Method and apparatus for creating equivalent circuit models

Abstract

To enable the creation of appropriate equivalent circuit models for track circuits, taking frequency characteristics into consideration. [Solution] The rail resistance component and rail inductance component are formed by an RL ladder circuit 10 consisting of N stages (N≧3) of series-parallel circuits in which resistance elements Rn are connected in series and inductance elements Ln are connected in parallel. A combination of frequencies of signals flowing through the rails, including track circuit signals, is selected from combinations of signals to be simulated according to the simulation application. Based on the combination to be simulated, the number of stages N is determined, and the parameters of resistance Rn and inductance Ln for each of the N stages are set to create an equivalent circuit model of the rails that constitute the track circuit.

Description

Technical Field

[0003]

[0001] The present invention relates to a method for creating an equivalent circuit model and the like.

Background Art

[0002] As an equivalent circuit model for analyzing and simulating the electrical properties of a track circuit, a method is known in which the rail portion of the track circuit is modeled as a four-terminal distributed constant circuit composed of a rail resistance R, a rail inductance L, a leakage conductance G between rails, and a capacitance C, which are called the primary constants of the track circuit (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, there has been a problem that it is not easy to perform a simulation in which an actual track circuit is simulated using the above equivalent circuit model.

[0005] In other words, the rail portion of a track circuit may carry multiple frequency signals, including track circuit signals for train detection, return current, ATC signals, and track circuit signals for level crossing control. The equivalent circuit model described above, which is a distributed-parameter circuit, is a linear circuit, so it is possible to simulate multiple frequency signals using the superposition principle. The primary constants of a track circuit have frequency characteristics, and in particular, the frequency characteristics of the rail impedance, namely the rail resistance R and rail inductance L, greatly affect the behavior of the track circuit. Therefore, when simulating multiple frequency signals, it might seem that one could determine the parameters of the circuit elements based on the primary constants of the track circuit at each frequency and then combine the simulation results using the superposition principle, but it is not that simple.

[0006] Magnetic saturation in transformers such as impedance bonds, and contact between wheels and rails with rust present, can cause distortion of the signal waveform accompanied by increases and decreases in harmonics. This indicates that nonlinearity is occurring in the track circuit, and simulations based on the superposition principle, which assumes linearity, have difficulty reproducing such signal waveform distortion. Furthermore, for the purpose of simulation, such as estimating the failure factors and locations of track circuits, it is desirable to be able to simulate the frequency characteristics of the first-order constants of the track circuit and perform transient analysis.

[0007] The problem that this invention aims to solve is to enable the appropriate creation of an equivalent circuit model of the rails of a track circuit that simulates frequency characteristics. [Means for solving the problem]

[0008] The first invention for solving the above problem is: A method for creating an equivalent circuit model for creating an equivalent circuit model of rails that constitute a track circuit, The rail resistance component and rail inductance component are formed by one of the following circuits (hereinafter collectively referred to as "RL network circuits"): 1) an RL ladder circuit consisting of N stages (N≧3) of series-parallel circuits with resistors connected in series and inductances connected in parallel; 2) an RL series-parallel circuit consisting of N stages (N≧3) of series-connected small circuits: a first stage with resistors and inductances connected in series, and subsequent stages with resistors and inductances connected in parallel; and 3) a circuit in which part or all of the RL ladder circuit or the RL series-parallel circuit is replaced with a dual circuit. Setting the parameters of the resistance and inductance for each of the N stages, This is a method for creating an equivalent circuit model that includes [the specified element].

[0009] Other inventions include, An equivalent circuit model creation device for creating an equivalent circuit model of rails that constitute a track circuit, Regarding the rail resistance component and rail inductance component, the RL network circuit forming means is formed by any of the following circuits (hereinafter collectively referred to as "RL network circuits"): 1) an RL ladder circuit consisting of N stages (N≧3) of series-parallel circuits in which resistors are connected in series and inductances are connected in parallel; 2) an RL series-parallel circuit in which a first-stage small circuit in which resistors and inductances are connected in series and a second and subsequent small circuits in which resistors and inductances are connected in parallel are connected in N stages (N≧3) in series; and 3) a circuit in which part or all of the RL ladder circuit or the RL series-parallel circuit is replaced with a dual circuit. A parameter setting means for setting the parameters of the resistance and inductance of each of the N stages, An equivalent circuit model creation device equipped with the following may be configured.

