Traction power supply simulation system and simulation method for urban rail vehicles

Abstract

The present invention discloses a traction power supply simulation system and a simulation method for urban rail vehicles, and the present invention relates to the technical field of urban rail transit. It includes: an operating parameter acquisition module for acquiring the characteristic parameters of urban rail vehicles and the state parameters during operation; an instantaneous resistance power calculation module for calculating and characterizing the wind resistance coefficient and the rolling resistance coefficient, and correcting the rolling resistance coefficient through the environmental humidity, so as to calculate the rolling resistance and the air resistance; a comprehensive energy consumption analysis module for calculating the instantaneous power of the vehicle and the operating energy consumption of the rail vehicle; a substation loss characterization module for calculating the line loss and the load loss of the substation according to the comprehensive energy consumption of the rail vehicle; and a transmission network consumption summary module for obtaining the consumption of the transmission network. It can effectively calculate the rolling resistance and the air resistance of the vehicle, so as to accurately calculate its instantaneous power and operating energy consumption, laying a foundation for further reducing the energy consumption of the rail transit system.

Description

Technical Field

[0001] The present invention relates to the technical field of urban rail transit, and particularly to a traction power supply simulation system and a simulation method for urban rail vehicles. Background Art

[0002] Urban rail transit, as an important part of modern urban transportation systems, bears the increasing travel demand. With the acceleration of urbanization, the rail transit system not only faces the problem of overload but also the challenge of energy conservation and emission reduction. In the design and operation of traditional urban rail vehicle power supply systems, there is often a lack of real-time monitoring and evaluation of vehicle operating states, resulting in low operating efficiency, high energy consumption, and increased maintenance costs. In addition, due to the influence of external environmental factors (such as climate change, wind speed change, etc.) on vehicle operating characteristics and power supply requirements, existing power supply simulation technologies have deficiencies in both accuracy and real-time performance. These problems seriously restrict the sustainable development of urban rail transit systems.

[0003] During operation, the traction power supply demand of urban rail vehicles is closely related to their operating states, such as characteristic parameters like vehicle speed, acceleration, mass, frontal area, etc., and state parameters like the inclination gradient of the track. Traditional traction power supply simulation methods often rely on static or simplified models and lack effective adaptability and adjustment capabilities for vehicle operating characteristics in complex dynamic environments. With the progress of rail transit operation technologies, how to establish an efficient, accurate, and dynamic traction power supply simulation method to real-time monitor and calculate vehicle operating energy consumption has become a key technical problem to be urgently solved.

[0004] In the prior art, the published number CN113688541B discloses a traction power supply simulation system and simulation method for an energy storage vehicle in urban rail transit, including the following steps: inputting model parameters; initializing a traction model and a power supply model; setting the simulation time and interval; judging the operating conditions, electrical states of each vehicle, and load conditions of each charging device; determining the operating conditions and electrical states of each vehicle and the load conditions of each charging device; performing traction calculation and power supply calculation on each vehicle; performing load calculation on each charging device; jumping to a time node; judging whether the preset simulation time is reached: if so, outputting the calculation result; if not, updating the operating parameters and continuing the simulation. However, this solution relies on static parameters or empirical data, which may lead to a deviation between the simulation result and the actual situation. The lack of full reflection of the actual operating state and adaptability to environmental changes may affect the accuracy and practicality of the simulation system. Although this solution mentions "judging the operating conditions and electrical states of each vehicle", no specific mechanism is provided to update these states in real time. In a dynamic traffic environment, the operating conditions and electrical states of vehicles may change, and the lack of a dynamic adjustment mechanism may lead to distorted simulation results. For example, the impact of external environmental changes (such as weather, wind speed, etc.) on the electrical states of vehicles is not considered. As a result, the real-time performance and effectiveness of this simulation system are reduced.

[0005] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present disclosure, and thus it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] The purpose of the present invention is to provide a traction power supply simulation system and simulation method for urban rail vehicles to solve the problems raised in the above background art.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A traction power supply simulation system for urban rail vehicles specifically includes:

[0009] An operating parameter acquisition module, which is used to acquire the characteristic parameters of urban rail vehicles and the state parameters during operation, and judge the running state of the train based on the state parameters during operation. The characteristic parameters of urban rail vehicles include the mass of urban rail vehicles and the windward area of rail vehicles, and the state parameters during operation include the rail vehicle speed, vehicle acceleration, and the inclination gradient of the track;

[0010] The instantaneous power calculation module is used to calculate the wind resistance coefficient based on the state parameters during operation and the width of the rail vehicle, characterize the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the rail material, and correct the rolling resistance coefficient through the ambient humidity to obtain the accurate rolling resistance coefficient, and calculate the rolling resistance and air resistance according to the wind resistance coefficient and the accurate rolling resistance coefficient;

[0011] The comprehensive energy consumption analysis module is used to calculate the instantaneous power of the rail vehicle based on the obtained rolling resistance and air resistance, formulate an efficiency adjustment factor according to the vehicle speed and acceleration at different times, calculate the operating energy consumption of the rail vehicle through the instantaneous power of the vehicle and the efficiency adjustment factor, and calculate the comprehensive energy consumption of the rail vehicle based on the operating energy consumption of the rail vehicle and the auxiliary energy consumption of the vehicle;

[0012] The substation loss characterization module is used to calculate the load current of the substation according to the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer, and at the same time collect ambient temperature data to correct the winding resistance and line resistance of the substation transformer, and calculate the line loss and load loss of the substation based on the obtained load current and the corrected winding resistance and line resistance;

[0013] The transmission network consumption summary module is used to calculate the energy consumption of the substation during the operation of the rail vehicle based on the line loss and load loss of the substation, and calculate the transmission network consumption in combination with the comprehensive energy consumption of the rail vehicle.

