Broken line detection circuit capable of switching control loop

Abstract

The utility model relates to a switching control loop disconnection detection circuit, which comprises a switching control switch, a closing loop disconnection detection optocoupler, an opening loop disconnection detection optocoupler, a third current-limiting resistor and a fifth current-limiting resistor, the other end of the switch-on loop disconnection detection optical coupler is connected to the input end of the input side of the switch-off loop disconnection detection optical coupler; the output end of the input side of the closing loop disconnection detection optocoupler is connected to the negative electrode of the power supply of the circuit breaker operating mechanism after passing through a circuit breaker closing contact and a closing coil; and the output end of the input side of the opening loop disconnection detection optocoupler is connected to the negative electrode of the power supply of the circuit breaker operating mechanism after passing through the circuit breaker opening contact and the opening coil. The on-off state of the control loop disconnection detection circuit can be adjusted according to needs through the on-off switch, on-site maintenance is facilitated, and timely detection of control loop disconnection can be realized.

Description

Technical Field

[0001] This utility model belongs to the field of switch control technology in the power distribution industry, and more specifically, relates to a disconnection detection circuit for a control loop that can be switched on or off. Background Technology

[0002] Circuit breakers are among the most critical devices in power systems. Circuit breaker failures can cause power grid accidents or escalate the scope of such accidents. The circuit breaker control circuit is a vital component for realizing the circuit breaker's functions, playing a role in control, monitoring, and protection. Related research indicates that circuit breaker control circuit failures have become a significant cause of circuit breaker malfunctions. Therefore, effective monitoring and defect alarming of the circuit breaker control circuit are crucial means to reduce circuit breaker malfunctions and prevent power outages.

[0003] Existing technologies regarding circuit breaker control circuits include:

[0004] Patent application CN202220954228.4 discloses a reversible control circuit disconnection detection circuit, including a closing circuit disconnection detection circuit and a tripping circuit disconnection detection circuit. Both the closing and tripping circuits are connected to the disconnection detection signal terminal YX_SOE. Each circuit consists of a current-limiting resistor, a filter capacitor, a reverse-biased diode, and two optocouplers for isolation. By adding this control circuit disconnection detection function, it determines whether a disconnection has occurred at the connection between primary and secondary equipment or at the closing / tripping pressure plate. Simultaneously, the disconnection detection function is introduced to detect whether a disconnection has occurred in the control circuit in real time by checking whether the master station receives the control circuit disconnection SOE. However, this patent only detects disconnections at the closing / tripping pressure plate and cannot detect disconnections in the closing / tripping coils and the connection between the closing and tripping contacts inside the circuit breaker mechanism. Furthermore, the open circuit detection circuits currently used for fault detection in circuit breaker control circuits are all in a long-term online state, which is insufficient in terms of power consumption and long-term reliability. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a disconnection detection circuit for a control loop that can be switched on or off.

[0006] The present invention adopts the following technical solution.

[0007] The first aspect of this utility model provides a disconnection detection circuit for a control circuit that can be switched on or off, including a switch on / off control switch BO1, a disconnection detection optocoupler for the closing circuit BO2, a disconnection detection optocoupler for the opening circuit BO3, a third current-limiting resistor R3, and a fifth current-limiting resistor R5; characterized in that:

[0008] One end of the activation / deactivation control switch BO1 is connected to the positive terminal of the power supply of the circuit breaker operating mechanism, and the other end is connected to the input terminal of the input side of the closing circuit disconnection detection optocoupler BO2 and the input terminal of the opening circuit disconnection detection optocoupler BO3 respectively. The activation / deactivation control signal of the control circuit disconnection detection circuit controls the activation / deactivation control switch BO1 to open and close.

[0009] The output terminal of the closing circuit disconnection detection optocoupler BO2 is connected to the negative terminal of the circuit breaker operating mechanism power supply through the circuit breaker closing contact 9 and closing coil 10 in the circuit breaker mechanism; the input terminal of the closing circuit disconnection detection optocoupler BO2 is connected to a high level through the third current limiting resistor R3, and the output terminal is grounded; the closing control circuit disconnection detection signal is led out from the input terminal of the closing circuit disconnection detection optocoupler BO2.

[0010] The output terminal of the BO3 trip circuit disconnection detection optocoupler input side is connected to the negative terminal of the circuit breaker operating mechanism power supply through the circuit breaker trip contact 11 and trip coil 12 in the circuit breaker mechanism; the input terminal of the BO3 trip circuit disconnection detection optocoupler output side is connected to a high level through the fifth current limiting resistor R5, and the output terminal is grounded. The trip control circuit disconnection detection signal is led out from the input terminal of the BO3 trip circuit disconnection detection optocoupler output side.

