Control method and control device for power supply circuit of dual-power locomotive

Abstract

The invention discloses a control method and a control device for a dual-power locomotive power supply circuit. The dual-power locomotive power supply circuit comprises a first battery pack, a second battery pack and a switching module, the first battery pack and the second battery pack are respectively connected with the first load and the second load through the switching module; the control method comprises the following steps: acquiring first residual electric quantity of a first battery pack and second residual electric quantity of a second battery pack; when it is determined that the difference value between the first residual electric quantity and the second residual electric quantity is larger than a preset threshold value, a switching module is controlled to switch power supplies of the first load and the second load to the battery pack with the high residual electric quantity; and continuously acquiring the residual electric quantity of the two battery packs, and when the difference value between the first residual electric quantity and the second residual electric quantity is reduced to a balance threshold value, restoring the initial power supply mode. The problem of battery pack life imbalance caused by load characteristic difference in a fixed power supply mode can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of locomotive power battery control, and particularly relates to a control method and a control device of a dual-power locomotive power supply circuit. BACKGROUND

[0002] In a dual-source locomotive power supply system, a grouping battery architecture is usually adopted to drive different loads of the locomotive. However, due to the essential difference in power consumption characteristics of different loads of the locomotive, for example, the energy consumption imbalance between a variable frequency variable voltage load and a constant frequency constant voltage load, the actual discharge rates of the two groups of batteries are different.

[0003] The prior art adopts a fixed power supply mode (i.e., each group of batteries only supplies power to a specified load), and after long-term operation, the battery group of the high-load loop is in a deep discharge state for a long time, and the capacity attenuation is significantly faster than that of the low-load loop battery group, thereby affecting the overall life of the power battery. SUMMARY

[0004] The present application provides a control method and a control device of a dual-power locomotive power supply circuit to solve the problem of battery group life imbalance caused by the difference in load characteristics in the fixed power supply mode.

[0005] In a first aspect, the embodiments of the present application provide a control method of a dual-power locomotive power supply circuit, characterized in that the dual-power locomotive power supply circuit comprises a first battery group, a second battery group and a switching module; the first battery group and the second battery group are connected with a first load and a second load through the switching module; the control method comprises: acquiring a first residual capacity of the first battery group and a second residual capacity of the second battery group; when it is determined that the difference between the first residual capacity and the second residual capacity is greater than a preset threshold, controlling the switching module to switch the power supply source of the first load and the second load to the battery group with higher residual capacity; continuously acquiring the residual capacities of the two battery groups, and when the difference between the first residual capacity and the second residual capacity decreases to an equalization threshold, restoring the initial power supply mode.

[0006] Optionally, the switching module comprises: a first contactor for controlling the first battery group to supply power to the first load; a second contactor for controlling the second battery group to supply power to the second load; and a third contactor for controlling the first battery group to supply power to the second load.

[0007] Optionally, when it is determined that the difference between the first residual capacity and the second residual capacity is greater than the preset threshold, the step of controlling the switching module to switch the power supply source of the first load and the second load to the battery group with higher residual capacity comprises: when it is determined that the difference between the first residual capacity and the second residual capacity is greater than the preset threshold, opening the second contactor and closing the third contactor, so that the first battery group supplies power to the first load and the second load at the same time.

[0008] Optionally, when the difference between the first residual capacity and the second residual capacity falls to the equalization threshold, the step of resuming the initial power supply mode comprises: continuously acquiring the residual capacities of the two battery groups, and when the difference between the first residual capacity and the second residual capacity falls to the equalization threshold, disconnecting the third contactor and closing the second contactor.

[0009] Optionally, the preset threshold is 5% of the second residual capacity.

[0010] Optionally, the equalization threshold is that the first residual capacity is equal to the second residual capacity.

[0011] Optionally, the first load is a variable frequency and variable voltage load, and the second load is a constant frequency and constant voltage load.

[0012] Optionally, before the step of acquiring the first residual capacity of the first battery group and the second residual capacity of the second battery group, the method comprises: detecting the first residual capacity and the second residual capacity in real time by the capacity detection module.

[0013] In a second aspect, an embodiment of the present application provides a control device of a dual-power locomotive power supply circuit, comprising: a capacity detection module, configured to detect a first residual capacity of a first battery group and a second residual capacity of a second battery group in real time; and a processing module, connected with the capacity detection module, configured to execute the control method provided by any embodiment of the present application.

[0014] Optionally, the processing module comprises a microprocessor.

