Method and device for identifying abnormal working conditions of vehicle-grid coupling system

Abstract

The present application provides a method and device for identifying abnormal operating conditions of a vehicle-grid coupling system, and relates to the technical field of abnormal operating condition identification of vehicle-grid coupling systems. The method includes: constructing an electrical model of the traction power supply system according to the short-circuit capacity of the external power grid in the power system and the first electrical parameter of the traction power supply system in the vehicle-grid coupling system; constructing operating load simulation models of various types of electric locomotives with different departure intervals according to the second electrical parameters of the electric locomotive operation in the vehicle-grid coupling system and the operating diagram of the electric locomotive type under different departure intervals; coupling the electrical model and the operating load simulation model to obtain a vehicle-grid coupling flow model; solving the vehicle-grid coupling flow model, and determining the abnormal operating conditions of the vehicle-grid coupling system based on the solution results. It can realize the unified identification of abnormal operating conditions of various vehicle-grid coupling systems, and improve the efficiency of identifying abnormal operating conditions in the vehicle-grid coupling system.

Description

Technical Field

[0001] The present invention relates to the field of rail transit detection technology, and in particular to a method and device for identifying abnormal working conditions of a vehicle-grid coupling system. Background Art

[0002] In recent years, the domestic electrified railway has developed rapidly. The cross-integration of various lines, increasingly tight traffic organization, and the combined operation of various electric locomotives have put forward higher requirements for the safe and stable operation of high-speed railways. The vehicle-grid coupling system composed of the traction power supply system and the electric locomotive is an important part of the electrified railway.

[0003] The electrical coupling mechanism inside the vehicle-grid coupling system is complex, and there are many abnormal matching conditions of the vehicle-grid coupling. Accurately identifying abnormal matching conditions is of great significance to the safe and stable operation of the traction power supply system and the EMU. However, it is currently impossible to uniformly identify the abnormal conditions of various vehicle-grid coupling systems, resulting in low identification efficiency. Summary of the invention

[0004] The purpose of the present invention is to provide a method and device for identifying abnormal operating conditions of a vehicle-grid coupling system in view of the deficiencies in the above-mentioned prior art, so as to achieve unified identification of abnormal operating conditions of multiple vehicle-grid coupling systems and improve the efficiency of identifying abnormal operating conditions.

[0005] To achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, an embodiment of the present application provides a method for identifying abnormal operating conditions of a vehicle-grid coupling system, comprising: constructing an electrical model of the traction power supply system based on the short-circuit capacity of an external power grid in the power system and a first electrical parameter of the traction power supply system in the vehicle-grid coupling system; constructing operating load simulation models of multiple types of electric locomotives with different departure intervals based on second electrical parameters of the operation of the electric locomotive in the vehicle-grid coupling system and an operating diagram of the electric locomotive type at different departure intervals; coupling the electrical model and the operating load simulation model to obtain a vehicle-grid coupling power flow model; solving the vehicle-grid coupling power flow model, and determining the abnormal operating condition of the vehicle-grid coupling system based on the solution result.

[0007] In combination with the first aspect, in a possible implementation method, the electrical model of the traction power supply system is constructed according to the short-circuit capacity of the external power grid in the power system and the first electrical parameter of the traction power supply system in the vehicle-grid coupling system, including: determining the equivalent model of the traction transformer and the equivalent model of the traction network according to the first electrical parameter of the traction power supply system, the short-circuit capacity of the external power grid, and the third electrical parameter per unit length of the external power grid line; wherein the first electrical parameter includes the connection angle of the traction transformer, the voltage and current of the primary side, and the voltage and current of the secondary side; determining the impedance and admittance equivalent model of the traction network according to the line properties of the traction network; determining the electrical model of the traction power supply system according to the equivalent model of the traction transformer, the equivalent model of the traction network, and the impedance and admittance equivalent model of the traction network.

[0008] In combination with the first aspect, in a possible implementation method, the equivalent model of the traction transformer and the equivalent model of the traction network are determined according to the first electrical parameter of the traction power supply system, the short-circuit capacity of the external power grid, and the third electrical parameter per unit length of the external power grid line, including: determining the conversion matrix corresponding to the first electrical parameter through the conversion formula between the first electrical parameters and the connection angle of the traction transformer; determining the total impedance of the power system according to the voltage level of the external power grid and the short-circuit capacity; determining the equivalent model of the traction transformer and the equivalent model of the traction network according to the total impedance of the power system.

[0009] In combination with the first aspect, in a possible implementation method, the impedance admittance equivalent model of the traction network is determined according to the line properties of the traction network, including: determining the impedance admittance equivalent model of the traction network at a preset frequency according to the line properties of the traction network and the fourth electrical parameter of the line unit length of the traction network; the impedance admittance equivalent model includes an impedance admittance matrix per unit length and a parallel impedance admittance matrix per unit length.

