A residual voltage detection module and device for power distribution lines

Abstract

This utility model discloses a residual voltage detection module and device for distribution network lines, relating to the field of residual voltage detection technology. It solves the technical problem of urgently needing a residual voltage detection circuit capable of quickly and reliably identifying residual voltage in distribution network lines and adapting to different power grid environments. The module includes, in sequence, an input control circuit, a residual voltage judgment circuit, a residual voltage blocking circuit, an isolation output circuit, and a residual voltage reset circuit. The input terminal of the input control circuit is connected to the first and second power supply circuits of the distribution terminal. The input control circuit controls the start or stop of the residual voltage detection module. The residual voltage judgment circuit detects the presence of a residual voltage signal in the distribution terminal. The residual voltage blocking circuit blocks the residual voltage signal. The isolation output circuit isolates and outputs the blocked residual voltage signal to the residual voltage reset circuit. The module provided by this utility model has high reliability, fast response speed, and can effectively adapt to complex and changing operating environments.

Description

Technical Field

[0001] This utility model relates to the field of residual voltage detection technology, and in particular to a residual voltage detection module and device for power distribution lines. Background Technology

[0002] During the operation of a distribution network, residual voltage may remain after a line is disconnected due to faults such as short circuits or grounding, for various reasons. This residual voltage may originate from the release of energy stored in the line's distributed capacitance and inductance, islanded operation or reverse feedback of distributed power sources (such as photovoltaic and energy storage systems), and electromagnetic induction from adjacent lines. Failure to detect and isolate residual voltage in a timely manner may pose a risk of electric shock to maintenance personnel, cause malfunctions in automatic reclosing, trigger secondary impacts on equipment, or cause asynchronous closing, threatening the safe and stable operation of the power grid.

[0003] Currently, residual voltage detection in power distribution networks mainly relies on software algorithms or electronic circuits, such as those based on microprocessors or digital signal processing algorithms, which involve steps like signal sampling, data processing, and logical judgment. Because it depends on software algorithms or microprocessor control, it leads to significant detection delays and weak resistance to electromagnetic interference, resulting in unreliable detection results. Furthermore, software solutions typically require regular maintenance and upgrades, increasing operational complexity and making them difficult to adapt to complex and changing operating environments.

[0004] In the process of developing this utility model, the applicant discovered at least the following problems in the prior art:

[0005] There is an urgent need for a residual voltage detection circuit that can quickly and reliably identify residual voltage in distribution network lines and adapt to different power grid environments. Utility Model Content

[0006] The purpose of this utility model is to provide a residual voltage detection module and device for distribution network lines, so as to solve the technical problem in the prior art of urgently needing a residual voltage detection circuit that can quickly and reliably identify the residual voltage of distribution network lines and adapt to different power grid environments. The various technical effects of the preferred technical solutions provided by this utility model are detailed below.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This utility model provides a residual voltage detection module for a power distribution network, comprising a switching control circuit, a residual voltage judgment circuit, a residual voltage blocking circuit, an isolation output circuit, and a residual voltage reset circuit connected in sequence. The input terminal of the switching control circuit is connected to a first power supply circuit and a second power supply circuit of the distribution terminal. The switching control circuit controls the start or stop of the residual voltage detection module. The residual voltage judgment circuit detects whether a residual voltage signal exists in the distribution terminal. The residual voltage blocking circuit blocks the residual voltage signal. The isolation output circuit isolates and outputs the blocked residual voltage signal to the residual voltage reset circuit. The reset circuit is used to reset the locked residual voltage signal; the input control circuit includes a double-pole double-throw monostable relay K2, a freewheeling diode D11, and a DC-DC power supply module U4; the first normally closed terminal and the second normally closed terminal of the double-pole double-throw monostable relay K2 are respectively connected to the first power supply circuit and the second power supply circuit; the positive and negative terminals of the coil of the double-pole double-throw monostable relay K2 are respectively connected to the positive and negative terminals of the power supply of the DC-DC power supply module U4; the freewheeling diode D11 is connected in parallel between the coil of the double-pole double-throw monostable relay K2 and the DC-DC power supply module U4.

[0009] Optionally, the residual voltage judgment circuit includes a first judgment unit and a second judgment unit; the first judgment unit includes a first voltage monitoring chip U2, diodes D2 and D6, Zener diodes D4 and D10, transistors Q1 and Q2, resistors R4 and R8; the input terminal of the first voltage monitoring chip U2 is connected to the first normally closed terminal of the double-pole double-throw monostable relay K2, and the output terminal is connected to the cathodes of diodes D2 and D6; the anode of diode D2 is connected to the cathode of the Zener diode D4 and the resistor R4. The first terminal of the diode D6 is connected to the first terminal of the resistor R8; the second terminal of the resistor R8 is connected to the second terminal of the resistor R4; the anode of the Zener diode D4 is connected to the base of the transistor Q1; the emitter of the transistor Q1 is grounded, and the collector is connected between the anode of the diode D6 and the first terminal of the resistor R8; the cathode of the Zener diode D10 is connected between the anode of the diode D6 and the first terminal of the resistor R8, and the anode is connected to the base of the transistor Q2; the emitter of the transistor Q2 is grounded, and the collector is connected to the base of the transistor Q1. The second judgment unit includes a second voltage monitoring chip U5, diodes D14 and D19, Zener diodes D12 and D18, transistor Q3 and Q4, resistors R11 and R16; the input terminal of the second voltage monitoring chip U5 is connected to the second normally closed terminal of the double-pole double-throw monostable relay K2, and the output terminal is connected to the cathodes of diodes D14 and D19; the anode of diode D19 is connected to the cathode of Zener diode D18 and the first terminal of resistor R16; the diodes D14 and D19 are also connected to the second normally closed terminal of the second voltage monitoring chip U5. The anode of the diode D14 is connected to the first terminal of the resistor R11; the second terminal of the resistor R11 is connected to the second terminal of the resistor R16; the anode of the Zener diode D18 is connected to the base of the transistor Q4; the emitter of the transistor Q4 is grounded, and the collector is connected between the anode of the diode D14 and the first terminal of the resistor R11; the cathode of the Zener diode D12 is connected between the anode of the diode D14 and the first terminal of the resistor R11, and the anode is connected to the base of the transistor Q3; the emitter of the transistor Q3 is grounded, and the collector is connected to the residual voltage blocking circuit.

