Circuit module for three-phase four-wire residual-current circuit breaker and residual-current circuit breaker

Abstract

The utility model discloses a circuit module for a three-phase four-wire residual-current circuit breaker and the residual-current circuit breaker, and relates to the technical field of low-voltage electric appliances, and the circuit module comprises an input module and a surge absorption module. The input module is used for being connected with an external power supply and comprises three phase input interfaces and a neutral input interface. The surge absorption module is electrically connected with the input module. The surge absorption module can absorb surge energy generated by the circuit module in the working process. Wherein the surge absorption module comprises three first piezoresistors, the three phase input interfaces are respectively connected with one first piezoresistor, and the three first piezoresistors are simultaneously connected to the neutral input interface. According to the invention, not only is the requirement of directly adding piezoresistors to two phases in the prior art reduced, but also the number and the size of the required piezoresistors are remarkably reduced, so that the safety of the circuit is ensured, and meanwhile, the cost is saved and the space is optimized.

Description

Technical Field

[0001] This application relates to the field of low-voltage electrical technology, and in particular to a circuit module and a residual current circuit breaker for a three-phase four-wire residual current circuit breaker. Background Technology

[0002] A three-phase four-wire residual current circuit breaker (RCCB) is a device specifically designed to protect power systems from damage caused by leakage current and short circuits. This device is particularly suitable for three-phase four-wire power systems, effectively monitoring and controlling current flow to ensure the safe and stable operation of the power system.

[0003] In traditional applications, varistors are typically installed directly between two phases to address potential surges in power systems. This is done so that the varistor can respond quickly to sudden voltage spikes, thus protecting the power system from damage.

[0004] However, adding a varistor will increase costs and take up more space. Utility Model Content

[0005] This application provides a circuit module and a residual current circuit breaker for a three-phase four-wire residual current circuit breaker. It not only reduces the need to directly install varistors on two phases in traditional technology, but also significantly reduces the number and volume of varistors required, thereby achieving cost savings and space optimization while ensuring circuit safety.

[0006] In one aspect, this application provides a circuit module for a three-phase four-wire residual current circuit breaker, the circuit module including an input module and a surge absorption module.

[0007] The input module is used to connect to an external power supply. The input module includes three phase input interfaces and one neutral input interface.

[0008] The surge absorption module is electrically connected to the input module and can absorb the surge energy generated by the circuit module during operation.

[0009] The surge absorption module includes three first varistors. Each of the three phase input interfaces is connected to a first varistor, and all three first varistors are simultaneously connected to the neutral input interface.

[0010] The main function of the input module is to connect to an external power supply. To meet the requirements of a three-phase four-wire system, the input module is carefully designed with three phase input interfaces and one neutral input interface to ensure stable power supply and balanced current distribution.

[0011] The surge absorption module works in conjunction with the input module via electrical connection. The main function of the surge absorption module is to effectively absorb and process potential surge energy during the operation of the circuit module, thereby protecting the circuit from damage.

[0012] The surge absorption module includes three first varistors, each connected to a phase input interface. These three first varistors not only operate independently but are also connected together to the neutral input interface, forming an effective surge energy processing network.

[0013] The three primary varistors, named RV1, RV2, and RV3, work together to absorb surge current. By connecting the three varistors in parallel to the neutral input interface (N common point), this design not only reduces the need for directly installing varistors on two phases as in traditional technologies, but also significantly reduces the number and size of the required varistors. This ensures circuit safety while also achieving cost savings and space optimization.

[0014] In some examples, the circuit module also includes an AC rectifier module connected to the input module. The AC rectifier module includes three rectifier sub-modules connected to the phase input interface in a one-to-one correspondence.

[0015] An AC rectifier module converts alternating current (AC) to direct current (DC). More specifically, an AC rectifier module consists of three rectifier sub-modules, each connected to a specific phase input interface of the input module. Each sub-module corresponds to a specific phase input interface, ensuring efficient circuit operation and stable current conversion.

[0016] In some examples, the rectifier submodule is a half-wave rectifier module or a full-wave rectifier module.

[0017] All three rectifier submodules are half-wave rectifier modules. Alternatively, all three rectifier submodules are full-wave rectifier modules, with some submodules being half-wave rectifier modules and others being full-wave rectifier modules.

[0018] A half-wave rectifier module allows alternating current to flow in only one direction, so it only converts one half-cycle of the alternating current (positive or negative half-cycle) and discards the other half-cycle. This rectification efficiency is low because it only utilizes half of the energy of the alternating current.

[0019] Full-wave rectifier modules allow alternating current to flow in both positive and negative directions. They convert both the positive and negative half-cycles of alternating current into direct current, resulting in higher efficiency and less pulsation in the output direct current.

[0020] The above three scenarios can be understood as follows: all three rectifier submodules are half-wave rectifier modules, or all are full-wave rectifier modules, or some of them are half-wave rectifier modules while others are full-wave rectifier modules.

[0021] Half-wave rectification is a rectification method that allows only one half-cycle of the alternating current to pass through. Full-wave rectification is a rectification method that allows both the positive and negative half-cycles of the alternating current to pass through.

[0022] In some examples, all three rectifier submodules are half-wave rectifier modules. The AC rectifier module includes a first diode, a second diode, a third diode, a fourth diode, and a rectifier resistor. The three phase input interfaces are the first interface, the second interface, and the third interface, respectively.

[0023] The first end of the first diode is connected to the first interface, and the second end of the first diode is directly or indirectly connected to the rectifier resistor.

[0024] The first end of the second diode is connected to the second interface, and the second end of the second diode is directly or indirectly connected to the rectifier resistor.

[0025] The first end of the third diode is connected to the third interface, and the second end of the third diode is directly or indirectly connected to the rectifier resistor.

