Train ground automatic crossover resistance fault detection method and system

Abstract

The application discloses a train ground automatic through-phase resistance fault detection method, and relates to the technical field of resistance fault detection. First, a neutral section resistance unit is formed, and the neutral section resistance unit is used as a conduction load of a train ground automatic through-phase system. Then, according to the working state of the ground automatic through-phase, in combination with real-time voltage of the neutral section resistance unit and real-time current flowing through the neutral section resistance unit, resistance faults are detected without blind spots, and the resistance fault types are distinguished. The method has good sensitivity and high reliability. The application further discloses a train ground automatic through-phase resistance fault detection system, which is beneficial to field operation and further guarantees the safety of control of the ground automatic through-phase and the traction power supply system.

Description

Technical Field

[0001] This invention relates to the technical field of resistance fault detection, and more specifically, to a method and system for automatic over-phase resistance fault detection on train ground. Background Technology

[0002] my country's electrified railways use a single-phase AC 27.5kV power supply system, which involves introducing 110kV or 220kV voltage from the power grid, then stepping it down to 27.5kV and transmitting it to the trains via the overhead contact line. However, single-phase traction loads on electrified railways generate significant negative-sequence currents on the three-phase power system side. The increase in negative-sequence currents can affect the normal operation of generators in power plants and reduce the transmission capacity of the power grid.

[0003] To address these issues, the current practice is to connect adjacent traction substations by switching phases. Since the power supply arms in different power supply sections have different phases, phase-separating insulators are required, thus creating electrical phase separation. This is because the unique single-phase power supply of electrified railways necessitates a neutral zone between two power supply arms for electrical isolation. Electrical phase separation is typically located at substation exits and at the junctions between different traction substations. Generally, there is an electrical phase separation every 20-30 km on domestic railways.

[0004] Currently, there are two main solutions for automatic phase-crossing: onboard and ground-based. With the onboard automatic phase-crossing solution, the train needs to disconnect the onboard circuit breaker in advance and coast through the neutral section, resulting in loss of traction and speed, especially on steep sections (e.g., gradients greater than 30%). Due to the significant loss of train power, the onboard automatic phase-crossing solution cannot effectively reduce travel time. The ground-based automatic phase-crossing solution supplies power to the neutral section through equipment installed on the ground. A phase-switching switch bridges the two power supply arms. While the train is running in the neutral section, the ground-based device controls the phase-switching switch to switch the power supply arms. No train operation is required; the entire process is automated by the ground-based automatic phase-crossing device. This reduces driver workload and fatigue, prevents driver error from causing the train to overshoot the neutral section while energized, and features short switching time, minimal train speed loss, and high safety and reliability. It is applicable to various types of trains for phase-crossing.

[0005] The circuit structure of the train's automatic phase-crossing system can be found in [reference]. Figure 1 ,exist Figure 1In this system, thyristor valves are used as phase-changing switches. The two power supply arms are designated as power supply arm A and power supply arm B. Sensors G1, G2, and G3 are located on the rails and are used to detect whether the train has arrived at its corresponding section. Neutral sections are installed between the contact wires of the two power supply arms. The neutral sections are electrically isolated from the two power supply arms using anchor joints JY1 and JY2 (to meet power supply and mechanical segmentation requirements, the contact wire is divided into several independent segments of a certain length; each segment is called an anchor segment, and the connection between two adjacent anchor segments is called an anchor joint). A phase-changing switch K1 and a phase-changing switch K2 are connected across anchor joints JY1 and JY2, respectively. The power supply to the neutral sections is provided by two... The switching of each phase switch is completed. The phase switches K1, K2 and the neutral section are connected in series with circuit breakers QF1, QF2 and QF3 for protection and isolation. The whole control process includes: (1) When no train passes, the neutral section is de-energized. When sensor G1 detects the arrival of the train, it controls the phase switch K1 to close and the power supply arm A supplies power to the neutral section; (2) When the train enters the neutral section and reaches sensor G2 and the whole train enters the neutral section, the phase switch K1 is opened and the phase switch K2 is closed and the power supply arm B supplies power to the neutral section; (3) When the train runs to sensor G3, the train enters the power supply area of ​​the power supply arm B, the phase switch K2 is opened, the neutral section is de-energized, and waits for the next train to enter.