[0010] Optionally, the residual voltage lockout circuit includes a first lockout unit and a second lockout unit; the first lockout unit includes a first magnetic latching relay K1, a diode D8, and a diode D9; the diode D8 is connected in parallel with the first operating coil of the first magnetic latching relay K1; the diode D9 is connected in parallel with the first reset coil of the first magnetic latching relay K1; the negative terminal of the first operating coil of the first magnetic latching relay K1 is connected to the collector of the transistor Q2; the negative terminal of the first reset coil of the first magnetic latching relay K1 is connected to the residual voltage reset circuit; the constant voltage of the first magnetic latching relay K1... The first magnetic latching relay K1 is connected to the isolated output circuit. The second latching unit includes a second magnetic latching relay K3, a diode D15, and a diode D16. The diode D15 is connected in parallel with the second operating coil of the second magnetic latching relay K3. The diode D16 is connected in parallel with the second reset coil of the second magnetic latching relay K3. The negative terminal of the second operating coil of the second magnetic latching relay K3 is connected to the collector of the transistor Q3. The negative terminal of the second reset coil of the second magnetic latching relay K3 is connected to the residual voltage reset circuit. The normally open terminal of the first magnetic latching relay K1 is connected to the isolated output circuit.

[0011] Optionally, the isolated output circuit includes a first output unit and a second output unit; the first output unit includes a first optocoupler U1, resistor R3, resistor R1, capacitor C3, and capacitor C4; the primary side of the first optocoupler U1 is connected to the normally open terminal of the first magnetic latching relay K1 through resistor R3, and the secondary side outputs a first residual voltage signal; capacitor C3 is connected to the primary side of the first optocoupler U1; resistor R1 and capacitor C4 are connected in series on the secondary side of the first optocoupler U1; the second output unit includes a second optocoupler U6, resistor R17, resistor R15, capacitor C13, and capacitor C14; the primary side of the second optocoupler U6 is connected to the normally open terminal of the second magnetic latching relay K3 through resistor R17, and the secondary side outputs a second residual voltage signal; capacitor C13 is connected to the primary side of the second optocoupler U6; resistor R15 and capacitor C14 are connected in series on the secondary side of the second optocoupler U6.

[0012] Optionally, the residual voltage recovery circuit includes a third optocoupler U3, capacitor C7, capacitor C8, and inductor L1; the primary side of the third optocoupler U3 is connected to the recovery signal through capacitor C7, capacitor C8, and inductor L1, and the secondary side is connected between the first locking unit and the second locking unit.

[0013] Optionally, the module further includes a surge protection circuit disposed between the power supply circuit and the input control circuit; the surge protection circuit includes a fuse F1, a varistor RV1, a resistor R5, a fuse F2, a varistor RV2, and a resistor R14; the first end of the fuse F1 is connected to the live wire L1 of the first power supply circuit, and the second end is connected to the first end of the varistor RV1; the second end of the varistor RV1 is connected to the second end of the resistor R5; the first end of the resistor R5 is connected to the neutral wire N1 of the second power supply circuit; the second end of the resistor R5 is also connected to the first normally closed terminal of the double-pole double-throw monostable relay K2; the first end of the fuse F2 is connected to the neutral wire N2 of the second power supply circuit, and the second end is connected to the first end of the varistor RV2; the second end of the varistor RV2 is connected to the second end of the resistor R14; the first end of the resistor R14 is connected to the live wire L2 of the second power supply circuit; the second end of the resistor R14 is also connected to the second normally closed terminal of the double-pole double-throw monostable relay K2.

[0014] Optionally, the module further includes a rectifier and voltage regulator circuit disposed between the input control circuit and the residual voltage judgment circuit; the rectifier and voltage regulator circuit includes a first full-bridge rectifier unit and a second full-bridge rectifier unit; the first full-bridge rectifier unit includes a diode full-bridge D1, a capacitor C1, and a Zener diode D3; the input terminal of the diode full-bridge D1 is connected to the live wire L1 and the neutral wire N1 of the first power supply circuit; the positive terminal of the output terminal of the diode full-bridge D1 is connected to the residual voltage judgment circuit, and the negative terminal of the output terminal is grounded; the capacitor C1 and the Zener diode D3... A voltage regulator diode D3 is connected in parallel between the positive and negative terminals of the output terminal of the full-bridge diode D1; the second full-bridge rectifier unit includes a full-bridge diode D21, a capacitor C12, and a voltage regulator diode D20; the input terminal of the full-bridge diode D21 is connected to the live wire L2 and the neutral wire N2 of the second power supply circuit; the positive terminal of the output terminal of the full-bridge diode D21 is connected to the residual voltage judgment circuit, and the negative terminal of the output terminal is grounded; the capacitor C12 and the voltage regulator diode D20 are connected in parallel between the positive and negative terminals of the output terminal of the full-bridge diode D1.