[0026] The first terminal of the fourth diode is connected to the neutral input interface, and the second terminal of the fourth diode is directly or indirectly connected to the rectifier resistor.

[0027] In this circuit module, when AC power is input through the first, second, and third interfaces, the first, second, and third diodes respectively perform half-wave rectification of the AC power in their respective phases. The rectified current passes through the rectifier resistor, thereby generating a DC voltage across the rectifier resistor. The fourth diode is responsible for performing half-wave rectification of the AC power in the neutral line, ensuring the balance of the entire circuit. In this way, the residual current circuit breaker can effectively convert AC power to DC power and can detect and respond to abnormal currents in the circuit to protect the safe operation of the circuit.

[0028] In some examples, the first and third diodes are forward-biased, the second and fourth diodes are reverse-biased, and the second terminals of the first and third diodes are both connected to the first terminal of the rectifier resistor, and the second terminals of the second and fourth diodes are both connected to the second terminal of the rectifier resistor.

[0029] In this context, "forward connection" refers to a connection method in which the diode can be connected unidirectionally from the input module to the output module.

[0030] In this circuit module, when AC power is input through the first, second, and third interfaces, the first, second, and third diodes respectively perform half-wave rectification of the AC power in their respective phases. The rectified current passes through the rectifier resistor, thereby generating a DC voltage across the rectifier resistor. The fourth diode is responsible for performing half-wave rectification of the AC power in the neutral line, ensuring the balance of the entire circuit. In this way, the residual current circuit breaker can effectively convert AC power to DC power and can detect and respond to abnormal currents in the circuit to protect the safe operation of the circuit.

[0031] In some examples, the circuit module also includes a secondary absorption module electrically connected to the side of the AC rectifier module away from the surge absorption module. The secondary absorption module includes a trip coil and a CBB capacitor. The secondary absorption module is used to absorb the remaining surge energy and suppress voltage ripple after rectification, while also helping to reduce EMC conducted interference noise signals.

[0032] The circuit module also includes a secondary absorption module, which is electrically connected to the other side of the AC rectifier module, away from the surge absorption module. This secondary absorption module consists of a trip coil and a CBB capacitor, and its main function is to further absorb the remaining surge energy that was not completely absorbed after the rectification process, and to suppress voltage ripple.

[0033] In some examples, the circuit module also includes a trip drive module, a DC high voltage buck module, a power ripple absorption module, and an energy storage module.

[0034] The trip drive module is electrically connected to the secondary absorption module. The trip drive module includes two thyristors connected in series, which are used to drive the trip unit.

[0035] The DC high voltage buck module is electrically connected to the trip drive module. The DC high voltage buck module includes interconnected buck resistors, field-effect transistors and a first transient voltage suppressor. The DC high voltage buck module can convert high voltage DC to lower voltage DC.

[0036] The power ripple absorption module is electrically connected to the DC high voltage step-down module. The power ripple absorption module includes a second transient voltage suppressor and a third transient voltage suppressor connected in series to absorb transient voltages.

[0037] The energy storage module is connected in series with the DC high voltage step-down module and in parallel with the power supply ripple absorption module. The energy storage module includes two electrolytic capacitors connected in series: a first electrolytic capacitor and a second electrolytic capacitor. The energy storage module is capable of storing pulsating voltage.

[0038] The trip drive module and the secondary absorption module are interconnected by electrical connection. The trip drive module itself consists of two thyristors connected in series. The main function of these two thyristors is to drive the trip unit, ensuring that it can respond quickly and perform the tripping action when the circuit is abnormal.

[0039] The DC high-voltage buck module and the trip drive module work together via an electrical connection. The DC high-voltage buck module consists of a series of interconnected electronic components, including a buck resistor, a field-effect transistor, and a first transient voltage suppressor. These components work together to enable the DC high-voltage buck module to effectively convert the input high-voltage DC into a lower-voltage DC output to meet the voltage requirements of subsequent circuits.

[0040] The power ripple absorption module is electrically connected to the DC high-voltage buck module, ensuring stable current transmission between the two. The power ripple absorption module includes a second transient voltage suppressor and a third transient voltage suppressor connected in series. These two components work together to absorb and suppress transient voltage fluctuations in the circuit, thereby protecting the circuit from damage caused by transient voltages.

[0041] The energy storage module is connected in series with the DC high-voltage step-down module and in parallel with the power supply ripple absorption module. The energy storage module consists of two electrolytic capacitors connected in series, a first electrolytic capacitor and a second electrolytic capacitor. This design allows the energy storage module to effectively store pulsating voltage, thus stabilizing the voltage in the circuit.

[0042] In some examples, the DC high voltage buck module includes at least one resistor, a field-effect transistor, and a fourth transient voltage suppressor.

[0043] Part of the resistor is located between the fourth transient voltage suppressor and the gate of the field-effect transistor.

[0044] In some examples, the circuit module also includes a detection module that is indirectly electrically connected to the energy storage module. The detection module is mounted on a circuit board or is part of a current transformer.

[0045] The detection module is not directly connected to the energy storage module, but rather through an indirect connection. Furthermore, the detection module is designed to be mounted on a circuit board or integrated into a current transformer.

[0046] This design makes the circuit module more functional, enabling real-time monitoring and detection of power usage, thereby improving the efficiency and safety of the entire circuit system.

[0047] By integrating the detection module into the circuit board or current transformer, additional connection components can be reduced, circuit design can be simplified, production costs can be reduced, and the stability and reliability of the system can be improved.

[0048] Secondly, this application provides a residual current circuit breaker, including at least a portion of the circuit module described above for a three-phase four-wire residual current circuit breaker.

[0049] The leakage circuit breaker with the above circuit module can have higher safety and stability. Specifically, after the surge absorption module is connected to the input module, it can be used to absorb the surge energy generated when the circuit is working and protect the circuit from damage.

