Traction power supply simulation system and simulation method of urban rail vehicle

Abstract

The invention discloses a traction power supply simulation system and simulation method for an urban rail vehicle, and relates to the technical field of urban rail transit. Comprising an operation parameter acquisition module used for acquiring urban rail vehicle characteristic parameters and operation state parameters; the hindering instantaneous power calculation module is used for calculating and representing a wind direction resistance coefficient and a rolling resistance coefficient and correcting the rolling resistance coefficient through environment humidity so as to calculate rolling resistance and air resistance; the comprehensive energy consumption analysis module is used for calculating the instantaneous power of the vehicle and the operation energy consumption of the railway vehicle; the transformer substation loss characterization module is used for calculating line loss and load loss of the transformer substation according to the comprehensive energy consumption of the railway vehicle; and the power transmission network consumption summarization module is used for obtaining power transmission network consumption. The rolling resistance and the air resistance of the vehicle can be effectively calculated, so that the instantaneous power and the operation energy consumption of the vehicle can be accurately calculated, and a foundation is laid for further reducing the energy consumption of a rail transit system.

Description

Technical Field

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

[0002] Urban rail transit, as an important part of the modern urban transportation system, carries the growing travel demand. With the acceleration of urbanization, the rail transit system is not only facing the problem of overload, but also the challenge of energy conservation and emission reduction. In the design and operation process of traditional urban rail vehicle power supply systems, there is often a lack of real-time monitoring and evaluation of the vehicle's operating status, 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 changes, etc.) on the vehicle's operating characteristics and power supply requirements, the existing power supply simulation technology is insufficient in accuracy and real-time performance. These problems seriously restrict the sustainable development of the urban rail transit system.

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

[0004] In the prior art, the publication number CN113688541B discloses a traction power supply simulation system and simulation method for energy storage vehicles in urban rail transit, including the following steps: input model parameters; initialize traction model and power supply model; set simulation time and interval; judge the operating conditions, electrical status and load conditions of each vehicle; determine the operating conditions and electrical status of each vehicle and the load conditions of each charging device; perform traction calculation and power supply calculation for each vehicle; perform load calculation for each charging device; jump to the time node; judge whether the preset simulation time is reached: if so, output the calculation result; if not, update the operating parameters and continue the simulation. However, this scheme relies on static parameters or empirical data, which may cause the simulation results to deviate from the actual situation. The lack of full reflection of the actual operating status and adaptability to environmental changes may affect the accuracy and practicality of the simulation system. Although this scheme mentions "judging the operating conditions and electrical status 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 status of the vehicle may change, and the lack of a dynamic adjustment mechanism may cause distortion of the simulation results. For example, the impact of external environmental changes (such as weather, wind speed, etc.) on the electrical state of the vehicle is not considered, which reduces the real-time performance and effectiveness of the simulation system.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

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

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

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

[0009] An operation parameter acquisition module is used to collect characteristic parameters of urban rail vehicles and state parameters during operation, and judge the operation state of the train based on the state parameters during operation, wherein the characteristic parameters of urban rail vehicles include the mass of urban rail vehicles and the frontal area of ​​rail vehicles, and the state parameters during operation include rail vehicle speed, vehicle acceleration and track inclination gradient;

[0010] The instantaneous power calculation module is used to calculate the wind 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 rail material, and correct the rolling resistance coefficient according to the ambient humidity to obtain the accurate rolling resistance coefficient, and calculate the rolling resistance and air resistance based on 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 the 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 based on the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer. At the same time, the ambient 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;

[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] Furthermore, the logic for determining the running state of the train based on the running state parameters is as follows: the speed of the rail vehicle at time t is calibrated as V(t), the acceleration of the rail vehicle at time t is calibrated as a(t), and t is a time variable during the running process of the rail vehicle;

[0015] When V(t)-V(t-1)>0, and a(t)>0, it is judged that the rail vehicle is in an accelerated traction state;

[0016] When V(t)-V(t-1)<0, and a(t)<0, it is judged that the rail vehicle is in a deceleration braking state;

[0017] When V(t)-V(t-1)=0 and a(t)=0, it is judged that the rail vehicle is in a uniform speed driving state;

[0018] Among them, V(t-1) is the speed of the rail vehicle at the t-1th moment, that is, the speed of the rail vehicle at the moment before the t moment.

