Train traction power supply control method and system and electronic equipment

Abstract

The invention discloses a control method and system for traction power supply of a train and electronic equipment. The control method comprises the steps that the running power, a first circuit parameter, a second circuit parameter and a third circuit parameter of the train are obtained; determining the state of charge of the vehicle-mounted battery based on the second circuit parameter, and obtaining first output power and second output power through a preset fuzzy logic model; determining a negative sequence current according to the second circuit parameter and the third circuit parameter; based on the negative-sequence current and a preset standard negative-sequence current, determining respective compensation current of the ground energy storage system and the vehicle-mounted battery in any working state so as to offset the negative-sequence current generated by the traction contact network; and the traction contact net performs traction power supply on the train with the first output power and the vehicle-mounted battery with the second output power. The system and the electronic equipment are used for executing the traction power supply control method of the train. Through the arrangement, the stability of train power supply and the energy efficiency during train operation can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of railway energy supply management, and particularly relates to a control method and system for traction power supply of a train. BACKGROUND

[0002] In the process of running of an existing train, a control system for traction power supply of an electrified railway is established based on a high-voltage power grid to provide power support for train running, so that the train running is highly dependent on the power supply of a traction catenary. However, the train driven by electric power can be regarded as a single-phase load with high power, asymmetry and pulse characteristics. When the traction catenary supplies power to the train, the traction load fluctuation caused by the train will cause three-phase imbalance of the traction catenary, thereby resulting in negative sequence current in the traction catenary, which will affect the stability of the power supply of the traction catenary.

[0003] Meanwhile, the existing train mostly relies on the power supply of the traction catenary. In order to enable the traction catenary to stably support the running of the train, a traction transformer with a large volume is usually arranged to enable the traction catenary to adapt to the power supply demand of the train running. However, the traction transformer with a large volume will increase the energy consumption of the train, thereby affecting the energy efficiency of the train running. SUMMARY

[0004] In order to solve the problems in the prior art, the present application aims to provide a control method and system for traction power supply of a train and an electronic device, which can improve the stability of power supply to the train and the energy efficiency during the running of the train.

[0005] To achieve the above object, the present application adopts the following technical solutions: In a first aspect, the present application provides a control method for traction power supply of a train, comprising: obtaining a running power of the train, a first circuit parameter of a traction catenary, a second circuit parameter of an on-board battery, and a third circuit parameter of a ground energy storage system, wherein any circuit parameter comprises resistance, voltage and current; determining a state of charge of the on-board battery based on the second circuit parameter, and inputting the state of charge, the first circuit parameter and the running power of the train into a preset fuzzy logic model to obtain a first output power of the traction catenary and a second output power of the on-board battery; determining a negative sequence current generated by the traction catenary according to the second circuit parameter of the on-board battery and the third circuit parameter of the ground energy storage system in different working states, wherein the working states include a standby state, a discharging state and a charging state; determining respective compensation currents of the ground energy storage system and the on-board battery in any working state based on the negative sequence current and a preset standard negative sequence current; the traction catenary supplies power to the train at the first output power, the on-board battery supplies power to the train at the second output power, and the ground energy storage system and the on-board battery offset the negative sequence current generated by the traction catenary with the respective compensation currents.

[0006] Further, the SOC of the on-board battery is determined based on the second circuit parameter, including: obtaining the open circuit voltage, the output voltage and the internal resistance of the on-board battery to determine the internal current of the on-board battery; obtaining the discharge time of the on-board battery, and determining the maximum value of the battery capacity of the on-board battery according to the product of the internal current and the discharge time of the on-board battery; and obtaining the SOC of the on-board battery based on the maximum value of the battery capacity and the discharge time of the on-board battery.

[0007] Further, the first output power of the traction catenary is obtained, including: determining a first membership function corresponding to the running power of the train and a second membership function corresponding to the SOC of the on-board battery; obtaining a first fuzzy subset of the first membership function and a second fuzzy subset of the second membership function, and obtaining a third membership function according to the corresponding relationship between the first fuzzy subset and the second fuzzy subset; and performing defuzzification on the third membership function based on the weighted average method to obtain a first proportion factor and a first barycenter value, and obtaining the product of the first barycenter value and the first proportion factor to obtain the first output power.

[0008] Further, the second output power of the traction catenary is obtained, including: obtaining the difference between the running power of the train and the first output power to obtain the residual running power of the train; substituting the residual running power of the train and the SOC of the on-board battery into the membership function to obtain a fourth membership function corresponding to the residual running power of the train; obtaining a third fuzzy subset of the fourth membership function, and obtaining a fifth membership function according to the corresponding relationship between the second fuzzy subset and the third fuzzy subset; and performing defuzzification on the fifth membership function based on the weighted average method to obtain a second proportion factor and a second barycenter value, and obtaining the product of the second barycenter value and the second proportion factor to obtain the second output power.

[0009] Further, the standard negative sequence current includes a preset probability negative sequence current and a maximum probability negative sequence current, and the compensation currents of the ground energy storage system and the on-board battery in any working state are determined, including: obtaining a first probability corresponding to the preset probability negative sequence current and a second probability, the second probability being the standard probability of the preset probability negative sequence current; obtaining a first maximum probability corresponding to the maximum probability negative sequence current and a second maximum probability, the second maximum probability being the standard probability of the maximum probability negative sequence current; obtaining the active component and the reactive component of the preset probability current, the maximum probability current and the running power; comparing the first probability and the second probability, and comparing the first maximum probability and the second maximum probability, and determining the compensation current based on the negative sequence current, the preset probability negative sequence current, the maximum probability negative sequence current, the preset probability current, the maximum probability current, the active component and the reactive component of the running power.

[0010] Further, based on the negative sequence current and the preset standard negative sequence current, the respective compensation currents of the ground energy storage system and the on-board battery in any working state are determined, including: obtaining the ratio of the input voltage of the traction substation to the voltage of the traction catenary of the on-board battery and the ground energy storage system in different working states; obtaining the product of the running power of the train, the first circuit parameter of the traction catenary, the ratio of the input voltage of the traction substation to the voltage of the traction catenary and the constant, to determine the negative sequence current; comparing the first probability and the second probability, and comparing the first maximum probability and the second maximum probability, and based on the corresponding negative sequence currents of the on-board battery and the ground energy storage system in different working states, the preset probability negative sequence current, the maximum probability negative sequence current, the preset probability current, the maximum probability current, the active component and the reactive component of the running power, to determine the compensation currents of the on-board battery and the ground energy storage system in different working states.

