Energy management method and device of train traction power supply system, and readable storage medium

Abstract

The application discloses a kind of energy management method and device of train traction power supply system, readable storage medium, comprising: obtaining the traction load power of train traction power supply system belonging train at target time, the energy supply parameter of multi-source energy supply equipment, the energy storage parameter of energy storage equipment, energy supply parameter includes the output power of regenerative energy equipment in multi-source energy supply equipment at target time, energy storage parameter includes the capacity of electrolytic cell, ammonia synthesis device in energy storage equipment;Based on traction load power, energy supply parameter, energy storage parameter and the power balance constraint condition of train traction power supply system, with the maximum of target function corresponding to the overall energy yield of train traction power supply system as optimization target, predict the working power of electrolytic cell and ammonia synthesis device at target time, target function is based on the mathematical model and yield, cost of energy supply equipment and energy storage equipment at corresponding time and construction;Based on the working power of electrolytic cell and ammonia synthesis device at target time, the energy management of this system is executed.

Description

Technical Field

[0001] This application relates to the fields of electrical engineering and rail transit technology, and in particular to an energy management method and device for a train traction power supply system, as well as a readable storage medium. Background Technology

[0002] Traditional train traction power supply systems are highly dependent on the power grid. To reduce the cost of purchasing electricity from the grid, deploying distributed renewable energy equipment such as wind power and photovoltaics along railway lines or at traction substations, and configuring supporting energy storage systems such as batteries, has become a key direction for energy conservation and emission reduction in train traction power supply systems.

[0003] However, the renewable energy generated by renewable energy equipment is subject to temporal and spatial fluctuations. For example, wind power systems generate wind power when there is wind in the environment, and photovoltaic systems generate photovoltaic power when there is sunlight during the day. If a train passes the location of renewable energy equipment at night or when there is no wind, the power consumed by the train's traction load cannot be provided by the renewable energy source at that location.

[0004] This results in a mismatch between the spatiotemporal fluctuations of renewable energy and the fluctuations of train traction load. While energy storage devices can recover renewable energy and use it to supply power when trains pass, thus playing a role in peak shaving and valley filling to some extent, existing energy storage devices have limited capacity and cannot fundamentally solve the spatiotemporal mismatch. Therefore, this characteristic is difficult to effectively coordinate in traditional train traction power supply systems that include the power grid, renewable energy devices, energy storage devices, and trains (referred to as "grid-source-storage-train"), leading to insufficient utilization of renewable energy and a low renewable energy consumption rate. Summary of the Invention

[0005] The purpose of this application is to provide an energy management method and device for a train traction power supply system, as well as a readable storage medium, to solve the problem of low renewable energy consumption rate.

[0006] To solve the above-mentioned technical problems, this specification is implemented as follows: Firstly, an energy management method for a train traction power supply system is provided, including: The system obtains the traction load power of the train belonging to the train traction power supply system at the target time, the energy supply parameters of the multi-source energy supply equipment, and the energy storage parameters of the energy storage equipment. The energy supply parameters include the output power of the renewable energy equipment in the multi-source energy supply equipment at the target time, and the energy storage parameters include the capacity of the electrolyzer and the ammonia synthesis unit in the energy storage equipment. Based on the traction load power, energy supply parameters, energy storage parameters, and power balance constraints of the train traction power supply system, the operating power of the electrolyzer and ammonia synthesis unit at the target time is predicted with the objective function of maximizing the overall energy benefit of the train traction power supply system as the optimization objective. The objective function is constructed based on the mathematical models of the energy supply equipment and energy storage equipment at the corresponding time, as well as their benefits and costs. Energy management of the train traction power supply system is performed based on the operating power of the electrolyzer and ammonia synthesis unit at the target time.

[0007] Optionally, the renewable energy equipment includes a wind power system, a photovoltaic system, and the train, and the acquisition of power supply parameters for the multi-source energy supply equipment includes: The wind power output of a single wind turbine in the wind power system, the photovoltaic output of a single photovoltaic device in the corresponding photovoltaic system, and the braking energy of the train are collected at the target time. The total wind power output of the wind power system is obtained based on the wind power output collected by a single wind turbine at the target time, and the total photovoltaic power output of the photovoltaic system is obtained based on the photovoltaic power collected by a single photovoltaic device at the target time; The total wind power output is defined as the output power of the wind power system at the target time; The total photovoltaic output is defined as the output power of the photovoltaic system at the target time. The braking energy is determined as the output power of the train at the target time.

[0008] Optionally, the mathematical model of the electrolytic cell at the corresponding time is shown in the following equation:

[0009] in, Let t be the operating power of the electrolytic cell. The energy conversion efficiency for hydrogen production in the electrolyzer is given.

[0010] Optionally, the mathematical model of the ammonia synthesis device at the corresponding time is shown in the following equation:

[0011] in, Let t be the operating power of the ammonia synthesis device. Let t be the amount of hydrogen required for the ammonia synthesis apparatus to synthesize ammonia. The efficiency of nitrogen separation in the ammonia synthesis unit. The efficiency of ammonia synthesis in the ammonia synthesis device.

[0012] Optionally, the energy storage device further includes a hydrogen storage tank, disposed between the electrolyzer and the ammonia synthesis unit; The amount of hydrogen stored in the hydrogen storage tank at the target time is related to the amount of hydrogen stored at the previous time, the amount of hydrogen converted at the target time, and the amount of hydrogen required for ammonia synthesis.