[0010] In combination with the first aspect, in a possible implementation method, the operation load simulation model of multiple types of electric locomotives with different departure intervals is constructed according to the second electrical parameters of the electric locomotive operation in the vehicle-grid coupling system and the operation diagram of the electric locomotive type at different departure intervals, including: determining the second electrical parameter of the electric locomotive operation according to the force during the operation of the electric locomotive, and determining the second electrical parameter traction model of the electric locomotive operation according to the second electrical parameter; the second electrical parameter includes active power and reactive power; determining the dimension of the electric locomotive data matrix and the elements of the electric locomotive data matrix according to the second electrical parameter traction model and the actual number of electric locomotives departing within the flow calculation time period; determining the departure interval and the actual number of electric locomotives departing within the flow calculation time period according to the operation diagram of the electric locomotive, and constructing the operation load simulation models of multiple electric locomotives corresponding to different departure intervals in combination with the electric locomotive data matrix.

[0011] In combination with the first aspect, in a possible implementation method, the solving of the vehicle-grid coupled power flow model includes: using a preset algorithm to determine the fifth electrical parameter of each electrical node of the traction network, iteratively solving the voltage of each electric locomotive, and updating the current according to the voltage of the electric locomotive; updating the voltage of the electrical node according to the current until the voltage of all electric locomotives meets a preset convergence condition.

[0012] In combination with the first aspect, in a possible implementation method, solving the vehicle-grid coupled power flow model includes: determining whether the voltage deviation within the power flow calculation time period is greater than a first preset threshold based on the solution result, and if the voltage deviation is greater than the first preset threshold, identifying that the voltage is in an abnormal operating condition; determining whether the distortion rate of the harmonic voltage of the electrical node at the outlet of the traction substation is greater than a second preset threshold based on the solution result, and if the distortion rate of the harmonic voltage is greater than the second preset threshold, identifying that the harmonic voltage is in an abnormal operating condition.

[0013] In the second aspect, an embodiment of the present application provides an apparatus for identifying abnormal operating conditions of a vehicle-grid coupling system, comprising: an electrical model building module, configured to build an electrical model of the traction power supply system according to the short-circuit capacity of the external power grid in the power system and the first electrical parameter of the traction power supply system in the vehicle-grid coupling system; an operating load simulation model building module, configured to build operating load simulation models of multiple types of electric locomotives with different departure intervals according to the second electrical parameters of the electric locomotive operation in the vehicle-grid coupling system and the operating diagrams of the electric locomotive types at different departure intervals; a vehicle-grid coupling flow model determination module, configured to couple the electrical model and the operation load simulation model to obtain a vehicle-grid coupling flow model; an abnormal operating condition identification module, configured to solve the vehicle-grid coupling flow model and determine the abnormal operating condition of the vehicle-grid coupling system based on the solution result.

[0014] In a third aspect, an embodiment of the present application provides a device, comprising: a processor; a memory for storing processor-executable instructions; when the processor executes the executable instructions, it implements the method described in the first aspect or any possible implementation method of the first aspect.

[0015] In a fourth aspect, an embodiment of the present application provides a non-volatile computer-readable storage medium, wherein the non-volatile computer-readable storage medium includes a device for storing a computer program or instructions, and when the computer program or instructions are executed, the method described in the first aspect or any possible implementation method of the first aspect is implemented.

[0016] The beneficial effects of the present application are as follows: by constructing an electrical model of the traction power supply system and operating load simulation models of various types of electric locomotives with different departure intervals, and then coupling the electrical model with the operating load simulation model to obtain a vehicle-grid coupling power flow model, the vehicle-grid coupling power flow model is solved, and based on the solution results, the abnormal operating conditions of the vehicle-grid coupling system are identified. The vehicle-grid coupling power flow model can be used to uniformly identify different abnormal operating conditions of the vehicle-grid coupling system, thereby improving the efficiency of identifying abnormal operating conditions of the vehicle-grid coupling system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A flow chart of a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application;

[0019] Figure 2 A flow chart of a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application;

[0020] Figure 3 A schematic diagram of an impedance-admittance equivalent model of a traction network in a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application;

[0021] Figure 4 A schematic diagram of a traction network structure in a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application;

[0022] Figure 5 A flow chart of a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application;

[0023] Figure 6 A schematic diagram of the principle of a power system and a traction transformer in a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application;

[0024] Figure 7 A schematic diagram of an equivalent circuit of a secondary side of a traction substation in a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application;

[0025] Figure 8 A flow chart of a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application;

[0026] Fig. 9 A schematic diagram of the structure of a device for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application;

[0027] Fig.10 A schematic diagram of the structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that, in the absence of conflict, the features in the embodiments of the present application may be combined with each other.

[0030] Figure 1 A flow chart of a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application is shown as follows: Figure 1As shown, the method includes steps S110 to S140, which are specifically as follows.

[0031] Step S110: constructing an electrical model of the traction power supply system according to the short-circuit capacity of the external power grid in the power system and the first electrical parameter of the traction power supply system in the vehicle-grid coupling system.

[0032] In the embodiment of the present application, the power system includes an external power grid and a traction power supply system. The traction power supply system includes a traction substation, a traction network, a substation, rails, etc. The vehicle-grid coupling system consists of a traction power supply system and an electric locomotive.