[0011] Further, the respective compensation currents of the ground energy storage system and the on-board battery in any working state are determined, when the first probability is greater than the second probability, and the first maximum probability is greater than the second maximum probability, and the preset probability negative sequence current is greater than the preset probability current, and the maximum probability negative sequence current is greater than the maximum probability current, and the calculation formula of the compensation current is as follows: ; When the first probability is greater than the second probability, and the first maximum probability is not greater than the second maximum probability, and the preset probability negative sequence current is greater than the preset probability current, and the maximum probability negative sequence current is less than the maximum probability current, the calculation formula of the compensation current is as follows: ; When the first probability is not greater than the second probability, and the first maximum probability is greater than the second maximum probability, and the preset probability negative sequence current is less than the preset probability current, and the maximum probability negative sequence current is greater than the maximum probability current, the calculation formula of the compensation current is as follows: ; Wherein, is the ratio of the input voltage of the traction substation to the voltage of the traction catenary, is the active component of the running power, is the compensation current, is the reactive component of the running power, is the preset probability current, is the negative sequence current, is the preset probability negative sequence current, is the maximum probability current.

[0012] In a second aspect, the embodiments of the present application provide a control system for traction power supply of a train for driving the train to run, comprising a power supply device and a central control device, the power supply device is configured to supply electric energy, and comprises a traction catenary, an on-board battery and a ground energy storage system, and the central control device is electrically connected with the power supply device, and the central control device executes the control method for traction power supply of a train when receiving the electric energy output by the power supply device.

[0013] Further, the on-board battery comprises a serial battery link, a battery fuse contactor and a fuse switch, the serial battery link comprises a plurality of battery modules connected in series, adjacent serial battery links are connected in parallel; the battery fuse contactor is configured to cut off the circuit connection between the on-board battery and the train, and the battery fuse contactor is electrically connected with one end of the serial battery link; the battery fuse contactor is configured to cut off the circuit connection inside the on-board battery, and the battery fuse contactor is electrically connected with both ends of the serial battery link; and the fuse switch is configured to electrically isolate adjacent battery modules in the serial battery link, and the fuse switch is arranged between adjacent two battery modules.

[0014] In a third aspect, the embodiments of the present application provide an electronic device, comprising a memory and a processor, the memory stores a computer program, and the processor is configured to run the computer program to execute the control method for traction power supply of a train.

[0015] The control method for traction power supply of a train can distribute the output power of the on-board battery and the traction catenary to the train through the fuzzy logic model, so as to reduce the dependence of the train on the traction catenary for power supply, thereby the output power of the traction catenary does not need to meet the peak power of the train running, which is conducive to reducing the volume of the traction transformer, and further can avoid the overlarge volume of the traction transformer to cause the energy consumption of the train running, thereby improving the energy efficiency of the train running. Meanwhile, the ground energy storage system and the on-board battery can provide compensation current to offset the negative sequence current in the traction catenary, thereby improving the stability of the traction catenary power supply. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 FIG. 1 is a hardware structure block diagram of an electronic device according to an embodiment of the present application.

[0017] Figure 2 FIG. 2 is a flowchart of a control method for traction power supply of a train according to an embodiment of the present application.

[0018] Figure 3 FIG. 3 is a specific flowchart of step S2 according to an embodiment of the present application.

[0019] Figure 4 FIG. 4 is a function diagram of a first membership function according to an embodiment of the present application.

[0020] Figure 5 FIG. 5 is a function diagram of a second membership function according to an embodiment of the present application.

[0021] Figure 6 Function graph of the third membership function of the embodiment of the present application.

[0022] Figure 7 Function graph of the fourth membership function of the embodiment of the present application.

[0023] Figure 8 Function graph of the fifth membership function of the embodiment of the present application.

[0024] Figure 9 Specific flow chart of step S4 of the embodiment of the present application.

[0025] Figure 10 Flow chart of determining the compensation current of the embodiment of the present application.

[0026] Figure 11 Structure block diagram of the control system of the traction power supply of the train of the embodiment of the present application.

[0027] Figure 12 Circuit diagram of the on-board battery of the embodiment of the present application. DETAILED DESCRIPTION

[0028] The present application will be described in detail below with reference to the specific embodiments shown in the drawings, but these embodiments do not limit the present application, and the structural, method, or functional changes made by those skilled in the art based on these embodiments are included in the protection scope of the present application.

[0029] The control method of the traction power supply of the train provided in the embodiment can be executed in an electronic device 100 or similar device. Figure 1 is a hardware structure block diagram of an electronic device 100 executing the embodiment of the present application. As shown in Figure 1 , the electronic device 100 can include one or more (only one is shown in the figure) memories 12 and processors 11, and the electronic device 100 is a control terminal of a train system, which is used to control the operation of each train section in the train system, and according to the running requirements of the train, the output power of the traction catenary and the on-board battery described below is allocated, so that the train can run, and the energy consumption of the train during running is reduced. Figure 1

[0030] Among them, the memory 12 stores program instructions, for example, software programs and modules of application software, such as a computer program of a control method of the traction power supply of a train in the embodiment. The processor 11 is used to execute the program instructions stored in the memory 12, and by running the computer program stored in the memory 12, various functional applications and data processing can be executed, that is, the traction power supply of the train by the traction catenary and the on-board battery is realized.

[0031] ​The processor 11 can include, but is not limited to, a microcontroller unit (MCU) or a field programmable gate array (FPGA) or the like.

[0032] Those skilled in the art can understand that, Figure 1 The structure shown is only schematic, and does not limit the structure of the electronic device 100 described above. For example, the electronic device 100 can also include more or fewer components than Figure 1 shown, or have a different configuration from Figure 1 shown.

[0033] In some embodiments, part of the control method of the traction power supply of the train is executed in the electronic device 100, and the remaining part of the control method of the traction power supply of the train is executed on the train to achieve the distribution of the output power of the overhead contact system and the on-board battery and to offset the negative sequence current in the overhead contact system.