[0015] The control method of the dual-power locomotive power supply circuit provided by the embodiment of the present application solves the problem of unbalanced battery group life caused by the difference in load characteristics under the fixed power supply mode by dynamically adjusting the power supply mode of the dual-power locomotive. Specifically, the residual capacities of the first battery group and the second battery group are acquired in real time first, and when the difference between the residual capacities of the two battery groups is greater than a preset threshold, the power supply sources of the first load and the second load are switched to the battery group with higher residual capacity by the switching module, so that the battery group with lower residual capacity stops discharging to reduce consumption. Then, the residual capacities of the two battery groups are continuously monitored, and when the difference between the two residual capacities falls to an equalization threshold, the initial power supply mode (i.e., the two battery groups supply power to the corresponding loads respectively) is resumed by the switching module. Through this dynamic switching, the over-discharge of a certain battery group due to long-term bearing of higher load is avoided, so as to balance the consumption of the two battery groups and prolong the overall service life.

[0016] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to make the technical solution in the embodiments of the present application clearer, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0018] Figure 1 is a structural schematic diagram of a dual-power locomotive power supply circuit provided by an embodiment of the present application;

[0019] Figure 2 is a flow chart of a control method of a dual-power locomotive power supply circuit provided by an embodiment of the present application;

[0020] Figure 3 is a flow chart of another control method of a dual-power locomotive power supply circuit provided by an embodiment of the present application;

[0021] Figure 4 is a flow chart of a control method of a dual-power locomotive power supply circuit provided by an embodiment of the present application;

[0022] Figure 5 is a structural schematic diagram of a control device of a dual-power locomotive power supply circuit provided by an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to make the technical solution in the embodiments of the present application clearer, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0024] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or a chronological sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] In order to solve the prior art problems, the embodiment of the present application provides a control method and a control device for a dual-power locomotive power supply circuit. Figure 1 is a structural schematic diagram of a dual-power locomotive power supply circuit provided by the embodiment of the present application. Figure 1 As shown in the figure, the dual-power locomotive power supply circuit comprises a first battery pack 11, a second battery pack 12 and a switching module 13; the first battery pack 11 and the second battery pack 12 are connected with a first load 10 and a second load 20 respectively through the switching module 13.

[0026] Specifically, the first battery pack 11 is one of the core power supply sources of the locomotive, and is mainly responsible for supplying power to the first load 10 in the initial power supply mode, and the state of its electric quantity is monitored in real time through the residual electric quantity detection.

[0027] The second battery pack 12 is another group of energy storage devices parallel to the first battery pack 11, and is also a core power supply source of the locomotive, and mainly supplies power to the second load 20 in the initial state, and the residual electric quantity thereof is also detected in real time for comparison with the electric quantity of the first battery pack 11.

[0028] The switching module 13 is a key component for realizing the switching of the power supply circuit, and can comprise a plurality of contactors. By controlling the closing and opening of the contactors, the connection relationship between the battery pack and the load can be changed, so that the switching of the power supply source is realized, and the load is switched to the battery pack with higher electric quantity when needed.

[0029] The first load 10 is part of the electric equipment of the locomotive, and can be a variable frequency and variable voltage load. The power consumption of this kind of load changes with the working condition, such as the change of power consumption when the motor speed is adjusted.

[0030] The second load 20 is another part of the electric equipment of the locomotive, and can be a constant frequency and constant voltage load, and its power consumption is relatively stable, such as lighting and ventilation equipment.

[0031] Figure 2 is a flowchart of a control method for a dual-power locomotive power supply circuit provided by the embodiment of the present application. The method of the embodiment can be executed by a processing module, which can be realized in the form of software and / or hardware, and can be integrated on devices such as vehicle-mounted equipment and electric tools. Figure 2 As shown in the figure, the control method comprises:

[0032] S101, acquiring a first residual electric quantity of a first battery pack and a second residual electric quantity of a second battery pack.

[0033] The first residual capacity and the second residual capacity respectively represent the proportion of the current stored capacity of the two different battery packs to the total capacity of the respective battery pack. Assuming that the total capacity of the first battery pack 11 is 100 Ah and the current residual capacity is 50 Ah, the first residual capacity is 50 Ah; similarly, if the total capacity of the second battery pack 12 is 80 Ah and the residual capacity is 32 Ah, the second residual capacity is 32 Ah. These capacity values are the key basis for judging the power supply capacity and the capacity balance state of the battery pack.

[0034] In some embodiments, the first residual capacity and the second residual capacity are detected in real time by a capacity detection module. The capacity detection module is connected to the first battery pack 11 and the second battery pack 12 respectively, can continuously collect the capacity data (such as voltage, current, capacity attenuation coefficient, etc.) of the two battery packs, and calculate the first residual capacity and the second residual capacity based on a preset algorithm. The detected first residual capacity and second residual capacity will be transmitted to the processing module.

