An electrical fault lockout circuit based on a dual position relay

Abstract

This utility model discloses an electrical fault interlocking circuit based on a dual-position relay, belonging to the technical field of electrical fault interlocking circuits. It includes a positive power supply +KM and a negative power supply -KM for the control circuit, and a circuit breaker Q0 connected between the positive power supply +KM and the negative power supply -KM. It also includes an indicator light HL3 and a dual-position relay K1; the indicator light HL3 and the dual-position relay K1 are respectively connected between the positive power supply +KM and the negative power supply -KM of the control circuit. By utilizing the memory function of the dual-position relay K1, a function similar to an interlocking relay is achieved. When an external fault is not cleared, closing operation is prohibited. Only after the fault is cleared can the dual-position relay K1 be reset by pressing the reset button FA, thereby releasing the interlock and allowing closing operation to prevent the fault from spreading.

Description

Technical Field

[0001] This utility model relates to an electrical fault interlocking circuit based on a dual-position relay, belonging to the technical field of electrical fault interlocking circuits. Background Technology

[0002] In 10kV power distribution systems, circuit breakers are core components of control and protection circuits, and the safety of their closing interlocking circuits is crucial. Currently, the conventional wiring method for 10kV circuit breaker closing interlocking circuits mainly uses interlocking relays to achieve interlocking for electrical faults. This conventional solution, through the switching action of the relay, disconnects the closing circuit when a line fault or equipment abnormality is detected, preventing the circuit breaker from blindly closing, thereby achieving the purpose of protecting the power distribution system.

[0003] Existing interlocking relays are typically independent electromagnetic components, which not only have high procurement costs but also require additional independent power supply modules, complex contact systems, and secondary circuits. This increases not only the initial procurement cost of the equipment but also the subsequent investment of manpower and resources during installation and commissioning.

[0004] Therefore, it is necessary to build a simpler, lower-cost, safer and more reliable "electrical interlocking" system. Through multiple logic judgments and controls, the closing conditions of the circuit breaker can be monitored and verified in a comprehensive and multi-level manner to prevent misoperation or abnormal conditions in the circuit, reduce the incidence of electrical accidents, and ensure the safety and reliability of the circuit. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide an electrical fault interlocking circuit based on a dual-position relay, which further improves the safety and reliability of the electrical fault interlocking circuit and facilitates debugging and maintenance.

[0006] The technical problem to be solved by this utility model is achieved by the following technical solution:

[0007] An electrical fault interlocking circuit based on a dual-position relay includes a positive power supply +KM and a negative power supply -KM of the control circuit, and a circuit breaker Q0 connected between the positive power supply +KM and the negative power supply -KM of the control circuit. The test position switch S8, the working position switch S9, and the positive terminal of the trip coil TC1 of the circuit breaker Q0 are all connected to the positive power supply +KM. The negative terminals of the anti-pumping relay K0, the closing coil CC, and the trip coil TC1 of the circuit breaker Q0 are all connected to the negative power supply -KM. The circuit breaker is characterized by further including an indicator light HL3 and a dual-position relay K1.

[0008] The signal light HL3 and the dual-position relay K1 are respectively connected between the positive power supply +KM and the negative power supply -KM of the control circuit;

[0009] The dual-position relay K1 includes:

[0010] The first normally open contact is connected between the positive power supply +KM and the trip coil TC1 of circuit breaker Q0;

[0011] The first normally closed contact is connected at one end to the positive terminal of the test position switch S8 and working position switch S9 of the circuit breaker Q0 after being connected in parallel, and at the other end to the positive power supply +KM.

[0012] After the second normally open contact is connected in series with the signal light HL3, the second normally open contact and the signal light HL3 are connected together between the positive power supply +KM and the negative power supply -KM.

[0013] Preferably, the dual-position relay K1 includes an external operating contact P14 that controls the operation of the internal coil of the dual-position relay K1.

[0014] Preferably, the dual-position relay K1 includes a reset button FA for locking and resetting the dual-position relay K1.

[0015] The beneficial effects of this utility model are:

[0016] (1) By receiving one or more input signals, the state switching of the dual-position relay K1 is controlled. Through multiple logic judgments and controls, as well as the position holding function of the dual-position relay K1, the first normally open contact of the dual-position relay K1 closes to trip the circuit breaker, the first normally closed contact opens to disconnect the closing circuit, so that the closing coil cannot be energized in time, thus playing the closing lockout function. The second normally open contact closes to make the indicator light light up, indicating the fault action, that is, the dual-position relay K1 is activated.

