Subway station control box equipment protection circuit

Abstract

The utility model discloses an equipment protection circuit for a subway station control box. The equipment protection circuit comprises a UPS (Uninterrupted Power Supply) and a change-over switch S, the UPS is connected to a main loop of the load power supply circuit. The two ends of the change-over switch S are connected to the two sides of the UPS respectively. The system further comprises a first control branch and a second control branch. The first control branch comprises a normally open contact of an intermediate relay KN and a button SB2, and the normally open contact of the intermediate relay KN and the button SB2 are connected in parallel; one end of the first control branch is connected with the L3 line, and the other end is connected with the L2 line; the second control branch comprises an intermediate relay KN coil, a current transformer TA and a rectifier bridge. According to the utility model, through the connection of the UPS, the load power supply circuit can obtain uninterrupted power support when the main power supply fails, so that the normal operation of key equipment of the subway station is ensured. The change-over switch S can quickly switch between the main power supply and the UPS, and can ensure that a control loop can still be connected to the main power supply for operation when the UPS is overhauled.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of equipment protection circuit, in particular to a kind of subway station control box equipment protection circuit. BACKGROUND

[0002] In modern urban transportation system, as efficient, convenient public transport, its safe and stable operation is crucial for urban traffic. Subway station control box equipment is an important part of the subway operation control system, which is responsible for receiving and executing control commands to ensure the normal operation of subway vehicles. However, subway station control box equipment may encounter various abnormal conditions during operation, such as overvoltage, overcurrent, short circuit, etc. These conditions may cause damage to the equipment, and even affect the safety of the entire subway system.

[0003] Traditional subway station control box equipment protection circuit mainly relies on passive protection elements such as fuses and circuit breakers. These elements can cut off the power supply when a fault occurs to prevent equipment damage. However, this protection method has certain limitations, such as long response time, inability to implement early warning and diagnosis of faults, etc. With the development of electronic technology, protection circuit has gradually become a research hotspot, which can monitor the running state of equipment in real time, quickly and accurately identify faults, and take appropriate protection measures to improve the reliability and safety of subway station control box equipment. SUMMARY

[0004] The utility model aims at overcoming the deficiency of prior art, provide a kind of subway station control box equipment protection circuit, adopt the form of UPS cooperation control circuit, protect subway station control box equipment, ensure the safe operation of subway system.

[0005] The utility model aims at overcoming the deficiency of prior art, provide a kind of subway station control box equipment protection circuit, adopt the form of UPS cooperation control circuit, protect subway station control box equipment, ensure the safe operation of subway system.

[0006] A kind of subway station control box equipment protection circuit, including UPS and switch S;UPS is connected on the main circuit of load power supply circuit, and the two ends of switch S are connected on the two sides of UPS;

[0007] It further includes first control branch and second control branch;First control branch includes normally open contact of intermediate relay KN, button SB2, and normally open contact of intermediate relay KN and button SB2 are connected in parallel;One end of first control branch is connected with L3 line, and the other end is connected with L2 line;

[0008] Second control branch includes intermediate relay KN coil, current transformer TA, rectifier bridge, current transformer TA is arranged at L3 line, current transformer TA is connected with rectifier bridge, and rectifier bridge is connected with intermediate relay KN coil.

[0009] As a preferred mode, a fuse is arranged on the main circuit of the load power supply circuit.

[0010] As a preferred mode, a fuse is arranged on the first control branch.

[0011] As a preferred mode, a contactor KM is arranged on the first control branch, the coil of the contactor KM is connected in series with the button SB2, and the normally open contact of the contactor KM is connected in series with the normally open contact of the intermediate relay KN.

[0012] As a preferred mode, a button switch SB1 is arranged on the first control branch, the button switch SB1 is connected in series with the button SB2, and the normally open contact of the contactor KM is connected in series with the normally open contact of the intermediate relay KN to form a bypass, the bypass is connected in parallel with the button SB2.

[0013] As a preferred mode, the second control branch further comprises a triode VT1 and a triode VT2, the collector of the triode VT1 is connected with a resistor R7 and a resistor R8, the emitter of the triode VT1 is connected with the emitter of the triode VT2 and a resistor R9, the base of the triode VT2 is connected with the resistor R8, the resistor R7 is further connected with the resistor R2, and the resistor R2 is arranged on a voltage division branch, the voltage division branch is connected with the resistor R9 or the rectifier bridge; there is a connection point on the voltage division branch, the connection point is connected to the base of the triode VT1, and the resistor R2 is arranged between the connection point and the resistor R7.

