Trip control circuit and residual current operated circuit breaker

Abstract

The utility model discloses a tripping control circuit and a residual current operated circuit breaker, and belongs to the technical field of leakage protection. In the residual current operated circuit breaker applying the tripping control circuit, the electromagnetic tripper releases the action part when the tripping coil is powered off so as to drive the tripping mechanism to execute the tripping action. The tripping control circuit comprises an electric leakage detection module, a control module, a power supply module, a voltage reduction module, a switch module and an energy storage module. The electric leakage detection module is used for detecting the electric leakage state of the protected circuit; the step-down module is connected with the power module; the switch module and the trip coil are connected in series between the output end of the step-down module and the ground; the control module is used for controlling the on-off state of the switch module according to the leakage state; the energy storage module is used for storing energy when the power supply module outputs the power supply signal and supplying power to the trip coil when the power supply module does not output the power supply signal. According to the embodiment of the utility model, the safety and reliability of the residual current operated circuit breaker can be improved.

Description

Technical Field

[0001] This utility model relates to the field of leakage current protection technology, and in particular to a tripping control circuit and a residual current operated circuit breaker. Background Technology

[0002] Currently, electronic residual current circuit breakers on the market are prone to malfunction and damage under conditions of unstable external circuit environment, reverse wiring, or incorrect use. Damaged circuit breakers cannot protect against leakage current abnormalities, posing certain safety hazards. Specifically, the leakage current tripping coils in these circuit breakers are generally energized for tripping, with poor capacity to carry continuous tripping current, making them susceptible to damage from incorrect wiring (e.g., reverse wiring) or prolonged pressing of the test button. Furthermore, when leakage protection products themselves malfunction, they often fail to operate; for example, internal circuit damage may prevent the coil from being energized and tripping, without any external abnormalities, making the malfunction difficult to detect. Even under malfunction conditions, the circuit breaker can still close normally, posing a usage risk and potential hazard. Utility Model Content

[0003] This invention provides a tripping control circuit and a residual current operated circuit breaker to improve the safety and reliability of the residual current operated circuit breaker.

[0004] In a first aspect, this utility model provides a tripping control circuit applied to a residual current operated circuit breaker; the residual current operated circuit breaker includes: a switch, an electromagnetic trip unit, and a tripping mechanism; the switch is disposed in the protected circuit; the electromagnetic trip unit includes a trip coil and an actuating component, the electromagnetic trip unit being used to release the actuating component when the trip coil is de-energized, so as to drive the tripping mechanism to perform a tripping action, thereby opening the switch;

[0005] The tripping control circuit includes: a leakage current detection module, a control module, a power supply module, a step-down module, a switching module, and an energy storage module;

[0006] The leakage current detection module is used to detect the leakage current status of the protected circuit;

[0007] The input terminal of the step-down module is connected to the output terminal of the power supply module;

[0008] The switching module and the trip coil are connected in series between the output terminal of the step-down module and ground; the control module is connected to the control terminals of the leakage current detection module and the switching module respectively, and the control module is used to control the on / off state of the switching module according to the leakage current state;

[0009] The energy storage module is connected to the output terminal of the power module and both ends of the trip coil, respectively. The energy storage module is used to store energy when the power module outputs a power signal and to supply power to the trip coil when the power module does not output the power signal.

[0010] Optionally, the control module includes:

[0011] The first step-down unit has its input terminal connected to the output terminal of the power module;

[0012] A leakage current protection unit is provided, wherein the input terminal of the leakage current protection unit is connected to the leakage current detection module, and the power supply terminal of the leakage current protection unit is connected to the output terminal of the first step-down unit; the leakage current protection unit is used to control the potential output by the output terminal of the leakage current protection unit according to the leakage current state.

[0013] A potential control unit is provided, wherein the control terminal of the potential control unit is connected to the output terminal of the leakage current protection unit, the first input terminal of the potential control unit is connected to the output terminal of the power supply module, the second input terminal of the potential control unit is grounded, and the output terminal of the potential control unit is connected to the control terminal of the switch module; the potential control unit is used to control the output of the potential connected to the first or second input terminal of the potential control unit according to the potential of its control terminal.

[0014] Optionally, the first step-down unit includes: a first capacitor and two resistor branches; the first capacitor is connected between the output terminal of the first step-down unit and ground, and the two resistor branches are connected in parallel between the input terminal and the output terminal of the first step-down unit; the resistor branches include multiple resistors connected in series between the input terminal and the output terminal of the first step-down unit.

[0015] The leakage current protection unit includes: a leakage current protection chip, wherein the input pin of the leakage current protection chip is connected to the input terminal of the leakage current protection unit, the power supply pin of the leakage current protection chip is connected to the power supply terminal of the leakage current protection unit, the output pin of the leakage current protection chip is connected to the output terminal of the leakage current protection unit, and the grounding pin of the leakage current protection chip is grounded;

[0016] The potential control unit includes: a first transistor, a first resistor, and a second capacitor; the control electrode of the first transistor is connected to the control terminal of the potential control unit, the first electrode of the first transistor is connected to the second input terminal of the potential control unit, the second electrode of the first transistor is connected to the second terminal of the first resistor, the first terminal of the second capacitor, and the output terminal of the potential control unit, the first terminal of the first resistor is connected to the first input terminal of the potential control unit, and the second terminal of the second capacitor is grounded.

