlled to be turned on and off by the DBT4 driver board. A T4 configuration board for protection is provided between T4H and T4B and the DBT4 driver board. The DBT4 driver board is powered by a connector; the two ends of T4H and T4B connected in series are connected in parallel with a filter capacitor C4, and also in parallel with a slow-release resistor CDR5; the two ends of CDR5 are connected between S7 and S8 of the composite busbar 8; the slow-release resistor CDR6 is connected in parallel between S13 and S14 on the power battery side through a terminal block 11.

[0051] 2) In the second DC-DC power conversion module, such as Figure 9As shown, the first set of charger power units includes two full-bridge IGBTs. The upper and lower bridge arms of the two full-bridge IGBTs are defined as T1H, T1B, T2H, and T2B, respectively. The circuit principle is as follows: T1H and T1B are controlled to be turned on and off by the DBT1 driver board. A T1 configuration board for protection is provided between T1H and T1B and the DBT1 driver board. The DBT1 driver board is powered by a connector. The two ends of T1H and T1B connected in series are connected in parallel with a filter capacitor C1, and also in parallel with a slow-amplification resistor CDR7. The two ends of CDR7 are connected to a composite... Between S1 and S2 of busbar 8, S2 is connected to point M; T2H and T2B are controlled to be turned on and off by the DBT2 driver board. A T2 configuration board for protection is provided between T2H and T2B and the DBT2 driver board. The DBT2 driver board is powered by a connector; the two ends of T2H and T2B connected in series are connected in parallel with a filter capacitor C2, and also in parallel with a slow-release resistor CDR8; the two ends of CDR8 are connected between S2 and S3 of the composite busbar 8; the slow-release resistor CDR9 is connected in parallel between S11 and S12 on the power battery side through terminal block 11.

[0052] The second set of charger power units includes two full-bridge IGBTs, such as Figure 9 As shown, the upper and lower arms of the two full-bridge IGBTs are defined as T3H, T3B, T4H, and T4B, respectively. The circuit principle is as follows: T3H and T3B are controlled to be turned on and off by the DBT3 driver board. A T3 configuration board for protection is provided between T3H and T3B and the DBT3 driver board. The DBT3 driver board is powered by a connector. A filter capacitor C3 is connected in parallel between the two ends of T3H and T3B after they are connected in series, and it is also connected in parallel with the slow-release resistor CDR10. The two ends of CDR10 are connected between S6 and S7 of the composite busbar 8. S7 is connected to point M; T4H and T4B are controlled to be turned on and off by the DBT4 driver board. A T4 configuration board with a protective function is provided between T4H and T4B and the DBT4 driver board. The DBT4 driver board is powered by a connector; the two ends of T4H and T4B connected in series are connected in parallel with a filter capacitor C4, and also in parallel with a slow-release resistor CDR11; the two ends of CDR11 are connected between S7 and S8 of the composite busbar 8; the slow-release resistor CDR12 is connected in parallel between S13 and S14 on the power battery side through the terminal block 11.

[0053] The aforementioned charger power unit draws power from the intermediate DC bus (DC1200V-DC1800V). Switches T1H and T2B are alternately turned on at 180° intervals, with equal duty cycles, both greater than 50%. At any given time, at least one switch of T1H or T2B is turned on, and both can be turned on simultaneously. When T1H and T2B are both turned on, the front-end voltage of the output filter reactors CL1, CL2, CL3, and CL4 is 1800V. When either T1H or T2B is turned on, the output filter reactor C... The front-end voltages of L1, CL2, CL3, and CL4 are 900V, therefore the voltage at the reactor front end is an alternating pulse wave of 900V and 1800V. After output LC filtering, the output voltage is filtered to the required DC 1020V-DC 1500V. The output voltage and current are adjusted by changing the duty cycle of T1H and T2B. During operation, the anti-parallel diode of T2H works in conjunction with the IGBT of T1H, and the anti-parallel diode of T1B works in conjunction with the IGBT of T2B, alternately charging the power battery side. In charging mode, there are three operating modes: Figure 8 Let's take the bottom group as an example:

[0054] Charging Mode 1: The charger power unit draws power from the DC bus. The anti-parallel diode of T4H, in conjunction with the IGBT of T3H, conducts. After passing through the output-side LC filter, the power battery is charged. Figure 10 As shown.