[0006] The commutation switch uses a thyristor valve, which has a long service life and meets the reliability requirements of the aforementioned control process. The conduction condition of the thyristor valve requires not only a positive voltage but also that the anode current reaches or exceeds the minimum anode current required to maintain the on-state. For example... Figure 1 As shown, resistor R is used as the conducting load of the phase switching switch under no-load conditions. The resistor is an important component of the automatic phase switching system on the ground. Before the train enters the neutral section, the thyristor valve needs to be turned on in advance through the resistor to ensure that the two sides of the anchor joint JY1 or JY2 are at the same potential, thus avoiding arcing due to potential difference when the train enters the neutral section. Therefore, the resistor as the conducting load should be reliable and safe, and fault detection of the resistor is also crucial. At present, there is only a set value overcurrent protection for the resistor. It mainly relies on introducing a current transformer in the resistor branch to collect the real-time current and compare the real-time current with the fixed protection setting to realize resistor fault detection. However, there are two main problems, including: 1) The current in the resistor branch is related to the neutral voltage, and the neutral voltage fluctuates greatly (the neutral voltage fluctuates with the contact network voltage, with an allowable range of 17.5kV to 31.5kV). The fixed protection setting cannot maintain high sensitivity across the entire voltage range. 2) Although overcurrent protection can detect resistance short-circuit faults, it cannot detect open-circuit faults. Therefore, there are detection blind spots, which seriously affect the safety of the ground automatic phase-splitting system and traction power supply system. Summary of the Invention

[0007] To address the issues of low sensitivity and poor reliability in current ground-based resistance fault detection methods for train phase transitions, this invention proposes an automatic ground-based resistance fault detection method. Based on the operating status of the automatic ground-based phase transition, this method detects resistance faults without blind spots, and identifies the presence and type of faults in real time, exhibiting high sensitivity and reliability. Furthermore, this invention proposes an automatic ground-based resistance fault detection system, which facilitates on-site operation and further ensures the safety of the automatic ground-based phase transition control and traction power supply system.

[0008] The present invention aims to solve the above-mentioned technical problems to at least some extent.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] A method for automatic detection of over-phase resistance faults on the ground of a train, the method comprising the following steps:

[0011] S1: Connect n sub-resistors with the same resistance value in parallel to form a sub-resistor unit. Connect m sub-resistor units in series to form a neutral section resistor unit, which serves as the conducting load of the train ground automatic phase-crossing system.

[0012] S2: Collect the real-time voltage of the neutral section resistor unit and the real-time current flowing through the neutral section resistor unit;

[0013] S3: Determine whether the train automatic phase-crossing system is in working condition. If yes, activate the neutral section resistor unit fault detection and execute step S4; otherwise, lock the neutral section resistor unit fault detection.

[0014] S4: Compare and calculate using real-time voltage and real-time current, and determine whether the resistor has a fault and its type based on the calculation results.

[0015] Preferably, the rated resistance value corresponding to the neutral section resistor unit is:

[0016]

[0017] Among them, R z R1 represents the rated resistance value of the neutral section resistor unit, and R1 represents the rated resistance value of each sub-resistor in the sub-resistor unit.

[0018] Based on the above technical means, multiple sub-resistors with the same resistance value are connected in parallel to form a sub-resistor unit, and then connected in series, which improves the sensitivity of detection and the reliability of application.

[0019] Preferably, in step S2, the voltage transformer PT and the current transformer CT are used to collect the real-time voltage of the neutral section resistor unit and the real-time current flowing through the neutral section resistor unit, respectively.

[0020] Preferably, the lower limit value of the tripping of the ground automatic phase-splitting system grid voltage protection is set to U. min The upper limit value for the tripping of the ground automatic phase-break system grid voltage protection is U. max Let U be the real-time voltage of the neutral section resistor unit. If the real-time voltage U of the neutral section resistor unit satisfies:

[0021] U min ≤U≤U max

[0022] This indicates that the train's automatic phase-crossing system is in operation.