[0033] The first electrical parameters, i.e., the electrical parameters of the traction power supply system, may specifically be the electrical parameters of the traction transformer, such as: the connection angle of the traction transformer, the primary voltage of the traction transformer, the primary current of the traction transformer, the secondary voltage of the traction transformer, the secondary current of the traction transformer, etc.

[0034] like Figure 2 As shown, it is a flow chart of the method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application, including the following steps S210 to S230.

[0035] Step S210: Determine the equivalent model of the traction transformer and the equivalent model of the traction network according to the first electrical parameter of the traction power supply system, the short-circuit capacity of the external power grid, and the third electrical parameter per unit length of the external power grid line. The first electrical parameter includes the connection angle of the traction transformer, the voltage and current of the primary side, and the voltage and current of the secondary side.

[0036] In the embodiment of the present application, the third electrical parameter, that is, the electrical parameter per unit length of the external power grid line, may be specifically, the impedance per unit length, length, etc. of the external power grid line (high-voltage transmission line).

[0037] Exemplarily, the equivalent model of the traction transformer may be the secondary equivalent leakage reactance of the traction transformer. The equivalent model of the traction network may be the equivalent impedance of the traction network.

[0038] In actual operation, the total impedance of the power system can be determined based on the first electrical parameter of the traction power supply system, the short-circuit capacity of the external power grid, and the third electrical parameter of the unit length of the external power grid line. Then, based on the total impedance of the power system, the secondary equivalent impedance of the power system and the equivalent model of the traction transformer are determined respectively. Finally, based on the secondary equivalent impedance of the power system and the equivalent model of the traction transformer, the equivalent model of the traction network is determined.

[0039] like Figure 5FIG. 2 is a flow chart of a method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application. The above step S210 may include the following steps S510 to S530.

[0040] Step S510: Determine a conversion matrix corresponding to the first electrical parameter through a conversion formula between the first electrical parameters and a connection angle of the traction transformer.

[0041] For example, the voltage level of the external power grid is 220 kV, the short-circuit capacity of the external power grid is 1500 MVA, and the traction transformer adopts the Vv connection form, such as Figure 6 As shown in the figure, A, B, and C represent the three phases of the external three-phase power grid, T1 represents the contact wire of the left power supply arm of the traction substation, T2 represents the contact wire of the right power supply arm of the traction substation, and R represents the rail. Indicates the A phase current, represents the B phase current, represents the C phase current, Indicates the left side of the traction substation ( ) The traction grid voltage of the power supply arm, Indicates the right side of the traction substation ( ) Traction grid voltage of the power supply arm.

[0042] Exemplarily, the conversion formula between the first electrical parameters can be shown as the following formula (1):

[0043] (1)

[0044] in, , , , They are the left side of the secondary side of the traction transformer ( ) Power supply arm, right ( ) Phase voltage and phase current of the power supply arm, , , are the phase voltages of the external three-phase grid A, B, and C, , , They are the phase currents of the external three-phase power grid A, B, and C, N is the primary and secondary voltage conversion matrix, and M is the primary and secondary current conversion matrix.

[0045] Exemplarily, the primary-secondary voltage conversion matrix N and the primary-secondary current conversion matrix M are shown in the following formula (2):

[0046] (2)

[0047] in, is the connection angle of the traction transformer. The connection angles of the traction transformer (the ratio of the left and right power supply arms) are .

[0048] Step S520: Determine the total impedance of the power system according to the voltage level and short-circuit capacity of the external power grid.

[0049] In actual operation, this step can first determine the impedance of the power system based on the voltage level and short-circuit capacity of the external power grid, then determine the line impedance based on the unit length impedance of the line, and finally determine the total impedance of the power system based on the impedance of the power system and the unit length impedance of the line.

[0050] Exemplarily, the power system impedance can be determined according to the following formula (3):

[0051] (3)

[0052] in, is the power system impedance, The voltage level of the external power grid. is the short-circuit capacity of the local grid, It is a plural unit.

[0053] Exemplarily, the total impedance of the power system can be determined according to the following formula (4):

[0054] (4)

[0055] in, is the total impedance of the power system, is the power system impedance, is the line impedance of the three-phase grid, is the unit line impedance of the three-phase grid, is the length of the high voltage transmission line.

[0056] Step S530: Determine the equivalent model of the traction transformer and the equivalent model of the traction network according to the total impedance of the power system.

[0057] In actual operation, this step can first determine the secondary side equivalent impedance of the power system and the equivalent model of the traction transformer based on the total impedance of the power system, and then determine the equivalent model of the above-mentioned traction network based on the secondary side equivalent impedance of the power system and the equivalent model of the traction transformer.

[0058] For example, Figure 7 The equivalent circuit diagram of the secondary side of the traction substation is shown in the figure. Indicates the current of the left power supply arm input by the traction transformer. is the secondary equivalent impedance of the left power supply arm, is the secondary equivalent impedance of the right power supply arm, is the equivalent impedance of the middle branch of the equivalent circuit on the traction network side, It indicates the equivalent potential of the three-phase voltage through the traction transformer to the left power supply arm. It indicates the equivalent potential of the three-phase voltage through the traction transformer to the right power supply arm. Indicates the traction grid voltage of the left power supply arm of the traction substation. represents the traction grid voltage of the right power supply arm of the traction substation. The secondary equivalent impedance of the power system can be determined according to the following formula (5):

[0059] (5)

[0060] in, is the secondary equivalent impedance of the power system, N is the primary and secondary voltage conversion matrix, M is the primary and secondary current conversion matrix, is the total impedance of the power system.