[0034] The embodiment also provides a control method of a traction power supply of a train, Figure 2 is a flowchart of a control method of a traction power supply of a train according to an embodiment of the present application, which is used to improve the stability of the power supply to the train and the energy efficiency when the train is running.

[0035] As Figure 2 shown, in the embodiments provided by the present application, the control method of the traction power supply of the train includes the following steps: Step S1: obtaining the running power of the train, the first circuit parameters of the overhead contact system, the second circuit parameters of the on-board battery, and the third circuit parameters of the ground energy storage system. Any circuit parameter includes the resistance of the circuit, the voltage applied to the circuit, and the current flowing through the circuit. The above settings can facilitate the subsequent acquisition of the compensation current and the subsequent distribution of the power supply power of the on-board battery and the overhead contact system by obtaining the running power of the train and the circuit parameters.

[0036] Step S2: determining the state of charge of the on-board battery based on the second circuit parameters, and inputting the state of charge, the first circuit parameters and the running power of the train into a preset fuzzy logic model to obtain the first output power of the overhead contact system and the second output power of the on-board battery.

[0037] A fuzzy logic model is a mathematical framework that mimics human thinking and decision-making. It is used to process precise input data into outputs that conform to human intuition through experience-based fuzzy rules. In this application, fuzzy rules are used to process the state of charge of the onboard battery, the first circuit parameters, and the train's operating power to allocate the output power of the onboard battery and the traction contact network. This can reduce the train's dependence on the traction contact network for power supply, so that the traction contact network does not need to meet the peak power requirements of the train's operation. This can reduce the size of the traction transformer, thereby reducing the energy consumption of the train carrying the traction transformer during operation and improving the energy efficiency of the train.

[0038] like Figure 3 As shown, in some embodiments, step S2, which involves determining the state of charge of the vehicle battery based on the second circuit parameters, includes: Step S21: Obtain the open-circuit voltage, output voltage, and internal resistance of the vehicle battery to determine the internal current of the vehicle battery. The formula for determining the internal current is as follows: ; in, This refers to the internal current of the vehicle battery. This refers to the open-circuit voltage of the vehicle battery. This refers to the output voltage of the vehicle battery. The internal resistance of the vehicle battery is given. The internal current of the vehicle battery can be calculated using the formula for internal current described above. In some embodiments, the open-circuit voltage, output voltage, and internal resistance of the vehicle battery can be obtained through the RINT equivalent circuit model to determine the internal current of the vehicle battery; this application does not impose any limitations on this.

[0039] In this embodiment, by determining the internal current This will facilitate the subsequent determination of the vehicle's battery capacity.

[0040] Step S22: Obtain the discharge time of the vehicle battery, and determine the maximum battery capacity of the vehicle battery based on the product of the internal current of the vehicle battery and the discharge time.

[0041] The formula for determining the battery capacity of the aforementioned vehicle battery is as follows: ; in, This refers to the battery capacity of the vehicle's onboard battery. It is a constant. The discharge time of the vehicle battery is used as the starting point. The battery capacity can be calculated under different time conditions using the formula described above. Then, the battery capacity with the largest value among the calculation results is obtained, thus determining the maximum battery capacity of the vehicle battery.

[0042] In the embodiment, the state of charge is a ratio between the remaining power in the on-board battery and the rated capacity, and determining the state of charge of the on-board battery facilitates real-time battery capacity of the on-board battery.

[0043] Step S23: obtaining the state of charge of the on-board battery based on the maximum value of the battery capacity and the discharge time of the on-board battery.

[0044] The formula for determining the state of charge of the on-board battery is as follows: ; wherein, is the state of charge of the on-board battery at the next time, is the state of charge of the on-board battery at the current time, is the maximum value of the battery capacity of the on-board battery. That is, the state of charge of the on-board battery at different times can be calculated by the above formula for determining the state of charge of the on-board battery.

[0045] In the embodiment, by obtaining the state of charge of the on-board battery, it is beneficial to subsequently control the on-board battery to output corresponding power for power supply according to the state of charge of the on-board battery and the power demand of the train during operation.

[0046] As shown in FIG. 2, the step of obtaining the first output power of the traction catenary in step S2 includes: Figure 3 Step S24: determining a first membership function corresponding to the running power of the train and a second membership function corresponding to the state of charge of the on-board battery. The membership function is a function for describing the membership degree of an element to a certain fuzzy set. The membership function can map the input element to a value in the range of [0, 1] to facilitate the degree of the input element belonging to the fuzzy set.

[0047] The above setting can fuzz the running power of the train according to the fuzzy rule through the first membership function, and can fuzz the state of charge of the on-board battery according to the fuzzy rule through the second membership function, so as to reduce the influence of the change of the running power of the train and the state of charge of the on-board battery on the accuracy of determining the first output power, thereby reducing the dependence on the accuracy of the running power of the train and the state of charge of the on-board battery, and improving the robustness of subsequently obtaining the first output power. In the present application, the first membership function and the second membership function adopt Gaussian membership function and generalized bell-shaped membership function as input membership functions, and the Gaussian membership function is: ; The generalized bell-shaped membership function is: ; wherein, ,​ , , All are constants. As the input quantity, the train's operating power is input in the first membership function to obtain, for example... Figure 4 The diagram shows the fuzzy subset graph of the first membership function, which is the membership function of the train's operating power. Figure 4 The horizontal and vertical axes represent the membership degree of different train operating power, ranging from -1.0 to 1.0. The input in the second membership function is the state of charge of the onboard battery. This is used to obtain... Figure 5 The second membership function, shown in the fuzzy subset graph, represents the membership function of the vehicle battery's state of charge. Figure 5 The horizontal and vertical axes represent the degree of membership of different states of charge of the vehicle battery, with the membership range including [-1.0, 1.0].