[0050] Specifically, the surge absorption module includes three first varistors, each connected to a phase input interface. These three first varistors not only operate independently but are also connected together to the neutral input interface, forming an effective surge energy processing network.

[0051] The three primary varistors, named RV1, RV2, and RV3, work together to absorb surge current. By connecting the three varistors in parallel to the neutral input interface (N common point), this design not only reduces the need for directly installing varistors on two phases as in traditional technologies, but also significantly reduces the number and size of the required varistors. This ensures circuit safety while also achieving cost savings and space optimization. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the examples or prior art description will be briefly introduced below. Obviously, the drawings described below are only some examples of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of the structure of a half-wave rectifier module used in a three-phase four-wire residual current circuit breaker in the prior art.

[0054] Figure 2 This is a schematic diagram of the AC rectifier module in a circuit module for a three-phase four-wire residual current circuit breaker, as shown in one example of this application.

[0055] Figure 3 This is a schematic diagram of the overall structure of a circuit module for a three-phase four-wire residual current circuit breaker in one example of this application.

[0056] Figure 4 This is a schematic diagram of the input module in a circuit module for a three-phase four-wire residual current circuit breaker, as shown in one example of this application.

[0057] Figure 5 This is a partial structural diagram of the surge absorption module and AC rectifier module in a circuit module for a three-phase four-wire residual current circuit breaker in one example of this application.

[0058] Figure 6 This is a partial structural diagram of the tripping drive module in a circuit module for a three-phase four-wire residual current circuit breaker, as shown in one example of this application.

[0059] Figure 7 This is a partial structural diagram of the DC high-voltage step-down module in a circuit module for a three-phase four-wire residual current circuit breaker, as shown in one example of this application.

[0060] Figure 8 This is a partial structural diagram of the power ripple absorption module and the energy storage module in the circuit module of a three-phase four-wire residual current circuit breaker in one example of this application.

[0061] Figure label:

[0062] 100. Input Module; 110. Phase Input Interface; 111. First Interface; 112. Second Interface; 113. Third Interface; 120. Neutral Input Interface; 130. AT Interface; 140. Test Interface; 200. Surge Absorption Module; 210. First Varistor; 300. AC Rectifier Module; 310. First Diode; 320. Second Diode; 330. Third Diode; 340. Fourth Diode; 350. Rectifier Resistor; 400. Secondary Absorption Module; 410. Trip Coil; 500. Trip Drive Module; 600. DC High Voltage Step-Down Module; 700. Power Ripple Absorption Module; 800. Energy Storage Module; 900. Switching Power Supply and Peripheral Configuration Circuit; 1000. Type B Detection Module Interface; 1100. Type B Detection Module; 1200. Current Transformer. Detailed Implementation

[0063] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and examples. It should be understood that the specific examples described herein are merely illustrative and not intended to limit the scope of this application.

[0064] In circuit modules used in three-phase four-wire residual current circuit breakers (RCCBs) of related technologies, the common buck converter chips have a withstand voltage between 600-900V. In actual secondary power distribution to terminal applications, the power supply voltage fluctuates significantly. The maximum voltage after three-phase rectification is around 678V. The maximum design margin for the chip is only 222V. A reasonable safety margin should be above 350V. The reverse electromotive force of the power supply inductor or surges during operation can cause overvoltage failure of the switching power supply chip. Meanwhile, the 900V switching power supply chip is an SMD8C, making small-size RCBO layout difficult. To address these issues, adding a MOSFET for step-down can control the input voltage of the switching power supply chip within a reasonable range. This application can solve the problem of insufficient withstand voltage of current buck converter chips and increase reliability.

[0065] The circuit of this invention mainly solves the power supply design problem in low-cost, space-efficient leakage current protection device product systems.

[0066] Because the leakage current requirement is relatively small, conventional half-wave rectification is sufficient for the operation of subsequent circuits. Furthermore, half-wave rectification helps reduce the effective value of the input voltage of the switching power supply, thereby reducing the high-voltage time on the MOSFETs and switching power supply chips. However, in common practical applications of half-wave rectification, if the N-terminal is disconnected due to a fault or is not connected, the half-wave rectification circuit will fail, causing the leakage current protection circuit to malfunction. It also fails to operate in either three-phase or two-phase power supply scenarios. The improved version works in all scenarios except for two-phase power supply, improving adaptability to practical applications.

[0067] This invention primarily addresses the power supply design of low-cost, space-constrained leakage current protection (RCD) systems. Common AC-type RCDs, particularly Type A, utilize electronic step-down technology, requiring relatively low power but consuming significant power. With the development of the new energy market, the demand for Type B RCDs and Type A + DC 6mA RCDs is gradually increasing. Type B RCDs involve a wider range of detection items, and the current market primarily utilizes microcontrollers to handle various RCD types, requiring up to 50mA of power. Ordinary resistor-based step-down circuits are space-consuming and have large resistor volumes, failing to meet the space requirements of small RCD applications. Several common switching power supply modes are discussed. BUCK step-down switching power supplies offer advantages in terms of fewer components, cost, and compact electronic component configuration. They simultaneously meet the power requirements of the Type B RCD drive circuit, amplifier circuit, filter circuit, operational circuit, and control output circuit.

[0068] To solve the above technical problems, please refer to Figures 1-8 As shown, the first aspect of this application proposes a circuit module for a three-phase four-wire residual current circuit breaker, which not only reduces the need to directly install varistors on two phases in the traditional technology, but also significantly reduces the number and volume of varistors required, thereby achieving cost savings and space optimization while ensuring circuit safety.

[0069] This circuit design includes several key components, featuring a power input interface that receives external power and supplies energy to the entire circuit. Surge absorption is incorporated to protect the circuit from damage caused by sudden voltage spikes. Furthermore, an AC rectification section converts the input AC power into DC power, providing a stable DC power supply for subsequent circuits.

