Novel auxiliary storage battery traction control strategy

Abstract

The invention relates to a novel auxiliary storage battery traction control strategy which comprises the following steps: 1) judging a traction condition for starting an auxiliary storage battery, and judging whether to start the auxiliary storage battery for traction according to train state information; and 2) judging the traction direction of the auxiliary storage battery, calculating and determining a direction selection point according to the preset bidirectional traction of the storage battery to minimize the energy consumption of the storage battery, running the running direction selection point of the train, and judging the traction running direction of the storage battery by the TCMS according to a certain condition. And (3) finally, auxiliary storage battery traction is executed, and when the distance between the train and the target rescue point is smaller than the preset distance, train braking is applied to enable the train to stop at the target rescue point. According to the invention, by constructing a perfect control strategy, accurate control of the traction process of the storage battery is realized, the operation efficiency is improved, and the operation safety of the train is greatly guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of urban rail transit train control, and in particular to a novel auxiliary battery traction control strategy. Background Art

[0002] In the rail transit sector, battery traction technology is gradually emerging as a key solution to vehicle operation issues under specific operating conditions. Currently, auxiliary battery traction is primarily used in depot or warehouse traction scenarios, which are often located on straight tracks and place relatively basic control requirements. Speed ​​limits are typically set at a low speed of approximately 5 km / h, and the control strategy does not employ specialized algorithms or logic, remaining a simple speed control mode.

[0003] During mainline operations, when a grid voltage fault or a fault in the train's high-voltage power supply circuit occurs, auxiliary battery traction is used to tow the train a short distance to a nearby station. However, in this application scenario, the train's operating speed is also controlled within a low speed range of approximately 5km / h to 10km / h. While this low-speed operation mode ensures train mobility in emergency situations to a certain extent, it also leads to low operational efficiency. Furthermore, the current control methods for mainline battery traction remain simple, lacking a comprehensive and detailed control strategy to optimize the entire traction process.

[0004] The battery-powered traction system for electric rail vehicles developed by Zhuzhou Times boasts unique technical implementation features. The system emphasizes its hardware architecture, utilizing specific hardware configurations to implement the battery-powered traction function. Data acquisition is also designed to capture critical data during system operation in real time. Clear regulations define the activation and deactivation conditions for battery traction, ensuring the system activates and deactivates the function at appropriate times. Furthermore, the system considers the relationship between battery charge and traction power output, dynamically adjusting traction power based on the remaining battery charge. However, regarding battery traction control, the system only specifies a speed limit of 50 km / h; traction is discontinued when the train speed reaches this limit.

[0005] The core of the emergency traction and auxiliary battery system for rail transit launched by Beijing Jiaotong New Energy lies in the system implementation method and the design of battery health and safety monitoring. The system is committed to building a reliable emergency traction and auxiliary power supply solution, and through specific technical means, it ensures that the battery can operate stably in emergency situations. During the system implementation process, a series of advanced technologies and algorithms were used to ensure the efficient operation of the battery. At the same time, through real-time monitoring of battery health and safety, potential problems can be discovered in a timely manner and corresponding measures can be taken. However, similar to the system of Zhuzhou Times, this system of Beijing Jiaotong New Energy does not involve the specific battery traction control strategy during line operation, and lacks in-depth discussion on how to achieve efficient and stable battery traction under different line conditions and different operating conditions.

[0006] In summary, while battery traction technology has made some progress in practical applications, significant deficiencies remain in its control strategies. To further enhance the effectiveness of battery traction in rail transit, a battery traction control strategy that comprehensively considers factors such as train speed, track gradient and curvature, and battery charge is urgently needed. Summary of the Invention

[0007] The object of the present invention is to provide a battery traction control strategy with high traction speed and capable of adopting different traction strategies for different road sections.

[0008] In a first aspect, the present application provides a novel auxiliary battery traction control strategy, including:

[0009] Determine the conditions for starting the auxiliary battery for traction, and decide whether to start the auxiliary battery for traction based on the train status information;

[0010] Determine the auxiliary battery traction direction based on the positional relationship between the train and the preset direction selection point;

[0011] To perform auxiliary battery traction:

[0012] The battery continues to pull the train until the train speed reaches the first speed. When the train speed exceeds the first speed, the battery traction is cut off, the train enters the coasting state and the train speed is continuously monitored.