[0017] (2) By utilizing the memory function of the dual-position relay K1, it can maintain its state, thereby achieving a function similar to a lockout relay. When the external fault is not eliminated, the closing operation is prohibited. Only after the fault is eliminated can the dual-position relay K1 be reset by the reset button FA, thereby achieving the purpose of unlocking. At this time, the closing operation is allowed, preventing the fault from spreading, protecting the safe operation of the equipment, avoiding property loss, and realizing a safer and more reliable electrical fault lockout circuit function. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the wiring and operation steps of an electrical fault interlocking circuit modified using a dual-position relay K1.

[0019] Figure 2 This is the internal circuit diagram of the dual-position relay K1.

[0020] In the diagram: Positive power supply +KM; Negative power supply -KM; Circuit breaker Q0; Test position switch S8; Working position switch S9; Opening coil TC1; Anti-pumping relay K0; Closing coil CC; Opening coil TC1; Circuit breaker auxiliary contact S5; Energy storage position switch S2; Indicator light HL3; Dual-position relay K1; First normally open contacts 7, 14; First normally closed contacts 3, 18; Second normally open contacts 8, 13; External operating contact P14; Reset button FA. Detailed Implementation

[0021] To facilitate a clear understanding of the technical means, creative features, objectives, and effects of this utility model, the following description, in conjunction with specific illustrations, further elaborates on this utility model.

[0022] like Figure 1 As shown, this electrical fault interlocking circuit based on a dual-position relay includes a positive power supply +KM and a negative power supply -KM in the control circuit, and a circuit breaker Q0 connected between the positive power supply +KM and the negative power supply -KM in the control circuit. The test position switch S8, the working position switch S9, and the positive terminal of the trip coil TC1 of the circuit breaker Q0 are all connected to the positive power supply +KM. The negative terminal of the anti-pumping relay K0, the closing coil CC, and the trip coil TC1 of the circuit breaker Q0 are all connected to the negative power supply -KM.

[0023] Circuit breaker Q0 is a commercially available and mature product. Circuit breaker Q0 also includes the following internal structure:

[0024] Test position switch S8: When the circuit breaker trolley is in the test position, the contact of test position switch S8 is closed; when it leaves the test position, the contact of test position switch S8 is open.

[0025] The working position switch S9 is closed when the circuit breaker trolley is in the working position and open when it leaves the working position.

[0026] The circuit breaker auxiliary contact S5 is normally open, representing the closed state, and normally closed, representing the open state.

[0027] If the anti-pumping relay K0 causes a fault-related closing command to persist, the circuit breaker Q0 will continuously and repeatedly open and close. The anti-pumping relay K0 ensures that if a closing operation is immediately followed by a opening operation, the preceding closing command will not trigger a second closing operation, thus preventing adverse situations. If a second closing operation is required, the previous closing command must disappear before it is reissued.

[0028] The energy storage position switch S2 is closed when the circuit breaker Q0 has completed energy storage, and open when energy storage has not been completed.

[0029] When the closing coil CC is energized, the circuit breaker Q0 closes, and the corresponding auxiliary contact S5 of the circuit breaker changes from normally open to normally closed, and from normally closed to normally open.

[0030] When the trip coil TC1 is energized, the circuit breaker Q0 trips, and the corresponding auxiliary contact S5 of the circuit breaker is reset. The normally open closed contact opens and becomes normally open, and the normally closed contact opens and becomes normally closed.

[0031] Circuit breaker Q0 is controlled to open and close via the closing coil CC and the opening coil TC1. When closing, the control circuit energizes the closing coil CC, driving circuit breaker Q0 to close; when opening, the opening coil TC1 is energized, and circuit breaker Q0 opens. To prevent accidental closing, an anti-pumping relay K0 is installed. When the system is in a state where closing is prohibited (e.g., protection action or interlocking conditions not met), the anti-pumping relay K0 is controlled to disconnect the closing circuit, preventing the closing coil CC from operating. The closing coil CC can only be energized when the anti-pumping relay K0 is released and the interlocking conditions are met, ensuring the safe and reliable operation of circuit breaker Q0.

[0032] It also includes the signal light HL3 and the dual-position relay K1;

[0033] The signal light HL3 and the dual-position relay K1 are respectively connected between the positive power supply +KM and the negative power supply -KM of the control circuit;

[0034] The dual-position relay K1 includes:

[0035] The first normally open contact is connected between the positive power supply +KM and the trip coil TC1 of circuit breaker Q0;

[0036] The first normally closed contact is connected at one end to the positive terminal of the test position switch S8 and working position switch S9 of the circuit breaker Q0 after being connected in parallel, and at the other end to the positive power supply +KM.

