A ground-based energy storage method for traction power supply and braking energy recovery

Abstract

This invention discloses a ground-based energy storage method for traction power supply braking energy recovery, comprising the following steps: Step 1, ground system construction; Step 2, grid connection; Step 3, braking process analysis; Step 4, energy recovery; Step 5, voltage regulation; Step 6, storage and retrieval. This invention utilizes an ordered battery pack in the energy storage unit to store energy and alternates between charging and discharging operations through cyclic discharge, reducing damage to the energy storage unit during charging and discharging and extending the service life of the energy storage batteries. A detection unit monitors the train's operating status, and when the train is in a stable braking state, the return line is connected to adjust the energy conversion process between the traction network and the train's pantograph, ensuring the smoothness of the charging and discharging conversion and guaranteeing the power supply stability of the train's internal circuits. By adjusting the resistance value in the compensation circuit, the difference in input voltage is compensated, preventing deviations between the charging voltage and the preset value, thereby improving the practicality of the energy storage method.

Description

Technical Field

[0001] This invention relates to the field of traction train braking energy recovery technology, specifically a ground-based energy storage method for traction power supply braking energy recovery. Background Technology

[0002] Rail trains, capable of carrying large numbers of passengers, play a vital role in urban transportation. Urban rail trains are characterized by short station intervals, high train density, and high voltage and current consumption, necessitating the use of traction power recovery to store energy generated during braking. While existing traction power recovery storage methods can generally meet daily needs, they still have certain shortcomings. First, the capacitors in existing traction power recovery storage methods, acting as independent storage and discharge structures, also discharge as power supply units during energy recovery, accelerating charging and discharging losses and shortening the lifespan of the energy storage components. Second, existing traction power recovery storage methods cannot connect the return circuit of the recovered energy according to the train's running status, making it difficult to ensure the smoothness of the converter's charging and discharging conversion, affecting the power supply stability of the train's internal circuitry. Third, existing traction power recovery storage methods cannot regulate the charging voltage of the power supply during energy storage, affecting the method's practicality. Therefore, designing a ground-based energy storage method for traction power braking energy recovery is essential. Summary of the Invention

[0003] The purpose of this invention is to provide a ground-based energy storage method for traction power supply braking energy recovery, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a ground-based energy storage method for traction power supply braking energy recovery, comprising the following steps: Step 1, ground system construction; Step 2, grid connection; Step 3, braking process analysis; Step 4, energy recovery; Step 5, voltage regulation; Step 6, storage and retrieval;

[0005] In step one above, a power supply unit is built at the center of the train track, and power is supplied to the train on the rail through the power supply unit. A charging and discharging unit and an energy storage unit are set up next to the track, and an anti-electric fence is set up for enclosure and protection.

[0006] In step two above, the charging and discharging unit is connected to the power supply unit, and a detection unit is set up on the train so that the detection unit is connected to the return line control in the power supply unit.

[0007] In step three above, the train's operating status is detected by a detection unit, and the return line is connected when the train is in a stable braking state.

[0008] In step four above, the current flowing out of the return network enters the charge-discharge unit, and then the charge-discharge unit sequentially stores the electrical energy in the ordered battery pack in the energy storage unit.

[0009] In step five above, during the process of the charging and discharging unit supplying power to the energy storage unit, the magnitude of the current in the circuit is detected, and the input voltage of the energy storage unit is adjusted according to the magnitude of the current.

[0010] In step six above, the electrical energy stored in the energy storage unit is transmitted to the power grid as needed, and the amount of transmission is recorded by the electricity meter.

[0011] Preferably, in step one, the power supply unit consists of a traction substation, a contact network, a track circuit, and a return line. The contact network is slidably connected to the pantograph at the bottom of the train to supply power to the train; the charging / discharging unit and the energy storage unit are electrically connected.

[0012] Preferably, in step two, the power supply unit consists of a DC-DC converter. During charging, the current flows from the return line into the energy storage unit, and during discharging, the current flows from the energy storage unit into the contact network.

[0013] Preferably, in step two, the operation process of the power supply unit is as follows: first, rectification is performed through a three-way transformer, then IC filtering is performed, transmission is performed after filtering, IC filtering is performed again after transmission, and then the power supply unit is converted into the input energy of the traction motor through an inverter.

[0014] Preferably, in step three, the process of detecting the train's operating status is as follows: First, the attitude data of the train is received through the attitude sensor, and at the same time, the real-time speed of the train is received by the speed sensor. Then, the acceleration of the train is analyzed based on the real-time speed. Subsequently, the train's driving status is analyzed by combining the attitude data and the real-time acceleration. When the attitude data is horizontally stable and the acceleration is less than the train's driving threshold, the train is determined to be in a braking state. Then, the status in the interval time unit is continuously detected. When the braking state is observed for ten consecutive time intervals, the train is determined to be in a stable braking state.

