Locomotive electrical system and locomotive power supply control method

Abstract

The invention discloses a locomotive electrical system and a locomotive power supply control method, and the locomotive electrical system is characterized in that the high-voltage input end of a traction transformer is electrically connected with a locomotive contact net through the rising of a pantograph, or is electrically disconnected with the locomotive contact net through the falling of the pantograph; the input end of the four-quadrant rectifier module is connected with the low-voltage output end of the traction transformer; the auxiliary load module, the power battery module and the traction module are respectively connected with the output end of the at least one four-quadrant rectification module; the power battery module is used for storing energy and supplying power to the locomotive; the traction module is used for traction locomotive driving and / or kinetic energy recovery. The invention provides a locomotive electrical system. An auxiliary load module, a power battery module and a traction module are connected to the output end of a four-quadrant rectification module. The auxiliary load module, the power battery module and the traction module operate independently so that a charging strategy can be controlled conveniently, and charging of a power battery of a locomotive electrical system can be achieved when a locomotive operates.

Description

Technical Field

[0001] This invention relates to the field of railway locomotive operation control technology, and in particular to a locomotive electrical system and a locomotive power supply control method. Background Technology

[0002] With the depletion of coal and oil resources and the development of high-power battery technology, dual-power electric locomotives using both pantograph-catenary and battery power are suitable for most locomotive operating environments. On electrified railways, pantograph-catenary power can be used, while on non-electrified railways, battery power can replace diesel locomotives to meet normal traction functions, achieving the goal of energy conservation, emission reduction, and multi-purpose use of a single locomotive.

[0003] Since the power battery is an energy storage device, it needs to be recharged when its power is depleted to continue operation. Charging is mainly achieved by obtaining power from the overhead contact line through a pantograph. In existing technologies, locomotives need to stop for static charging, which takes extra time and results in low charging efficiency. Summary of the Invention

[0004] This invention provides a locomotive electrical system and a locomotive power supply control method to solve the problem of low locomotive charging efficiency in the current technology.

[0005] According to one aspect of the present invention, a locomotive electrical system is provided, the locomotive electrical system comprising: a pantograph, a traction transformer, at least one four-quadrant rectifier module, at least one auxiliary load module, at least one power battery module, and at least one traction module;

[0006] The high-voltage input terminal of the traction transformer is electrically connected to the locomotive contact network through the raising of the pantograph, or electrically disconnected from the locomotive contact network through the lowering of the pantograph.

[0007] The input terminal of the four-quadrant rectifier module is connected to the low-voltage output terminal of the traction transformer; the four-quadrant rectifier module is used for four-quadrant rectification.

[0008] The auxiliary load module, the power battery module, and the traction module are each connected to the output terminal of at least one of the four-quadrant rectifier modules;

[0009] The auxiliary load module includes the auxiliary load of the locomotive; the power battery module is used for energy storage and power supply to the locomotive; the traction module is used for traction of the locomotive and / or kinetic energy recovery.

[0010] Optionally, the power battery module includes: at least one power battery and at least one bidirectional battery.

[0011] DC-DC module;

[0012] The power battery is connected to the bidirectional DC-DC module in a one-to-one correspondence; the bidirectional DC-DC module is also connected to the output terminal of at least one of the four-quadrant rectifier modules;

[0013] The power battery is used for energy storage and power supply to the locomotive, and the bidirectional DC-DC module is used for DC step-down.

[0014] Optionally, the traction module includes: a braking resistor module, a traction converter, and at least one traction motor;

[0015] The first end of the traction converter is connected to the output end of at least one of the four-quadrant rectifier modules, and the second end of the traction converter is connected to at least one of the traction motors.

[0016] The output terminal of the traction converter is connected to the braking resistor module;

[0017] The traction converter is used to step down the voltage between the first and second terminals and between the second terminal and the output terminal; the braking resistor module is used to convert electrical energy into heat energy.

[0018] Optionally, the auxiliary load module includes: at least one first auxiliary load module and at least one second auxiliary load module;

[0019] The input terminals of the first auxiliary load module and the second auxiliary load module are connected to the output terminal of at least one of the four-quadrant rectifier modules;

[0020] The first auxiliary load module is used to supply power to the variable voltage and variable frequency load; the second auxiliary load module is used to supply power to the constant voltage and constant frequency load.

[0021] Optionally, the auxiliary load module, the power battery module, and the traction module are connected to the output terminal of the four-quadrant rectifier module via the DC bus.

[0022] According to another aspect of the present invention, a locomotive power supply control method is provided, applied to the locomotive electrical system of any embodiment of the present invention, comprising:

[0023] When the locomotive's pantograph is in the raised position, the traction power of the traction motor in the traction module and the actual power of the auxiliary inverter in the auxiliary load module are obtained.

[0024] The maximum charging power of the power battery in the power battery module is determined based on the traction power and the actual power of the auxiliary inverter; the power battery is then charged based on the maximum charging power of the power battery.

[0025] Optionally, determining the maximum charging power of the power battery in the power battery module based on the traction power and the actual power of the auxiliary inverter includes:

[0026] Obtain the rated capacity of the traction transformer, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module.

[0027] The remaining capacity of the traction transformer is determined based on the rated capacity of the traction transformer, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module.

[0028] The maximum charging power of the power battery is determined based on the remaining capacity of the traction transformer and the actual power of the auxiliary inverter.

[0029] The relationship between the remaining capacity of the traction transformer and its rated capacity, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module includes:

[0030]

[0031] Among them, S n S represents the remaining capacity of the traction transformer, S represents the rated capacity of the traction transformer, and η represents the remaining capacity of the traction transformer. m η is the motor efficiency of the traction motor. t η is the mechanical transmission efficiency of the traction motor. i For the converter efficiency of the traction converter, P n The traction power of the traction motor;

[0032] The relationship between the maximum charging power of the power battery, the remaining capacity of the traction transformer, and the actual power of the auxiliary inverter includes:

[0033] P b =S n -P a -C;

[0034] Among them, P a To assist the actual power of the inverter, P b C represents the maximum charging power of the power battery, and C is a constant.