[0048] Step S25: Obtain the first fuzzy subset of the first membership function and the second fuzzy subset of the second membership function, and obtain the third membership function according to the correspondence between the first fuzzy subset and the second fuzzy subset. In the above settings, the third membership function is the result function after the fuzzy rule processing of the first output power, which is beneficial for obtaining the first output power in the future, thereby facilitating the subsequent allocation of the output power of the on-board battery and traction contact network to power the train. In this application, the first fuzzy subset is {NH, NM, NL, PL, PM, PH}, the second fuzzy subset is {VL, L, M, H, VH}, and the third membership function is obtained using triangular membership function and trapezoidal membership function, wherein the triangular membership function is: ; The trapezoidal membership function is: ; The third membership function, obtained through the triangular and trapezoidal membership functions, is used to obtain, for example... Figure 6 The fuzzy subset graph of the third membership function is shown, which is the membership function of the first output power. Figure 5 The horizontal and vertical axes represent the membership degrees of different first output powers, ranging from -1.0 to 1.0. The fuzzy subset of the third membership function is {P0, P1, P2, P3, P4, P5}. The correspondence (i.e., fuzzy rules) between the first, second, and third fuzzy subsets is shown in the table below:

[0049] in, The power of the traction overhead contact line is [value], and the train's operating power is [value]. That is, the fuzzy subset of the third membership function can be determined through the first fuzzy subset, the second fuzzy subset and the fuzzy rules in the above table, so that the third membership function can be determined through defuzzification subsequently, to facilitate subsequent acquisition of the first output power.

[0050] Step S26: Defuzzification of the third membership function based on the weighted average method to obtain the first scale factor and the first barycenter value, and to obtain the product of the first barycenter value and the first scale factor to obtain the first output power.

[0051] In the present application, the preset running power threshold range of the train is [0, ], is the maximum value of the running power of the train. In the above setting, the preset is any point of the first output power in the output range, then the point has a corresponding membership value in the third membership function. The expression for calculating the first barycenter value is as follows: ; wherein, is the first barycenter value, that is, the first barycenter value can be determined by calculating the expression of the first barycenter value. The expression for calculating the first scale factor is as follows: ; wherein, is the first scale factor, that is, the first scale factor can be determined by calculating the expression of the first scale factor. The product of the first barycenter value and the first scale factor is calculated to determine the first output power, and the expression for calculating the first output power is as follows: ; wherein is the first output power, that is, the first output power can be determined by calculating the expression of the first output power. As an embodiment, the step of obtaining the second output power of the on-board battery in step S2 comprises: Step S27: Obtaining the difference between the running power of the train and the first output power to obtain the remaining running power of the train. The formula for calculating the remaining running power of the train is as follows: ; wherein, is the remaining running power of the train, that is, the remaining running power of the train can be calculated through the above formula for calculating the remaining running power of the train.

[0052] Step S28: Substituting the remaining running power of the train and the state of charge of the on-board battery into the membership function to obtain a fourth membership function corresponding to the remaining running power of the train; obtaining a third fuzzy subset of the fourth membership function, and obtaining a fifth membership function according to the corresponding relationship between the second fuzzy subset and the third fuzzy subset.

[0053] As set forth above, the fourth membership function can be used to fuzz the remaining running power of the train according to the fuzzy rule, so as to reduce the influence of the change of the remaining running power of the train on the accuracy of determining the second output power, thereby reducing the dependence on the accuracy of the remaining running power of the train, and further improving the robustness of subsequently obtaining the second output power.

[0054] In the present application, the fourth membership function can be obtained by processing the Gaussian membership function and the generalized bell-shaped membership function, and is used as an input membership function to obtain a fuzzy subset graph of the fourth membership function as shown in Figure 7 , i.e., a membership degree function of the remaining running power of the train. In Figure 7 , the abscissa and the ordinate represent the membership degrees of different remaining running powers of the train, and the range of the membership degrees includes [-1.0, 1.0]. The fifth membership function can be obtained by processing the triangular membership function and the trapezoidal membership function, and is used as an output membership function to obtain a fuzzy subset graph of the fifth membership function as shown in Figure 8 , i.e., a membership degree function of the second output power. In Figure 8 , the abscissa and the ordinate represent the membership degrees of different second output powers, and the range of the membership degrees includes [-1.0, 1.0]. In addition, the third fuzzy subset is {NH, NM, NL, PL, PM, PH}, the fuzzy subset of the fifth membership function is {NH, NM, NL, Z, PL, PM, PH}, and the corresponding relationship (i.e., the fuzzy rule) between the second fuzzy subset, the third fuzzy subset and the fuzzy subset of the fifth membership function is shown in the following table:

[0055] That is, the fuzzy subset of the fifth membership function can be determined by the second fuzzy subset, the third fuzzy subset and the fuzzy rule in the above table, so that the required fifth membership function can be determined to facilitate subsequent obtaining of the second output power.

[0056] Step S29: Defuzzifying the fifth membership function based on the weighted average method to obtain a second proportional factor and a second barycenter value, and obtaining the product of the second barycenter value and the second proportional factor to obtain the second output power.

[0057] In the present application, the threshold range of the second output power of the preset on-board battery is [0, ], is the maximum value of the second output power of the on-board battery. In the above setting, the maximum value of the second output power of the on-board battery is preset is any point in the output range of the second output power, then the point has a corresponding membership value in the fifth membership function The expression for calculating the second gravity value is as follows: ; wherein, is the second gravity value, that is, the second gravity value can be determined by calculating the expression of the second gravity value. The expression for calculating the second proportion factor is as follows: ; wherein, is the second proportion factor, that is, the second proportion factor can be determined by calculating the expression of the second proportion factor. The product of the second gravity value and the second proportion factor is calculated to determine the second output power, and the expression for calculating the first output power is as follows: ; wherein is the first output power, that is, the second output power of the on-board battery can be determined by calculating the expression of the second output power.

[0058] For example, the first output power and the second output power can be obtained by a fuzzy logic controller, and the fuzzy logic controller for obtaining the first output power is defined as a first fuzzy logic controller, and the fuzzy logic controller for obtaining the second output power is defined as a second fuzzy logic controller. The state of charge of the on-board battery and the running power of the train are input into the first fuzzy logic controller, so that the first output power of the traction catenary can be obtained.

[0059] Since the negative sequence current needs to be offset by the on-board battery during the process of the traction catenary supplying power to the train. Therefore, the state of charge of the on-board battery (the state of charge of the on-board battery after offsetting the negative sequence current) and the remaining running power of the train are input into the second fuzzy logic controller to obtain the second output power of the on-board battery. In the above setting, the train running power required to be borne by the traction catenary is determined by the first fuzzy logic controller, and the input quantity of the second fuzzy logic controller is limited according to the output result of the first fuzzy logic controller, so that the accuracy of the input quantity of the second fuzzy logic controller can be improved, so as to improve the accuracy of obtaining the second output power, and thus the accuracy of the control method for distributing the on-board battery and the traction catenary power supply proportion of the train traction power supply can be improved, so as to improve the energy efficiency of the train running.