[0017] Optionally, the first end of the trip coil is connected to the output end of the step-down module, the second end of the trip coil is connected to the first end of the switching module, and the second end of the switching module is grounded;

[0018] The energy storage module includes:

[0019] The second step-down unit has its input terminal connected to the output terminal of the power module;

[0020] An energy storage unit, wherein the first end of the energy storage unit is connected to the output end of the second step-down unit and the first end of the trip coil, and the second end of the energy storage unit is grounded;

[0021] A switching unit, wherein the control terminal of the switching unit is connected to the output terminal of the second step-down unit, the input terminal of the switching unit is grounded, and the output terminal of the switching unit is connected to the second terminal of the trip coil.

[0022] Optionally, the second step-down unit includes: a second resistor connected between the input terminal and the output terminal of the second step-down unit;

[0023] The energy storage unit includes: a third capacitor, the first end of which is connected to the first end of the energy storage unit, and the second end of which is connected to the second end of the energy storage unit;

[0024] The switching unit includes: an optical coupler, wherein a first end of the emitting part of the optical coupler is connected to the control terminal of the switching unit, a second end of the emitting part is grounded, a first end of the receiving part of the optical coupler is connected to the input terminal of the switching unit, and a second end of the receiving part is connected to the output terminal of the switching unit; the optical coupler is configured to turn off the receiving part when the emitting part emits light, and to turn on the receiving part when the emitting part does not emit light.

[0025] Optionally, the energy storage unit further includes: a first diode, a second diode, and a third resistor; the first diode is connected between the output terminal of the second step-down unit and the first terminal of the third capacitor; the second diode and the third resistor are connected in series between the first terminal of the third capacitor and the first terminal of the trip coil;

[0026] The switching unit further includes a fourth capacitor and a first Zener diode, both connected between the control terminal of the switching unit and ground.

[0027] Optionally, the step-down module includes a fourth resistor and a fifth capacitor; the first end of the fourth resistor is connected to the output terminal of the power supply module, the second end of the fourth resistor is connected to the output terminal of the step-down module and the first end of the fifth capacitor, and the second end of the fifth capacitor is grounded.

[0028] Optionally, the step-down module further includes: a third diode and a second Zener diode; the third diode is connected between the second end of the fourth resistor and the output terminal of the step-down module; the second Zener diode is connected between the output terminal of the step-down module and ground.

[0029] Optionally, the power module includes: a rectifier bridge, the input terminal of which is connected to an AC power source, and the output terminal of which serves as the output terminal of the power module;

[0030] And / or,

[0031] The switching module includes a silicon controlled rectifier (SCR); the SCR and the trip coil are connected in series between the output terminal of the step-down module and ground, and the control electrode of the SCR serves as the control terminal of the switching module.

[0032] And / or,

[0033] The trip control circuit also includes:

[0034] The fifth resistor has its first end connected to the output terminal of the step-down module, and the trip coil and the switching module are connected in series between the second end of the fifth resistor and ground.

[0035] A fourth diode is connected between the two ends of the trip coil.

[0036] Secondly, this utility model embodiment also provides a residual current operated circuit breaker, including: a switch, a tripping mechanism, an electromagnetic tripping device, and a tripping control circuit provided in any embodiment of this utility model.

[0037] The tripping control circuit provided in this embodiment of the utility model includes an electromagnetic trip unit for power-off controlled tripping and provides related control circuitry, which can effectively improve circuit resistance and enhance the safety and reliability of the residual current operated circuit breaker. Specifically, as follows:

[0038] 1. Higher resistance to external circuits: Conventional energized tripping in related technologies requires applying a 230V impulse voltage to the trip coil. Therefore, the trip unit cannot cope with continuous energizing for 1 to 10 seconds, but can only cope with instantaneous energizing for less than 0.1 seconds. Under abnormal conditions, the trip coil may be damaged. In this embodiment, the electromagnetic trip unit is designed for power-off tripping. The trip coil is constantly energized when the protected circuit is normal. The voltage output from the power module is stepped down by a step-down module before being supplied to the trip coil, so that the trip coil always operates in a low-voltage state. It can withstand electrical signals for a long time without damage. Moreover, all components in the trip control circuit are designed based on the requirement of continuous energizing and have their own electrical signal carrying capacity. Even if leakage current triggers the tripping to disconnect the circuit, there will still be abnormal impulses. In principle, the risk of component burnout in the circuit is also lower.

[0039] 2. In related technologies, products with energized trip designs often show no external abnormalities when there is internal damage, such as a short circuit in the trip unit. The product can still close normally, posing a usage risk. The trip control circuit provided in this embodiment will trip the circuit breaker in all such situations, disconnecting the protected line and preventing the circuit breaker from closing, thus avoiding potential usage risks. For example, when an internal short circuit causes the trip coil power supply circuit to burn out or the trip coil itself to burn out, or when the current supplied to the circuit is too small, resulting in insufficient electromagnetic force from the electromagnetic coil, the push rod of the electromagnetic trip unit will be pushed out, causing the circuit breaker to be in a tripped / slipped state and unable to close, thereby improving the safety and reliability of the residual current operated circuit breaker.

[0040] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in 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.