[0013] Optionally, the mathematical model of the ammonia synthesis device at a corresponding time also includes response constraints, which are used to constrain the hydrogen storage tank to output the same amount of hydrogen required for ammonia synthesis to the ammonia synthesis device within a preset adjustment cycle including multiple time points.

[0014] Optionally, the train traction power supply system further includes a battery, which serves as one of the multi-source power supply devices when supplying energy and as one of the energy storage devices when storing energy. When supplying energy, the power supply parameters include the output power of the renewable energy device in the multi-source power supply device at the target time and the stored charge of the battery in the multi-source power supply device at the previous time at the target time. When storing energy, the energy storage parameters include the capacity of the electrolyzer and ammonia synthesis unit in the energy storage device and the discharge power of the battery in the energy storage device at the target time. Predicting the operating power of the electrolyzer and ammonia synthesis unit at the target time includes: predicting the operating power of the electrolyzer and ammonia synthesis unit at the target time, and the charging power or discharging power of the battery at the target time; Based on the operating power of the electrolyzer and ammonia synthesis unit at the target time, energy management of the train traction power supply system is performed, including: based on the operating power of the electrolyzer and ammonia synthesis unit at the target time and the charging or discharging power of the battery at the target time, the energy management of the train traction power supply system is performed.

[0015] Optionally, the power balance constraint condition is that the power supply and power consumption of the train traction power supply system are balanced at the corresponding time. The power supply includes the sum of the power purchased by the power grid in the multi-source power supply equipment, the output power of the renewable energy equipment, and the discharge power of the battery. The power consumption includes the traction load power, the working power of the electrolytic cell, the working power of the ammonia synthesis unit, the charging power of the battery, and the power sold by the power grid.

[0016] In a second aspect, an energy management device for a train traction power supply system is provided, comprising a processor and a memory, the memory storing programs or instructions executable on the processor, the programs or instructions, when executed by the processor, implementing the steps of the method described in the first aspect.

[0017] Thirdly, a readable storage medium is provided that stores a program or instructions which, when executed by a processor, implement the steps of the method described in the first aspect.

[0018] In this embodiment, the traction load power of the train belonging to the train traction power supply system at a target time, the energy supply parameters of the multi-source energy supply equipment, and the energy storage parameters of the energy storage equipment are obtained. The energy supply parameters include the output power of the renewable energy equipment in the multi-source energy supply equipment at the target time, and the energy storage parameters include the capacity of the electrolyzer and ammonia synthesis unit in the energy storage equipment. Based on the traction load power, energy supply parameters, energy storage parameters, and the power balance constraints of the train traction power supply system, the operating power of the electrolyzer and ammonia synthesis unit at the target time is predicted with the objective function corresponding to maximizing the overall energy benefit of the train traction power supply system as the optimization objective. The objective function is constructed based on the mathematical models and benefits and costs of the energy supply equipment and energy storage equipment at the corresponding time. Based on the operating power of the electrolyzer and ammonia synthesis unit at the target time, the energy management of the train traction power supply system is performed. Therefore, energy storage devices including electrolyzers and ammonia synthesis units can be introduced to convert excess electrical energy from renewable energy into hydrogen and ammonia energy on-site. Ammonia, as an energy carrier that can be stored for a long time and an efficient medium for hydrogen energy transportation, can fundamentally make up for the shortcomings of traditional battery electrochemical energy storage in terms of energy storage scale and duration. It can effectively coordinate the energy in the train traction power supply system, so that renewable energy can be fully utilized, realize the transfer of energy in time and space, fundamentally solve the problem of source-load time and space mismatch caused by the time and space fluctuation of renewable energy and the fluctuation of train traction load, and improve the utilization rate of renewable energy. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart illustrating the energy management method of a train traction power supply system according to an embodiment of this application.

[0020] Figure 2 This is a schematic flowchart illustrating a specific example of an energy management method for a train traction power supply system according to an embodiment of this application.

[0021] Figure 3 This is a structural block diagram of the energy management device of the train traction power supply system according to an embodiment of this application. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. The drawing numbers in this application are only used to distinguish the various steps in the solution and are not used to limit the execution order of the various steps. The specific execution order is subject to the description in the specification.

[0023] To address the problems existing in the prior art, embodiments of this application provide an energy management method for a train traction power supply system, such as... Figure 1 As shown, the process includes steps 102 to 106.

[0024] Step 102: Obtain the traction load power of the train belonging to the train traction power supply system at the target time, the energy supply parameters of the multi-source energy supply equipment, and the energy storage parameters of the energy storage equipment. The energy supply parameters include the output power of the renewable energy equipment in the multi-source energy supply equipment at the target time, and the energy storage parameters include the capacity of the electrolyzer and the ammonia synthesis device in the energy storage equipment.

[0025] In this embodiment, the train traction power supply system of this application includes multi-source energy supply equipment and energy storage equipment. As the name suggests, multi-source energy supply equipment refers to energy supply equipment from various sources, including the power grid and renewable energy equipment, used to provide energy or electrical energy to the trains belonging to the train traction power supply system. The energy storage equipment includes an electrolyzer and an ammonia synthesis unit. The electrolyzer is used to convert the output power of the renewable energy equipment into hydrogen, and the ammonia synthesis unit is used to synthesize ammonia from the hydrogen converted by the electrolyzer.

