Monitoring and Protection Module for DC Double-Side Power Supply Tripping Link in Urban Rail Transit

Abstract

The present invention relates to a monitoring and protection module for the DC bilateral power supply inter-trip loop in urban rail transit, which includes a power supply module and a microprocessor. The power supply module includes an opto-isolated signal sampling input unit. The microprocessor includes a monitoring and processing unit, an action signal output terminal, a first strobe pulse output terminal, a second strobe pulse output terminal and a reset unit, and also includes an output signal opto-isolation unit. The microprocessor can monitor and control the situation of each inter-trip loop of the station. When the voltage duration exceeds the preset value, the fault indicator light flashes, the inter-trip loop is disconnected, and an alarm signal is issued. If there are abnormal electrified situations such as poor contact of loop contacts, jitter of relay contacts, condensation, adhesion through excessive resistance, etc., the alarm indicator light flashes, and at the same time the relay is disconnected, the inter-trip loop is disconnected, and an alarm signal is issued. Different fault causes can be distinguished and monitored, taking precautions to ensure that operating trains will no longer suddenly stop during operation due to secondary circuit faults.

Description

Technical Field

[0001] The present invention relates to the technical field of DC power supply for intelligent urban rail transit, and particularly to a monitoring and protection module for the DC bilateral power supply inter-trip loop in urban rail transit. Background Art

[0002] In the aspect of train traction power supply for urban rail transit, to ensure the safe operation of trains, the system widely adopts a DC bilateral power supply mode in the main power supply loop. The greatest advantage of this mode is that the power supply voltage at each point along the line is relatively stable, and the adjacent power supply devices on the same power supply arm can supply power to this power supply arm simultaneously or be used as backups for each other. That is, when a power supply substation fails and cannot supply power externally, the system can automatically cut off the power supply devices outside the faulty substation, disconnect the faulty devices of the faulty substation from the line, and at the same time, switch on the "sectionalizing switch" to connect this power supply arm to the power supply arm of the adjacent substation of the faulty substation, realizing the so-called "large bilateral power supply" to maintain the bilateral power supply in this section.

[0003] To prevent the occurrence of ground faults in the power supply arm, a bilateral inter-trip protection function is specially set in the power supply protection. Currently, the "secondary signal direct connection type" is widely adopted for the bilateral inter-trip signal transmission mode. That is, an inter-trip cable is used between stations N + 1, N, and N - 1. The comprehensive protection device at the sending end decides whether to send an inter-trip signal according to the fault type, and then forms an inter-trip loop through the sending relay, isolation relay, inter-trip cable, receiving relay and driving circuit breaker trip relay, and the main circuit breaker. The comprehensive protection device at the receiving end collects the inter-trip signal and starts / locks the receiving end to execute the line test function according to the nature of the inter-trip signal. When it is determined that it is an instantaneous line fault, the bilateral power supply devices start the reclosing to restore the bilateral power supply mode; otherwise, the line power supply is locked.

[0004] Since most urban rail transits are built underground in the city, that is, the so-called subway. Considering that the underground environment is different from the ground, with high humidity, when the locomotive runs, the dust blown by the air flow (wind force) mixed with the tiny metal salts generated by the friction between the wheels and the rails floats and is attached to the surface and inside of the electrical equipment under the action of the electric field force of the charged equipment, which is extremely likely to cause the failure of the existing functions of the equipment. In terms of the inter-trip loop, it can cause misoperation or refusal to operate of the controlled equipment, seriously threatening the safe operation of the locomotive.

[0005] In order to prevent all equipment in the DC traction system from malfunctioning or refusing to operate, the power supply maintenance departments still use the regular maintenance and testing, daily manual on-site inspection mode. Although this mode can detect and prevent potential problems in the equipment in advance, it cannot warn and respond to sudden failures inside the equipment and avoid power supply accidents caused by the failures in time, especially the double-side trip circuit. Because the secondary control signal transmission path of this circuit has many contacts and long lines, and some equipment is installed in the high-voltage area close to the ground (the lower part of the circuit breaker trolley), it is difficult to warn and respond to sudden failures inside the equipment and avoid power supply accidents caused by the failures in time by relying solely on the above-mentioned regular maintenance and testing, and daily manual on-site inspection mode.