[0014] Further, the logic for judging the running state of the train based on the state parameters during operation is: calibrate the speed of the rail vehicle at time t as and calibrate the acceleration of the rail vehicle at time t as , where t is the time variable during the operation of the rail vehicle;

[0015] When and , it is judged that the rail vehicle is in the accelerating traction state;

[0016] When and , it is judged that the rail vehicle is in the decelerating braking state;

[0017] When and , it is judged that the rail vehicle is in the uniform running state;

[0018] Among them, is the speed of the rail vehicle at the th moment, that is, the speed of the rail vehicle at the moment before time t.

[0019] Further, based on the state parameters at runtime and the width of the rail vehicle, the wind resistance coefficient is calculated. The logic for calculating the wind resistance coefficient is as follows:

[0020]

[0021] In the formula, is the wind resistance coefficient at time t, is the Reynolds number at time t, is the Reynolds number When it is 2000, the corresponding wind resistance coefficient, where the Reynolds number is calculated based on the width of the rail vehicle and the running speed of the rail vehicle. The specific formula is:

[0022]

[0023] In the formula, is the dynamic viscosity of air, is the air density, is the width of the rail vehicle.

[0024] Further, the rolling resistance coefficient is characterized based on the wheel-rail contact area and the Young's modulus of the track material, and the rolling resistance coefficient is corrected by the environmental humidity. The specific logic is: The wheel-rail contact area is calculated through the wheel width and wheel diameter of the rail vehicle. The formula for calculating the wheel-rail contact area is:

[0025]

[0026] In the formula, is the wheel-rail contact area, is the wheel width of the rail vehicle, is the wheel diameter of the rail vehicle;

[0027] The specific formula for characterizing the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the track material is:

[0028]

[0029] In the formula, is the rolling resistance coefficient, is the mass of the urban rail vehicle, is the friction coefficient between the tire and the track, is the Young's modulus of the track material;

[0030] The rolling resistance coefficient is corrected by the environmental humidity to obtain the accurate rolling resistance coefficient. The specific formula for calculating the accurate rolling resistance coefficient is:

[0031]

[0032] In the formula, is the exact rolling resistance coefficient at time t, is the humidity influence coefficient, is the environmental humidity at time t, is the reference humidity.

[0033] Furthermore, the logic for calculating the rolling resistance and air resistance based on the wind direction resistance coefficient and the exact rolling resistance coefficient is as follows:

[0034] Among them, the air resistance is calculated according to the wind direction resistance coefficient and the frontal area of the rail vehicle. The specific formula is:

[0035]

[0036] In the formula, is the air resistance at time t, is the air density, is the frontal area of the rail vehicle, is the speed of the rail vehicle at time t;

[0037] The formula for calculating the rolling resistance based on the exact rolling resistance coefficient is:

[0038]

[0039] In the formula, is the rolling resistance at time t, is the acceleration due to gravity.

[0040] Furthermore, based on the obtained rolling resistance and air resistance, the instantaneous power of the rail vehicle is calculated. The logic is: based on the obtained rolling resistance and air resistance, the force applied to drive the rail vehicle is obtained, and the energy consumption of the rail vehicle is determined according to the force applied to drive the rail vehicle and the running speed of the rail vehicle. Among them, the formula for calculating the force applied to drive the rail vehicle based on the obtained rolling resistance and air resistance is:

[0041]

[0042] In the formula, is the force applied to the movement of the rail vehicle at time t, is the acceleration of the rail vehicle at time t, is the inclination gradient of the rail vehicle running at time t. Among them, when is greater than or equal to 0, represents the traction force. At this time its value is positive, and the rail vehicle accelerates or travels at a constant speed. When is less than 0, Indicates the braking force, at this time Its value is negative;

[0043] The formula for determining the instantaneous power of a rail vehicle based on the force applied by the movement and the running speed of the rail vehicle is:

[0044]

[0045] In the formula, Is the instantaneous power of the rail vehicle at time t;

[0046] An efficiency adjustment factor is formulated according to the vehicle speed and acceleration at different times. The formula for calculating the running energy consumption of the rail vehicle through the instantaneous power of the vehicle and the efficiency adjustment factor is:

[0047]

[0048] In the formula, Is the running energy consumption of the rail vehicle, Is the total running time of the rail vehicle, Is the efficiency adjustment factor, where the efficiency adjustment factor The formula it is based on is:

[0049]

[0050] In the formula, And Are the maximum and minimum efficiencies of the rail vehicle traction motor in the acceleration and deceleration states respectively, Is the reference speed;

[0051] Based on the running energy consumption of the rail vehicle and the auxiliary energy consumption of the vehicle, the comprehensive energy consumption of the rail vehicle is calculated. The auxiliary energy consumption of the vehicle includes the energy consumed by air conditioning and lighting. Then the comprehensive energy consumption of the rail vehicle is:

[0052]

[0053] In the formula, Is the comprehensive energy consumption of the rail vehicle, Is the auxiliary energy consumption of the vehicle.

[0054] Furthermore, according to the comprehensive energy consumption of the rail vehicle combined with the rated voltage of the substation transformer, the load current of the substation is calculated. The formula for calculating the load current of the substation is:

[0055]

[0056] In the formula, Is the load current of the substation, Is the rated voltage of the transformer;

[0057] Collect the ambient temperature data to correct the winding resistance and line resistance of the substation transformer. The specific formula is as follows:

[0058]

[0059]

[0060] In the formula, and are the corrected winding resistance and line resistance of the transformer at time t, and are the calibrated winding resistance and calibrated line resistance of the transformer respectively, and are the temperature coefficients of the winding resistance material and the line resistance material respectively, and are the current ambient temperature and the standard reference temperature respectively;

[0061] Based on the obtained load current and the corrected winding resistance and line resistance, the formulas for calculating the line loss and load loss of the substation are as follows:

[0062]

[0063]

[0064] In the formula, and are the load loss of the substation at time t and the line loss of the substation respectively;

[0065] Based on the line loss and load loss of the substation, calculate the energy consumption of the substation during the operation of the rail vehicle. Combine the comprehensive energy consumption of the rail vehicle to calculate the power grid consumption. The specific formula for calculating the power grid consumption is as follows:

[0066]

[0067] In the formula, is the power grid consumption.

