Trip control circuit and residual current operated circuit breaker

Abstract

The invention 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 invention, the safety and reliability of the residual current operated circuit breaker can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of leakage protection, in particular to a tripping control circuit and a residual current operated circuit breaker. Background Art

[0002] Currently, the electronic residual current operated circuit breakers on the market are prone to abnormalities and damage when the external circuit environment of the load is unstable, reverse wiring or incorrect use is carried out. The damaged circuit breaker cannot protect against leakage abnormalities, which poses certain safety hazards. Specifically, the leakage action coils in the circuit breakers in the related art are generally energized and tripped, and have poor ability to carry continuous tripping current. They are easily damaged by incorrect wiring (such as reverse wiring) or long pressing of the test button and other incorrect operations; moreover, the leakage protection products in the related art usually do not operate when abnormalities occur. For example, the internal circuit of the product is damaged, so the coil cannot be energized and cannot be tripped, and there is no external abnormality, making it difficult to detect product abnormalities. The circuit breaker can still close normally under abnormal conditions, which poses usage risks and potential hidden dangers. Summary of the Invention

[0003] The present invention provides a trip 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, an embodiment of the present invention provides a trip control circuit for use in a residual current operated circuit breaker. The residual current operated circuit breaker includes a switch, an electromagnetic trip, and a trip mechanism. The switch is disposed in a protected circuit. The electromagnetic trip includes a trip coil and an actuating component. The electromagnetic trip is configured to release the actuating component when the trip coil is de-energized, thereby driving the trip mechanism to perform a tripping action and disconnect the switch.

[0005] The trip control circuit includes: a leakage detection module, a control module, a power supply module, a voltage reduction module, a switch module and an energy storage module;

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

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

[0008] 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 connected to the leakage detection module and the control end of the switch module respectively, and the control module is used to control the on-off state of the switch module according to the leakage state;

[0009] The energy storage module is respectively connected to the output end of the power module and the two ends of the trip coil; 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] a first step-down unit, wherein an input end of the first step-down unit is connected to an output end of the power module;

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

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

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

[0015] The leakage protection unit includes: a leakage protection chip, an input pin of the leakage protection chip is connected to the input end of the leakage protection unit, a power supply pin of the leakage protection chip is connected to the power supply end of the leakage protection unit, an output pin of the leakage protection chip is connected to the output end of the leakage protection unit, and a ground pin of the leakage 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 end of the potential control unit, the first electrode of the first transistor is connected to the second input end of the potential control unit, the second electrode of the first transistor is respectively connected to the second end of the first resistor, the first end of the second capacitor and the output end of the potential control unit, the first end of the first resistor is connected to the first input end of the potential control unit, and the second end 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 switch module, and the second end of the switch module is grounded;

[0018] The energy storage module includes:

[0019] a second step-down unit, wherein an input end of the second step-down unit is connected to an output end of the power module;

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

[0021] A switch unit, wherein the control end of the switch unit is connected to the output end of the second step-down unit, the input end of the switch unit is grounded, and the output end of the switch unit is connected to the second end 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, a first end of the third capacitor is connected to the first end of the energy storage unit, and a second end of the third capacitor is connected to the second end of the energy storage unit;

[0024] The switch unit includes: an optical coupler, wherein a first end of a transmitting part of the optical coupler is connected to a control end of the switch unit, a second end of the transmitting part is grounded, a first end of a receiving part of the optical coupler is connected to an input end of the switch unit, and a second end of the receiving part is connected to an output end of the switch unit; the optical coupler is configured such that the receiving part is turned off when the transmitting part emits light, and the receiving part is turned on when the transmitting 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 end of the second step-down unit and the first end of the third capacitor; the second diode and the third resistor are connected in series between the first end of the third capacitor and the first end of the trip coil;

[0026] The switch unit further includes: a fourth capacitor and a first voltage regulator tube, both connected between the control end of the switch unit and the 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 end of the power supply module, the second end of the fourth resistor is respectively 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.