[0015] Optionally, the rectifier and voltage regulator circuit further includes a first half-wave rectifier unit and a second half-wave rectifier unit; the first half-wave rectifier unit includes a diode D7, capacitors C5 and C6, and a Zener diode D5; the anode of the diode D7 is connected to the first normally closed terminal of the double-pole double-throw monostable relay K2, and the cathode is grounded through capacitors C5 and C6; the cathode of the diode D7 is also connected to the residual voltage judgment circuit; the cathode of the Zener diode D5 is connected between the cathode of the diode D7 and the residual voltage judgment circuit, and the anode is grounded; the second half-wave rectifier unit includes a diode D13, capacitors C9 and C10, and a Zener diode D17; the anode of the diode D13 is connected to the second normally closed terminal of the double-pole double-throw monostable relay K2, and the cathode is grounded through capacitors C9 and C10; the cathode of the diode D13 is also connected to the residual voltage judgment circuit; the cathode of the Zener diode D17 is connected between the cathode of the diode D13 and the residual voltage judgment circuit, and the anode is grounded.

[0016] Optionally, the module further includes a resistor-capacitor (RC) step-down circuit disposed between the input control circuit and the rectifier-regulator circuit; the RC step-down circuit includes a resistor R2, a capacitor C2, a resistor R18, and a capacitor C11; the resistor R2 and the capacitor C2 are connected in parallel between the first normally closed terminal of the double-pole double-throw monostable relay K2 and the input terminal of the diode full-bridge D1; the resistor R18 and the capacitor C11 are connected in parallel between the second normally closed terminal of the double-pole double-throw monostable relay K2 and the input terminal of the diode full-bridge D21.

[0017] A residual voltage detection device includes a residual voltage detection module for a power distribution line as described above.

[0018] Implementing one of the above-described technical solutions of this utility model has the following advantages or beneficial effects:

[0019] The residual voltage detection module provided by this utility model is a residual voltage detection implemented by a pure hardware circuit and has a lockout to maintain the output. It does not require software programming, has higher reliability, and because it is a pure hardware circuit, it has a faster response speed and stronger anti-electromagnetic interference capability. It can effectively adapt to complex and ever-changing operating environments and reduce maintenance costs. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0021] Figure 1This is a circuit diagram of the residual voltage detection module for a power distribution network line according to Embodiment 1 of this utility model;

[0022] In the diagram: 1. Input control circuit; 2. Residual voltage judgment circuit; 3. Residual voltage lockout circuit; 4. Isolation output circuit; 5. Residual voltage reset circuit; 6. Surge protection circuit; 7. Rectifier and voltage regulator circuit; 8. RC step-down circuit. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, various exemplary embodiments described below will be referenced to the accompanying drawings, which form part of the exemplary embodiments, illustrating various exemplary embodiments that may be adopted to implement this utility model. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. It should be understood that they are merely examples of processes, methods, and apparatuses consistent with some aspects of this utility model disclosed as detailed in the appended claims, and other embodiments may be used, or structural and functional modifications may be made to the embodiments listed herein without departing from the scope and spirit of this utility model.

[0024] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," etc., indicate the orientation or positional relationship based on the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the referred element must have a specific orientation, or be constructed and operated in a specific orientation. The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. The term "multiple" means two or more. The terms "connected" and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, integral connections, mechanical connections, electrical connections, communication connections, direct connections, indirect connections through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more of the related listed items. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0025] To illustrate the technical solution described in this utility model, specific embodiments are described below, showing only the parts related to the embodiments of this utility model.

[0026] Example 1:

[0027] like Figure 1As shown, this utility model provides a residual voltage detection module for a power distribution network line, including an input control circuit 1, a residual voltage judgment circuit 2, a residual voltage blocking circuit 3, an isolation output circuit 4, and a residual voltage reset circuit 5 connected in sequence; the input terminal of the input control circuit 1 is connected to the first power supply circuit and the second power supply circuit of the power distribution terminal; each circuit works together through logical relationships and electrical connections to ensure that the system can operate stably under various conditions, while protecting the safety of personnel and equipment.

[0028] The input control circuit 1 controls the start or stop of the residual voltage detection module; it determines whether to start residual voltage detection based on external signals or internal logic. The residual voltage judgment circuit 2 detects the presence of residual voltage signals in the distribution terminal; by monitoring these signals, the circuit can determine when it is safe to proceed with the next operation, such as disconnecting or reconnecting the circuit. The residual voltage blocking circuit 3 blocks the residual voltage signal; when residual voltage is detected, this circuit blocks the signal to prevent safety accidents caused by residual voltage and increase the safety of the distribution terminal. The isolation output circuit 4 isolates and outputs the blocked residual voltage signal to the residual voltage reset circuit 5 to protect the internal circuit from external interference or damage, providing a safe interface for safe interaction with other devices or systems; the residual voltage reset circuit 5 resets the blocked signal to ensure normal operation after residual voltage processing.

[0029] The residual voltage detection module provided in this embodiment is a pure hardware circuit for residual voltage detection and lockout to maintain output. It does not require software programming, has higher reliability, and because it is a pure hardware circuit, it has a faster response speed and stronger anti-electromagnetic interference capability. It can effectively adapt to complex and ever-changing operating environments and reduce maintenance costs.