[0070] The trip unit, combined with surge and voltage ripple absorption circuitry, ensures rapid power disconnection in abnormal situations, protecting the circuit. The trip drive circuit controls the trip unit's operation, ensuring it executes its task accurately when needed. The DC high-voltage step-down circuit reduces the DC voltage to a level suitable for circuit operation.

[0071] The power supply ripple absorption stage further stabilizes the power output, reducing the impact of voltage fluctuations on the circuit. The energy storage section is responsible for storing energy in the circuit for unforeseen needs. The switching power supply section provides an efficient way to convert and manage power. The Type B leakage current detection module interface and the Type B leakage current detection module work together to monitor leakage current in the circuit, ensuring electrical safety. The current transformer 1200 is used to detect the current magnitude in the circuit, providing necessary information for stable circuit operation.

[0072] Reference Figure 2 and Figure 3 As shown, in some instances, this application provides a circuit module for a three-phase four-wire residual current circuit breaker, the circuit module including an input module 100 and a surge absorption module 200.

[0073] The input module 100 is used to connect to an external power supply. The input module 100 includes three phase input interfaces 110 and one neutral input interface 120.

[0074] The surge absorption module 200 is electrically connected to the input module 100, and the surge absorption module 200 can absorb the surge energy generated by the circuit module during operation.

[0075] The surge absorption module 200 includes three first varistors 210, each of the three phase input interfaces 110 is connected to a first varistor 210, and the three first varistors 210 are simultaneously connected to the neutral input interface 120.

[0076] The main function of the input module 100 is to connect to an external power supply. To meet the requirements of a three-phase four-wire system, the input module 100 is carefully designed with three phase input interfaces 110 and one neutral input interface 120 to ensure stable power supply and balanced current distribution.

[0077] The surge absorption module 200 is electrically connected to the input module 100. The main function of the surge absorption module 200 is to effectively absorb and process potential surge energy during the operation of the circuit module, thereby protecting the circuit from damage.

[0078] The surge absorption module 200 includes three first varistors 210, each of which is connected to a phase input interface 110. These three first varistors 210 not only operate independently, but are also connected together to the neutral input interface 120, forming an effective surge energy processing network.

[0079] The three first varistors 210 are named RV1, RV2, and RV3, respectively, and together they are responsible for absorbing surge current. By connecting the three varistors in parallel to the neutral input interface 120 (N common point), this design not only reduces the need for directly installing varistors on two phases as in traditional technology, but also significantly reduces the number and size of the required varistors. Thus, while ensuring circuit safety, it also achieves cost savings and space optimization.

[0080] After the surge absorption module 200 is connected to the input module 100, it can be used to absorb the surge energy generated when the circuit is working, and protect the circuit from damage.

[0081] A three-phase four-wire residual current circuit breaker (RCCB) is a device used to protect power systems from damage caused by leakage current and short circuits. It is suitable for three-phase four-wire power systems. The input module 100 is the part of the circuit module responsible for receiving external signals or power, and typically includes interfaces and necessary conversion circuits.

[0082] Surge absorption module 200 refers to a circuit section specifically designed to absorb and suppress transient high-energy surges generated in a circuit due to abnormal conditions (such as lightning strikes, switching operations, etc.). A varistor is an electronic component that changes its resistance value in response to variations in the voltage applied across it, used to protect circuits from overvoltage damage.

[0083] In some examples, input module 100 also includes an AT interface 130 and / or a Test interface 140. The AT interface connects to phase A, and the Test1 and Test2 interfaces are terminals for test buttons on the residual current device (RCD). An external switch connects phase A to the N-phase circuit via a resistor RT. This simulates a leakage current condition, thus testing that the circuit functions correctly.

[0084] In some examples, the circuit module also includes an AC rectifier module 300, which is connected to the input module 100. The AC rectifier module 300 includes three rectifier sub-modules, which are connected to the phase input interface 110 in a one-to-one correspondence.

[0085] The circuit module includes not only the input module 100 but also an AC rectifier module 300. The AC rectifier module 300 converts AC power to DC power. More specifically, the AC rectifier module 300 consists of three rectifier sub-modules, each connected to a phase input interface 110 of the input module 100. Each rectifier sub-module corresponds to a specific phase input interface 110, ensuring efficient circuit operation and stable current conversion.

[0086] The AC rectifier module 300 is a circuit assembly used to convert alternating current (AC) to direct current (DC). It contains specialized electronic components, such as diodes, to achieve this conversion. A rectifier submodule is a sub-component of the AC rectifier module 300 and typically contains rectifier elements, such as diodes, to perform single-phase AC-to-DC conversion.

[0087] Furthermore, each rectifier submodule is equipped with a rectifier diode for converting AC to DC. Additionally, the circuit module may include a filter module connected to the AC rectifier module 300 to filter out high-frequency noise in the rectified DC. The filter module may consist of capacitors and inductors to achieve effective filtering. In some embodiments, the filter module also includes a voltage regulator to ensure the stability of the output voltage. Through the coordinated operation of these components, the circuit module can provide a stable and clean power supply to the three-phase four-wire residual current circuit breaker, thereby improving the reliability and performance of the entire system.

[0088] In some examples, the rectifier submodule is a half-wave rectifier module or a full-wave rectifier module.

[0089] All three rectifier submodules are half-wave rectifier modules. Alternatively, all three rectifier submodules are full-wave rectifier modules, with some submodules being half-wave rectifier modules and others being full-wave rectifier modules.

[0090] A half-wave rectifier module allows alternating current to flow in only one direction, so it only converts one half-cycle of the alternating current (positive or negative half-cycle) and discards the other half-cycle. This rectification efficiency is low because it only utilizes half of the energy of the alternating current.