[0060] Meanwhile, the two fuzzy logic controllers are arranged to control the state of charge of the on-board battery and the output power of the overhead contact system at the same time, so that when the state of charge of the on-board battery and the output power of the overhead contact system fluctuate, the control method of the power supply of the train can also accurately adjust and obtain the first output power and the second output power, thereby improving the robustness of the control method of the power supply of the train in processing the power of the overhead contact system and the state of charge of the on-board battery.

[0061] As shown in Figure 2 , the working states of the on-board battery and the ground energy storage system include standby state, discharging state and charging state. Step S3 determines the negative sequence current generated by the overhead contact system according to the second circuit parameters of the on-board battery and the third circuit parameters of the ground energy storage system in different working states. The negative sequence current refers to the current generated in a three-phase power system due to unbalanced load or fault. The on-board battery and the ground energy storage system in the present application are connected with the overhead contact system, and thus the working states of the on-board battery and the ground energy storage system will affect the negative sequence current in the overhead contact system during power supply. As described above, the accuracy of the determined negative sequence current can be improved, thereby improving the accuracy of the subsequently determined compensation current, so as to facilitate the compensation current to offset the negative sequence current, and thus the stability of the power supply of the overhead contact system can be improved.

[0062] In some embodiments, when the on-board battery and the ground energy storage system are in the standby state, the on-board battery and the ground energy storage system do not have any effect on the overhead contact system, and thus the overhead contact system bears all the traction negative charges. The product of the ratio of the input voltage of the traction substation to the voltage of the overhead contact system, the load current when the train is running and a constant can be obtained and calculated to determine the negative sequence current of the overhead contact system at this time. The calculation formula of the above-mentioned negative sequence current is as follows: ; wherein, is the negative sequence current, is the ratio of the input voltage of the traction substation to the voltage of the overhead contact system, is the load current when the train is running. That is, the calculation formula of the above-mentioned negative sequence current can be used to determine the negative sequence current of the overhead contact system when the on-board battery and the ground energy storage system are in the standby state.

[0063] In some embodiments, when the on-board battery and the ground energy storage system are in the discharging state, the electric energy obtained by the on-board battery and the ground energy storage system from the overhead contact line can be reduced, so that the peak value of the traction negative charge borne by the overhead contact line can be reduced, thereby reducing the negative sequence current in the overhead contact line. By obtaining the ratio of the input voltage of the traction substation to the voltage of the overhead contact line, the active component of the operating power of the train, the reactive component of the operating power of the train, and the discharging current of the on-board battery and the ground energy storage system, the negative sequence current of the overhead contact line at this time can be determined. The calculation formula of the above-mentioned negative sequence current is as follows: ; wherein, is the active component of the operating power of the train, is the discharging current of the on-board battery and the ground energy storage system, is the reactive component of the operating power of the train. That is, the negative sequence current of the overhead contact line when the on-board battery and the ground energy storage system are in the discharging state can be determined by the above-mentioned calculation formula of the negative sequence current.

[0064] In some embodiments, when the on-board battery and the ground energy storage system are in the charging state, the on-board battery and the ground energy storage system need to obtain electric energy from the external power grid. At this time, if the on-board battery and the ground energy storage system are charged through the overhead contact line, the peak value of the traction negative charge borne by the overhead contact line will be increased, so that the negative sequence current in the overhead contact line will be increased. The calculation formula of the above-mentioned negative sequence current is as follows: ; wherein, is the charging current of the overhead contact line. That is, the negative sequence current of the overhead contact line when the on-board battery and the ground energy storage system are charged can be calculated by the above-mentioned calculation formula of the negative sequence current.

[0065] If the on-board battery and the ground energy storage system are charged by the electric energy generated during the braking of the train, the on-board battery and the ground energy storage system do not have any impact on the overhead contact line, so that the negative sequence current in the overhead contact line will not be affected. The calculation formula of the negative sequence current of the overhead contact line in the above-mentioned state is as follows: ; wherein, is the current returned to the overhead contact line during the braking of the train. That is, the negative sequence current in the overhead contact line when the on-board battery and the ground energy storage system are charged by the electric energy generated during the braking of the train can be calculated by the above-mentioned calculation formula of the negative sequence current of the overhead contact line.

[0066] As Figure 2As shown, step S4 determines the respective compensation currents of the ground energy storage system and the on-board battery in any working state based on the negative sequence current and the preset standard negative sequence current. In the present application, the preset standard negative sequence current is the 95% probability value of the national standard allowable negative sequence current. The 95% probability value of the negative sequence current is the current value below or equal to which the negative sequence current exists for 95% of the time within a statistical time (which can be one day, one week, or one month). In the above setting, the corresponding compensation current is calculated according to the negative sequence current in the working state of the different ground energy storage system and the on-board battery, which can improve the accuracy of the compensation current calculation, thereby facilitating the compensation current to offset the negative sequence current, and facilitating to improve the stability of the traction catenary power supply.

[0067] The standard negative sequence current includes a preset probability negative sequence current and a maximum probability negative sequence current. In the present application, the calculation formulas of the preset probability negative sequence current and the maximum probability negative sequence current are as follows: ; wherein, is the short-circuit capacity of the public connection point in the traction catenary, and the public connection point is the circuit connection point of the traction catenary and the train, is the voltage of the traction catenary. That is, the preset probability negative sequence current and the maximum probability negative sequence current can be calculated by the above calculation formulas of the preset probability negative sequence current and the maximum probability negative sequence current. As shown in step S4, Figure 9 the step of determining the respective compensation currents of the ground energy storage system and the on-board battery in any working state includes: Step S41: obtaining a first probability corresponding to the preset probability negative sequence current and a second probability, the second probability being a standard probability of the preset probability negative sequence current. In the above setting, the first probability is the probability corresponding to the 95% probability value of the negative sequence current, and obtaining the above first probability and second probability is conducive to subsequent determination of the compensation current.