[0068] The present invention also provides a traction power supply simulation method for an urban rail vehicle. The traction power supply simulation method for an urban rail vehicle is used to control the above-mentioned traction power supply simulation system for an urban rail vehicle. The specific steps include:

[0069] Collect the characteristic parameters of urban rail vehicles and the state parameters during operation, and judge the running state of the train based on the state parameters during operation. The characteristic parameters of the urban rail vehicle include the mass of the urban rail vehicle and the windward area of the rail vehicle. The state parameters during operation include the rail vehicle speed, vehicle acceleration, and the inclination gradient of the track.

[0070] Based on the state parameters during operation and combined with the rail vehicle width, calculate the wind resistance coefficient. Characterize the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the track material, and correct the rolling resistance coefficient through the environmental humidity to obtain the accurate rolling resistance coefficient. Calculate the rolling resistance and air resistance according to the wind resistance coefficient and the accurate rolling resistance coefficient.

[0071] Calculate the instantaneous power of the rail vehicle based on the obtained rolling resistance and air resistance. Develop an efficiency adjustment factor according to the vehicle speed and acceleration at different times. Calculate the operating energy consumption of the rail vehicle through the instantaneous power of the vehicle and the efficiency adjustment factor. Based on the operating energy consumption of the rail vehicle and the auxiliary energy consumption of the vehicle, calculate the comprehensive energy consumption of the rail vehicle.

[0072] According to the comprehensive energy consumption of the rail vehicle and combined with the rated voltage of the substation transformer, calculate the load current of the substation. At the same time, collect environmental temperature data to correct the winding resistance and line resistance of the substation transformer. Based on the obtained load current and the corrected winding resistance and line resistance, calculate the line loss and load loss of the substation.

[0073] Based on the line loss and load loss of the substation, calculate the energy consumption of the substation during the operation of the rail vehicle, and calculate the power grid consumption in combination with the comprehensive energy consumption of the rail vehicle.

[0074] Compared with the prior art, the beneficial effects of the present invention are:

[0075] By collecting the characteristic parameters of urban rail vehicles and the state parameters during operation, and combining dynamic environmental factors, a systematic traction power supply simulation method is constructed. Through the accurate judgment and real-time monitoring of the vehicle running state, the rolling resistance and air resistance of the vehicle can be effectively calculated, so as to accurately calculate its instantaneous power and operating energy consumption. It not only improves the operation efficiency of the rail transit system, but also significantly reduces the energy consumption and operation cost. In addition, based on the comprehensive calculation of the vehicle operating energy consumption and auxiliary energy consumption, combined with the load current of the substation and the corrected winding resistance and line resistance, the energy consumption situation of the substation can be effectively evaluated and optimized. This real-time energy consumption analysis method helps to further reduce the energy consumption of the rail transit system, while improving the adaptability and stability to the power grid load, and ultimately making the urban rail transit more efficient, economical and environmentally friendly. Brief Description of the Drawings

[0076] Figure 1 Schematic diagram of the overall system structure of the present invention;

[0077] Figure 2 Schematic diagram of the overall method flow of the present invention. Detailed implementation manners

[0078] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific embodiments.

[0079] It should be noted that unless otherwise defined, the technical terms or scientific terms used in the present invention should have the ordinary meanings understood by those with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left", "right" are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0080] Embodiment:

[0081] Please refer to Figure 1 , the present invention provides a technical solution:

[0082] A traction power supply simulation system for urban rail vehicles, specifically including:

[0083] An operating parameter acquisition module, configured to acquire the characteristic parameters of urban rail vehicles and the state parameters during operation, and judge the operating state of the train based on the state parameters during operation. The characteristic parameters of the urban rail vehicle include the mass of the urban rail vehicle and the windward area of the rail vehicle, and the state parameters during operation include the rail vehicle speed, vehicle acceleration, and the inclination gradient of the track; ]>

[0084] The logic for judging the operating state of the train based on the state parameters during operation is: calibrate the speed of the rail vehicle at time t as calibrate the acceleration of the rail vehicle at time t as , where t is the time variable during the operation of the rail vehicle;

[0085] When , and at the same time, it is judged that the rail vehicle is in the acceleration traction state;

[0086] When and When, it is determined that the rail vehicle is in a decelerating braking state;

[0087] When and When, it is determined that the rail vehicle is in a uniform motion state;

[0088] Among them, is the speed of the rail vehicle at the moment, that is, the speed of the rail vehicle at the moment before the t moment. The moment and The acquisition interval time of the moment is generally greater than 0 and less than 0.5 seconds, and can be set according to actual needs. Among them, the mass of urban rail vehicles can be obtained during the vehicle design and production stages. Manufacturers usually provide vehicle mass data, including the mass of the empty vehicle and the fully loaded vehicle. These data can be found in the vehicle's technical manual or instruction manual.

[0089] The windward area can be calculated from the vehicle's design drawings or CAD model, usually involving the lateral and front projection areas of the vehicle. During the vehicle design stage, the windward area of the vehicle can be measured through wind tunnel tests.

[0090] The method for obtaining the running speed of the rail vehicle is as follows: Speed sensors (such as encoders or speedometers) are usually installed on the vehicle to monitor the running speed of the vehicle in real time. Or speed detectors set on the track can transmit data to the monitoring system through wireless signals to record the running speed of each train.