[0026] In this embodiment, an energy storage device including an electrolyzer and an ammonia synthesis unit is introduced to utilize renewable energy to convert excess electrical energy into hydrogen and ammonia energy on-site. Ammonia, as a long-term storable energy carrier and an efficient hydrogen transport medium, can fundamentally compensate for the shortcomings of traditional battery electrochemical energy storage in terms of energy scale and duration. This not only improves the utilization rate of renewable energy but also realizes the spatial and temporal transfer of energy, fundamentally solving the problem of source-load spatial and temporal mismatch. This embodiment provides a multi-source energy supply device including a power grid and renewable energy equipment, and a train traction power supply system including an energy storage device with an electrolyzer and an ammonia synthesis unit. It aims to provide an energy management scheme for the system through the energy management method of the train traction power supply system, providing a basis for the system's operation and scheduling.

[0027] To address this, this embodiment requires real-time acquisition of the train's traction load power, the energy supply parameters of the multi-source energy supply equipment, and the energy storage parameters of the energy storage equipment at different times. The train's traction load power refers to the traction load energy required for the train's operation at a given time. This traction load power may vary at different times and can be measured at substations located along the train's route. The output power of the renewable energy equipment at different times can be obtained through actual measurement. The capacity of the electrolyzer and ammonia synthesis unit in the energy storage equipment refers to the production capacity of the corresponding equipment and is a known constant.

[0028] In one specific embodiment, the renewable energy equipment includes a wind power system, a photovoltaic system, and the train. Acquiring the power supply parameters of the multi-source energy supply equipment includes: collecting the wind power output of a single wind turbine in the wind power system at a target time, the photovoltaic output of a single photovoltaic device in the photovoltaic system at the target time, and the braking energy of the train; obtaining the total wind power output of the wind power system based on the wind power output collected from a single wind turbine at the target time, and obtaining the total photovoltaic output of the photovoltaic system based on the photovoltaic output collected from a single photovoltaic device at the target time; determining the total wind power output as the output power of the wind power system at the target time; determining the total photovoltaic output as the output power of the photovoltaic system at the target time; and determining the braking energy as the output power of the train at the target time.

[0029] In this embodiment, the renewable energy equipment includes a wind power system, a photovoltaic system, and the train itself. The wind power system generates renewable energy from wind power when there is wind in the environment, and the photovoltaic system generates renewable energy from photovoltaic power when there is sunlight during the day. The use of photovoltaic and wind power achieves energy conservation and emission reduction in the train traction power supply system.

[0030] As a renewable energy source, the train utilizes the regenerated braking energy as its own. During braking, a significant amount of braking energy is generated but often wasted. Effectively utilizing this braking energy as renewable energy can further improve the energy-saving and emission-reduction efficiency of the train's traction power supply system.

[0031] In this embodiment, the train traction power supply system involving energy management and scheduling refers to the system that, when a train passes through a location area along a railway line or substation where wind power systems and / or photovoltaic systems are deployed, collects the output power of the wind power systems and / or photovoltaic systems in that area at a target time, as well as the traction load power of the train in that area at the target time, for energy management of the train traction power supply system at that target time. If the train travels to the next location area where wind power systems and / or photovoltaic systems are deployed, then the energy management of the train traction power supply system is performed by combining the output power of the wind power systems and / or photovoltaic systems in the next area collected at the corresponding time.

[0032] The calculation formulas for real-time data collection of wind power output and photovoltaic output from wind power systems and photovoltaic systems at different times are as follows:

[0033] in, Let t be the total wind power output of the wind power system. For wind power installed capacity, For wind power output normalized to time t, For the total photovoltaic output of the photovoltaic system, For photovoltaic installed capacity, To contribute to the normalization of photovoltaic power.

[0034] For a wind power system, the wind power output of a single wind turbine within the system at time t can be collected. For example, if the rated wind power output of a wind turbine is 10 watts, and the measured wind power output of a certain wind turbine at time t is 8 watts, then the normalized wind power output at time t is 8 / 10 = 80%. Multiplying the normalized wind power output at time t by the installed wind power capacity (i.e., the maximum total power of the multiple wind turbine units included in the wind power system), for example, 100 watts, the total wind power output of the wind power system at time t can be calculated to be 80 watts.

[0035] Similarly, for a photovoltaic (PV) system, the PV output of a single PV device within the system at time t can be collected. For example, if the rated PV output of a PV device is 9 watts, and the measured PV output of a certain PV device at time t is 9 watts, then the normalized PV output at time t is 9 / 10 = 90%. Multiplying the normalized PV output at time t by the PV installed capacity (i.e., the maximum total power of the multiple PV devices in the PV system), for example, 200 watts, the total PV output of the PV system at time t can be calculated to be 180 watts.

[0036] Therefore, the output power of the wind power system, the output power of the photovoltaic system, and the output power of the train at each time can be measured.

[0037] Step 104: Based on the traction load power, energy supply parameters, energy storage parameters, and the power balance constraints of the train traction power supply system, with the objective of maximizing the overall energy benefit of the train traction power supply system as the optimization objective, predict the operating power of the electrolyzer and ammonia synthesis unit at the target time. The objective function is constructed based on the mathematical models of the energy supply equipment and the energy storage equipment at the corresponding time, as well as the benefits and costs.

