Signal processing circuit of circuit breaker and circuit breaker

Abstract

The utility model provides a circuit breaker signal processing circuit and a circuit breaker, the circuit comprises a metering module and a protection module, the metering module comprises a first signal processing unit, a metering unit and a metering data processing unit, and the protection module comprises a second signal processing unit, a protection data processing unit and a tripping unit; the input end of the first signal processing unit is connected with a wiring terminal of the air-core mutual inductor, the output end is connected with the input end of the metering unit, and the output end of the metering unit is connected with the input end of the metering data processing unit; the first signal processing unit performs amplitude limiting processing on the voltage signal; the input end of the second signal processing unit is connected with the wiring terminal of the air-core mutual inductor, and the output end is connected with the input end of the protection data processing unit; and the second signal processing unit performs multiple amplitude transformation on the voltage signal to obtain a large-current voltage signal and a small-current voltage signal and inputs the signals to the protection data processing unit for protection processing, so that the metering precision and the protection performance of the circuit breaker are improved.

Description

Technical Field

[0001] The present application relates to the technical field of low-voltage electrical appliances, and in particular to a signal processing circuit for a circuit breaker and a circuit breaker. Background Art

[0002] The core function of a circuit breaker is to protect the power distribution network by collecting voltage and current. In the field of power Internet of Things, the requirements for metering accuracy and protection performance reliability are becoming increasingly higher.

[0003] At present, the air-core transformer in the circuit breaker has the advantages of large range and good linearity. However, the air-core transformer is affected by the large range and has the disadvantage of low accuracy, resulting in poor overall accuracy of the circuit breaker and inability to achieve high-precision measurement. Utility Model Content

[0004] The purpose of this application is to provide a signal processing circuit and a circuit breaker for a circuit breaker in order to address the above-mentioned deficiencies in the prior art and solve the problem that the overall accuracy of the circuit breaker in the prior art is poor and cannot meet the actual needs of high-precision measurement.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0006] In a first aspect, an embodiment of the present application provides a signal processing circuit for a circuit breaker, the circuit comprising: a metering module and a protection module, the metering module comprising: a first signal processing unit, a metering unit, and a metering data processing unit, the protection module comprising: a second signal processing unit, a protection data processing unit, and a tripping unit;

[0007] The input end of the first signal processing unit is used to connect to the terminal of the air-core transformer, the output end of the first signal processing unit is connected to the input end of the metering unit, and the output end of the metering unit is connected to the input end of the metering data processing unit; the first signal processing unit is used to limit the voltage signal of the current from the air-core transformer and send the voltage signal after the limit processing to the metering unit for measurement;

[0008] The input end of the second signal processing unit is used to connect to the terminal of the hollow core transformer, the output end of the second signal processing unit is connected to the input end of the protection data processing unit, and the output end of the protection data processing unit is connected to the input end of the tripping unit; the second signal processing unit is used to perform multiple amplitude conversions on the voltage signal of the current from the hollow core transformer to obtain a large current voltage signal and a small current voltage signal, and input the large current voltage signal and the small current voltage signal into the protection data processing unit for protection processing, wherein the voltage of the large current voltage signal is smaller than the voltage signal of the current of the hollow core transformer, and the voltage of the small current voltage signal is greater than the voltage signal of the current of the hollow core transformer.

[0009] As an optional implementation, the first signal processing unit includes: a first metering clipping unit, a second metering clipping unit, a third metering clipping unit, and a fourth metering clipping unit;

[0010] The input end of the first measurement and limiting unit is connected to the voltage signal of the first live wire current of the terminal of the air-core transformer, the first output end of the first measurement and limiting unit is connected to the input end of the metering unit, and the second output end of the first measurement and limiting unit is grounded;

[0011] The input end of the second measurement and limiting unit is connected to the voltage signal of the second live wire current of the terminal of the air-core transformer, the first output end of the second measurement and limiting unit is connected to the input end of the metering unit, and the second output end of the second measurement and limiting unit is grounded;

[0012] The input end of the third measurement and limiting unit is connected to the voltage signal of the third live wire current of the terminal of the air-core transformer, the first output end of the third measurement and limiting unit is connected to the input end of the metering unit, and the second output end of the third measurement and limiting unit is grounded;

[0013] The input end of the fourth metering limiter unit is connected to the voltage signal of the neutral current of the terminal of the air-core transformer, the first output end of the fourth metering limiter unit is connected to the input end of the metering unit, and the second output end of the fourth metering limiter unit is grounded.

[0014] As an optional implementation, the first metering limiter unit includes: a first resistor, a second resistor, a first bidirectional diode, and a first capacitor;

[0015] One end of the first resistor is connected to the voltage signal of the first live wire current of the connection terminal of the air-core transformer, and the other end of the first resistor is connected to one end of the second resistor and one end of the first bidirectional diode;

[0016] The other end of the second resistor is connected to one end of the first capacitor and the input end of the metering unit;

[0017] The other end of the first bidirectional diode and the other end of the first capacitor are grounded.

[0018] As an optional implementation, the second signal processing unit includes: a first processing unit, a second processing unit, a third processing unit, and a fourth processing unit;

[0019] The input end of the first processing unit is connected to the voltage signal of the first live wire current of the terminal of the air-core transformer, the first output end and the second output end of the first processing unit are both connected to the input end of the protection data processing unit, the first output end of the first processing unit is used to output a first large current voltage signal, and the second output end of the first processing unit is used to output a first small current voltage signal;

[0020] The input end of the second processing unit is connected to the voltage signal of the second live wire current of the terminal of the air-core transformer, the first output end and the second output end of the second processing unit are both connected to the input end of the protection data processing unit, the first output end of the second processing unit is used to output the second large current voltage signal, and the second output end of the second processing unit is used to output the second small current voltage signal;

[0021] The input end of the third processing unit is connected to the voltage signal of the third live wire current of the terminal of the air-core transformer, the first output end and the second output end of the third processing unit are both connected to the input end of the protection data processing unit, the first output end of the third processing unit is used to output the third large current voltage signal, and the second output end of the third processing unit is used to output the third small current voltage signal;

[0022] The input end of the fourth processing unit is connected to the voltage signal of the neutral current of the terminal of the air-core transformer, the first output end and the second output end of the fourth processing unit are both connected to the input end of the protection data processing unit, the first output end of the fourth processing unit is used to output a fourth large current voltage signal, and the second output end of the fourth processing unit is used to output a fourth small current voltage signal.

[0023] As an optional implementation, the first processing unit includes: a first protection limiting unit, a first large current protection unit, and a first small current protection unit;

[0024] The input end of the first protection limiter unit is connected to the voltage signal of the first live wire current of the connection terminal of the air-core transformer, and the output end of the first protection limiter unit is connected to the first input end of the first protection high current unit;

[0025] The second input terminal of the first large current protection unit is connected to the reference voltage, the first output terminal of the first large current protection unit is connected to the first input terminal of the first small current protection unit, and the second output terminal of the first large current protection unit is connected to the input terminal of the protection data processing unit;

[0026] The second input terminal of the first protection low current unit is connected to the reference voltage, and the output terminal of the first protection low current unit is connected to the input terminal of the protection data processing unit.