[0010] According to the first invention, etc., by forming rail resistance and rail inductance with an RL network circuit consisting of multiple (N stages) resistors and inductors, it becomes possible to appropriately create an equivalent circuit model of the rails of a track circuit that simulates the frequency characteristics of rail resistance and rail inductance.

[0011] The second invention is, in the above invention, Select a combination of frequencies for simulation from among the combinations of signals flowing through the rail, including track circuit signals, which are determined according to the simulation application. Based on the aforementioned combination of simulation targets, N is determined, This is a method for creating an equivalent circuit model that further includes the following.

[0012] It is generally believed that the greater the number of stages N in an RL network circuit, the greater the ability to reproduce the electrical characteristics, including the frequency characteristics of the track circuit. However, a large number of stages N leads to a more complex circuit configuration in the equivalent circuit model, resulting in disadvantages such as increased processing load and compromised processing stability in simulations using this model. Furthermore, the appropriate number of stages N, considering these advantages and disadvantages, may vary depending on the combination of signal frequencies flowing through the rail portion of the track circuit. Therefore, as in the second invention, it is possible to appropriately determine the number of stages N in the RL network circuit based on the combination of signal frequencies to be simulated.

[0013] The third invention is, in the above invention, Setting the aforementioned parameters means The initial values ​​based on the rail type are provisionally set for the parameters, The parameters that were provisionally set are corrected based on the difference between the measured signal frequency components obtained by decomposing the measured signal flowing through the rail into frequency components, and the signal frequency components obtained by simulating the RL network circuit based on the provisional settings. including, This is a method for creating an equivalent circuit model.

[0014] Since the track circuit varies in length, equipment configuration, and surrounding environment for each facility, even if the same combination of frequency signals is passed through, the actually measured signals can differ. Therefore, as in the third invention, first, an initial value based on the type of rail is tentatively set, and the RL network circuit based on the tentative setting is simulated to obtain the signal frequency components. Then, based on the difference between the obtained signal frequency components and the measured signal frequency components obtained by decomposing the measured signal into frequency components, the parameters tentatively set are corrected, making it possible to appropriately set the parameters of the resistance and inductance of the RL network circuit.

Brief Description of Drawings

[0015] [Figure 1] Equivalent circuit of the rail of the track circuit. [Figure 2] Equivalent circuit of the rail of the track circuit. [Figure 3] Flowchart of the equivalent circuit model creation process. [Figure 4] An example of the stage number determination table. [Figure 5] Explanation diagram of the parameter setting of the elements of the RL ladder circuit. [Figure 6] Functional configuration example of the equivalent circuit model creation device. [Figure 7] Examination results for the estimation results of the parameters of the elements of the RL ladder circuit. [Figure 8] Estimation results of the parameters of the elements of the RL ladder circuit. [Figure 9] Estimation results of the parameters of the elements of the RL ladder circuit. [Figure 10] Estimation results of the parameters of the elements of the RL ladder circuit. [Figure 11] Estimation results of the parameters of the elements of the RL ladder circuit. [Figure 12] Estimation results of the parameters of the elements of the RL ladder circuit. [Figure 13] Estimation results of the parameters of the elements of the RL ladder circuit. [Figure 14] Estimation results of the parameters of the elements of the RL ladder circuit. [Figure 15]Estimation results of the element parameters of the RL ladder circuit. [Figure 16] Estimation results of the element parameters of the RL ladder circuit. [Figure 17] Estimation results of the element parameters of the RL ladder circuit. [Figure 18] Estimation results of the element parameters of the RL ladder circuit. [Figure 19] Estimation results of the element parameters of the RL ladder circuit. [Figure 20] Other circuit examples of RL network circuits. [Figure 21] Other circuit examples of RL network circuits. [Modes for carrying out the invention]

[0016] Preferred embodiments of the present invention will be described below with reference to the drawings. However, the applicable forms of the present invention are not limited to the following embodiments. Furthermore, in the drawings, the same elements are denoted by the same reference numerals.