[0038] In this step, the power balance among the train, multi-source energy supply equipment and energy storage equipment involved in the train traction power supply system is the balance between the power supply and power consumption of the train traction power supply system at the corresponding time. The power supply includes the sum of the output power of the multi-source energy supply equipment, and the power consumption includes the traction load power of the train, the working power of the electrolyzer and the working power of the ammonia synthesis unit at the corresponding time.

[0039] That is, when there is still a surplus of renewable energy in the renewable energy equipment based on the traction load power of the train at the target time, the electrolyzer and ammonia synthesis unit of the energy storage equipment can use the appropriate working power to electrolyze the surplus renewable energy to obtain hydrogen, and then synthesize ammonia from the hydrogen for storage.

[0040] Under the constraint of power balance, by combining the objective function of the overall energy benefit of the train traction power supply system based on the mathematical models of the energy supply equipment and energy storage equipment at corresponding times and the benefits and costs, and with the maximization of the objective function as the optimization objective, the operating power of the electrolyzer and ammonia synthesis unit at corresponding times can be predicted.

[0041] In other words, if the renewable energy generated by the renewable energy equipment in the area through which the train passes at the target time is sufficient for the train's traction load power and there is a surplus, the operating power of the electrolyzer and ammonia synthesis unit that convert the surplus renewable energy into hydrogen and ammonia at the target time can be predicted at the corresponding time, so as to maximize the overall energy benefit of the train's traction power supply system.

[0042] The overall energy benefit of the train traction power supply system is related to the benefits and costs of the included energy supply and storage equipment at the corresponding time. The optimization goal is to ensure that the operating power of the electrolyzer and ammonia synthesis unit at the target time not only maintains power balance, but also maximizes the overall energy benefit of the train traction power supply system.

[0043] The revenue at the corresponding time point includes revenue from ammonia sales, while the costs at the corresponding time point include the installation and maintenance costs of renewable energy equipment, the installation and maintenance costs of electrolyzers, and the installation and maintenance costs of ammonia synthesis units.

[0044] Of course, if the renewable energy generated by the renewable energy equipment in the area through which the train passes at the target time is insufficient for the train's traction load power, the output power of the power grid in the multi-source energy supply equipment can be used to power the train, thereby achieving power balance between the multi-source energy supply equipment and the energy storage equipment.

[0045] The mathematical models of the electrolyzer and ammonia synthesis unit involved in the energy storage equipment at corresponding times are described below.

[0046] The mathematical model of the electrolytic cell at the corresponding time is shown in the following equation:

[0047] in, Let t be the operating power of the electrolytic cell. The energy conversion efficiency for hydrogen production in the electrolyzer is given.

[0048] The electrolyzer can be an alkaline water electrolyzer, which works by passing electricity through an alkaline electrolyte, such as potassium hydroxide (KOH) solution, to decompose water into hydrogen and oxygen. In other words, excess electrical energy from renewable energy sources is converted into hydrogen energy. This conversion is mainly achieved through water electrolysis technology, using excess electrical energy from renewable energy sources to decompose water into hydrogen and oxygen. The decomposed hydrogen is then used in an ammonia synthesis unit for ammonia synthesis.

[0049] Electrolytic cells are typically modular devices, meaning the capacity of each cell is predetermined at the factory. In practical applications, multiple electrolytic cells are usually connected in series, as shown in the following formula:

[0050]

[0051]

[0052] in, Let t be the output power of the electrolytic cell. The energy conversion efficiency of hydrogen production in an electrolyzer. Let be the amount of hydrogen gas converted at time t. The capacity of the electrolytic cell in the project. The capacity of a single electrolytic cell. For the number of electrolytic cells, This is the minimum operating power coefficient of the electrolytic cell. This is the maximum operating power coefficient of the electrolytic cell.

[0053] Specifically, the mathematical model of the ammonia synthesis device at the corresponding time is shown in the following equation:

[0054] in, Let t be the operating power of the ammonia synthesis device. Let t be the amount of hydrogen required for the ammonia synthesis apparatus to synthesize ammonia. The efficiency of nitrogen separation in the ammonia synthesis unit. The efficiency of ammonia synthesis in the ammonia synthesis device.

[0055] In practical engineering, the commonly used method for hydrogen to ammonia synthesis is to separate nitrogen from the air using an air separation device employing pressure swing adsorption (PSA) technology, and then synthesize ammonia by combining the hydrogen converted from the electrolytic cell and the nitrogen separated by the air separation device in an ammonia synthesis unit using the Hubble process.

[0056] In this process, the embodiments of this application transform the two chemical processes of nitrogen separation and ammonia synthesis into simple hydrogen and nitrogen consumption ammonia synthesis power-related functions, as described below.

[0057] (1) (2) in, Let t be the operating power of the air separator. Let t be the operating power of the ammonia synthesis unit. The nitrogen separation efficiency of the air separation device. The ammonia synthesis efficiency of the ammonia synthesis unit. Let be the nitrogen yield at time t. Let be the ammonia production at time t.