[0014] As a preferred mode, the voltage division branch is connected in parallel with a resistor R1.

[0015] As a preferred mode, the voltage division branch is connected in parallel with a capacitor C1.

[0016] As a preferred mode, one end of the coil of the intermediate relay KN is connected with the collector of the triode VT2, and the other end of the coil of the intermediate relay KN is connected with the resistor R7.

[0017] As a preferred mode, a resistor R3 and a potentiometer RM are arranged on the voltage division branch, the first static contact of the potentiometer is connected with the resistor R2, and the second static contact of the potentiometer is connected with the resistor R3; the moving contact of the potentiometer is connected with a voltage stabilizing tube VS1, and the voltage stabilizing tube VS1 is connected to the base of the triode VT1.

[0018] As a preferred mode, an inductor L is connected in parallel with the coil of the intermediate relay KN, and a reed switch J is arranged correspondingly beside the inductor L, the reed switch J is connected to an alarm circuit, the alarm circuit comprises a bidirectional thyristor BCR, a light emitting diode D, a buzzer A, a resistor R10 and a power supply BAT, the bidirectional thyristor BCR, the light emitting diode D, the buzzer A, the resistor R10 and the power supply BAT are connected in sequence, the control end of the bidirectional thyristor BCR is connected to the reed switch, and the reed switch is further connected to the negative electrode of the power supply BAT.

[0019] The utility model has at least the following beneficial effects: the utility model through the connection of UPS, has guaranteed that the load power supply circuit can get uninterrupted power support when the main power supply fails, thereby guaranteeing the normal operation of the key equipment of subway station. The switching switch S can switch between the main power supply and the UPS quickly, and the control loop can still be connected to the main power supply for operation when the UPS is overhauled. The parallel design of the normally open contact of the intermediate relay KN in the first control branch and the button SB2 provides two control modes of manual and automatic, which is convenient for operators to select the control mode according to the actual situation. The use of the rectifier bridge ensures the stable output of the current, and the connection with the intermediate relay KN coil provides the necessary control function, enhancing the stability and safety of the circuit. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be briefly introduced the drawings needed to be used in the embodiments, it should be understood, the following drawings only show the embodiment of the utility model, therefore should not be considered as the limitation to the scope, for the ordinary skilled person in the art, under the premise of not paying the creative labor, still can obtain other related drawings according to these drawings.

[0021] Figure 1 It is a structural schematic diagram of the embodiment of the utility model. DETAILED DESCRIPTION

[0022] The technical scheme of the utility model will be described in detail below in combination with the drawings, but the protection scope of the utility model is not limited to the following.

[0023] In the following, different embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that the present disclosure is not limited to the specific forms disclosed herein, but should be interpreted to cover different changes, equivalents and / or replacements of the embodiments of the present disclosure. In describing the drawings, similar reference numerals can be used to indicate similar constituent elements.

[0024] The expressions used in different embodiments of the present disclosure, if there is "first", "second", "the first" or "the second", can modify different elements, regardless of order and / or importance, without limiting the corresponding elements. For example, the first user device and the second user device refer to different user devices, although both of them are user devices. For example, the first element can be referred to as the second element, and similarly, the second element can be referred to as the first element, without departing from the scope of the present disclosure.

[0025] It should be appreciated that specific details are given in the following description to provide a thorough understanding of the example embodiments. However, well-known processes, structures and techniques have been omitted so as to avoid obscuring the examples. In other instances, well-known processes, structures and techniques have been actually described in detail to provide a thorough understanding of the examples.