[0011] Preferably, the control circuit disconnection detection circuit activation / deactivation control signal is VCC high level when the control circuit disconnection detection circuit is in deactivation state, controlling the activation / deactivation control switch BO1 to open; and is 0V low level when the control circuit disconnection detection circuit is in activation state, controlling the activation / deactivation control switch BO1 to close.

[0012] Preferably, the engagement / disengagement control switch BO1 is an optocoupler, a relay, a thyristor, or a contactor.

[0013] Preferably, the activation / deactivation control switch BO1 is an optocoupler. The input terminal of the optocoupler input side of the activation / deactivation control switch BO1 is connected to the power supply VCC through the first current-limiting resistor R1, and the output terminal of the optocoupler input side of the activation / deactivation control switch BO1 is connected to the activation / deactivation control signal of the control loop disconnection detection circuit.

[0014] Preferably, the input terminal of the optocoupler output side of the switch BO1 is connected to the positive terminal of the circuit breaker operating mechanism power supply, and the output terminal is connected to the input terminal of the closing circuit disconnection detection optocoupler BO2 and the input terminal of the opening circuit disconnection detection optocoupler BO3 through the second current limiting resistor R2 and the fourth current limiting resistor R4, respectively.

[0015] Preferably, the output terminal of the optocoupler BO2 for detecting the disconnection of the closing circuit is connected to the circuit breaker closing contact 9 and the closing coil 10 in the circuit breaker mechanism through the first diode D1;

[0016] The output terminal of the optocoupler BO3, used for detecting the disconnection of the circuit breaker circuit, is connected to the circuit breaker tripping contact 11 and tripping coil 12 in the circuit breaker mechanism via the second diode D2.

[0017] Preferably, when the closing contact 9 of the circuit breaker mechanism is closed, a disconnection detection of the closing control circuit is performed; when the opening contact 11 of the circuit breaker mechanism is closed, a disconnection detection of the opening control circuit is performed.

[0018] The beneficial effect of this utility model is that, compared with the prior art,

[0019] This invention allows for adjustment of the on / off state of the control circuit disconnection detection circuit via an on / off control switch. Through the optocoupler BO2 for closing circuit disconnection detection and BO3 for opening circuit disconnection detection, this invention enables real-time detection of disconnections in the closing and opening control circuits, facilitating rapid on-site diagnosis and problem-solving, avoiding the risk of malfunctions or aborted operations due to internal logic errors in the operating mechanism, and reducing maintenance costs. The invention uses a second current-limiting resistor R2 and a fourth current-limiting resistor R4 to ensure a small current value in the detection circuit, preventing relay malfunctions. This invention has low implementation cost, is convenient and simple to implement, uses fewer components, and has certain economic advantages. Attached Figure Description

[0020] Figure 1 This is a block diagram of the disconnection detection circuit of the control loop that can be activated or deactivated according to this utility model.

[0021] The meanings of the reference numerals in the attached figures are as follows:

[0022] BO1 is the enable / disable control switch;

[0023] BO2 is an optocoupler for detecting open circuit in the closing circuit;

[0024] BO3 is an optocoupler for detecting open circuit in the tripping circuit;

[0025] 4 is the closing pressure plate, and 6 is the opening pressure plate;

[0026] 5 and 7 are the closing switch and the opening switch, respectively;

[0027] 8 represents the circuit breaker mechanism, 10 and 12 represent the closing coil and opening coil of the circuit breaker mechanism, respectively, and 9 and 11 represent the closing contact and opening contact of the circuit breaker mechanism, respectively. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. The embodiments described in this application are merely some embodiments of this utility model, and not all embodiments. Based on the spirit of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0029] like Figure 1 As shown, Embodiment 1 of this utility model provides a disconnection detection circuit for a reversible control circuit. The circuit breaker mechanism contains a closing contact and a tripping contact, which are interlocked, meaning only one contact can be closed at a time while the other is open. The reversible control circuit disconnection detection circuit includes a reversible control switch BO1, a closing circuit disconnection detection optocoupler BO2, a tripping circuit disconnection detection optocoupler BO3, a second current-limiting resistor R2, a third current-limiting resistor R3, a fourth current-limiting resistor R4, and a fifth current-limiting resistor R5. Specifically:

[0030] One end of the activation / deactivation control switch BO1 is connected to the positive terminal of the power supply of the circuit breaker operating mechanism, and the other end is connected to the input terminal of the input side of the closing circuit disconnection detection optocoupler BO2 and the input terminal of the opening circuit disconnection detection optocoupler BO3 respectively. The activation / deactivation control signal of the control circuit disconnection detection circuit controls the activation / deactivation control switch BO1 to open and close.