[0058] In the chemical process of ammonia production, the ratio of hydrogen and nitrogen consumption to ammonia synthesis is shown in the following formula: (3) Therefore, combining equations (1)-(3), the mathematical model of the entire hydrogen-to-ammonia synthesis process can be simplified to equation (4), which means that the air separation device and the ammonia synthesis device involved in the two processes of nitrogen separation and ammonia synthesis are collectively referred to as the ammonia synthesis device.

[0059] (4) in, The operating power of the ammonia synthesis unit at time t. This refers to the nitrogen separation efficiency of the air separation unit in the ammonia synthesis plant. The ammonia synthesis efficiency of the ammonia synthesis unit in the ammonia synthesis plant.

[0060] Due to the randomness of renewable energy power supply and train traction load, the operating power of electrolyzers and ammonia synthesis units used for hydrogen and ammonia production needs to be dynamically scheduled. Based on the traction load power and the output power of the renewable energy equipment collected at corresponding times, the operating power of the electrolyzers can be dynamically adjusted in a timely manner, or hydrogen conversion can be stopped. However, the scheduling cycle of the ammonia synthesis unit is relatively long, and it cannot be stopped at any time after startup. Therefore, the rate at which the electrolyzer produces hydrogen through water electrolysis differs from the rate at which the ammonia synthesis unit consumes hydrogen to synthesize ammonia from hydrogen and nitrogen.

[0061] In one embodiment, a hydrogen storage tank can be configured as a buffer for hydrogen energy consumption. Optionally, the energy storage device further includes a hydrogen storage tank disposed between the electrolyzer and the ammonia synthesis unit; wherein the amount of hydrogen stored in the hydrogen storage tank at a target time is related to the amount of hydrogen stored at the previous time, the amount of hydrogen converted at the target time, and the amount of hydrogen required for ammonia synthesis.

[0062] The mathematical model of the hydrogen storage tank is shown in the following equation:

[0063]

[0064] in, Let t be the amount of hydrogen stored in the hydrogen storage tank. This represents the minimum capacity of the hydrogen storage tank. This represents the maximum capacity of the hydrogen storage tank. The amount of hydrogen flowing into the hydrogen storage tank at time t (i.e., the amount of hydrogen converted by the electrolyzer at time t). Let t be the amount of hydrogen flowing out of the hydrogen storage tank at time t (i.e., the amount of hydrogen required for the ammonia synthesis unit to synthesize ammonia).

[0065] In addition, since the chemical process of ammonia production is relatively complex, the start-up / stop time and response speed of the ammonia synthesis unit need to be considered during actual operation to ensure the efficiency and safety of ammonia synthesis.

[0066] Optionally, the mathematical model of the ammonia synthesis device at a corresponding time also includes response constraints, which are used to constrain the hydrogen storage tank to output the same amount of hydrogen required for ammonia synthesis to the ammonia synthesis device within a preset adjustment cycle including multiple time points.

[0067] As mentioned above, the operating power of the electrolyzer and ammonia synthesis unit at each corresponding time point is predicted by maximizing the objective function corresponding to the power balance constraint and the overall energy benefit of the train traction power supply system. Correspondingly, based on the predicted operating power of the electrolyzer at each corresponding time point and the mathematical model of the electrolyzer, the amount of hydrogen flowing from the electrolyzer into the hydrogen storage tank at that corresponding time point can be calculated. Based on the predicted operating power of the ammonia synthesis unit at the corresponding time and the mathematical model of the ammonia synthesis unit, the amount of hydrogen flowing out of the hydrogen storage tank and supplied to the ammonia synthesis unit at the corresponding time can be calculated. .

[0068] To ensure the efficiency and safety of ammonia synthesis, the ammonia synthesis unit does not constantly adjust the amount of hydrogen required for ammonia synthesis; instead, adjustments are made based on a regulation cycle. That is, during multiple moments within this regulation cycle, the ammonia synthesis unit will not respond to changes in hydrogen supply. Adjustments are made in real time. After an initial adjustment of the hydrogen quantity at the beginning of each adjustment cycle, the quantity remains constant until the beginning of the next adjustment cycle, at which point adjustments are made again based on the calculated hydrogen quantity, maintaining this consistency throughout the entire adjustment cycle. Correspondingly, this ensures that the hydrogen storage tank supplies the same amount of hydrogen required for ammonia synthesis to the ammonia synthesis unit throughout the adjustment cycle of the ammonia synthesis unit.

[0069] The dynamic process of the response to the constraint can be expressed by the following equation:

[0070]

[0071]

[0072] in, To ensure that the hydrogen storage tank supplies the amount of hydrogen required for ammonia synthesis to the ammonia synthesis unit during the unit's regulation cycle. The total optimization time corresponding to the objective function of the train traction power supply system, for example, one day, is the prediction of the operating power of the electrolyzer and ammonia synthesis unit at each time point within multiple time periods of the day, based on the optimization objective of maximizing the objective function, and the intervals between each time point. This represents the interval between time t+1 and time t, for example, 1 minute. The adjustment cycle for the ammonia synthesis unit, for example, 10 minutes, includes 10 intervals. ; This is the rated hydrogen consumption of the ammonia synthesis unit. , These are the minimum power factor and maximum power factor of the ammonia synthesis unit, respectively. , The power decrease and increase coefficients for the ammonia synthesis unit; k represents the number of moments included in the total optimization time K, for example, 3600 one-minute intervals within a day. Then k takes values ​​between 1 and 3600; The table shows the amount of hydrogen required for ammonia synthesis in the ammonia synthesis unit at the (k+1)th corresponding time, where trans represents a constant.