[0035] Optionally, charging the power battery according to its maximum charging power includes:

[0036] The maximum charging current of the power battery is obtained based on the maximum charging power of the power battery.

[0037] The relationship between the maximum charging current of the power battery and the allowable charging current of the power battery is determined, and proportional-integral control is performed on the power battery module in the locomotive electrical system to charge it with the minimum current value.

[0038] Optionally, the traction module includes: a braking resistor module, a traction converter, and at least one traction motor; the locomotive power supply control method includes:

[0039] When the locomotive's pantograph is in the lowered state, the electrical energy generated by the electric braking of the traction motor is used to charge the power battery module.

[0040] Optionally, the locomotive electrical system includes a DC bus, and the auxiliary load module, the power battery module, and the traction module are respectively connected to the output terminal of the four-quadrant rectifier module through the DC bus; the step of charging the power battery module with the electrical energy generated by the electric braking of the traction motor includes:

[0041] The real-time voltage of the DC bus is obtained, and when the real-time voltage of the DC bus is less than a first preset threshold, the power battery module supplies power to the locomotive electrical system.

[0042] When the real-time voltage of the DC bus is greater than or equal to the first preset threshold, the power battery module is charged using the electrical energy generated by the electric braking of the traction motor.

[0043] When the real-time voltage of the DC bus is greater than or equal to the second preset threshold, the braking resistor module consumes part of the electrical energy to reduce the real-time voltage of the DC bus.

[0044] The second preset threshold is greater than or equal to the first preset threshold.

[0045] This invention provides a locomotive electrical system and a locomotive power supply control method. The locomotive electrical system includes: an input terminal of a four-quadrant rectifier module connected to the low-voltage output terminal of a traction transformer; an auxiliary load module, a power battery module, and a traction module each connected to the output terminal of at least one four-quadrant rectifier module; a power battery module for energy storage and power supply to the locomotive; and a traction module for traction and / or kinetic energy recovery. In the locomotive electrical system of this embodiment, the electrical topology is simple, the auxiliary load module, power battery module, and traction module are connected in parallel, and the independent operation of the auxiliary load module, power battery module, and traction module facilitates control of the charging strategy. Charging of the power battery of the locomotive electrical system can also be achieved while the locomotive is running. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of the structure of a locomotive electrical system provided in an embodiment of the present invention;

[0048] Figure 2 This is a schematic diagram of another locomotive electrical system provided in an embodiment of the present invention;

[0049] Figure 3 This is a schematic diagram of another locomotive electrical system provided in an embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of another locomotive electrical system provided in an embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of another locomotive electrical system provided in an embodiment of the present invention;

[0052] Figure 6 A flowchart of a locomotive power supply control method provided in an embodiment of the present invention;

[0053] Figure 7 A flowchart of another locomotive power supply control method provided in an embodiment of the present invention;

[0054] Figure 8 A flowchart of another locomotive power supply control method provided in an embodiment of the present invention;

[0055] Figure 9 A flowchart of another locomotive power supply control method provided in an embodiment of the present invention;

[0056] Figure 10 A flowchart of another locomotive power supply control method provided in an embodiment of the present invention. Detailed Implementation

[0057] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0058] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0059] Figure 1 This is a schematic diagram of the structure of a locomotive electrical system provided in an embodiment of the present invention, such as... Figure 1 As shown, the locomotive electrical system includes: a pantograph 01, a traction transformer 02, at least one four-quadrant rectifier module 03, at least one auxiliary load module 04, at least one power battery module 05, and at least one traction module 06. The high-voltage input terminal of the traction transformer 02 is electrically connected to the locomotive's overhead contact line via the raising of the pantograph 01, or electrically disconnected from the overhead contact line via the lowering of the pantograph 01. The input terminal of the four-quadrant rectifier module 03 is connected to the low-voltage output terminal of the traction transformer 02. The four-quadrant rectifier module 03 is used for four-quadrant rectification. The auxiliary load module 04, the power battery module 05, and the traction module 06 are respectively connected to the output terminal of at least one four-quadrant rectifier module 03. The auxiliary load module 04 includes the locomotive's auxiliary load. The power battery module 05 is used for energy storage and power supply to the locomotive. The traction module 06 is used for traction of the locomotive and / or kinetic energy recovery.

[0060] Specifically, the high-voltage input terminal of the traction transformer 02 is electrically connected to the locomotive's overhead contact line via the raising of the pantograph 01, or electrically disconnected from the overhead contact line via the lowering of the pantograph 01. The locomotive's overhead contact line transmits 25kV, 50Hz high-voltage electricity. When the pantograph 01 is raised, high-voltage electricity is input to the input terminal of the traction transformer 02. After being transformed by the traction transformer 02, the high-voltage electricity is input to the four-quadrant rectifier module 03. The four-quadrant rectifier module 03 rectifies the low-voltage AC power and outputs DC power. Optionally, the four-quadrant rectifier module 03 outputs DC 1800V DC power.

[0061] The auxiliary load module 04 includes the locomotive's auxiliary loads, exemplarily including loads such as air conditioning and lighting. The power battery module 05 includes the locomotive's power source. The locomotive electrical system provided in this embodiment of the invention has two power supply methods: obtaining electrical energy from the contact network via a pantograph or using energy from the power battery module 05. When the traction module 06 is in a powered state, it is used to traction the locomotive. When the locomotive applies electric braking force using the brake controller or driver controller, the traction module 06 is in a power generation state, at which time it can convert mechanical energy into electrical energy, and the traction module 06 can perform kinetic energy recovery.