[0055] Charging Mode 2: The charger power unit draws power from the DC bus. The anti-parallel diode of T3B, in conjunction with the IGBT of T4B, conducts. After passing through the output-side LC filter, the power battery is charged. Figure 11 As shown.

[0056] Charging Mode 3: The charger's power unit draws power from the DC bus. The IGBTs of T3H and T4B work together to conduct, and after passing through the output-side LC filter, the power battery is charged. Figure 12 As shown.

[0057] The above-mentioned discharge method for a DC-DC converter power module of a hybrid internal combustion engine vehicle involves the following steps: In discharge mode, the charger power module draws power from the power battery and charges the filter capacitors CFC3, CFC6, CFC9, and CFC12 of the four units respectively through a pre-charging circuit. The filter capacitors act as energy storage inductors and are boosted through a three-level circuit. T2 and T3 are alternately turned on at 180° intervals with equal duty cycles, both less than 50%. Then, the voltage is stabilized at DC1200V-DC1800V through a supporting capacitor. The output voltage and current are adjusted by changing the duty cycles of T2 and T3. During operation, the anti-parallel diode of T4 works in conjunction with the conduction of T2, and the anti-parallel diode of T1 works in conjunction with the conduction of the IGBT of T3, alternately discharging to the DC bus side. Specifically, there are two operating modes as follows: Figure 8 Let's take the bottom group as an example.

[0058] Discharge Mode 1: The charger power unit draws power from the power battery and charges the filter capacitor CFC12 of the four units respectively through the pre-charge circuit, while the remaining units are charged by CFC3, CFC6, and CFC9; the anti-parallel diode of T4B, in conjunction with the IGBT of T3B, conducts, discharging to the DC bus side, such as... Figure 13 As shown.

[0059] Discharge Mode 2: The charger power unit draws power from the power battery and charges the filter capacitor CFC12 of the four units through the pre-charge circuit, while the remaining units are charged by CFC3, CFC6, and CFC9; the anti-parallel diode of T3H, in conjunction with the IGBT of T4H, conducts, discharging to the DC bus side, such as... Figure 14 As shown.

[0060] The aforementioned DC-DC power conversion module is applied to the hybrid internal combustion engine vehicle in this embodiment, and its performance parameters are as follows: discharge power: 315kW; maximum discharge power: 400kW; discharge voltage: 1020V~1500V DC; output voltage: 1600V~1800V DC; discharge current: 310A; maximum discharge current: 390A; switching frequency: 3kHz.

[0061] A hybrid power supply control method for a hybrid internal combustion locomotive, combining a diesel engine and a power battery, utilizes the aforementioned DC-DC converter power module for the hybrid internal combustion locomotive. The control block diagram is shown below. Figure 15As shown, the vehicle is primarily powered by the power battery. When the battery level is low and the traction handle is in a low position, the vehicle operates solely on the power battery, performing traction, braking, and coasting. When the battery level is low, the diesel engine starts and charges the power battery. Once the battery is fully charged, the diesel engine stops operating, and the power battery operates independently. In mixed conditions, when the traction handle is in a low position, the diesel engine provides traction and charges the power battery. When the traction handle is in a high position or the power battery's power is insufficient, the diesel engine and power battery provide combined traction. When the vehicle is stopped, the diesel engine charges the power battery. The specific traction mode switching process is as follows: Figure 16 As shown:

[0062] 1) After the vehicle is powered on, turn on the battery discharge enable and enter the pure power battery coasting mode; when the power battery charge is low, start the diesel engine, turn on the excitation enable, the diesel engine speed increases, the excitation connects the power and bus voltage, the traction charger turns off the discharge enable and turns on the charging enable, and the diesel engine charges the power battery.

[0063] 2) When a traction signal is received during the pure power battery coasting operation, the pure power battery traction operation is entered; when the handle is in a high position or the power battery power is insufficient, the diesel engine is started, the excitation is enabled, the diesel engine speed is increased, and the excitation controller and the traction charger jointly control the power and bus voltage, thus entering the mixed traction operation of diesel engine and power battery.