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

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

[0030] and / or,

[0031] The switch module includes: a thyristor; the thyristor and the trip coil are connected in series between the output end of the step-down module and the ground, and the control electrode of the thyristor serves as the control end of the switch module;

[0032] and / or,

[0033] The trip control circuit further includes:

[0034] a fifth resistor, wherein a first end of the fifth resistor is connected to the output end of the step-down module, and the trip coil and the switch module are connected in series between a second end of the fifth resistor and ground;

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

[0036] In a second aspect, an embodiment of the present invention further provides a residual current operated circuit breaker, comprising: a switch, a tripping mechanism, an electromagnetic tripper, and a tripping control circuit provided by any embodiment of the present invention.

[0037] In the trip control circuit provided by the embodiment of the present invention, an electromagnetic trip is provided for power-off control tripping and a related control circuit is provided, which can effectively improve the circuit resistance and enhance the safety and reliability of the residual current operated circuit breaker. The details are as follows:

[0038] 1. Higher resistance to external circuits: Conventional power-on tripping in related technologies requires applying a 230V surge voltage to the trip coil. Therefore, the trip device cannot handle continuous power-on for as short as 1s or as long as 10s, and can only handle momentary power-on for less than 0.1s. Under abnormal conditions, the trip coil may be damaged. In an embodiment of the present invention, the electromagnetic trip device is designed for power-off tripping. The trip coil is always energized when the protected line is normal, and the voltage output by the power module is stepped down by the step-down module and supplied to the trip coil. This allows the trip coil to always operate at a low voltage, allowing it to carry electrical signals for a long time and avoid damage. In addition, all components in the trip control circuit are designed based on the requirement of continuous power-on and have inherent electrical signal carrying capacity. Even if there is still an abnormal shock after the leakage triggers the trip to disconnect the line, the risk of burning components in the circuit is theoretically lower.

[0039] 2. In the related art, the products with power-on tripping design usually do not show any external abnormalities when there is internal damage to the product, such as a short circuit in the tripper, and the product can still be closed normally, which poses a risk of use. The tripping control circuit provided by the embodiment of the present invention will trip the circuit breaker under the above circumstances, disconnect the protected line, and make the circuit breaker unable to close and be in a sliding state, thereby avoiding potential risks of use. For example, when a short circuit inside the circuit causes the power supply circuit of the tripping coil to burn out or the tripping coil itself to burn out, or when the current provided inside the circuit is too small so that the electromagnetic force provided by the electromagnetic coil is too small, the top rod of the electromagnetic tripper will be pushed out, causing the circuit breaker to be in a tripped / sliding 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 content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

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

[0043] Figure 2 This is a structural diagram of a residual current operated circuit breaker in a closed state provided by an embodiment of the present invention;

[0044] Figure 3This is a schematic structural diagram of a residual current operated circuit breaker provided by an embodiment of the present invention when it is tripped;

[0045] Figure 4 1 is a schematic structural diagram of a trip control circuit provided by an embodiment of the present invention;

[0046] Figure 5 1 is a schematic structural diagram of another trip control circuit provided by an embodiment of the present invention;

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

[0048] Figure 7 This is a structural diagram of a step-down module, a switch module, and an energy storage module provided by an embodiment of the present invention;

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

[0050] Figure 9 This is an electrical signal path diagram in a trip control circuit when a trip is triggered, provided by an embodiment of the present invention;

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

[0052] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0053] It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and the accompanying drawings are used to distinguish similar items and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0054] An embodiment of the present invention provides a trip control circuit for use in a residual current operated circuit breaker to improve the safety and reliability of the residual current operated circuit breaker. For ease of explanation, the basic structure and operation process of the residual current operated circuit breaker are briefly described below.