[0062] Auxiliary load module 04, power battery module 05, and traction module 06 are connected to the output terminal of four-quadrant rectifier module 03. Since these modules are connected to the output terminal of four-quadrant rectifier module 03, when the locomotive is running and its pantograph 01 is raised, traction module 06 and auxiliary load module 04 receive electrical energy from the contact network through pantograph 01 for operation, while power battery module 05 receives electrical energy from the contact network for charging. At this time, because power battery module 05 is connected in parallel with auxiliary load module 04 and traction module 06, the capacitance relationship between auxiliary load module 04, power battery module 05, traction module 06, and traction transformer 02 is: S = S a +S t +S b Where S is the rated capacity of traction transformer 02, S a S is the electrical capacity occupied by auxiliary load module 04 during operation. t S is the capacity occupied by the traction module 06 during operation. b The capacity that the power battery module 05 can occupy when charging can be determined based on the above capacity relationship. t =SS a -S b This corresponds to the maximum charging power obtained when the power battery module 05 is charging. The power topology of the auxiliary load module 04, the power battery module 05, and the traction module 06 is simple, which is beneficial for controlling the charging strategy when the power battery module 05 is charging.

[0063] Furthermore, since the auxiliary load module 04, the power battery module 05, and the traction module 06 are connected to the output terminal of the four-quadrant rectifier module 03, the following charging methods can be included when charging the power battery module 05:

[0064] When the locomotive is running and its pantograph 01 is raised, the traction module 06 and auxiliary load module 04 receive electrical energy from the overhead contact line via the pantograph 01 for operation, while the power battery module 05 receives electrical energy from the overhead contact line for charging. The rated capacity S of the traction transformer 02 and the motor efficiency η of the traction motor in the traction module 06 are obtained. m The mechanical transmission efficiency η of the traction motor t The converter efficiency η of the traction converter in traction module 06 i The remaining capacity S of traction transformer O2 is obtained according to the following relationship. n : Based on the remaining capacity S of traction transformer 02 n and the actual power P of the auxiliary inverter a The following relationship determines the maximum charging power P of the power battery in power battery module 05. b :P b =S n -P a -C. Where C is a constant. The power battery is charged according to its maximum charging power.

[0065] Furthermore, when the locomotive's pantograph 01 is in a lowered state, the electrical energy generated by the traction motor's electric braking can charge the power battery module 05. Since the power battery module 05 is connected in parallel with the auxiliary load module 04 and the traction module 06, the real-time voltage at the output of the four-quadrant rectifier module 03 can be monitored to adjust the charging strategy of the power battery module 05. Charging the power battery module 05 can also include the following charging methods:

[0066] The system acquires the real-time voltage at the output terminal of the four-quadrant rectifier module 03. When the real-time voltage at the output terminal of the four-quadrant rectifier module 03 is less than a first preset threshold, the power battery module 05 supplies power to the locomotive's electrical system. When the real-time voltage at the output terminal of the four-quadrant rectifier module 03 is greater than or equal to the first preset threshold, the power battery module 05 is charged using the electrical energy generated by the electric braking of the traction motor. When the real-time voltage at the output terminal of the four-quadrant rectifier module 03 is greater than or equal to a second preset threshold, a braking resistor module consumes some electrical energy to reduce the real-time voltage at the output terminal of the four-quadrant rectifier module 03. The second preset threshold is greater than or equal to the first preset threshold. Optionally, the first preset threshold is DC 1700V, and the second preset threshold is DC 1850V.

[0067] In the charging strategy of raising the pantograph 01, the power battery module 05 dynamically adjusts its maximum charging power by monitoring the capacity of the auxiliary load module 04 and the traction module 06. Since the power battery module 05 is connected in parallel with the auxiliary load module 04 and the traction module 06, this simple electrical topology simplifies the control of the charging strategy for the power battery module 05. Furthermore, in the charging strategy of lowering the pantograph 01, the parallel connection of the power battery module 05 with the auxiliary load module 04 and the traction module 06 avoids multiple energy transfers for the energy recovered from the kinetic energy of the traction module 06, thus improving charging efficiency.

[0068] This invention provides a locomotive electrical system, comprising: a pantograph controlling the grid connection and disconnection of a traction transformer; the output of the traction transformer being converted to DC power by a four-quadrant rectifier module; an auxiliary load module, a power battery module, and a traction module connected to the output of the four-quadrant rectifier module; the power battery module performing both energy storage and power supply functions; and the traction module supporting both traction and kinetic energy recovery modes. In this locomotive electrical system, the electrical topology is simple, with the auxiliary load module, power battery module, and traction module connected in parallel. Independent operation of these modules facilitates control of the charging strategy, and charging of the locomotive electrical system's power battery is possible even during locomotive operation.

[0069] Based on the above embodiments, Figure 2 This is a schematic diagram of another locomotive electrical system provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the power battery module 05 includes: at least one power battery 501 and at least one bidirectional DC-DC module 502; the power battery 501 and the bidirectional DC-DC module 502 are connected in a one-to-one correspondence; the bidirectional DC-DC module 502 is also connected to the output terminal of at least one four-quadrant rectifier module 03; the power battery 501 is used for energy storage and power supply to the locomotive, and the bidirectional DC-DC module 502 is used for DC step-down.

[0070] Specifically, the power battery 501 is used for energy storage and power supply to the locomotive. When the high-voltage input terminal of the traction transformer 02 is electrically connected to the locomotive's overhead contact line via the raising of the pantograph 01, the power battery 501 receives electrical energy from the overhead contact line for charging. When the high-voltage input terminal of the traction transformer 02 is electrically disconnected from the locomotive's overhead contact line via the lowering of the pantograph 01, the power battery 501 is charged through the kinetic energy recovery of the traction module 06.