[0042] Figure 1 This is a schematic diagram of the structure of a residual current operated circuit breaker provided in an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the structure of a residual current operated circuit breaker in the closed state according to an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the structure of a residual current operated circuit breaker during tripping, provided by an embodiment of this utility model;

[0045] Figure 4 This is a schematic diagram of the structure of a tripping control circuit provided in an embodiment of the present utility model;

[0046] Figure 5 This is a schematic diagram of another tripping control circuit provided in an embodiment of the present invention;

[0047] Figure 6 This is a schematic diagram of the structure of a power module and a control module provided in an embodiment of the present invention;

[0048] Figure 7 This is a schematic diagram of the structure of a step-down module, a switching module, and an energy storage module provided in an embodiment of this utility model;

[0049] Figure 8 This is an electrical signal path diagram in the tripping control circuit under normal closing state provided by an embodiment of the present invention;

[0050] Figure 9 This is an electrical signal path diagram in the trip control circuit when triggering tripping, provided by an embodiment of this utility model;

[0051] Figure 10 This is an electrical signal path diagram in a tripping control circuit during a power outage, provided by an embodiment of the present invention. Detailed Implementation

[0052] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0053] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0054] This utility model provides a tripping control circuit for residual current operated circuit breakers, used to improve the safety and reliability of residual current operated circuit breakers. For ease of explanation, the basic structure and operation process of residual current operated circuit breakers are briefly described below.

[0055] Figure 1 This is a structural schematic diagram of a residual current operated circuit breaker provided in an embodiment of this utility model. See also... Figure 1 A residual current operated circuit breaker may include: a switch (not shown in the figure), an electromagnetic trip unit 20, and a tripping mechanism. The switch is installed in the protected circuit, for example, connected in series with the protected circuit, and its opening and closing controls the connection and disconnection of the electrical circuit of the protected circuit. The electromagnetic trip unit 20 may include a trip coil and an actuating component. The electromagnetic trip unit 20 is used to release the actuating component when the trip coil is de-energized, thereby actuating the tripping mechanism to perform a tripping action, causing the switch to open and achieving protection of the protected circuit. It should be noted that, for simplicity, the residual current operated circuit breaker will be referred to as a circuit breaker in some parts of the following explanation.

[0056] Specifically, the actuating components of the electromagnetic trip unit 20 may include a spring (not shown in the figure) and a push rod 21. The tripping mechanism can be a linkage mechanism consisting of a handle 11, a connecting rod 12, a latch 13, a locking plate 14, and a lever 15. A movable S-shaped hook rod 16 is provided between the push rod 21 and the locking plate 14. The electromagnetic trip unit 20 is configured as a normally energized electromagnetic attraction trip unit, triggering power-off tripping protection when the protected line leaks current. The working principle of this residual current operated circuit breaker is as follows:

[0057] When the protected line is operating normally, the residual current operated circuit breaker closes normally. The internal state of the circuit breaker at this time can be found in [reference needed]. Figure 2 When the trip coil of the electromagnetic trip unit 20 is energized, the electromagnetic force generated causes the electromagnet to be attracted and overcome the spring force, so that the push rod 21 is in the retracted position. At this time, the latch 13 and the slot on the locking plate 14 are aligned, the tripping mechanism is in the locked state, and the lever can make the action mechanism at the switch (not shown in the figure) control the switch to the closed state. The end of the locking plate 14 can press the push rod 21 through the lower end of the S-shaped hook rod 16 so that the action component can be reliably kept in the attracted state, and the handle 11 is in the closed position.

[0058] At the moment of leakage current tripping, please refer to Figure 3 When the trip coil of the electromagnetic trip unit 20 is de-energized, the electromagnetic force disappears. The spring pushes the push rod 21 out of the housing of the electromagnetic trip unit 20, which in turn pushes the locking piece 14 through the S-shaped hook rod 16, thus unlocking the latch 13 from the locking piece 14. In other words, the tripping mechanism is unlocked. Therefore, the lever 15 moves along... Figure 3The hollow arrow indicates the direction of movement, which actuates the operating mechanism at the switch to open the switch, thus tripping the circuit breaker and de-energizing the protected line. Upon completion of the tripping operation, handle 11 can return to its original position. Figure 1 The indicated trip position.

[0059] In summary, this embodiment of the invention sets the electromagnetic trip unit 20 to be normally energized and engaged when the circuit is in normal operation, and to trigger a power-off trip when there is a leakage current. To achieve this control function, this embodiment of the invention provides a trip control circuit to detect leakage current in the protected circuit and control whether the trip coil is energized accordingly. At least some components in this trip control circuit can be integrated into the circuit board 30. The structure of this trip control circuit will be described in detail below.

[0060] Figure 4 This is a schematic diagram of a tripping control circuit provided in an embodiment of this utility model. See also... Figure 4 The tripping control circuit includes: a leakage current detection module 410, a control module 430, a power supply module 420, a step-down module 440, a switch module 450, and an energy storage module 460.

[0061] The leakage current detection module 410 is used to detect the leakage current status of the protected circuit. The input terminal of the step-down module 440 is connected to the output terminal of the power supply module 420. The switch module 450 and the trip coil KA are connected in series between the output terminal of the step-down module 440 and ground. The control module 430 is connected to the control terminals of the leakage current detection module 410 and the switch module 450 respectively, and the control module 430 is used to control the on / off state of the switch module 450 according to the leakage current status. The energy storage module 460 is connected to the output terminal of the power supply module 420 and both ends of the trip coil KA respectively; the energy storage module 460 is used to store energy when the power supply module 420 outputs a power signal, and to supply power to the trip coil KA when the power supply module 420 does not output a power signal.