[0035] In some embodiments, a high-precision capacity sensor, such as a current sensor and a voltage sensor based on the Hall effect, is connected in series on the output circuit of each battery pack. These sensors can measure the current and voltage values of the battery pack output in real time. At the same time, the output end of the sensor is connected to the analog input interface of the battery management system (BMS), ensuring that the data can be transmitted to the BMS. For example, in a energy storage power station, each battery pack is equipped with an independent capacity sensor to transmit data to the BMS for unified processing.

[0036] The BMS runs a special capacity monitoring algorithm internally. The current and voltage data transmitted by the capacity sensor are collected at a fixed time interval (such as 1 second), the capacity change of the battery pack in that time period is calculated through integral operation (coulomb counting method), and the initial capacity of the battery pack is combined to update the first residual capacity and the second residual capacity values in real time. For example, in the battery management system of a mobile phone, the residual capacity is calculated by continuously collecting battery voltage and current and displayed on the screen using an algorithm.

[0037] S102, when it is determined that the difference between the first residual capacity and the second residual capacity is greater than a preset threshold, the control switching module switches the power supply source of the first load and the second load to the battery pack with higher residual capacity.

[0038] The processing module determines whether the difference between the remaining power of the two battery groups is greater than a preset threshold value. When it is detected that the difference between the first remaining power and the second remaining power is greater than the preset threshold value (such as 5% of the second remaining power), and the first battery group 11 has higher power, the power supply circuit of the second battery group 12 to the second load 20 is cut off, so that the second battery group 12 stops supplying power to the second load 20; the power supply circuit of the first battery group 11 to the second load 20 is turned on, and the original power supply circuit of the first battery group 11 to the first load 10 is combined, so that the first battery group 11 supplies power to the first load 10 and the second load 20 at the same time. Through the above operation, the first battery group 11 with higher remaining power undertakes the power supply task of all loads, and the second battery group 12 with lower remaining power stops discharging, so that the difference between the power of the two battery groups gradually decreases (the high-power battery group consumes faster due to the increase in power supply, and the low-power battery group maintains the power due to the stop of discharging), thereby laying a foundation for subsequent recovery of the initial mode. If the second battery group 12 has higher remaining power, the logic is similar, and the embodiments of the present application will not be described here. Optionally, the preset threshold value is 5% of the second remaining power.

[0039] S103, continuously acquiring the remaining power of the two battery groups, and when the difference between the first remaining power and the second remaining power decreases to an equalization threshold value, the initial power supply mode is restored.

[0040] Continuous acquisition: by means of a power detection module and the like, the process of constantly measuring and reading the remaining power values of the two battery groups at certain time intervals (such as every second or every few minutes). The purpose is to track the power state of the battery group in real time, and to provide the latest data support for subsequent power difference judgment and power supply mode adjustment.

[0041] The difference decreases to the equalization threshold value: during the use of the battery group, due to factors such as load power consumption, the power of the two battery groups will gradually differ. When the difference between the first remaining power and the second remaining power decreases to the pre-set equalization threshold value, it indicates that the power difference between the two battery groups has decreased to an acceptable equalization range. For example, the equalization threshold value is set to 0, and when the first remaining power is 40 Ah and the second remaining power is 40%, the difference 0 reaches the equalization threshold value.

[0042] When the processing module determines that the difference decreases to the equalization threshold value, the processing module sends a control signal to the switching module. The signal is transmitted to the control circuit of the switching module 13 through a digital communication interface (such as SPI, I2C). After receiving the control signal, the switching module 13 changes the circuit connection mode by controlling the action of internal relays, contactors or power switch tubes and the like, and restores to the initial power supply mode.

[0043] Resuming the initial power supply mode: the system returns to the initially set power supply mode. In the initial power supply mode, the two battery packs respectively undertake the power supply task of specific loads, for example, the first battery pack 11 is dedicated to power supply for the vehicle, and the second battery pack 12 is dedicated to power supply for the in-vehicle lighting and entertainment system. When the difference in the residual power of the two battery packs meets the condition, the mode is resumed, and the normal and stable power supply architecture of the system can be maintained.