[0071] Between the output terminal of the four-quadrant rectifier module 03 and the low-voltage terminal of the power battery 501, the bidirectional DC-DC module 502 is used for bidirectional voltage conversion. When the power battery module 05 is charging, the bidirectional DC-DC module 502 is in a step-down state; when the power battery module 05 is discharging, the bidirectional DC-DC module 502 is in a step-up state, thereby realizing bidirectional energy flow control.

[0072] For example, when the high-voltage input terminal of the traction transformer 02 is electrically connected to the locomotive contact network through the raising of the pantograph 01, the four-quadrant rectifier module 03 outputs DC 1800V, and the bidirectional DC-DC module 502 switches to step-down charging mode. The bidirectional DC-DC module 502 reduces the voltage of the output terminal of the four-quadrant rectifier module 03 to the charging voltage of the power battery 501 to charge the power battery 501. When the high-voltage input terminal of the traction transformer 02 is electrically disconnected from the locomotive contact network through the lowering of the pantograph 01, the output power of the power battery 501 is boosted to DC 1700V by the bidirectional DC-DC module 502 and then output to power the traction module 06 and the auxiliary load module 04.

[0073] Based on the above embodiments, Figure 3 This is a schematic diagram of another locomotive electrical system provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the traction module 06 includes: a braking resistor module 603, a traction converter 601, and at least one traction motor 602; the first end of the traction converter 601 is connected to the output end of at least one four-quadrant rectifier module 03, and the second end of the traction converter 601 is connected to at least one traction motor 602; the output end of the traction converter 601 is connected to the braking resistor module 603; the traction converter 601 is used to step down the voltage between the first end and the second end, and between the second end and the output end; the braking resistor module 603 is used to convert electrical energy into heat energy.

[0074] Specifically, the traction converter 601 performs DC / AC or AC / DC conversion between the output of the four-quadrant rectifier module 03 and the traction motor 602, and directs excess braking energy to the braking resistor module 603 for consumption via its internal chopper circuit. When the traction module 06 is in traction mode, regardless of whether the pantograph 01 is raised or lowered, electrical energy is transmitted from the output of the four-quadrant rectifier module 03 to the traction motor 602. At this time, the traction converter 601 performs DC / AC conversion between the output of the four-quadrant rectifier module 03 and the traction motor 602. The traction converter 601 inverts the DC power from the output of the four-quadrant rectifier module 03 into AC power and supplies it to the traction motor 602. When the traction module 06 is in braking mode, such as when the locomotive uses the brake controller or driver controller to apply electric braking force to the traction module 06, the traction motor 602 is in generating mode. The traction converter 601 is used to perform AC / DC conversion between the output of the four-quadrant rectifier module 03 and the traction motor 602. The traction converter 601 rectifies the AC power from the traction motor 602 into DC power and sends it to the output of the four-quadrant rectifier module 03. The traction motor 602 is used to convert electrical energy into mechanical energy to traction the locomotive or, during electric braking, to convert mechanical energy into electrical energy.

[0075] The braking resistor module 603 is used to convert excess electrical energy output from the traction converter 601 into heat energy for consumption, preventing overvoltage at the output terminal of the four-quadrant rectifier module 03. The traction module 06 can convert mechanical energy into electrical energy to charge the power battery module 05 during braking. When there is excessive braking mechanical energy, the corresponding converted electrical energy is also excessive; therefore, the braking resistor module 603 is set up to consume the excess electrical energy.

[0076] Furthermore, when setting the braking resistor module 603, the charging method for the power battery module 05 can also include the following:

[0077] The real-time voltage at the output terminal of the four-quadrant rectifier module 03 is obtained. When the real-time voltage at the output terminal of the four-quadrant rectifier module 03 is greater than or equal to a second preset threshold, the braking resistor 603 module consumes some electrical energy to reduce the real-time voltage at the output terminal of the four-quadrant rectifier module 03. Optionally, the second preset threshold is DC1850V.

[0078] Based on the above embodiments, Figure 4 This is a schematic diagram of another locomotive electrical system provided in an embodiment of the present invention, as shown below. Figure 4As shown, the auxiliary load module 04 includes at least one first auxiliary load module 401 and at least one second auxiliary load module 402; the input terminals of the first auxiliary load module 401 and the second auxiliary load module 402 are connected to the output terminal of at least one four-quadrant rectifier module 03; the first auxiliary load module 401 is used to supply power to the variable voltage and variable frequency load; the second auxiliary load module 402 is used to supply power to the constant voltage and constant frequency load.

[0079] Specifically, the first auxiliary load module 401 is used to supply power to the variable frequency load. The first auxiliary load module 401 converts the output voltage of the four-quadrant rectifier module 03 into adjustable frequency and voltage AC power. For example, the variable frequency load includes a fan and a compressor.

[0080] The second auxiliary load module 402 is used to supply power to a constant voltage and constant frequency load. The second auxiliary load module 402 converts the output voltage of the four-quadrant rectifier module 03 into AC power. For example, the constant voltage and constant frequency load includes lighting and control power supplies.

[0081] The first auxiliary load module 401 detects the demand of the variable frequency load and dynamically adjusts the frequency and voltage of the output AC power. The second auxiliary load module 402 continuously outputs constant voltage and constant frequency AC power. The input terminals of both are independently connected in parallel to the output terminal of the four-quadrant rectifier module 03, and power is directly drawn from the output terminal of the four-quadrant rectifier module 03 to avoid mutual interference caused by differences in load characteristics.

[0082] Furthermore, the first auxiliary load module 401 includes a variable frequency speed control system. The VVVF (Variable Voltage and Variable Frequency) controlled inverter connects to the motor and achieves constant magnetic flux and motor speed control by simultaneously changing the output frequency and voltage. The second auxiliary load module 402 includes a constant voltage and constant frequency control system. The CVCF (Constant Voltage and Constant Frequency) system maintains a constant output voltage and frequency to supply power to the load.