[0091] The running acceleration can be in the vehicle's control system. The dynamic accelerometer can measure the acceleration of the vehicle in real time and feed the data back to the vehicle monitoring system.

[0092] The inclination gradient of the track can be obtained through track sensors. By installing inclination sensors or terrain sensors on the track, the inclination gradient of the track can be monitored in real time and the data can be transmitted to the operation control system. Using an inertial measurement unit (IMU) combined with GPS, the inclination information of the track can be obtained, and the accuracy of the data can be improved through multi-sensor fusion technology.

[0093] The instantaneous power calculation module is used to calculate the windward resistance coefficient based on the state parameters during operation in combination with the width of the rail vehicle, characterize the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the track material, and correct the rolling resistance coefficient through the environmental humidity to obtain an accurate rolling resistance coefficient, and calculate the rolling resistance and air resistance according to the windward resistance coefficient and the accurate rolling resistance coefficient;

[0094] Based on the state parameters during operation in combination with the width of the rail vehicle, calculate the windward resistance coefficient. The logic for calculating the windward resistance coefficient is as follows:

[0095]

[0096] In the formula, is the wind direction resistance coefficient at time t, is the Reynolds number at time t, is the Reynolds number is the corresponding wind direction resistance coefficient when the Reynolds number is 2000, where the Reynolds number is calculated based on the width of the rail vehicle and the running speed of the rail vehicle. The specific formula is:

[0097]

[0098] In the formula, is the dynamic viscosity of air, usually at 1.81 × 10⁻ 5 kg / (m·s), is the air density, usually taken as about 1.225 kg / m³ (under standard conditions at sea level), is the width of the rail vehicle.

[0099] The Reynolds number is a very important dimensionless quantity in fluid dynamics, which is used to describe the influence of the flow state (laminar flow or turbulent flow) on fluid motion and resistance. may vary with the Reynolds number. The common empirical relationships are as follows: In laminar flow (usually ), usually decreases with the increase of the Reynolds number.

[0100] In the turbulent state (usually ), is a relatively constant value, but it will vary slightly with the change of the Reynolds number until a stable value is reached.

[0101] The rolling resistance coefficient is characterized based on the wheel-rail contact area and the Young's modulus of the rail material, and is corrected by the environmental humidity. The specific logic is: The wheel-rail contact area is calculated through the wheel width and wheel diameter of the rail vehicle. The formula for calculating the wheel-rail contact area is:

[0102]

[0103] In the formula, is the wheel-rail contact area, is the wheel width of the rail vehicle, is the wheel diameter of the rail vehicle; the wheel width is the lateral dimension where the wheel contacts the rail, which determines the width of the contact area. The wheel diameter is the diameter of the wheel, which affects the longitudinal dimension of the contact area. The "0.2" in the formula is an empirical coefficient, usually determined through experimental data or literature. This coefficient reflects the actual characteristics of the contact area between the wheel and the rail under actual operating conditions. The contact between the wheel and the rail is not a simple rectangle or circle, but a deformed contact area formed under force. The contact area varies due to pressure and the material properties of the wheel, and this coefficient is a generalization of these effects. In actual tests, by measuring the rolling resistance under different conditions, the actual contact area is calculated, and then the empirical coefficient is obtained.

[0104] The way to obtain the wheel width is as follows: The wheel width is usually the wheel axle specification parameter provided by the manufacturer, or obtained by measuring the actual vehicle. The wheel width of standard rail vehicles may be within a certain range (for example, the common wheel width of rail vehicles is generally between 0.15 m and 0.25 m). The wheel diameter is also usually the parameter provided by the manufacturer, or obtained by actual measurement. The unit of the wheel diameter is usually in meters, and the common wheel diameter of rail vehicles is generally between 0.6 m and 1.2 m, depending on the design and type of the vehicle.

[0105] The specific formula for characterizing the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the rail material is:

[0106]

[0107] In the formula, is the rolling resistance coefficient, is the mass of the urban rail vehicle, is the friction coefficient between the tire and the rail, is the Young's modulus of the rail material;

[0108] The mass of the vehicle directly affects the normal force between the wheel and the rail. The greater the normal force, the greater the friction force will be. Therefore, the greater the mass of the vehicle, the greater the rolling resistance. In the numerator, the mass represents the gravity of the vehicle, which is proportional to the generated friction force. The friction force is one of the main factors to overcome the rolling resistance.

[0109] The friction coefficient is a dimensionless quantity that describes the ratio of the friction force to the normal force between two contact surfaces. It reflects the friction performance between the tire and the rail and is affected by materials, surface conditions, and environmental conditions. In the numerator, the friction coefficient represents the friction force related to the vehicle movement. The higher the friction coefficient, the greater the rolling resistance.

[0110] The contact area is the size of the contact region between the wheel and the track. The larger the contact area, the smaller the pressure per unit area, so the overall frictional force may decrease. In the denominator, the contact area increases, which leads to a decrease in the rolling resistance coefficient . This is because the increased contact area can disperse the normal force, thereby reducing the pressure per unit area and the corresponding frictional force.

[0111] Young's modulus is an index of the stiffness of a material, indicating the elastic deformation ability of the material under stress. The Young's modulus of the track material is closely related to the degree of deformation of the wheel under force. In the denominator, the Young's modulus affects the rolling resistance by influencing the deformation of the track. A higher Young's modulus means greater material rigidity and less deformation. Therefore, under the same load conditions, the rolling resistance coefficient will be relatively lower.

[0112] where the friction coefficient between the tire and the track can be directly measured through experiments. A friction testing machine can be used to simulate the contact conditions between the tire and the track, record the frictional force and normal force under different loads, and thus calculate the friction coefficient , or refer to relevant research papers and technical reports to find friction coefficient data under similar conditions.