[0017] This embodiment relates to a technique for creating an equivalent circuit model of the rails constituting a track circuit in order to analyze and simulate the electrical properties of the track circuit.

[0018] Figure 1 shows the equivalent circuit of the rails constituting the track circuit in this embodiment. As shown in Figure 1, in this embodiment, the equivalent circuit of the rails constituting the track circuit is represented as a four-terminal circuit consisting of an RL ladder circuit 10, leakage conductance G between rails, and capacitance C. The RL ladder circuit 10 is an example of an RL network circuit and is an N-stage (N≧3) series-parallel circuit in which resistive elements Rn (n=1,2,··,N) are connected in series and inductance elements Ln (n=1,2,··,N) are connected in parallel.

[0019] As shown in Figure 2, the rail portion of the track circuit can be modeled as an equivalent circuit of a distributed constant circuit consisting of rail resistance R, rail inductance L, leakage conductance G between rails, and capacitance C per unit length, which are called the first-order constants of the track circuit. The equivalent circuit of this embodiment shown in Figure 1 is a circuit in which the rail impedance, which is the rail resistance R and rail inductance L, is replaced with an RL ladder circuit 10 in this equivalent circuit of the rail portion.

[0020] Rail impedance, consisting of rail resistance R and rail inductance L, has frequency characteristics. In this embodiment, the equivalent circuit of the rail simulates these frequency characteristics by replacing the rail resistance R and rail inductance L with the RL ladder circuit 10. In addition, various frequency signals may flow through the track circuit, such as track circuit signals for train detection, return current, ATC signals, and track circuit signals for level crossing control. Therefore, by configuring the RL ladder circuit 10 according to the simulation application, such as which frequency signals flow through the track circuit to be simulated, an equivalent circuit model of the rail useful for specific applications can be created.

[0021] Figure 3 is a flowchart illustrating the flow of the equivalent circuit model creation process for creating an equivalent circuit model of the rails.

[0022] As shown in Figure 3, first, a combination of signal frequencies f(f1~fm) to be simulated is selected (Step S1). This signal frequency f can include not only the fundamental wave but also its harmonics (especially the 3rd and 5th harmonics). Next, the number of stages N of the RL ladder circuit 10 is determined by referring to the stage determination table 310 and based on the selected combination of signal frequencies f(f1~fm) (Step S3).

[0023] Figure 4 shows an example of the stage number determination table 310. As shown in Figure 4, the stage number determination table 310 associates the simulation application with the recommended number of stages for the RL ladder circuit 10. The method for determining this association in the stage number determination table 310 will be described later.

[0024] The simulation application indicates the type of track circuit whose signal frequencies are to be simulated, corresponding to the combination of signal frequencies flowing through the track circuit. Figure 4 defines three types of simulation applications: "All Frequency Band," which covers track circuits where signals of any frequency can flow; "Commercial + Level Crossing," which covers commercial track circuits in non-electrified or AC-electrified sections with level crossings, where commercial frequency (50Hz / 60Hz) track circuit signals and level crossing controller signals (several kHz to tens of kHz) flow; and "DC + Commercial," which covers commercial track circuits in DC-electrified sections, where return current (0Hz) and commercial frequency (50Hz / 60Hz) track circuit signals flow. Of course, the combinations of signals flowing through the track circuit are not limited to these.

[0025] The recommended number of stages is the minimum number of stages necessary to simulate the rail impedance at each signal frequency corresponding to the simulation application. The number of stages N in the RL ladder circuit 10 is determined so as to be greater than or equal to this recommended number of stages.