[0055] Figure 1 This is a schematic diagram of the structure of a residual current operated circuit breaker provided by an embodiment of the present invention. Figure 1 The residual current operated circuit breaker may include: a switch (not shown in the figure), an electromagnetic release 20 and a tripping mechanism. The switch is arranged in the protected line, for example, connected in series in the protected line, and the on and off of the switch can control the on and off of the electrical circuit of the protected line. The electromagnetic release 20 may include a tripping coil and an action component. The electromagnetic release 20 is used to release the action component when the tripping coil is de-energized, so as to drive the tripping mechanism to perform a tripping action, disconnect the switch, and realize protection of the protected line. It should be noted that in the following explanation, the residual current operated circuit breaker is referred to as a circuit breaker for simplicity.

[0056] Specifically, the operating components of the electromagnetic release 20 may include a spring (not shown) and a push rod 21. The tripping mechanism may be a linkage mechanism consisting of a handle 11, a connecting rod 12, a lock 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 release 20 is configured as a normally energized electromagnetic pull-in release, and triggers a power-off trip protection when the protected line leaks. The operating 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 is closed normally. The internal state of the circuit breaker at this time can be seen in Figure 2 , wherein the tripping coil of the electromagnetic release 20 is energized, and the electromagnetic force generated causes the electromagnet to be attracted to overcome the spring force, so that the push rod 21 is in the retracted position; at this time, the lock buckle 13 is aligned with the slot on the lock plate 14, and the tripping mechanism is in a locked state. The lever can enable the action mechanism at the switch (not shown in the figure) to control the switch to a closed state. The end of the lock plate 14 can press the push rod 21 through the lower end of the S-shaped hook rod 16 to ensure that the action component remains reliably in the attracted state, and the handle 11 is in the closed position.

[0058] At the moment of leakage tripping, see Figure 3 , the tripping coil of the electromagnetic release 20 loses power, so that the electromagnetic force disappears, and the spring pushes the top rod 21 out of the electromagnetic release 20 housing, and then pushes the lock plate 14 through the S-shaped hook rod 16, so that the lock 13 and the lock plate 14 are unlocked, that is, the tripping mechanism is unlocked, so the lever 15 moves along Figure 3The hollow arrow moves in the direction indicated by the handle and drives the action mechanism of the switch to open the switch, thereby tripping the circuit breaker and de-energizing the protected circuit. Figure 1 The OFF position is shown.

[0059] In summary, the electromagnetic trip device 20 of the present embodiment is configured to be constantly energized when the circuit is operating normally, and to trigger a power-off trip when a current leakage occurs. To implement this control function, the present embodiment provides a trip control circuit that detects current leakage in the protected circuit and controls whether the trip coil is energized. At least some components of this trip control circuit can be integrated into the circuit board 30. The structure of this trip control circuit is described in detail below.

[0060] Figure 4 Schematic diagram of a trip control circuit provided by an embodiment of the present invention. Figure 4 The trip control circuit includes: a leakage detection module 410, a control module 430, a power module 420, a voltage reduction module 440, a switch module 450 and an energy storage module 460.

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

[0062] The leakage detection module 410 can be used to detect whether residual current (i.e., leakage current) occurs between the live and neutral wires of the protected circuit. Specifically, the leakage detection module 410 can include a zero-sequence current transformer (CCT), through which both the live and neutral wires pass. The induced voltage signal output by the secondary winding of the CCT can be used to characterize the leakage state of the protected circuit. For example, when the induced voltage signal is greater than a preset threshold voltage, it can be considered that a leakage 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 electrical components of the trip control circuit. It can draw power from the protected line 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] Step-down module 440 is used to step down the voltage output by power module 420 and supply it to trip coil KA. This ensures that the voltage and current carried by trip coil KA when energized are within the permitted range. These permitted voltage and current ranges can be set based on actual needs. For example, the voltage can be reduced to below 5V, and the rated current carried by trip coil KA can be only 1mA. For example, step-down module 440 can be implemented using a step-down chip or discrete components to form a step-down structure.