[0064] 3) When a traction signal is received during the pure power battery coasting operation, the system enters the pure power battery traction operation; when the power battery charge is low, the diesel engine is started, the excitation is enabled, the diesel engine speed is increased, the excitation control power and bus voltage are adjusted, the traction charger is turned off the discharge enable and turned on the charging enable, and the system enters the diesel engine traction and power battery charging operation.

[0065] 4) Under the mixed traction conditions of diesel engine and power battery, when the handle is turned to the low position, the traction charger turns off the discharge enable and turns on the charging enable, and enters the diesel engine traction and power battery charging condition; when the handle is turned to the high position, the traction charger turns off the charging enable and turns on the discharge enable, and enters the mixed traction condition of diesel engine and power battery.

[0066] 5) When the diesel engine is traction and charging the power battery, and the battery is fully charged, the traction charger turns off the charging enable and turns on the discharging enable. The traction charger takes over the power and bus voltage control, and the diesel engine stops. If there is no traction signal, it enters the pure power battery coasting mode. If there is a traction signal, it enters the pure power battery traction mode.

[0067] The control principles of the above-mentioned hybrid power supply control method for diesel engine and power battery are as follows:

[0068] 1) Overall control principle: The vehicle is mainly powered by the power battery. When the battery power is low or the traction handle is in a low position, the vehicle operates solely by the power battery. When the battery power is low or the power battery output power is insufficient, the diesel engine starts and starts working.

[0069] 2) Diesel engine and power battery traction mode switching and control principles of each part: In pure power battery mode, the traction charger controls the bus voltage and output power; in hybrid mode, the excitation controller controls the main generator output power and bus voltage value. The traction charger only maintains the lower limit of the bus voltage value and the upper limit of the bus voltage value when discharging stops, automatically adjusts the power according to demand, and ensures that the discharge power of the four power batteries is consistent; during the switching process between pure power battery and hybrid mode, the original output torque remains unchanged, and the new mode is executed after the switching is completed.

[0070] 3) Traction, braking, and coasting control principles: When a traction signal is received, if the handle position is low and the battery power is sufficient, the pure power battery will discharge for traction; if the handle position is low but the battery power is low, the diesel engine will start for traction and charge the power battery; when the handle position is high, the diesel engine and the power battery will discharge together for traction.

[0071] ① During coasting operation, when the battery power is low, the diesel engine starts and charges the power battery. When the battery is fully charged, the diesel engine stops working.

[0072] ② Under braking conditions, the CCU continuously sends charging commands to the traction charger, and the power battery absorbs the feedback energy from the electric braking.

[0073] ③ When switching between traction and braking, the CCU must first send the required charging or discharging mode (such as charging or discharging) to the traction charger. After the traction charger completes the switching and uploads the status, the CCU will then issue a new traction or braking command.

[0074] 4) Traction charger charging mode: Under all charging conditions, the CCU sends the upper limit of the charging voltage to the traction charger control unit; when the upper limit of the voltage is not reached, the traction charger performs constant power charging; when the power battery voltage reaches the upper limit, the traction charger performs constant voltage charging.

[0075] Table 1 Operating Condition Description

[0076]

[0077]

[0078]