[0023] In the above technical solution, when the automatic phase-crossing system of the train is in working condition, fault signal output is allowed. If the automatic phase-crossing system of the train is not in working condition, the fault signal output is blocked. The determination that the automatic phase-crossing system of the train is in working condition is a prerequisite for resistance fault detection.

[0024] Preferably, if a short-circuit fault occurs in any resistor of one of the m sub-resistor units, then the resistance value R′ of the conducting load of the automatic phase-switching switch of the train ground after the short-circuit fault is... Z for:

[0025]

[0026] The resistance value R′ of the conducting load of the automatic phase-switching switch of the train's ground crossing system after a short-circuit fault. Z The resistance rating R of the neutral section resistor unit z The resistance change ΔR1 is as follows:

[0027] ΔR1 is less than 0. When a short-circuit fault occurs, the resistance value R′ of the conducting load of the automatic phase-switching switch of the train's ground-based phase-switching system after the short-circuit fault is less than 0. Z As it decreases, the absolute value of the change in resistance is

[0028] If any resistor in any of the m sub-resistor units experiences an open-circuit fault, then the resistance value R″ of the conducting load of the automatic phase-switching switch of the train ground system after the open-circuit fault will be... Z for:

[0029]

[0030] The resistance value R″ of the conducting load of the automatic phase-switching switch of the train's ground-based phase-switching system after an open-circuit fault. Z The resistance rating R of the neutral section resistor unit z The resistance change ΔR2 is:

[0031] ΔR2 is greater than 0. When an open-circuit fault occurs, the resistance value R″ of the conducting load of the automatic phase-switching switch of the train's ground-based phase-switching system after the open-circuit fault is... Z The value increases, and the absolute value of the resistance change is...

[0032] Preferably, in step S4, the comparison calculation using real-time voltage and real-time current is a resistance value comparison calculation. The process of determining the resistance fault type based on the calculation results is as follows:

[0033] Let I be the real-time current flowing through the neutral section resistor unit. Calculate the real-time resistance value R of the neutral section resistor unit based on the real-time voltage and real-time current. S The expression is:

[0034]

[0035] The real-time resistance value R of the neutral section resistor unit S With resistance rating R Z Comparison:

[0036] When R S <R Z Resistance change (R) S -R Z The absolute value of ) is ≥ X*R1 / n, where X represents the sensitivity coefficient, and the duration of the resistance change is ≥ the detection delay time T. SET When this happens, a short circuit fault occurs in the neutral section resistor unit;

[0037] When R S >R Z Resistance change (R) S -R Z The absolute value of ) is ≥ X*R1 / n(n-1), where X represents the sensitivity coefficient, and the duration of the resistance change is ≥ the detection delay time T. SET If this occurs, an open-circuit fault will occur in the neutral section resistor unit.

[0038] Based on the above technical means, the real-time resistance value of the neutral section resistor unit is calculated by the voltage of the neutral section resistor unit and the current flowing through the neutral section resistor unit, and compared with the rated resistance value in real time. It does not use a fixed protection setting current, and can maintain high sensitivity across the entire voltage range, thereby identifying the type of resistor fault. It has good sensitivity and high reliability.

[0039] Preferably, the conduction status of the phase switching switch in the automatic phase transition system is determined based on the status feedback contact of the phase switching switch in the automatic phase transition system, thereby determining the operating status of the automatic phase transition system.

[0040] Preferably, after determining the operating state of the automatic phase-crossing system on the ground, in step S4, the comparison calculation using real-time voltage and real-time current is a current value comparison calculation. Based on the calculation results, the process for determining the resistance fault type is as follows:

[0041] Calculate the current I that should flow through the neutral section resistor unit based on the real-time voltage U and the rated resistance value of the corresponding neutral section resistor unit. u The expression is:

[0042]

[0043] The current I that should flow through the neutral section resistor unit u Compare with real-time current I:

[0044] When I<X*I u X represents the sensitivity coefficient, and the current I u Duration ≥ Detection delay time T SET If this occurs, an open-circuit fault will occur in the neutral section resistor unit;

[0045] When I>X*I u X represents the sensitivity coefficient, and the current I u Duration ≥ Detection delay time T SET If this occurs, a short circuit fault will occur in the neutral section resistor unit.