[0061] Exemplarily, the equivalent model of the traction transformer can be determined according to the following formula (6):

[0062] (6)

[0063] in, is the secondary equivalent leakage reactance of the traction transformer, is the short-circuit voltage percentage of the traction transformer, is the rated voltage of the secondary side of the traction transformer, is the rated capacity of the traction transformer.

[0064] Exemplarily, the equivalent model of the traction network can be determined according to the following formula (7):

[0065] (7)

[0066] in, is the secondary equivalent impedance of the left power supply arm, is the secondary equivalent impedance of the power system, is the secondary equivalent leakage reactance of the traction transformer, is the secondary equivalent impedance of the right power supply arm, It is the equivalent impedance of the intermediate branch of the equivalent circuit on the traction network side.

[0067] In the process of establishing the equivalent model of the traction transformer and the equivalent model of the traction network, the present application takes into account the short-circuit capacity of the external power grid and the electrical characteristics of the traction power supply system, and the constructed equivalent model of the traction transformer and the equivalent model of the traction network are more accurate.

[0068] Step S220: Determine the impedance-admittance equivalent model of the traction network according to the line attributes of the traction network. In the embodiment of the present application, the impedance-admittance equivalent model of the traction network at a preset frequency is determined according to the line attributes of the traction network and the fourth electrical parameter per unit length of the line of the traction network. The impedance-admittance equivalent model includes an impedance-admittance matrix per unit length and a parallel impedance-admittance matrix per unit length.

[0069] The line attributes of the traction network may be the types of conductors such as contact wires, load-bearing cables, negative feeders, and rails in the line. The line attributes of the traction network may be the types of conductors such as contact wires, load-bearing cables, negative feeders, and rails in the line.

[0070] The fourth electrical parameter, namely the electrical parameter per unit length of the traction network line, may specifically be impedance per unit length, length, etc.

[0071] The preset frequency may be any frequency that conforms to theory or practice, such as 50 Hz, 100 Hz, etc., and is not limited here.

[0072] For example, the impedance-admittance matrix per unit length can be obtained by solving the Carson formula. The unit self-impedance of wire i is as shown in formula (8), and the unit mutual impedance between wire i and wire j is as shown in formula (9), which are specifically shown as follows:

[0073] (8)

[0074] (9)

[0075] in, is the unit self-impedance of conductor i, is the unit resistance, is the current frequency, is the vacuum permeability, It is the equivalent depth of the conductor in the ground that replaces the influence of the earth. is the equivalent radius of wire i, is the unit mutual impedance between wire i and wire j, is the distance between wire i and wire j, It is a plural unit.

[0076] For the parallel admittance of a multi-conductor transmission line, according to the electrostatic field calculation, the voltage of each conductor i to the ground Its linear charge density The relationship is shown in the following formula (10):

[0077] (10)

[0078] in, is the voltage of wire i to ground, m is the total number of wires, , is the wire i The self-potential coefficient, is the linear charge density of wire i, is the space dielectric constant, is the height of conductor i above the ground, is the equivalent radius of wire i.

[0079] The method for identifying abnormal working conditions of a vehicle-grid coupling system provided in an embodiment of the present application is, for example, that the unit length parallel impedance admittance matrix can be determined according to the following formula (11):

[0080] (11)

[0081] in, , is the capacitance coefficient matrix, is the unit length shunt impedance admittance matrix, is the potential coefficient matrix, is the self-admittance of conductor i to ground, is the current frequency, is the capacitance of wire i to ground, It is a plural unit.

[0082] For example, since the traction network architecture is a multi-conductor parallel transmission line, it belongs to a composite chain circuit. The chain network model is as follows: Figure 4 As shown in the figure, the interpretation is the same as that in formula (12). Each horizontal parallel element such as traction transformer, electric locomotive, substation, etc. is used as a section to divide the traction network into sections of different lengths. For the traction network impedance section between section k and section k+1, the node voltage equation is written as shown in the following formula (12):

[0083] (12)

[0084] in, is the impedance section of the traction network between section N-1 and section N, is the self-admittance of section N, is the node voltage of slice N, is the current of the electrical node of slice N, where N is the total number of slices. The admittance matrix of the corresponding electrical node on the left side of the above equation is obtained by staggered superposition of the admittance matrices of the longitudinal series elements between slices and the transverse parallel elements of each slice. Assuming that there are m conductors constituting the traction network, U and I are both Nm×1-order matrices, and the admittance matrix of the electrical node is an Nm×Nm-order matrix, where N is the number of slices.