[0079] The scope of protection claimed by this invention is not limited to the specific embodiments described above. Moreover, for those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A DC-DC converter power module for a hybrid internal combustion locomotive, characterized in that: It includes a frame assembly, a water-cooling assembly, two sets of composite busbars (8) and power devices; the water-cooling assembly includes a water-cooling substrate (3) with a water-cooling channel inside; the power devices include an IGBT module (1) and a slow-release resistor (4); the frame assembly includes a left frame assembly (9) and a right frame assembly (10). Two sets of IGBT modules (1) are installed on the front of the left side wall of the water-cooled substrate (3). Each set of IGBT modules (1) is provided with a corresponding configuration board (2). Four sets of slow-release resistors (4) are installed on the rear of the left side wall of the water-cooled substrate (3). The IGBT modules (1) on the left side and the four sets of slow-release resistors (4) are all connected by bolts to the corresponding screw holes. Moreover, an L-shaped isolation insulating plate (14) is installed between the slow-release resistors (4) and the IGBT modules (1). The L-shaped isolation insulating plate (14) is provided with fixing holes and cable tie holes. The type of isolation insulation board (14) is also installed on the corresponding screw holes by bolt connection. The front end of the water-cooled substrate (3) is connected to two sets of insulation support seats (5). One set of composite busbars (8) is located on the left side of the left IGBT module (1) and is connected to the insulation support seat (5) and the left IGBT module (1). The left composite busbar (8) is connected to the high voltage through the copper nut inside the insulation support seat (5). The outer wall of the left composite busbar (8) is also provided with an absorption capacitor (7) and a connection terminal for connecting the slow release resistor (4). Two sets of IGBT modules (1) are installed on the front of the right side wall of the water-cooled substrate (3). Each set of IGBT modules (1) is provided with a corresponding configuration board (2). Two sets of slow-release resistors (4) are installed on the rear of the right side wall of the water-cooled substrate (3). The IGBT modules (1) on the right side and the two sets of slow-release resistors (4) are all installed on the corresponding screw holes by bolt connection. Moreover, an L-shaped isolation insulation plate (14) is installed between the slow-release resistor (4) and the IGBT module (1). The L-shaped isolation insulation plate (14) is provided with fixing holes and cable tie holes. The L-shaped isolation insulation plate (14) is also installed on the corresponding screw holes by bolt connection. Another set of composite busbars (8) The composite busbar (8) is located on the right side of the IGBT module (1) and is connected to the insulating support base (5) and the IGBT module (1) on the right side. The composite busbar (8) on the right side is also connected to the high voltage through the copper nut inside the insulating support base (5). The outer wall of the composite busbar (8) on the right side is also provided with an absorption capacitor (7) and a connection terminal for connecting the slow-release resistor (4). The installation positions of the IGBT module (1), slow-release resistor (4) and L-shaped isolation insulation plate (14) on the left side are parallel and misaligned with the installation positions of the IGBT module (1), slow-release resistor (4) and L-shaped isolation insulation plate (14) on the right side. Therefore, the screw holes for installation are also misaligned accordingly. The left frame component (9) is located outside the left composite busbar (8). The left frame component (9) includes an integrally formed upper heat dissipation plate I (901), an intermediate mounting plate I (902), and a lower heat dissipation plate I (903). The upper heat dissipation plate I (901), the intermediate mounting plate I (902), and the lower heat dissipation plate I (903) are in an "L" shape. The upper heat dissipation plate I (901) and the lower heat dissipation plate I (90) each have a plurality of heat dissipation and observation windows (15). The edges of the upper heat dissipation plate I (901) and the lower heat dissipation plate I (903) are bent inward, and a plurality of connection ends connected to the water-cooled substrate (3) are provided on both the front and rear sides. The connection ends are connected to the corresponding frame mounting holes (303) of the water-cooled substrate (3). Two sets of drive board components (6) used in matching with the IGBT module (1) on the left side are also provided and are installed on the outer wall of the intermediate mounting plate I (902). A row of four terminal blocks (11) is further installed at the lower part in front of the intermediate mounting plate I (902). A cover plate (12) is further provided outside the left drive board component (6). The cover plate (12) is in an "L" shape. The edges of the upper and lower parts of the cover plate (12) are bent outward, and the bent parts are connected to the intermediate mounting plate I (902) by bolts. A window is further opened in each of the upper and lower parts of the cover plate (12). A dust-proof baffle is fixedly provided at the rear side of the cover plate (12). The right frame component (10) is located outside the right composite busbar (8). The right frame component (10) includes an integrally formed upper heat dissipation plate II (1001), an intermediate mounting plate II (1002), and a lower heat dissipation plate II (1003). The upper heat dissipation plate II (1001), the intermediate mounting plate II (1002), and the lower heat dissipation plate II (1003) are in an "L" shape. The upper heat dissipation plate II (1001) and the lower heat dissipation plate II (1003) each have a plurality of heat dissipation and observation windows (15). The edges of the upper heat dissipation plate II (1001) and the lower heat dissipation plate II (1003) are bent inward, and a plurality of connection ends connected to the water-cooled substrate (3) are provided on both the front and rear sides. The connection ends are connected to the corresponding frame mounting holes (303) of the water-cooled substrate (3). Two sets of drive board components (6) used in matching with the IGBT module (1) on the right side are also provided and are installed on the outer wall of the intermediate mounting plate II (1002). A cover plate (12) is further provided outside the right drive board component (6). The structure of the cover plate (12) is opposite and symmetrical to the structure of the left cover plate (12). The frame mounting holes (303) of the water-cooled substrate (3) where the left frame component (9) is installed and the frame mounting holes (303) of the water-cooled substrate (3) where the right frame component (10) is installed are mutually misaligned, so that their respective connection ends are also misaligned. The rear end of the water-cooled substrate (3) is connected to two guide posts (13). The rear side of the water-cooled substrate (3) is also provided with a water inlet (301) and a water outlet (302). The water inlet (301) is located at the bottom and the water outlet (302) is located at the top. The interior of the water-cooled substrate (3) is set with flow channels according to the positions of the IGBT module (1) and the slow-release resistor (4). The flow channels are M-shaped. The composite busbars (8) on the left and right sides are each provided with 5 external high-voltage electrical interfaces.