[0013] When the train's coasting speed is less than the first operating speed, battery traction is applied;

[0014] When the train's coasting speed is greater than or equal to the first operating speed, the battery traction is cut off;

[0015] When the train coasting speed is greater than the second operating speed, applying train brakes;

[0016] When the train coasting speed is less than or equal to the second operating speed, the train brake is removed;

[0017] The second running speed is greater than the first running speed; when the distance from the train to the target rescue point is less than a preset distance, the train brake is applied to make the train stop at the target rescue point.

[0018] To be more specific, the train status information includes: train network voltage status, train high-speed circuit breaker status, train high-voltage transfer switch status, train traction inverter status, train TCMS status, battery BMS status, battery voltage, and train speed.

[0019] More specifically, after determining the traction direction, if the traction direction is different from the train's forward direction, the train end-changing operation strategy is initiated.

[0020] More specifically, the train braking is electric braking or hydraulic braking.

[0021] More specifically, the auxiliary battery traction process also includes: when the train is electrically braked, controlling the traction motor to charge the battery.

[0022] More specifically, during the battery charging process, when the battery voltage reaches a maximum voltage or the battery SOC reaches a preset SOC, the battery overvoltage protection strategy is activated.

[0023] More specifically, the auxiliary battery traction process also includes: the train BMS monitors the battery discharge voltage and controls the battery charge and discharge voltage not to exceed a preset discharge voltage limit value.

[0024] More specifically, the auxiliary battery traction process further includes: monitoring the remaining battery power, and if the remaining battery power is lower than a preset limit power, exiting the battery traction.

[0025] More specifically, the train braking adopts partial maximum braking force.

[0026] In a second aspect, the present application also provides a novel auxiliary battery traction control device, comprising: a memory for storing a computer program; a processor for executing the computer program and implementing the novel auxiliary battery traction control strategy.

[0027] The beneficial effects of the present invention are:

[0028] 1) The battery traction control strategy designed in this application can adopt different traction control according to the different traction conditions, coasting conditions, and braking conditions during actual line operation, such as: uphill, downhill, and straight road. The train is controlled to have different speed ranges under different road conditions, providing comprehensive and multi-angle safety guarantees for the train to reach the rescue point faster.

[0029] 2) When battery traction is applied, electric braking energy can be fed back to the battery for energy storage, saving energy and preventing the risk of battery traction affecting train traction. This application achieves precise control of the battery traction process by constructing a comprehensive control strategy, improving operational efficiency and greatly ensuring train operation safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the battery traction control strategy of this application.

[0031] Figure 2 This is a schematic diagram of the "direction selection point" settings for the uplink and downlink lines. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the following describes the specific embodiments of the present invention in a clear and complete manner. It should be understood that the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0033] During train operation, when a grid voltage failure or a train high-voltage power supply circuit failure occurs, the train will lose power. It is of great significance to install an auxiliary battery in the train for train traction in emergency situations. However, the existing battery traction does not have a specific control strategy for line operation, or the control is simple, only satisfying the train running in a predetermined direction. The present invention proposes a new battery traction control strategy. In order to save energy, the train can run in both directions on the line, and control the train speed to increase without excessively consuming battery power, and run safely to the next station or rescue point, thereby improving passenger comfort and traction efficiency, and being able to respond more quickly to emergencies such as grid voltage failures that affect train operation.

[0034] like Figure 1 As shown, the novel auxiliary battery traction control strategy designed in this application includes:

[0035] Determines the conditions for activating the auxiliary battery traction and determines whether to activate the auxiliary battery for traction based on train status information. The TCMS (Train Control and Management System) issues a battery traction command only when the following train status information is met, controlling the closing of the battery traction contactor and preparing the battery for traction. Train status information includes: no grid voltage or simultaneous failure of both high-speed circuit breakers; the high-voltage transfer switch is in the "Run" position; the train traction inverter is fault-free; the train TCMS is fault-free; the battery BMS is fault-free; the battery voltage is greater than the traction voltage; and the train speed is zero.