[0027] As an optional implementation, the first protection limiting unit includes: a third resistor, a first operational amplifier, and a fourth resistor;

[0028] One end of the third resistor is connected to the voltage signal of the first live wire current of the connection terminal of the air-core transformer, and the other end of the third resistor is connected to one end of the fourth resistor and the first input end of the first operational amplifier;

[0029] The second input terminal of the first operational amplifier is grounded, and the output terminal of the first operational amplifier is connected to the other end of the fourth resistor and the first input terminal of the first high-current protection unit.

[0030] As an optional implementation, the first high-current protection unit includes: a fifth resistor, a sixth resistor, a second operational amplifier, a seventh resistor, an eighth resistor, a ninth resistor, and a second capacitor;

[0031] One end of the fifth resistor is connected to the output end of the first protection limiter unit, and the other end of the fifth resistor is connected to one end of the sixth resistor and the first input end of the second operational amplifier;

[0032] The other end of the sixth resistor is connected to the output end of the second operational amplifier, one end of the ninth resistor and the first input end of the first protection low current unit;

[0033] One end of the seventh resistor is connected to the reference voltage, and the other end of the seventh resistor is connected to one end of the eighth resistor and the second input end of the second operational amplifier;

[0034] The other end of the eighth resistor is grounded;

[0035] The other end of the ninth resistor is connected to one end of the second capacitor and the input end of the protection data processing unit;

[0036] The other end of the second capacitor is grounded.

[0037] As an optional implementation, the first low-current protection unit includes: a tenth resistor, an eleventh resistor, a third operational amplifier, a twelfth resistor, a thirteenth resistor, and a third capacitor;

[0038] One end of the tenth resistor is connected to the first output end of the first high-current protection unit, and the other end of the tenth resistor is connected to one end of the eleventh resistor and the first input end of the third operational amplifier;

[0039] The other end of the tenth resistor is connected to the output end of the third operational amplifier and one end of the thirteenth resistor;

[0040] One end of the twelfth resistor is connected to the reference voltage, and the other end of the twelfth resistor is connected to the second input end of the third operational amplifier;

[0041] The other end of the thirteenth resistor is connected to one end of the third capacitor and the input end of the protection data processing unit;

[0042] The other end of the third capacitor is grounded.

[0043] As an optional implementation, the circuit further includes: a display control unit, a display unit, and a communication unit;

[0044] The display control unit is connected to the display unit;

[0045] The metering data processing unit, the display control unit and the protection data processing unit are connected to one end of the communication unit via a controller area network bus, and the other end of the communication unit is connected to an external device.

[0046] In a second aspect, an embodiment of the present application provides a circuit breaker, comprising the signal processing circuit, the air-core mutual inductor, and the circuit breaker body of the circuit breaker described in the first aspect.

[0047] The beneficial effects of this application are:

[0048] The present application provides a signal processing circuit for a circuit breaker and a circuit breaker. A metering module and a protection module are provided in the signal processing circuit of the circuit breaker. The first signal processing unit in the metering module performs amplitude limiting processing on the voltage signals of each phase current of the connected air-core transformer, and isolates the voltage signals of each phase current of the air-core transformer from each other to avoid crosstalk between the voltage signals of each phase current. The first signal processing unit sends the voltage signals after amplitude limiting processing to the metering unit in the metering module, which samples the voltage signals after amplitude limiting processing to obtain metering data. The metering unit sends the metering data to the metering data processing unit in the metering module for metering data processing, thereby achieving high-precision metering of the circuit breaker. The second signal processing unit in the protection module performs scaling processing, differential processing, and amplification processing on the voltage signals of each phase current of the connected air-core transformer using a multi-stage operational amplifier, respectively reducing and amplifying the amplitude of the voltage signal. By performing multiple amplitude conversions on the voltage signals of each phase current of the air-core transformer, a large current voltage signal of each phase and a small current voltage signal of each phase are obtained. The second signal processing unit sends the high-current voltage signal and the low-current voltage signal for each phase to the protection data processing unit in the protection module. The protection data processing unit then determines whether the circuit is experiencing an overvoltage or undervoltage fault based on these signals. Because the voltage of each high-current voltage signal is lower than the corresponding voltage signal for each phase current, the circuit breaker's measuring range is increased. The voltage of each low-current voltage signal is higher than the corresponding voltage signal for each phase current, facilitating more accurate voltage sampling by the protection data processing unit, thereby improving the circuit breaker's protective performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 A schematic diagram of an air-core transformer and its connection terminals provided in an embodiment of the present application;

[0051] Figure 2 A schematic diagram of the structure of a signal processing circuit of a circuit breaker provided in an embodiment of the present application;

[0052] Figure 3 A schematic structural diagram of a first signal processing unit and a second signal processing unit of a signal processing circuit of a circuit breaker provided in an embodiment of the present application;

[0053] Figure 4A schematic structural diagram of a first metering and limiting unit of a first signal processing unit of a signal processing circuit of a circuit breaker provided in an embodiment of the present application;

[0054] Figure 5 A schematic structural diagram of a first processing unit of a second signal processing unit of a signal processing circuit of a circuit breaker provided in an embodiment of the present application;

[0055] Figure 6 A schematic structural diagram of a first protection limiting unit of a first processing unit of a second signal processing unit of a signal processing circuit of a circuit breaker provided in an embodiment of the present application;

[0056] Figure 7 A schematic structural diagram of a first high-current protection unit of a first processing unit of a second signal processing unit of a signal processing circuit of a circuit breaker provided in an embodiment of the present application;

[0057] Figure 8 A schematic structural diagram of a first low-current protection unit of a first processing unit of a second signal processing unit of a signal processing circuit of a circuit breaker provided in an embodiment of the present application;

[0058] Figure 9 Another structural schematic diagram of the signal processing circuit of the circuit breaker provided in an embodiment of the present application;

[0059] Figure 10 This is another structural schematic diagram of the signal processing circuit of the circuit breaker provided in an embodiment of the present application.

[0060] Icon: Metering module: 1; Protection module: 2; Power supply module: 3; First signal processing unit: 11; Metering unit: 12; Metering data processing unit: 13; Display control unit: 14; Display unit: 15; Communication unit 16; Second signal processing unit: 21; Protection data processing unit: 22; Trip unit: 23; First metering limiter unit: 111; Second metering limiter unit: 112; Third metering limiter unit: 113; Fourth metering limiter unit: 114; First processing unit: 211; Second processing unit: 212; Third processing unit: 213; Fourth processing unit: 214; First protection limiter unit: 2111; First high current protection unit: 2112; First low current protection unit: 2113; First resistor: R1; Second resistor: R2; Third resistor: R3; Fourth resistor: R4; Fifth resistor: R5; Sixth resistor: R6; Seventh resistor: R7; Eighth resistor: R8; Ninth resistor: R9; Tenth resistor: R 10 ; Eleventh resistor: R 11 ; 12th resistor: R 12 ; Thirteenth resistor: R 13; First bidirectional diode: D1; First capacitor: C1; Second capacitor: C2; Third capacitor: C3; First operational amplifier: U1; Second operational amplifier: U2; Third operational amplifier: U3. DETAILED DESCRIPTION

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0062] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0063] It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. In the description of this application, the terms "first," "second," "third," etc. are used only to distinguish the description and are not to be understood as indicating or implying relative importance.