2. The DC-DC converter power module for a hybrid internal combustion locomotive according to claim 1, characterized in that: The power devices on the left side of the water-cooled substrate (3) are arranged as follows: IGBT modules (1) are arranged one at the top and one at the bottom, namely T1 and T2 respectively; the slow discharge resistors (4) are divided into two rows, with the upper left row having a slow discharge resistor CDR3 or CDR9 on the power battery side, the upper right row having a slow discharge resistor CDR1 or CDR7 on the middle DC bus side, the lower left row having a slow discharge resistor CDR6 or CDR12 on the power battery side, the lower right row having a slow discharge resistor CDR2 or CDR8 on the middle DC bus side, and two absorption capacitors C1 and C2; the power devices on the right side of the water-cooled substrate (3) are arranged as follows: IGBT modules (1) are arranged one at the top and one at the bottom, namely T4 and T3 respectively, slow discharge The resistor (4) is divided into two rows. The upper row is a slow-release resistor CDR5 or CDR11 on the middle DC bus side, and the lower row is a slow-release resistor CDR4 or CDR10 on the middle DC bus side. There are two absorption capacitors C3 and C4. The full-bridge IGBT formed by T1 and T2 and the full-bridge IGBT formed by T4 and T3 are connected to the composite bus for high voltage electrical connection. One end of the two slow-release resistors on the middle DC bus side is connected to the auxiliary terminals of DC+ and DC- of the composite bus, and the other end is connected to the auxiliary terminal of the middle M end of the composite bus after being shorted by the copper bus. The two slow-release resistors on the power battery side are fixed to the power module terminal block through 4 high-voltage wire harnesses and connected to the corresponding wire harness in the converter cabinet.

3. The DC-DC converter power module for a hybrid internal combustion locomotive according to claim 1, characterized in that: The cover plate (12) is semi-transparent.

4. The DC-DC converter power module for a hybrid internal combustion locomotive according to claim 1, characterized in that: The heat dissipation and observation window (15) is circular.