[0083] Based on the above embodiments, Figure 5 This is a schematic diagram of another locomotive electrical system provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the locomotive electrical system includes: DC bus 07, auxiliary load module 04, power battery module 05 and traction module 06 are respectively connected to DC bus 07, and DC bus 07 is connected to the output terminal of four-quadrant rectifier module 03.

[0084] Specifically, the locomotive electrical system includes a pantograph 01, a traction transformer 02, at least one four-quadrant rectifier module 03, an auxiliary load module 04, a power battery module 05, and a traction module 06. The high-voltage input of the traction transformer 02 is connected to the contact network via the pantograph 01, and the low-voltage output of the traction transformer 02 is connected to the input of the four-quadrant rectifier module 03. A DC bus 07 is established at the output of the four-quadrant rectifier module 03. The high-voltage side of the bidirectional DC-DC module 502 in the auxiliary load module 04 and the DC side of the traction converter 601 in the traction module 06 are all connected to this DC bus 07. In the auxiliary load module 04, the first auxiliary load module 401 supplies power to the variable voltage / variable frequency load, and the second auxiliary load module 402 supplies power to the constant voltage / constant frequency load. The separate first auxiliary load module 401 and second auxiliary load module 402 solve the voltage fluctuation problem caused by the shared AC bus for variable frequency / constant frequency loads. The hardware isolation of the power supply circuits of the first auxiliary load module 401 and second auxiliary load module 402 eliminates mutual interference. In the power battery module 05, the bidirectional DC-DC module 502 is connected to the power battery 501; in the traction module 06, the AC side of the traction converter 601 is connected to the traction motor 602, and the output end of the traction converter 601 is connected to the braking resistor module 603.

[0085] When the pantograph 01 is raised, the overhead contact line power is stepped down by the traction transformer 02 and rectified by the four-quadrant rectifier module 03 into DC 1800V DC power, which is then output to the DC bus. The traction converter 601 draws power from the DC bus 07 to drive the traction motor 602 to pull the locomotive. At the same time, the bidirectional DC-DC module 502 dynamically adjusts the charging power according to the remaining capacity of the transformer to charge the power battery 501. The first auxiliary load module 401 and the second auxiliary load module 402 independently supply power to the load. When the pantograph 01 is lowered and the locomotive brakes, the power generated by the traction motor 602 is rectified by the traction converter 601 and fed back to the DC bus 07. When the voltage of the DC bus 07 is greater than or equal to DC 1700V, the bidirectional DC-DC module 502 is triggered to charge the power battery 501. If the voltage of the DC bus 07 is greater than or equal to DC 1850V, the traction converter 601 conducts the chopper circuit to dissipate energy in the braking resistor module 603. The auxiliary load module 04, the power battery module 05, and the traction module 06 are connected to the direct-connected DC bus 06. The electrical topology is simple, enabling charging according to the remaining capacity of the traction transformer 02 during traction operation and charging triggered by the voltage threshold during braking operation.

[0086] Figure 6 This is a flowchart illustrating a locomotive power supply control method provided in an embodiment of the present invention. This embodiment is applicable to dynamic charging situations of locomotives, and the method can be applied to the locomotive electrical system in any embodiment of the present invention. Figure 6 As shown, the locomotive power supply control method includes:

[0087] S101. When the locomotive's pantograph is in the raised state, obtain the traction power of the traction motor in the traction module and the actual power of the auxiliary inverter in the auxiliary load module.

[0088] Specifically, traction power refers to the real-time output power of the traction motor in traction module 06 at a specific traction level, reflecting the current traction energy consumption of the locomotive. For example, the current traction level of the locomotive can be obtained, and the traction power can be determined based on the locomotive's traction level.

[0089] The actual power of the auxiliary inverter refers to the measured power at the output terminal of the inverter in the auxiliary load module 04. It can be calculated based on the output voltage / current of the inverter in the auxiliary load module 04, reflecting the real-time energy consumption of the auxiliary load module 04.

[0090] The power battery module 05 is connected in parallel with the auxiliary load module 04 and the traction module 06. Therefore, the capacitance relationship between the auxiliary load module 04, the power battery module 05, the traction module 06, and the traction transformer 02 includes: S = S a +S t +S b Where S is the rated capacity of traction transformer 02, S a S is the electrical capacity occupied by auxiliary load module 04 during operation. t S is the capacity occupied by the traction module 06 during operation. b The capacity that the power battery module 05 can occupy when charging can be determined based on the above capacity relationship, and the maximum charging power of the power battery module 05 during charging can be obtained accordingly.

[0091] S102. Determine the maximum charging power of the power battery in the power battery module based on the traction power and the actual power of the auxiliary inverter.

[0092] Specifically, as mentioned above, since the power battery module 05 is connected in parallel with the auxiliary load module 04 and the traction module 06, the capacitance relationship between the auxiliary load module 04, the power battery module 05, the traction module 06, and the traction transformer 02 is: S = S a -S t -S b .

[0093] Correspondingly, the remaining capacity S of the traction transformer 02 can be calculated by considering the capacitance relationship between the auxiliary load module 04, the power battery module 05, and the traction module 06 and the traction transformer 02. n The remaining capacity of traction transformer 02 can be considered as the electrical capacity that can be occupied when power battery module 05 is charging and auxiliary load module 04 is driving the load. Therefore, in the remaining capacity S of traction transformer 02... nSubtract the actual power P of the auxiliary inverter a Then, the maximum charging power P of the power battery was obtained. b .

[0094] S103. Charge the power battery according to its maximum charging power.

[0095] Specifically, the power battery module 05 calculates the maximum charging power P of the power battery. b The maximum charging current is obtained, and a judgment is made based on the battery's allowable charging current. The smaller value is then used for PI control of the power battery module 05 to charge the power battery. This locomotive power supply control method of the present invention uses closed-loop control of the charging current of the power battery module 05 to ensure precise matching of the actual charging power without exceeding the battery's safety threshold, thus ensuring efficient and stable charging and preventing battery overcurrent damage.