[0091] Full-wave rectifier modules allow alternating current to flow in both positive and negative directions. They convert both the positive and negative half-cycles of alternating current into direct current, resulting in higher efficiency and less pulsation in the output direct current.

[0092] The above three scenarios can be understood as follows: all three rectifier submodules are half-wave rectifier modules, or all are full-wave rectifier modules, or some of them are half-wave rectifier modules while others are full-wave rectifier modules.

[0093] Half-wave rectification is a rectification method that allows only one half-cycle of the alternating current to pass through. Full-wave rectification is a rectification method that allows both the positive and negative half-cycles of the alternating current to pass through.

[0094] The rectifier submodules can be combinations with different rectification characteristics; for example, one module may be a half-wave rectifier while the other two are full-wave rectifiers. This design allows the system to be flexibly adjusted to meet different application requirements, achieving optimal performance and efficiency. Furthermore, the output of each rectifier submodule can be controlled independently, providing finer-grained circuit management. In this way, the residual current circuit breaker (RCCB) can respond more precisely to changes in the circuit, ensuring system stability and safety.

[0095] In some examples, all three rectifier submodules are half-wave rectifier modules. The AC rectifier module 300 includes a first diode 310, a second diode 320, a third diode 330, a fourth diode 340, and a rectifier resistor 350. The three phase input interfaces 110 are the first interface 111, the second interface 112, and the third interface 113, respectively.

[0096] The first end of the first diode 310 is connected to the first interface 111, and the second end of the first diode 310 is directly or indirectly connected to the rectifier resistor 350.

[0097] The first end of the second diode 320 is connected to the second interface 112, and the second end of the second diode 320 is directly or indirectly connected to the rectifier resistor 350.

[0098] The first end of the third diode 330 is connected to the third interface 113, and the second end of the third diode 330 is directly or indirectly connected to the rectifier resistor 350.

[0099] The first terminal of the fourth diode 340 is connected to the neutral input interface 120, and the second terminal of the fourth diode 340 is directly or indirectly connected to the rectifier resistor 350.

[0100] In this circuit module, when AC power is input through the first, second, and third interfaces 113, the first, second, and third diodes 330 respectively perform half-wave rectification of the AC power in their respective phases. The rectified current passes through the rectifier resistor 350, thereby generating a DC voltage across the rectifier resistor 350. The fourth diode 340 is responsible for performing half-wave rectification of the AC power in the neutral line, ensuring the balance of the entire circuit. In this way, the residual current circuit breaker can effectively convert AC power to DC power and can detect and respond to abnormal currents in the circuit to protect the safe operation of the circuit.

[0101] All three rectifier submodules can be classified as half-wave rectifier modules. Specifically, the AC rectifier module 300 consists of a series of key components, including but not limited to a first diode 310, a second diode 320, a third diode 330, a fourth diode 340, and a rectifier resistor 350. These components work together to convert AC to DC. Furthermore, the module is equipped with three phase input interfaces 110, designated as first interface 111, second interface 112, and third interface 113, to facilitate AC input of different phases.

[0102] In terms of the connection of these components, one end of the first diode 310 is precisely connected to the first interface 111, while the other end is directly or indirectly connected to the rectifier resistor 350 through other circuit elements. This connection method ensures that the current can flow along a predetermined path, thereby completing the rectification process.

[0103] Similarly, one end of the second diode 320 is connected to the second interface 112, while its second end is directly or indirectly connected to the rectifier resistor 350 through other circuit elements. This design ensures that the AC current of the second phase can also be effectively rectified.

[0104] The third diode 330 also follows this design principle, with one end connected to the third interface 113, and the other end connected directly or indirectly to the rectifier resistor 350 through other circuit elements. This layout ensures that the AC power of the third phase can also be converted into DC power.

[0105] One end of the fourth diode 340 is connected to the neutral input interface 120, while the other end is directly or indirectly connected to the rectifier resistor 350 through other circuit components. This connection method is crucial for the stable operation of the entire AC rectifier module 300, ensuring that the current in the neutral line is also correctly rectified.

[0106] In some examples, the first diode 310 and the third diode 330 are forward connected, the second diode 320 and the fourth diode 340 are reverse connected, and the second terminals of the first diode 310 and the third diode 330 are both connected to the first terminal of the rectifier resistor 350, and the second terminals of the second diode 320 and the fourth diode 340 are both connected to the second terminal of the rectifier resistor 350.

[0107] In this context, "forward connection" refers to a connection method in which the diode can be unidirectionally connected from the input module 100 to the output module.

[0108] The first diode 310 and the third diode 330 are forward-biased, allowing current to flow smoothly from the input module 100 to the output module without obstruction. Meanwhile, the second diode 320 and the fourth diode 340 are reverse-biased, meaning that current is impeded when returning from the output module to the input module 100, ensuring unidirectional current flow. Furthermore, the second terminals of the first diode 310 and the third diode 330 are connected to the first terminal of the rectifier resistor 350, while the second terminals of the second diode 320 and the fourth diode 340 are connected to the second terminal of the rectifier resistor 350. This connection method facilitates current rectification.

[0109] In these examples, a forward connection is defined as a diode that allows current to flow unidirectionally from the input module 100 to the output module, ensuring smooth current transmission. Conversely, a reverse connection means that the diode allows current to flow unidirectionally from the output module to the input module 100, preventing reverse current flow and thus protecting the circuit from damage.

[0110] In addition, the circuit module includes a control circuit connected to the rectifier resistor 350Ω, which adjusts the diode's conduction state according to the phase of the input AC current. The control circuit is designed to enable precise control of the residual current circuit breaker in different operating modes, thereby improving the safety and reliability of the entire circuit.