[0036] Based on the pre-set battery bidirectional traction to minimize energy consumption, determine the direction selection point between the two rescue points. At this direction selection point, the battery energy consumed by the train to reach the two rescue points is the same. A transponder or magnet is pre-set at the direction selection point, or the location information of the direction selection point is directly stored in a specific storage area of ​​the TCMS. Figure 2 As shown, the safe operation of a train can be divided into up or down (both the up and down lines are equipped with direction selection points, which can be located at the same or different locations). The TCMS determines the train's running distance in real time. When the train passes a direction selection point between two stations, the direction selection point is marked as 1. If the train fails to run, the traction direction must be determined before battery traction is activated. If the signal is 1, the traction direction is determined to be forward. If the signal is not 1, the traction direction is determined to be backward, and the train starts to change ends. When the train reaches the next station, the signal of Mark 1 is cleared and the marking is re-determined.

[0037] After determining the auxiliary battery traction direction, start auxiliary battery traction:

[0038] During operation, the train battery system status is further monitored. The battery discharge voltage and temperature are tested to determine whether the battery is functioning normally and whether it meets the traction conditions. This helps prevent abnormal train traction caused by battery anomalies and ensures the stability of the battery traction system.

[0039] The battery continues to pull the train until the train reaches a first operating speed. When the train speed exceeds the first operating speed, the battery is disconnected and the train enters a coasting state. During the coasting state, the train's speed may vary depending on different road conditions (e.g., uphill, downhill, and flat roads), and the speed may increase or decrease. In a further improvement of the present invention, to improve train operating efficiency and conserve auxiliary battery power, the train's speed is continuously monitored and different traction control methods are used for different speed variations:

[0040] When the train is running on a straight or uphill section, it will gradually slow down. If the coasting speed is detected to be less than the first operating speed, battery traction will be applied to increase the train speed. If the coasting speed is detected to be greater than or equal to the first operating speed, battery traction will be cut off to save battery power.

[0041] When a train is running on a downhill section, it may gradually accelerate. If the coasting speed is detected to be increasing from the first operating speed to a speed greater than the second operating speed, the train brakes are applied promptly to ensure train safety and prevent the train from continuing to accelerate and running too fast. If the coasting speed is detected to be less than or equal to the second operating speed, the train brakes are removed to ensure the train runs at a faster speed.

[0042] Battery traction is implemented, and the train's operating speed is continuously monitored. The aforementioned traction control strategy is selected based on the train's operating conditions. When the distance from the train to the target rescue point is less than a preset distance, the train brakes are applied to ensure the train finally and smoothly stops at the target rescue point. In further improvements, as the train approaches the target rescue point, the braking procedure is initiated in advance when the distance to the target rescue point (a preset distance that can be set based on the train's braking distance characteristics, such as 200 meters) is reached. A graded braking strategy can be used, with pre-braking initially at 30% of maximum braking force, increasing to 60% at 100 meters from the target point, and then applying 100% braking force for the final 50 meters, achieving a smooth and precise stop at the train's precise distance.

[0043] During battery traction, the BMS (Battery Management System) continuously monitors the battery discharge current, controls the battery discharge voltage, and calculates the battery's State of Charge (SOC) to ensure it does not exceed the discharge voltage and SOC limits. If the battery discharge voltage approaches the voltage limit, the system reduces the battery's output power or immediately shuts down the battery. During traction, the system monitors the battery temperature in real time. If the temperature exceeds a preset value, it activates air or liquid cooling. If the temperature is too high, it also reduces power, limiting the traction power to a preset range to ensure the battery maintains safe operation during traction.

[0044] The train can brake using either electric or hydraulic braking. Depending on the difference between the actual train speed and the preset speed, a portion of the maximum braking force can be applied. For example, 1 / 3, 1 / 2, or 2 / 3 of the maximum normal braking force can be applied. When electric braking is used, the energy fed back from the traction motor is controlled to charge the battery. When the battery reaches its maximum voltage or the SOC reaches 100%, an overvoltage resistor is activated to protect the battery from overcharging. When purely hydraulic braking is used, there is no electric braking and the battery is not charged. The BMS monitors the battery discharge current and voltage to ensure they do not exceed the limit.