[0096] The locomotive dynamic charging method proposed in this invention involves: real-time acquisition of traction and auxiliary power during pantograph raising to dynamically calculate the maximum battery charging power; utilizing the maximum battery charging power in a closed-loop manner to perform charging control, thereby achieving dynamic charging of the power battery under traction conditions, maximizing charging during running time and reducing charging time during downtime; simultaneously, combining the transformer capacity to obtain charging power ensures system safety and prevents disruption to the operation of other components during charging.

[0097] Based on the above embodiments, Figure 7 A flowchart of another locomotive power supply control method provided in an embodiment of the present invention is shown below. Figure 7 As shown, the locomotive power supply control method includes:

[0098] S201. When the locomotive's pantograph is in the raised state, obtain the traction power of the traction motor in the traction module and the actual power of the auxiliary inverter in the auxiliary load module.

[0099] S202. Obtain the rated capacity of the traction transformer, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module.

[0100] Specifically, the rated capacity S of the traction transformer refers to the maximum designed output power of the traction transformer 02, which is determined by the equipment specifications; the motor efficiency η of the traction motor... m The electrical energy to mechanical energy conversion efficiency of the traction motor in traction module 06, and the mechanical transmission efficiency η. t The mechanical loss rate of transmission components such as the gearbox in the traction module 06, and the converter efficiency η of the traction converter. iThis refers to the conversion efficiency of the traction converter in traction module 06. These efficiency parameters are all measured or preset values ​​under real-time operating conditions, used to measure the energy loss of the traction link in the computer-controlled vehicle.

[0101] S203. Determine the remaining capacity of the traction transformer based on the rated capacity of the traction transformer, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module.

[0102] The relationship between the remaining capacity of the traction transformer and its rated capacity, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module includes: Among them, S n S represents the remaining capacity of the traction transformer, S represents the rated capacity of the traction transformer, and η represents the remaining capacity of the traction transformer. m η is the motor efficiency of the traction motor. t η is the mechanical transmission efficiency of the traction motor. i For the converter efficiency of the traction converter, P n The traction power of the traction motor.

[0103] Specifically, based on the relationship between the remaining capacity of the traction transformer and its rated capacity, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module, the remaining capacity of transformer 02 that can be allocated to non-traction loads under the current operating conditions is obtained. Based on the remaining capacity S of traction transformer 02... n Dynamically allocate charging power.

[0104] S204. Determine the maximum charging power of the power battery based on the remaining capacity of the traction transformer and the actual power of the auxiliary inverter.

[0105] The relationship between the maximum charging power of the power battery and the remaining capacity of the traction transformer and the actual power of the auxiliary inverter includes: P b =S n -P a -C; where P a To assist the actual power of the inverter, P b C represents the maximum charging power of the power battery, and C is a constant.

[0106] Specifically, the maximum charging power P of the power battery b Through formula P b =S n -P a -C determined. From the remaining capacity S of traction transformer 02. nThe system prioritizes the auxiliary load power in auxiliary load module 04, then deducts a safety margin to arrive at the maximum battery charging power. This enables real-time optimization of charging power allocation and dynamic adjustment of energy distribution among the traction, auxiliary, and charging systems.

[0107] For example, refer to Figure 5 The provided structural diagram of the locomotive electrical system, such as Figure 5 As shown, under locomotive traction conditions, if the traction level is obtained as 6, then the corresponding traction power P of traction motor 602 is... n The rated capacity is 900kW; S is the rated capacity of traction transformer 02, such as 2500kVA; the efficiency η of traction motor 602 is... m Taking 92%, the mechanical transmission efficiency η of traction motor 602 is... t Taking 97.5%, the converter efficiency η of traction converter 601 is... i Taking 98%, the remaining capacity S of traction transformer 02 is... n It is 1476kVA.

[0108] according to Figure 5 From the electrical topology, it can be seen that the three bidirectional DC-DC modules 502 are grouped together and are independent of each other, corresponding to ACU1 and ACU2 respectively. If the actual power of the first auxiliary load module 401 corresponding to ACU1 is 50kW, then the total maximum charging power P of the three power batteries 501 is... b The result is 1476 / 2-50-100=588kW.

[0109] Based on this, the combined maximum charging power P of the three power batteries 501 is obtained. b It is 588kW.

[0110] S205. Charge the power battery according to its maximum charging power.

[0111] Based on the above embodiments, Figure 8 A flowchart of another locomotive power supply control method provided in an embodiment of the present invention is shown below. Figure 8 As shown, the locomotive power supply control method includes:

[0112] S301. When the locomotive's pantograph is in the raised state, obtain the traction power of the traction motor in the traction module and the actual power of the auxiliary inverter in the auxiliary load module.

[0113] S302. Obtain the rated capacity of the traction transformer, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module.

[0114] S303. Determine the remaining capacity of the traction transformer based on the rated capacity of the traction transformer, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module.

[0115] S304. Determine the maximum charging power of the power battery based on the remaining capacity of the traction transformer and the actual power of the auxiliary inverter.

[0116] S305. Obtain the maximum charging current of the power battery based on the maximum charging power of the power battery.

[0117] Specifically, the maximum charging current of the power battery in power battery module 05 is determined by the maximum charging power P of the power battery. b It is calculated by dividing by the rated voltage of power battery 501.

[0118] S306. Determine the relationship between the maximum charging current of the power battery and the allowable charging current of the power battery, and perform proportional-integral control on the power battery module in the locomotive electrical system to charge it with the minimum current value.