[0113] The Young's modulus of the track material can be found by referring to relevant material standards and engineering manuals. Usually, the standard Young's modulus values of track materials (such as steel, concrete, etc.) can be obtained. For example, the Young's modulus of steel is usually around 200 GPa, while that of concrete is generally between 25 GPa and 30 GPa.

[0114] The rolling resistance coefficient is corrected by environmental humidity to obtain the accurate rolling resistance coefficient. The specific formula for calculating the accurate rolling resistance coefficient is:

[0115]

[0116] where, is the accurate rolling resistance coefficient at time t, is the humidity influence coefficient, is the environmental humidity at time t, is the reference humidity.

[0117] Under high humidity conditions, especially in rainy or humid environments, the contact surface between the tire and the track may be covered by a water film. In this case, the water film will reduce the frictional force, resulting in a decrease in the friction coefficient and thus the rolling resistance coefficient may decrease. The presence of the water film can change the contact nature between the tire and the track, forming a hydrodynamic effect, which often leads to a reduction in the frictional force.

[0118] Humidity influence coefficient It is set to represent the influence of humidity on the rolling resistance coefficient. By conducting field tests under different humidity conditions, the rolling resistance coefficient of the rail vehicle is measured. In these tests, the influence of humidity on the rolling resistance is recorded, and the range of the humidity influence coefficient is obtained through statistical analysis. At the same time, based on the experience accumulated by those skilled in the art during long-term practical work, the range of the humidity influence coefficient is generally between 0 and 0.5.

[0119] The logic for calculating the rolling resistance and air resistance based on the wind direction resistance coefficient and the precise rolling resistance coefficient is as follows:

[0120] Among them, the air resistance is calculated based on the wind direction resistance coefficient and the frontal area of the rail vehicle. The specific formula is:

[0121]

[0122] In the formula, is the air resistance at time t, is the air density, is the frontal area of the rail vehicle, is the speed of the rail vehicle at time t;

[0123] The formula for calculating the rolling resistance based on the precise rolling resistance coefficient is:

[0124]

[0125] In the formula, is the rolling resistance at time t, is the acceleration due to gravity.

[0126] The comprehensive energy consumption analysis module is used to calculate the instantaneous power of the rail vehicle based on the obtained rolling resistance and air resistance, formulate an efficiency adjustment factor according to the vehicle speed and acceleration at different times, calculate the operating energy consumption of the rail vehicle through the instantaneous power and efficiency adjustment factor of the vehicle, and calculate the comprehensive energy consumption of the rail vehicle based on the operating energy consumption and auxiliary energy consumption of the vehicle;

[0127] The logic for calculating the instantaneous power of the rail vehicle based on the obtained rolling resistance and air resistance is as follows: The force applied to drive the rail vehicle to move is obtained based on the obtained rolling resistance and air resistance, and the energy consumption of the rail vehicle is determined according to the force applied to drive the rail vehicle to move and the operating speed of the rail vehicle. Among them, the formula for calculating the force applied to drive the rail vehicle to move based on the obtained rolling resistance and air resistance is:

[0128]

[0129] Wherein, is the force exerted on the rail vehicle at time t, is the acceleration of the rail vehicle at time t, is the inclination of the rail vehicle at time t, where when is greater than or equal to 0, represents the traction force, and at this time its value is positive, and the rail vehicle accelerates or travels at a constant speed. When is less than 0, represents the braking force, and at this time its value is negative;

[0130] The formula for determining the instantaneous power of the rail vehicle based on the force exerted by the movement and the running speed of the rail vehicle is:

[0131]

[0132] Wherein, is the instantaneous power of the rail vehicle at time t;

[0133] The formula for calculating the running energy consumption of the rail vehicle by the instantaneous power of the vehicle and the efficiency adjustment factor by formulating the efficiency adjustment factor according to the vehicle speed and acceleration at different times is:

[0134]

[0135] Wherein, is the running energy consumption of the rail vehicle, is the total running time of the rail vehicle, is the efficiency adjustment factor, where the efficiency adjustment factor is based on the formula:

[0136]

[0137] Wherein, and are the maximum and minimum efficiencies of the traction motor of the rail vehicle in the acceleration and deceleration states respectively, is the reference speed;

[0138] Among them, the reference speed can be set according to actual needs, and the general range is: to .

[0139] In the uniform motion state, the acceleration of the train is close to zero, which represents that the train is traveling at a stable speed. In this case, the energy usage efficiency is relatively high, so the efficiency adjustment factor is set to: .

[0140] Under acceleration, the train needs to overcome more resistance (such as air resistance, rolling resistance, etc.), and the efficiency of the traction system usually decreases. To describe this phenomenon, the efficiency adjustment factor is: , is an exponential decay function. As the speed deviates from the reference speed , the efficiency will show a non-linear decline. When the train speed is far from the reference speed, the energy loss will increase rapidly, resulting in a decrease in efficiency. This setting reflects the non-linear characteristics in reality: when accelerating at high speed, the efficiency of the motor and other systems may decrease significantly.

[0141] Under deceleration, the train reduces its speed through braking. The situation of energy loss is similar to that of acceleration, but usually the efficiency is lower because not all energy can be effectively regenerated during braking. Especially when using mechanical braking, the energy cannot be fully fed back to the power grid. For example, air braking and friction braking will cause energy to be lost in the form of heat. At this time, the setting of the efficiency adjustment factor is: , and the decay function is the same as that during acceleration, indicating that the energy loss during deceleration is also related to the degree of speed deviation from the reference speed.