[0026] After determining the number of stages N in the RL ladder circuit 10, the parameters of the resistive element Rn and inductance element Ln, which are elements of the RL ladder circuit 10, are then set. Actual track circuits are exposed to the outdoor environment and affected by weather conditions such as rainfall, as well as by the track bed and surrounding structures, so the electrical properties may differ for each piece of equipment. To reflect the different electrical properties of each track circuit, the parameters of the elements of the RL ladder circuit 10 are set using measured signals, which are signals actually measured for the track circuit.

[0027] Figure 5 illustrates the setting of the element parameters of the RL ladder circuit 10. Actual measured signals are acquired and prepared in advance when a combination of frequency signals f(f1~fm) corresponding to the simulation application is applied to the rails of the target track circuit. These measured signals can be measurable voltages or currents. Then, frequency analysis is performed on these measured signals to decompose them into frequency signals f(f1~fm) corresponding to the simulation application, and signal waveforms for each frequency signal f(f1~fm) are obtained (step S5). In Figure 5, the frequency decomposition of a certain frequency signal into three signal waveforms: the fundamental wave, the third harmonic, and the fifth harmonic is shown.

[0028] Furthermore, the parameters of the resistive element Rn and inductance element Ln, which are elements of each of the N stages of the RL ladder circuit 10 in the equivalent circuit of the rails of the target track circuit, are provisionally set based on the type of rails related to the target track circuit (step S7).

[0029] Next, a simulation signal is obtained (step S9) from the simulation, which involves applying a composite signal of frequency signals f(f1~fm) corresponding to the simulation purpose to the equivalent circuit of the entire track circuit, including the equivalent circuit of the rail with provisionally set parameters. Then, a frequency analysis is performed on the obtained simulation signal to decompose it into signals for each signal frequency f(f1~fm) corresponding to the simulation purpose (frequency decomposition) (step S11). In Figure 5, the frequency decomposition is performed into three signal waveforms: the fundamental wave, the third harmonic, and the fifth harmonic, similar to the measured signal.

[0030] Next, for each frequency f(f1~fm), the signal waveforms of the measured signal and the simulated signal are compared, and the parameters of the elements of the RL ladder circuit 10 are modified so that the difference between them is minimized (step S13). For example, the parameters of the RL ladder circuit 10 are modified so that the difference between the amplitude and phase of the signal waveforms is minimized.

[0031] Furthermore, the process of reacquiring the simulation signal and comparing it with the measured signal to further correct the parameters of the elements of the modified RL ladder circuit 10 (steps S9 to S13) may be repeated until the difference between the simulation signal and the measured signal satisfies the conditions.

[0032] Because the frequency of the signal flowing through the rails is biased towards a specific frequency band, setting parameters based on the frequency signal corresponding to the simulation application makes it possible to form an RL ladder circuit 10 that simulates the frequency characteristics of the rail impedance with fewer stages N.

[0033] Figure 6 shows an example of the functional configuration of the equivalent circuit model creation device 1. According to Figure 6, the equivalent circuit model creation device 1 is configured with an operation unit 102, a display unit 104, a communication unit 106, a processing unit 200, and a storage unit 300, and is realized as a type of computer system. The equivalent circuit model creation device 1 may be realized with a single computer, or it may be configured by connecting multiple computers.

[0034] The operation unit 102 is implemented by an input device such as a keyboard, mouse, touch panel, or various switches, and outputs an operation signal to the processing unit 200 according to the operation performed. The display unit 104 is implemented by a display device such as a liquid crystal display or touch panel, and displays various information based on the display signal from the processing unit 200. The communication unit 106 is a communication device implemented by a wireless communication module, router, modem, jack or control circuit for wired communication cables, etc., and connects to a given communication network to perform data communication with external devices.

[0035] The processing unit 200 is a processor implemented using arithmetic devices and circuits such as a CPU (Central Processing Unit) or FPGA (Field Programmable Gate Array), and it performs overall control of the equivalent circuit model creation device 1 based on programs and data stored in the memory unit 300, input data from the operation unit 102 and the communication unit 106, etc.