[0119] Specifically, the allowable charging current of the power battery in power battery module 05 refers to the safe charging current threshold of the battery. By comparing the maximum charging current and the allowable charging current, the smaller value is selected as the current setpoint for proportional-integral (PI) control. The switching duty cycle of the bidirectional DC-DC module in power battery module 05 is dynamically adjusted through a PI closed-loop algorithm, ensuring that the actual charging current accurately tracks the setpoint and resolving the current oscillation problem caused by load fluctuations during charging. Optionally, the allowable charging current of the power battery can be dynamically determined by parameters such as battery temperature and state of charge.

[0120] Based on the above embodiments, Figure 9 A flowchart of another locomotive power supply control method provided in an embodiment of the present invention is shown below. Figure 9 As shown, the locomotive power supply control method includes:

[0121] S401. When the locomotive's pantograph is in the raised state, obtain the traction power of the traction motor in the traction module and the actual power of the auxiliary inverter in the auxiliary load module.

[0122] S402. Determine the maximum charging power of the power battery in the power battery module based on the traction power and the actual power of the auxiliary inverter.

[0123] S403. Charge the power battery according to its maximum charging power.

[0124] S404. When the locomotive's pantograph is in the lowered state, the power battery module is charged using the electrical energy generated by the electric braking of the traction motor.

[0125] Specifically, when the locomotive applies braking force using the brake controller or driver controller, the traction motor in traction module 06 is in generator mode, converting mechanical energy into electrical energy. The traction inverter in traction module 06 rectifies the electrical energy generated by the traction motor and transmits it to the intermediate DC bus. At this time, since the pantograph 01 is not raised, the four-quadrant rectifier 03 stops working, and excess electrical energy is dissipated by charging the auxiliary load module 04, the power battery module 05, and the heat generated by the braking resistor in traction module 06.

[0126] Optionally, the voltage value of the DC bus is detected, and the power battery module 05 is automatically switched to charging mode based on the voltage value of the DC bus. Braking energy is recovered to the power battery 501. When the voltage value of the DC bus exceeds a threshold, energy is dissipated through the braking resistor module in the traction module 06, thus realizing the recovery of braking energy during pantograph lowering.

[0127] Furthermore, when the locomotive's pantograph is in a lowered state, the position of the different brake controllers is converted into an electric braking level, and different electric braking forces are applied according to the electric braking level. When the actual electric braking force is less than the set electric braking force, the air braking system is controlled to automatically apply a certain amount of air braking to supplement the braking force, ensuring that the locomotive can apply a sufficient amount of braking force.

[0128] Based on the above embodiments, Figure 10 The flowchart illustrates another locomotive power supply control method provided in an embodiment of the present invention. In the locomotive electrical system, the locomotive electrical system includes a DC bus, and auxiliary load modules, power battery modules, and traction modules are respectively connected to the output terminals of a four-quadrant rectifier module via the DC bus. Figure 10 As shown, the locomotive power supply control method includes:

[0129] S501. When the locomotive's pantograph is in the raised state, obtain the traction power of the traction motor in the traction module and the actual power of the auxiliary inverter in the auxiliary load module.

[0130] S502. Determine the maximum charging power of the power battery in the power battery module based on the traction power and the actual power of the auxiliary inverter.

[0131] S503. Charge the power battery according to its maximum charging power.

[0132] S504. Obtain the real-time voltage of the DC bus. When the real-time voltage of the DC bus is less than the first preset threshold, the power battery module supplies power to the locomotive electrical system. When the real-time voltage of the DC bus is greater than or equal to the first preset threshold, the power battery module is charged using the electrical energy generated by the electric braking of the traction motor. When the real-time voltage of the DC bus is greater than or equal to the second preset threshold, the braking resistor module consumes part of the electrical energy to reduce the real-time voltage of the DC bus. The second preset threshold is greater than or equal to the first preset threshold.

[0133] Specifically, the real-time voltage of the DC bus refers to the measured voltage value at the output terminal of the four-quadrant rectifier module 03. The first preset threshold is the voltage critical point that triggers the charging of the power battery in the power battery module 05, and the second preset threshold is the overvoltage protection point that activates the braking resistor module in the traction module 06. Both are preset fixed values ​​and satisfy the condition that the second threshold is greater than or equal to the first threshold.

[0134] By acquiring and comparing the real-time voltage of the DC bus, the braking energy intensity can be quantified in real time, and energy scheduling priority can be achieved through voltage level division. When the DC bus voltage is less than a first preset threshold, the power battery in the power battery module 05 discharges to supply power. When the DC bus voltage is greater than or equal to the first preset threshold, braking energy charging is initiated. When the DC bus voltage is greater than or equal to a second preset threshold, the resistor module in the braking traction module 06 consumes energy to prevent overvoltage. The locomotive power supply control method provided in this embodiment of the invention automatically switches between three working modes through a voltage threshold mechanism to solve the dynamic balance problem between energy recovery and system safety under braking conditions. Optionally, the first preset threshold is DC1700V; the second preset threshold is DC1850V.

[0135] For example, when the locomotive is not raised and is powered by the power battery in power battery module 05, the DC bus voltage is DC1700V. When the traction motor in traction module 06 provides electric braking to the DC bus, causing the DC bus voltage to exceed DC1700V, the bidirectional DC-DC module in power battery module 05 switches from discharge mode to charging mode. The charging current does not exceed the allowable charging current of the power battery in power battery module 05. When the DC bus voltage continues to rise, it indicates that there is too much energy, which cannot be completely consumed by simply charging the power battery. When the DC bus voltage rises to DC1850V, the traction converter in traction module 06 steps down the voltage, and the excess energy is consumed by the heat generated by the braking resistor in traction module 06. This enables dynamic charging of the power battery in electric braking mode and ensures that the excess energy after the power battery is fully charged is consumed by the heat generated by the braking resistor, so that the locomotive's braking force can always be maintained without interruption.