[0030] As an optional implementation, the input control circuit 1 includes a double-pole double-throw monostable relay K2, a freewheeling diode D11, and a DC-DC power module U4; preferably, the DC-DC power module U4 is model B0512S-1WR3. The first normally closed terminal (pin 1) and the second normally closed terminal (pin 3) of the double-pole double-throw monostable relay K2 are respectively connected to the first power supply circuit and the second power supply circuit. Specifically, the first normally closed terminal (pin 1) is connected to the live wire L1 and the neutral wire N1 of the first power supply circuit; the second normally closed terminal (pin 3) is connected to the live wire L2 and the neutral wire N2 of the second power supply circuit. The positive and negative terminals of the coil of the double-pole double-throw monostable relay K2 are respectively connected to the positive power supply terminal (pin 4) and the negative power supply terminal (pin 3) of the DC-DC power module U4; the DC-DC power module U4 provides a 12V AC voltage to the coil of the double-pole double-throw monostable relay K2. The freewheeling diode D11 is connected in parallel between the coil of the double-pole double-throw monostable relay K2 and the DC-DC power module U4. Specifically, the cathode of the freewheeling diode D11 is connected to the positive terminal of the DC-DC power module U4, and the anode is connected to the negative terminal of the DC-DC power module U4, in order to protect the normally closed contact of the double-pole double-throw monostable relay K2 from being broken down.

[0031] When a power distribution network trips due to a short circuit, grounding, or other fault, the AC power supply to the distribution terminal is cut off. All levels of power supply in the distribution terminal (including the 5V power supply provided to the residual voltage detection module) stop outputting. There is no voltage output at the output terminal of the DC-DC power module U4. There is no voltage on the coil of the double-pole double-throw monostable relay K2. The two normally closed contacts of the double-pole double-throw monostable relay K2 are closed by default, which connects the power supply circuit of the upstream distribution terminal and the downstream circuit, and controls the start of the residual voltage detection.

[0032] Under normal power supply conditions, the distribution terminal operates normally and does not require residual voltage detection. Furthermore, all power supplies at each level of the distribution terminal (including the 5V power supply provided to the residual voltage detection module) are normal. The DC-DC power module U4 outputs a 12V AC voltage, which is applied to the coil of the double-pole double-throw monostable relay K2. The two normally closed contacts of the double-pole double-throw monostable relay K2 switch to normally open contacts, disconnecting the downstream circuit from the upstream power supply circuit and exiting the residual voltage detection.

[0033] As an optional implementation, the residual voltage judgment circuit 2 includes a first judgment unit and a second judgment unit; the first judgment unit includes a first voltage monitoring chip U2, diodes D2 and D6, Zener diodes D4 and D10, transistors Q1 and Q2, resistors R4 and R8; the input terminal (pin 2) of the first voltage monitoring chip U2 is connected to the first normally closed terminal (pin 2) of the double-pole double-throw monostable relay K2, and the output terminal is connected to the cathodes of diodes D2 and D6; the anode of diode D2 is connected to the Zener diode. The cathode of diode D4 is connected to the first terminal of resistor R4; the anode of diode D6 is connected to the first terminal of resistor R8; the second terminal of resistor R8 is connected to the second terminal of resistor R4; the anode of Zener diode D4 is connected to the base of transistor Q1; the emitter of transistor Q1 is grounded, and the collector is connected between the anode of diode D6 and the first terminal of resistor R8; the cathode of Zener diode D10 is connected between the anode of diode D6 and the first terminal of resistor R8, and the anode is connected to the base of transistor Q2; the emitter of transistor Q2 is grounded, and the collector is connected to residual voltage blocking circuit 3.

[0034] The second judgment unit includes a second voltage monitoring chip U5, diodes D14 and D19, Zener diodes D12 and D18, transistor Q3 and Q4, resistors R11 and R16; the input terminal of the second voltage monitoring chip U5 is connected to the second normally closed terminal (pin 4) of the double-pole double-throw monostable relay K2, and the output terminal is connected to the cathodes of diodes D14 and D19; the anode of diode D19 is connected to the cathode of Zener diode D18 and the first terminal of resistor R16; diodes... The anode of D14 is connected to the first terminal of resistor R11; the second terminal of resistor R11 is connected to the second terminal of resistor R16; the anode of Zener diode D18 is connected to the base of transistor Q4; the emitter of transistor Q4 is grounded, and the collector is connected between the anode of diode D14 and the first terminal of resistor R11; the cathode of Zener diode D12 is connected between the anode of diode D14 and the first terminal of resistor R11, and the anode is connected to the base of transistor Q3; the emitter of transistor Q3 is grounded, and the collector is connected to residual voltage blocking circuit 3.

[0035] When the amplitude of the voltage signal output by the current stage input control circuit 1 is lower than the reference voltage value built into the voltage monitoring chip U2 (indicating that there is no residual voltage signal in the circuit at this time), the voltage detection chip U2 outputs a low level, diodes D2 and D6 are forward-biased, Zener diodes D4 and D10 are reverse-biased and cut off, transistors Q1 and Q2 are cut off, and the collector of transistor Q2 is disconnected from the 12V1- ground line, indicating that the first judgment unit has not detected a residual voltage signal. When the amplitude of the voltage signal output by the current stage input control circuit 1 is higher than the reference voltage value built into the voltage monitoring chip U2 (indicating that there is a residual voltage signal at this time), the voltage detection chip U2 outputs a high level, diodes D2 and D6 are cut off, Zener diodes D4 and D10 are reverse-biased and broken down, transistors Q1 and Q2 are saturated and conduct, and the collector of transistor Q2 is connected to the 12V1- ground line, indicating that the first judgment unit has detected a residual voltage signal. The working principle of the second judgment unit is the same as that of the first judgment unit, and will not be described again here.