[0037] After the second normally open contact is connected in series with the signal light HL3, the second normally open contact and the signal light HL3 are connected together between the positive power supply +KM and the negative power supply -KM.

[0038] like Figure 1 , Figure 2 As shown, in some embodiments, the dual-position relay K1 includes 1-20 contacts, wherein the first normally open contacts are 7 and 14, the first normally closed contacts are 3 and 18, and the second normally open contacts are 8 and 13.

[0039] In some embodiments, the dual-position relay K1 includes an external actuating contact P14 that controls the operation of the internal coil of the dual-position relay K1.

[0040] The external operating contact P14 receives one or more input signals, which can be electrical signals from various protection devices, control switches, etc. The operation of the dual-position relay K1 is controlled by processing and transmitting the signals.

[0041] In some embodiments, the dual-position relay K1 includes a reset button FA for locking and resetting the dual-position relay K1.

[0042] Pressing the reset button FA will activate the internal relay of the dual-position relay K1, allowing the first normally open contact, the first normally closed contact, and the second normally open contact to return to their initial states. That is, the first normally open contact remains normally open, the first normally closed contact remains normally closed, and the second normally open contact remains normally open.

[0043] like Figure 1 As shown, the electrical fault interlocking steps are as follows:

[0044] Step 1: Upon receiving a fault signal via external action contact P14, the internal coil of the dual-position relay K1 is activated, causing the normally open contacts to close (first normally open contacts 7 and 14, and second normally open contacts 8 and 13 to close) and the normally closed contacts to open (first normally closed contacts 3 and 18 to open). The position state transition is controlled by the energization of the coil, and the dual-position relay K1 retains its last position state after power loss, thus having a memory function.

[0045] Step 2: The first normally open contacts 7 and 14 are closed, driving the trip coil TC1 to trip the circuit breaker Q0 until the circuit breaker Q0 is reliably disconnected.

[0046] Step 3: Open the first normally closed contacts 3 and 18 to disconnect the closing circuit, so that the closing coil CC in the circuit breaker Q0 cannot be energized in time, thus achieving the closing lockout function.

[0047] Step 4: When the second normally open contacts 8 and 13 close, the indicator light HL3 illuminates, indicating a fault operation, i.e., the double-position relay is activated.

[0048] Step 5: Reset circuit. If you want to close circuit breaker Q0 after the fault has been cleared, you must drive the reset button FA to lock and reset the double position relay K1 before you can allow circuit breaker Q0 to close. This prevents circuit breaker Q0 from being closed before the fault has been cleared and prevents the fault from spreading.

[0049] Through the above multiple logic judgments and controls, and the unique position holding and contact control functions of the dual-position relay K1, the circuit can be locked and protected through reasonable circuit design and signal control, preventing circuit malfunction when conditions are not met.

[0050] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by this utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An electrical fault interlocking circuit based on a dual-position relay, comprising a positive power supply +KM and a negative power supply -KM for the control circuit, and a circuit breaker Q0 connected between the positive power supply +KM and the negative power supply -KM for the control circuit, wherein, The test position switch S8, working position switch S9, and positive terminal of the trip coil TC1 of the circuit breaker Q0 are all connected to the positive power supply +KM. The negative terminal of the anti-pumping relay K0, closing coil CC, and trip coil TC1 of the circuit breaker Q0 are all connected to the negative power supply -KM. The circuit breaker Q0 is characterized by further including an indicator light HL3 and a dual-position relay K1. The signal light HL3 and the dual-position relay K1 are respectively connected between the positive power supply +KM and the negative power supply -KM of the control circuit; The dual-position relay K1 includes: The first normally open contact is connected between the positive power supply +KM and the trip coil TC1 of circuit breaker Q0; The first normally closed contact is connected at one end to the positive terminal of the test position switch S8 and working position switch S9 of the circuit breaker Q0 after being connected in parallel, and at the other end to the positive power supply +KM. After the second normally open contact is connected in series with the signal light HL3, the second normally open contact and the signal light HL3 are connected together between the positive power supply +KM and the negative power supply -KM.

2. An electrical fault lockout circuit based on a dual position relay according to claim 1, wherein, The dual-position relay K1 includes an external operating contact P14 that controls the operation of the internal coil of the dual-position relay K1.

3. The dual position relay based electrical fault lockout circuit of claim 1, wherein, The dual-position relay K1 includes a reset button FA for locking and resetting the dual-position relay K1.

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