[0142] The maximum efficiency during acceleration can be obtained by experimentally measuring the input power and output power under specific conditions. The specific steps include: recording the input power (such as current, voltage, rotational speed, etc.) and output power (such as mechanical power, kinetic energy, etc.). Using computer-aided design (CAD) or simulation software to model the system and analyze the efficiency under different working conditions. For electric motors and drive systems, the maximum efficiency is usually between 85% and 95%. For internal combustion engines, the maximum efficiency may be around 25% to 40% due to its thermal efficiency limitation.

[0143] The minimum efficiency during deceleration. The minimum efficiency usually represents the lowest energy conversion efficiency that the system can achieve under deceleration or braking conditions. This reflects the limitations of energy recovery and energy loss. For the regenerative braking system of electric vehicles, the minimum efficiency may be between 60% and 80%, and the specific value depends on the design and material characteristics of the braking system. For mechanical braking systems, the minimum efficiency may be even lower, usually around 30% to 50% because a large amount of energy is lost in the form of heat during braking.

[0144] Based on the operating energy consumption of the rail vehicle and the auxiliary energy consumption of the vehicle, the comprehensive energy consumption of the rail vehicle is calculated. The auxiliary energy consumption of the vehicle includes the energy consumed by air conditioning and lighting. Then the comprehensive energy consumption of the rail vehicle is:

[0145]

[0146] In the formula, is the comprehensive energy consumption of the rail vehicle, Auxiliary energy consumption of the vehicle

[0147] Among them, the auxiliary energy consumption of the vehicle is expressed as the sum of the energy consumption of the air-conditioning system and the lighting energy consumption. Among them, the energy consumption of the air-conditioning system is obtained by calculating the basic energy consumption of the air-conditioning system and the additional energy consumption brought by the increase in the number of passengers, combined with the number of passengers;

[0148] The lighting energy consumption is calculated by the number of lighting fixtures and the energy consumption of each fixture.

[0149] Substation loss characterization module, which is used to calculate the load current of the substation according to the comprehensive energy consumption of the rail vehicle combined with the rated voltage of the substation transformer, and at the same time collect ambient temperature data to correct the winding resistance and line resistance of the substation transformer. Based on the obtained load current and the corrected winding resistance and line resistance, calculate the line loss and load loss of the substation;

[0150] According to the comprehensive energy consumption of the rail vehicle combined with the rated voltage of the substation transformer, calculate the load current of the substation. The formula for calculating the load current of the substation is:

[0151]

[0152] In the formula, is the load current of the substation at time t, is the rated voltage of the transformer;

[0153] Collect ambient temperature data to correct the winding resistance and line resistance of the substation transformer. The specific formula is:

[0154]

[0155]

[0156] In the formula, and are the corrected winding resistance and line resistance of the transformer at time t, and are the calibrated winding resistance and calibrated line resistance of the transformer respectively, and are the temperature coefficients of the winding resistance material and the line resistance material respectively, and are the current ambient temperature and the standard reference temperature respectively;

[0157] Among them, the reference standard temperature is usually 20 or 25 , the temperature coefficient of the winding resistance and the temperature coefficient of the line resistance It represents the sensitivity of the resistance of the material to temperature change. Generally, metallic materials (such as copper and aluminum) have a positive temperature coefficient. The transformer winding is usually made of a metal with good electrical conductivity (such as copper or aluminum), and its temperature coefficient is usually between 0.00393 / (copper) to 0.0039 / (aluminum). The line resistance will also increase with the increase of temperature and has a similar temperature coefficient.

[0158] Based on the obtained load current, the corrected winding resistance and line resistance, the formulas for calculating the line loss and load loss of the substation are as follows:

[0159]

[0160]

[0161] In the formula, and are the load loss of the substation at time t and the line loss of the substation respectively;

[0162] The transmission grid consumption summary module is used to calculate the energy consumption of the substation during the operation of the rail vehicle based on the line loss and load loss of the substation, and combine the comprehensive energy consumption of the rail vehicle to calculate the transmission grid consumption.

[0163] Based on the line loss and load loss of the substation, calculate the energy consumption of the substation during the operation of the rail vehicle, and combine the comprehensive energy consumption of the rail vehicle to calculate the transmission grid consumption. The specific formula for calculating the transmission grid consumption is as follows:

[0164]

[0165] In the formula, is the transmission grid consumption.

[0166] Please refer to Figure 2 , the present invention also provides a traction power supply simulation method for an urban rail vehicle. The traction power supply simulation method for an urban rail vehicle is used to control the above-mentioned traction power supply simulation system for an urban rail vehicle. The specific steps include:

[0167] Step 1: Collect the characteristic parameters of the urban rail vehicle and the state parameters during operation, and judge the running state of the train based on the state parameters during operation. The characteristic parameters of the urban rail vehicle include the mass of the urban rail vehicle and the windward area of the rail vehicle, and the state parameters during operation include the rail vehicle speed, vehicle acceleration, and the slope of the track;

[0168] Step 2: Calculate the wind resistance coefficient based on the runtime status parameters in combination with the width of the rail vehicle. Characterize the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the rail material, and correct the rolling resistance coefficient through the ambient humidity to obtain the accurate rolling resistance coefficient. Calculate the rolling resistance and air resistance based on the wind resistance coefficient and the accurate rolling resistance coefficient;

[0169] Step 3: Calculate the instantaneous power of the rail vehicle based on the obtained rolling resistance and air resistance. Develop an efficiency adjustment factor according to the vehicle speed and acceleration at different times. Calculate the operating energy consumption of the rail vehicle through the instantaneous power of the vehicle and the efficiency adjustment factor. Calculate the comprehensive energy consumption of the rail vehicle based on the operating energy consumption of the rail vehicle and the auxiliary energy consumption of the vehicle;

[0170] Step 4: Calculate the load current of the substation according to the comprehensive energy consumption of the rail vehicle in combination with the rated voltage of the substation transformer. At the same time, collect ambient temperature data to correct the winding resistance and line resistance of the substation transformer. Calculate the line loss and load loss of the substation based on the obtained load current and the corrected winding resistance and line resistance;

[0171] Step 5: Calculate the energy consumption of the substation during the operation of the rail vehicle based on the line loss and load loss of the substation. Calculate the power grid consumption in combination with the comprehensive energy consumption of the rail vehicle.