[0006] Therefore, it is urgent to provide a "device" that can monitor and automatically temporarily release abnormal bilateral joint jumping actions at all times. Summary of the invention

[0007] The purpose of the present invention is to provide a monitoring and protection module for a DC bilateral power supply inter-trip circuit of an urban rail transit, which can comprehensively monitor and control the conditions of each inter-trip circuit of the station at all times.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] The present invention provides a monitoring and protection module for a DC bilateral power supply inter-trip circuit of urban rail transit, and the monitoring and protection module for a DC bilateral power supply inter-trip circuit of urban rail transit is characterized in that it comprises a power supply module and a microprocessor, wherein the power supply module comprises a working power supply, a power switch and a multi-channel optocoupler isolation signal sampling input unit, the microprocessor comprises a monitoring and processing unit, an action signal output terminal, a first strobe pulse output terminal, a second strobe pulse output terminal and a reset unit, and further comprises an output signal optocoupler isolation unit;

[0010] The multiple optical coupling isolation signal sampling input units are respectively coupled to the output ends of the interlocking circuits, and each of the interlocking circuits includes a normally closed relay;

[0011] The microprocessor is configured to receive signals from the multiple optocoupler isolation signal sampling input units and to feed back signals to the action signal output terminal, the first strobe pulse output terminal, and the second strobe pulse output terminal accordingly; when the judgment unit receives a signal from any optocoupler isolation signal sampling input unit for a continuous duration that is not less than a preset value, the microprocessor outputs a signal to the action signal output terminal and the first strobe pulse output terminal; when the judgment unit receives a signal from any optocoupler isolation signal sampling input unit for a positive pulse that is within a preset value and greater than 10 mS in width, and the number of pulses is not less than 2, the microprocessor outputs a signal to the second strobe pulse output terminal;

[0012] The first strobe pulse output end is coupled with a fault indicator light;

[0013] The action signal output terminal and the second stroboscopic output terminal are coupled to the action input terminal of the output signal opto-isolation unit. The action output terminal of the output signal opto-isolation unit is connected to the driving unit. The output terminal of the driving unit is electrically connected to the normally closed relay coil. The output terminal of the driving unit is also electrically connected to the control relay coil. The output terminal of the control relay is electrically connected to the signal transmitter;

[0014] The second stroboscopic pulse output terminal is also connected to the stroboscopic input terminal of the output signal opto-isolation unit. The stroboscopic pulse output terminal of the driving unit is connected to the abnormal warning light;

[0015] The reset unit includes a resistance reset button. The output terminal of the reset button is connected to the signal input terminal of the microprocessor.

[0016] Preferably, an action indicator light is provided on each of the normally closed relays.

[0017] Preferably, it further includes a binary DIP switch. The output terminal of the binary DIP switch is connected to the signal input terminal of the microprocessor and is used to form the preset value.

[0018] Preferably, the operation status output terminal of the microprocessor is further coupled with an operation indicator light.

[0019] Preferably, both the first stroboscopic pulse output terminal and the second stroboscopic pulse output terminal output stroboscopic pulses with a frequency of 1S and a duty cycle of 50%.

[0020] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0021] In the present invention, it is to fill the gap in the monitoring and protection functions of the existing DC double-sided power supply interlocking trip circuit in urban rail transit. Through the opto-isolation signal sampling input unit, it can comprehensively and real-time monitor and control the situation of each interlocking trip circuit of the station. When the voltage duration of the interlocking trip circuit exceeds the preset value, it is determined that a fault has occurred in the line. At this time, the warning indicator light flashes, the interlocking trip circuit is disconnected, and a warning signal is issued. Once the action is issued or the action is taken, it will be maintained all the time (it cannot be automatically restored). To restore the above action to the state before the action, it is necessary to manually process all the faults on-site and then press the reset button for 2S to restore to the previous state. If abnormal live conditions such as poor contact of the loop contact point, jitter of the relay contact, condensation, and adhesion of the over-resistance occur, the warning indicator light will flash, and at the same time, the relay will act, the interlocking trip circuit will be disconnected, and a warning signal will be issued. The present invention can distinguish and monitor different fault reasons, provide ideas for problem handling to quickly restore the train, prevent problems before they occur, and ensure that the operating train will no longer suddenly stop during operation due to faults in the interlocking secondary circuit. Description of the Drawings

[0022] Some specific embodiments of the present invention will be described in detail hereinafter with reference to the accompanying drawings in an illustrative rather than restrictive manner. The same reference numerals in the drawings denote the same or similar components or parts. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0023] Figure 1 is a principle block diagram of an embodiment of the present invention;

[0024] Figure 2 is a circuit diagram of the working power supply and the microprocessor of an embodiment of the present invention;

[0025] Figure 3 is a circuit diagram of the driving unit, the output signal opto-isolation unit and the multi-channel relay of an embodiment of the present invention.