[0019] Furthermore, the wind direction drag coefficient is calculated based on the state parameters during operation and the width of the rail vehicle, wherein the logic for calculating the wind direction drag coefficient is:

[0020]

[0021] In the formula, C d (t) is the wind resistance coefficient at time t, Re(t) is the Reynolds number at time t, C d1 is the wind resistance coefficient corresponding to the Reynolds number Re(t) of 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 is:

[0022]

[0023] Where μ is the dynamic viscosity of air, ρ is the air density, and L is the width of the rail vehicle.

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

[0025] A1=W*0.2*D

[0026] Where 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;

[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, 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, E is the Young’s modulus of the track material;

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

[0031] C′ r (t) = C r *{1-h*(H(t)-H0)}

[0032] In the formula, C r ′ (t) is the precise rolling resistance coefficient at time t, h is the humidity influence coefficient, H(t) is the ambient humidity at time t, and H0 is the reference humidity.

[0033] Furthermore, the logic for calculating rolling resistance and air resistance based on the wind resistance coefficient and the precise rolling resistance coefficient is:

[0034] The air resistance is calculated based on the wind resistance coefficient and the windward area of ​​the rail vehicle. The specific formula is:

[0035]

[0036] In the formula, 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, V(t) is the speed of the rail vehicle at time t;

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

[0038] F roll (t) = C′ r (t)*M*g

[0039] In the formula, F roll (t) is the rolling resistance at time t, and g is the acceleration due to gravity.

[0040] Further, the instantaneous power of the rail vehicle is calculated based on the obtained rolling resistance and air resistance, and the logic 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 running speed of the rail vehicle, wherein the formula for calculating the force applied to drive the rail vehicle to move based on the obtained rolling resistance and air resistance is:

[0041] F tra (t)=M*a(t)+M*g*sinθ(t)+F drag (t)+F roll (t)

[0042] In the formula, F tra (t) is the force applied by the rail vehicle at time t, a(t) is the acceleration of the rail vehicle at time t, and θ(t) is the inclination slope of the rail vehicle at time t. When a(t) is greater than or equal to 0, F tra (t) represents the traction force, at this time F tra Its value is positive, the rail vehicle is accelerating or traveling at a constant speed. When a(t) is less than 0, F tra (t) represents the braking force, at this time F tra Its value is negative;

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

[0044] P tra (t) = F tra (t)*V(t)

[0045] Where P tra (t) is the instantaneous power of the rail vehicle at time t;

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

[0047]

[0048] In the formula, 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, where The formula is:

[0049]

[0050] In the formula, and are the maximum and minimum efficiencies of the rail vehicle traction motor under acceleration and deceleration, respectively, V ref 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, wherein the auxiliary energy consumption of the vehicle includes the energy consumed by air conditioning and lighting. The comprehensive energy consumption of the rail vehicle is:

[0052] E ve =E tra +e sta

[0053] In the formula, E ve is the comprehensive energy consumption of rail vehicles, E sta The auxiliary energy consumption of the vehicle.

[0054] Furthermore, the load current of the substation is calculated based on the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer. The formula for calculating the load current of the substation is:

[0055]

[0056] Where I(t) is the load current of the substation, and Y is the rated voltage of the transformer;

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

[0058] R′ r (t) = R r *{1+α*(Z(t)-Z ref )}

[0059] R′ x (t) = R x *{1+β*(Z(t)-Z ref )}

[0060] In the formula, R′ r (t) and R′ x (t) is the corrected winding resistance and line resistance of the transformer at time t, R r and R x are the calibrated winding resistance and calibrated line resistance of the transformer, α and β are the temperature coefficients of the winding resistance material and line resistance material, respectively. Z and Z ref They 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 line loss and load loss of the substation are calculated according to the formula:

[0062] P load (t)=I(t)*R′ r (t) 2

[0063] P loss (t)=I(t)*R′ x (t) 2

[0064] Where P load (t) and P loss (t) are the load loss and line loss of the substation at time t, respectively;

[0065] 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 network consumption is calculated in combination with the comprehensive energy consumption of the rail vehicle. The specific formula for calculating the transmission network consumption is:

[0066]

[0067] In the formula, e all Consumption for the transmission grid.