[0026] As shown in Figure 1 The utility model discloses a kind of equipment (load) protection circuit, including UPS and switch S;UPS is connected on the main circuit of load power supply circuit, and the two ends of switch S are connected on the two sides of UPS respectively;

[0027] It further includes first control branch and second control branch;First control branch includes normally open contact of intermediate relay KN, button SB2, and normally open contact of intermediate relay KN and button SB2 are connected in parallel;One end of first control branch is connected with L3 line, and the other end is connected with L2 line;

[0028] Second control branch includes intermediate relay KN coil, current transformer TA, rectifier bridge, current transformer TA is arranged at L3 line, current transformer TA is connected with rectifier bridge, and rectifier bridge is connected with intermediate relay KN coil. Figure 1 L1, L2, L3 in the three-phase power supply, the primary coil of current transformer TA is connected in series with L3 line of main circuit, and the secondary coil of current transformer TA is connected with rectifier bridge.

[0029] The embodiment is connected with uninterrupted power supply (UPS), ensures that load power supply circuit can obtain continuous power support when main power supply fails, thereby guaranteeing the stable operation of key equipment of subway station. Switch S can realize rapid switching between main power supply and UPS, ensure that control circuit can still be connected to main power supply operation when UPS is maintained. In first control branch, the parallel configuration of normally open contact of intermediate relay KN and button SB2 provides two modes of manual and automatic control, which is convenient for operating personnel to select appropriate control mode according to actual conditions. Current transformer TA in second control branch can monitor the current passing through L3 line, and when the current exceeds the set value, TA will trigger rectifier bridge and intermediate relay KN coil, thereby cutting off the power supply to prevent overload from causing damage to equipment (such as motor). The application of rectifier bridge ensures the stability of current output, and the connection with intermediate relay KN coil provides the necessary control function, improves the stability and safety of the circuit.

[0030] In a preferred embodiment, a fuse FU1 is provided on the main circuit of the load power supply circuit.

[0031] In a preferred embodiment, a fuse FU2 is provided in the first control branch.

[0032] The fuse can provide overload protection, when the current in the circuit exceeds a predetermined value, the fuse will automatically disconnect, thereby preventing damage to the device or fire risk caused by overload. The fuse can also provide short-circuit protection, once a short circuit occurs in the circuit, the fuse will quickly cut off the current, protecting other components in the circuit from damage. In addition, the replacement cost of the fuse is relatively low, easy to maintain and replace. The fuse helps to improve the reliability of the circuit, because the fuse can quickly respond to abnormal conditions, reducing downtime.

[0033] In a preferred embodiment, the first control branch is provided with a contactor KM, the coil of the contactor KM is connected in series with the button SB2 (or push button switch or self-resetting switch), and the normally open contact of the contactor KM is connected in series with the normally open contact of the intermediate relay KN.

[0034] In a preferred embodiment, a push button switch SB1 is provided in the first control branch, the push button switch SB1 is connected in series with the push button SB2; the normally open contact of the contactor KM is connected in series with the normally open contact of the intermediate relay KN to form a bypass, and the bypass is connected in parallel with the push button SB2.

[0035] In a preferred embodiment, the second control branch further includes a triode VT1 and a triode VT2, the collector of the triode VT1 is connected with a resistor R7 and a resistor R8, the emitter of the triode VT1 is connected with the emitter of the triode VT2 and a resistor R9, the base of the triode VT2 is connected with the resistor R8, the resistor R7 and the resistor R9 are connected to a rectifier bridge, the resistor R7 is further connected with a resistor R2, the resistor R2 is provided in a voltage dividing branch, the voltage dividing branch is connected with the resistor R9 or the rectifier bridge; there is a connection point in the voltage dividing branch, the connection point is connected to the base of the triode VT1, and a resistor R2 is provided between the connection point and the resistor R7. By controlling the on-off of the triode VT1 and the triode VT2, the on-off of the intermediate relay KN can be controlled, and the control of the first control branch can be realized.

[0036] In a preferred embodiment, the voltage dividing branch is connected in parallel with a resistor R1, which plays a role of shunt and impedance increase. The voltage dividing branch is connected in parallel with a capacitor C1, the capacitor C1 and the resistor R1 can form an RC parallel circuit, the main function of which is filtering, i.e. reducing the impedance to high-frequency signals, so that high-frequency signals can pass through more easily, while having a larger impedance to direct current signals or low-frequency signals, making them less likely to pass through.

[0037] In a preferred embodiment, one end of the coil of the intermediate relay KN is connected to the collector of the triode VT2, and the other end of the coil of the intermediate relay KN is connected to the resistor R7.

