Microprocessor-based control system for electric heating of turnouts

Abstract

FIELD: railway transport.SUBSTANCE: invention relates in particular to automation and telemechanics systems designed to control track infrastructure facilities. The essence of the invention is that in the control system for electric heating of turnouts, containing cabinets, sensors and an automated workstation, the electric heating control cabinet additionally contains power isolating transformers for galvanic isolation of the power supply circuits of the electric heating elements. The communication cabinet provides the ability to set different temperature thresholds for modes with and without precipitation, as well as the heating time after precipitation has ceased. In addition, the system ensures blocking of remote control from the workstation when manual mode is activated on the control cabinet.EFFECT: increased operational safety of railway infrastructure and the reliability of turnouts due to the implementation of fault-tolerant control of the heating process with a diagnostic function.5 cl, 1 dwg

Description

[0001] Field of invention

[0002] The invention relates to the field of railway transport, in particular to automation and telemechanics systems designed to control track infrastructure facilities.

[0003] Background of the invention

[0004] Turnout electric heating systems are designed to ensure the trouble-free and safe operation of railway switches during the winter by removing snow and ice. The use of electric heating systems minimizes manual labor for turnout cleaning, significantly improving the safety of maintenance personnel and the reliability of the entire track infrastructure. Modern electric heating control systems widely utilize microprocessor controllers and various sensors (e.g., temperature, precipitation) to automate the process and improve its efficiency. Such systems are typically connected to automated workstations (AWP) and technical diagnostics and monitoring systems for remote monitoring and control.

[0005] The control system for electric heating of turnouts, known from the document [CN115551127A, publication date: 30.12.2022], is selected as a prototype. The known system comprises a communication cabinet equipped with the equipment necessary to ensure communication with the electric heating control cabinets at the station and the node of the data transmission network for general technological purposes of the infrastructure, as well as an automated workstation (AWP), and at least one electric heating control cabinet connected to the electric heating elements installed on the turnout, and configured to automatically control the heating based on data from rail temperature sensors, ambient air temperature and precipitation, with the ability to automatically diagnose the state of the electric heating elements and the circuits supplying them, as well as collect and transmit diagnostic information to the AWP.

[0006] The disadvantage of the prototype is the low safety of the railway infrastructure operation and the reliability of the switches, which, in turn, leads to a number of significant shortcomings, including:

[0007] —inefficient energy use and a high risk of delayed heating activation, as the control algorithm does not flexibly adapt to actual weather conditions, such as the presence or absence of precipitation. For example, the use of uniform, averaged response thresholds leads to excessive operation of the electric heating elements during periods without precipitation and, conversely, to delayed heating activation during heavy snowfall, which reduces the overall reliability of the turnout.

[0008] — High risk of freezing of the moving parts of the switch after snowfall, as the heating is turned off immediately after precipitation ceases, without taking into account residual moisture on the structural elements. This leads to the formation of ice when the temperature subsequently drops, blocking the switch or frog, and, as a result, to switch failures and disruptions to train schedules.

[0009] —high risk of high voltage from the power grid entering low-voltage track circuits due to the lack of galvanic isolation between the heating element power circuits and the power grid. This creates a risk of disrupting the proper operation of adjacent railway automation and telemetry systems, particularly signaling and interlocking systems, which reduces the safety of train operations.

[0010] —There is a high risk of life and health hazard to maintenance personnel when working directly on the switch, as there is no guaranteed way to block remote control commands when switching to manual control mode from the local control panel. This creates a dangerous situation in which a remote operator could mistakenly apply voltage to the heating elements while an electrician is on the switch, potentially resulting in serious injury to maintenance personnel from electric shock.

[0011] Thus, the technical problem that the invention is aimed at solving is the need to eliminate the existing shortcomings of the prototype.

[0012] Disclosure of the essence of the invention

[0013] The technical result that the invention is aimed at achieving is to increase the safety of the operation of railway infrastructure and the reliability of the operation of turnouts by implementing fault-tolerant control of the turnout heating process with a diagnostic function.

[0014] The essence of the invention is as follows.