[0065] The control module 430 receives the output signal of the leakage detection module 410 and obtains the current leakage status of the protected line based on it. When there is no leakage in the protected line, the control module 430 can control the switch module 450 to be turned on, so that the line between the step-down module 440 and the ground is turned on, and the tripping coil KA can be energized to provide electromagnetic force, keeping the top rod 21 in the attracted position, ensuring the normal closing of the circuit breaker, and can control the opening and closing status of the circuit breaker through the handle 11. When there is a leakage in the protected line, the control module 430 can control the switch module 450 to be turned off, so that the tripping coil KA loses power to achieve the tripping of the circuit breaker. Exemplarily, the control module 430 may include a chip related to leakage protection and its peripheral circuits.

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

[0067] The energy storage module 460 stores energy when the power module 420 outputs a power signal, that is, when the power module 420 is able to supply power normally, and supplies power to the trip coil KA when the power module 420 does not output a power signal, that is, when the power module 420 fails and loses power. In this way, when there is no leakage abnormality in the protected line but the power module 420 loses power, the energy storage module 460 can act as a temporary power source to maintain the power supply to the trip coil KA, avoiding the problem of the circuit breaker tripping as soon as the power module 420 loses power, reducing unnecessary actions of the circuit breaker, and helping to improve line reliability and the service life of the circuit breaker. Exemplarily, the energy storage module may include energy storage devices such as capacitors, as well as switching devices for controlling whether the energy storage device is connected to the trip coil KA.

[0068] In the trip control circuit provided by the embodiment of the present invention, an electromagnetic trip 20 is provided for power-off control tripping and a related control circuit is provided, which can effectively improve the circuit resistance and enhance the safety and reliability of the residual current operated circuit breaker. The details are as follows:

[0069] 1. Higher resistance to external circuits: Conventional power-on tripping in related technologies requires applying a 230V surge voltage to the trip coil. Therefore, the trip device cannot handle continuous power-on for periods as short as 1s or as long as 10s, and can only handle momentary power-on for less than 0.1s. Under abnormal circumstances, the trip coil may be damaged. In this embodiment of the present invention, the electromagnetic trip device 20 is designed for power-off tripping. The trip coil KA is always energized when the protected line is normal, and the voltage output by the power module 420 is stepped down by the step-down module 440 and supplied to the trip coil KA. This ensures that the trip coil KA always operates at a low voltage, allowing it to carry electrical signals for a long time without being damaged. All components in the trip control circuit are designed based on the requirement for continuous power-on and have inherent electrical signal carrying capacity. Even if leakage triggers the trip and disconnects the line, there is still an abnormal surge. In principle, the risk of burning out components in the circuit is also reduced.

[0070] 2. In the related art, when there is internal damage to the product, such as a short circuit in the tripper, the power-on tripping design product usually does not show any external abnormalities, and the product can still be closed normally, which poses a risk of use. The tripping control circuit provided by the embodiment of the present invention will trip the circuit breaker under the above circumstances, disconnect the protected line, and make the circuit breaker unable to close and slide, thereby avoiding potential risks of use. For example, when a short circuit inside the circuit causes the power supply circuit of the tripping coil KA to burn out or the tripping coil KA itself to burn out, or when the current provided inside the circuit is too small so that the electromagnetic force provided by the electromagnetic coil KA is too small, the top rod 21 of the electromagnetic tripper 20 will be pushed out, causing the circuit breaker to be in a tripped / sliding 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 does not limit the present invention.

[0072] Figure 5 Schematic diagram of another trip control circuit provided by an embodiment of the present invention. Figure 5 In one embodiment, the power module 420 optionally includes a rectifier bridge 421. The input of the rectifier bridge 421 is connected to an AC power source, and the output of the rectifier bridge 421 serves as the output of the power module 420. For example, the AC power source may be provided by a protected circuit. The input of the rectifier bridge 421 may include a first input terminal L and a second input terminal N, connected to the live wire and neutral wire of the protected circuit, respectively. The rectifier bridge 421 converts the AC voltage provided by the AC power source into a DC power signal for output.