5. A DC-DC converter power module for a hybrid internal combustion locomotive according to claim 2, characterized in that: The DC-DC power conversion module is applied to the traction charger system, including four traction chargers. The four traction charger power units are integrated in pairs on a DC-DC power conversion module. Each DC-DC power conversion module contains two charger power units. The DC-DC power conversion module adopts a three-level working mode to realize bidirectional DC / DC conversion function. The traction charger system realizes bidirectional DC / DC chopping function through the common power supply mode of the DC bus after three-phase rectification and the power battery and the charging and discharging function of the power battery. When the battery is charging, it is in DC / DC buck chopping mode, and the energy flows from left to right. When the battery is discharging, it is in DC / DC boost chopping mode, and the energy flows from right to left. The composite busbar (8) has 10 interfaces, namely S1, S2...S10. The ones located on the left side of the water-cooled substrate (3) are S1~S5. Located on the right side of the water-cooled substrate (3) are S6~S10. S1, S2, S3, S6, S7, and S8 are the high-voltage electrical DC input interfaces of the power module. S1 and S6 are connected to the DC+ of the DC1200V~1800V DC bus, S3 and S8 are connected to the DC- of the DC1200V~1800V DC bus, and S3 and S7 are connected to point M. S4, S5, S9, and S10 are the high-voltage electrical DC output interfaces, all of which are connected to the outside through the composite busbar (8). S4 is connected to P1, S5 is connected to N1, S9 is connected to P2, and S10 is connected to N2. The power module connects the required +15V power supply to the charger control unit through two 6-core low-voltage connectors. The wiring harness uses 2*0.5mm2 twisted pair shielded wires, and the control unit input shielded wire is connected to the power module frame. The two 6-core low-voltage connectors for the power signal are designated as X1 and X2. 1) Within the first DC-DC power conversion module, the first set of charger power units includes two full-bridge IGBTs. The upper and lower bridge arms of the two full-bridge IGBTs are defined as T1H, T1B, T2H, and T2B, respectively. The circuit principle is as follows: T1H and T1B are controlled to be turned on and off by the DBT1 driver board. A T1 configuration board for protection is provided between T1H and T1B and the DBT1 driver board. The DBT1 driver board is powered by a connector. A filter capacitor C1 is connected in parallel between the two ends of T1H and T1B after they are connected in series, and it is also connected in parallel with a slow-amplifier resistor CDR1. The two ends of CDR1 are connected to... Between S1 and S2 of the composite busbar (8), S2 is connected to point M; T2H and T2B are controlled to be turned on and off by the DBT2 drive board. A T2 configuration board with a protective function is provided between T2H and T2B and the DBT2 drive board. The DBT2 drive board is powered by a connector; the two ends of T2H and T2B connected in series are connected in parallel with a filter capacitor C2, and also in parallel with a slow-release resistor CDR2; the two ends of CDR2 are connected between S2 and S3 of the composite busbar (8); the slow-release resistor CDR3 is connected in parallel between S11 and S12 on the power battery side through a terminal block (11); The second set of charger power units includes two full-bridge IGBTs. The upper and lower bridge arms of the two full-bridge IGBTs are defined as T3H, T3B, T4H, and T4B, respectively. The circuit principle is as follows: T3H and T3B are controlled to be turned on and off by the DBT3 driver board. A protective T3 configuration board is provided between T3H and T3B and the DBT3 drive board. The DBT3 drive board is powered by a connector. The two ends of T3H and T3B connected in series are connected in parallel with a filter capacitor C3, and also in parallel with a slow-release resistor CDR4. The two ends of CDR4 are connected between S6 and S7 of the composite busbar (8), and S7 is connected to point M. T4H and T4B are controlled to be turned on and off by the DBT4 drive board. A protective T4 configuration board is provided between T4H and T4B and the DBT4 drive board. The DBT4 drive board is powered by a connector. The two ends of T4H and T4B connected in series are connected in parallel with a filter capacitor C4, and also in parallel with a slow-release resistor CDR5. The two ends of CDR5 are connected between S7 and S8 of the composite busbar (8). The slow-release resistor CDR6 is connected in parallel between S13 and S14 on the power battery side through a terminal block (11). 2) Within the second DC-DC power module, the first set of charger power units includes two full-bridge IGBTs. The upper and lower arms of the two full-bridge IGBTs are defined as T1H, T1B, T2H, and T2B, respectively. The circuit principle is as follows: T1H and T1B are controlled to be turned on and off by the DBT1 driver board. A T1 configuration board for protection is provided between T1H and T1B and the DBT1 driver board. The DBT1 driver board is powered by a connector. A filter capacitor C1 is connected in parallel between the two ends of T1H and T1B after they are connected in series, and it is also connected in parallel with a slow-amplifier resistor CDR7. The two ends of CDR7 are connected to... Between S1 and S2 of the composite busbar (8), S2 is connected to point M; T2H and T2B are controlled to be turned on and off by the DBT2 drive board. A T2 configuration board with a protective function is provided between T2H and T2B and the DBT2 drive board. The DBT2 drive board is powered by a connector; the two ends of T2H and T2B connected in series are connected in parallel with a filter capacitor C2, and also in parallel with a slow-release resistor CDR8; the two ends of CDR8 are connected between S2 and S3 of the composite busbar (8); the slow-release resistor CDR9 is connected in parallel between S11 and S12 on the power battery side through a terminal block (11); The second set of charger power units includes two full-bridge IGBTs. The upper and lower bridge arms of the two full-bridge IGBTs are defined as T3H, T3B, T4H, and T4B, respectively. The circuit principle is as follows: T3H and T3B are controlled to be turned on and off by the DBT3 driver board. A T3 configuration board with a protection function is provided between T3H and T3B and the DBT3 driver board. The DBT3 driver board is powered by a connector. The two ends of T3H and T3B connected in series are connected in parallel with a filter capacitor C3, and also in parallel with a slow-release resistor CDR10. The two ends of CDR10 are connected to the composite busbar (8). Between S6 and S7, S7 is connected to point M; T4H and T4B are controlled to be turned on and off by the DBT4 driver board. A T4 configuration board with a protective function is provided between T4H and T4B and the DBT4 driver board. The DBT4 driver board is powered by a connector; the two ends of T4H and T4B connected in series are connected in parallel with a filter capacitor C4, and also connected in parallel with a slow-release resistor CDR11; the two ends of CDR11 are connected between S7 and S8 of the composite busbar (8); the slow-release resistor CDR12 is connected in parallel between S13 and S14 on the power battery side through a terminal block (11).