[0046] Based on the above technical means, after determining the working status of the ground automatic phase-crossing system, the current that should flow through the neutral section resistor unit when no fault occurs is calculated by combining the real-time voltage U and the rated resistance value. Then, this current is compared with the collected real-time current. This is equivalent to using the current that should flow through the neutral section resistor unit when no fault occurs as the "changing" current protection setting value, which can maintain high sensitivity across the entire voltage range, thereby identifying the type of resistor fault. It has good sensitivity and high reliability.

[0047] Preferably, after a short circuit or open circuit fault occurs in the neutral section resistor unit, the train ground automatic phase-splitting system issues an alarm signal or activates the circuit breaker to trip.

[0048] This application also proposes a train ground automatic over-phase resistance fault detection system, comprising:

[0049] The neutral section resistor building unit is used to connect n sub-resistors with the same resistance value in parallel to form a sub-resistor unit. M sub-resistor units are connected in series to form a neutral section resistor unit, which serves as the conducting load of the train ground automatic phase-crossing system.

[0050] The voltage acquisition unit is used to acquire the real-time voltage of the neutral section resistor unit;

[0051] The current acquisition unit is used to acquire the real-time current flowing through the neutral section resistor unit;

[0052] The working status judgment unit is used to determine whether the automatic phase-crossing system of the train is in working status;

[0053] The resistance fault detection unit compares and calculates real-time voltage and real-time current when the train's automatic phase-crossing system is in operation, and determines the type of resistance fault based on the calculation results.

[0054] Compared with the prior art, the beneficial effects of the technical solution adopted in this invention are as follows:

[0055] This invention proposes a method for detecting automatic phase-crossing resistance faults on the ground of a train. First, a neutral section resistance unit is formed and used as the conducting load of the automatic phase-crossing system. Then, based on the operating state of the automatic phase-crossing system, combined with the real-time voltage and current flowing through the neutral section resistance unit, resistance faults are detected without blind spots, and the type of resistance fault is identified. This method exhibits high sensitivity and reliability. Furthermore, this invention proposes an automatic phase-crossing resistance fault detection system for trains, which facilitates on-site operation and further ensures the safety of the automatic phase-crossing control and traction power supply system. Attached Figure Description

[0056] Figure 1 This diagram shows the circuit structure of the current automatic phase-crossing system for trains as presented in the background section of this invention.

[0057] Figure 2 This is a flowchart illustrating the automatic over-phase resistance fault detection method for trains proposed in this embodiment of the invention.

[0058] Figure 3 This diagram illustrates the structure of the neutral segment resistor unit proposed in this embodiment of the invention.

[0059] Figure 4 This is a schematic diagram of the automatic over-phase resistance fault detection system for trains proposed in this embodiment of the invention.

[0060] Figure 5 This diagram illustrates the circuit structure of the automatic phase-crossing resistance fault detection system for train ground, as proposed in this embodiment of the invention. Detailed Implementation

[0061] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0062] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions.

[0063] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings;

[0064] The terms used to describe positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0065] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0066] Example 1

[0067] This embodiment proposes an automatic over-phase resistance fault detection method for train ground systems. A flowchart illustrating this method can be found here. Figure 2 In this method, the circuit diagram of the train ground automatic phase-crossing system is as follows: Figure 1 As shown, the automatic phase-separation system for trains uses thyristor valves as phase-switching switches. The two power supply arms are power supply arm A and power supply arm B. G1, G2, and G3 are sensors on the rails used to detect whether the train has reached its corresponding section. Neutral sections are installed at the contact wires of the two power supply arms. The neutral sections are electrically isolated from the two power supply arms using anchor joints JY1 and JY2, respectively. A phase-switching switch K1 and a phase-switching switch K2 are connected across anchor joints JY1 and JY2, respectively. The power supply to the neutral section is switched by the two phase-switching switches. Circuit breakers QF1, QF2, and QF3 are connected in series with the neutral section for protection and isolation, respectively. (See [reference]). Figure 1 Traditionally, a monolithic resistor R is used as the conducting load for the commutation switch. In this embodiment, the design has been improved to form a neutral section resistor unit, ultimately resulting in the following configuration: Figure 2 The flowchart of the automatic over-phase resistance fault detection method for train ground shown is available in [reference]. Figure 2 This includes the following steps:

[0068] S1: Connect n sub-resistors with the same resistance value in parallel to form a sub-resistor unit. Connect m sub-resistor units in series to form a neutral section resistor unit, which serves as the conducting load of the train ground automatic phase-crossing system.