[0085] When the length L between each section segment is known, each section segment can be equivalent to the impedance admittance equivalent model of the traction network (such as type II equivalent circuit) according to the unit length impedance admittance matrix and the unit length parallel impedance admittance matrix, as shown in Figure 3 As shown in the figure, represents the self-admittance of conductor m to ground, represents the self-impedance of conductor m to ground, and the calculation process is shown in the following formula (13):

[0086] (13)

[0087] in, is the impedance matrix of the π-type equivalent circuit of the traction network, is the impedance-admittance matrix per unit length, is the unit length shunt impedance admittance matrix, is the length between each section segment, It is the admittance matrix of the π-type equivalent circuit of the traction network.

[0088] In actual operation, the impedance-admittance equivalent model can be determined by using the multi-conductor transmission line theory. This is because the traction network is mainly composed of load-bearing cables, contact wires, negative feeders, rails, etc. Although its electrical structure is complex, it is still a multi-conductor transmission system in the final analysis. Therefore, the impedance-admittance equivalent model can be determined by using the multi-conductor transmission line theory.

[0089] In this way, based on the multi-conductor transmission line theory, the impedance-admittance equivalent model of the traction network is determined according to the impedance-admittance matrix per unit length and the parallel impedance-admittance matrix per unit length. The self-impedance of the conductor and the mutual impedance between the conductors are taken into account, and the impedance-admittance equivalent model of the traction network determined is more accurate.

[0090] Step S230: Determine the electrical model of the traction power supply system according to the equivalent model of the traction transformer, the equivalent model of the traction network, and the equivalent model of the impedance and admittance of the traction network.

[0091] In an embodiment of the present application, the electrical model of the above-mentioned traction power supply system can be obtained by directly combining the equivalent model of the traction transformer, the equivalent model of the traction network, and the equivalent model of the impedance and admittance of the traction network.

[0092] The present application can construct a more accurate electrical model of the traction power supply system based on consideration of the short-circuit capacity of the external power grid and the electrical parameters of the traction power supply system.

[0093] Step S120: constructing operation load simulation models of various types of electric locomotives at different departure intervals according to the second electrical parameters of the electric locomotive in the vehicle-grid coupling system and the operation diagrams of the electric locomotive types at different departure intervals.

[0094] In the embodiment of the present application, the second electrical parameter, that is, the electrical parameter of the electric locomotive, may specifically be the active power, reactive power, etc. at each speed level of the electric locomotive.

[0095] The operation diagram, i.e., the actual operation diagram of the electric locomotive, can be used to obtain information such as the departure time of each electric locomotive, the departure intervals of different electric locomotives, etc.

[0096] The operation load simulation model, in this application, is a model obtained by simulating the load conditions of multiple types (all) of electric locomotives in different departure intervals during operation. In actual operation, the types of electric locomotives started at different departure intervals may be the same or different. For example: the electric locomotive started at 8:10 is a Shaoshan-type electric locomotive, and the electric locomotive started at 9:30 is a Harmony-type electric locomotive. For another example: the electric locomotive started at 10:10 is a DC electric locomotive, and the electric locomotive started at 11:30 is an AC electric locomotive. Electric locomotives can be divided into different types based on different property standards.

[0097] like Figure 8 As shown, it is a flow chart of the method for identifying abnormal operating conditions of a vehicle-grid coupling system provided in an embodiment of the present application, wherein step S120 includes the following steps S810 to S830.

[0098] Step S810: Determine the second electrical parameter of the electric locomotive according to the force during the operation of the electric locomotive, and determine the second electrical parameter traction model of the electric locomotive according to the second electrical parameter, wherein the second electrical parameter includes active power and reactive power.

[0099] In the embodiment of the present application, the forces acting on the electric locomotive during operation mainly include the traction / braking force of the electric locomotive itself, basic resistance, additional resistance of the line ramp, friction resistance of curves, air resistance in the tunnel, etc. Therefore, it is necessary to determine the second electrical parameter traction model in combination with the electric locomotive parameters, line parameters, and tunnel parameters.

[0100] For example, for traction / braking force The solution is to assume , then, traction / braking force It can be determined according to the following formula (14):

[0101] (14)

[0102] in, The electric locomotive is at speed Traction / braking force under The electric locomotive is at speed Traction / braking force under The electric locomotive is at speed Traction / braking force under v is the running speed of the electric locomotive, , are the speeds of the electric locomotive at discrete points p and q respectively.

[0103] For example, for the basic resistance It can be determined according to the following formula (15):

[0104] (15)

[0105] in, It is the basic resistance of electric locomotive. , , is an empirical constant related to the type of electric locomotive, v is the running speed of the electric locomotive, M is the mass of the electric locomotive, g is the acceleration due to gravity.

[0106] Exemplarily, additional resistance may also be included. Determine according to the following formula (16):

[0107] (16)

[0108] in, is the additional resistance of the electric locomotive, θ is the angle between the ramp and the horizontal plane, is the radius of curvature of the curve, is the empirical coefficient of additional resistance of the tunnel, is the tunnel length.

[0109] In actual operation, the angle between the ramp and the horizontal plane can be obtained by consulting the data , Curve radius , Tunnel additional resistance empirical coefficient and tunnel length .

[0110] Furthermore, the speed of the electric locomotive is The combined force of time It can be determined according to the following formula (17):

[0111] (17)

[0112] in, The electric locomotive is at speed Traction / braking force under It is the basic resistance of electric locomotive. It is the additional resistance of the electric locomotive.