[0015] A microprocessor-based control system for electric heating of turnouts, comprising a communication cabinet equipped with the equipment necessary to ensure communication with the electric heating control cabinets at the station and the node of the data transmission network for general technological purposes of the infrastructure, as well as an automated workstation (AWS), and at least one electric heating control cabinet connected to the electric heating elements installed on the turnout and configured to automatically control the heating based on data from sensors for rail temperature, ambient air temperature and precipitation, with the ability to automatically diagnose the state of the electric heating elements and the circuits supplying them, as well as collect and transmit diagnostic information to the AWS. Unlike the prototype:

[0016] – the electric heating control cabinet contains power isolating transformers for galvanic isolation of the power supply circuits of the electric heating elements from the power supply network;

[0017] – the communication cabinet is designed with the ability to set temperature thresholds for switching on and off the heating of the switch using a rail temperature sensor and / or an air temperature sensor separately for modes without precipitation and with precipitation, as well as with the ability to set the time for heating the switch after precipitation has ceased;

[0018] – the system ensures that the remote control option from the workstation is blocked when switching to manual control mode from the panel on the electric heating control cabinet.

[0019] The electric heating element heats the structural components of the turnout to remove snow and ice. The electric heating element is installed on the turnout, particularly on its moving parts, such as the switch blades and stock rails. Heating prevents the formation of ice, ensuring the smooth movement of the moving parts of the turnout, thereby increasing the safety of railway infrastructure and the reliability of the turnouts. The electric heating element can be implemented as a strip, ring, or other heating element. Preferably, the electric heating element can be implemented as a tubular electric heater (TEH), including one with a flat oval cross-section.

[0020] The rail temperature sensor, ambient temperature sensor, and precipitation sensor collect data on current weather conditions and the status of the heating system. These sensors are located on the monitored track section and connected to the electric heating control cabinet to transmit measured parameters to the system. Providing accurate temperature and precipitation information allows the controller to make decisions about whether to turn the heating on or off, thereby improving the safety of railway infrastructure and the reliability of turnouts by implementing fail-safe heating control with diagnostics. The sensors can be implemented as specialized industrial measuring devices: the temperature sensor as a resistance temperature transducer, and the precipitation sensor using optical, capacitive, or conductometric measurement principles.

[0021] The communications cabinet provides centralized control, data collection and processing, and interaction with external systems. The communications cabinet is equipped with the necessary hardware for communication with the station's electric heating control cabinets and the infrastructure's general-purpose data transmission network node. The system includes an automated workstation (AWS), which can be structurally or functionally integrated with the communications cabinet. The communications cabinet is designed to set temperature thresholds for turnout heating activation and deactivation based on a rail temperature sensor and / or an air temperature sensor, separately for both dry and wet conditions. It also allows for setting the turnout heating reheating time after precipitation has ceased.Implementing this control algorithm ensures an optimal heating mode based on actual weather conditions, preventing both excessive energy consumption and untimely system activation. This contributes to improved railway infrastructure safety and turnout reliability through fault-tolerant heating control with diagnostics. The communications cabinet can be implemented as an industrial cabinet containing a programmable logic controller (PLC) or industrial computer, communications modules, and power supply units.

[0022] The electric heating control cabinet provides direct control of the electric heating element power circuits and local data collection. The electric heating control cabinet is connected to the electric heating elements and is designed to automatically control heating based on data from rail temperature, ambient temperature, and precipitation sensors. It also provides automatic diagnostics of the electric heating element and its power supply circuits, as well as the collection and transmission of diagnostic information to the workstation. To enhance safety, the electric heating control cabinet includes power isolation transformers for galvanic isolation of the electric heating element power circuits from the power grid.Automatic diagnostics enable early detection of faults, and galvanic isolation eliminates the risk of hazardous voltage entering track circuits. This, combined, protects equipment and associated systems, thereby improving the safety of railway infrastructure and the reliability of turnouts through the implementation of fail-safe heating control with diagnostics. The electric heating control cabinet can be implemented as an outdoor metal cabinet containing power switching devices, a microprocessor controller, and power isolation transformers.