[0026] Among them, the reference numerals are explained as follows:

[0027] 1. Working power supply and power switch; 11. Operation indicator light; 12. Fault indicator light;

[0028] 2. Opto-isolation signal sampling input unit;

[0029] 3. Microprocessor;

[0030] 4. Output signal opto-isolation unit;

[0031] 5. Driving unit;

[0032] 6. Reset button;

[0033] 7. Binary DIP switch;

[0034] 8. Microprocessor in-circuit programming interface;

[0035] 9. External function expansion serial interface;

[0036] 101. Normally closed relay; 102. Control relay. Detailed implementation manners

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0039] As Figure 1 shown, it includes a power supply module, a microprocessor 3, an output signal opto-isolation unit 4, and a multi-channel relay. The power supply module includes a working power supply, a power switch 1, and a multi-channel opto-isolation signal sampling input unit 2. The relay includes a control relay 102 and a normally closed relay 101. It also includes an operation indicator light, a fault indicator light, and an abnormal alarm light; the working power supply includes a variety of isolated and changed power supplies for powering a variety of devices.

[0040] When the power switch K is turned on, the power indicator light lights up; the microprocessor 3 (MCU) starts to work. The operation status output terminal of the microprocessor 3 is also coupled with an operation indicator light 11, and the operation indicator light 11 flashes (when there is no fault in the protected line, other indicator lights do not light up).

[0041] In this example, there is a multi-channel opto-isolation signal sampling input unit 2, which includes 6 channels in this example, respectively used to detect and collect signals of different tripping circuits. A normally closed relay 101 is set in the tripping circuit to control the on-off of the tripping circuit.

[0042] The microprocessor 3 includes a monitoring and processing unit, an action signal output terminal, a first stroboscopic pulse output terminal, a second stroboscopic pulse output terminal, and a reset unit.

[0043] As Figure 2 and Figure 3As shown, the microprocessor 3 is configured to receive the signals of the opto-isolated signal sampling input unit 2 and correspondingly feedback them to the action signal output terminal, the first strobe pulse output terminal, and the second strobe pulse output terminal. The sampling input terminal is used to receive the signals of the opto-isolated signal sampling input unit 2. The monitoring and processing unit compares the received signals with the preset values and time, and then correspondingly feedbacks them to the action signal output terminal, the first strobe pulse output terminal, and the second strobe pulse output terminal according to different signals. It can be output individually or two different output terminals can be output simultaneously. When the continuous duration of the signal input by any one of the opto-isolated signal sampling input units 2 received by the sampling input terminal is not less than the preset value, a signal is output to the action signal output terminal and the first strobe pulse output terminal. When the signal input by any one of the opto-isolated signal sampling input units 2 received by the sampling input terminal has a positive pulse width greater than 10 mS and the number of pulses is not less than 2 within the preset time, a signal is output to the second strobe pulse output terminal and the action signal output terminal.

[0044] A fault indicator light 12 is coupled to the first strobe pulse output terminal; it prompts the staff that the tripping circuit has been disconnected because there is an over-time tripping voltage in the corresponding circuit. Multiple action signal output ports are all coupled with an output signal opto-isolation unit 4. After being isolated and inverted by the output signal opto-isolation unit 4, the high-level output terminal of the output signal opto-isolation unit 4 is coupled to the drive unit 5. The action signal output terminal of the drive unit 5 is electrically connected to the coil of the normally closed relay 101. When the continuous duration of the signal input by any one of the opto-isolated signal sampling input units 2 received by the sampling input terminal is not less than the value set by the DIP switch, the corresponding action signal output port (one of OUT1 - OUT6) of the microprocessor 3 outputs a low level. This low level is output as a high level through the high-level output terminal (one of IC1 - IC6) of the output signal opto-isolation unit 4 (PS2801 - 4) and sent to the corresponding input port of the drive unit 5 (relay driver chip ULN2803). The low-level output port (one of DOUT1 - DOUT6) of the drive unit 5 (relay driver chip ULN2803) outputs a low level to drive the corresponding normally closed relay 101 (one of JK1 - JK6), and the normally closed contact of the normally closed relay 101 is opened to cut off the tripping circuit.

[0045] The action signal output terminal of the driving unit 5 is also electrically connected to the coil of the control relay 102. The action signal output terminal, the stroboscopic pulse output terminal of the control relay 102 are electrically connected to the signal transmitter. At the same time, a low level is sent from the corresponding action signal output port (OUT7) of the microprocessor 3 to the output signal opto-isolation unit 4 (PS2801-4), and is transmitted through opto-isolation to the corresponding input port of the driving unit 5 (relay driving chip ULN2803). The corresponding action signal output port (DOUT7) of the driving unit 5 (relay driving chip ULN2803) outputs a low level to pin 1 of the driving control relay 102 JK7. The coil of the relay JK7 is energized, and its external output contact operates, transmitting the stroboscopic signal to the signal transmitter. The signal transmitter sends this signal to the remote monitoring system to inform the power supply dispatcher.