[0038] In a preferred embodiment, a resistor R3 and a (adjustable) potentiometer RM are provided on the voltage dividing branch, the first static contact of the potentiometer is connected to the resistor R2, the second static contact of the potentiometer is connected to the resistor R3; the moving contact of the potentiometer is connected to the stabilizing tube VS1, and the stabilizing tube VS1 is connected to the base of the triode VT1. By adjusting the potentiometer RM, the voltage applied to the stabilizing tube VS1 can be made lower than its breakdown voltage when the device or load is normally operating, the triode VT1 is cut off, the triode VT2 is turned on, and the intermediate relay KN is attracted, its normally open contact is closed, and the contactor KM is self-locked. In addition, when the L3 line is powered off, the secondary side of the current transformer TA has no induced voltage, and the relay KN is de-energized and released, its normally open contact is opened, and the KM is de-energized and released, and the device stops. When the L1 or L2 line is powered off, the current of the L3 line increases, the output voltage of the rectifier bridge rises, the stabilizing tube VS1 is broken down, and then the triode VT1 is turned on, the triode VT2 is cut off, and the intermediate relay KN and the contactor KM are sequentially de-energized and released, and the device stops. Therefore, the circuit can effectively protect the device.

[0039] In a preferred embodiment, the back end of the stabilizing tube VS1 is connected to a resistor R4, the resistor R4 is connected in parallel with a stabilizing tube VS2, and the parallel circuit composed of the resistor R4 and the stabilizing tube VS2 is respectively connected to a resistor R5, a normally closed contact of the intermediate relay KN, and a capacitor C2. The resistor R5 is connected to the base of the triode VT1, the base of the triode VT1 is also connected to a resistor R6, and the normally closed contact of the intermediate relay KN, the resistor R6, and the capacitor C2 are connected together and then connected to the resistor R9 or the rectifier bridge.

[0040] In a preferred embodiment, the parameters of the elements are provided. The capacitor C1 is 50uF-100uF, the capacitor C2 is 50uF-100uF. The resistor R1 is 10KΩ-20KΩ, the resistor R2 is 10KΩ-20KΩ, the resistor R3 is 1KΩ-5KΩ, the resistor R4 is 22KΩ-50KΩ, the resistor R5 is 1KΩ-5KΩ, the resistor R6 is 10KΩ-20KΩ, the resistor R7 is 5KΩ-10KΩ, the resistor R8 is 10KΩ-20KΩ, the resistor R9 is 50KΩ-100KΩ, and the resistor R10 is 10Ω-100Ω. Preferably, the capacitor C1 is 100uF, the capacitor C2 is 100uF. The resistor R1 is 20KΩ, the resistor R2 is 15KΩ, the resistor R3 is 1.8KΩ, the resistor R4 is 47KΩ, the resistor R5 is 3KΩ, the resistor R6 is 10KΩ, the resistor R7 is 5.1KΩ, the resistor R8 is 10KΩ, the resistor R9 is 51KΩ, the resistor R10 is 100Ω, the power supply BAT is 6V, a plug-in power supply can be used, the stabilizing tubes VS1 and VS2 are model 2CW56, the intermediate relay can be a jzx-10m electromagnetic relay, and the triodes VT1 and VT2 are model 3DG6.

[0041] In a preferred embodiment, an inductor L is connected in parallel to the coil of the intermediate relay KN, and a reed switch J is provided in correspondence with the inductor L, the reed switch J being connected to an alarm circuit, the alarm circuit comprising a bidirectional thyristor BCR, a light emitting diode D, a buzzer A, a resistor R10 and a power supply BAT, the bidirectional thyristor BCR, the light emitting diode D, the buzzer A, the resistor R10 and the power supply BAT being connected in sequence, the control end (pin G) of the bidirectional thyristor BCR being connected to the reed switch, and the reed switch being further connected to the negative pole of the power supply BAT. During operation of the device, the magnetic spring switch of the reed switch J is attracted, the bidirectional thyristor BCR is turned on, the light emitting diode D emits light, and the buzzer also produces sound, thereby reminding personnel to avoid intrusion. Moreover, once the sound and light disappear, it can be determined that the subway station control box device or circuit is malfunctioning, and repair work can be immediately carried out. The sound and light can be determined according to the situation, and in an embodiment, only the light emitting diode D or the buzzer A (not shown in the figure) can be connected to the circuit to play a reminding role.