[0073] Therefore, by using the above response constraints, it can be ensured that the ammonia synthesis unit responds to the predicted change in the amount of hydrogen required for ammonia synthesis once within the corresponding adjustment cycle.

[0074] Step 106: Based on the operating power of the electrolyzer and ammonia synthesis unit at the target time, perform energy management of the train traction power supply system.

[0075] After predicting the corresponding operating power through step 104, the power is supplied to the corresponding electrolytic cell and ammonia synthesis unit for automatic adjustment, thereby realizing the energy management and scheduling of the train traction power supply system.

[0076] In one embodiment, the train traction power supply system further includes a battery, which serves as one of the multi-source power supply devices when supplying energy and as one of the energy storage devices when storing energy. When supplying energy, the power supply parameters include the output power of the renewable energy devices in the multi-source power supply devices at the target time and the stored energy of the battery in the multi-source power supply devices at the previous time at the target time. When storing energy, the energy storage parameters include the capacity of the electrolyzer and ammonia synthesis unit in the energy storage device and the discharge power of the battery in the energy storage device at the target time. Predicting the operating power of the electrolyzer and ammonia synthesis unit at the target time includes: predicting the operating power of the electrolyzer and ammonia synthesis unit at the target time, and the charging power or discharging power of the battery at the target time. Based on the operating power of the electrolyzer and ammonia synthesis unit at the target time, performing energy management of the train traction power supply system includes: performing energy management of the train traction power supply system based on the operating power of the electrolyzer and ammonia synthesis unit at the target time, and the charging power or discharging power of the battery at the target time.

[0077] In this embodiment, when the regenerative energy from the regenerative energy device is insufficient for the train's traction load power at the target time, the battery can act as a multi-source power supply device to discharge and power the train. In the ward area, when the regenerative energy from the regenerative energy device is sufficient for the train's traction load power and there is a surplus, the battery can act as an energy storage device to charge and store the regenerative energy. After the battery is fully charged, if there is still surplus regenerative energy, it can be converted into hydrogen and ammonia energy by combining it with the electrolyzer and ammonia synthesis device in the energy storage device.

[0078] The mathematical model for energy storage in a battery is shown in the following equation: (5) (6) (7) in, Let t be the amount of energy stored in the battery. For the charging efficiency of the storage battery, The charging power of the battery. This refers to the battery's discharge efficiency. This refers to the battery's discharge power. Let be the interval between time t and time t-1. The rated charging power of the battery. This refers to the rated discharge power of the battery. This is the maximum storage capacity of the battery. This represents the minimum storage capacity of the battery.

[0079] Equations (5)-(7) are mathematical models of battery operation, where equation (5) is the charging and discharging process of the battery, equation (6) is the charging power constraint of the battery, and equation (7) is the discharging power constraint of the battery.

[0080] In addition, the following formula indicates that a battery can only be in one of two states at a time: charging or discharging.

[0081]

[0082] in, This is a binary variable representing the charge / discharge flags of the battery; 1 indicates charging, and 0 indicates discharging.

[0083] Correspondingly, in step 102, when the battery is supplying energy, the obtained energy supply parameters include the output power of the renewable energy equipment in the multi-source energy supply equipment at the target time and the stored energy of the battery at the previous time at the target time; when storing energy, the obtained energy storage parameters include the capacity of the electrolyzer and the ammonia synthesis device in the energy storage equipment and the discharge power of the battery at the target time.

[0084] Correspondingly, in step 104, based on the traction load power, energy supply parameters, energy storage parameters and the power balance constraints of the train traction power supply system, the objective of maximizing the overall energy benefit of the train traction power supply system is used as the optimization objective to predict the operating power of the electrolyzer and ammonia synthesis unit at the target time, and the charging power or discharging power of the battery at the target time.

[0085] Specifically, the power balance constraint condition is that the power supply and power consumption of the train traction power supply system are balanced at the corresponding time. The power supply includes the sum of the power purchased by the power grid in the multi-source power supply equipment, the output power of the renewable energy equipment and the discharge power of the battery. The power consumption includes the traction load power, the working power of the electrolytic cell, the working power of the ammonia synthesis unit, the charging power of the battery and the power sold by the power grid.

[0086] Taking a train traction power supply system, which includes the power grid, wind power system, photovoltaic system, train, battery, electrolyzer, and ammonia synthesis unit, as an example, in order to ensure the safe and reliable operation of the train traction power supply system, the power balance constraint shown in the following formula needs to be met:

[0087] in, For the total wind power output of the wind power system, For the total photovoltaic output of the photovoltaic system, The amount of electricity purchased from the power grid, This refers to the battery's discharge power. This refers to the traction load power of the train. This refers to the operating power of the electrolytic cell. This refers to the operating power of the ammonia synthesis unit. The charging power of the battery. This refers to the power output sold to the power grid.

[0088] Correspondingly, in the process of energy management of the train traction power supply system, in order to achieve a reasonable energy scheduling scheme, the constructed energy scheduling objective function is to maximize the overall energy benefit of the train traction power supply system.