[0023] The system disables remote control from the workstation when switching to manual control from the panel on the electric heating control cabinet. This function can be implemented at the controller logic level and / or in hardware. Ensuring priority of local control over remote control prevents erroneous voltage supply by a remote operator during on-site work, protecting personnel and thereby improving the safety of railway infrastructure and the reliability of turnouts by implementing fail-safe heating process control with diagnostics. This lock can be implemented by setting the appropriate status flag in the controller when activating the local control panel, or by hardware, using a switch that physically interrupts the remote command reception circuit.

[0024] Additionally, the system can provide heating control in three modes: automatic, based on information from the aforementioned sensors and preset algorithms; remote, via operator commands from the workstation; and manual, from the control panel directly on the heating control cabinet. Multiple control modes provide flexibility in operating the system in various scenarios, from routine automatic operation to manual intervention in emergency situations. This enhances the safety of railway infrastructure and the reliability of turnouts by implementing fail-safe heating control with diagnostics. These modes are implemented in the system's controllers and are selected by the user through the corresponding interfaces.

[0025] To detect a decrease in insulation resistance, the electric heating control cabinet may preferably include an insulation resistance monitoring module. This module is installed in the control cabinet and connected to the heating element power feeders. The insulation resistance monitoring module can be configured to automatically disconnect the feeder power when the insulation resistance drops below 220 kOhm for no more than 0.3 seconds. Fast, automatic shutdown of the faulty circuit prevents current leakage-related emergencies, protecting equipment and personnel. This improves the safety of railway infrastructure operations and the reliability of turnouts by implementing fail-safe heating control with diagnostics.The insulation resistance monitoring module can be implemented as a specialized electronic device (insulation monitoring relay) integrated into the overall control and protection system.

[0026] Additionally, the communication cabinet can set winter / summer modes; set heating activation modes: based on rail temperature sensors and / or air temperature sensors, or heating in continuous mode; and turn on and off sockets for connecting hand tools located in the electric heating control cabinets. Setting the "winter" mode activates the heating control logic in accordance with the selected automatic, remote, or manual mode, while setting the "summer" mode deactivates the heating function to prevent energy consumption during the warm season. Additional functionality allows for optimization of the system depending on the season and specific operational tasks, thereby increasing the safety of railway infrastructure and the reliability of turnouts through the implementation of fault-tolerant heating process control with diagnostics.These functions are implemented in the communication cabinet controller and are configured through the automated workstation.

[0027] The invention is characterized by a previously unknown set of essential features from the prior art, characterized in that:

[0028] – the electric heating control cabinet contains power isolating transformers for galvanic isolation of the power supply circuits of the electric heating elements from the power supply network, which prevents the ingress of hazardous potential from the power network into low-voltage track circuits, thereby preventing disruption to the operation of adjacent railway automation and telemechanics systems;

[0029] – the communication cabinet is designed with the ability to set temperature thresholds for switching on and off the switch heating using a rail temperature sensor and / or an air temperature sensor separately for modes without precipitation and with precipitation, as well as with the ability to set the time for reheating the switches after precipitation has ceased, which makes it possible to adapt the heating control process to actual weather conditions, optimizing energy consumption and guaranteeing timely switching on and sufficient operating time of the heating to prevent icing;

[0030] – the system ensures that the remote control option from the automated workstation is blocked when switching to manual control mode from the panel on the electric heating control cabinet, which eliminates the conflict between remote and local control commands, ensuring the priority of the actions of personnel located directly at the equipment and protecting them from erroneous remote voltage supply.

[0031] The combination of the invention's essential features simultaneously eliminates the ingress of hazardous potential into track circuits, adapts the heating control process to actual weather conditions, and prioritizes the actions of personnel located directly at the equipment. This combination, in which reliable and fail-safe operation, ensured by an adaptive algorithm, is implemented within a system with built-in safety loops guaranteed by power galvanic isolation and protective interlocking, ensures the technical result of increased operational safety of railway infrastructure and the reliability of turnouts through the implementation of fail-safe heating control with diagnostic functionality.

[0032] The invention has a set of essential features previously unknown in the prior art, which indicates its compliance with the patentability criterion of “novelty”.