[0044] The control method of the dual-power locomotive power supply circuit provided by the embodiment of the application solves the problem of unbalanced service life of the battery packs caused by the difference in load characteristics in the fixed power supply mode by dynamically adjusting the power supply mode of the dual-power locomotive. Specifically, the residual power of the first battery pack and the second battery pack is first acquired in real time, and when the difference in the residual power of the two battery packs is greater than a preset threshold, the power supply source of the first load and the second load is switched to the battery pack with higher residual power by the switching module, so that the battery pack with lower residual power stops discharging to reduce consumption. Then, the residual power of the two battery packs is continuously monitored, and when the difference between the two is reduced to an equalization threshold, the initial power supply mode (i.e., the two battery packs supply power to the corresponding loads, respectively) is restored by the switching module. Through this dynamic switching, the over-discharge of a certain battery pack caused by long-term bearing of higher load is avoided, thereby balancing the consumption of the two battery packs and prolonging the overall service life.

[0045] Optionally, with reference back to Figure 1 , the switching module 13 comprises: a first contactor KM1 configured to control the first battery pack 11 to supply power to the first load 10; a second contactor KM2 configured to control the second battery pack 12 to supply power to the second load 20; and a third contactor KM3 configured to control the first battery pack 11 to supply power to the second load 20.

[0046] Optionally, the dual-power locomotive power supply circuit further comprises a first auxiliary converter 14 and a second auxiliary converter 15, the output end of the first battery pack 11 is connected to the first end of the first auxiliary converter 14, and the second end of the first auxiliary converter 14 is connected to the first load 10 through the first contactor KM1.

[0047] The output end of the second battery pack 12 is connected to the first end of the second auxiliary converter 15, and the second end of the second auxiliary converter 15 is connected to the second load 20 through the second contactor KM2.

[0048] Optionally, the first load 10 is a variable-frequency variable-voltage load, and the second load 20 is a constant-frequency constant-voltage load.

[0049] Figure 3 is another flowchart of the control method of the dual-power locomotive power supply circuit provided by the embodiment of the application. As shown in Figure 3 , the control method comprises:

[0050] S201, acquire the first residual capacity of the first battery pack and the second residual capacity of the second battery pack.

[0051] S202, when it is determined that the difference between the first residual capacity and the second residual capacity is greater than a preset threshold, disconnect the second contactor and close the third contactor, so that the first battery pack simultaneously supplies power to the first load and the second load.

[0052] Specifically, when it is detected that the difference between the first residual capacity of the first battery pack and the second residual capacity of the second battery pack exceeds a preset threshold (such as 5% of the second residual capacity), the processing module will perform two key actions: one is to disconnect the second contactor KM2, cutting off the power supply circuit of the second battery pack 12 to the second load 20, so that the second battery pack 12 stops supplying power to the second load 20; the second is to close the third contactor KM3, connecting the power supply circuit of the first battery pack 11 to the second load 20. At this time, combined with the originally closed first contactor KM1, the first battery pack 11 ultimately realizes simultaneous power supply to the first load 10 and the second load 20. The purpose of this operation is to let the first battery pack 11 with higher residual capacity undertake the power supply task of all loads, and the second battery pack 12 with lower residual capacity stops discharging, so as to gradually reduce the difference in capacity between the two battery packs, avoid the low-capacity battery pack from being further discharged due to continuous discharge, and achieve the effect of balancing the service life of the battery packs.

[0053] S203, continuously acquire the residual capacity of the two battery packs, and when the difference between the first residual capacity and the second residual capacity decreases to an equalization threshold, disconnect the third contactor and close the second contactor.

[0054] Specifically, the equalization threshold is that the first residual capacity is equal to the second residual capacity. That is, when it is continuously monitored that the first residual capacity of the first battery pack is equal to the second residual capacity of the second battery pack, the processing module will perform two key actions: one is to disconnect the third contactor KM3, cutting off the power supply circuit of the first battery pack 11 to the second load 20; the second is to close the second contactor KM2, reconnecting the power supply circuit of the second battery pack 12 to the second load 20. Through this operation, the power supply mode returns to the initial state, that is, the first battery pack 11 only supplies power to the first load 10, and the second battery pack 12 only supplies power to the second load 20. The purpose is to return to the mode of independently supplying power to the corresponding load after the capacity of the two battery packs is balanced, which not only guarantees the stability of the load power supply, but also maintains the balanced state of the two battery packs, avoids new capacity imbalance caused by long-term single-group power supply, and prolongs the overall service life of the battery packs.

[0055] Figure 4 is a flowchart of another control method of a dual-power locomotive power supply circuit provided by an embodiment of the present application. As shown in Figure 4 , the control method comprises:

[0056] S301, detecting the first residual power and the second residual power in real time through an electric quantity detection module.

[0057] Specifically, the electric quantity detection module is connected with the first battery pack and the second battery pack respectively, can continuously collect the electric quantity related data (such as voltage, current, etc.) of the two battery packs, and calculate the first residual power of the first battery pack and the second residual power of the second battery pack based on a preset algorithm.