[0064] In the description of this application, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0065] In the field of the power Internet of Things, the requirements for the measurement accuracy and protection reliability of circuit breakers are becoming increasingly stringent. Currently, the air-core transformers in circuit breakers are limited by their large range, resulting in poor overall accuracy and the inability to achieve high-precision measurement, which has certain limitations.

[0066] Based on the above-mentioned problems, an embodiment of the present application provides a signal processing circuit for a circuit breaker, comprising a metering module and a protection module. The metering module comprises a first signal processing unit, a metering unit, a metering data processing unit, a display control unit, a display unit, and a communication unit. The protection module comprises a second signal processing unit, a protection data processing unit, and a tripping unit. Each metering limiter in the first signal processing unit of the metering module performs limiter processing on the voltage signal of each phase current of the air-core transformer, so that the metering unit performs high-precision sampling based on the voltage signal after limiter processing, thereby improving the measurement accuracy of the circuit breaker. Each processing unit in the second signal processing unit of the protection module performs multiple amplitude conversions on the voltage signal of each phase current of the air-core transformer, including scaling and isolating the voltage signal by the protection limiter in the processing unit, differential processing of the voltage signal by the protection high-current unit, and amplification of the voltage signal by the protection low-current unit, thereby obtaining a high-current voltage signal of each phase and a low-current voltage signal of each phase, respectively, so that the protection data processing unit performs protection processing on the circuit based on the high-current voltage signal of each phase and the low-current voltage signal of each phase, thereby increasing the measurement range of the circuit breaker and improving the measurement accuracy of the circuit breaker.

[0067] Figure 1 A schematic diagram of the hollow core transformer and the connection terminals of the hollow core transformer provided in the embodiment of the present application is shown as follows: Figure 1 As shown, the air-core transformer in the circuit breaker provides the circuit with voltage signals of each phase current, including the voltage signal I of the first live wire A phase current. A , the voltage signal I of the second live wire B phase current B , the voltage signal I of the third live wire C phase current C And the voltage signal I of the neutral line N phase current N Each phase air-core transformer has two output terminals. One terminal of each phase air-core transformer is connected to the common terminal GND of the air-core transformer terminal for easy wiring. The other terminal of each phase air-core transformer is connected to the input terminals of the air-core transformer terminal. The air-core transformer A phase converts the voltage signal I of the first live wire current into A The first input terminal of the air-core transformer is sent to the first input terminal of the air-core transformer, and the air-core transformer B phase converts the voltage signal I B The air-core transformer C phase sends the voltage signal I C The third input terminal of the air-core transformer is sent to the terminal of the air-core transformer. The N phase of the air-core transformer converts the voltage signal of the neutral current I N The fourth input terminal is sent to the terminal block of the air core transformer.

[0068] Figure 2 A schematic diagram of the structure of the signal processing circuit of the circuit breaker provided in the embodiment of the present application is shown as follows: Figure 2 As shown, the signal processing circuit of the circuit breaker includes: a metering module 1 and a protection module 2. The metering module 1 includes: a first signal processing unit 11, a metering unit 12 and a metering data processing unit 13. The protection module 2 includes a second signal processing unit 21, a protection data processing unit 22 and a tripping unit 23.

[0069] Optionally, refer to Figure 2 The circuit breaker's signal processing circuit includes two modules: a metering module 1 and a protection module 2. The metering module 1 includes three units: a first signal processing unit 11, a metering unit 12, and a metering data processing unit 13. The protection module 2 includes three units: a second signal processing unit 21, a protection data processing unit 22, and a tripping unit 23.

[0070] The input end of the first signal processing unit 11 is used to connect to the terminal of the air-core transformer, the output end of the first signal processing unit 11 is connected to the input end of the metering unit 12, and the output end of the metering unit 12 is connected to the input end of the metering data processing unit 13; the first signal processing unit 11 is used to limit the voltage signal of the current from the air-core transformer, and send the voltage signal after limiting processing to the metering unit 12 for metering.

[0071] Optionally, continue with reference to Figure 2 The input end of the first signal processing unit 11 in the metering module 1 is connected to the terminal of the air-core transformer to receive the voltage signal of each phase current of the air-core transformer. The first signal processing unit 11 performs a limiting process on the voltage signal of each phase current of the connected air-core transformer and isolates the voltage signals of each phase current of the air-core transformer from each other to avoid crosstalk between the voltage signals of each phase current. The output end of the first signal processing unit 11 is connected to the input end of the metering unit 12 to send the voltage signals after the limiting process to the metering unit 12. The metering unit 12 samples the voltage signals after the limiting process to obtain metering data. The output end of the metering unit 12 is connected to the input end of the metering data processing unit 13 to send the metering data to the metering data processing unit 13 for metering data processing, thereby achieving high-precision metering of the circuit breaker.

[0072] The input end of the second signal processing unit 21 is used to connect to the terminal of the air-core transformer, the output end of the second signal processing unit 21 is connected to the input end of the protection data processing unit 22, and the first output end of the protection data processing unit 22 is connected to the input end of the tripping unit 23; the second signal processing unit 21 is used to perform multiple amplitude conversions on the voltage signal of the current from the air-core transformer to obtain a large current voltage signal and a small current voltage signal, and input the large current voltage signal and the small current voltage signal into the protection data processing unit 22 for protection processing, wherein the voltage of the large current voltage signal is less than the voltage signal of the current of the air-core transformer, and the voltage of the small current voltage signal is greater than the voltage signal of the current of the air-core transformer.

[0073] Optionally, continue with reference to Figure 2 The input end of the second signal processing unit 21 in the protection module 2 is connected to the terminal of the air-core transformer to receive the voltage signal I of the first live wire A phase current of the air-core transformer. A , the voltage signal I of the second live wire B phase current B , the voltage signal I of the third live wire C phase current C and the voltage signal I of the neutral line N phase current N The second signal processing unit 21 uses a multi-stage operational amplifier to perform scaling processing, differential processing, and amplification processing on the voltage signal of each phase current of the connected air-core transformer, respectively reducing and amplifying the amplitude of the voltage signal, and obtaining the large current voltage signal of each phase and the small current voltage signal of each phase through multiple amplitude conversions. Among them, the voltage of the large current voltage signal of each phase is smaller than the voltage signal of the corresponding phase current, which can increase the range of the circuit breaker; the voltage of the small current voltage signal of each phase is larger than the voltage signal of the corresponding phase current, which has higher accuracy and can improve the protection performance of the circuit breaker.

[0074] Optionally, the output end of the second signal processing unit 21 is connected to the input end of the protection data processing unit 22, and the output end of the protection data processing unit 22 is connected to the input end of the tripping unit 23. The second signal processing unit 21 sends the large current and voltage signals of each phase and the small current and voltage signals of each phase to the protection data processing unit 22, so that the protection data processing unit 22 can accurately judge the overvoltage fault and undervoltage fault of the circuit within a large range according to the large current and voltage signals of each phase and the small current and voltage signals of each phase. When an overvoltage fault or undervoltage fault occurs in the circuit, the protection data processing unit 22 generates a tripping instruction and sends the tripping instruction to the tripping unit 23, so that the magnetic flux tripper ( Figure 2 The circuit is tripped under the instruction of the tripping instruction (not shown), and the circuit is cut off to achieve over-voltage and under-voltage protection.