[0111] In practical applications, circuit modules can be integrated into residual current circuit breakers (RCCBs) to protect the circuit. When a leakage or short circuit is detected, the control circuit responds quickly, cutting off the power supply to prevent fires or electric shocks caused by excessive current. Through this design, the RCCB not only protects the circuit from damage but also ensures user safety.

[0112] In some examples, the circuit module also includes a secondary absorption module 400 electrically connected to the side of the AC rectifier module 300 away from the surge absorption module 200. The secondary absorption module 400 includes a trip coil 410 and a CBB capacitor. The secondary absorption module 400 is used to absorb the remaining surge energy and suppress voltage ripple after rectification.

[0113] The circuit module also includes a secondary absorption module 400, which is electrically connected to the other side of the AC rectifier module 300, away from the surge absorption module 200. This secondary absorption module 400 consists of a trip coil 410 and a CBB capacitor. Its main function is to further absorb the remaining surge energy that was not completely absorbed after the rectification process, and to suppress voltage ripple.

[0114] The rectified voltage passes through the trip coil 410coil1, and then the CBB capacitor absorbs any remaining surge energy that was not fully absorbed at the front end. The CBB capacitor plays a role in absorbing noise generated by the switching power supply during switching operations. Capacitors are commonly used in circuit design to store charge, smooth voltage fluctuations, and filter noise.

[0115] CBB capacitors (Cast Polypropylene Film Capacitors, CBB) are a common type of non-polar capacitor, favored for their excellent performance and wide range of applications. CBB capacitors, also known as polypropylene metallized film capacitors, are constructed using a polypropylene plastic film as the dielectric material and a metallized film as the electrode. These capacitors exhibit good frequency characteristics and can operate stably in high-frequency circuits.

[0116] The CBB capacitor mentioned above is used to absorb the electrical noise generated during the instantaneous switching of the power supply. Capacitors are commonly used in circuits to store charge, smooth voltage fluctuations, and filter noise. In this context, the role of the CBB is to help reduce or eliminate the electrical noise generated during the instantaneous switching of the power supply, thereby improving the stability and reliability of the circuit.

[0117] In some examples, the circuit module also includes a trip drive module 500, a DC high voltage step-down module 600, a power ripple absorption module 700, and an energy storage module 800.

[0118] The trip drive module 500 is electrically connected to the secondary absorption module 400. The trip drive module 500 includes two thyristors connected in series, which are used to drive the trip unit.

[0119] The circuit modules described above are not limited to including the trip drive module 500, the DC high voltage step-down module 600, the power ripple absorption module 700, and the energy storage module 800; they may also include other functional modules to meet different application requirements.

[0120] The trip drive module 500 and the secondary absorption module 400 are interconnected by electrical connection. The trip drive module 500 itself consists of two thyristors connected in series. The main function of these two thyristors is to drive the trip unit to ensure that it can respond quickly and perform the trip action when the circuit is abnormal.

[0121] In the design of the trip unit drive circuit, two thyristors, VT1 and VT2, are used to form the drive circuit. This dual-thyristor configuration helps improve the circuit's driving capability when facing surge current, thereby enhancing the overall stability and reliability of the circuit. The trigger electrode of the thyristors is controlled by the leakage current detection module to ensure timely triggering of the tripping action when leakage current is detected. The function of diode D10 is to prevent the current from the trigger electrode of the high-voltage thyristor from flowing back to the type B leakage current detection module, thereby avoiding damage to the module due to current surges. In addition, resistors R8 to R11 are set to achieve voltage balance among the thyristors, ensuring that the voltage distribution across each thyristor is uniform during operation, further improving the stability and safety of the circuit.

[0122] The DC high voltage step-down module 600 is electrically connected to the trip drive module 500. The DC high voltage step-down module 600 includes a step-down resistor, a field-effect transistor and a first transient voltage suppressor connected to each other. The DC high voltage step-down module 600 can convert high voltage DC to lower voltage DC.

[0123] The DC high-voltage buck module 600 and the trip drive module 500 work together via an electrical connection. The DC high-voltage buck module 600 consists of a series of interconnected electronic components, including a buck resistor, a field-effect transistor, and a first transient voltage suppressor. These components work together to enable the DC high-voltage buck module 600 to effectively convert the input high-voltage DC power into a lower-voltage DC power output to meet the voltage requirements of subsequent circuits.

[0124] The high-voltage buck circuit mainly consists of resistors R1 and R15, a metal-oxide-semiconductor field-effect transistor (MOSFET) Q1, and a transient voltage suppressor (TVS4). For resistor R1, a wire-wound fuse is recommended. This design effectively melts the fuse in case of a short circuit at the downstream end, protecting the circuit from damage. This type of resistor also exhibits high reliability in resisting surge impacts. When the voltage in the circuit exceeds the set value, the transient voltage suppressor TVS4 is triggered to conduct through resistor R15, causing the gate (G) level of the MOSFET to be pulled low, thus turning off the MOSFET and cutting off current flow. When the voltage is lower than the set value, TVS4 is in the off state, and the gate (G) of the MOSFET is at a high level, thereby opening the drain (D) and source (S) of the MOSFET, allowing current to flow smoothly to the downstream circuit.

[0125] The power ripple absorption module 700 is electrically connected to the DC high voltage step-down module 600. The power ripple absorption module 700 includes a second transient voltage suppressor and a third transient voltage suppressor connected in series to absorb transient voltages.

[0126] The power ripple absorption module 700 is electrically connected to the DC high-voltage buck module 600, ensuring stable current transmission between the two. The power ripple absorption module 700 includes a second transient voltage suppressor and a third transient voltage suppressor connected in series. These two components work together to absorb and suppress transient voltage fluctuations in the circuit, thereby protecting the circuit from damage caused by transient voltages.