[0069] S2: Collect the real-time voltage of the neutral section resistor unit and the real-time current flowing through the neutral section resistor unit;

[0070] S3: Determine whether the train automatic phase-crossing system is in working condition. If yes, activate the neutral section resistor unit fault detection and execute step S4; otherwise, lock the neutral section resistor unit fault detection.

[0071] S4: Compare and calculate using real-time voltage and real-time current, and determine whether the resistor has a fault and its type based on the calculation results.

[0072] In this embodiment, considering the problem of high resistance value and power consumption when the traditional neutral section resistor is directly connected to a 27.5kV supply voltage (e.g., with a conventional resistance value of 2-5 kΩ, the power consumption can reach 151kW-378kW at rated voltage), multiple sub-resistor units of the same specification are connected in series to form an "n parallel m series sub-resistor unit". Figure 3 As shown, multiple sub-resistors with the same resistance value are connected in parallel to form a sub-resistor unit, which is then connected in series. This distributes the high voltage and high power, improving the sensitivity of the detection and the reliability of the application. Based on the relationship between series and parallel resistances, the rated resistance value corresponding to the neutral section resistance unit is:

[0073]

[0074] Among them, R z R1 represents the rated resistance value of the neutral section resistor unit, and R1 represents the rated resistance value of each sub-resistor in the sub-resistor unit.

[0075] In step S2, the voltage transformer PT and the current transformer CT are used to collect the real-time voltage of the neutral section resistor unit and the real-time current flowing through the neutral section resistor unit, respectively.

[0076] Let the lower limit of the tripping value of the ground automatic phase-splitting system grid voltage protection be U. min The upper limit value for the tripping of the ground automatic phase-break system grid voltage protection is U. max Let U be the real-time voltage of the neutral section resistor unit. If the real-time voltage U of the neutral section resistor unit satisfies:

[0077] U min ≤U≤U max

[0078] That is, when the real-time voltage U of the neutral section resistor unit is within the allowable grid voltage fluctuation range of the traction power supply system, the automatic phase crossing system of the train is in working condition.

[0079] In this embodiment, when the automatic phase-crossing system is in working condition, fault signal output is allowed. If the automatic phase-crossing system is not in working condition, fault signal output is blocked. The determination that the automatic phase-crossing system is in working condition is a prerequisite for resistance fault detection, preventing false alarms when the automatic phase-crossing system is not in working condition.

[0080] In this embodiment, for Figure 3 For the neutral section resistor unit shown, if any resistor in any of the m sub-resistance units experiences a short-circuit fault, then the resistance value R′ of the conducting load of the automatic phase-switching switch of the train ground system after the short-circuit fault is... Z for:

[0081]

[0082] The resistance value R′ of the conducting load of the automatic phase-switching switch of the train's ground crossing system after a short-circuit fault. Z The resistance rating R of the neutral section resistor unit z The resistance change ΔR1 is as follows:

[0083] ΔR1 is less than 0. When a short-circuit fault occurs, the resistance value R′ of the conducting load of the automatic phase-switching switch of the train's ground-based phase-switching system after the short-circuit fault is less than 0. Z As it decreases, the absolute value of the change in resistance is

[0084] If any resistor in any of the m sub-resistor units experiences an open-circuit fault, then the resistance value R″ of the conducting load of the automatic phase-switching switch of the train ground system after the open-circuit fault will be... Z for:

[0085]

[0086] The resistance value R″ of the conducting load of the automatic phase-switching switch of the train's ground-based phase-switching system after an open-circuit fault. Z The resistance rating R of the neutral section resistor unit z The resistance change ΔR2 is:

[0087] ΔR2 is greater than 0. When an open-circuit fault occurs, the resistance value R″ of the conducting load of the automatic phase-switching switch of the train's ground-based phase-switching system after the open-circuit fault is... Z The value increases, and the absolute value of the resistance change is...