[0042] Although the preferred embodiments of the present application have been described, those skilled in the art who are familiar with the basic inventive concept can make further changes and modifications to the embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application. The above description is only the preferred embodiments of the present application and is not intended to limit the present application. It should be noted that any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A subway station control box equipment protection circuit, characterized by: The UPS and a switch S are included; the UPS is connected to the main circuit of the load power supply circuit, and the switch S is connected to the two sides of the UPS respectively; The first control branch and the second control branch are further included; the first control branch includes the normally open contact of the intermediate relay KN and the button SB2, and the normally open contact of the intermediate relay KN and the button SB2 are connected in parallel; one end of the first control branch is connected to the L3 line, and the other end is connected to the L2 line; The second control branch includes the coil of the intermediate relay KN, the current transformer TA and the rectifier bridge; the current transformer TA is arranged at the L3 line, the current transformer TA is connected to the rectifier bridge, and the rectifier bridge is connected to the coil of the intermediate relay KN.

2. The protection circuit for a subway station control cabinet equipment according to claim 1, characterized in that: The main circuit of the load power supply circuit is provided with a fuse.

3. The protection circuit of a subway station control box equipment according to claim 1 or 2, characterized in that: The first control branch is provided with a fuse.

4. The protection circuit for a subway station control cabinet equipment according to claim 3, characterized in that: The first control branch is provided with the contactor KM, the coil of the contactor KM is connected in series with the button SB2, and the normally open contact of the contactor KM is connected in series with the normally open contact of the intermediate relay KN.

5. A protection circuit for a subway station control cabinet equipment according to claim 4, characterized in that: The first control branch is provided with the button switch SB1, the button switch SB1 is connected in series with the button SB2; the normally open contact of the contactor KM and the normally open contact of the intermediate relay KN form a bypass after being connected in series, and the bypass is connected in parallel with the button SB2.

6. The subway station control box equipment protection circuit according to claim 1, characterized in that: The second control branch further includes the triode VT1 and the triode VT2; the collector of the triode VT1 is connected to the resistor R7 and the resistor R8, the emitter of the triode VT1 is connected to the emitter of the triode VT2 and the resistor R9, the base of the triode VT2 is connected to the resistor R8, the resistor R7 and the resistor R9 are connected to the rectifier bridge, the resistor R7 is further connected to the resistor R2, the resistor R2 is arranged on a voltage division branch, the voltage division branch is connected to the resistor R9 or the rectifier bridge; there is a connection point on the voltage division branch, the connection point is connected to the base of the triode VT1, and the resistor R2 is arranged between the connection point and the resistor R7.

7. A protection circuit for a subway station control cabinet equipment according to claim 6, characterized in that: The voltage division branch is connected in parallel with the capacitor C1.

8. The subway station control box equipment protection circuit according to claim 6, characterized in that: One end of the coil of the intermediate relay KN is connected to the collector of the triode VT2, and the other end of the coil of the intermediate relay KN is connected to the resistor R7.

9. The subway station control box equipment protection circuit according to claim 6, characterized in that: The voltage division branch is provided with the resistor R3 and the potentiometer RM; the first static contact of the potentiometer is connected to the resistor R2, and the second static contact of the potentiometer is connected to the resistor R3; the moving contact of the potentiometer is connected to the stabilizing tube VS1, and the stabilizing tube VS1 is connected to the base of the triode VT1.

10. A protection circuit for a control cabinet of a subway station according to any one of claims 6 to 9, characterized in that: The inductor L is connected in parallel beside the coil of the intermediate relay KN, and the reed switch J is correspondingly arranged beside the inductor L; the reed switch J is connected to an alarm circuit, and the alarm circuit includes the bidirectional thyristor BCR, the light emitting diode D, the buzzer A, the resistor R10 and the power supply BAT; the bidirectional thyristor BCR, the light emitting diode D, the buzzer A, the resistor R10 and the power supply BAT are connected in sequence, the control end of the bidirectional thyristor BCR is connected to the reed switch, and the reed switch is further connected to the negative electrode of the power supply BAT.

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