[0036] Furthermore, the processing unit 200 executes the equivalent circuit model creation program 302 to perform equivalent circuit model creation processing (see Figure 3) for creating equivalent circuit models of the rails that constitute the track circuit. Functional processing blocks for this purpose include a circuit formation unit 202, a stage number determination unit 204, and a parameter setting unit 206. Each of these functional units in the processing unit 200 can be implemented either through software execution by the processing unit 200 or through dedicated calculation circuits. In this embodiment, the former, software implementation, will be described.

[0037] The circuit formation unit 202 forms the rail resistance component R and rail inductance component L of the track circuit using an RL ladder circuit 10 consisting of N stages (N≧3) of series-parallel circuits in which resistive elements Rn are connected in series and inductance elements Ln are connected in parallel (see Figure 1).

[0038] The stage number determination unit 204 selects a combination of frequencies of signals flowing through the rails, including track circuit signals, which are determined according to the simulation application, and determines the number of stages N of the RL ladder circuit 10 based on the selected combination of simulation targets.

[0039] Specifically, by referring to the stage number determination table 310 (see Figure 4), the number of stages N is determined to be equal to or greater than the recommended number of stages corresponding to the simulation application that corresponds to the combination of signal frequencies to be simulated.

[0040] The parameter setting unit 206 sets the parameters for each of the N stages of the RL ladder circuit 10, specifically for the resistor Rn and inductance Ln. That is, it provisionally sets initial values ​​based on the rail type as parameters, and then corrects the provisionally set parameters based on the difference between the measured signal frequency components obtained by decomposing the measured signal flowing through the rail into frequency components, and the signal frequency components obtained by simulating the RL ladder circuit 10 based on the provisional settings (see Figure 5).

[0041] The memory unit 300 can be implemented using integrated circuit (IC) memory such as ROM (Read Only Memory) or RAM (Random Access Memory), storage devices such as hard disks, or external storage devices built in a cloud environment. The memory unit 300 stores programs and data for the processing unit 200 to comprehensively control the equivalent circuit model creation device 1. The memory unit 300 is also used as a workspace for the processing unit 200, temporarily storing calculation results performed by the processing unit 200, as well as input data from the operation unit 102 and the communication unit 106.

[0042] In this embodiment, the storage unit 300 stores an equivalent circuit model creation program 302, a stage number determination table 310, and equivalent circuit model data 320. The equivalent circuit model data 320 is data relating to the equivalent circuit model of the created rail, and includes the number of stages N of the RL ladder circuit 10, the parameters of its resistive element Rn and inductance element Ln, as well as parameters of the first-order constants of the track circuit, such as leakage conductance G and capacitance C.

[0043] Here, we will explain in detail how the stage number determination table 310 was set. The stage number determination table 310 was set by estimating the parameters of the elements Rn and Ln (n=1,2,··,N) of the RL ladder circuit 10 for each simulation application and examining their validity.

[0044] Specifically, for each of the three simulation applications (combinations of signal frequencies) defined in the stage number determination table 310, equivalent circuit models of track circuits with RL ladder circuits 10 having a number of stages N ranging from N=2 to 5 were formed. For each of these equivalent circuit models with different numbers of stages N, the parameters of the elements of the RL ladder circuit 10 were estimated, and their validity was examined.

[0045] Specifically, a track circuit with known linear constants was prepared as the subject of study, and the parameters of the elements of the RL ladder circuit 10 included in the equivalent circuit model of the rail portion were estimated for this subject track circuit. Then, the frequency characteristics of the impedance Z of the RL ladder circuit 10 (more specifically, the absolute value of impedance Z |Z| and the impedance angle ∠Z) obtained from the estimated parameters were determined. The accuracy of the estimated parameters was examined by comparing this with the rail impedance (absolute value of impedance and impedance angle) at each signal frequency f(f1~fm) corresponding to the simulation application, which can be obtained from the known linear constants. In other words, the reproducibility of the rail impedance at signal frequencies f(f1~fm) corresponding to the simulation application was examined.