[0113] In the embodiment of the present application, the second electrical parameter of the electric locomotive can be determined according to the following formula (18):

[0114] (18)

[0115] in, is the active power of the electric locomotive, is the reactive power of the electric locomotive, The speed of the electric locomotive is The combined force of time, is the running speed of the electric locomotive, It is the power factor parameter of the electric locomotive when it leaves the factory.

[0116] Furthermore, the second electrical parameter of the electric locomotive running in the time domain with equal step size can be solved by methods such as time-space linear interpolation, so as to obtain the second electrical parameter traction model.

[0117] Exemplarily, the second electrical parameter traction model may be Dimensional data matrix. Among them, m is the total running time in the electric locomotive traction calculation results, and n is the number of information solved by the electric locomotive in the traction calculation results.

[0118] Step S820: Determine the dimension of the electric locomotive data matrix and the elements of the electric locomotive data matrix according to the second electrical parameter traction model and the actual number of electric locomotives dispatched during the power flow calculation period.

[0119] The dimension of the preset matrix can be determined according to the actual number of electric locomotives dispatched during the power flow calculation period. For example, the actual number of electric locomotives dispatched during the power flow calculation period is , then the preset matrix is Dimensional matrix.

[0120] The elements of the preset matrix are used to store the data information of the electric locomotive. The elements of the preset matrix can be determined according to the second electrical parameter traction model. Exemplarily, the elements can be determined according to the following formula (19):

[0121] (19)

[0122] in, Refers to the departure time of the next electric locomotive. Refers to the current departure time of the electric locomotive. is the total running time in the electric locomotive traction calculation results, It is the number of information solved for the electric locomotive in the traction calculation results.

[0123] Step S830: Determine the departure interval and the actual number of electric locomotives departing during the power flow calculation period according to the operation diagram of the electric locomotive, and construct operation load simulation models of various electric locomotives corresponding to different departure intervals in combination with the electric locomotive data matrix.

[0124] Among them, according to the departure interval determined by the electric locomotive operation diagram, the actual number of electric locomotive departures during the power flow calculation period, and the electric locomotive data matrix, the operation load simulation model of various types of electric locomotives with different departure intervals can be obtained. Among them, the electric locomotive data matrix represents the data information of each electric locomotive.

[0125] The present application can simulate the operating load process of various electric locomotives with different departure intervals to a great extent based on the electric locomotive operation diagram, the actual number of electric locomotive departures during the flow calculation time period, and the electric locomotive data matrix representing the data information of each electric locomotive, and obtain a more accurate operating load simulation model of various electric locomotives with different departure intervals.

[0126] Step S130: coupling the electrical model and the operating load simulation model to obtain a vehicle-grid coupled power flow model.

[0127] The model coupling in this step can be achieved by connecting the running load simulation model to the power element model to obtain a vehicle-grid coupling power flow model. Specifically, the electric locomotive in the running load simulation model can be equivalent to a current source and connected to the traction network in the electrical model to obtain the above vehicle-grid coupling power flow model.

[0128] Step S140: Solve the vehicle-grid coupling power flow model, and determine the abnormal working condition of the vehicle-grid coupling system based on the solution result. In the embodiment of the present application, a preset algorithm is used to determine the fifth electrical parameter of each electrical node of the traction network, the voltage of each electric locomotive is iteratively solved, and the current is updated according to the voltage of the electric locomotive. The voltage of the electrical node is updated according to the current until the voltage of all electric locomotives meets the preset convergence condition.

[0129] The solution of the vehicle-grid coupled power flow model can be solved by a power flow algorithm to obtain electrical parameters, and then the electrical parameters are iterated until the electrical parameters meet the convergence conditions. The fifth electrical parameter is the electrical parameter of each electrical node of the traction network, such as voltage, current, etc.

[0130] Exemplarily, the preset algorithm may be a power flow algorithm, such as a continuous power flow algorithm, an optimal multiplier algorithm, etc., which is not limited here.

[0131] This step updates the voltage in reverse according to the conversion formula of voltage and current. The resistance in the conversion formula is the impedance admittance matrix of the electrical node. Therefore, both voltage and current are matrices, and the voltage finally meets the preset convergence condition.

[0132] The voltage deviation during the power flow calculation period can be determined according to the following formula (20):

[0133] (20)

[0134] in, is the voltage deviation during the power flow calculation period, U is the actual voltage value, is the rated voltage value.

[0135] The time period for power flow calculation can be selected arbitrarily based on theory or actual situation, for example: select the peak period of 8:00-9:00, or 6:00-7:00. Of course, other time periods can also be selected, and there is no limitation here.

[0136] The first preset threshold can be determined based on experience or by referring to relevant materials, for example, it can be set to 10% or 15%, which is not limited here.

[0137] Among them, the harmonic voltage is obtained by Fourier decomposition of the voltage of the electrical node at the outlet of the traction substation (as shown in the following formula 21) to obtain the corresponding h-th harmonic voltage .