[0089] The formula for the total energy gain J corresponding to the objective function is as follows:

[0090] in, To generate revenue from selling electricity to the grid, excess electrical energy stored in batteries can be sold to the grid. To generate revenue from ammonia sales, the ammonia synthesized by the ammonia synthesis unit can be sold. To reduce the cost of purchasing electricity from the grid, when the power supply from renewable energy sources and batteries is insufficient for the traction load of the train, electricity can be purchased from the grid. For scheduling time intervals, The installation and maintenance costs of renewable energy equipment, The installation and maintenance costs of the electrolyzer and hydrogen storage tank, For the installation and operation and maintenance costs of the ammonia synthesis unit, This refers to the installation and maintenance costs of the storage battery.

[0091] The annualized cost of equipment investment (CRF) is shown in the following formula:

[0092] Where r is a preset value, for example, 8%.

[0093] Correspondingly, the installation and operation costs of renewable energy equipment, including wind power systems and photovoltaic systems, are shown in the following formula:

[0094] in, For the lifespan of wind power systems. The unit installed cost of wind power systems For wind power installed capacity, As a cost factor for the operation and maintenance of wind power systems, For the lifespan of photovoltaic systems, The unit installation cost of a photovoltaic system. For the installed capacity of photovoltaic systems, This is the operation and maintenance cost factor for photovoltaic systems.

[0095] The installation and maintenance costs of the AE electrolyzer and hydrogen storage tank are shown in the following formula:

[0096] in, This refers to the lifespan of the electrolytic cell. The unit installation cost of the electrolytic cell, For the installed capacity of the electrolytic cell, As a cost factor for the operation and maintenance of electrolytic cells, This refers to the lifespan of hydrogen storage tanks. The unit installation cost of hydrogen storage tanks, For the hydrogen storage tank capacity, This is a cost factor for the operation and maintenance of hydrogen storage tanks.

[0097] The installation and maintenance costs of an ammonia synthesis unit are shown in the following formula:

[0098] in, The lifespan of the ammonia synthesis unit. The unit installed cost of an ammonia synthesis unit. For the installed capacity of the ammonia synthesis unit, This is a cost factor for the operation and maintenance of the ammonia synthesis unit.

[0099] The installation and maintenance costs of the battery are shown in the following formula: (1.25) in, This refers to the lifespan of the battery. The unit installation cost of the battery. For battery installed capacity, This is a cost factor for battery operation and maintenance.

[0100] By combining the objective function and the mathematical models and power constraints of each device in the train traction power supply system, an optimization problem can be constructed and solved to obtain the working power of the electrolyzer and ammonia synthesis unit, as well as the charging or discharging power of the battery at the corresponding time, thereby realizing the energy management and scheduling of the train traction power supply system.

[0101] The following is combined Figure 2 This application describes specific examples of the energy management method for a train traction power supply system. For example... Figure 2 As shown, it includes the following steps: Step 202: Obtain the output power of the wind power system and the photovoltaic power system in the train traction power supply system at the target time. Step 204: Obtain the stored energy and discharge power of the batteries in the train traction power supply system at the target time in the previous time, as well as the capacity of the hydrogen storage tank, electrolyzer and ammonia synthesis unit. Step 206: Obtain the traction load power of the train in the train traction power supply system at the target time; Step 208: Based on the parameters obtained in steps 202, 204 and 206, energy management scheduling is performed in combination with the objective function, the mathematical model of each device and the power constraint conditions. Step 210: Output the predicted power of the battery, electrolyzer, and ammonia synthesis unit.

[0102] In this embodiment, the traction load power of the train belonging to the train traction power supply system at a target time, the energy supply parameters of the multi-source energy supply equipment, and the energy storage parameters of the energy storage equipment are obtained. The energy supply parameters include the output power of the renewable energy equipment in the multi-source energy supply equipment at the target time, and the energy storage parameters include the capacity of the electrolyzer and ammonia synthesis unit in the energy storage equipment. Based on the traction load power, energy supply parameters, energy storage parameters, and the power balance constraints of the train traction power supply system, the operating power of the electrolyzer and ammonia synthesis unit at the target time is predicted with the objective function corresponding to maximizing the overall energy benefit of the train traction power supply system as the optimization objective. The objective function is constructed based on the mathematical models and benefits and costs of the energy supply equipment and energy storage equipment at the corresponding time. Based on the operating power of the electrolyzer and ammonia synthesis unit at the target time, the energy management of the train traction power supply system is performed. Therefore, energy storage devices including electrolyzers and ammonia synthesis units can be introduced to convert excess electrical energy from renewable energy into hydrogen and ammonia energy on-site. Ammonia, as an energy carrier that can be stored for a long time and an efficient medium for hydrogen energy transportation, can fundamentally make up for the shortcomings of traditional battery electrochemical energy storage in terms of energy storage scale and duration. It can effectively coordinate the energy in the train traction power supply system, so that renewable energy can be fully utilized, realize the transfer of energy in time and space, fundamentally solve the problem of source-load time and space mismatch caused by the time and space fluctuation of renewable energy and the fluctuation of train traction load, and improve the utilization rate of renewable energy.