[0172] The above formulas are all calculated by taking the numerical values after dimensionless. The formula is a formula obtained by software simulation through collecting a large amount of data to approximate the real situation. The preset parameters in the formula are set by those skilled in the art according to the actual situation.

[0173] The above embodiments can be implemented in whole or in part by software, hardware, firmware, or any other combination. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by the combination of computer software and electronic hardware. Whether these functions are executed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0174] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, and may be located in one place, or may be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0175] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application.

Claims

1. A traction power supply simulation system for urban rail vehicles, characterized in that, Specifically, it includes: An operating parameter acquisition module, which is used to acquire the characteristic parameters of urban rail vehicles and the state parameters during operation, and judge the running state of the train based on the state parameters during operation. The characteristic parameters of the urban rail vehicle include the mass of the urban rail vehicle and the windward area of the rail vehicle, and the state parameters during operation include the rail vehicle speed, vehicle acceleration, and the inclination gradient of the track; An instantaneous resistance power calculation module, which is used to calculate the windward resistance coefficient based on the state parameters during operation combined with the width of the rail vehicle, characterize the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the track material, and correct the rolling resistance coefficient through the environmental humidity to obtain an accurate rolling resistance coefficient, and calculate the rolling resistance and air resistance according to the windward resistance coefficient and the accurate rolling resistance coefficient; Characterize the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the track material, and correct the rolling resistance coefficient through the environmental humidity. The specific logic is as follows: calculate the wheel-rail contact area through the wheel width and wheel diameter of the rail vehicle. The formula for calculating the wheel-rail contact area is: A1 = W * 0.2 * D In the formula, A1 is the wheel-rail contact area, W is the wheel width of the rail vehicle, and D is the wheel diameter of the rail vehicle; The specific formula for characterizing the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the track material is: Where C r is the rolling resistance coefficient, M is the mass of the urban rail vehicle, μ f is the friction coefficient between the tire and the track, and E is the Young's modulus of the track material; Correct the rolling resistance coefficient through the environmental humidity to obtain an accurate rolling resistance coefficient. The specific formula for calculating the accurate rolling resistance coefficient is: C′ r C(t) = C r *{1 - h*(H(t) - H0)} where C′ r (t) is the exact rolling resistance coefficient at time t, h is the humidity influence coefficient, H(t) is the environmental humidity at time t, and H0 is the reference humidity; The logic for calculating the rolling resistance and air resistance according to the windward resistance coefficient and the accurate rolling resistance coefficient is: Among them, calculate the air resistance according to the windward resistance coefficient and the windward area of the rail vehicle. The specific formula is: where F drag (t) is the air resistance at time t, ρ is the air density, A drag is the frontal area of the rail vehicle, and V(t) is the speed of the rail vehicle at time t; The formula for calculating the rolling resistance according to the accurate rolling resistance coefficient is: F roll C′(t) r *M*g*C′(t) where F roll (t) is the rolling resistance at time t, and g is the acceleration due to gravity; A comprehensive energy consumption analysis module, which is used to calculate the instantaneous power of the rail vehicle based on the obtained rolling resistance and air resistance, formulate an efficiency adjustment factor according to the vehicle speed and acceleration at different times, calculate the running energy consumption of the rail vehicle through the instantaneous power of the vehicle and the efficiency adjustment factor, and calculate the comprehensive energy consumption of the rail vehicle based on the running energy consumption of the rail vehicle and the auxiliary energy consumption of the vehicle; The logic for calculating the instantaneous power of the rail vehicle based on the obtained rolling resistance and air resistance is: obtain the force applied to drive the movement of the rail vehicle based on the obtained rolling resistance and air resistance, and determine the energy consumption of the rail vehicle according to the force applied to drive the movement of the rail vehicle and the running speed of the rail vehicle. Among them, the formula for calculating the force applied to drive the movement of the rail vehicle based on the obtained rolling resistance and air resistance is: F tra F(t) = M * a(t) + M * g * sinθ(t) + F drag F(t) + F roll F(t) Where, F tra (t) is the force exerted by the moving rail vehicle at time t, a(t) is the acceleration of the rail vehicle at time t, and θ(t) is the inclination of the running rail vehicle at time t. Among them, when a(t) is greater than or equal to 0, F tra (t) represents the traction force, and at this time F tra its value is positive, and the rail vehicle is accelerating or moving at a constant speed. When a(t) is less than 0, F tra (t) represents the braking force, and at this time F tra its value is negative; The formula for determining the instantaneous power of the rail vehicle according to the force applied to the movement and the running speed of the rail vehicle is: P tra (t) = F tra (t) * V(t) Where, P tra (t) is the instantaneous power of the rail vehicle at time t; The formula for formulating an efficiency adjustment factor according to the vehicle speed and acceleration at different times and calculating the running energy consumption of the rail vehicle through the instantaneous power of the vehicle and the efficiency adjustment factor is: where, E tra is the operating energy consumption of the rail vehicle, T is the total operating time of the rail vehicle, is the efficiency adjustment factor, and the formula for the efficiency adjustment factor is as follows: In the formula, and are the maximum and minimum efficiencies of the traction motor of the rail vehicle in the acceleration and deceleration states respectively, and V ref is the reference speed; Based on the running energy consumption of the rail vehicle and the auxiliary energy consumption of the vehicle, the comprehensive energy consumption of the rail vehicle is calculated, where the auxiliary energy consumption of the vehicle includes the energy consumed by air conditioning and lighting. Then the comprehensive energy consumption of the rail vehicle is as follows: E ve = E tra + E sta where E ve is the comprehensive energy consumption of the rail vehicle, and E sta is the auxiliary energy consumption of the vehicle; The substation loss characterization module is used to calculate the load current of the substation according to the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer. At the same time, environmental temperature data is collected to correct the winding resistance and line resistance of the substation transformer. Based on the obtained load current and the corrected winding resistance and line resistance, the line loss and load loss of the substation are calculated; The transmission grid consumption summary module is used to calculate the energy consumption of the substation during the operation of the rail vehicle based on the line loss and load loss of the substation, and calculate the transmission grid consumption by combining the comprehensive energy consumption of the rail vehicle.