[0075] In this embodiment, a metering module and a protection module are provided in the signal processing circuit of the circuit breaker. The first signal processing unit in the metering module performs amplitude limiting processing on the voltage signals of each phase current of the connected air-core transformer and isolates the voltage signals of each phase current of the air-core transformer from each other to avoid crosstalk between the voltage signals of each phase current. The first signal processing unit sends each voltage signal after amplitude limiting processing to the metering unit in the metering module, which samples each voltage signal after amplitude limiting processing to obtain metering data. The metering unit sends the metering data to the metering data processing unit in the metering module for metering data processing, thereby achieving high-precision metering of the circuit breaker. The second signal processing unit in the protection module uses a multi-stage operational amplifier to perform scaling, differential processing, and amplification processing on the voltage signals of each phase current of the connected air-core transformer, respectively reducing and amplifying the amplitude of the voltage signal. By performing multiple amplitude conversions on the voltage signals of each phase current of the air-core transformer, a large current voltage signal and a small current voltage signal of each phase are obtained. The second signal processing unit sends the high-current voltage signal and the low-current voltage signal for each phase to the protection data processing unit in the protection module. The protection data processing unit then determines whether the circuit is experiencing an overvoltage or undervoltage fault based on these signals. Because the voltage of each high-current voltage signal is lower than the corresponding voltage signal for each phase current, the circuit breaker's measuring range is increased. The voltage of each low-current voltage signal is higher than the corresponding voltage signal for each phase current, facilitating more accurate voltage sampling by the protection data processing unit, thereby improving the circuit breaker's protective performance.

[0076] Figure 3 A schematic structural diagram of a first signal processing unit and a second signal processing unit of a signal processing circuit of a circuit breaker provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the first signal processing unit 11 includes: a first metering and clipping unit 111 , a second metering and clipping unit 112 , a third metering and clipping unit 113 and a fourth metering and clipping unit 114 .

[0077] Optionally, refer to Figure 3 The first signal processing unit 11 includes four measurement limiter units, namely the first measurement limiter unit 111, the second measurement limiter unit 112, the third measurement limiter unit 113 and the fourth measurement limiter unit 114. The first measurement limiter unit 111 is used to process the voltage signal I of the first live wire A phase current of the terminal of the air-core transformer. A Perform measurement limiting processing to obtain the voltage signal MI of the first live wire A phase current after limiting processing A Accordingly, the second measurement limiter unit 112 is used to measure the voltage signal I of the second live wire B phase current of the air-core transformer terminal. BPerform measurement limiting processing to obtain the voltage signal MI of the second live wire B phase current after limiting processing B The third measurement and limiting unit 113 is used to measure the voltage signal I of the third live wire C phase current of the air-core transformer terminal. C Perform measurement limiting processing to obtain the voltage signal MI of the third live wire C phase current after limiting processing C The fourth measurement and limiting unit 114 is used to measure the voltage signal I of the neutral line N-phase current of the air-core transformer terminal. N Perform amplitude limiting processing to obtain the voltage signal MI of the second live wire N phase current after amplitude limiting processing N .

[0078] The input end of the first measurement and limiting unit 111 is connected to the voltage signal I of the first live wire current of the terminal of the air-core transformer. A The first output end of the first metering limiter unit 111 is connected to the input end of the metering unit 12, and the second output end of the first metering limiter unit 111 is grounded.

[0079] Optionally, continue with reference to Figure 3 The first measurement limiter unit 111 includes an input terminal and two output terminals, wherein the input terminal of the first measurement limiter unit 111 is connected to the voltage signal I of the first live wire A phase current of the terminal of the air core transformer. A The second output terminal of the first measurement and limiting unit 111 is grounded. The first measurement and limiting unit 111 is connected to the voltage signal I A Perform amplitude limiting processing to change the voltage signal I A The voltage of the first live wire current is limited to between plus and minus 0.7V, and the voltage signal I A The voltage signal I of the second live wire B phase current B , the voltage signal I of the third live wire C phase current C And the voltage signal I of the neutral line N phase current N Isolation prevents crosstalk between signals and obtains the voltage signal MI of the first live wire A phase current after amplitude limiting processing A The first output terminal of the first measurement and limiting unit 111 is connected to the input terminal of the measurement unit 12 to convert the voltage signal MI of the first live wire A phase current after the limiting process into the voltage signal MI A Sent to the metering unit 12.

[0080] The input end of the second measurement and limiting unit 112 is connected to the voltage signal I of the second live wire current of the terminal of the air-core transformer. B The first output end of the second metering limiter unit 112 is connected to the input end of the metering unit 12, and the second output end of the second metering limiter unit 112 is grounded.

[0081] Optionally, continue with reference to Figure 3 The second measurement limiter unit 112 includes an input terminal and two output terminals, wherein the input terminal of the second measurement limiter unit 112 is connected to the voltage signal I of the second live wire B phase current of the terminal of the air-core transformer. B The second output terminal of the second measurement and amplitude limiting unit 112 is grounded. The second measurement and amplitude limiting unit 112 is connected to the voltage signal I B Perform amplitude limiting processing to reduce the voltage signal I B The voltage of the second live wire B phase current is limited to between plus and minus 0.7V, and the voltage signal I B The voltage signal I of the first live wire current A , the voltage signal I of the third live wire C phase current C And the voltage signal I of the neutral line N phase current N Isolation prevents crosstalk between signals and obtains the voltage signal MI of the second live wire B phase current after amplitude limiting. B The first output terminal of the second measurement and limiting unit 112 is connected to the input terminal of the measurement unit 12 to convert the voltage signal MI of the second live wire B phase current after the limiting process into the voltage signal MI B Sent to the metering unit 12.

[0082] The input end of the third metering and limiting unit 113 is connected to the voltage signal I of the third live wire current of the terminal of the air-core transformer. C The first output end of the third metering limiter unit 113 is connected to the input end of the metering unit 12, and the second output end of the third metering limiter unit 113 is grounded.

[0083] Optionally, continue with reference to Figure 3 The third measurement limiter unit 113 includes an input terminal and two output terminals, wherein the input terminal of the third measurement limiter unit 113 is connected to the voltage signal I of the third live wire C phase current of the terminal of the air-core transformer. C The third measuring and limiting unit 113 is connected to the ground. The third measuring and limiting unit 113 is connected to the voltage signal I C Perform amplitude limiting processing to reduce the voltage signal I C The voltage of the third live wire C phase current is limited to between plus and minus 0.7V, and the voltage signal I C The voltage signal I of the first live wire current A , the voltage signal I of the second live wire B phase current B And the voltage signal I of the neutral line N phase current N Isolation prevents crosstalk between signals and obtains the voltage signal MI of the third live wire C phase current after amplitude limiting. CThe first output terminal of the third measurement and limiting unit 113 is connected to the input terminal of the measurement unit 12 to convert the voltage signal MI of the third live wire C phase current after the limiting process into the voltage signal MI C Sent to the metering unit 12.