[0045] The control logic for the auxiliary battery traction control strategy designed in this application is implemented by the train control system (TCMS). The program is stored in the TCMS memory, and its internal logic control unit outputs control commands, which are then executed by the train's traction and braking system. The battery status is monitored by the battery management system (BMS) and transmitted to the TCMS via a network bus, such as an MVB.

[0046] In some specific embodiments, the train is equipped with two batteries with a total capacity of 200Ah. The battery traction strategy is pre-set at a first operating speed of 5km / h and a second speed of 35km / h, enabling the train to operate on a maximum slope of 45%. During the initial battery traction process, the train speed is brought to 5km / h, after which traction is removed and the train enters coasting mode. During coasting mode, the system continuously monitors the train speed. If the coasting speed is less than 5km / h, traction is applied to compensate for the lost speed. If the coasting speed exceeds 35km / h, half the maximum service brake is applied (to prevent excessive braking current and battery charging current from damaging the battery) to prevent the train from running too fast. If the train speed is less than 35km / h during braking, the brakes are promptly removed. If the speed is less than 5km / h, traction is applied. The control system monitors the train speed in real time and applies different control strategies based on the speed until the train is within a preset distance of 200m from the target rescue point, at which point the train brakes are applied to ensure a smooth stop at the target rescue point.

[0047] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations of these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

Claims

1. A new auxiliary battery traction control strategy, characterized in that: include: Determine the conditions for starting the auxiliary battery for traction, and decide whether to start the auxiliary battery for traction based on the train status information; Determine the auxiliary battery traction direction based on the positional relationship between the train and the preset direction selection point; To perform auxiliary battery traction: The battery continues to pull the train until the train speed reaches the first speed. When the train speed exceeds the first speed, the battery traction is cut off, the train enters the coasting state and the train speed is continuously monitored. When the train's coasting speed is less than the first operating speed, battery traction is applied; When the train's coasting speed is greater than or equal to the first operating speed, the battery traction is cut off; When the train coasting speed is greater than the second operating speed, applying train brakes; When the train coasting speed is less than or equal to the second operating speed, the train brake is removed; The second running speed is greater than the first running speed; when the distance from the train to the target rescue point is less than a preset distance, the train brake is applied to make the train stop at the target rescue point.

2. The auxiliary battery traction control strategy according to claim 1, characterized in that: The train status information includes: train network voltage status, train high-speed circuit breaker status, train high-voltage transfer switch status, train traction inverter status, train TCMS status, battery BMS status, battery voltage, and train speed.

3. The auxiliary battery traction control strategy according to claim 1, characterized in that: After determining the traction direction, if the traction direction is different from the train's forward direction, the train end-changing operation strategy is activated.

4. The auxiliary battery traction control strategy according to claim 1, characterized in that: The train brake is electric brake or hydraulic brake.

5. The auxiliary battery traction control strategy according to claim 4, characterized in that: The auxiliary battery traction process also includes: when the train is electrically braked, controlling the traction motor to charge the battery.

6. The auxiliary battery traction control strategy according to claim 5, characterized in that: During the battery charging process, when the battery voltage reaches the maximum voltage or the battery SOC reaches a preset SOC, the battery overvoltage protection strategy is activated.

7. The auxiliary battery traction control strategy according to claim 1, characterized in that: The auxiliary battery traction process also includes: the train BMS monitors the battery discharge voltage and controls the battery charge and discharge voltage not to exceed the preset discharge voltage limit value.

8. The auxiliary battery traction control strategy according to claim 1, characterized in that: The auxiliary battery traction process also includes: monitoring the remaining battery power, and if the remaining battery power is lower than a preset limit power, exiting the battery traction.

9. The auxiliary battery traction control strategy according to claim 1, characterized in that: The train braking adopts part of the maximum braking force.

10. A new auxiliary battery traction control device, characterized in that: include: memory for storing computer programs; A processor is configured to execute the computer program and implement the novel auxiliary battery traction control strategy according to any one of claims 1 to 9.

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