[0062] Specifically, the leakage current detection module 410 can be used to detect whether there is residual current (i.e., leakage current) between the live wire and neutral wire of the protected circuit. Specifically, the leakage current detection module 410 may include a zero-sequence current transformer, through which both the neutral and live wires can pass. The induced voltage signal output from the secondary winding of the zero-sequence current transformer can be used to characterize the leakage current state of the protected circuit. For example, when the induced voltage signal is greater than a preset threshold voltage, it can be considered that leakage current has occurred in the protected circuit, and the trip coil KA needs to be de-energized to achieve tripping.

[0063] The power module 420 serves as the power source for the various electrical components of the trip control circuit. It can draw power from the protected circuit and convert it into the voltage required by the trip control circuit, or it can be an independently set power supply device. The specific structure is not limited here.

[0064] The step-down module 440 is used to step down the voltage output from the power module 420 before supplying it to the trip coil KA, so that the voltage and current carried by the trip coil KA when energized are both within the allowable range. The allowable range of voltage and current can be set according to actual needs. For example, the voltage can be reduced to below 5V, and the rated current carried by the trip coil KA can be, for example, only 1mA. For example, the step-down module 440 can be constructed as a step-down structure using a step-down chip or separate components.

[0065] The control module 430 receives the output signal from the leakage current detection module 410 and thereby determines the current leakage current status of the protected circuit. When no leakage current occurs in the protected circuit, the control module 430 can control the switch module 450 to conduct, thereby connecting the step-down module 440 to ground. This energizes the trip coil KA, providing electromagnetic force to hold the push rod 21 in the closed position, ensuring the circuit breaker closes normally. The handle 11 can also control the circuit breaker's opening and closing states. When a leakage current occurs in the protected circuit, the control module 430 can control the switch module 450 to close, de-energizing the trip coil KA to trip the circuit breaker. For example, the control module 430 may include leakage current protection-related chips and their peripheral circuits.

[0066] The switching module 450 may include controllable switching devices such as transistors.

[0067] The energy storage module 460 stores energy when the power module 420 outputs a power signal, i.e., when the power module 420 is supplying power normally, and supplies power to the trip coil KA when the power module 420 does not output a power signal, i.e., when the power module 420 fails and loses power. Thus, when the protected line does not experience leakage abnormalities but the power module 420 loses power, the energy storage module 460 can act as a temporary power source to maintain power supply to the trip coil KA, avoiding the problem of the circuit breaker tripping immediately upon power failure of the power module 420, reducing unnecessary circuit breaker operation, and improving line reliability and circuit breaker lifespan. For example, the energy storage module may include energy storage devices such as capacitors, and switching devices for controlling whether the energy storage devices are connected to the trip coil KA.

[0068] In the tripping control circuit provided in this embodiment of the utility model, an electromagnetic trip unit 20 is set for power-off controlled tripping and a related control circuit is provided, which can effectively improve circuit resistance and enhance the safety and reliability of the residual current operated circuit breaker. Specifically, as follows:

[0069] 1. Higher resistance to external circuits: Conventional energized tripping in related technologies requires applying a 230V impulse voltage to the trip coil. Therefore, the trip unit cannot cope with continuous energization for 1 to 10 seconds, but can only cope with instantaneous energization of <0.1 seconds. Under abnormal conditions, the trip coil may be damaged. In this embodiment, the electromagnetic trip unit 20 is designed for power-off tripping. The trip coil KA is constantly energized when the protected circuit is normal. The voltage output from the power module 420 is stepped down by the step-down module 440 and then supplied to the trip coil KA, so that the trip coil KA always operates in a low-voltage state, which can carry electrical signals for a long time without damage. Moreover, all components in the trip control circuit are designed based on the requirement of continuous energization and have their own electrical signal carrying capacity. Even if leakage current triggers the tripping to disconnect the circuit, there will still be abnormal impulses. In principle, the risk of component burnout in the circuit is also lower.

[0070] 2. In related technologies, products with energized trip designs often show no external abnormalities when there is internal damage, such as a short circuit in the trip unit, and the product can still close normally, posing a usage risk. The trip control circuit provided in this embodiment will trip the circuit breaker in the above situations, disconnecting the protected line and preventing the circuit breaker from closing, thus avoiding potential usage risks. For example, when an internal short circuit causes the power supply circuit of the trip coil KA to burn out or the trip coil KA itself to burn out, or when the current supplied inside the circuit is too small, resulting in insufficient electromagnetic force provided by the electromagnetic coil KA, the push rod 21 of the electromagnetic trip unit 20 will be pushed out, causing the circuit breaker to be in a tripped / slipped state and unable to close, thereby improving the safety and reliability of the residual current operated circuit breaker.

[0071] The following describes the specific structures that each module in the trip control circuit may have, but this is not intended to limit the scope of this utility model.

[0072] Figure 5 This is a schematic diagram of another tripping control circuit provided in an embodiment of this utility model. See also... Figure 5 In one embodiment, optionally, the power module 420 includes a rectifier bridge 421, the input terminal of which is connected to an AC power source, and the output terminal of the rectifier bridge 421 serving as the output terminal of the power module 420. For example, the AC power source may be provided by the protected circuit, and the input terminals of the rectifier bridge 421 may include a first input terminal L and a second input terminal N, respectively connected to the live wire and neutral wire in the protected circuit. The rectifier bridge 421 can convert the AC voltage provided by the AC power source into a DC power signal output.

[0073] For details, see Figure 6The rectifier bridge 421 can be a rectifier structure composed of four diodes. Furthermore, the power module 420 may also include a test terminal T, connected to the second input terminal N via a test resistor; the power module 420 may also include protective devices such as varistors and fuses.