[0084] The input end of the fourth measurement and limiting unit 114 is connected to the voltage signal I of the neutral current of the air-core transformer terminal. N The first output end of the fourth metering limiter unit 114 is connected to the input end of the metering unit 12, and the second output end of the fourth metering limiter unit 114 is grounded.

[0085] Optionally, continue with reference to Figure 3 The fourth measurement limiter unit 114 includes an input terminal and two output terminals, wherein the input terminal of the fourth measurement limiter unit 114 is connected to the voltage signal I of the neutral line N phase current of the terminal of the air core transformer. N , the second output terminal of the fourth measurement and limiting unit 114 is grounded. The fourth measurement and limiting unit 114 is connected to the voltage signal I of the neutral line N phase current. N Perform amplitude limiting processing to make the voltage signal I N The voltage of the neutral line N phase current is limited to between plus and minus 0.7V, and the voltage signal I N The voltage signal I of the first live wire current A , the voltage signal I of the second live wire B phase current B And the voltage signal I of the third live wire C phase current C Isolation prevents crosstalk between signals and obtains the voltage signal MI of the neutral line N phase current after amplitude limiting. N The first output terminal of the fourth measurement and limiting unit 114 is connected to the input terminal of the measurement unit 12 to convert the voltage signal MI of the zero line N phase current after the limiting process into the voltage signal MI N Sent to the metering unit 12.

[0086] In this embodiment, a first metering limiter unit, a second metering limiter unit, a third metering limiter unit, and a fourth metering limiter unit are provided in the first signal processing unit. Each metering limiter unit performs limit processing on the voltage signal of each phase current at the terminal of the connected air-core transformer, thereby obtaining a voltage signal of each phase current after limit processing. This isolates the voltage signals of each phase current from each other to avoid signal crosstalk. Each metering limiter unit transmits the voltage signal of each phase current after limit processing to the metering unit, so that the metering unit performs voltage sampling based on the voltage signal of each phase current after limit processing transmitted by each metering limiter unit to obtain metering data.

[0087] Figure 4 This is a structural diagram of the first metering limiter unit of the first signal processing unit of the signal processing circuit of the circuit breaker provided in an embodiment of the present application, as shown in FIG. Figure 4 As shown, the first measurement and limiting unit 111 includes: a first resistor R1, a second resistor R2, a first bidirectional diode D1 and a first capacitor C1.

[0088] Optionally, refer to Figure 4 Taking the first measurement limiter unit 111 in the first signal processing unit 11 as an example, the first measurement limiter unit 111 includes two resistors, a bidirectional diode, and a capacitor, namely, a first resistor R1, a second resistor R2, a first bidirectional diode D1, and a first capacitor C1. The first measurement limiter unit 111 processes the voltage signal I of the first live wire A phase current of the air-core transformer terminal through the first resistor R1, the second resistor R2, the first bidirectional diode D1, and the first capacitor C1. A Perform amplitude limiting processing to obtain the voltage signal MI of the first live wire A phase current after amplitude limiting processing A The first resistor R1 isolates the voltage signal I of the first live wire current by means of resistance isolation. A The voltage signal I of the second live wire B phase current B , the voltage signal I of the third live wire C phase current C And the voltage signal I of the neutral line N phase current N , to avoid signal crosstalk. The first bidirectional diode D1 plays a limiting role, limiting the voltage signal I A The voltage is limited to between plus and minus 0.7V, and the second resistor R2 and the first capacitor C1 play a filtering role.

[0089] One end of the first resistor R1 is connected to the first live wire current voltage signal I of the connection terminal of the air-core transformer A The other end of the first resistor R1 is connected to one end of the second resistor R2 and one end of the first bidirectional diode D1.

[0090] Optionally, continue with reference to Figure 4 One end of the first resistor R1 is used as the input end of the first signal processing unit 11 and the input end of the first measurement limiter unit, and is connected to the voltage signal I of the first live wire A phase current of the air core transformer terminal. A The other end of the first resistor R1 is connected to one end of the second resistor R2 and one end of the first bidirectional diode D1.

[0091] The other end of the second resistor R2 is connected to one end of the first capacitor C1 and the input end of the metering unit 12 .

[0092] Optionally, continue with reference to Figure 4 The other end of the second resistor R2 is connected to one end of the first capacitor C1 and the input end of the metering unit 12 to convert the voltage signal MI of the first live wire A phase current after the amplitude limiting process into A Sent to the metering unit 12.

[0093] The other end of the first bidirectional diode D1 and the other end of the first capacitor C1 are grounded.

[0094] Optionally, continue with reference to Figure 4 The other end of the first bidirectional diode D1 and the other end of the first capacitor C1 are both grounded as the second output end of the first measurement limiter unit.

[0095] In this embodiment, the first resistor in the first metering limiting unit isolates the voltage signal of the first live wire current from the voltage signal of the second live wire B phase current, the voltage signal of the third live wire C phase current, and the voltage signal of the neutral wire N phase current through resistance isolation, thereby avoiding signal crosstalk. The first bidirectional diode in the first metering limiting unit acts as a limiter, limiting the voltage of the voltage signal of the first live wire current to between positive and negative 0.7V. The second resistor and the first capacitor in the first metering limiting unit act as filters. The first metering limiting unit performs a limiting process on the voltage signal of the first live wire A phase current of the terminal of the air-core transformer through the first resistor, the second resistor, the first bidirectional diode, and the first capacitor, thereby improving the quality of the voltage signal of the first live wire A phase current after the limiting process, thereby improving the metering accuracy.

[0096] As an optional implementation, the second signal processing unit 21 includes: a first processing unit 211 , a second processing unit 212 , a third processing unit 213 and a fourth processing unit 214 .

[0097] Optionally, continue with reference to Figure 3 The second signal processing unit 21 includes four processing units, namely a first processing unit 211, a second processing unit 212, a third processing unit 213 and a fourth processing unit 214. The first processing unit 211 is used to process the voltage signal I of the first live wire A phase current of the terminal of the air-core transformer. A Perform scaling, differential processing, and amplification processing to reduce and amplify the amplitude of the voltage signal, respectively, to obtain the first large current voltage signal I A H and the first small current voltage signal I A L. Accordingly, the second processing unit 212 is used to process the voltage signal I of the second live wire B phase current of the terminal of the air-core transformer. B Perform scaling, differential processing, and amplification processing to reduce and amplify the amplitude of the voltage signal, respectively, to obtain the second largest current voltage signal I B H and the second smallest current voltage signal I B The third processing unit 213 is used to process the voltage signal I of the third live wire C phase current of the terminal of the air-core transformer CPerform scaling, differential processing, and amplification processing to reduce and amplify the amplitude of the voltage signal, respectively, to obtain the third largest current voltage signal I C H and the third smallest current voltage signal I C The fourth processing unit 214 is used to process the voltage signal I of the neutral line N-phase current of the terminal of the air-core transformer. N Perform scaling, differential processing, and amplification processing to reduce and amplify the amplitude of the voltage signal, respectively, to obtain the fourth largest current voltage signal I N H and the fourth smallest current voltage signal I N L.