[0068] The present invention also provides a traction power supply simulation method for an urban rail vehicle, wherein the traction power supply simulation method for an urban rail vehicle is used to control the traction power supply simulation system of the urban rail vehicle described above, and the specific steps include:

[0069] Collecting characteristic parameters of urban rail vehicles and state parameters during operation, and judging the operation state of the train based on the state parameters during operation, wherein the characteristic parameters of urban rail vehicles include the mass of urban rail vehicles and the frontal area of ​​rail vehicles, and the state parameters during operation include the speed of rail vehicles, vehicle acceleration and the inclination gradient of tracks;

[0070] The wind resistance coefficient is calculated based on the state parameters during operation and the width of the rail vehicle. The rolling resistance coefficient is characterized based on the wheel-rail contact area and the Young's modulus of the rail material. The rolling resistance coefficient is corrected by the ambient humidity to obtain the precise rolling resistance coefficient. The rolling resistance and air resistance are calculated based on the wind resistance coefficient and the precise rolling resistance coefficient.

[0071] The instantaneous power of the rail vehicle is calculated based on the obtained rolling resistance and air resistance, and the efficiency adjustment factor is formulated according to the vehicle speed and acceleration at different times. The operating energy consumption of the rail vehicle is calculated by 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, the comprehensive energy consumption of the rail vehicle is calculated;

[0072] The load current of the substation is calculated based on the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer. At the same time, the ambient 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.

[0073] 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 network consumption is calculated in combination with the comprehensive energy consumption of the rail vehicle.

[0074] Compared with the prior art, the present invention has the following beneficial effects:

[0075] By collecting the characteristic parameters and state parameters of urban rail vehicles during operation, combined with dynamic environmental factors, a systematic traction power supply simulation method is constructed. Through accurate judgment and real-time monitoring of the vehicle's operating status, 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 operating efficiency of the rail transit system, but also significantly reduces energy consumption and operating costs. In addition, based on the comprehensive calculation of 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 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 of the grid load, and ultimately making urban rail transit more efficient, economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 It is a schematic diagram of the overall system structure of the present invention;

[0077] Figure 2 It is a schematic diagram of the overall method flow of the present invention. DETAILED DESCRIPTION

[0078] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0079] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0080] Example:

[0081] See also Figure 1 , the present invention provides a technical solution:

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

[0083] An operation parameter acquisition module is used to collect characteristic parameters of urban rail vehicles and state parameters during operation, and judge the operation state of the train based on the state parameters during operation, wherein the characteristic parameters of urban rail vehicles include the mass of urban rail vehicles and the frontal area of ​​rail vehicles, and the state parameters during operation include rail vehicle speed, vehicle acceleration and track inclination gradient;

[0084] The logic for judging the running state of the train based on the running state parameters is as follows: the speed of the rail vehicle at time t is calibrated as V(t), the acceleration of the rail vehicle at time t is calibrated as a(t), and t is the time variable in the running process of the rail vehicle;

[0085] When V(t)-V(t-1)>0, and a(t)>0, it is judged that the rail vehicle is in an accelerated traction state;

[0086] When V(t)-V(t-1)<0, and a(t)<0, it is judged that the rail vehicle is in a deceleration braking state;

[0087] When V(t)-V(t-1)=0 and a(t)=0, it is judged that the rail vehicle is in a uniform speed driving state;

[0088] Among them, V(t-1) is the speed of the rail vehicle at the time t-1, that is, the speed of the rail vehicle at the moment before time t. The collection interval between time t-1 and time t is generally greater than 0 and less than 0.5 seconds, and can be set according to actual needs. Among them, the quality of urban rail vehicles can be obtained by the manufacturer during the vehicle design and production stage. Usually, the vehicle quality data, including empty vehicle quality and fully loaded quality, can be found in the vehicle's technical manual or instruction manual.