[0127] By connecting transient voltage suppressors TVS1 and TVS2 in series, the absorption power of the entire circuit for transient voltages can be effectively improved. This configuration allows each transient voltage suppressor to share the impact of transient voltages, thereby extending the lifespan of the entire power supply ripple absorption module 700 and improving the stability and reliability of the circuit.

[0128] The energy storage module 800 is connected in series with the DC high voltage step-down module 600 and in parallel with the power ripple absorption module 700. The energy storage module 800 includes two electrolytic capacitors connected in series, namely a first electrolytic capacitor and a second electrolytic capacitor. The energy storage module 800 is capable of storing pulsating voltage.

[0129] The energy storage module 800 is connected in series with the DC high-voltage step-down module 600 and in parallel with the power ripple absorption module 700. The energy storage module 800 consists of two electrolytic capacitors connected in series, a first electrolytic capacitor and a second electrolytic capacitor. This design enables the energy storage module 800 to effectively store pulsating voltage, thereby stabilizing the voltage in the circuit.

[0130] Electrolytic capacitors C2 and C3 are configured to smooth the pulsating voltage at the energy storage front end. In this way, they can absorb and store unstable pulsating voltages from the power supply, thereby providing a more stable and clean voltage source for subsequent circuits.

[0131] In the above structure, the DC high-voltage buck module 600 is located at the input end of the circuit module. Its main function is to convert the input high-voltage DC power into low-voltage DC power suitable for the operation of subsequent circuits. This module typically includes a buck transformer and rectifier diodes to ensure the stability and safety of the output voltage.

[0132] The power ripple absorption module 700 is responsible for further reducing voltage ripple in the power output and improving power quality. It typically consists of inductors and capacitors, and uses a filter circuit to reduce voltage fluctuations, ensuring a smoother DC power supply to the load.

[0133] The energy storage module 800 is an indispensable part of the circuit module. It is usually composed of capacitors or inductors and is used to store energy in the circuit to meet the short-term energy demand during load changes or power outages. The presence of the energy storage module enables the circuit to maintain the continuity and stability of the output when faced with unstable power input.

[0134] The circuit module of this application also includes a switching power supply and peripheral configuration circuitry 900, wherein U1, C4, R3, R2, C5, D11, L2, D12, C6, and R4 form a BUCK step-down switching power supply circuit. A linear regulator U2, R6, C8, C9, C7, and TVS3 form a step-down circuit. This circuit design aims to provide an efficient and stable power conversion scheme to meet the precise control requirements of the residual current circuit breaker. The BUCK step-down switching power supply circuit achieves precise regulation of the input voltage through the rapid switching of its switching elements, ensuring the stability and reliability of the output voltage. The linear regulator further smooths the output voltage, reduces noise and ripple, and provides a clean power environment for sensitive electronic components. Through this combination, the circuit not only provides the required voltage level but also ensures stable performance under various operating conditions.

[0135] When discussing the switching power supply and its peripheral circuitry, we can see that components U1, C4, R3, R2, C5, D11, L2, D12, C6, and R4 together constitute a buck switching power supply circuit. This circuit, through the coordinated work of a series of electronic components, achieves the function of converting the input voltage into the desired output voltage. Furthermore, the linear regulator U2, together with components such as R6, C8, C9, C7, and TVS3, forms a buck circuit. This circuit further stabilizes and adjusts the output voltage through linear regulation, ensuring the stability and reliability of the power supply.

[0136] In some examples, the DC high-voltage buck module includes at least one resistor, a field-effect transistor, and a fourth transient voltage suppressor. A portion of the resistor is positioned between the fourth transient voltage suppressor and the gate of the field-effect transistor.

[0137] In some examples, the circuit module also includes a detection module that is indirectly electrically connected to the energy storage module 800, the detection module being mounted on a circuit board, or the detection module being part of the current transformer 1200.

[0138] The circuit module includes not only the energy storage module 800, but also a detection module. The detection module is not directly electrically connected to the energy storage module 800, but rather connected indirectly. Furthermore, the detection module is designed to be mounted on a circuit board, or it can be integrated into a portion of the current transformer 1200.

[0139] This design makes the circuit module more functional, enabling real-time monitoring and detection of power usage, thereby improving the efficiency and safety of the entire circuit system.

[0140] By integrating the detection module into the circuit board or the current transformer 1200, additional connection components can be reduced, circuit design can be simplified, production costs can be reduced, and the stability and reliability of the system can be improved.

[0141] The current transformer 1200 is an electrical device used to measure current in AC circuits. Its working principle utilizes electromagnetic induction (fluxgate) to convert large currents into smaller ones (by acquiring leakage signals such as AC leakage current, pulsating DC leakage current, and DC leakage current through excitation signals), facilitating the measurement and monitoring of current magnitude in the circuit while protecting the measuring equipment from damage by high voltage.

[0142] The design of the current transformer 1200 allows it to operate at different current levels to meet diverse application requirements. Operating on the principle of magnetic induction, it converts a large primary current into a small secondary current, thereby enabling current monitoring and control. The current transformer 1200 typically consists of a toroidal core made of a high-permeability material and coils wound around it. The primary coil is connected to the main circuit, while the secondary coil is connected to the detection circuit. This design not only improves measurement accuracy but also enhances circuit safety, as electrical isolation is achieved between the detection circuit and the main circuit. Furthermore, the output signal of the current transformer 1200 can be used for various protection functions, such as overload protection, short-circuit protection, and leakage current protection, ensuring the stable operation of the entire system.

[0143] The Type B detection module 1100 is designed for easy mounting on a PCBA (Printed Circuit Board Assembly) and can also be designed as part of the current transformer 1200. Users can flexibly select and configure the Type B detection module 1100 to meet specific application requirements, depending on the usage scenario and time constraints.