[0015] Preferably, in step four, the ordered battery packs in the energy storage unit are sequentially arranged inside the structural frame of the energy storage unit and connected through a shunt regulator. The shunt regulator is used to detect the state of charge inside the battery packs. The charging cycle of the battery packs is sequential, charging from the lowest sequence and repeating in this cycle. Discharging starts from the lowest sequence and discharges sequentially, with charging and discharging occurring simultaneously. The sequence number of the charging battery pack is 'a', and the number of charging cycles for 'a' is 'n'. The sequence number of the discharging battery pack is 'b', and the number of discharging cycles for 'b' is 'm'. Then, when n = m, a > b; when n = m + 1, a > b. <b。

[0016] Preferably, in step five, the process of adjusting the input voltage of the energy storage unit according to the current magnitude is as follows: first, the input current is transferred to the standard load circuit, then the voltage data in the load circuit is detected in real time, and then the resistance value in the compensation circuit is adjusted to compensate for abnormal differences in the input voltage through the change in resistance.

[0017] Compared with the prior art, the beneficial effects of this invention are as follows: This ground-based energy storage method for traction power supply braking energy recovery utilizes an ordered battery pack in the energy storage unit to store energy, and alternates between charging and discharging operations through cyclic discharge, reducing damage to the energy storage unit during charging and discharging and extending the service life of the energy storage battery; the detection unit monitors the train's operating status, and when the train is in a stable braking state, the return line is connected to adjust the energy conversion process between the traction network and the train's pantograph, ensuring the smoothness of the converter's charging and discharging conversion and guaranteeing the power supply stability of the train's internal circuits; during the energy recovery and charging process, the resistance value in the compensation circuit is adjusted to compensate for the input voltage difference, avoiding deviations between the charging voltage and the preset value, thereby improving the practicality of the energy storage method. Attached Figure Description

[0018] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0020] Please see Figure 1 The present invention provides an embodiment of a ground-based energy storage method for traction power supply braking energy recovery, comprising the following steps: Step 1, ground system construction; Step 2, grid connection; Step 3, braking process analysis; Step 4, energy recovery; Step 5, voltage regulation; Step 6, storage and retrieval.

[0021] In step one above, a power supply unit is built at the center of the train track, and power is supplied to the train on the rails through the power supply unit. The power supply unit consists of a traction substation, a contact network, a track circuit, and a return line. The contact network is slidably connected to the pantograph at the bottom of the train to supply power to the train. A charging and discharging unit and an energy storage unit are set up next to the track, and the charging and discharging unit and the energy storage unit are electrically connected. An anti-electric fence is set up for enclosure and protection.

[0022] In step two above, the charging and discharging unit is connected to the power supply unit, which consists of a DC-DC converter. During charging, the current flows from the return line into the energy storage unit, and during discharging, the current flows from the energy storage unit into the contact network. A detection unit is installed on the train, and the detection unit is connected to the return line in the power supply unit. The operation process of the power supply unit is as follows: first, the current is rectified by a three-way transformer, then IC filtering is performed, the current is transmitted after filtering, IC filtering is performed again after transmission, and then the current is converted into the input energy of the traction motor by an inverter.

[0023] In step three above, the train's operating status is detected by a detection unit. The process of detecting the train's operating status is as follows: First, the attitude sensor receives the train's attitude data, and the speed sensor receives the train's real-time speed. Then, the train's acceleration is analyzed based on the real-time speed. Subsequently, the train's driving status is analyzed by combining the attitude data and real-time acceleration. When the attitude data is stable and the acceleration is less than the train's travel threshold, the train is determined to be in a braking state. Then, the status in the interval time unit is continuously detected. When ten consecutive time intervals are in a braking state, the train is determined to be in a stable braking state. When the train is in a stable braking state, the return line is connected.

[0024] In step four above, the current flowing from the return network enters the charging / discharging unit, which then sequentially stores electrical energy in ordered battery packs within the energy storage unit. These ordered battery packs are arranged sequentially within the energy storage unit's structural frame and connected via a shunt regulator. The shunt regulator detects the state of charge within the battery packs. The charging cycle of the battery packs is sequential, starting with the lowest sequence number and continuing in this cycle. Similarly, during discharging, the lowest sequence number is used for sequential discharge. Charging and discharging occur simultaneously. The sequence number of the charging battery pack is 'a', and the number of charging cycles for 'a' is 'n'. The sequence number of the discharging battery pack is 'b', and the number of discharging cycles for 'b' is 'm'. Therefore, when n = m, a > b; when n = m + 1, a > b. <b;

[0025] In step five above, during the process of the charging and discharging unit supplying power to the energy storage unit, the current in the circuit is detected and the input voltage of the energy storage unit is adjusted according to the current. The process of adjusting the input voltage of the energy storage unit according to the current is as follows: first, the input current is transferred to the standard load circuit, then the voltage data in the load circuit is detected in real time, and then the resistance value in the compensation circuit is adjusted to compensate for the abnormal difference in the input voltage through the change in resistance.