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

[0074] Continue to see Figure 5 Based on the above embodiments, the control module 430 optionally includes: a first step-down unit 431, a leakage protection unit 432, and a potential control unit 433. The input end of the first step-down unit 431 is connected to the output end 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 a power supply voltage for other functional units in the control module 430. The input end of the leakage protection unit 432 is connected to the leakage detection module 410, and the power supply end of the leakage protection unit 432 is connected to the output end of the first step-down unit 431; the leakage protection unit 432 serves as the core control component in the control module 430 and is used to control the potential output by the output end 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. Exemplarily, the input terminals of the leakage protection unit 432 include a third input terminal ZCT1 and a fourth input terminal ZCT2, which are, for example, 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 protection unit 432, the first input terminal of the potential control unit 433 is connected to the output terminal of the power 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 configured to control the potential connected to the first input terminal or the second input terminal of the output potential control unit 433 based on 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. The resistor branches 4311 may be a chip resistor module composed of multiple chip resistors. It is understood that the output terminal of the power module 420 can transmit a power signal via the power line L1.

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

[0077] Specifically, the input pins of the leakage protection chip U1 may include a first input pin IN1 and a second input pin IN2, which are respectively used to connect to the third input terminal ZCT1 and the fourth input terminal ZCT2. In addition, the leakage protection chip U1 may also be provided with: an empty pin NC, which is 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. In addition, to ensure the safe and reliable operation of the leakage protection chip U1, the leakage protection unit 432 may also be provided with a peripheral circuit composed of resistors, capacitors, and diodes to implement protection functions such as filtering and current limiting. For details, please refer to Figure 6 , I will not go into details here.

[0078] The potential control unit 433 may include: a first transistor Q1, a first resistor R1 and a second capacitor C2; the control electrode of the first transistor Q1 is connected to the control end of the potential control unit 433, the first electrode of the first transistor Q1 is connected to the second input end of the potential control unit 433, the second electrode of the first transistor Q1 is respectively connected to the second end of the first resistor R1, the first end of the second capacitor C2 and the output end of the potential control unit 433, the first end of the first resistor R1 is connected to the first input end of the potential control unit 433, and the second end 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 can serve as a pull-up resistor, while cooperating with the second capacitor C2 to achieve a voltage reduction function. Specifically, when the first transistor Q1 is controlled to be turned on, the low potential of the ground signal can be provided to the output end of the potential control unit 433; when the first transistor Q1 is controlled to be turned off, the power signal is provided to the output end of the potential control unit 433 as a high potential after passing through the first resistor R1. Therefore, the leakage protection unit 432 can control the potential output by the control module 430 by controlling the on and off of the first transistor Q1. Exemplarily, 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 a peripheral circuit composed of a resistor and a capacitor to provide functions such as green mint current limiting. In addition, the potential control unit 433 may also include: a fifth diode D5, connected between the second pole of the first transistor Q1 and the output terminal N1 of the control module 430 to achieve an anti-reverse connection protection function; the fifth diode D5, for example, has an anode connected to the second pole of the first transistor Q1 and a cathode connected to the output terminal N1 of the control module 430.

[0080] Figure 7 This is a schematic diagram of the structure of a step-down module, a switch module and an energy storage module provided by an embodiment of the present invention. Figure 7 Based on the above embodiments, the switch module 450 optionally includes a thyristor (SCR); the SCR and the trip coil KA are connected in series between the output terminal of the step-down module 440 and ground, with the control electrode of the SCR serving as the control terminal of the switch module 450. In this embodiment, the switch module 450 is composed of thyristors (SCRs), resulting in a simple circuit structure and ease of implementation. 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] Continue to see Figure 7 Based on the above embodiments, the step-down module 440 optionally includes a fourth resistor R4 and a fifth capacitor C5. The first end of the fourth resistor R4 is connected to the output end of the power module 420, for example, the power line L1. The second end of the fourth resistor R4 is connected to the output end of the step-down module 440 and the first end of the fifth capacitor C5, respectively. The second end of the fifth capacitor C5 is grounded. In this way, 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 voltage regulator diode ZD2. The third diode D3 is connected between the second end of the fourth resistor R4 and the output of the step-down module 440, for example, with its anode connected to the second end of the fourth resistor R4 and its cathode connected to the output of the step-down module 440, to implement reverse polarity protection. The second voltage regulator diode ZD2 is connected between the output of the step-down module 440 and ground, for example, with its cathode connected to the output of the step-down module 440 and its anode connected to ground, to stabilize the output voltage of the step-down module 440 and provide stable power to the trip coil KA during normal operation. For example, the regulated voltage of the second voltage regulator diode ZD2 may be 4.7V.