[0089] The frontal area can be calculated from the vehicle's design drawings or CAD models, usually involving the vehicle's lateral and frontal projection areas. During the vehicle design phase, the vehicle's frontal area can be determined through wind tunnel testing.

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

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

[0092] The inclination of the track can be obtained through track sensors. Installing a tilt sensor or terrain sensor on the track can monitor the inclination of the track in real time and transmit the data to the operation control system. Using an inertial measurement unit (IMU) in combination with GPS can obtain track inclination information and improve data accuracy through multi-sensor fusion technology.

[0093] The instantaneous power calculation module is used to calculate the wind 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 rail material, and correct the rolling resistance coefficient according to the ambient humidity to obtain the accurate rolling resistance coefficient, and calculate the rolling resistance and air resistance based on the wind resistance coefficient and the accurate rolling resistance coefficient;

[0094] The wind direction drag coefficient is calculated based on the state parameters during operation and the width of the rail vehicle. The logic for calculating the wind direction drag coefficient is as follows:

[0095]

[0096] In the formula, C d (t) is the wind resistance coefficient at time t, Re(t) is the Reynolds number at time t, C d1 is the wind resistance coefficient corresponding to the Reynolds number Re(t) of 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 is:

[0097]

[0098] Where μ is the dynamic viscosity of air, usually around 1.81×10 -5 kg / (m·s), ρ is the air density, usually about 1.225kg / m 3 (under standard conditions at sea level), L is the width of the rail vehicle.

[0099] Reynolds Number is a very important dimensionless quantity in fluid dynamics, which is used to describe the influence of flow state (laminar or turbulent) on fluid motion and resistance. d (t) may vary with Reynolds number. The common empirical relationship is as follows: In laminar flow (usually Re(t) < 2000), C d (t) generally decreases with increasing Reynolds number.

[0100] In turbulent conditions (usually Re(t)>4000), C d (t) is a relatively constant value but varies slightly with Reynolds number until it reaches a stable value.

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

[0102] A1=W*0.2*D

[0103] 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 wheel width is the lateral dimension of the contact between the wheel and the track, 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, which is usually determined through experimental data or literature. This coefficient reflects the actual characteristics of the contact area between the wheel and the track under actual operating conditions. The contact between the wheel and the track is not a simple rectangle or circle, but a deformed contact area formed after force. The contact area will change due to pressure and the material properties of the wheel, and this coefficient is a summary of these effects. In actual tests, the actual contact area is calculated by measuring the rolling resistance under different conditions, and then the empirical coefficient is obtained.

[0104] The wheel width is usually obtained by the manufacturer's axle specification parameters or by measuring the actual vehicle. The wheel width of a standard rail vehicle may be within a certain range (for example, the common rail vehicle wheel width is generally between 0.15m and 0.25m). The wheel diameter is also usually obtained by the manufacturer's parameters or by actual measurement. The unit of wheel diameter is usually meters, and the common rail vehicle wheel diameter is generally between 0.6m and 1.2m, 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 track material is:

[0106]

[0107] In the formula, 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, E is the Young’s modulus of the track material;

[0108] The mass of the vehicle directly affects the normal force between the wheels and the track. The greater the normal force, the greater the friction, so the more massive the vehicle, the greater the rolling resistance. In the numerator, the mass M represents the weight of the vehicle, which is proportional to the friction that will be generated, which is one of the main factors in overcoming 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 track and is affected by the material, surface state and environmental conditions. In the numerator, the friction coefficient μ f Represents the friction associated with the movement of a vehicle, with higher coefficients of friction resulting in greater rolling resistance.