[0074] See also Figure 5 Based on the above embodiments, optionally, the control module 430 includes: a first step-down unit 431, a leakage protection unit 432, and a potential control unit 433. The input terminal of the first step-down unit 431 is connected to the output terminal of the power module 420; the first step-down unit 431 is used to step down the voltage output by the power module 420 to provide power supply voltage for other functional units in the control module 430. The input terminal of the leakage protection unit 432 is connected to the leakage detection module 410, and the power supply terminal of the leakage protection unit 432 is connected to the output terminal of the first step-down unit 431; the leakage protection unit 432, as the core control component in the control module 430, is used to control the potential output by the output terminal of the leakage protection unit 432 according to the leakage state detected by the leakage detection module 410, thereby controlling the working state of the potential control unit 433. For example, the input terminals of the leakage current protection unit 432 include a third input terminal ZCT1 and a fourth input terminal ZCT2, which are respectively connected to the two ends of the secondary winding of the zero-sequence current transformer to receive the induced voltage signal output by the zero-sequence current transformer. The control terminal of the potential control unit 433 is connected to the output terminal of the leakage current protection unit 432, the first input terminal of the potential control unit 433 is connected to the output terminal of the power supply module 420, the second input terminal of the potential control unit 433 is grounded, and the output terminal of the potential control unit 433 is connected to the control terminal of the switch module 450. The potential control unit 433 is used to control the potential connected to the first or second input terminal of the output potential control unit 433 according to the potential of its control terminal, thereby controlling the on / off state of the switch module 450.

[0075] For details, see Figure 6 The first step-down unit 431 may include a first capacitor C1 and two resistor branches 4311. The first capacitor C1 is connected between the output terminal of the first step-down unit 431 and ground, and the two resistor branches 4311 are connected in parallel between the input terminal and the output terminal of the first step-down unit 431. The two resistor branches 4311 may have the same circuit structure; for example, the resistor branches 4311 may include multiple resistors connected in series between the input terminal and the output terminal of the first step-down unit 431, and the resistor branches 4311 may be a surface-mount resistor module composed of multiple surface-mount resistors. It is understood that the output terminal of the power module 420 can transmit a power signal through the power line L1.

[0076] The leakage current protection unit 432 may include: a leakage current protection chip U1, the input pin of the leakage current protection chip U1 is connected to the input terminal of the leakage current protection unit 430, the power supply pin VDD of the leakage current protection chip U1 is connected to the power supply terminal of the leakage current protection unit 432, the output pin OS of the leakage current protection chip U1 is connected to the output terminal of the leakage current protection unit 432, and the grounding pin VSS of the leakage current protection chip U1 is grounded.

[0077] Specifically, the input pins of the leakage current protection chip U1 may include a first input pin IN1 and a second input pin IN2, which are used to connect to the third input terminal ZCT1 and the fourth input terminal ZCT2, respectively. Additionally, the leakage current protection chip U1 may also include: an empty pin NC, directly grounded; a delay pin DLY, which can be grounded through a capacitor; and an activation pin OA, which can be grounded through a capacitor. Furthermore, to ensure the safe and reliable operation of the leakage current protection chip U1, the leakage current protection unit 432 may also include an external circuit composed of resistors, capacitors, and diodes to implement filtering and current limiting protection functions. For details, please refer to [link to relevant documentation]. Figure 6 This will not be elaborated upon here.

[0078] The potential control unit 433 may include: a first transistor Q1, a first resistor R1, and a second capacitor C2; the control terminal of the first transistor Q1 is connected to the control terminal of the potential control unit 433, the first terminal of the first transistor Q1 is connected to the second input terminal of the potential control unit 433, the second terminal of the first transistor Q1 is connected to the second terminal of the first resistor R1, the first terminal of the second capacitor C2, and the output terminal of the potential control unit 433, the first terminal of the first resistor R1 is connected to the first input terminal of the potential control unit 433, and the second terminal of the second capacitor C2 is grounded.

[0079] In this embodiment, the first transistor Q1 serves as a switching component in the potential control unit 433, and the first resistor R1 acts as a pull-up resistor, working in conjunction with the second capacitor C2 to achieve a voltage reduction function. Specifically, when the first transistor Q1 is controlled to conduct, it provides a low potential of the ground signal to the output terminal of the potential control unit 433; when the first transistor Q1 is controlled to turn off, the power signal, after passing through the first resistor R1, is provided as a high potential to the output terminal of the potential control unit 433. Therefore, the leakage protection unit 432 can control the potential output of the control module 430 by controlling the on / off state of the first transistor Q1. For example, the first transistor Q1 can be a transistor, such as an NPN transistor. Furthermore, the control electrode of the first transistor Q1 can also be connected to an external circuit composed of resistors and capacitors to provide functions such as current limiting. Furthermore, the potential control unit 433 may also include: a fifth diode D5, connected between the second terminal of the first transistor Q1 and the output terminal N1 of the control module 430, to realize the reverse connection protection function; for example, the anode of the fifth diode D5 is connected to the second terminal of the first transistor Q1, and the cathode is connected to the output terminal N1 of the control module 430.