[0036] As an optional implementation, the residual voltage lockout circuit 3 includes a first lockout unit and a second lockout unit; the first lockout unit includes a first magnetic latching relay K1, a diode D8, and a diode D9; diode D8 is connected in parallel with the first operating coil of the first magnetic latching relay K1; diode D9 is connected in parallel with the first reset coil of the first magnetic latching relay K1; the negative terminal of the first operating coil of the first magnetic latching relay K1 is connected to the collector of transistor Q2; the negative terminal of the first reset coil of the first magnetic latching relay K1 is connected to the residual voltage reset circuit 5; the normally open terminal of the first magnetic latching relay K1 is connected to the isolation output circuit 4.

[0037] The second locking unit includes a second magnetic latching relay K3, diode D15, and diode D16; diode D15 is connected in parallel with the second operating coil of the second magnetic latching relay K3; diode D16 is connected in parallel with the second reset coil of the second magnetic latching relay K3; the negative terminal of the second operating coil of the second magnetic latching relay K3 is connected to the collector of transistor Q3; the negative terminal of the second reset coil of the second magnetic latching relay K3 is connected to the residual voltage reset circuit 5; the normally open terminal of the first magnetic latching relay K1 is connected to the isolation output circuit 4.

[0038] Diodes D8 and D15 are connected in reverse parallel to the two ends of the operating coil of the first magnetic latching relay K1 and the two ends of the operating coil of the second magnetic latching relay K3, respectively. Diodes D9 and D16 are connected in reverse parallel to the two ends of the reset coil of the first magnetic latching relay K1 and the two ends of the reset coil of the second magnetic latching relay K3, respectively, to serve as the operating coil for freewheeling protection. The positive terminals of the operating coils of the first magnetic latching relay K1 and the second magnetic latching relay K3 are connected to the 12V1+ and 12V2+ voltages output by the rectifier and voltage regulator circuit 7, respectively. The positive terminals of the reset coils of the two magnetic latching relays are connected to the 12V+ power supply provided by the DC-DC power module U4, respectively. The common terminal (pin 4) of the contacts of the two magnetic latching relays is connected to the 12V+ power supply provided by the DC-DC power module U4, and the normally open terminal (pin 5) is connected to the input terminals of the first optocoupler U1 and optocoupler U6 of the isolation output circuit 4, respectively. The negative terminals of the operating coils of the two magnetic latching relays are connected to the collectors of transistors Q2 and Q3 in the residual voltage judgment circuit 2, respectively. When any judgment unit (first judgment unit or second judgment unit) or both judgment units (first judgment unit and second judgment unit) in the residual voltage judgment circuit 2 judges that there is a residual voltage signal, transistors Q2 or Q3 or both transistors Q2 and Q3 in the circuit are simultaneously saturated and turned on, and the operating coils of the corresponding magnetic latching relays are energized and held. The normally open terminals (pin 5) of the two magnetic latching relays are changed from normally open to closed and latched, thereby achieving the latching and holding of the residual voltage signal.

[0039] As an optional implementation, the isolated output circuit 4 includes a first output unit and a second output unit; the first output unit includes a first optocoupler U1, resistor R3, resistor R1, capacitor C3, and capacitor C4; the primary side of the first optocoupler U1 is connected to the normally open terminal of the first magnetic latching relay K1 through resistor R3, and the secondary side outputs a first residual voltage signal; capacitor C3 is connected to the primary side of the first optocoupler U1; resistor R1 and capacitor C4 are connected in series on the secondary side of the first optocoupler U1; the second output unit includes a second optocoupler U6, resistor R17, resistor R15, capacitor C13, and capacitor C14; the primary side of the second optocoupler U6 is connected to the normally open terminal of the second magnetic latching relay K3 through resistor R17, and the secondary side outputs a second residual voltage signal; capacitor C13 is connected to the primary side of the second optocoupler U6; resistor R15 and capacitor C14 are connected in series on the secondary side of the second optocoupler U6.

[0040] After the normally open terminals (pin 5) of the two magnetic latching relays in the residual voltage lockout circuit 3 change from normally open to closed and lockout, the 12V voltage is connected to the primary side (one side of the light-emitting diode) of the first optocoupler U1 and the second optocoupler U6 through resistors R3 and R1 respectively, forming a current path with the 12V-ground line. The secondary side (one side of the phototransistor) of the first optocoupler U1 and the second optocoupler U6 is saturated and conducting. Thus, the locked residual voltage signal is isolated and output to the residual voltage reset circuit 5 through the first optocoupler U1 and the second optocoupler U6. The isolated output first residual voltage signal CY_L1N1 and second residual voltage signal CY_L2N2 change from the high level when there is no residual voltage to the low level.

[0041] As an optional implementation, the residual voltage reset circuit 5 includes a third optocoupler U3, capacitors C7 and C8, and inductor L1. The primary side of the third optocoupler U3 is connected to the reset signal via capacitors C7, C8, and inductor L1, and the secondary side is connected between the first and second locking units. The 5V+ voltage from the external power distribution terminal passes through the filter circuit composed of capacitors C7, C8, and inductor L1 and enters the first primary side (anode of the light-emitting diode) of the third optocoupler U3. The reset signal RESET from the external power distribution terminal is connected to the second primary side (cathode of the light-emitting diode) of the third optocoupler U3. The first secondary side (collector of the phototransistor) of the third optocoupler U3 is connected to the negative terminal (pin 7) of the reset coil of the first and second magnetic latching relays K1 and K3 in the residual voltage lockout circuit 3. The second secondary side (emitter of the phototransistor) of the third optocoupler U3 is connected to the 12V- ground line. By default, the reset signal RESET is high, and the secondary side of the third optocoupler U3 is cut off. When the power distribution line resumes normal power supply, and it is necessary to reset the locked residual voltage signal, the power distribution terminal changes the reset signal RESET to low. The secondary side of the third optocoupler U3 is saturated and conducts. The 12V+ and 12V- of the reset coils of the two magnetic latching relays in the residual voltage locking circuit 3 form a current loop. The locked contact (pin 5) resets and opens. The first residual voltage signal CY_L1N1 and the second residual voltage signal CY_L2N2 change from the low level of the lockout when there is residual voltage to the high level when there is no residual voltage, thus completing the reset.