[0088] Based on the resistance value change patterns of the above-mentioned open-circuit and short-circuit faults, in step S4, the comparison calculation using real-time voltage and real-time current is a resistance value comparison calculation. The process of determining the type of resistance fault based on the calculation results is as follows:

[0089] Let I be the real-time current flowing through the neutral section resistor unit. Calculate the real-time resistance value R of the neutral section resistor unit based on the real-time voltage and real-time current. S The expression is:

[0090]

[0091] The real-time resistance value R of the neutral section resistor unit S With resistance rating R Z Comparison:

[0092] When R S <R Z Resistance change (R) S -R Z The absolute value of the resistance change is greater than or equal to X*R1 / n, where X represents the sensitivity coefficient (which can be set in practice, such as 0.8), and the duration of the resistance change is greater than or equal to the detection delay time T. SET (In specific implementation, it can be set, such as 10ms) when a short circuit fault occurs in the neutral section resistor unit;

[0093] When R S >R Z Resistance change (R) S -R Z The absolute value of the resistance change is greater than or equal to X*R1 / n(n-1), where X represents the sensitivity coefficient (which can be set in practice, such as 0.8), and the duration of the resistance change is greater than or equal to the detection delay time T. SET (In specific implementation, it can be set, such as 10ms) when the neutral section resistor unit experiences an open circuit fault.

[0094] By measuring the voltage and current flowing through the neutral section resistor unit, the real-time resistance value of the neutral section resistor unit is calculated and compared with the rated resistance value in real time. Without using a fixed protection setting current, it can maintain high sensitivity across the entire voltage range, thereby identifying the type of resistor fault. It has good sensitivity and high reliability.

[0095] Based on the above determination, after a short circuit or open circuit fault occurs in the neutral section resistor unit, the train ground automatic phase-separation system will issue an alarm signal or activate circuit breakers QF1, QF2 and QF3 to trip.

[0096] Example 2

[0097] The overall implementation process of this embodiment is basically the same as that of Embodiment 1. In this embodiment, the only difference is that when determining the working state of the automatic phase-crossing system, the conduction status of the phase-crossing switch in the automatic phase-crossing system is determined based on the state of the feedback contact of the phase-crossing switch in the automatic phase-crossing system, such as the direction of the contact, thereby determining the working state of the automatic phase-crossing system.

[0098] Example 3

[0099] This embodiment is basically the same as the implementation process of S1 to S3 mentioned in Embodiment 1. In this embodiment, after determining the working state of the automatic phase-crossing system, in step S4, the comparison calculation using real-time voltage and real-time current is a current value comparison calculation. Based on the calculation results, the process of determining the resistance fault type is as follows:

[0100] Calculate the current I that should flow through the neutral section resistor unit based on the real-time voltage U and the rated resistance value of the corresponding neutral section resistor unit. u The expression is:

[0101]

[0102] The current I that should flow through the neutral section resistor unit u Compare with real-time current I:

[0103] When I<X*I u X represents the sensitivity coefficient (which can be set in practice, such as 0.9), and the current I... u Duration ≥ Detection delay time T SET If this occurs, an open-circuit fault will occur in the neutral section resistor unit;

[0104] When I>X*I u X represents the sensitivity coefficient (which can be set in specific implementations, such as 1.1), and the current I... u Duration ≥ Detection delay time T SET If this occurs, a short circuit fault will occur in the neutral section resistor unit.

[0105] After determining the operating status of the automatic phase-crossing system, this embodiment calculates the current that the neutral section resistor unit should flow when no fault occurs, based on the real-time voltage U and the rated resistance value. Then, it compares this current with the collected real-time current. This is equivalent to using the current that the neutral section resistor unit should flow when no fault occurs as the "changing" current protection setting value, which can maintain high sensitivity across the entire voltage range, thereby identifying the type of resistor fault. It has good sensitivity and high reliability.