[0033] The invention is unknown in the prior art and does not clearly follow from it. Therefore, the invention meets the patentability criterion of "inventive step."

[0034] Implementation of the invention

[0035] The invention is explained by the following materials.

[0036] Fig. 1 – Functional diagram of the microprocessor control system for electric heating of turnouts.

[0037] To illustrate the possibility of implementation and a more complete understanding of the essence of the invention, an embodiment of it is presented below, which can be changed or supplemented in any way, while the present invention is in no way limited to the presented embodiment.

[0038] The microprocessor-based control system for electric heating of turnouts (SUESM), in accordance with Fig. 1, comprises a communication cabinet 10 and at least one electric heating control cabinet 12.

[0039] The electric heating control cabinet 12 is connected to the electric heating elements 14 installed on the turnout.

[0040] To collect information about the environmental conditions and the state of the object, the system also includes a rail temperature sensor16, an ambient air temperature sensor18, and a precipitation sensor20, connected to an electric heating control cabinet12.

[0041] The communication cabinet is equipped with the necessary equipment to communicate with the station's electric heating control cabinets and the infrastructure's general-purpose data transmission network node. The communication cabinet can set turnout heating on / off temperature thresholds using the rail temperature sensor and / or the air temperature sensor separately for precipitation-free and precipitation-intensive modes. It can also set the turnout heating reheating time after precipitation has ceased. Furthermore, the communication cabinet can set winter / summer modes and heating activation modes: using the rail temperature sensor and / or the air temperature sensor, or heating in continuous mode.

[0042] The system also includes an automated workstation (AWS) 22, linked to a communication cabinet 10. Furthermore, the electric heating control cabinet 12 is capable of collecting and transmitting diagnostic information to the AWS 22.

[0043] The electric heating control cabinet 12 is designed to automatically control the heating based on data from the rail temperature sensor 16, ambient air temperature sensor 18, and precipitation sensor 20, as well as to automatically diagnose the status of the electric heating elements 14 and their power supply circuits. To ensure safety, the electric heating control cabinet 12 contains power isolation transformers 24 for galvanic isolation of the power supply circuits of the electric heating elements 14 from the power supply network.

[0044] Furthermore, to detect a decrease in insulation resistance, the electric heating control cabinet 12 contains an insulation resistance monitoring module 26. The insulation resistance monitoring module 26 is configured to automatically disconnect the feeder power supply if the insulation resistance drops below 220 kOhm for a period not exceeding 0.3 seconds.

[0045] Also in the electric heating control cabinets 12 there are sockets 28 for connecting hand tools, while the communication cabinet 10 ensures their switching on and off.

[0046] The system provides heating control in three modes: automatic, based on information from the aforementioned sensors 16, 18, and 20 and preset algorithms; remote, based on operator commands from the ARM22; and manual, from the control panel directly on the heating control cabinet 12. The system also disables remote control from the ARM22 when switching to manual control from the panel on the electric heating control cabinet 12.

[0047] The invention works as follows.

[0048] In its initial state, the microprocessor-based switch heating control system (SMHCS) is in continuous monitoring mode. Rail temperature sensors 16, ambient air temperature sensor 18, and precipitation sensor 20 continuously measure environmental parameters and transmit data to the corresponding heating control cabinets 12. These cabinets 12, in turn, collect and preliminarily process this information, as well as their own diagnostic data, and transmit it to the communication cabinet 10, from where it is displayed on the automated workstation (AWS) 22.

[0049] The heating control system operates in one of three modes.