[0042] As an optional implementation, the module further includes a surge protection circuit 6 disposed between the power supply circuit and the input control circuit 1; the surge protection circuit 6 includes a fuse F1, a varistor RV1, a resistor R5, a fuse F2, a varistor RV2, and a resistor R14; the first end of the fuse F1 is connected to the live wire L1 of the first power supply circuit, and the second end is connected to the first end of the varistor RV1; the second end of the varistor RV1 is connected to the second end of the resistor R5; the first end of the resistor R5 is connected to the neutral wire N1 of the second power supply circuit; the second end of the resistor R5 is also connected to the first normally closed terminal of the double-pole double-throw monostable relay K2; the first end of the fuse F2 is connected to the neutral wire N2 of the second power supply circuit, and the second end is connected to the first end of the varistor RV2; the second end of the varistor RV2 is connected to the second end of the resistor R14; the first end of the resistor R14 is connected to the live wire L2 of the second power supply circuit; the second end of the resistor R14 is also connected to the second normally closed terminal of the double-pole double-throw monostable relay K2. Fuse F1 and F2 provide overcurrent protection in the circuit, varistors RV1 and RV2 suppress surge voltage, and resistors R5 and R14 limit current.

[0043] As an alternative implementation, the module also includes a rectifier and voltage regulator circuit 7 disposed between the input control circuit 1 and the residual voltage judgment circuit 2; the rectifier and voltage regulator circuit 7 includes a first full-bridge rectifier unit and a second full-bridge rectifier unit.

[0044] The first full-bridge rectifier unit includes a full-bridge diode D1, a capacitor C1, and a Zener diode D3. The input terminal of the full-bridge diode D1 is connected to the live wire L1 and the neutral wire N1 of the first power supply circuit. The positive terminal of the output terminal of the full-bridge diode D1 is connected to the residual voltage judgment circuit 2, and the negative terminal of the output terminal is grounded. The capacitor C1 and the Zener diode D3 are connected in parallel between the positive and negative terminals of the output terminal of the full-bridge diode D1. The second full-bridge rectifier unit includes a full-bridge diode D21, a capacitor C12, and a Zener diode D20. The input terminal of the full-bridge diode D21 is connected to the live wire L2 and the neutral wire N2 of the second power supply circuit. The positive terminal of the output terminal of the full-bridge diode D21 is connected to the residual voltage judgment circuit 2, and the negative terminal of the output terminal is grounded. The capacitor C12 and the Zener diode D20 are connected in parallel between the positive and negative terminals of the output terminal of the full-bridge diode D1. These two rectifier units rectify the power supply from the DC-DC power module U4 into 12V1 and 12V2 voltages, and then output them to the residual voltage judgment circuit 2 and the residual voltage blocking circuit 3.

[0045] As an optional implementation, the rectifier and voltage regulator circuit 7 further includes a first half-wave rectifier unit and a second half-wave rectifier unit; the first half-wave rectifier unit includes a diode D7, capacitors C5 and C6, and a Zener diode D5; the anode of diode D7 is connected to the first normally closed terminal of a double-pole double-throw monostable relay K2, and the cathode is grounded through capacitors C5 and C6; the cathode of diode D7 is also connected to the residual voltage judgment circuit 2; the cathode of Zener diode D5 is connected between the cathode of diode D7 and the residual voltage judgment circuit 2, and the anode is grounded; the second half-wave rectifier unit includes a diode D13, capacitors C9 and C10, and a Zener diode D17; the anode of diode D13 is connected to the second normally closed terminal of a double-pole double-throw monostable relay K2, and the cathode is grounded through capacitors C9 and C10; the cathode of diode D13 is also connected to the residual voltage judgment circuit 2; the cathode of Zener diode D17 is connected between the cathode of diode D13 and the residual voltage judgment circuit 2, and the anode is grounded. The output voltage amplitude of these two rectifier units depends on the magnitude of the residual voltage signal in the preceding circuit. This is used to detect and judge the residual voltage signal in the following circuit. Zener diode D5 and Zener diode D17 act as residual voltage amplitude clamps to prevent the residual voltage amplitude from being too high and damaging the subsequent residual voltage detection and judgment circuit.

[0046] As an optional implementation, the module further includes a resistor-capacitor (RC) step-down circuit 8 disposed between the input control circuit 1 and the rectifier-regulator circuit 7. The RC step-down circuit 8 includes a resistor R2, a capacitor C2, a resistor R18, and a capacitor C11. Resistor R2 and capacitor C2 are connected in parallel between the first normally closed terminal of the double-pole double-throw monostable relay K2 and the input terminal of the diode full-bridge D1. Resistor R18 and capacitor C11 are connected in parallel between the second normally closed terminal of the double-pole double-throw monostable relay K2 and the input terminal of the diode full-bridge D21. The capacitive reactance generated by capacitors C2 and C11 under a certain frequency AC residual voltage signal is used to limit the maximum residual voltage current. Resistors R2 and R18 are bleeder resistors, whose function is to ensure that the charge on capacitors C2 and C11 is discharged within a specified time.