6. The charging method for a DC-DC converter power module of a hybrid internal combustion locomotive as described in claim 5, characterized in that: The charger power unit draws power from the intermediate DC bus (DC1200V-DC1800V). Switches T1H and T2B are alternately turned on at 180° intervals, with equal duty cycles, both greater than 50%. At any given time, at least one switch of T1H or T2B is on, and both can be on simultaneously. When T1H and T2B are on simultaneously, the voltage at the front end of the output filter reactors CL1, CL2, CL3, and CL4 is 1800V. When only one of T1H or T2B is on, the voltage at the front end of the output filter reactor CL1...

1. The front-end voltage of CL2, CL3, and CL4 is 900V, so the voltage at the front end of the reactor is an alternating pulse wave of 900V and 1800V. After output LC filtering, the output voltage is filtered to the required DC1020V-DC1500V. The output voltage and current are adjusted by adjusting the duty cycle of T1H and T2B. During operation, the anti-parallel diode of T2H works with the IGBT of T1H to conduct, and the anti-parallel diode of T1B works with the IGBT of T2B to conduct, alternately charging the power battery side.

7. The discharge method for a DC-DC converter power module of a hybrid internal combustion locomotive as described in claim 5, characterized in that: In discharge mode, the charger power module draws power from the power battery and charges the filter capacitors CFC3, CFC6, CFC9, and CFC12 of the four units through the pre-charge circuit. The filter capacitors act as energy storage inductors and are boosted through a three-level circuit. T2 and T3 are turned on alternately by 180° with equal duty cycles, and the duty cycles are all less than 50%. Then, the voltage is stabilized at DC1200V-DC1800V through the support capacitor. The output voltage and current are adjusted by adjusting the duty cycles of T2 and T3. During operation, the anti-parallel diode of T4 works with T2 to conduct, and the anti-parallel diode of T1 works with the IGBT of T3 to conduct, which alternately discharge to the DC bus side.