[0106] After a short circuit or open circuit fault occurs in the neutral section resistor unit, the train's ground automatic phase-separation system will issue an alarm signal or activate the circuit breaker to trip.

[0107] Example 4

[0108] like Figure 4 As shown, this embodiment proposes a train ground automatic over-phase resistance fault detection system. See [link to documentation]. Figure 4 The structural diagram shown includes:

[0109] The neutral section resistor building unit is used to connect n sub-resistors with the same resistance value in parallel to form a sub-resistor unit. M sub-resistor units are connected in series to form a neutral section resistor unit, which serves as the conducting load of the train ground automatic phase-crossing system.

[0110] The voltage acquisition unit is used to acquire the real-time voltage of the neutral section resistor unit;

[0111] The current acquisition unit is used to acquire the real-time current flowing through the neutral section resistor unit;

[0112] The working status judgment unit is used to determine whether the automatic phase-crossing system of the train is in working status;

[0113] The resistance fault detection unit compares and calculates real-time voltage and real-time current when the train's automatic phase-crossing system is in operation, and determines the type of resistance fault based on the calculation results.

[0114] In the train ground automatic over-phase resistance fault detection system proposed in this embodiment, the voltage acquisition unit uses a voltage transformer (PT), the current acquisition unit uses a current transformer (CT), and a neutral section resistance construction unit is used to construct the following... Figure 3 The neutral section resistor unit structure shown is applied as a whole. Figure 1 The circuit structure of the train ground automatic phase-crossing system shown can be found in [reference]. Figure 5 ,exist Figure 5 In this circuit, the neutral section resistor unit, voltage transformer (PT), and current transformer (CT) are high-voltage devices, while the resistor fault detection unit is a low-voltage device. The voltage and current signals collected by the voltage transformer (PT) and current transformer (CT) are converted from analog to digital and input to the resistor fault detection unit. The resistor fault detection unit determines the type of resistor fault based on the calculation results.

[0115] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for automatically detecting over-phase resistance faults on the ground of a train, characterized in that, The method includes the following steps: S1: Connect n sub-resistors with the same resistance value in parallel to form a sub-resistor unit. Connect m sub-resistor units in series to form a neutral section resistor unit, which serves as the conducting load of the train ground automatic phase-crossing system. S2: Collect the real-time voltage of the neutral section resistor unit and the real-time current flowing through the neutral section resistor unit; S3: Determine whether the train automatic phase-crossing system is in working condition. If yes, activate the neutral section resistor unit fault detection and execute step S4; otherwise, lock the neutral section resistor unit fault detection. S4: Compare and calculate using real-time voltage and real-time current, and determine whether the resistor has a fault and its type based on the calculation results.

2. The automatic over-phase resistance fault detection method for trains according to claim 1, characterized in that, The rated resistance value corresponding to the neutral section resistor unit is: Among them, R z R1 represents the rated resistance value of the neutral section resistor unit, and R1 represents the rated resistance value of each sub-resistor in the sub-resistor unit.

3. The automatic over-phase resistance fault detection method for train ground as described in claim 2, characterized in that, In step S2, the voltage transformer PT and the current transformer CT are used to collect the real-time voltage of the neutral section resistor unit and the real-time current flowing through the neutral section resistor unit, respectively.

4. The automatic over-phase resistance fault detection method for train ground as described in claim 3, characterized in that, Let the lower limit of the tripping value of the ground automatic phase-splitting system grid voltage protection be U. min The upper limit value for the tripping of the ground automatic phase-break system grid voltage protection is U. max Let U be the real-time voltage of the neutral section resistor unit. If the real-time voltage U of the neutral section resistor unit satisfies: IN min ≤U≤U max Then the train's automatic phase-crossing system is in operation.