[0031] The output terminal of the BO2 input side of the closing circuit disconnection detection optocoupler is connected to the negative terminal of the circuit breaker operating mechanism power supply through the circuit breaker closing contact and closing coil in the circuit breaker mechanism; the input terminal of the BO2 output side of the closing circuit disconnection detection optocoupler is connected to a high level through the third current limiting resistor R3, and the output terminal is grounded. The closing control circuit disconnection detection signal is led out from the input terminal of the BO2 output side of the closing circuit disconnection detection optocoupler.

[0032] The output terminal of the BO3 trip circuit disconnection detection optocoupler input side is connected to the negative terminal of the circuit breaker operating mechanism power supply through the circuit breaker trip contact and trip coil in the circuit breaker mechanism; the input terminal of the BO3 trip circuit disconnection detection optocoupler output side is connected to a high level through the fifth current limiting resistor R5, and the output terminal is grounded. The trip control circuit disconnection detection signal is led out from the input terminal of the BO3 trip circuit disconnection detection optocoupler output side.

[0033] Preferably, the control circuit disconnection detection circuit activation / deactivation control signal is VCC high level when the control circuit disconnection detection circuit is in deactivation state, controlling the activation / deactivation control switch BO1 to open; and is 0V low level when the control circuit disconnection detection circuit is in activation state, controlling the activation / deactivation control switch BO1 to close.

[0034] Preferably, the engagement / disengagement control switch BO1 is an optocoupler, a relay, a thyristor, or a contactor.

[0035] Preferably, the activation / deactivation control switch BO1 is an optocoupler. The input terminal of the optocoupler input side of the activation / deactivation control switch BO1 is connected to the power supply VCC through the first current-limiting resistor R1, and the output terminal of the optocoupler input side of the activation / deactivation control switch BO1 is connected to the activation / deactivation control signal of the control loop disconnection detection circuit.

[0036] Preferably, the input terminal of the optocoupler output side of the switch BO1 is connected to the positive terminal of the circuit breaker operating mechanism power supply, and the output terminal is connected to the input terminal of the closing circuit disconnection detection optocoupler BO2 and the input terminal of the opening circuit disconnection detection optocoupler BO3 through the second current limiting resistor R2 and the fourth current limiting resistor R4, respectively.

[0037] The second current-limiting resistor R2 and the fourth current-limiting resistor R4 are used to ensure that the detection circuit has a small current value, which will not cause the relay to malfunction.

[0038] Preferably, the output terminal of the optocoupler BO2, which is used for detecting the disconnection of the closing circuit, is connected to the closing contact and closing coil of the circuit breaker mechanism through the first diode D1.

[0039] The output terminal of the optocoupler BO3, used for the open circuit detection, is connected to the circuit breaker tripping contact and tripping coil in the circuit breaker mechanism via a second diode D2. Preferably, the control circuit open circuit detection circuit further includes a first diode D1 and a second diode D2.

[0040] The positive terminal of the first diode D1 is connected to the negative terminal of the second optocoupler diode BO2, and the negative terminal of the first diode D1 is connected to the connection point between the second switch K6 and the closing switch of the circuit breaker mechanism.

[0041] The positive terminal of the second diode D2 is connected to the negative terminal of the third optocoupler diode BO3, and the negative terminal of the second diode D2 is connected to the connection point between the first switch K5 and the trip switch of the circuit breaker mechanism.

[0042] The first diode D1 and the second diode D2 are used to prevent reverse current from flowing through the coil.

[0043] Preferably, when the closing contact 9 of the circuit breaker mechanism is closed, a disconnection detection of the closing control circuit is performed; when the opening contact 11 of the circuit breaker mechanism is closed, a disconnection detection of the opening control circuit is performed.

[0044] It should be noted that the process of detecting broken wires in this embodiment is as follows:

[0045] When the control circuit disconnection detection circuit is in the off-run state, the activation / deactivation control signal input VCC is at a high level. At this time, the activation / deactivation control switch BO1 is not conducting, the second optocoupler diode BO2 and the third optocoupler diode BO3 have no current, and the disconnection detection signal of the closing control circuit and the disconnection detection signal of the opening control circuit are at a high level VCC.

[0046] When the control circuit disconnection detection circuit is in operation, the activation / deactivation control signal input is 0V low level, and the activation / deactivation control switch BO1 is turned on. If there are no abnormalities in the circuit breaker tripping control circuit and closing control circuit, the positive terminal HV+ of the operating mechanism power supply is connected to the negative terminal HV- of the operating mechanism power supply through the second current-limiting resistor R2, the second optocoupler diode BO2, and the closing coil of the circuit breaker mechanism. At the same time, the positive terminal HV+ of the operating mechanism power supply is also connected to the negative terminal HV- of the operating mechanism power supply through the fourth current-limiting resistor R4, the third optocoupler diode BO3, and the tripping coil of the circuit breaker mechanism. At this time, the third optocoupler BO3 and the second BO2 are turned on, and the disconnection detection signal of the tripping control circuit and the disconnection detection signal of the closing control circuit are both 0V low level. The 0V low level signal can be sent to the device CPU for logical judgment. If there is an abnormality such as an open circuit in the circuit breaker tripping control circuit or the closing control circuit, the third optocoupler BO3 or the second optocoupler BO2 is not turned on, and the disconnection detection signal of the tripping control circuit or the disconnection detection signal of the closing control circuit is still VCC high level. The third current-limiting resistors R3 and R5 are the pull-up resistors for the collectors of the second optocoupler BO2 and the third optocoupler BO3 transistors, respectively, to the VCC voltage.