[0068] Step S42: obtaining a first maximum probability and a second maximum probability corresponding to the maximum probability negative sequence current, the second maximum probability being a standard probability of the maximum probability negative sequence current. In the above setting, the maximum probability negative sequence current is the maximum probability value of the national standard allowable negative sequence current, that is, the current value below or equal to which the negative sequence current exists for all time within a statistical time (which can be one day, one week, or one month), and the first maximum probability is the probability corresponding to the maximum probability value of the negative sequence current. Obtaining the above first maximum probability and second maximum probability is conducive to subsequent determination of the compensation current.

[0069] Step S43: obtaining the preset probability current, the maximum probability current, the active component and the reactive component of the operating power. The above setting is conducive to subsequent determination of the compensation current.

[0070] Step S44: comparing the first probability and the second probability, and comparing the first maximum probability and the second maximum probability, and determining the compensation current based on the negative sequence current, the preset probability negative sequence current, the maximum probability negative sequence current, the preset probability current, the maximum probability current, the active component and the reactive component of the operating power. Through the above setting, the compensation current required to be applied in the traction catenary under different probability conditions is distinguished and determined, so as to improve the accuracy of the determined compensation current, thereby facilitating the compensation current to offset the negative sequence current, and further improving the stability of the traction catenary power supply.

[0071] For example, the first probability is set to 1.3%, the first maximum probability is set to 2.6%, the preset probability negative sequence current is set to 0.5%, the preset probability current is set to 0.3%, the maximum probability negative sequence current is set to 0.7%, and the maximum probability current is set to 0.4%. For example, taking 1.3% as the second probability and 2.6% as the second maximum probability, the compensation current of the ground energy storage system and the vehicle-mounted battery under any working state includes the following three cases. In some embodiments, when the first probability is greater than the second probability, and the first maximum probability is greater than the second maximum probability, and the preset probability negative sequence current is greater than the preset probability current, and the maximum probability negative sequence current is greater than the maximum probability current, that is, the following condition is met: the calculation formula of the compensation current at any time is as follows: ; wherein, is the negative sequence current at any time, is the compensation current at any time, is the useful power component of the operating power of the train at any time, is the useless power component of the operating power of the train at any time. That is, the compensation current at any time is determined by the above relationship of the compensation current.

[0072] In some embodiments, when the first probability is greater than the second probability, and the first maximum probability is not greater than the second maximum probability, and the preset probability negative sequence current is greater than the preset probability current, and the maximum probability negative sequence current is less than the maximum probability current, that is, the following condition is met: the calculation formula of the compensation current at any time is as follows: ; That is, the compensation current at any time is determined by the above relationship of the compensation current. ,​​​​​​​​​​​ the compensation current at the moment.

[0073] In some embodiments, when the first probability is not greater than the second probability, and the first maximum probability is greater than the second maximum probability, and the preset probability negative sequence current is less than the preset probability current, and the maximum probability negative sequence current is greater than the maximum probability current, i.e. when the following conditions are met , , , the calculation formula of the compensation current at any moment is as follows: ; i.e. the compensation current at the moment is determined by the relationship formula of the compensation current described above , , , .

[0074] It should be noted that according to the national standard GB / T 15543-2008 "Power quality three-phase voltage imbalance", the 95% probability value of the negative sequence voltage imbalance degree caused by each load connected to the public connection point (PPC) at the public connection point (PPC) caused by a single user is not greater than 1.3%, and the maximum value is not greater than 2.6%. That is, in the present application, the second probability is preset to 1.3%, and the second maximum probability is preset to 2.6%.

[0075] In the present application, after the compensation current is determined, the vehicle-mounted battery and the ground energy storage system simultaneously output the required compensation current to the public connection point to offset the negative sequence current generated when the train is electrically connected to the traction catenary, thereby improving the stability of the traction catenary when supplying power to the train.

[0076] Specifically, as shown in Figure 10 , based on the negative sequence current and the preset standard negative sequence current, the step of determining the respective compensation currents of the ground energy storage system and the vehicle-mounted battery in any working state includes: Step S1001: Obtain the ratio of the input voltage of the traction substation to the voltage of the traction catenary of the vehicle-mounted battery and the ground energy storage system in different working states. The above setting is beneficial to subsequent determination of the negative sequence current.

[0077] Step S1002: Obtain the product of the running power of the train, the first circuit parameter of the traction catenary, the ratio of the input voltage of the traction substation to the voltage of the traction catenary, and a constant, to determine the negative sequence current. Since the vehicle-mounted battery and the ground energy storage system in different working states will affect the negative sequence current of the traction catenary, determining the negative sequence current according to the working state of the vehicle-mounted battery and the ground energy storage system can improve the accuracy of the negative sequence current, and the specific steps of determining the negative sequence current have been described in the foregoing, and will not be described here.

[0078] Step S1003: comparing the first probability and the second probability, and comparing the first maximum probability and the second maximum probability, and determining the compensation current of the on-board battery and the ground energy storage system in different working states based on the corresponding current of the on-board battery and the ground energy storage system in different working states, the preset probability negative sequence current, the maximum probability negative sequence current, the preset probability current, the maximum probability current, the active component and the reactive component of the operating power. Since the on-board battery and the ground energy storage system in different working states will affect the negative sequence current of the traction catenary, so that the compensation current for offsetting the negative sequence current is changed synchronously, in the above setting, by determining the negative sequence current of the traction catenary corresponding to the on-board battery and the ground energy storage system in different working states, the accuracy of determining the compensation current is improved, and the specific steps of determining the compensation current are described above and will not be repeated here.

[0079] Step S5: the traction catenary supplies power to the train at the first output power, the on-board battery supplies power to the train at the second output power, and the on-board battery and the ground energy storage system offset the negative sequence current generated by the traction catenary with the respective compensation currents.

[0080] The embodiment also provides a control system for traction power supply of a train, which is used to drive the train to run. The system includes a power supply device and a control device. The power supply device is used to provide electric energy, and includes a traction catenary, an on-board battery and a ground energy storage system. The control device is electrically connected with the power supply device, and the control device executes the control method for traction power supply of the train when receiving the electric energy output by the power supply device.