5. The automatic over-phase resistance fault detection method for train ground as described in claim 4, characterized in that, If a short-circuit fault occurs in any resistor of any of the m sub-resistor units, then the resistance value R′ of the conducting load of the automatic phase-switching switch of the train ground system after the short-circuit fault will be... Z for: The resistance value R′ of the conducting load of the automatic phase-switching switch of the train's ground crossing system after a short-circuit fault. Z The resistance rating R of the neutral section resistor unit z The resistance change ΔR1 is as follows: ΔR1 is less than 0. When a short-circuit fault occurs, the resistance value R′ of the conducting load of the automatic phase-switching switch of the train's ground-based phase-switching system after the short-circuit fault is less than 0. Z As it decreases, the absolute value of the change in resistance is If any resistor in any of the m sub-resistor units experiences an open-circuit fault, then the resistance value R″ of the conducting load of the automatic phase-switching switch of the train ground system after the open-circuit fault will be... Z for: The resistance value R″ of the conducting load of the automatic phase-switching switch of the train's ground-based phase-switching system after an open-circuit fault. Z The resistance rating R of the neutral section resistor unit z The resistance change ΔR2 is: ΔR2 is greater than 0. When an open-circuit fault occurs, the resistance value R″ of the conducting load of the automatic phase-switching switch of the train's ground-based phase-switching system after the open-circuit fault is... Z The value increases, and the absolute value of the resistance change is...

6. The automatic over-phase resistance fault detection method for train ground as described in claim 5, characterized in that, In step S4, the comparison calculation using real-time voltage and real-time current is a resistance value comparison calculation. Based on the calculation results, the process of determining the resistance fault type is as follows: Let I be the real-time current flowing through the neutral section resistor unit. Calculate the real-time resistance value R of the neutral section resistor unit based on the real-time voltage and real-time current. S The expression is: The real-time resistance value R of the neutral section resistor unit S With resistance rating R Z Comparison: When R S <R Z Resistance change (R) S -R Z The absolute value of ) is ≥ X*R1 / n, where X represents the sensitivity coefficient, and the duration of the resistance change is ≥ the detection delay time T. SET When this happens, a short circuit fault occurs in the neutral section resistor unit; When R S >R Z Resistance change (R) S -R Z The absolute value of ) is ≥ X*R1 / n(n-1), where X represents the sensitivity coefficient, and the duration of the resistance change is ≥ the detection delay time T. SET If this occurs, an open-circuit fault will occur in the neutral section resistor unit.

7. The automatic over-phase resistance fault detection method for train ground as described in claim 3, characterized in that, The on / off status of the phase switching switch in the automatic phase transition system is determined by the status feedback contact of the phase switching switch, thereby determining the operating status of the automatic phase transition system.

8. The automatic over-phase resistance fault detection method for train ground as described in claim 4 or 7, characterized in that, After determining the operating status of the automatic phase-crossing system on the ground, in step S4, the comparison calculation using real-time voltage and real-time current is a current value comparison calculation. Based on the calculation results, the process of determining the resistance fault type is as follows: Calculate the current I that should flow through the neutral section resistor unit based on the real-time voltage U and the rated resistance value of the corresponding neutral section resistor unit. u The expression is: The current I that should flow through the neutral section resistor unit u Compare with real-time current I: When I<X*I u X represents the sensitivity coefficient, and the current I u Duration ≥ Detection delay time T SET If this occurs, an open-circuit fault will occur in the neutral section resistor unit; When I>X*I u X represents the sensitivity coefficient, and the current I u Duration ≥ Detection delay time T SET If this occurs, a short circuit fault will occur in the neutral section resistor unit.

9. The automatic over-phase resistance fault detection method for train ground as described in claim 8, characterized in that, After a short circuit or open circuit fault occurs in the neutral section resistor unit, the train's ground automatic phase-separation system will issue an alarm signal or activate the circuit breaker to trip.

10. A train ground automatic over-phase resistance fault detection system, characterized in that, include: The neutral section resistor building unit is used to connect n sub-resistors with the same resistance value in parallel to form a sub-resistor unit. M sub-resistor units are connected in series to form a neutral section resistor unit, which serves as the conducting load of the train ground automatic phase-crossing system. The voltage acquisition unit is used to acquire the real-time voltage of the neutral section resistor unit; The current acquisition unit is used to acquire the real-time current flowing through the neutral section resistor unit; The working status judgment unit is used to determine whether the automatic phase-crossing system of the train is in working status; The resistance fault detection unit compares and calculates real-time voltage and real-time current when the train's automatic phase-crossing system is in operation, and determines the type of resistance fault based on the calculation results.

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