[0136] In the locomotive power supply control method provided in this embodiment of the invention, power supply, charging and energy consumption are carried out based on three-level threshold control of DC bus voltage, which maximizes the recovery of braking energy and ensures system safety.

[0137] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0138] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A locomotive electrical system, characterized in that, include: The pantograph, traction transformer, at least one four-quadrant rectifier module, at least one auxiliary load module, at least one power battery module, and at least one traction module; The high-voltage input terminal of the traction transformer is electrically connected to the locomotive contact network through the raising of the pantograph, or electrically disconnected from the locomotive contact network through the lowering of the pantograph. The input terminal of the four-quadrant rectifier module is connected to the low-voltage output terminal of the traction transformer; the four-quadrant rectifier module is used for four-quadrant rectification. The auxiliary load module, the power battery module, and the traction module are each connected to the output terminal of at least one of the four-quadrant rectifier modules; The auxiliary load module includes the auxiliary load of the locomotive; the power battery module is used for energy storage and power supply to the locomotive; the traction module is used for traction of the locomotive and / or kinetic energy recovery.

2. The locomotive electrical system according to claim 1, characterized in that, The power battery module includes: at least one power battery and at least one bidirectional DC-DC module; The power battery is connected to the bidirectional DC-DC module in a one-to-one correspondence; the bidirectional DC-DC module is also connected to the output terminal of at least one of the four-quadrant rectifier modules; The power battery is used for energy storage and power supply to the locomotive, and the bidirectional DC-DC module is used for DC step-down.

3. The locomotive electrical system according to claim 1, characterized in that, The traction module includes: a braking resistor module, a traction converter, and at least one traction motor; The first end of the traction converter is connected to the output end of at least one of the four-quadrant rectifier modules, and the second end of the traction converter is connected to at least one of the traction motors. The output terminal of the traction converter is connected to the braking resistor module; The traction converter is used to step down the voltage between the first and second terminals and between the second terminal and the output terminal; the braking resistor module is used to convert electrical energy into heat energy.

4. The locomotive electrical system according to claim 1, characterized in that, The auxiliary load module includes: at least one first auxiliary load module and at least one second auxiliary load module; The input terminals of the first auxiliary load module and the second auxiliary load module are connected to the output terminal of at least one of the four-quadrant rectifier modules; The first auxiliary load module is used to supply power to the variable voltage and variable frequency load; the second auxiliary load module is used to supply power to the constant voltage and constant frequency load.

5. The locomotive electrical system according to claim 1, characterized in that, Also includes: The DC bus is connected to the auxiliary load module, the power battery module and the traction module respectively, and the DC bus is connected to the output terminal of the four-quadrant rectifier module.

6. A locomotive power supply control method, applied to the locomotive electrical system of any one of claims 1-5, characterized in that, include: When the locomotive's pantograph is in the raised position, the traction power of the traction motor in the traction module and the actual power of the auxiliary inverter in the auxiliary load module are obtained. The maximum charging power of the power battery in the power battery module is determined based on the traction power and the actual power of the auxiliary inverter. The power battery is charged according to its maximum charging power.

7. The locomotive power supply control method according to claim 6, characterized in that, Determining the maximum charging power of the power battery in the power battery module based on the traction power and the actual power of the auxiliary inverter includes: Obtain the rated capacity of the traction transformer, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module. The remaining capacity of the traction transformer is determined based on the rated capacity of the traction transformer, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module. The maximum charging power of the power battery is determined based on the remaining capacity of the traction transformer and the actual power of the auxiliary inverter. The relationship between the remaining capacity of the traction transformer and its rated capacity, the motor efficiency of the traction motor, the mechanical transmission efficiency of the traction motor, and the converter efficiency of the traction converter in the traction module includes: Among them, S n S represents the remaining capacity of the traction transformer, S represents the rated capacity of the traction transformer, and η represents the remaining capacity of the traction transformer. m η is the motor efficiency of the traction motor. t η is the mechanical transmission efficiency of the traction motor. i For the converter efficiency of the traction converter, P n The traction power of the traction motor; The relationship between the maximum charging power of the power battery, the remaining capacity of the traction transformer, and the actual power of the auxiliary inverter includes: P b =S n -P a -C; Among them, P a To assist the actual power of the inverter, P b C represents the maximum charging power of the power battery, and C is a constant.

8. The locomotive power supply control method according to claim 7, characterized in that, The charging of the power battery according to its maximum charging power includes: The maximum charging current of the power battery is obtained based on the maximum charging power of the power battery. The relationship between the maximum charging current of the power battery and the allowable charging current of the power battery is determined, and proportional-integral control is performed on the power battery module in the locomotive electrical system to charge it with the minimum current value.

9. The locomotive power supply control method according to claim 6, characterized in that, The traction module includes: a braking resistor module, a traction converter, and at least one traction motor; the locomotive power supply control method includes: When the locomotive's pantograph is in the lowered state, the electrical energy generated by the electric braking of the traction motor is used to charge the power battery module.

10. The locomotive power supply control method according to claim 9, characterized in that, The locomotive electrical system includes a DC bus, and the auxiliary load module, the power battery module, and the traction module are respectively connected to the output terminal of the four-quadrant rectifier module through the DC bus; the charging of the power battery module using the electrical energy generated by the electric braking of the traction motor includes: The real-time voltage of the DC bus is obtained, and when the real-time voltage of the DC bus is less than a first preset threshold, the power battery module supplies power to the locomotive electrical system. When the real-time voltage of the DC bus is greater than or equal to the first preset threshold, the power battery module is charged using the electrical energy generated by the electric braking of the traction motor. When the real-time voltage of the DC bus is greater than or equal to the second preset threshold, the braking resistor module consumes part of the electrical energy to reduce the real-time voltage of the DC bus. The second preset threshold is greater than or equal to the first preset threshold.

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