[0046] Figure 7 summarizes the results of the study. As shown in Figure 7, the simulation applications are the same as the stage determination table 310 shown in Figure 4: "all frequency band", "commercial + level crossing", and "DC + commercial". The target frequency is the frequency used as a comparison target for impedance Z in order to examine the accuracy of the parameters, and is the signal frequency f(f1~fm) determined according to the simulation application. Note that 50Hz in "commercial + level crossing" and "DC + commercial" assumes the frequency of the track circuit signal at commercial frequency, and 150Hz assumes its third harmonic. In addition, 10kHz in "commercial + level crossing" assumes the signal of the level crossing controller, and 0Hz in "DC + commercial" assumes the return current.

[0047] The practicality of the number of stages N was determined from the parameter estimation results. In Figure 7, circles (〇) indicate high frequency accuracy at the target frequency and thus practicality, while triangles (△) and crosses (×) indicate decreasing accuracy. The number of stages N that was judged to be practical was set as the recommended number of stages in the stage number determination table 310.

[0048] Figures 8 to 19 show examples of estimated parameter results for elements of the RL ladder circuit 10 for each combination of simulation application and the number of stages N of the RL ladder circuit. Figures 8 to 11 show examples of estimated results when the simulation application is "all frequency band" and the number of stages N of the RL ladder circuit 10 is 5, 4, 3, and 2, respectively. Figures 12 to 15 show examples of estimated results when the simulation application is "commercial + railroad crossing" and the number of stages N of the RL ladder circuit 10 is 5, 4, 3, and 2, respectively. Figures 16 to 19 show examples of estimated results when the simulation application is "DC + commercial" and the number of stages N of the RL ladder circuit 10 is 5, 4, 3, and 2, respectively.

[0049] In Figures 8 to 19, the left side shows the frequency characteristics of the absolute value |Z| of impedance Z obtained from the estimated parameters, and the center shows the frequency characteristics of the impedance angle ∠Z. In all figures, the horizontal axis is frequency [Hz], and the vertical axis is the absolute value |Z| [Ω / km] or impedance angle ∠Z [rad]. The solid line represents the frequency characteristics based on the estimated parameters, and the plotted points are the values ​​(correct values) of the absolute value |Z| of impedance Z or impedance angle ∠Z at the target frequency based on a first-order constant. The right side shows the estimated parameter values ​​(per 1km of one rail out of the left and right rails).

[0050] In Figures 8 to 19, if a solid line passes through or near a plotted point, it indicates that the frequency characteristics based on the estimated parameters approximate the true values, i.e., the estimation accuracy is good. According to Figures 8 to 19, in all simulation applications, a larger number of stages N tends to result in the frequency characteristics based on the estimated parameters approximating the true values ​​and thus improving the estimation accuracy.

[0051] According to this embodiment, by forming the rail resistance R and rail inductance L with an RL ladder circuit 10 consisting of multiple stages (N stages) of resistive elements Rn and inductance elements Ln, it becomes possible to appropriately create an equivalent circuit model of the rails of a track circuit that simulates the frequency characteristics of the rail resistance R and rail inductance L.

[0052] It should be noted that the applicable embodiments of the present invention are not limited to those described above, and can be modified as appropriate without departing from the spirit of the invention.

[0053] (A) RL Ladder Circuit In the above embodiment, the rail resistance R and rail inductance L of the rail portion, which are the primary constants of the track circuit, were aggregated into an equivalent circuit model for the round trip of the left and right rails. This is because, under normal conditions, the voltage between the left and right rails is important, while the potential to ground is not, and the magnitude of the track circuit signal current flowing through the left and right rails can be considered the same (balanced).