[0110] The contact area is the size of the area of ​​contact between the wheel and the track. The larger the contact area, the less pressure per unit area, so the overall friction may be reduced. In the denominator, an increase in the contact area A1 results in an increase in the rolling resistance coefficient C r This is because the increased contact area can disperse the normal force, thereby reducing the pressure per unit area and the corresponding friction.

[0111] Young's modulus is an indicator of the stiffness of a material, which indicates the material's ability to deform elastically under stress. The Young's modulus of the track material is closely related to the degree of deformation of the wheel after being subjected to stress. In the denominator, Young's modulus E affects rolling resistance by affecting the deformation of the track. A higher Young's modulus means that the material is more rigid and deforms less, so under the same load conditions, the rolling resistance coefficient will be relatively low.

[0112] The friction coefficient between the tire and the track is μ f The friction coefficient can be directly measured by experiment. A friction tester can be used to simulate the contact conditions between the tire and the track, record the friction force and normal force under different loads, and then calculate the friction coefficient μ f , or consult relevant research papers and technical reports to find friction coefficient data under similar conditions.

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

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

[0115] C′ r (t) = C r *{1-h*(H(t)-H0)}

[0116] In the formula, C′ r (t) is the precise rolling resistance coefficient at time t, h is the humidity influence coefficient, H(t) is the ambient humidity at time t, and H0 is the reference humidity.

[0117] In high humidity conditions, especially in rainy or humid environments, the contact surface between the tire and the rail may be covered with a water film. In this case, the water film reduces friction, resulting in a decrease in the friction coefficient and thus a decrease in the rolling resistance coefficient C. r The presence of water film can change the contact properties between the tire and the track, forming a fluid dynamic effect, which often leads to a reduction in friction.

[0118] The humidity influence coefficient h is set to represent the influence of humidity on the rolling resistance coefficient. The rolling resistance coefficient of the rail vehicle is measured by conducting field tests under different humidity conditions. 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, the range of the humidity influence coefficient is generally between 0 and 0.5 according to the experience accumulated by technicians in this field in long-term practical work.

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

[0120] The air resistance is calculated based on the wind resistance coefficient and the windward area of ​​the rail vehicle. The specific formula is:

[0121]

[0122] In the formula, 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, V(t) is the speed of the rail vehicle at time t;

[0123] The formula for calculating rolling resistance from the exact rolling resistance coefficient is:

[0124] F roll (t) = C′ r (t)*M*g

[0125] In the formula, F roll (t) is the rolling resistance at time t, and g 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 the 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;

[0127] The instantaneous power of the rail vehicle is calculated based on the obtained rolling resistance and air resistance, and the logic 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 running speed of the rail vehicle, wherein 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] F tra (t)=M*a(t)+M*g*sinθ(t)+F drag (t)+Froll (t)

[0129] In the formula, F tra (t) is the force applied by the rail vehicle at time t, a(t) is the acceleration of the rail vehicle at time t, and θ(t) is the inclination slope of the rail vehicle at time t. When a(t) is greater than or equal to 0, F tra (t) represents the traction force, at this time F tra Its value is positive, the rail vehicle is accelerating or traveling at a constant speed. When a(t) is less than 0, F tra (t) represents the braking force, at this time F tra Its value is negative;

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

[0131] P tra (t) = F tra (t)*V(t)

[0132] Where P tra (t) is the instantaneous power of the rail vehicle at time t;

[0133] The efficiency adjustment factor is formulated according to the vehicle speed and acceleration at different times. The formula for calculating the operating energy consumption of the rail vehicle through the vehicle's instantaneous power and efficiency adjustment factor is as follows:

[0134]

[0135] In the formula, 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, where The formula is:

[0136]

[0137] In the formula, and are the maximum and minimum efficiencies of the rail vehicle traction motor under acceleration and deceleration, respectively, V ref is the reference speed;

[0138] The reference speed V ref It can be set according to actual needs, with a rough range of 30km / h to 200km / h.