[0080] Figure 7 This is a structural schematic diagram of a step-down module, a switching module, and an energy storage module provided in an embodiment of this utility model. See also... Figure 7 Based on the above embodiments, optionally, the switching module 450 includes a silicon controlled rectifier (SCR); the SCR and the trip coil KA are connected in series between the output terminal of the step-down module 440 and ground, and the control terminal of the SCR serves as the control terminal of the switching module 450. In this embodiment, the switching module 450 is composed of a SCR, resulting in a simple circuit structure that is easy to implement. For example, the trip coil KA and the SCR can be connected in series between the output terminal of the step-down module 440 and ground.

[0081] See also Figure 7 Based on the above embodiments, optionally, the step-down module 440 includes: a fourth resistor R4 and a fifth capacitor C5; the first end of the fourth resistor R4 is connected to the output terminal of the power module 420, for example, it can be connected to the power line L1; the second end of the fourth resistor R4 is connected to both the output terminal of the step-down module 440 and the first end of the fifth capacitor C5; the second end of the fifth capacitor C5 is grounded. Thus, the step-down module 440 can be constructed using a resistor-capacitor step-down structure.

[0082] Furthermore, the step-down module 440 may also include: a third diode D3 and a second Zener diode ZD2; the third diode D3 is connected between the second terminal of the fourth resistor R4 and the output terminal of the step-down module 440, for example, the anode is connected to the second terminal of the fourth resistor R4 and the cathode is connected to the output terminal of the step-down module 440 to achieve reverse connection protection. The second Zener diode ZD2 is connected between the output terminal of the step-down module 440 and ground, for example, the cathode is connected to the output terminal of the step-down module 440 and the anode is grounded to stabilize the output voltage of the step-down module 440 and provide stable power supply to the trip coil KA during normal operation. For example, the Zener voltage of the second Zener diode ZD2 can be 4.7V.

[0083] Furthermore, the trip control circuit may also include a fifth resistor R5, the first end of which is connected to the output terminal of the step-down module 440, and the trip coil KA and the switching module 450 are connected in series between the second end of the fifth resistor R5 and ground; the fifth resistor can provide current limiting. For example, the trip control circuit may also include a fourth diode D4; the fourth diode D4 is connected between the two ends of the trip coil KA, for example, the anode is connected to the end of the trip coil KA used for grounding, and the cathode is connected to the end of the trip coil KA used for connecting to the step-down module 440; the fourth diode D4 can form a freewheeling path when the trip coil KA is de-energized, releasing the residual energy on the trip coil KA.

[0084] See also Figure 5 Based on the above embodiments, optionally, the first end of the trip coil KA is connected to the output terminal of the step-down module 440, the second end of the trip coil KA is connected to the first terminal of the switch module 450, and the second terminal of the switch module 450 is grounded. The energy storage module 460 may include: a second step-down unit 461, an energy storage unit 462, and a switch unit 463.

[0085] The second step-down unit 461 has its input terminal connected to the output terminal of the power module 420. The second step-down unit 461 reduces the voltage output by the power module 420 to control the voltage of the energy storage unit 462 and meet the allowable voltage range requirements of the control terminal of the switching unit 463. The first terminal of the energy storage unit 462 is connected to both the output terminal of the second step-down unit 461 and the first terminal of the trip coil KA, while the second terminal of the energy storage unit 462 is grounded. The control terminal of the switching unit 463 is connected to the output terminal of the second step-down unit 461. The input terminal of the switching unit 463 is grounded, and the output terminal of the switching unit 463 is connected to the second terminal of the trip coil KA. By controlling whether the second terminal of the trip coil KA is grounded, the switching unit 463 can control whether the energy storage unit 462 can supply power to the trip coil KA.

[0086] For details, see Figure 7The second step-down unit 461 may include a second resistor R2, which is connected between the input and output terminals of the second step-down unit 461.

[0087] The energy storage unit 462 may include a third capacitor C3, the first end of the third capacitor C3 being connected to the first end of the energy storage unit 462, and the second end of the third capacitor C3 being connected to the second end of the energy storage unit 462; the third capacitor C3 can be used as an energy storage capacitor.

[0088] Furthermore, the energy storage unit 462 may also include: a first diode D1, a second diode D2, and a third resistor R3; the first diode D1 is connected between the output terminal of the second step-down unit 461 and the first terminal of the third capacitor C3, for example, the anode is connected to the output terminal of the second step-down unit 461, and the cathode is connected to the first terminal of the third capacitor C3, to achieve reverse connection protection. The second diode D2 and the third resistor R3 are connected in series between the first terminal of the third capacitor C3 and the first terminal of the trip coil KA, for example, the anode of the second diode D2 is connected to the first terminal of the third capacitor C3, the cathode is connected to the first terminal of the third resistor R3, and the second terminal of the third resistor R3 is connected to the first terminal of the trip coil KA; the second diode D2 provides reverse connection protection, and the third resistor R3 provides current limiting.

[0089] The switching unit 463 may include controllable switching devices such as relays. Specifically, the switching unit 463 may include an optocoupler U2. The first end of the emitting part of the optocoupler U2 is connected to the control terminal of the switching unit 463, and the second end of the emitting part is grounded. The first end of the receiving part of the optocoupler U2 is connected to the input terminal of the switching unit 463, and the second end of the receiving part is connected to the output terminal of the switching unit 463. The optocoupler U2 can be configured to turn off the receiving part when the emitting part emits light, and to turn on the receiving part when the emitting part does not emit light. That is, when a power signal is transmitted on the power line L1, the first end of the emitting part receives a high potential, causing the emitting part to emit light. At this time, the receiving part is turned off, so that no power supply circuit is formed between the energy storage unit 462 and the trip coil KA. When no power signal is transmitted on the power line L1, the first end of the emitting part has no high potential, so the emitting part does not emit light. At this time, the receiving part is turned on, so that the energy storage unit 462 can supply power to the trip coil KA.