[0083] Furthermore, the trip control circuit may further include: a fifth resistor R5, wherein a first end of the fifth resistor R5 is connected to the output end of the step-down module 440, and the trip coil KA and the switch module 450 are connected in series between the second end of the fifth resistor R5 and ground; the fifth resistor may provide current limiting. Exemplarily, the trip control circuit may further 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 that is grounded, and the cathode is connected to the end of the trip coil KA that is connected to the step-down module 440; the fourth diode D4 can form a freewheeling path when the trip coil KA loses power, releasing residual energy in the trip coil KA.

[0084] Continue to see Figure 5 Based on the above embodiments, optionally, the first end of the trip coil KA is connected to the output end of the step-down module 440, the second end of the trip coil KA is connected to the first end of the switch module 450, and the second end 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 input of the second step-down unit 461 is connected to the output of the power module 420. The second step-down unit 461 is used to step down the voltage output by the power module 420 to control the voltage of the energy storage unit 462 and meet the allowable range of the voltage at the control terminal of the switch unit 463. The first terminal of the energy storage unit 462 is connected to the output of the second step-down unit 461 and the first terminal of the trip coil KA, respectively. The second terminal of the energy storage unit 462 is grounded. The control terminal of the switch unit 463 is connected to the output of the second step-down unit 461, the input terminal of the switch unit 463 is grounded, and the output terminal of the switch 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 switch unit 463 controls 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 connected between the input end and the output end of the second step-down unit 461.

[0087] The energy storage unit 462 may include: a third capacitor C3, a first end of the third capacitor C3 is connected to the first end of the energy storage unit 462, and a second end of the third capacitor C3 is 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 further include: a first diode D1, a second diode D2, and a third resistor R3; the first diode D1 is connected between the output end of the second step-down unit 461 and the first end of the third capacitor C3, for example, with the anode connected to the output end of the second step-down unit 461 and the cathode connected to the first end of the third capacitor C3, to implement a reverse polarity protection function. The second diode D2 and the third resistor R3 are connected in series between the first end of the third capacitor C3 and the first end of the trip coil KA, for example, with the anode of the second diode D2 connected to the first end of the third capacitor C3, the cathode connected to the first end of the third resistor R3, and the second end of the third resistor R3 connected to the first end of the trip coil KA; the second diode D2 provides reverse polarity protection, and the third resistor R3 provides current limiting.

[0089] Switch unit 463 may include a controllable switching device, such as a relay. Specifically, switch unit 463 may include an optocoupler U2, wherein the first end of the transmitter of optocoupler U2 is connected to the control end of switch unit 463, the second end of the transmitter is grounded, the first end of the receiver of optocoupler U2 is connected to the input end of switch unit 463, and the second end of the receiver is connected to the output end of switch unit 463. Optocoupler U2 can be configured so that the receiver is off when the transmitter emits light and on when the transmitter does not emit light. That is, when a power signal is transmitted on power line L1, the first end of the transmitter receives a high voltage, causing the transmitter to emit light. At this time, the receiver is off, preventing the energy storage unit 462 from forming a power supply circuit with the trip coil KA. When the power signal is not transmitted on power line L1, the first end of the transmitter has no high voltage, causing the transmitter to not emit light. At this time, the receiver is on, allowing the energy storage unit 462 to supply power to the trip coil KA.