[0081] In the above setting, the power supply device includes the on-board battery and the traction catenary, and the control device controls the power supply device to supply power to the train according to the control method for traction power supply of the train, that is, the control device allocates the output power of the on-board battery and the traction catenary according to the control method for traction power supply of the train, so that the on-board battery and the traction catenary supply power to the train according to the output power, thereby reducing the demand for output power of the traction catenary when supplying power to the train, so as to reduce the volume of the traction transformer, and further reduce the energy consumption of the train when carrying the traction transformer to run, thereby improving the energy efficiency of the train when running.

[0082] For example, Figure 11As shown, the train is equipped with motors that drive its operation. The train's traction power supply control system also includes traction transformers, converters, transformers, PWM rectifiers, and inverters. A traction transformer is a voltage conversion device in the control system of electrified railways and rail transit traction power supply, used to convert current from the high-voltage grid into current suitable for the voltage level of the traction contact network. A converter is an AC / DC conversion device used to convert AC power in the traction contact network into DC power for storage in a ground energy storage system, or to convert DC power in the ground energy storage system into AC power for transmission to the traction contact network. A transformer is a device that converts AC power of one voltage and current level into current of another voltage and current level without changing the frequency, using the principle of electromagnetic induction; it is used to convert AC power in the traction contact network into current suitable for train operation. A PWM rectifier is a current conversion device that uses fully controlled power devices and pulse width modulation (PWM) technology to rectify the circuit. An inverter is a device that converts direct current (DC) to alternating current (AC). It is used to convert the DC power from the onboard battery into AC power capable of driving the motor. In this application, the traction contact network draws current from the traction transformer and supplies power to the train. The onboard battery is connected to the train's motor via the inverter and drives the motor to rotate, thus propelling the train. The onboard battery is connected to the traction contact network via a transformer and a PWM rectifier, allowing the traction contact network to charge the onboard battery and enabling the onboard battery to offset the negative sequence current in the traction contact network through compensation current. A ground-based energy storage system is connected to the train and the traction contact network via a converter, allowing the ground-based energy storage system to store excess electrical energy during train operation and also enabling the ground-based energy storage system to offset the negative sequence current in the traction contact network through compensation current.

[0083] Specifically, such as Figure 12 As shown, the on-board battery includes a series battery link, a battery fuse contactor, and a fuse switch. The series battery link comprises multiple battery modules connected in series, with adjacent series battery links connected in parallel. In this configuration, connecting multiple battery modules in series increases the output voltage of the series battery link, thereby improving the efficiency of the on-board battery-driven motor and thus enhancing the train's energy efficiency. Simultaneously, connecting multiple series battery links in parallel ensures that the on-board battery capacity equals the sum of the capacities of all series battery links, thereby increasing the on-board battery capacity and extending the time the on-board battery supplies power to the train.

[0084] It should be noted that in the present application, 6 series battery links are connected in parallel in the on-board battery, and 180 battery modules are connected in series in a single series battery link, so as to improve the capacity and voltage of the on-board battery.

[0085] In addition, the battery fuse line (BFL, Battery Fuse Line) is a safety protection device in the battery system, which is used to cut off the circuit connection between the on-board battery and the train. The battery fuse line is electrically connected to one end of the series battery link. The battery fuse line is provided to cut off the circuit connection between the on-board battery and the train when a fault occurs in the circuit on the train side, thereby avoiding damage to the circuit inside the on-board battery, so as to prolong the service life of the on-board battery. The battery fuse contactor (BFC, Battery Fuse Contactor) is a safety device integrating the functions of a fuse and a contactor, which is used to cut off the circuit connection inside the on-board battery. The battery fuse contactor is electrically connected to both ends of the series battery link. The battery fuse contactor is provided to cut off the circuit connection between the series battery link with a circuit fault and other series battery links when a fault occurs in any series battery link, thereby avoiding damage to the circuit of other series battery links, so as to improve the safety of the on-board battery during operation. The fuse switch (FS, Fuse Switch) is a safety device integrating the functions of a fuse and a disconnector. The fuse switch is arranged between two adjacent battery modules, which is used to electrically isolate adjacent batteries in the series battery link. The fuse switch is provided to cut off the circuit connection between the battery with a circuit fault and other batteries when a fault occurs in any battery, thereby avoiding damage to the circuit of other batteries, so as to improve the safety of the on-board battery during operation.

[0086] In the embodiments described above, all or some of the steps can be implemented by using software, hardware, firmware or any combination thereof. When implemented with software, all or some of the steps can be implemented in the form of one or more computer programs which are stored in a computer readable storage medium and executed by one or more computers. The computer readable storage medium can include one or more of a floppy drive, a flexible disk drive, a hard disk drive, a solid state drive, a magnetic tape, a CD-ROM, a DVD, a Blu-ray Disc, a memory stick, and the like. The computer readable storage medium can also include one or more of a computer readable nonvolatile memory, a computer readable volatile memory, a computer readable fransitory signal, and the like. In some embodiments, the computer readable nonvolatile memory can include one or more of a ROM, a PROM, an EPROM, an EEPROM, a flash memory, and the like. In some embodiments, the computer readable volatile memory can include one or more of a RAM, a dynamic RAM, a static RAM, and the like. The computer readable fransitory signal can include one or more of a computer readable signal stored in a server, a computer readable signal stored in a data center, a computer readable signal stored on a carrier, and the like.

[0087] It should be noted that, in the present document, the terms such as first and second are used only to differentiate one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Also, the terms "comprising", "containing", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include those elements solely, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0088] Each of the embodiments in the present document is described in a related manner, and the same or similar parts among the embodiments can be referred to each other. Each of the embodiments focuses on the difference from other embodiments. In particular, for the system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the description of the method embodiments. The above only describes the preferred embodiments of the present application, and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control method of a traction power supply of a train, characterized by, The method comprises the following steps: obtaining the running power of the train, the first circuit parameter of the traction catenary, the second circuit parameter of the on-board battery, and the third circuit parameter of the ground energy storage system, wherein any of the circuit parameters comprises resistance, voltage and current; determining the state of charge of the on-board battery based on the second circuit parameter, and inputting the state of charge, the first circuit parameter and the running power of the train into a preset fuzzy logic model to obtain the first output power of the traction catenary and the second output power of the on-board battery; determining the negative sequence current generated by the traction catenary according to the second circuit parameter of the on-board battery and the third circuit parameter of the ground energy storage system in different working states, wherein the working states include standby state, discharging state and charging state; determining the respective compensation currents of the ground energy storage system and the on-board battery in any of the working states based on the negative sequence current and a preset standard negative sequence current; the traction catenary supplies power to the train at the first output power, the on-board battery supplies power to the train at the second output power, and the on-board battery and the ground energy storage system offset the negative sequence current generated by the traction catenary with the respective compensation currents.