[0139] In the uniform speed state, the acceleration of the train is close to zero, which means that the train is running at a stable speed. In this case, the energy utilization efficiency is higher, so the efficiency adjustment factor is set as:

[0140] Under acceleration, the train needs to overcome more resistance (such as air resistance, rolling resistance, etc.), and the efficiency of the traction system is usually reduced. To describe this phenomenon, the efficiency adjustment factor is: is an exponential decay function, as the speed decreases with the reference speed V ref The efficiency decreases nonlinearly with the deviation from the reference speed. When the train speed is far away from the reference speed, the energy loss increases rapidly, resulting in a decrease in efficiency. This setting reflects the nonlinear characteristics in practice: when accelerating at high speed, the efficiency of the motor and other systems may drop significantly.

[0141] In the deceleration state, the train uses braking to reduce speed. The energy loss is similar to acceleration, but the efficiency is usually lower because not all energy can be effectively fed back during braking. In particular, when using mechanical brakes, energy cannot be fully fed back to the grid. For example, air brakes and friction brakes cause energy to be lost in the form of heat. In this case, the efficiency adjustment factor is set to: The attenuation function is the same as that during acceleration, indicating that the energy loss during deceleration is also related to the degree to which the speed deviates 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, speed, etc.) and output power (such as mechanical power, kinetic energy, etc.). Use 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%, limited by their thermal efficiency.

[0143] Minimum efficiency under deceleration, minimum efficiency usually indicates 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%, depending on the design and material properties of the braking system. For mechanical braking systems, the minimum efficiency may be 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 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, wherein the auxiliary energy consumption of the vehicle includes the energy consumed by air conditioning and lighting. The comprehensive energy consumption of the rail vehicle is:

[0145] E ve =E tra +Esta

[0146] In the formula, E ve is the comprehensive energy consumption of rail vehicles, E sta The auxiliary energy consumption of the vehicle.

[0147] Among them, the auxiliary energy consumption of the vehicle is E sta It is expressed as the sum of the energy consumption of the air conditioning system and the lighting energy consumption, where the energy consumption of the air conditioning system is calculated by combining the basic energy consumption of the air conditioning system and the additional energy consumption caused by the increase in the number of passengers, combined with the number of passengers;

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

[0149] The substation loss characterization module is used to calculate the load current of the substation based on the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer. At the same time, the ambient 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;

[0150] The load current of the substation is calculated based on the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer. The formula for calculating the load current of the substation is:

[0151]

[0152] In the formula, I(t) is the load current of the substation at time t, and Y is the rated voltage of the transformer;

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

[0154] R′ r (t) = R r *{1+α*(Z(t)-Z ref )}

[0155] R′ x (t) = R x *{1+β*(Z(t)-Z ref )}

[0156] In the formula, R′ r (t) and R′ x (t) is the corrected winding resistance and line resistance of the transformer at time t, R r and R x are the calibrated winding resistance and calibrated line resistance of the transformer, α and β are the temperature coefficients of the winding resistance material and line resistance material, respectively. Z and Z refThey are the current ambient temperature and the standard reference temperature respectively;

[0157] The reference standard temperature is usually 20℃ or 25℃. The temperature coefficient of winding resistance α and the temperature coefficient of line resistance β indicate the sensitivity of the material's resistance to temperature changes. Generally, metal materials (such as copper and aluminum) have positive temperature coefficients. Transformer windings are usually made of metals with good electrical conductivity (such as copper or aluminum), and their temperature coefficients are usually between 0.00393 / ℃ (copper) and 0.0039 / ℃ (aluminum). The line resistance also increases with increasing temperature and has a similar temperature coefficient.

[0158] 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 according to the formula:

[0159] P load (t)=I(t)*R′ r (t) 2

[0160] P loss (t)=I(t)*R′ x (t) 2

[0161] Where P load (t) and P loss (t) are the load loss and line loss of the substation at time t, respectively;

[0162] 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.

[0163] 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 network consumption is calculated in combination with the comprehensive energy consumption of the rail vehicle. The specific formula for calculating the transmission network consumption is:

[0164]

[0165] In the formula, e all Consumption for the transmission grid.