[0090] Furthermore, the switching unit 463 also includes a fourth capacitor C4 and a first Zener diode ZD1, both connected between the control terminal of the switching unit 463 and ground. The fourth capacitor C4 provides a filtering function. The first Zener diode ZD1, for example, has its cathode connected to the control terminal of the switching unit 463 and its anode grounded, to stabilize the output voltage of the second buck unit 461 and provide a stable power supply to the optocoupler U2 during normal operation. For example, the Zener diode ZD1 can have a Zener voltage of 4.7V.

[0091] The specific structure of the tripping control circuit has been described in the above embodiments. The following will refer to... Figure 8-10 The working process of the trip control circuit will be explained. It should be noted that... Figure 8-10 The circuits in are all Figure 6 and Figure 7 The combination of the circuits shown Figure 8-10 The red line indicates the currently active / conducting circuit / device, and Figure 8-10 Only the key components are labeled.

[0092] For details, see Figure 8 When the circuit breaker is in the normal closed state, the trip coil KA and its left-side circuit are conductive along the red path. At this time, the input terminal of the leakage protection chip U1 receives a signal indicating that no leakage has occurred. Therefore, it controls the first transistor Q1 to turn off, making the control electrode of the thyristor SCR high. The thyristor SCR conducts, energizing the trip coil KA, and the electromagnetic trip unit can close the circuit normally. Simultaneously, the power signal can charge the third capacitor C3 to store energy; and the emitter of the optocoupler U2 emits light, while the receiver turns off, so that the third capacitor C3 does not supply power to the trip coil KA.

[0093] See Figure 9 When the leakage current trip is triggered, the input terminal of the leakage protection chip U1 receives a signal indicating that leakage has occurred, for example, indicating that the leakage current has reached a set threshold. The leakage protection chip U1 integrated circuit processes the output voltage to turn on the first transistor Q1, which pulls down the control electrode potential of the SCR, causing the SCR to turn off. At the same time, the third capacitor C3 in the energy storage module remains charged and the emitter of the optocoupler U2 is still emitting light, so it cannot supply power to the trip coil KA. Therefore, in this case, the trip coil KA is de-energized, causing the circuit breaker to trip and open.

[0094] See Figure 10 When the power module loses power and does not output a power signal, the transmitter of optocoupler U2 does not emit light, causing the receiver to conduct. This connects the power supply circuit of the third capacitor C3 to the trip coil KA, supplying power to the trip coil KA. For example, because the power consumption of the electromagnetic trip unit is very low, the third capacitor C3 can maintain continuous power supply for more than 40 hours from a fully charged state, preventing the problem of tripping immediately upon power failure.

[0095] In summary, the trip control circuit provided in this embodiment of the present invention, under normal operating conditions, can control whether the trip coil KA is energized based on the leakage current detected by the magnetic ring, while simultaneously charging the energy storage module. This circuit provides a power-off trip function; during tripping, the push rod of the electromagnetic trip unit pushes open the trip mechanism latch to unlock, allowing the electromagnetic trip unit to actuate and drive the circuit breaker switch to disconnect the electrical circuit of the protected line. When the power module output voltage is too low or there is no output voltage: the optocoupler loses voltage, thereby connecting the power supply circuit of the third capacitor to the trip coil, continuously maintaining the pull-in current for the electromagnetic trip unit, and avoiding accidental tripping due to short-term power outages.

[0096] This utility model embodiment also provides a residual current operated circuit breaker, including the tripping control circuit provided in any embodiment of this utility model, which has corresponding beneficial effects. Specifically, the residual current operated circuit breaker may include: a switch, a tripping mechanism, an electromagnetic trip unit, and a tripping control circuit. At least some modules of the tripping control circuit can be integrated onto a circuit board for placement within the casing of the residual current operated circuit breaker. For example, the detection component of the leakage current detection module can be located at the protected circuit to detect whether leakage current exists in the protected circuit. All components in the tripping control circuit except for the detection component of the leakage current detection module can be integrated onto the circuit board. The novel high-safety residual current operated circuit breaker provided by this utility model embodiment can detect leakage current in the circuit and quickly cut off the power supply when the leakage current exceeds a preset value, thereby ensuring personal safety and equipment integrity.

[0097] It should be understood that the various forms of the process shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this utility model can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this utility model can be achieved, and this is not limited herein.

[0098] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A tripping control circuit, characterized in that, Applied to residual current operated circuit breakers; The residual current operated circuit breaker includes: a switch, an electromagnetic trip unit, and a tripping mechanism; the switch is installed in the protected circuit; the electromagnetic trip unit includes a trip coil and an actuating component, and the electromagnetic trip unit is used to release the actuating component when the trip coil is de-energized, so as to drive the tripping mechanism to perform a tripping action and open the switch; The tripping control circuit includes: a leakage current detection module, a control module, a power supply module, a step-down module, a switching module, and an energy storage module; The leakage current detection module is used to detect the leakage current status of the protected circuit; The input terminal of the step-down module is connected to the output terminal of the power supply module; The switching module and the trip coil are connected in series between the output terminal of the step-down module and ground; the control module is connected to the control terminals of the leakage current detection module and the switching module respectively, and the control module is used to control the on / off state of the switching module according to the leakage current state; The energy storage module is connected to the output terminal of the power module and both ends of the trip coil, respectively. The energy storage module is used to store energy when the power module outputs a power signal and to supply power to the trip coil when the power module does not output the power signal.