2. The control method of the power supply for traction of a train according to claim 1, characterized by, The method further comprises the following steps for determining the state of charge of the on-board battery based on the second circuit parameter: obtaining the open-circuit voltage, output voltage and internal resistance of the on-board battery to determine the internal current of the on-board battery; obtaining the discharging time of the on-board battery, and determining the maximum value of the battery capacity of the on-board battery according to the product of the internal current and the discharging time of the on-board battery; obtaining the state of charge of the on-board battery based on the maximum value of the battery capacity and the discharging time of the on-board battery.

3. The control method of the power supply for traction of a train according to claim 1, characterized by, The method further comprises the following steps for obtaining the first output power of the traction catenary: determining the first membership function corresponding to the running power of the train and the second membership function corresponding to the state of charge of the on-board battery; obtaining the first fuzzy subset of the first membership function and the second fuzzy subset of the second membership function, and obtaining the third membership function according to the corresponding relationship between the first fuzzy subset and the second fuzzy subset; de-fuzzifying the third membership function based on the weighted average method to obtain the first proportion factor and the first barycentric value, and obtaining the product of the first barycentric value and the first proportion factor to obtain the first output power.

4. The control method of the power supply for traction of a train according to claim 3, characterized by, The method further comprises the following steps for obtaining the second output power of the traction catenary: obtaining the difference between the running power of the train and the first output power to obtain the remaining running power of the train; substituting the remaining running power of the train and the state of charge of the on-board battery into the membership function to obtain the fourth membership function corresponding to the remaining running power of the train; obtaining the third fuzzy subset of the fourth membership function, and obtaining the fifth membership function according to the corresponding relationship between the second fuzzy subset and the third fuzzy subset; de-fuzzifying the fifth membership function based on the weighted average method to obtain the second proportion factor and the second barycentric value, and obtaining the product of the second barycentric value and the second proportion factor to obtain the second output power.

5. The control method of the power supply for traction of a train according to claim 3, characterized by, The standard negative sequence current includes a preset probability negative sequence current and a maximum probability negative sequence current, and the compensation current of the ground energy storage system and the vehicle-mounted battery in any working state is determined, including: obtaining a first probability corresponding to the preset probability negative sequence current and a second probability, the second probability being a standard probability of the preset probability negative sequence current; obtaining a first maximum probability corresponding to the maximum probability negative sequence current and a second maximum probability, the second maximum probability being a standard probability of the maximum probability negative sequence current; obtaining a preset probability current, a maximum probability current, an active component and a reactive component of the operating power; comparing the first probability and the second probability, and comparing the first maximum probability and the second maximum probability, and determining the compensation current based on the negative sequence current, the preset probability negative sequence current, the maximum probability negative sequence current, the preset probability current, the maximum probability current, the active component and the reactive component of the operating power.

6. The control method of the power supply for traction of a train according to claim 5, characterized by, The compensation current of the ground energy storage system and the vehicle-mounted battery in any working state is determined based on the negative sequence current and the preset standard negative sequence current, including: obtaining a ratio of an input voltage of a traction substation to a voltage of a traction catenary of the vehicle-mounted battery and the ground energy storage system in different working states; obtaining a product of the operating power of the train, a first circuit parameter of the traction catenary, the ratio of the input voltage of the traction substation to the voltage of the traction catenary, and a constant, to determine the negative sequence current; comparing the first probability and the second probability, and comparing the first maximum probability and the second maximum probability, and determining the compensation current of the vehicle-mounted battery and the ground energy storage system in different working states based on the corresponding negative sequence current of the vehicle-mounted battery and the ground energy storage system in different working states, the preset probability negative sequence current, the maximum probability negative sequence current, the preset probability current, the maximum probability current, the active component and the reactive component of the operating power.

7. The control method of the power supply for traction of a train according to claim 5, characterized by, The compensation current of the ground energy storage system and the vehicle-mounted battery in any working state is determined, when the first probability is greater than the second probability, and the first maximum probability is greater than the second maximum probability, and the preset probability negative sequence current is greater than the preset probability current, and the maximum probability negative sequence current is greater than the maximum probability current, the calculation formula of the compensation current being as follows: ； The compensation current of the ground energy storage system and the vehicle-mounted battery in any working state is determined, when the first probability is greater than the second probability, and the first maximum probability is not greater than the second maximum probability, and the preset probability negative sequence current is greater than the preset probability current, and the maximum probability negative sequence current is less than the maximum probability current, the calculation formula of the compensation current being as follows: ； wherein is the ratio of the input voltage of the traction substation to the voltage of the traction catenary, is the active component of the operating power, is the compensation current, is the reactive component of the operating power, is the preset probability current, is the negative sequence current, is the preset probability negative sequence current, is the maximum probability current.

8. A control system of a traction power supply of a train for driving a train operation, characterized by, including: a power supply device and a central control device, the power supply device being used for providing electric energy, and including a traction catenary, a vehicle-mounted battery and a ground energy storage system, the central control device being electrically connected with the power supply device, and the central control device executing the control method of the traction power supply in any one of claims 1 to 7 when receiving the electric energy output by the power supply device.

9. A control system for a traction battery according to claim 8, characterised in that, The on-board battery comprises: a series battery link comprising a plurality of battery modules connected in series, adjacent series battery links are connected in parallel; a battery line fuse for cutting off the circuit connection between the on-board battery and the train, the battery line fuse being electrically connected between the train and one end of the series battery link; a battery fuse contactor for cutting off the internal circuit connection of the on-board battery, the battery fuse contactor being electrically connected to both ends of the series battery link; and a fuse switch for electrically isolating adjacent battery modules in the series battery link, the fuse switch being arranged between two adjacent battery modules.

10. An electronic device, comprising: Comprising: a memory, a processor and a computer program stored on the memory, the processor being arranged to run the computer program to perform the control method of any one of claims 1 to 7.

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