[0058] S302, obtaining the first residual power of the first battery pack and the second residual power of the second battery pack.

[0059] S303, when it is determined that the difference between the first residual power and the second residual power is greater than a preset threshold, disconnecting the second contactor and closing the third contactor, so that the first battery pack supplies power to the first load and the second load at the same time.

[0060] S304, continuously obtaining the residual power of the two battery packs, and when the difference between the first residual power and the second residual power decreases to an equalization threshold, disconnecting the third contactor and closing the second contactor.

[0061] Based on the same inventive concept, the embodiment of the present application also provides a control device of a dual-power locomotive power supply circuit, Figure 5 is a structural schematic diagram of a control device of a dual-power locomotive power supply circuit provided by the embodiment of the present application. As Figure 5 shown, the control device comprises: an electric quantity detection module 100, configured to detect the first residual power of the first battery pack and the second residual power of the second battery pack in real time; and a processing module 200 connected with the electric quantity detection module 100, configured to execute the control method provided by any embodiment of the present application. Optionally, the processing module 200 comprises a microprocessor. The control device provided by the embodiment of the present application has the same beneficial effects as the control method, and the same parts will not be described here.

[0062] It should be understood that the various forms of flow shown above can be reordered, added or deleted. For example, each step described in the present application can be executed in parallel, sequentially or in different order, as long as the desired results of the technical solutions of the present application can be achieved, and the present application does not limit here.

[0063] The above specific embodiments do not constitute a limitation on the protection scope of the present application. 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 modification, equivalent replacement and improvement within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A control method for a dual power locomotive power supply circuit, comprising: The dual-power locomotive power supply circuit comprises a first battery pack, a second battery pack and a switching module; the first battery pack and the second battery pack are connected with a first load and a second load respectively through the switching module; The control method comprises: acquiring a first residual capacity of the first battery pack and a second residual capacity of the second battery pack; when it is determined that the difference between the first residual capacity and the second residual capacity is greater than a preset threshold, controlling the switching module to switch the power supply source of the first load and the second load to the battery pack with higher residual capacity; continuously acquiring the residual capacities of the two battery packs, and when the difference between the first residual capacity and the second residual capacity decreases to an equalization threshold, restoring the initial power supply mode.

2. The control method of a dual power locomotive power supply circuit according to claim 1, characterized by, The switching module comprises: a first contactor for controlling the first battery pack to supply power to the first load; a second contactor for controlling the second battery pack to supply power to the second load; a third contactor for controlling the first battery pack to supply power to the second load.

3. The control method of a dual power locomotive power supply circuit according to claim 2, characterized by, The step of, when it is determined that the difference between the first residual capacity and the second residual capacity is greater than a preset threshold, controlling the switching module to switch the power supply source of the first load and the second load to the battery pack with higher residual capacity, comprises: when it is determined that the difference between the first residual capacity and the second residual capacity is greater than a preset threshold, opening the second contactor and closing the third contactor, so that the first battery pack supplies power to the first load and the second load at the same time.

4. The control method of a dual power locomotive power supply circuit according to claim 3, characterized by, The step of continuously acquiring the residual capacities of the two battery packs, and when the difference between the first residual capacity and the second residual capacity decreases to an equalization threshold, restoring the initial power supply mode, comprises: continuously acquiring the residual capacities of the two battery packs, and when the difference between the first residual capacity and the second residual capacity decreases to an equalization threshold, opening the third contactor and closing the second contactor.

5. The control method of a dual power locomotive power supply circuit according to claim 1, characterized by, The preset threshold is 5% of the second residual capacity.

6. The control method of a dual power locomotive power supply circuit according to claim 1, characterized by, The equalization threshold is that the first residual capacity is equal to the second residual capacity.

7. The control method of a dual power locomotive power supply circuit according to claim 1, characterized by, The first load is a variable frequency and variable voltage load, and the second load is a constant frequency and constant voltage load.

8. The control method of a dual power locomotive power supply circuit according to claim 1, characterized by, Before the step of acquiring the first residual capacity of the first battery pack and the second residual capacity of the second battery pack, the method comprises:

9. A control for a dual power locomotive power supply circuit, comprising: real-time detecting the first residual capacity and the second residual capacity by a capacity detection module. comprises: a capacity detection module for real-time detecting a first residual capacity of a first battery pack and a second residual capacity of a second battery pack; 10. The control for dual power locomotive supply circuit of claim 9 wherein, a processing module connected with the capacity detection module, configured to execute the control method in any one of claims 1-9. The processing module comprises a microprocessor.

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