[0090] Furthermore, the switch unit 463 also includes a fourth capacitor C4 and a first voltage regulator diode ZD1, both connected between the control terminal of the switch unit 463 and ground. The fourth capacitor C4 can provide a filtering function. The first voltage regulator diode ZD1, for example, has its cathode connected to the control terminal of the switch unit 463 and its anode connected to ground, to stabilize the output voltage of the second step-down unit 461 and provide stable power to the optocoupler U2 during normal operation. For example, the regulated voltage of the first voltage regulator diode ZD1 can be 4.7V.

[0091] The specific structure of the trip control circuit is described in the above embodiments. Figure 8-10 , the working process of the trip control circuit is explained. It should be noted that, Figure 8-10 The circuits in Figure 6 and Figure 7 The combination of the circuits shown, Figure 8-10 The red line indicates the circuit / device that is currently conducting / acting, and Figure 8-10 Only key components are marked.

[0092] For details, see Figure 8 When the circuit breaker is in the normal closed state, the trip coil KA and the circuit to its left are conducting along the red path. At this point, the input terminal of the leakage protection chip U1 receives a signal indicating that no leakage has occurred. Therefore, the first transistor Q1 is turned off, causing the control terminal of the thyristor (SCR) to reach a high voltage. The thyristor (SCR) conducts, energizing the trip coil KA and allowing the electromagnetic trip device to close normally. Simultaneously, the power signal charges the third capacitor C3 for energy storage. Furthermore, the transmitting portion of the optocoupler U2 emits light, while the receiving portion is turned off, preventing the third capacitor C3 from supplying power to the trip coil KA.

[0093] See also Figure 9 When a leakage trip is triggered, the input terminal of the leakage protection chip U1 receives a signal indicating that the current leakage state is occurring, for example, indicating that the leakage current has reached a set threshold. The leakage protection chip U1 integrated circuit processes the output voltage, turning on the first transistor Q1, which lowers the gate potential of the thyristor (SCR), turning off the thyristor. Simultaneously, the energy storage module maintains a charged state for the third capacitor C3 and emits light from the optocoupler U2, preventing power from being supplied to the trip coil KA. Therefore, in this situation, the trip coil KA loses power, causing the circuit breaker to trip.

[0094] See also Figure 10 When the power module loses power and stops outputting a power signal, the transmitter of optocoupler U2 turns off, turning on the receiver. This connects the power supply circuit of trip coil KA to third capacitor C3, supplying power to trip coil KA. For example, because the electromagnetic tripper consumes very little power when engaged, capacitor C3 can maintain continuous power for over 40 hours from a fully charged state, preventing tripping upon power outages.

[0095] In summary, the tripping control circuit provided in the embodiment of the present invention can, when the circuit is working normally, control whether the tripping coil KA is energized according to the leakage state detected by the magnetic ring, and charge the energy storage module at the same time. Among them, the circuit can provide a power-off tripping function. When tripping, the top rod of the electromagnetic tripper pushes the tripping mechanism lock to unlock it, so that the action of the electromagnetic tripper can drive the circuit breaker switch to disconnect the electrical circuit of the protected line. In the working condition where the output voltage of the power module is too low or there is no output voltage: the optocoupler loses voltage and thus connects the power supply circuit of the tripping coil to the third capacitor, continuously maintaining the pull-in current for the electromagnetic tripper, and avoiding accidental tripping caused by short-term power outages.

[0096] The embodiment of the present invention also provides a residual current operated circuit breaker, including the tripping control circuit provided by any embodiment of the present invention, and having corresponding beneficial effects. Specifically, the residual current operated circuit breaker may include: a switch, a tripping mechanism, an electromagnetic tripper and a tripping control circuit. Among them, at least some modules in the tripping control circuit can be integrated on a circuit board so as to be placed in the housing of the residual current operated circuit breaker. For example, the detection component of the leakage detection module can be set at the protected line to detect whether there is leakage current in the protected line, and all components in the tripping control circuit except the detection component of the leakage detection module can be integrated on the circuit board. The new high-safety residual current operated circuit breaker provided by the embodiment of the present invention can detect leakage current in the circuit and quickly cut off the power supply when the leakage current exceeds the preset value, thereby ensuring personal safety and equipment integrity.