2. The traction power supply simulation system of an urban rail vehicle according to claim 1, characterized in that: The logic for judging the running state of the train based on the state parameters during operation is: calibrate the speed of the rail vehicle at time t as V(t), and calibrate the acceleration of the rail vehicle at time t as a(t), where t is the time variable during the operation of the rail vehicle; When V(t) - V(t - 1) > 0 and a(t) > 0, it is judged that the rail vehicle is in the accelerating traction state; When V(t) - V(t - 1) < 0 and a(t) < 0, it is judged that the rail vehicle is in the decelerating braking state; When V(t) - V(t - 1) = 0 and a(t) = 0, it is judged that the rail vehicle is in the uniform running state; Among them, V(t - 1) is the speed of the rail vehicle at the (t - 1)th moment, that is, the speed of the rail vehicle at the moment before the tth moment.

3. The traction power supply simulation system for an urban rail vehicle according to claim 2, characterized in that: Based on the state parameters during operation and the width of the rail vehicle, the wind resistance coefficient is calculated. The logic for calculating the wind resistance coefficient is as follows: Where, C d (t) is the wind direction resistance coefficient at time t, Re(t) is the Reynolds number at time t, C d1 is the wind direction resistance coefficient corresponding to when the Reynolds number Re(t) is 2000, where the Reynolds number Re(t) is calculated based on the width of the rail vehicle and the running speed of the rail vehicle, and the specific formula it is based on is: In the formula, μ is the dynamic viscosity of air, ρ is the air density, and L is the width of the rail vehicle.

4. A traction power supply simulation system for an urban rail vehicle according to claim 1, characterized in that: According to the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer, the load current of the substation is calculated. The formula for calculating the load current of the substation is: In the formula, I(t) is the load current of the substation, and Y is the rated voltage of the transformer; Environmental temperature data is collected to correct the winding resistance and line resistance of the substation transformer. The specific formula is: R′ r R(t) = R r *{1 + α*(Z(t) - Z ref )} R′ x (t) = R x *{1 + β*(Z(t) - Z ref )} wherein, R' r (t) and R' x (t) are respectively the winding resistance and line resistance of the transformer at time t after correction, R r and R x are respectively the calibrated winding resistance and calibrated line resistance of the transformer, α and β are respectively the temperature coefficients of the winding resistance material and the line resistance material, Z(t) and Z ref are respectively the current ambient temperature and the standard reference temperature; Based on the obtained load current and the corrected winding resistance and line resistance, the formula for calculating the line loss and load loss of the substation is: P load P(t) = I(t) * R' r P(t) 2 P loss P(t) = I(t) * R' x P(t) 2 Where, P load (t) and P loss (t) are the load loss of the substation at time t and the line loss of the substation, respectively; Based on the line loss and load loss of the substation, the energy consumption of the substation during the operation of the rail vehicle is calculated, and the transmission grid consumption is calculated by combining the comprehensive energy consumption of the rail vehicle. The specific formula for calculating the transmission grid consumption is: E all = E ve + ∫₀ T P load (t) + P loss (t) dt where E all is the consumption of the power transmission network.

5. A traction power supply simulation method for urban rail vehicles, characterized in that: The traction power supply simulation method of an urban rail vehicle is used to control the traction power supply simulation system of the urban rail vehicle according to any one of claims 1 - 4. The specific steps include: Collect the characteristic parameters of the urban rail vehicle and the state parameters during operation, and judge the running state of the train based on the state parameters during operation. The characteristic parameters of the urban rail vehicle include the mass of the urban rail vehicle and the windward area of the rail vehicle, and the state parameters during operation include the rail vehicle speed, vehicle acceleration, and track slope; Calculate the wind resistance coefficient based on the state parameters at runtime combined with the width of the rail vehicle, characterize the rolling resistance coefficient based on the wheel-rail contact area and the Young's modulus of the rail material, and correct the rolling resistance coefficient through the ambient humidity to obtain the accurate rolling resistance coefficient. Calculate the rolling resistance and air resistance according to the wind resistance coefficient and the accurate rolling resistance coefficient; Calculate the instantaneous power of the rail vehicle based on the obtained rolling resistance and air resistance, formulate an efficiency adjustment factor according to the vehicle speed and acceleration at different times, calculate the operating energy consumption of the rail vehicle through the instantaneous power of the vehicle and the efficiency adjustment factor, and calculate the comprehensive energy consumption of the rail vehicle based on the operating energy consumption of the rail vehicle and the auxiliary energy consumption of the vehicle; Calculate the load current of the substation according to the comprehensive energy consumption of the rail vehicle combined with the rated voltage of the substation transformer. At the same time, collect the ambient temperature data to correct the winding resistance and line resistance of the substation transformer. Calculate the line loss and load loss of the substation based on the obtained load current and the corrected winding resistance and line resistance; Calculate the energy consumption of the substation during the operation of the rail vehicle based on the line loss and load loss of the substation, and calculate the power grid consumption in combination with the comprehensive energy consumption of the rail vehicle.

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