[0047] The embodiment is merely a special case and does not indicate that this utility model is implemented in such a way.

[0048] Example 2:

[0049] The difference between this second embodiment and the first embodiment is that the second embodiment provides a residual voltage detection device, including a residual voltage detection module for a power distribution line as described in any of the embodiments in the first embodiment. The device in this embodiment is implemented using the residual voltage detection module described in the first embodiment. It achieves residual voltage detection through pure hardware circuitry and maintains the output with a lockout mechanism, eliminating the need for software programming. This results in higher reliability, faster response speed, stronger resistance to electromagnetic interference, and effective adaptation to complex and changing operating environments, thus reducing maintenance costs.

[0050] The above description is merely a preferred embodiment of the present utility model. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present utility model. Furthermore, under the teachings of the present utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present utility model. Therefore, the present utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present utility model.

Claims

1. A residual voltage detection module for a power distribution network line, characterized by, It includes a power-on control circuit, a residual voltage judgment circuit, a residual voltage blocking circuit, an isolation output circuit, and a residual voltage reset circuit connected in sequence; the input terminal of the power-on control circuit is connected to the first power supply circuit and the second power supply circuit of the power distribution terminal. The input control circuit is used to control the start or stop of the residual voltage detection module; the residual voltage judgment circuit is used to detect whether there is a residual voltage signal in the power distribution terminal; the residual voltage blocking circuit is used to block the residual voltage signal; the isolation output circuit is used to isolate and output the blocked residual voltage signal to the residual voltage reset circuit; the residual voltage reset circuit is used to reset the blocked residual voltage signal. The input control circuit includes a double-pole double-throw monostable relay K2, a freewheeling diode D11, and a DC-DC power module U4; the first normally closed terminal and the second normally closed terminal of the double-pole double-throw monostable relay K2 are respectively connected to the first power supply circuit and the second power supply circuit; the positive and negative terminals of the coil of the double-pole double-throw monostable relay K2 are respectively connected to the positive and negative terminals of the power supply of the DC-DC power module U4; the freewheeling diode D11 is connected in parallel between the coil of the double-pole double-throw monostable relay K2 and the DC-DC power module U4.

2. The residual voltage detection module for a power distribution network line according to claim 1, characterized in that, The residual voltage determination circuit includes a first determination unit and a second determination unit; The first judgment unit includes a first voltage monitoring chip U2, diodes D2 and D6, Zener diodes D4 and D10, transistors Q1 and Q2, resistors R4 and R8; the input terminal of the first voltage monitoring chip U2 is connected to the first normally closed terminal of the double-pole double-throw monostable relay K2, and the output terminal is connected to the cathodes of diodes D2 and D6; the anode of diode D2 is connected to the cathode of Zener diode D4 and the first terminal of resistor R4; the anode of diode D6 is connected to... The first terminal of resistor R8 is connected; the second terminal of resistor R8 is connected to the second terminal of resistor R4; the anode of Zener diode D4 is connected to the base of transistor Q1; the emitter of transistor Q1 is grounded, and the collector is connected between the anode of diode D6 and the first terminal of resistor R8; the cathode of Zener diode D10 is connected between the anode of diode D6 and the first terminal of resistor R8, and the anode is connected to the base of transistor Q2; the emitter of transistor Q2 is grounded, and the collector is connected to the residual voltage blocking circuit. The second judgment unit includes a second voltage monitoring chip U5, diodes D14 and D19, Zener diodes D12 and D18, transistors Q3 and Q4, resistors R11 and R16; the input terminal of the second voltage monitoring chip U5 is connected to the second normally closed terminal of the double-pole double-throw monostable relay K2, and the output terminal is connected to the cathodes of diodes D14 and D19; the anode of diode D19 is connected to the cathode of Zener diode D18 and the first terminal of resistor R16; the anode of diode D14... The first terminal of resistor R11 is connected; the second terminal of resistor R11 is connected to the second terminal of resistor R16; the anode of Zener diode D18 is connected to the base of transistor Q4; the emitter of transistor Q4 is grounded, and the collector is connected between the anode of diode D14 and the first terminal of resistor R11; the cathode of Zener diode D12 is connected between the anode of diode D14 and the first terminal of resistor R11, and the anode is connected to the base of transistor Q3; the emitter of transistor Q3 is grounded, and the collector is connected to the residual voltage blocking circuit.

3. The residual voltage detection module of a power distribution network circuit according to claim 2, characterized in that, The residual pressure interlocking circuit includes a first interlocking unit and a second interlocking unit; The first locking unit includes a first magnetic latching relay K1, a diode D8, and a diode D9; the diode D8 is connected in parallel with the first operating coil of the first magnetic latching relay K1; the diode D9 is connected in parallel with the first reset coil of the first magnetic latching relay K1; the negative terminal of the first operating coil of the first magnetic latching relay K1 is connected to the collector of the transistor Q2; the negative terminal of the first reset coil of the first magnetic latching relay K1 is connected to the residual voltage reset circuit; the normally open terminal of the first magnetic latching relay K1 is connected to the isolation output circuit. The second latching unit includes a second magnetic latching relay K3, diode D15, and diode D16; diode D15 is connected in parallel with the second operating coil of the second magnetic latching relay K3; diode D16 is connected in parallel with the second reset coil of the second magnetic latching relay K3; the negative terminal of the second operating coil of the second magnetic latching relay K3 is connected to the collector of transistor Q3; the negative terminal of the second reset coil of the second magnetic latching relay K3 is connected to the residual voltage reset circuit; the normally open terminal of the first magnetic latching relay K1 is connected to the isolation output circuit.