[0050] In automatic mode, which is the primary mode, the control process is initiated by the system's internal logic. Control cabinet 12 continuously compares data received from sensors 16, 18, and 20 with the setpoints (thresholds) set by the operator via ARM22 or directly from communication cabinet 10. The decision-making process depends on the presence of precipitation detected by sensor 20. If there is no precipitation, cabinet 12 compares the current temperature with the threshold set for "no precipitation" mode. If the temperature drops below this threshold, cabinet 12 turns on the heating, supplying power to the electric heating elements 14. When precipitation appears, the system switches to a second, separate threshold, set for "with precipitation" mode, and turns on the heating when it is reached.This dual-threshold algorithm allows for energy savings in clear weather, while also enabling a more proactive and intensive heating during snowfall, thereby preventing ice buildup. Once the precipitation sensor no longer detects precipitation, the system does not immediately shut off the heating, but activates a "reheating" timer for a period also preset via the communication cabinet. This ensures complete evaporation of moisture and drying of the turnout, preventing it from freezing when the temperature subsequently drops. This combination of features, adaptive thresholds, and the reheating function ensures fault tolerance and increases the reliability of turnouts.

[0051] In remote mode, control is initiated by the operator from ARM22. A command (e.g., to force heating on or off, switch to winter / summer mode, or turn on sockets28) is sent to the communication cabinet10, which transmits it to one or more control cabinets12 for execution.

[0052] In manual mode, control is performed by maintenance personnel directly on-site, from the control panel of cabinet 12. When switching to manual mode, the system disables remote control from ARM 22. This ensures that no remote command can interfere with the actions of the specialist operating the equipment, directly enhancing operational safety.

[0053] Safety is also enhanced by the fact that power to the electric heating elements is always supplied through power isolation transformers, which ensure continuous galvanic isolation of the power circuits from the power grid and track circuits. At the same time, the insulation resistance monitoring module continuously monitors the circuits. If the insulation resistance drops below 220 kOhm, the module automatically disconnects power to the faulty feeder within 0.3 seconds, preventing an emergency.

[0054] Furthermore, increased reliability is ensured by the continuous automatic diagnostics function. Cabinet 12 monitors the status of the electric heating elements 14 and their power supply circuits (e.g., by current consumption) and, if a pre-failure condition is detected, transmits diagnostic information to ARM22. This allows maintenance personnel to proactively troubleshoot the problem, without waiting for a complete system failure, for example, during heavy snowfall.

[0055] This ensures the achievement of a technical result consisting in increasing the safety of the operation of railway infrastructure and the reliability of the operation of turnouts due to the implementation of fault-tolerant control of the heating process with a diagnostic function.

Claims

1. A microprocessor-based control system for electric heating of turnouts, comprising a communication cabinet equipped with the equipment necessary to ensure communication with the electric heating control cabinets at the station and the node of the data transmission network for general technological purposes of the infrastructure, as well as an automated workstation (AWS) and at least one electric heating control cabinet connected to electric heating elements installed on the turnout and configured to automatically control the heating based on data from sensors for rail temperature, ambient air temperature and precipitation, with the ability to automatically diagnose the state of the electric heating elements and the circuits supplying them, as well as collect and transmit diagnostic information to the AWS, characterized in that: the electric heating control cabinet contains power isolating transformers for galvanic isolation of the power supply circuits of the electric heating elements from the power supply network; the communication cabinet is designed with the ability to set temperature thresholds for switching on and off the heating of the switch according to the rail temperature sensor and / or the air temperature sensor separately for the modes without precipitation and in the presence of precipitation, as well as with the ability to set the time for heating the switch after the end of precipitation; At the same time, the system ensures that the possibility of remote control from the automated workstation is blocked when switching to manual control mode from the panel on the electric heating control cabinet.

2. The system according to paragraph 1, characterized in that it provides the ability to control heating in three modes: automatically based on information from the mentioned sensors and specified algorithms; remotely by operator commands from automated workstation; manually from the control panel directly on the heating control cabinet.

3. The system according to paragraph 1, characterized in that, in order to detect a decrease in insulation resistance, the electric heating control cabinet contains an insulation resistance monitoring module.

4. The system according to paragraph 3, characterized in that the insulation resistance monitoring module is designed with the ability to automatically disconnect the feeder power supply when the insulation resistance drops below 220 kOhm for a time not exceeding 0.3 s.

5. The system according to paragraph 1, characterized in that the communication cabinet provides: setting the heating activation modes: according to the rail temperature sensors and / or the air temperature sensor, or heating in constant mode; switching on and off sockets for connecting hand tools located in electric heating control cabinets.

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