[0026] In step six above, the electrical energy stored in the energy storage unit is transmitted to the power grid as needed, and the amount of transmission is recorded by the electricity meter.

[0027] Based on the above, the advantages of this invention are as follows: This invention utilizes an ordered battery pack in the energy storage unit to store energy and alternates between charging and discharging operations through cyclic discharge, reducing damage during charging and discharging and extending the service life of the energy storage battery; a detection unit monitors the train's operating status, and when the train is in a stable braking state, the return line is connected to adjust the energy conversion process between the traction network and the train's pantograph, ensuring the smoothness of the converter's charging and discharging and guaranteeing the power supply stability of the train's internal circuits; during the energy recovery and charging process, the resistance value in the compensation circuit is adjusted to compensate for the input voltage difference, preventing deviations between the charging voltage and the preset value, thereby improving the practicality of the energy storage method.

[0028] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for ground-based energy storage for traction power supply braking energy recovery, comprising the following steps: Step 1: Ground system setup; Step 2: Power grid connection; Step 3: Braking process analysis; Step 4: Energy recovery; Step 5: Voltage regulation; Step 6: Storage and retrieval; Its features include: In step one above, a power supply unit is built at the center of the train track, and power is supplied to the train on the rail through the power supply unit. A charging and discharging unit and an energy storage unit are set up next to the track, and an anti-electric fence is set up for enclosure and protection. In step two above, the charging and discharging unit is connected to the power supply unit, and a detection unit is set up on the train so that the detection unit is connected to the return line control in the power supply unit. In step three above, the train's operating status is detected by a detection unit. When the train is in a stable braking state, the return line is connected. The process of detecting the train's operating status is as follows: First, the attitude sensor receives the train's attitude data, and the speed sensor receives the train's real-time speed. Then, the train's acceleration is analyzed based on the real-time speed. Subsequently, the train's driving status is analyzed by combining the attitude data and the real-time acceleration. When the attitude data is horizontally stable and the acceleration is less than the train's travel threshold, the train is determined to be in a braking state. Then, the status in the interval time unit is continuously detected. When ten consecutive time intervals are in a braking state, the train is determined to be in a stable braking state. In step four above, the current flowing out of the return network enters the charging and discharging unit, which then sequentially stores electrical energy in the ordered battery packs within the energy storage unit. The ordered battery packs are arranged sequentially within the structural frame of the energy storage unit and connected via a shunt regulator. The shunt regulator detects the state of charge within the battery packs. The charging cycle of the battery packs is sequential, starting with the lowest sequence number and continuing in this cycle. Discharging also starts with the lowest sequence number and continues in this cycle. Charging and discharging occur simultaneously. The sequence number of the charging battery pack is 'a', and the number of charging cycles for 'a' is 'n'. The sequence number of the discharging battery pack is 'b', and the number of discharging cycles for 'b' is 'm'. Therefore, when n = m, a > b; when n = m + 1, a > b. <b; In step five above, during the process of the charging and discharging unit supplying power to the energy storage unit, the magnitude of the current in the circuit is detected, and the input voltage of the energy storage unit is adjusted according to the magnitude of the current. In step six above, the electrical energy stored in the energy storage unit is transmitted to the power grid as needed, and the amount of transmission is recorded by the electricity meter.

2. The ground-based energy storage method for traction power supply and braking energy recovery according to claim 1, characterized in that: In step one, the power supply unit consists of a traction substation, a contact network, a track circuit, and a return line. The contact network is slidably connected to the pantograph at the bottom of the train to supply power to the train. The charging and discharging unit and the energy storage unit are electrically connected.

3. The ground-based energy storage method for traction power supply and braking energy recovery according to claim 1, characterized in that: In step two, the power supply unit consists of a DC-DC converter. During charging, the current flows from the return line into the energy storage unit, and during discharging, the current flows from the energy storage unit into the contact network.

4. A ground-based energy storage method for traction power supply and braking energy recovery according to claim 1, characterized in that: In step two, the operation of the power supply unit is as follows: first, the power is rectified by a three-way transformer, then filtered by an IC, then transmitted, then filtered again by an IC, and finally converted into the input energy of the traction motor by an inverter.

5. A ground-based energy storage method for traction power supply and braking energy recovery according to claim 1, characterized in that: In step five, the process of adjusting the input voltage of the energy storage unit according to the current magnitude is as follows: first, the input current is transferred to the standard load circuit, then the voltage data in the load circuit is detected in real time, and then the resistance value in the compensation circuit is adjusted to compensate for the abnormal difference in the input voltage through the change in resistance.

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