8. A hybrid power supply control method for a diesel engine and a power battery in a hybrid internal combustion locomotive, using the DC-DC converter power module for a hybrid internal combustion locomotive as described in claim 5, characterized in that: The vehicle is powered primarily by the power battery. Unless the battery charge is low or the traction handle is in a low position, the entire vehicle operates solely on the power battery, performing traction, braking, and coasting operations. When the battery is low, the diesel engine starts and charges the power battery; when the battery is fully charged, the diesel engine stops working, and the power battery operates independently; in mixed conditions, when the traction lever is at a low position, the diesel engine provides traction and charges the power battery; when the traction lever is at a high position or the power battery's power is insufficient, the diesel engine and power battery provide traction in combination; when the vehicle is stopped, the diesel engine charges the power battery; the traction mode switching process is as follows: 1) After the vehicle is powered on, turn on the battery discharge enable and enter the pure power battery coasting mode; when the power battery charge is low, start the diesel engine, turn on the excitation enable, the diesel engine speed increases, the excitation control power and bus voltage are adjusted, the traction charger turns off the discharge enable and turns on the charging enable, and the diesel engine charges the power battery. 2) When a traction signal is received during the pure power battery coasting operation, the pure power battery traction operation is entered; when the handle is in a high position or the power battery power is insufficient, the diesel engine is started, the excitation is enabled, the diesel engine speed is increased, and the excitation controller and the traction charger jointly control the power and bus voltage, thus entering the mixed traction operation of diesel engine and power battery. 3) When a traction signal is received during the pure power battery coasting operation, the system enters the pure power battery traction operation; when the power battery charge is low, the diesel engine is started, the excitation is enabled, the diesel engine speed is increased, the excitation control power and bus voltage are adjusted, the traction charger is turned off the discharge enable and turned on the charging enable, and the system enters the diesel engine traction and power battery charging operation. 4) Under the mixed traction conditions of diesel engine and power battery, when the handle is turned to the low position, the traction charger turns off the discharge enable and turns on the charging enable, and enters the diesel engine traction and power battery charging condition; when the handle is turned to the high position, the traction charger turns off the charging enable and turns on the discharge enable, and enters the mixed traction condition of diesel engine and power battery. 5) When the diesel engine is traction and charging the power battery, and the battery is fully charged, the traction charger turns off the charging enable and turns on the discharging enable. The traction charger takes over the power and bus voltage control, and the diesel engine stops. If there is no traction signal, it enters the pure power battery coasting mode. If there is a traction signal, it enters the pure power battery traction mode.

9. The hybrid power supply control method for a hybrid internal combustion locomotive diesel engine and a power battery according to claim 8, characterized in that: The control principles are as follows: 1) Overall control principle: The vehicle is mainly powered by the power battery. When the battery power is low or the traction handle is in a low position, the vehicle operates solely by the power battery. When the battery power is low or the power battery output power is insufficient, the diesel engine starts and starts working. 2) Diesel engine and power battery traction mode switching and control principles of each part: In pure power battery mode, the traction charger controls the bus voltage and output power; in hybrid mode, the excitation controller controls the main generator output power and bus voltage value. The traction charger only maintains the lower limit of the bus voltage value and the upper limit of the bus voltage value when discharging stops, automatically adjusts the power according to demand, and ensures that the discharge power of the four power batteries is consistent; during the switching process between pure power battery and hybrid mode, the original output torque remains unchanged, and the new mode is executed after the switching is completed. 3) Traction, braking, and coasting control principles: When a traction signal is received, if the handle position is low and the battery power is sufficient, the pure power battery will discharge for traction; if the handle position is low but the battery power is low, the diesel engine will start for traction and charge the power battery; when the handle position is high, the diesel engine and the power battery will discharge together for traction. ① During coasting operation, when the battery power is low, the diesel engine starts and charges the power battery. When the battery is fully charged, the diesel engine stops working. ② Under braking conditions, the CCU continuously sends charging commands to the traction charger, and the power battery absorbs the feedback energy from the electric braking. ③ When switching between traction and braking, the CCU must first send the required charging and discharging mode to the traction charger. After the traction charger completes the switching and uploads the status, the CCU will then issue a new traction or braking command. 4) Traction charger charging mode: Under all charging conditions, the CCU sends the upper limit of the charging voltage to the traction charger control unit; When the voltage limit is not reached, the traction charger performs constant power charging; when the power battery voltage reaches the upper limit, the traction charger performs constant voltage charging.

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