[0138] (twenty one)

[0139] in, is the Fourier function, It is the DC component. When the waveform is symmetrical about the upper and lower half waves on the time axis, the value is 0. , are the amplitude and phase angle of the hth harmonic content, respectively. is the fundamental frequency, It's time.

[0140] Further, exemplary, harmonic voltage content It can be determined according to the following formula (22):

[0141] (twenty two)

[0142] in, is the RMS value of the hth harmonic voltage, is the RMS value of the fundamental voltage.

[0143] Further, exemplary, the distortion rate of harmonic voltage It can be determined according to the following formula (23):

[0144] (twenty three)

[0145] in, is the RMS value of the hth harmonic voltage, is the root mean square value of the fundamental voltage, is the hth harmonic.

[0146] The first preset threshold can be determined based on experience or by referring to relevant materials, for example, it can be set to 2%, 3%, etc., which is not limited here.

[0147] In an embodiment of the present application, it is determined based on the solution result whether the voltage deviation in the flow calculation time period is greater than a first preset threshold value. If the voltage deviation is greater than the first preset threshold value, the voltage is identified as an abnormal operating condition. It is determined based on the solution result whether the distortion rate of the harmonic voltage of the electrical node at the outlet of the traction substation is greater than a second preset threshold value. If the distortion rate of the harmonic voltage is greater than the second preset threshold value, the harmonic voltage is identified as an abnormal operating condition. In this way, the abnormal operating condition of the vehicle-grid coupling system can be directly identified based on the solution result of the vehicle-grid coupling flow model, thereby improving the efficiency of identifying abnormal operating conditions of the vehicle-grid coupling system. In addition, multiple abnormal operating conditions can be identified, thereby achieving unified identification of multiple abnormal operating conditions of the vehicle-grid coupling system.

[0148] In actual operation, after an abnormal operating condition is determined, buzzers, information prompts, etc. can be used to prompt or warn relevant staff so that they can understand the abnormal operating condition in time and deal with it.

[0149] The present application constructs an electrical model of the traction power supply system and an operating load simulation model of various types of electric locomotives with different departure intervals, and then couples the electrical model with the operating load simulation model to obtain a vehicle-grid coupling power flow model, so as to solve the vehicle-grid coupling power flow model, and identify the abnormal operating conditions of the vehicle-grid coupling system based on the solution results. The vehicle-grid coupling power flow model can be used to uniformly identify different abnormal operating conditions of the vehicle-grid coupling system, thereby improving the efficiency of identifying abnormal operating conditions of the vehicle-grid coupling system.

[0150] like Fig. 9 As shown, a device 900 for identifying abnormal operating conditions of a vehicle-grid coupling system is shown, and the details are as follows.

[0151] The electrical model building module 910 is configured to build an electrical model of the traction power supply system according to the short-circuit capacity of the external power grid in the power system and the first electrical parameter of the traction power supply system in the vehicle-grid coupling system.

[0152] The operation load simulation model building module 920 is configured to build operation load simulation models of various types of electric locomotives with different departure intervals according to the second electrical parameters of the electric locomotive operation in the vehicle-grid coupling system and the operation diagrams of the electric locomotive types at different departure intervals.

[0153] The vehicle-grid coupling power flow model determination module 930 is configured to couple the electrical model and the operating load simulation model to obtain a vehicle-grid coupling power flow model.

[0154] The abnormal operating condition identification module 940 is configured to solve the vehicle-grid coupling power flow model and determine the abnormal operating condition of the vehicle-grid coupling system based on the solution result.

[0155] Fig.10 The schematic diagram of the computer device provided in the embodiment of the present application, the device can be integrated into a terminal device or a chip of the terminal device, and the terminal can be a computing device with data processing function. The device includes: a processor 1001, a storage medium 1002 and a bus 1003.

[0156] The storage medium 1002 stores program instructions executable by the processor 1001. When the computer device 1000 is running, the processor 1001 communicates with the storage medium 1002 via the bus 1003. The processor 1001 executes the program instructions to perform the above method embodiment. The specific implementation method and technical effect are similar and will not be repeated here.

[0157] Optionally, the present invention also provides a program product, such as a computer-readable storage medium, comprising a program, which is used to execute the above method embodiment when executed by a processor.

[0158] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0159] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0160] The above integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium.

[0161] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for identifying abnormal operating conditions of a vehicle-grid coupling system, characterized in that: include: According to the short-circuit capacity of the external power grid in the power system and the first electrical parameter of the traction power supply system in the vehicle-grid coupling system, an electrical model of the traction power supply system is constructed, including: Determine the equivalent model of the traction transformer and the equivalent model of the traction network according to the first electrical parameter of the traction power supply system, the short-circuit capacity of the external power grid, and the third electrical parameter per unit length of the external power grid line; determine the impedance-admittance equivalent model of the traction network according to the line properties of the traction network; determine the electrical model of the traction power supply system according to the equivalent model of the traction transformer, the equivalent model of the traction network, and the impedance-admittance equivalent model of the traction network; wherein the first electrical parameter includes the connection angle of the traction transformer, the voltage and current of the primary side, and the voltage and current of the secondary side; According to the second electrical parameters of the electric locomotive in the vehicle-grid coupling system and the operation diagrams of the electric locomotive types at different departure intervals, the operation load simulation models of various types of electric locomotives at different departure intervals are constructed; The electrical model and the operating load simulation model are coupled to obtain a vehicle-grid coupled power flow model; The vehicle-grid coupling power flow model is solved, and the abnormal operating condition of the vehicle-grid coupling system is determined based on the solution result.