[0098] The input end of the first processing unit 211 is connected to the voltage signal I of the first live wire current of the terminal of the air-core transformer. A The first output terminal and the second output terminal of the first processing unit 211 are both connected to the input terminal of the protection data processing unit 22. The first output terminal of the first processing unit 211 is used to output the first large current voltage signal I A H, the second output terminal of the first processing unit 211 is used to output the first small current voltage signal I A L.

[0099] Optionally, continue with reference to Figure 3 The first processing unit 211 includes an input terminal and two output terminals, wherein the input terminal of the first processing unit 211 is connected to the voltage signal I of the first live wire A phase current of the terminal of the air-core transformer. A The first processing unit 211 processes the voltage signal I of the first live wire A phase current through a multi-stage operational amplifier. A Perform scaling, differential processing, and amplification processing to reduce and amplify the amplitude of the voltage signal, respectively, to obtain the first large current voltage signal I A H and the first small current voltage signal I A The first output terminal of the first processing unit 211 and the second output terminal of the first processing unit 211 are both connected to the input terminal of the protection data processing unit 22, so as to send the first large current voltage signal I to the protection data processing unit 22 through the first output terminal of the first processing unit 211. A H, sends the first low current voltage signal I to the protection data processing unit 22 through the second output terminal of the first processing unit 211 A L.

[0100] The input end of the second processing unit 212 is connected to the voltage signal I of the second live wire current of the terminal of the air-core transformer. B The first output terminal and the second output terminal of the second processing unit 212 are both connected to the input terminal of the protection data processing unit 22, and the first output terminal of the second processing unit 212 is used to output the second large current voltage signal IB H, the second output terminal of the second processing unit 212 is used to output a second small current voltage signal I B L.

[0101] Optionally, continue with reference to Figure 3 The second processing unit 212 includes an input terminal and two output terminals, wherein the input terminal of the second processing unit 212 is connected to the voltage signal I of the second live wire B phase current of the terminal of the air-core transformer. B The second processing unit 212 processes the voltage signal I of the second live wire B phase current through a multi-stage operational amplifier. B Perform scaling, differential processing, and amplification processing to reduce and amplify the amplitude of the voltage signal, respectively, to obtain the second largest current voltage signal I B H and the second smallest current voltage signal I B The first output terminal of the second processing unit 212 and the second output terminal of the second processing unit 212 are both connected to the input terminal of the protection data processing unit 22, so as to send the second large current voltage signal I to the protection data processing unit 22 through the first output terminal of the second processing unit 212. B H, sends a second low current voltage signal I to the protection data processing unit 22 through the second output terminal of the second processing unit 212 B L.

[0102] The input end of the third processing unit 213 is connected to the voltage signal I of the third live wire current of the connection terminal of the air-core transformer. C The first output terminal and the second output terminal of the third processing unit 213 are both connected to the input terminal of the protection data processing unit 22. The first output terminal of the third processing unit 213 is used to output the third large current and voltage signal I C H, the second output terminal of the third processing unit 213 is used to output the third small current voltage signal I C L.

[0103] Optionally, continue with reference to Figure 3 The third processing unit 213 includes an input terminal and two output terminals, wherein the input terminal of the third processing unit 213 is connected to the voltage signal I of the third live wire C phase current of the terminal of the air-core transformer. C The third processing unit 213 processes the voltage signal I of the third live wire C phase current through a multi-stage operational amplifier. C Perform scaling, differential processing, and amplification processing to reduce and amplify the amplitude of the voltage signal, respectively, to obtain the third largest current voltage signal I C H and the third smallest current voltage signal I CThe first output terminal of the third processing unit 213 and the second output terminal of the third processing unit 213 are both connected to the input terminal of the protection data processing unit 22, so as to send the third large current voltage signal I to the protection data processing unit 22 through the first output terminal of the third processing unit 213. C H, sends the third low current voltage signal I to the protection data processing unit 22 through the second output terminal of the third processing unit 213 C L.

[0104] The input end of the fourth processing unit 214 is connected to the voltage signal I of the neutral current of the terminal of the air-core transformer. N The first output terminal and the second output terminal of the fourth processing unit 214 are both connected to the input terminal of the protection data processing unit 22, and the first output terminal of the fourth processing unit 214 is used to output the fourth large current and voltage signal I N H, the second output terminal of the fourth processing unit 214 is used to output the fourth small current voltage signal I N L.

[0105] Optionally, continue with reference to Figure 3 The fourth processing unit 214 includes an input terminal and two output terminals, wherein the input terminal of the fourth processing unit 214 is connected to the voltage signal I of the neutral line N phase current of the terminal of the air core transformer. N The fourth processing unit 214 processes the voltage signal I of the neutral line N-phase current through a multi-stage operational amplifier. N Perform scaling, differential processing, and amplification processing to reduce and amplify the amplitude of the voltage signal, respectively, to obtain the fourth largest current voltage signal I N H and the fourth smallest current voltage signal I N The first output terminal of the fourth processing unit 214 and the second output terminal of the fourth processing unit 214 are both connected to the input terminal of the protection data processing unit 22, so as to send the fourth large current voltage signal I to the protection data processing unit 22 through the first output terminal of the fourth processing unit 214. N H, sends the fourth low current voltage signal I to the protection data processing unit 22 through the second output terminal of the fourth processing unit 214 N L.

[0106] In this embodiment, a first processing unit, a second processing unit, a third processing unit, and a fourth processing unit are provided within the second signal processing unit. Each processing unit performs scaling, differential processing, and amplification processing on the voltage signal of each phase current at the terminal of the connected air-core transformer to obtain a high-current voltage signal and a low-current voltage signal for each phase. Each processing unit transmits the high-current voltage signal and the low-current voltage signal for each phase to the protection data processing unit, which then performs overvoltage and undervoltage protection of the circuit based on the high-current voltage signal and the low-current voltage signal for each phase, thereby increasing the measuring range of the circuit breaker and improving protection performance.

[0107] Figure 5 A structural diagram of the first processing unit of the second signal processing unit of the signal processing circuit of the circuit breaker provided in an embodiment of the present application is shown as follows: Figure 5 As shown, the first processing unit includes 211 : a first protection limiting unit 2111 , a first protection high current unit 2112 and a first protection low current unit 2113 .

[0108] Optionally, refer to Figure 5 Taking the first processing unit 211 in the second signal processing unit 21 as an example, the first processing unit 211 includes three units, namely a first protection limiter unit 2111, a first large current protection unit 2112, and a first small current protection unit 2113. Among them, the first protection limiter unit 2111 is a first-stage operational amplifier, which is used to process the voltage signal I A Perform scaling processing to reduce the voltage signal I of the first live wire A phase current A The amplitude of the first live wire A phase current voltage signal I A Convert the voltage signal of the first live wire A phase current I into positive and negative signals. A The voltage signal I of the second live wire B phase current B , the voltage signal I of the third live wire C phase current C And the voltage signal I of the neutral line N phase current N Isolation is used to prevent crosstalk between signals, and the voltage signal I of the first live wire phase A current is obtained after scaling. A-S The first large current protection unit 2112 is a second-stage operational amplifier, which is used to scale the voltage signal I of the first live wire A phase current. A-S Perform differential processing and raise the voltage signal I of the first live wire A phase current after scaling by the reference voltage VREF A-S The level of the first large current voltage signal I A H. The first protection low current unit 2113 is a third-stage operational amplifier, used to AH is amplified and the first large current voltage signal I is raised by the reference voltage VREF. A H level, and obtain the first small current voltage signal I A L.