[0046] The second stroboscopic pulse output terminal is coupled with a stroboscopic input terminal. The stroboscopic pulse output terminal of the driving unit 5 is connected to the abnormal warning lamp.

[0047] When the microprocessor 3 detects a signal with a positive pulse width of < preset value > 10mS and the number of pulses ≥ 2 in any one of the input signals within the set value of the DIP switch, the second stroboscopic pulse output terminal (OCUT8) outputs a stroboscopic pulse with a frequency of 1S (duty cycle 50%). This stroboscopic pulse is sent to the corresponding input port (08) of the driving unit 5 (relay driving chip (ULN2803)) after being isolated by the output signal opto-isolation unit 4 (PS2801-4). The stroboscopic pulse output terminal (DOUT8) of the driving unit 5 outputs a stroboscopic pulse with a frequency of 1S to the J8 output port. The J8 output port is actually an OC gate and can directly drive the warning indicator to flash. At the same time, the action signal output terminal (OUT7) also outputs a low level to the output signal opto-isolation unit 4, and the output signal opto-isolation unit 4 then transmits it to the driving unit 5, and the driving unit 5 controls the normally closed relay 101 and the control relay 102 to operate.

[0048] The normally closed relay 101, the warning indicator and the control relay 102 are such that the normally closed relay 101 is opened, and then the tripping circuit is disconnected, causing the control relay 102 to open. Then the signal transmitter receives the fault signal and the warning indicator flashes.

[0049] The reset module includes a reset resistor and a reset button 6. The output end of the reset button 6 is connected to the signal input end of the microprocessor 3. Once the above signals and outputs are sent out, the actions will be maintained continuously (cannot be automatically restored). To restore the above actions to the state before the actions, it is necessary to manually handle various faults on-site and then press the reset button for 2S to transfer the output end of the reset button 6 to the signal input end of the microprocessor 3. After the microprocessor 3 receives this reset signal, it will stop the output of all output ends of the module, causing the system to return to the tripping mode. If there are unhandled faults, the system will prohibit resetting.

[0050] An action indicator light is provided on each normally closed relay 101. In this way, after the corresponding normally closed relay 101 receives the signal from the action signal output end of the drive unit 5, it disconnects and the action indicator light lights up, enabling it to accurately identify which tripping circuit has a problem. However, if it is the signal output from the strobe pulse output end of the drive unit 5, multiple normally closed relays 101 will all act, multiple action indicator lights will all flash, and multiple tripping circuits will all disconnect.

[0051] SW2 is a two-bit binary DIP switch 7. Users can select the position of this DIP switch according to the application protection device, that is, the effective duration of the tripping signal set for DC switchgear protection by different manufacturers, and form a preset time value through the binary DIP switch 7. In this example, the preset values are (module preset 00 = 3S, 01 = 4S, 10 = 5S, 11 = 6S, a total of 4 groups of selections). In this example, it is 6S. That is, observe whether there is a high-level signal equal to 6S. If so, output the signal to the action signal output end and the first strobe pulse output end. Then observe whether there is a positive pulse width greater than 10mS within 6S and the number of pulses ≥ 2. If so, output the signal to the action signal output end and the second strobe pulse output end. The microprocessor 3 uses this duration to identify whether the tripping signal is abnormal and whether it is necessary to cut off the tripping and lock it. If necessary, the program can also be modified online.

[0052] Both the first strobe pulse output end and the second strobe pulse output end output strobe pulses with a frequency of 1S and a duty cycle of 50%. To achieve fast flashing to remind the inspection personnel to pay attention.

[0053] The microprocessor online programming interface 8, that is, the J2 interface, is a dedicated interface reserved by the system for online modification of the program of this module. It can be connected to a PC through a dedicated interface converter to USB to achieve online programming.

[0054] The external function expansion serial interface 9, that is, the J3 interface, is a serial data output interface reserved by the system. It can communicate with external devices to facilitate future function expansion.

[0055] In addition, the J8 socket is an OC gate output interface reserved by the system. It can directly drive an external resistive or inductive device with a current not exceeding 200 mA (a freewheeling diode needs to be externally connected for inductive loads).