[0166] See also Figure 2 The present invention also provides a traction power supply simulation method for an urban rail vehicle, wherein the traction power supply simulation method for an urban rail vehicle is used to control the traction power supply simulation system of the urban rail vehicle, and the specific steps include:

[0167] Step 1: Collect characteristic parameters of urban rail vehicles and state parameters during operation, and judge the operation state of the train based on the state parameters during operation, wherein the characteristic parameters of urban rail vehicles include the mass of urban rail vehicles and the frontal area of ​​rail vehicles, and the state parameters during operation include the speed of rail vehicles, vehicle acceleration and the inclination gradient of tracks;

[0168] Step 2: 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 by the ambient humidity to obtain the precise rolling resistance coefficient. Calculate the rolling resistance and air resistance based on the wind resistance coefficient and the precise rolling resistance coefficient.

[0169] Step 3: Calculate the instantaneous power of the rail vehicle based on the obtained rolling resistance and air resistance, formulate the 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;

[0170] Step 4: Calculate the load current of the substation based on the comprehensive energy consumption of the rail vehicle and 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. Based on the obtained load current and the corrected winding resistance and line resistance, calculate the line loss and load loss of the substation.

[0171] Step 5: 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 transmission network consumption in combination with the comprehensive energy consumption of the rail vehicle.

[0172] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0173] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed 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, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0175] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A traction power supply simulation system for urban rail vehicles, characterized in that: Specifically include: An operation parameter acquisition module is used to collect characteristic parameters of urban rail vehicles and state parameters during operation, and judge the operation state of the train based on the state parameters during operation, wherein the characteristic parameters of urban rail vehicles include the mass of urban rail vehicles and the frontal area of ​​rail vehicles, and the state parameters during operation include rail vehicle speed, vehicle acceleration and track inclination gradient; The instantaneous power calculation module is used to calculate the wind 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 rail material, and correct the rolling resistance coefficient according to the ambient humidity to obtain the accurate rolling resistance coefficient, and calculate the rolling resistance and air resistance based on the wind resistance coefficient and the accurate rolling resistance coefficient; 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 the 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; The substation loss characterization module is used to calculate the load current of the substation based on the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer. At the same time, the ambient 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 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.

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

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

4. The traction power supply simulation system for urban rail vehicles according to claim 1, characterized in that: The rolling resistance coefficient is characterized based on the wheel-rail contact area and the Young's modulus of the rail material, and the rolling resistance coefficient is corrected by the ambient humidity. The specific logic is: the wheel-rail contact area is calculated by 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 Where 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: In the formula, 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, E is the Young’s modulus of the track material; The rolling resistance coefficient is corrected by the ambient humidity to obtain the precise rolling resistance coefficient. The specific formula for calculating the precise rolling resistance coefficient is: C′ r (t)=C r *{1-h*(H(t)-H0)} In the formula, C′ r (t) is the precise rolling resistance coefficient at time t, h is the humidity influence coefficient, H(t) is the ambient humidity at time t, and H0 is the reference humidity.

5. The traction power supply simulation system for urban rail vehicles according to claim 4, characterized in that: The logic for calculating rolling resistance and air resistance based on the wind resistance coefficient and the precise rolling resistance coefficient is: The air resistance is calculated based on the wind resistance coefficient and the windward area of ​​the rail vehicle. The specific formula is: In the formula, 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, V(t) is the speed of the rail vehicle at time t; The formula for calculating rolling resistance from the exact rolling resistance coefficient is: F roll (t)=C′ r (t)*M*g In the formula, F roll (t) is the rolling resistance at time t, and g is the acceleration due to gravity.