[0109] The input end of the first protection limiting unit 2111 is connected to the voltage signal I of the first live wire current of the terminal of the air-core transformer. A The output end of the first protection limiting unit 2111 is connected to the first input end of the first protection high current unit 2112 .

[0110] Optionally, continue with reference to Figure 5 The input end of the first protection limiter unit 2111 is used as the input end of the second signal processing unit 21 and the input end of the first processing unit 211, and is connected to the voltage signal I of the first live wire A phase current of the air core transformer terminal. A The first protection limiter unit 2111 acts as the first stage operational amplifier of the first processing unit 211, reducing the voltage signal I of the first live wire A phase current. A The amplitude of the first live wire A phase current voltage signal I A Convert to positive and negative signals and isolate the voltage signal I of the first live wire A phase current A The voltage signal I of the second live wire B phase current B , the voltage signal I of the third live wire C phase current C And the voltage signal I of the neutral line N phase current N , to prevent signal crosstalk, and obtain the voltage signal I of the first live wire A phase current after scaling processing A-S The output terminal of the first protection limiter unit 2111 is connected to the first input terminal of the first protection high current unit 2112 to convert the voltage signal I of the first live wire A phase current after scaling processing into A-S The signal is sent to the first high-current protection unit 2112 for differential processing.

[0111] The second input terminal of the first large current protection unit 2112 is connected to the reference voltage VREF, the first output terminal of the first large current protection unit 2112 is connected to the first input terminal of the first small current protection unit 2113, and the second output terminal of the first large current protection unit 2112 is connected to the input terminal of the protection data processing unit 22.

[0112] Optionally, continue with reference to Figure 5 The second input terminal of the first large current protection unit 2112 is connected to the reference voltage VREF, which is the internal reference voltage of the circuit. The first large current protection unit 2112 is the second stage operational amplifier of the first processing unit 211, which processes the voltage signal I of the first live wire A phase current after scaling. A-SPerform differential processing, and use the reference voltage VREF to scale the voltage signal I of the first live wire A phase current after scaling. A-S Raise the level to obtain the first large current and voltage signal I A H, where the first large current voltage signal I A The voltage of H is less than the voltage signal I of the first live wire A phase current A The first output terminal of the first large current protection unit 2112 is connected to the first input terminal of the first small current protection unit 2113, and the second output terminal of the first large current protection unit 2112 is connected to the input terminal of the protection data processing unit 22, so as to convert the first large current voltage signal I A H is sent to the first protection small current unit 2113 for amplification processing, and the first large current voltage signal I is converted to the first large current voltage signal I through the second output terminal of the first protection large current unit 2112. A H is sent to the protection data processing unit 22 for overvoltage and undervoltage protection of the circuit.

[0113] A second input terminal of the first protection low current unit 2113 is connected to the reference voltage VREF, and an output terminal of the first protection low current unit 2113 is connected to an input terminal of the protection data processing unit 22 .

[0114] Optionally, continue with reference to Figure 5 The second input terminal of the first protection small current unit 2113 is connected to the reference voltage VREF. The first protection small current unit 2113 serves as the third stage operational amplifier of the first processing unit 211 to process the first large current voltage signal I A H is amplified based on the reference voltage VREF. A H is level-raised to obtain the first small current voltage signal I A L, where the first small current voltage signal I A The voltage of L is greater than the voltage signal I of the first live wire A phase current A The output terminal of the first protection low current unit 2113 is connected to the input terminal of the protection data processing unit 22 to convert the first low current voltage signal I A L is sent to the protection data processing unit 22 to perform over-voltage and under-voltage protection of the circuit.

[0115] In this embodiment, a first protection limiter unit, a first protection high current unit, and a first protection low current unit are provided in the first processing unit. The first protection limiter unit serves as the first stage operational amplifier of the first processing unit to reduce the amplitude of the voltage signal of the first live wire A phase current, convert the voltage signal of the first live wire A phase current into a positive and negative signal, and convert the voltage signal I of the first live wire A phase current into a positive and negative signal. AIt is isolated from the voltage signals of the remaining phase currents to prevent crosstalk between the signals, and obtains the voltage signal of the first live wire A phase current after scaling processing. The first protection large current unit acts as a second-stage operational amplifier, and raises the level of the voltage signal of the first live wire A phase current after scaling processing through a reference voltage to obtain a first large current voltage signal. The first protection small current unit acts as a third-stage operational amplifier, and raises the level of the first large current voltage signal through a reference voltage to obtain a first small current voltage signal. Through the three-stage operational amplifier in the first processing unit, the protection data processing module is provided with large current voltage signals and small current voltage signals of each phase, thereby increasing the range of the circuit breaker and improving the protection performance of the circuit breaker.

[0116] Figure 6 A structural diagram of the first protection limiting unit of the first processing unit of the second signal processing unit of the signal processing circuit of the circuit breaker provided in an embodiment of the present application is shown as follows: Figure 6 As shown, the first protection limiter unit 2111 includes: a third resistor R3, a first operational amplifier U1 and a fourth resistor R4.

[0117] Optionally, refer to Figure 6 The first protection limiter unit 2111 includes two resistors and an operational amplifier, namely a third resistor R3, a fourth resistor R4 and a first operational amplifier U1. The first protection limiter unit 2111 reduces the voltage signal I of the first live wire A phase current through the third resistor R3, the fourth resistor R4 and the first operational amplifier U1. A The amplitude of the first live wire A phase current voltage signal I A Convert the positive and negative signals and generate the voltage signal I of the first live wire A phase current A Isolate and obtain the voltage signal I of the first live wire A phase current after scaling. A-S .

[0118] One end of the third resistor R3 is connected to the voltage signal R3 of the first live wire current of the air-core transformer terminal, and the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the first input end of the first operational amplifier U1.

[0119] Optionally, continue with reference to Figure 6 One end of the third resistor R3 is used as the input end of the first protection limiter unit 2111, the input end of the second signal processing unit 21 and the input end of the first processing unit 211, and is connected to the voltage signal I of the first live wire A phase current of the terminal of the air-core transformer. A The other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the first input end of the first operational amplifier U1 respectively.

[0120] A second input terminal of the first operational amplifier U1 is grounded, and an output terminal of the first operational amplifier is connected to the other end of the fourth resistor R4 and a first input terminal of the first high-current protection unit 2112 .

[0121] Optionally, continue with reference to Figure 6 The first operational amplifier U1 includes two input terminals, an output terminal, a positive power supply terminal, and a negative power supply terminal. The positive power supply terminal of the first operational amplifier U1 is used to connect to the positive electrode of the 2.5V power supply voltage +VCC, and the negative power supply terminal of the first operational amplifier U1 is used to connect to the negative electrode of the 2.5V power supply voltage -VCC. The second input terminal of the first operational amplifier U1 is grounded. The output terminal of the first operational amplifier is connected to the other end of the fourth resistor R4 and the first input terminal of the first protection high current unit 2112 to convert the scaled voltage signal I of the first live wire A phase current into A-S The signal is sent to the first high-current protection unit 2112 for differential processing.