4. The residual voltage detection module of a power distribution network circuit according to claim 3, characterized in that, The isolated output circuit includes a first output unit and a second output unit; The first output unit includes a first optocoupler U1, resistors R3 and R1, capacitors C3 and C4; the primary side of the first optocoupler U1 is connected to the normally open terminal of the first magnetic latching relay K1 through resistor R3, and the secondary side outputs a first residual voltage signal; capacitor C3 is connected to the primary side of the first optocoupler U1; resistors R1 and capacitor C4 are connected in series on the secondary side of the first optocoupler U1. The second output unit includes a second optocoupler U6, resistors R17 and R15, and capacitors C13 and C14. The primary side of the second optocoupler U6 is connected to the normally open terminal of the second magnetic latching relay K3 through resistor R17, and the secondary side outputs a second residual voltage signal. The capacitor C13 is connected to the primary side of the second optocoupler U6. The resistor R15 and capacitor C14 are connected in series on the secondary side of the second optocoupler U6.

5. The residual voltage detection module of a power distribution network circuit according to claim 3, characterized in that, The residual voltage recovery circuit includes a third optocoupler U3, capacitor C7, capacitor C8, and inductor L1; the primary side of the third optocoupler U3 is connected to the recovery signal through capacitor C7, capacitor C8, and inductor L1, and the secondary side is connected between the first locking unit and the second locking unit.

6. The residual voltage detection module for a power distribution network circuit of claim 1, wherein, The module also includes a surge protection circuit disposed between the power supply circuit and the input control circuit; The surge protection circuit includes a fuse F1, a varistor RV1, a resistor R5, a fuse F2, a varistor RV2, and a resistor R14. The first end of fuse F1 is connected to the live wire L1 of the first power supply circuit, and the second end is connected to the first end of the varistor RV1. The second end of the varistor RV1 is connected to the second end of the resistor R5. The first end of the resistor R5 is connected to the neutral wire N1 of the second power supply circuit. The second end of the resistor R5 is also connected to the first normally closed terminal of the double-pole double-throw monostable relay K2. The first end of fuse F2 is connected to the neutral wire N2 of the second power supply circuit, and the second end is connected to the first end of the varistor RV2. The second end of the varistor RV2 is connected to the second end of the resistor R14. The first end of resistor R14 is connected to the live wire L2 of the second power supply circuit. The second end of resistor R14 is also connected to the second normally closed terminal of the double-pole double-throw monostable relay K2.

7. The residual voltage detection module for a power distribution network line according to claim 6, characterized in that, The module further includes a rectifier and voltage regulator circuit disposed between the input control circuit and the residual voltage judgment circuit; the rectifier and voltage regulator circuit includes a first full-bridge rectifier unit and a second full-bridge rectifier unit. The first full-bridge rectifier unit includes a full-bridge diode D1, a capacitor C1, and a Zener diode D3; the input terminal of the full-bridge diode D1 is connected to the live wire L1 and the neutral wire N1 of the first power supply circuit; the positive terminal of the output terminal of the full-bridge diode D1 is connected to the residual voltage judgment circuit, and the negative terminal of the output terminal is grounded; the capacitor C1 and the Zener diode D3 are connected in parallel between the positive and negative terminals of the output terminal of the full-bridge diode D1. The second full-bridge rectifier unit includes a full-bridge diode D21, a capacitor C12, and a Zener diode D20; the input terminal of the full-bridge diode D21 is connected to the live wire L2 and the neutral wire N2 of the second power supply circuit; the positive terminal of the output terminal of the full-bridge diode D21 is connected to the residual voltage judgment circuit, and the negative terminal of the output terminal is grounded; the capacitor C12 and the Zener diode D20 are connected in parallel between the positive and negative terminals of the output terminal of the full-bridge diode D1.

8. The residual voltage detection module for a power distribution network line according to claim 7, characterized in that, The rectifier and voltage regulator circuit also includes a first half-wave rectifier unit and a second half-wave rectifier unit; The first half-wave rectifier unit includes a diode D7, capacitors C5 and C6, and a Zener diode D5; the anode of the diode D7 is connected to the first normally closed terminal of the double-pole double-throw monostable relay K2, and the cathode is grounded through capacitors C5 and C6; the cathode of the diode D7 is also connected to the residual voltage detection circuit; the cathode of the Zener diode D5 is connected between the cathode of the diode D7 and the residual voltage detection circuit, and the anode is grounded. The second half-wave rectifier unit includes a diode D13, capacitors C9 and C10, and a Zener diode D17. The anode of the diode D13 is connected to the second normally closed terminal of the double-pole double-throw monostable relay K2, and the cathode is grounded through capacitors C9 and C10. The cathode of the diode D13 is also connected to the residual voltage detection circuit. The cathode of the Zener diode D17 is connected between the cathode of the diode D13 and the residual voltage detection circuit, and the anode is grounded.

9. The residual voltage detection module for a power distribution network line according to claim 7, characterized in that, The module further includes a resistor-capacitor (RC) step-down circuit disposed between the input control circuit and the rectifier-regulator circuit; the RC step-down circuit includes a resistor R2, a capacitor C2, a resistor R18, and a capacitor C11; the resistor R2 and the capacitor C2 are connected in parallel between the first normally closed terminal of the double-pole double-throw monostable relay K2 and the input terminal of the diode full-bridge D1; the resistor R18 and the capacitor C11 are connected in parallel between the second normally closed terminal of the double-pole double-throw monostable relay K2 and the input terminal of the diode full-bridge D21.

10. A residual pressure detection device, characterized in that, The residual voltage detection module for a power distribution line as described in any one of claims 1-9 is included.

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