6. The traction power supply simulation system for urban rail vehicles according to claim 5, characterized in that: The instantaneous power of the rail vehicle is calculated based on the obtained rolling resistance and air resistance, and the logic 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 running speed of the rail vehicle, wherein the formula for calculating the force applied to drive the rail vehicle to move based on the obtained rolling resistance and air resistance is: F tra (t)=M*a(t)+M*g*sinθ(t)+F drag (t)+F roll (t) In the formula, F tra (t) is the force exerted by the rail vehicle at time t, a(t) is the acceleration of the rail vehicle at time t, and θ(t) is the inclination slope of the rail vehicle at time t. When a(t) is greater than or equal to 0, F tra (t) represents the traction force, at this time F tra Its value is positive, the rail vehicle is accelerating or traveling at a constant speed. When a(t) is less than 0, F tra (t) represents the braking force, at this time F tra Its value is negative; The formula for determining the instantaneous power of a rail vehicle based on the force exerted by the motion and the 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 efficiency adjustment factor is formulated according to the vehicle speed and acceleration at different times. The formula for calculating the operating energy consumption of the rail vehicle through the vehicle's instantaneous power and efficiency adjustment factor is as follows: In the formula, 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, where The formula is: In the formula, and are the maximum and minimum efficiencies of the rail vehicle traction motor under acceleration and deceleration, respectively, 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, wherein the auxiliary energy consumption of the vehicle includes the energy consumed by air conditioning and lighting. The comprehensive energy consumption of the rail vehicle is: AND ve =And tra +e sta In the formula, E ve is the comprehensive energy consumption of rail vehicles, E sta The auxiliary energy consumption of the vehicle.

7. The traction power supply simulation system for urban rail vehicles according to claim 6, characterized in that: The load current of the substation is calculated based on the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer. The formula for calculating the load current of the substation is: Where I(t) is the load current of the substation, and Y is the rated voltage of the transformer; The ambient temperature data is collected to correct the winding resistance and line resistance of the substation transformer. The specific formula is: R′ r (t)=R r *{1+α*(Z(t)-Z ref )} R′ x (t)=R x *{1+β*(Z(t)-Z ref )} In the formula, R′ r (t) and R′ x (t) are the corrected winding resistance and line resistance of the transformer at time t, R r and R x are the calibrated winding resistance and calibrated line resistance of the transformer, α and β are the temperature coefficients of the winding resistance material and line resistance material, Z(t) and Z ref They are the current ambient temperature and the standard reference temperature respectively; 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 according to the formula: P load (t)=I(t)*R′ r (t) 2 P loss (t)=I(t)*R′ x (t) 2 Where P load (t) and P loss (t) are the load loss and line loss of the substation at time t, 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 network consumption is calculated in combination with the comprehensive energy consumption of the rail vehicle. The specific formula for calculating the transmission network consumption is: In the formula, E all Consumption for the transmission grid.

8. A traction power supply simulation method for urban rail vehicles, characterized in that: The traction power supply simulation method for an urban rail vehicle is used to control the traction power supply simulation system for an urban rail vehicle according to any one of claims 1 to 7, and the specific steps include: Collecting characteristic parameters of urban rail vehicles and state parameters during operation, and judging the operation state of the train based on the state parameters during operation, wherein the characteristic parameters of urban rail vehicles include the mass of urban rail vehicles and the frontal area of ​​rail vehicles, and the state parameters during operation include the speed of rail vehicles, vehicle acceleration and the inclination gradient of tracks; The wind resistance coefficient is calculated based on the state parameters during operation and the width of the rail vehicle. The rolling resistance coefficient is characterized based on the wheel-rail contact area and the Young's modulus of the rail material. The rolling resistance coefficient is corrected by the ambient humidity to obtain the precise rolling resistance coefficient. The rolling resistance and air resistance are calculated based on the wind resistance coefficient and the precise rolling resistance coefficient. The instantaneous power of the rail vehicle is calculated based on the obtained rolling resistance and air resistance, and the efficiency adjustment factor is formulated according to the vehicle speed and acceleration at different times. The operating energy consumption of the rail vehicle is calculated by 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, the comprehensive energy consumption of the rail vehicle is calculated; The load current of the substation is calculated based on the comprehensive energy consumption of the rail vehicle and the rated voltage of the substation transformer. At the same time, the ambient 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. 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 network consumption is calculated in combination with the comprehensive energy consumption of the rail vehicle.

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