2. The method according to claim 1, characterized in that The determining, according to the first electrical parameter of the traction power supply system, the short-circuit capacity of the external power grid, and the third electrical parameter per unit length of the external power grid line, an equivalent model of the traction transformer and an equivalent model of the traction network comprises: Determining a conversion matrix corresponding to the first electrical parameters through a conversion formula between the first electrical parameters and a connection angle of the traction transformer; Determining the total impedance of the power system according to the voltage level of the external power grid and the short-circuit capacity; According to the total impedance of the power system, an equivalent model of the traction transformer and an equivalent model of the traction network are determined.

3. The method according to claim 1, characterized in that Determining the impedance-admittance equivalent model of the traction network according to the line attributes of the traction network includes: According to the line properties of the traction network and the fourth electrical parameter of the line unit length of the traction network, the impedance admittance equivalent model of the traction network at a preset frequency is determined; the impedance admittance equivalent model includes an impedance admittance matrix per unit length and a parallel impedance admittance matrix per unit length.

4. The method according to claim 1, characterized in that: The method of constructing operation load simulation models of various types of electric locomotives with different departure intervals according to the second electrical parameters of the electric locomotives in the vehicle-grid coupling system and the operation diagrams of the electric locomotive types at different departure intervals includes: Determine the second electrical parameter of the electric locomotive according to the force during the operation of the electric locomotive, and determine the second electrical parameter traction model of the electric locomotive according to the second electrical parameter; the second electrical parameter includes active power and reactive power; Determining the dimension of the electric locomotive data matrix and the elements of the electric locomotive data matrix according to the second electrical parameter traction model and the actual number of electric locomotives dispatched during the power flow calculation period; The actual number of electric locomotive departure intervals and the power flow calculation time period are determined according to the operation diagram of the electric locomotive, and operation load simulation models of various electric locomotives corresponding to different departure intervals are constructed in combination with the electric locomotive data matrix.

5. The method according to claim 1, characterized in that The solving of the vehicle-grid coupled power flow model includes: A preset algorithm is used to determine the fifth electrical parameter of each electrical node of the traction network, the voltage of each electric locomotive is iteratively solved, and the current is updated according to the voltage of the electric locomotive; The voltage of the electrical node is updated according to the current until the voltage of all electric locomotives meets a preset convergence condition.

6. The method according to claim 1, characterized in that The solving of the vehicle-grid coupled power flow model includes: Determine whether the voltage deviation in the power flow calculation time period is greater than a first preset threshold value based on the solution result, and if the voltage deviation is greater than the first preset threshold value, identify the voltage as an abnormal operating condition; Based on the solution result, it is determined whether the distortion rate of the harmonic voltage of the electrical node at the outlet of the traction substation is greater than a second preset threshold value. If the distortion rate of the harmonic voltage is greater than the second preset threshold value, the harmonic voltage is identified as an abnormal operating condition.

7. A device for identifying abnormal working conditions of a vehicle-grid coupling system, characterized in that: include: The electrical model building module is configured to build an electrical model of the traction power supply system according to the short-circuit capacity of the external power grid in the power system and the first electrical parameter of the traction power supply system in the vehicle-grid coupling system, including: Determine the equivalent model of the traction transformer and the equivalent model of the traction network according to the first electrical parameter of the traction power supply system, the short-circuit capacity of the external power grid, and the third electrical parameter per unit length of the external power grid line; determine the impedance-admittance equivalent model of the traction network according to the line properties of the traction network; determine the electrical model of the traction power supply system according to the equivalent model of the traction transformer, the equivalent model of the traction network, and the impedance-admittance equivalent model of the traction network; wherein the first electrical parameter includes the connection angle of the traction transformer, the voltage and current of the primary side, and the voltage and current of the secondary side; The operation load simulation model building module is configured to build operation load simulation models of multiple types of electric locomotives with different departure intervals according to the second electrical parameters of the electric locomotive operation in the vehicle-grid coupling system and the operation diagrams of the electric locomotive types at different departure intervals; A vehicle-grid coupled power flow model determination module is configured to couple the electrical model and the operating load simulation model to obtain a vehicle-grid coupled power flow model; The abnormal operating condition identification module is configured to solve the vehicle-grid coupling power flow model and determine the abnormal operating condition of the vehicle-grid coupling system based on the solution result.

8. A device for executing a method for identifying abnormal operating conditions of a vehicle-grid coupling system, characterized in that: include: processor; a memory for storing processor-executable instructions; When the processor executes the executable instructions, the method according to any one of claims 1 to 6 is implemented.

9. A non-volatile computer-readable storage medium, characterized in that: The device comprises a computer program or an instruction for storing the computer program or the instruction, which, when executed, enables the method according to any one of claims 1 to 6 to be implemented.

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