[0097] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0098] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A trip control circuit, characterized in that: Applied to residual current operated circuit breakers; The residual current operated circuit breaker includes: a switch, an electromagnetic trip and a tripping mechanism; the switch is arranged in the protected circuit; the electromagnetic trip includes a tripping coil and an action component, and the electromagnetic trip is used to release the action component when the tripping coil is de-energized, thereby driving the tripping mechanism to perform a tripping action and disconnect the switch; The trip control circuit includes: a leakage detection module, a control module, a power supply module, a voltage reduction module, a switch module and an energy storage module; The leakage detection module is used to detect the leakage state of the protected circuit; The input end of the step-down module is connected to the output end of 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 connected to the leakage detection module and the control end of the switch module respectively, and the control module is used to control the on-off state of the switch module according to the leakage state; The energy storage module is respectively connected to the output end of the power module and the two ends of the trip coil; 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 trip control circuit according to claim 1, characterized in that: The control module includes: a first step-down unit, wherein an input end of the first step-down unit is connected to an output end of the power module; A leakage protection unit, wherein the input end of the leakage protection unit is connected to the leakage detection module, and the power supply end of the leakage protection unit is connected to the output end of the first step-down unit; the leakage protection unit is used to control the potential output by the output end of the leakage protection unit according to the leakage state; A potential control unit, wherein the control end of the potential control unit is connected to the output end of the leakage protection unit, the first input end of the potential control unit is connected to the output end of the power supply module, the second input end of the potential control unit is grounded, and the output end of the potential control unit is connected to the control end of the switch module; the potential control unit is used to control the output of the potential connected to the first input end or the second input end of the potential control unit according to the potential of its control end.

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

4. The trip 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 switch module, and the second end of the switch module is grounded; The energy storage module includes: a second step-down unit, wherein an input end of the second step-down unit is connected to an output end of the power module; an energy storage unit, wherein a first end of the energy storage unit is respectively connected to the output end of the second step-down unit and the first end of the trip coil, and a second end of the energy storage unit is grounded; A switch unit, wherein the control end of the switch unit is connected to the output end of the second step-down unit, the input end of the switch unit is grounded, and the output end of the switch unit is connected to the second end of the trip coil.

5. The trip 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, a first end of the third capacitor is connected to the first end of the energy storage unit, and a second end of the third capacitor is connected to the second end of the energy storage unit; The switch unit includes: an optical coupler, wherein a first end of a transmitting part of the optical coupler is connected to a control end of the switch unit, a second end of the transmitting part is grounded, a first end of a receiving part of the optical coupler is connected to an input end of the switch unit, and a second end of the receiving part is connected to an output end of the switch unit; the optical coupler is configured such that the receiving part is turned off when the transmitting part emits light, and the receiving part is turned on when the transmitting part does not emit light.

6. The trip 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 end of the second step-down unit and the first end of the third capacitor; the second diode and the third resistor are connected in series between the first end of the third capacitor and the first end of the trip coil; The switch unit further includes: a fourth capacitor and a first voltage regulator tube, both connected between the control end of the switch unit and the ground.

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

9. The trip control circuit according to claim 1, characterized in that: The power module includes: a rectifier bridge, the input end of the rectifier bridge is connected to the AC power supply, and the output end of the rectifier bridge serves as the output end of the power module; and / or, The switch module includes: a thyristor; the thyristor and the trip coil are connected in series between the output end of the step-down module and the ground, and the control electrode of the thyristor serves as the control end of the switch module; and / or, The trip control circuit further includes: a fifth resistor, wherein a first end of the fifth resistor is connected to the output end of the step-down module, and the trip coil and the switch module are connected in series between a second end of the fifth resistor and ground; The 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 tripper, and a tripping control circuit according to any one of claims 1 to 9.

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