[0144] The flexibility and configurability of this module make it applicable to a wide variety of electronic devices and systems, from home appliances to industrial control systems. The Type B Detection Module 1100 provides accurate current detection.

[0145] Secondly, this application provides a residual current circuit breaker, including at least a portion of the circuit module described above for a three-phase four-wire residual current circuit breaker.

[0146] The leakage circuit breaker with the above circuit module can have higher safety and stability. Specifically, after the surge absorption module 200 is connected to the input module 100, it can be used to absorb the surge energy generated when the circuit is working and protect the circuit from damage.

[0147] Specifically, the surge absorption module 200 includes three first varistors 210, each of which is connected to a phase input interface 110. These three first varistors 210 not only operate independently but are also connected to the neutral input interface 120, forming an effective surge energy processing network.

[0148] The three first varistors 210 are named RV1, RV2, and RV3, respectively, and together they are responsible for absorbing surge current. By connecting the three varistors in parallel to the neutral input interface 120 (N common point), this design not only reduces the need for directly installing varistors on two phases as in traditional technology, but also significantly reduces the number and size of the required varistors. Thus, while ensuring circuit safety, it also achieves cost savings and space optimization.

[0149] In the accompanying drawings of this application, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0150] The above are merely preferred examples of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application shall be included within the scope of protection of this application.

Claims

1. A circuit module for a three-phase four-wire residual current circuit breaker, characterized in that, The circuit module comprises: an input module for connecting an external power supply, the input module comprising three phase input interfaces and a neutral input interface; a surge absorption module electrically connected to the input module, the surge absorption module being capable of absorbing surge energy generated by the circuit module during operation; wherein the surge absorption module comprises three first voltage-dependent resistors, one first voltage-dependent resistor being connected to each of the three phase input interfaces, and the three first voltage-dependent resistors being simultaneously connected to the neutral input interface; the circuit module further comprising an AC rectification module, the AC rectification module being connected to the input module, the AC rectification module comprising three rectification sub-modules, the rectification sub-modules being connected to the phase input interfaces one by one; the circuit module further comprising a secondary absorption module, the secondary absorption module being electrically connected to a side of the AC rectification module away from the surge absorption module, the secondary absorption module comprising a trip coil and a CBB capacitor, the secondary absorption module being used to absorb residual surge energy and suppress voltage ripple after rectification.

2. The circuit module for a three-phase, four-wire ground fault circuit interrupter of claim 1, wherein, The rectification sub-modules are half-wave rectification modules or full-wave rectification modules; all of the three rectification sub-modules are half-wave rectification modules, or all of the three rectification sub-modules are full-wave rectification modules, or some of the rectification sub-modules are half-wave rectification modules, or some of the rectification sub-modules are full-wave rectification modules.

3. The circuit module for a three-phase, four-wire ground fault circuit interrupter of claim 2, wherein, all of the three rectification sub-modules are half-wave rectification modules, the AC rectification module comprising a first diode, a second diode, a third diode, a fourth diode and a rectification resistor, the three phase input interfaces being a first interface, a second interface and a third interface; a first end of the first diode is connected to the first interface, and a second end of the first diode is directly or indirectly connected to the rectification resistor; a first end of the second diode is connected to the second interface, and a second end of the second diode is directly or indirectly connected to the rectification resistor; a first end of the third diode is connected to the third interface, and a second end of the third diode is directly or indirectly connected to the rectification resistor; a first end of the fourth diode is connected to the neutral input interface, and a second end of the fourth diode is directly or indirectly connected to the rectification resistor.

4. The circuit module for a three-phase, four-wire ground fault circuit interrupter of claim 3, wherein, The first diode and the third diode are connected in forward direction, the second diode and the fourth diode are connected in reverse direction, and the second ends of the first diode and the third diode are both connected to a first end of the rectification resistor, and the second ends of the second diode and the fourth diode are both connected to a second end of the rectification resistor. wherein forward connection refers to a connection mode in which a diode can be unidirectionally communicated from the input module to the output module, and reverse connection refers to a connection mode in which a diode can be unidirectionally communicated from the output module to the input module.

5. The circuit module for a three-phase, four-wire ground fault circuit interrupter of claim 1, wherein, The circuit module further comprises: a trip drive module electrically connected to the secondary absorption module, the trip drive module comprising two thyristors connected in series, the thyristors being used to drive a tripper; A DC high-voltage voltage reduction module, which is electrically connected with the tripping drive module, and includes a voltage reduction resistor, a field effect transistor and a first transient voltage suppressor connected with each other, and is capable of converting high-voltage DC power into lower-voltage DC power; A power supply ripple absorption module, which is electrically connected with the DC high-voltage voltage reduction module, and includes a second transient voltage suppressor and a third transient voltage suppressor connected with each other in series, and is used for absorbing transient voltage; An electric energy storage module, which is connected in series with the DC high-voltage voltage reduction module, and is connected in parallel with the power supply ripple absorption module, and includes a first electrolytic capacitor and a second electrolytic capacitor connected with each other in series, and is capable of storing pulsating voltage.

6. The circuit module for a three-phase, four-wire ground fault circuit interrupter of claim 5, wherein, The DC high-voltage voltage reduction module includes the at least one resistor, the field effect transistor and a fourth transient voltage suppressor; Part of the resistors are between the fourth transient voltage suppressor and a gate of the field effect transistor.

7. The circuit module for a three-phase, four-wire ground fault circuit interrupter of claim 5, wherein, The circuit module further includes a detection module, which is indirectly electrically connected with the electric energy storage module, and is assembled on a circuit board, or is part of a current transformer.

8. An arc fault circuit interrupter, comprising: The circuit module includes at least part of the circuit module for a three-phase four-wire residual-current circuit breaker according to any one of claims 1 to 7.

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