[0056] The specific working process is as follows: 1. Since the module powers on, it simultaneously monitors the existence time of the voltage of 6 tripping circuits (1 of which is spare). When the voltage duration of any tripping circuit exceeds the preset value, the module will automatically cut off the corresponding tripping circuit (the action indicator light of the corresponding relay lights up), and the local warning indicator light will flash. At the same time, a "tripping circuit cut-off" signal will be sent to the signal transmitter system. This action and the three signals will remain until the "reset button" is pressed on the module for 2 seconds to restore the tripping circuit to the normal input mode. (If the circuit voltage still exists, the module will automatically repeat the above process and refuse to reset).

[0057] 2. The occurrence of the situation in "1" does not affect the module's automatic monitoring and control of other circuits, and its action and display status are the same as those in "1".

[0058] 3. When abnormal electrification such as poor contact of circuit contacts, relay contact jitter, condensation, or adhesion through excessive resistance occurs in the tripping circuit, the module uses the criterion of "continuously appearing 2 pulse signals with a width > 10 mS within 600 mS" to make the warning indicator light flash. This signal will also cut off the tripping circuit and send a signal to the signal transmitter to inform the system dispatcher of "instantaneous connection of the tripping circuit". When a primary power supply circuit short-circuits and acts, the module status is the same as that in "1". Once the module has an action, it will remain until the "reset" button is pressed on the module for 2 seconds to restore. Based on the flashing of this light and the action of the relay, determine what kind of fault has occurred, whether it is an instantaneous fault of the line that requires bilateral power supply, or whether there are faults in devices such as relays in the secondary circuit, so that the maintenance department can perform repairs as soon as possible.

[0059] The above embodiments are only used to illustrate the technical concept and features of the present invention. The purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. Monitoring and protection module for DC double-sided power supply tripping loop in urban rail transit, characterized in that It includes a power supply module and a microprocessor. The power supply module includes a working power supply, a power switch, and a multi-channel opto-isolated signal sampling input unit. The microprocessor includes a monitoring and processing unit, an action signal output terminal, a first stroboscopic pulse output terminal, a second stroboscopic pulse output terminal, and a reset unit. It also includes an output signal opto-isolation unit; The output terminals of the multi-channel opto-isolated signal sampling input units are respectively coupled to the output terminals of the trip-together circuits. Each of the trip-together circuits includes a normally-closed relay; The microprocessor is configured to receive the signals of the multi-channel opto-isolated signal sampling input units and correspondingly feedback them to the action signal output terminal, the first stroboscopic pulse output terminal, and the second stroboscopic pulse output terminal; When the monitoring and processing unit receives the signal of any opto-isolated signal sampling input unit for a continuous duration not less than a preset value, it outputs signals to the action signal output terminal and the first stroboscopic pulse output terminal. When the monitoring and processing unit receives a positive pulse with a width within the preset value and greater than 10 mS and the number of pulses is not less than 2 in the signal of any opto-isolated signal sampling input unit, it outputs signals to the second stroboscopic pulse output terminal and the action signal output terminal; The first stroboscopic pulse output terminal is coupled to a fault indicator light; The action signal output terminal is coupled to the action input terminal of the output signal opto-isolation unit. The action output terminal of the output signal opto-isolation unit is connected to a drive unit. The output terminal of the drive unit is electrically connected to the coil of the normally-closed relay. The output terminal of the drive unit is also electrically connected to the coil of a control relay. The output terminal of the control relay is connected to a signal transmitter; The second stroboscopic pulse output terminal is connected to the stroboscopic input terminal of the output signal opto-isolation unit. The stroboscopic pulse output terminal of the drive unit is connected to an abnormal alarm light; The reset unit includes a resistance reset button. The output terminal of the reset button is connected to the signal input terminal of the microprocessor.

2. The monitoring and protection module for the DC bilateral power supply inter-trip loop of urban rail transit according to claim 1, characterized in that: An action indicator light is provided on each of the normally-closed relays.

3. The monitoring and protection module for the DC bilateral power supply intertripping loop of urban rail transit according to claim 1, wherein: It also includes a binary DIP switch. The output terminal of the binary DIP switch is connected to the signal input terminal of the microprocessor and is used to form the preset value.

4. The monitoring and protection module for the DC bilateral power supply intertripping loop of urban rail transit according to claim 3, characterized in that: The operating status output terminal of the microprocessor is also coupled to an operating indicator light.

5. The monitoring and protection module for the DC bilateral power supply inter-tripping loop of urban rail transit according to claim 1, wherein: Both the first stroboscopic pulse output terminal and the second stroboscopic pulse output terminal output stroboscopic pulses with a frequency of 1S and a duty cycle of 50%.

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