[0047] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0048] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0049] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0050] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A disconnection detection circuit for a control loop that can be switched on or off, comprising a switch-on / off control switch (BO1), a disconnection detection optocoupler for the closing loop (BO2), a disconnection detection optocoupler for the opening loop (BO3), a third current-limiting resistor (R3), and a fifth current-limiting resistor (R5); characterized in that: One end of the activation / deactivation control switch (BO1) is connected to the positive terminal of the power supply of the circuit breaker operating mechanism, and the other end is connected to the input terminal of the closing circuit disconnection detection optocoupler (BO2) and the input terminal of the opening circuit disconnection detection optocoupler (BO3). The activation / deactivation control signal of the control circuit disconnection detection circuit controls the activation / deactivation control switch (BO1) to open and close. The output terminal of the closing circuit disconnection detection optocoupler (BO2) is connected to the negative terminal of the circuit breaker operating mechanism power supply after passing through the circuit breaker closing contact (9) and closing coil (10) in the circuit breaker mechanism; the input terminal of the closing circuit disconnection detection optocoupler (BO2) is connected to a high level through the third current limiting resistor (R3), and the output terminal is grounded. The closing control circuit disconnection detection signal is led out from the input terminal of the closing circuit disconnection detection optocoupler (BO2); The output terminal of the trip circuit disconnection detection optocoupler (BO3) is connected to the negative terminal of the circuit breaker operating mechanism power supply after passing through the circuit breaker trip contact (11) and trip coil (12) in the circuit breaker mechanism; the input terminal of the trip circuit disconnection detection optocoupler (BO3) is connected to a high level through the fifth current limiting resistor (R5), and the output terminal is grounded. The trip control circuit disconnection detection signal is led out from the input terminal of the trip circuit disconnection detection optocoupler (BO3).

2. The disconnection detection circuit of the reversible control loop according to claim 1, characterized in that: The control circuit disconnection detection circuit is in the off-run state when the control circuit disconnection detection circuit is at a high level of VCC, which controls the disconnection control switch (BO1) to open. When the control circuit disconnection detection circuit is in the running state, the control circuit disconnection detection circuit is at a low level of 0V, which controls the disconnection control switch (BO1) to close.

3. The disconnection detection circuit of the reversible control loop according to claim 1 or 2, characterized in that: The on / off control switch (BO1) is an optocoupler, relay, thyristor, or contactor.

4. The disconnection detection circuit of the reversible control loop according to claim 3, characterized in that: The activation / deactivation control switch (BO1) is an optocoupler. The input terminal of the optocoupler input side of the activation / deactivation control switch (BO1) is connected to the power supply VCC through the first current-limiting resistor (R1), and the output terminal of the optocoupler input side of the activation / deactivation control switch (BO1) is connected to the activation / deactivation control signal of the control loop disconnection detection circuit.

5. The disconnection detection circuit of the reversible control loop according to claim 4, characterized in that: The input terminal of the optocoupler output side of the switch (BO1) is connected to the positive terminal of the circuit breaker operating mechanism power supply. The output terminal is connected to the input terminal of the closing circuit disconnection detection optocoupler (BO2) and the input terminal of the opening circuit disconnection detection optocoupler (BO3) through the second current limiting resistor (R2) and the fourth current limiting resistor (R4), respectively.

6. The disconnection detection circuit of the reversible control loop according to claim 1, characterized in that: The output terminal of the optical coupler (BO2) for detecting the disconnection of the closing circuit is connected to the circuit breaker closing contact (9) and closing coil (10) in the circuit breaker mechanism through the first diode (D1); The output terminal of the optocoupler (BO3) for detecting the disconnection of the tripping circuit is connected to the tripping contact (11) and tripping coil (12) in the circuit breaker mechanism via the second diode (D2).

7. The disconnection detection circuit of the reversible control loop according to claim 1, characterized in that: When the closing contact (9) of the circuit breaker mechanism is closed, the closing control circuit is checked for disconnection; when the opening contact (11) of the circuit breaker mechanism is closed, the opening control circuit is checked for disconnection.

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