2. The tripping control circuit according to claim 1, characterized in that, The control module includes: The first step-down unit has its input terminal connected to the output terminal of the power module; A leakage current protection unit is provided, wherein the input terminal of the leakage current protection unit is connected to the leakage current detection module, and the power supply terminal of the leakage current protection unit is connected to the output terminal of the first step-down unit; the leakage current protection unit is used to control the potential output by the output terminal of the leakage current protection unit according to the leakage current state. A potential control unit is provided, wherein the control terminal of the potential control unit is connected to the output terminal of the leakage current protection unit, the first input terminal of the potential control unit is connected to the output terminal of the power supply module, the second input terminal of the potential control unit is grounded, and the output terminal of the potential control unit is connected to the control terminal of the switch module; the potential control unit is used to control the output of the potential connected to the first or second input terminal of the potential control unit according to the potential of its control terminal.

3. The tripping control circuit according to claim 2, characterized in that, The first step-down unit includes: a first capacitor and two resistor branches; the first capacitor is connected between the output terminal of the first step-down unit and ground, and the two resistor branches are connected in parallel between the input terminal and the output terminal of the first step-down unit; each resistor branch includes multiple resistors connected in series between the input terminal and the output terminal of the first step-down unit. The leakage current protection unit includes: a leakage current protection chip, wherein the input pin of the leakage current protection chip is connected to the input terminal of the leakage current protection unit, the power supply pin of the leakage current protection chip is connected to the power supply terminal of the leakage current protection unit, the output pin of the leakage current protection chip is connected to the output terminal of the leakage current protection unit, and the grounding pin of the leakage current protection chip is grounded; The potential control unit includes: a first transistor, a first resistor, and a second capacitor; the control electrode of the first transistor is connected to the control terminal of the potential control unit, the first electrode of the first transistor is connected to the second input terminal of the potential control unit, the second electrode of the first transistor is connected to the second terminal of the first resistor, the first terminal of the second capacitor, and the output terminal of the potential control unit, the first terminal of the first resistor is connected to the first input terminal of the potential control unit, and the second terminal of the second capacitor is grounded.

4. The tripping control circuit according to claim 1, characterized in that, The first end of the trip coil is connected to the output end of the step-down module, the second end of the trip coil is connected to the first end of the switching module, and the second end of the switching module is grounded. The energy storage module includes: The second step-down unit has its input terminal connected to the output terminal of the power module; An energy storage unit, wherein the first end of the energy storage unit is connected to the output end of the second step-down unit and the first end of the trip coil, and the second end of the energy storage unit is grounded; A switching unit, wherein the control terminal of the switching unit is connected to the output terminal of the second step-down unit, the input terminal of the switching unit is grounded, and the output terminal of the switching unit is connected to the second terminal of the trip coil.

5. The tripping control circuit according to claim 4, characterized in that, The second step-down unit includes: a second resistor connected between the input terminal and the output terminal of the second step-down unit; The energy storage unit includes: a third capacitor, the first end of which is connected to the first end of the energy storage unit, and the second end of which is connected to the second end of the energy storage unit; The switching unit includes: an optical coupler, wherein a first end of the emitting part of the optical coupler is connected to the control terminal of the switching unit, a second end of the emitting part is grounded, a first end of the receiving part of the optical coupler is connected to the input terminal of the switching unit, and a second end of the receiving part is connected to the output terminal of the switching unit; the optical coupler is configured to turn off the receiving part when the emitting part emits light, and to turn on the receiving part when the emitting part does not emit light.

6. The tripping control circuit according to claim 5, characterized in that, The energy storage unit further includes: a first diode, a second diode, and a third resistor; the first diode is connected between the output terminal of the second step-down unit and the first terminal of the third capacitor; the second diode and the third resistor are connected in series between the first terminal of the third capacitor and the first terminal of the trip coil; The switching unit further includes a fourth capacitor and a first Zener diode, both connected between the control terminal of the switching unit and ground.

7. The tripping control circuit according to claim 1, characterized in that, The step-down module includes a fourth resistor and a fifth capacitor; the first end of the fourth resistor is connected to the output end of the power supply module, the second end of the fourth resistor is connected to the output end of the step-down module and the first end of the fifth capacitor, and the second end of the fifth capacitor is grounded.

8. The tripping control circuit according to claim 7, characterized in that, The step-down module further includes: a third diode and a second Zener diode; the third diode is connected between the second end of the fourth resistor and the output end of the step-down module; the second Zener diode is connected between the output end of the step-down module and ground.

9. The tripping control circuit according to claim 1, characterized in that, The power module includes a rectifier bridge, the input terminal of which is connected to an AC power source, and the output terminal of which serves as the output terminal of the power module. And / or, The switching module includes a silicon controlled rectifier (SCR); the SCR and the trip coil are connected in series between the output terminal of the step-down module and ground, and the control electrode of the SCR serves as the control terminal of the switching module. And / or, The tripping control circuit also includes: The fifth resistor has its first end connected to the output terminal of the step-down module, and the trip coil and the switching module are connected in series between the second end of the fifth resistor and ground. A fourth diode is connected between the two ends of the trip coil.

10. A residual current operated circuit breaker, characterized in that, include: A switch, a tripping mechanism, an electromagnetic trip unit, and a tripping control circuit according to any one of claims 1-9.

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