[0054] However, in the event of an abnormality such as a ground fault, the magnitude of the current flowing through the left and right rails may differ (unbalanced current). Therefore, as shown in Figure 20, an equivalent circuit model of the rail portion of the track circuit may be created by individually replacing the rail resistance R and rail inductance L in the left and right rails with RL ladder circuits 10a. The number of stages N in the RL ladder circuits 10a corresponding to each rail may be the same or different. Furthermore, the rail impedance of the RL ladder circuit 10a corresponding to each rail is ideally half (1 / 2) of the impedance Z of the RL ladder circuit 10 formed by combining the impedances of both the left and right rails.

[0055] (B) RL Network Circuit In the above embodiment, the RL network circuit was defined as an RL ladder circuit 10. However, as shown in Figure 21, an RL series-parallel circuit 12 may also be defined, which consists of a first-stage small circuit in which a resistive element and an inductive element are connected in series, and subsequent small circuits in which a resistor and an inductor are connected in parallel, with N stages connected in series.

[0056] Furthermore, the circuit may be one in which part or all of the RL ladder circuit 10 or the RL series-parallel circuit 12 is replaced with a dual circuit.

[0057] (C) Modeling of equivalent circuits Furthermore, although the equivalent circuit model of the rails in the above-described embodiment is defined as a distributed-parameter circuit for generality, it may also be approximated by discretizing it to an appropriate length and cascading lumped-parameter circuits. [Explanation of symbols]

[0058] 1... Equivalent circuit model creation device 200... Processing Unit 202...Circuit forming part 204... Step number determination unit 206...Parameter setting section 300...Storage section 302... Equivalent Circuit Model Creation Program 310... Table for determining the number of steps 320... Equivalent circuit model data 10...RL Ladder Circuit

Claims

1. A method for creating an equivalent circuit model for creating an equivalent circuit model of rails that constitute a track circuit, The rail resistance component and rail inductance component shall be formed by one of the following circuits (hereinafter collectively referred to as "RL network circuit"): 1) an RL ladder circuit consisting of N stages (N≧3) of series-parallel circuits in which resistors are connected in series and inductances are connected in parallel; 2) an RL series-parallel circuit in which a first-stage small circuit in which resistors and inductances are connected in series and subsequent small circuits in which resistors and inductances are connected in parallel are connected in N stages (N≧3) in series; and 3) a circuit in which part or all of the RL ladder circuit or the RL series-parallel circuit is replaced with a dual circuit. Setting the parameters of the resistance and inductance for each of the N stages, A method for creating an equivalent circuit model that includes this.

2. Select a combination of frequencies for simulation from among the combinations of signals flowing through the rail, including track circuit signals, which are determined according to the simulation application. Based on the aforementioned combination of simulation targets, N is determined, The method for creating an equivalent circuit model according to claim 1, further comprising:

3. Setting the aforementioned parameters means The initial values ​​based on the rail type are provisionally set for the parameters, The parameters are corrected based on the difference between the measured signal frequency components obtained by decomposing the measured signal flowing through the rail into frequency components, and the signal frequency components obtained by simulating the RL network circuit based on the provisional settings. including, A method for creating an equivalent circuit model according to claim 1 or 2.

4. An equivalent circuit model creation device for creating an equivalent circuit model of rails that constitute a track circuit, Regarding the rail resistance component and rail inductance component, the RL network circuit forming means is formed by any of the following circuits (hereinafter collectively referred to as "RL network circuits"): 1) an RL ladder circuit consisting of N stages (N≧3) of series-parallel circuits in which resistors are connected in series and inductances are connected in parallel; 2) an RL series-parallel circuit in which a first-stage small circuit in which resistors and inductances are connected in series and a second and subsequent small circuits in which resistors and inductances are connected in parallel are connected in N stages (N≧3) in series; and 3) a circuit in which part or all of the RL ladder circuit or the RL series-parallel circuit is replaced with a dual circuit. A parameter setting means for setting the parameters of the resistance and inductance of each of the N stages, An equivalent circuit model creation device equipped with the following features.

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