[0103] Optionally, such as Figure 3 As shown, this application embodiment also provides an energy management device 2000 for a train traction power supply system, including a processor 2400 and a memory 2200. The memory 2200 stores a program or instructions that can run on the processor 2400. When the program or instructions are executed by the processor 2400, they implement the various steps of the above-described energy management method embodiment for the train traction power supply system and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0104] This application also provides a readable storage medium storing a program or instructions. When executed by a processor, the program or instructions implement the various processes of any of the above-described energy management method embodiments for a train traction power supply system, achieving the same technical effects. To avoid repetition, these will not be described again here. The readable storage medium includes computer-readable storage media, such as read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0105] This application also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program. The computer program is operable to enable a computer to execute various processes of any of the above-described energy management method embodiments for a train traction power supply system, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0106] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0107] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0108] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. An energy management method for a train traction power supply system, characterized in that, include: The system obtains the traction load power of the train belonging to the train traction power supply system at the target time, the energy supply parameters of the multi-source energy supply equipment, and the energy storage parameters of the energy storage equipment. The energy supply parameters include the output power of the renewable energy equipment in the multi-source energy supply equipment at the target time, and the energy storage parameters include the capacity of the electrolyzer and the ammonia synthesis unit in the energy storage equipment. Based on the traction load power, energy supply parameters, energy storage parameters, and power balance constraints of the train traction power supply system, the operating power of the electrolyzer and ammonia synthesis unit at the target time is predicted with the objective function of maximizing the overall energy benefit of the train traction power supply system as the optimization objective. The objective function is constructed based on the mathematical models of the energy supply equipment and energy storage equipment at the corresponding time, as well as their benefits and costs. Based on the operating power of the electrolyzer and ammonia synthesis unit at the target time, energy management of the train traction power supply system is performed.

2. The method according to claim 1, characterized in that, The renewable energy equipment includes a wind power system, a photovoltaic system, and the train. The energy supply parameters of the multi-source energy supply equipment are acquired, including: The wind power output of a single wind turbine in the wind power system, the photovoltaic output of a single photovoltaic device in the corresponding photovoltaic system, and the braking energy of the train are collected at the target time. The total wind power output of the wind power system is obtained based on the wind power output collected by a single wind turbine at the target time, and the total photovoltaic power output of the photovoltaic system is obtained based on the photovoltaic power collected by a single photovoltaic device at the target time; The total wind power output is defined as the output power of the wind power system at the target time; The total photovoltaic output is defined as the output power of the photovoltaic system at the target time. The braking energy is determined as the output power of the train at the target time.

3. The method according to claim 1, characterized in that, The mathematical model of the electrolytic cell at the corresponding time is shown in the following equation: in, Let t be the operating power of the electrolytic cell. The energy conversion efficiency for hydrogen production in the electrolyzer is given.

4. The method according to claim 3, characterized in that, The mathematical model of the ammonia synthesis device at the corresponding time is shown in the following equation: in, Let t be the operating power of the ammonia synthesis device. Let t be the amount of hydrogen required for the ammonia synthesis apparatus to synthesize ammonia. The efficiency of nitrogen separation in the ammonia synthesis unit. The efficiency of ammonia synthesis in the ammonia synthesis device.

5. The method according to claim 4, characterized in that, The energy storage device also includes a hydrogen storage tank, which is disposed between the electrolyzer and the ammonia synthesis unit; The amount of hydrogen stored in the hydrogen storage tank at the target time is related to the amount of hydrogen stored at the previous time, the amount of hydrogen converted at the target time, and the amount of hydrogen required for ammonia synthesis.

6. The method according to claim 5, characterized in that, The mathematical model of the ammonia synthesis unit at the corresponding time also includes response constraints. The response constraints are used to ensure that the hydrogen storage tank outputs the same amount of hydrogen required for ammonia synthesis to the ammonia synthesis unit within a preset adjustment cycle including multiple time points in the ammonia synthesis unit.

7. The method according to any one of claims 1 to 6, characterized in that, The train traction power supply system also includes a storage battery, which serves as one of the multi-source power supply devices when supplying energy and as one of the energy storage devices when storing energy. When supplying energy, the power supply parameters include the output power of the renewable energy device in the multi-source power supply device at the target time and the stored charge of the storage battery in the multi-source power supply device at the previous time at the target time. When storing energy, the energy storage parameters include the capacity of the electrolyzer and ammonia synthesis unit in the energy storage device and the discharge power of the storage battery in the energy storage device at the target time. Predicting the operating power of the electrolyzer and ammonia synthesis unit at the target time includes: predicting the operating power of the electrolyzer and ammonia synthesis unit at the target time, and the charging power or discharging power of the battery at the target time; Based on the operating power of the electrolyzer and ammonia synthesis unit at the target time, energy management of the train traction power supply system is performed, including: based on the operating power of the electrolyzer and ammonia synthesis unit at the target time and the charging or discharging power of the battery at the target time, the energy management of the train traction power supply system is performed.

8. The method according to claim 7, characterized in that, The power balance constraint condition is that the power supply and power consumption of the train traction power supply system are balanced at the corresponding time. The power supply includes the sum of the power purchased by the power grid in the multi-source power supply equipment, the output power of the renewable energy equipment and the discharge power of the battery. The power consumption includes the traction load power, the working power of the electrolytic cell, the working power of the ammonia synthesis unit, the charging power of the battery and the power sold by the power grid.

9. An energy management device for a train traction power supply system, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the method as described in any one of claims 1-8.

10. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the method as described in any one of claims 1-8.

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