[0122] In this embodiment, by setting a third resistor, a fourth resistor and a first operational amplifier in the first protection limiting unit, the amplitude of the voltage signal of the first live wire A phase current is reduced, the voltage signal of the first live wire A phase current is converted into a positive and negative signal, and the voltage signal of the first live wire A phase current is isolated to obtain the voltage signal of the first live wire A phase current after scaling processing, and the voltage signal of the first live wire A phase current after scaling processing is sent to the first protection large current unit, so that the first protection large current unit performs differential processing on the voltage signal of the first live wire A phase current after scaling processing.

[0123] Figure 7 A structural diagram of the first high current protection unit of the first processing unit of the second signal processing unit of the signal processing circuit of the circuit breaker provided in an embodiment of the present application is shown as follows: Figure 7 As shown, the first high-current protection unit 2112 includes: a fifth resistor R5, a sixth resistor R6, a second operational amplifier U2, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a second capacitor C2.

[0124] Optionally, refer to Figure 7 The first high-current protection unit 2111 includes five resistors, an operational amplifier, and a capacitor, namely, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a second operational amplifier U2, and a second capacitor C2. The first high-current protection unit 2111 processes the scaled voltage signal I of the first live wire A phase current based on the reference voltage VREF through the fifth resistor R5, the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the second operational amplifier U2, and the second capacitor C2. A-S Raise the level to obtain the first large current and voltage signal IA H.

[0125] One end of the fifth resistor R5 is connected to the output end of the first protection limiter unit 2111 , and the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6 and the first input end of the second operational amplifier U2 .

[0126] Optionally, continue with reference to Figure 7 One end of the fifth resistor R5 serves as the first input end of the first large current protection unit 2111, and is connected to the output end of the first amplitude limiting unit 2111 to receive the voltage signal I of the first live wire A phase current after scaling. A-S The other end of the fifth resistor R5 is connected to one end of the sixth resistor R6 and the first input end of the second operational amplifier U2 respectively.

[0127] The other end of the sixth resistor R6 is connected to the output end of the second operational amplifier U2 , one end of the ninth resistor R9 , and the first input end of the first protection low-current unit 2113 .

[0128] Optionally, continue with reference to Figure 7 The other end of the sixth resistor R6 is connected to the output end of the second operational amplifier U2, one end of the ninth resistor R9 and the first input end of the first protection low current unit 2113, so as to convert the first large current voltage signal I A H is sent to the first protection low current unit 2113 for amplification.

[0129] One end of the seventh resistor R7 is connected to the reference voltage VREF, the other end of the seventh resistor R7 is connected to one end of the eighth resistor R8 and the second input end of the second operational amplifier U2, and the other end of the eighth resistor U2 is grounded.

[0130] Optionally, continue with reference to Figure 7 One end of the seventh resistor R7 serves as the second input of the first high-current protection unit 2111 and is connected to the reference voltage VREF. The second operational amplifier U2 includes two input terminals, an output terminal, a positive power supply terminal, and a negative power supply terminal. The positive power supply terminal of the second operational amplifier U2 is used to connect to the positive electrode of the 3.3V power supply voltage +VDD, and the negative power supply terminal of the second operational amplifier U2 is grounded. The second input terminal of the second operational amplifier U2 is respectively connected to the other end of the seventh resistor R7 and one end of the eighth resistor R8, and the other end of the eighth resistor U2 is grounded.

[0131] The other end of the ninth resistor R9 is connected to one end of the second capacitor C2 and the input end of the protection data processing unit 22 , and the other end of the second capacitor C2 is grounded.

[0132] Optionally, continue with reference to Figure 7The other end of the ninth resistor R9 is connected to one end of the second capacitor C2 and the input end of the protection data processing unit 22, so as to convert the first large current voltage signal I A H is sent to the protection data processing unit 22 for over-voltage and under-voltage protection of the circuit. The other end of the second capacitor C2 is grounded.

[0133] In this embodiment, by setting a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a second operational amplifier and a second capacitor in the first large current protection unit, the voltage signal of the first live wire A phase current after scaling processing is raised based on the reference voltage to obtain a first large current voltage signal, and the first large current voltage signal is sent to the first small current protection unit so that the first large current voltage signal amplifies the first large current voltage signal, and the first large current voltage signal is also sent to the protection data processing unit to perform over-voltage and under-voltage protection of the circuit.

[0134] Figure 8 A structural diagram of the first protection low current unit of the first processing unit of the second signal processing unit of the signal processing circuit of the circuit breaker provided in an embodiment of the present application is shown as follows: Figure 8 As shown, the first protection low current unit 2113 includes: a tenth resistor R 10 , the eleventh resistor R 11 , the third operational amplifier U3, the twelfth resistor R 12 , the thirteenth resistor R 13 and a third capacitor C3.

[0135] Optionally, refer to Figure 8 The first protection low current unit 2113 includes four resistors, an operational amplifier and a capacitor, respectively, the tenth resistor R 10 , the eleventh resistor R 11 , the twelfth resistor R 12 , the thirteenth resistor R 13 , the third operational amplifier U3 and the third capacitor C3. The first protection low current unit 2113 is connected to the tenth resistor R 10 , the eleventh resistor R 11 , the twelfth resistor R 12 , the thirteenth resistor R 13 , the third operational amplifier U3 and the third capacitor C3, based on the reference voltage VREF, the first large current voltage signal I A H is level-raised to obtain the first small current voltage signal I A L.

[0136] The tenth resistor R 10 One end of the tenth resistor R 10 The other end is connected to the eleventh resistor R11 and a first input terminal of the third operational amplifier U3.

[0137] Optionally, continue with reference to Figure 8 , the tenth resistor R 10 One end of the first protection low current unit 2113 is connected to the first output end of the first protection high current unit 2112 to receive a high current voltage signal I A H. Tenth resistor R 10 The other end is connected to the eleventh resistor R 11 and a first input terminal of the third operational amplifier U3.

[0138] The tenth resistor R 10 The other end is connected to the output end of the third operational amplifier U3 and the thirteenth resistor R 13 one end.

[0139] Optionally, continue with reference to Figure 8 , the tenth resistor R 10 The other end is connected to the output end of the third operational amplifier U3 and the thirteenth resistor R 13 one end.

[0140] The twelfth resistor R 12 One end of the resistor R 12 The other end is connected to the second input end of the third operational amplifier U3.

[0141] Optionally, continue with reference to Figure 8 , the twelfth resistor R 12 One end of the first protection low current unit 2113 is used as the second input end of the first protection low current unit 2113, and is connected to the reference voltage VREF. The third operational amplifier U3 includes two input ends, an output end, a positive power supply end, and a negative power supply end. The positive power supply end of the third operational amplifier U3 is used to connect to the positive electrode of the 3.3V power supply voltage +VDD, and the negative power supply end of the third operational amplifier U3 is grounded. The second input end of the third operational amplifier U3 is connected to the twelfth resistor R 12 the other end.

[0142] Thirteenth resistor R 13 The other end of the capacitor C3 is connected to one end of the third capacitor C3 and the input end of the protection data processing unit 22, and the other end of the third capacitor C3 is grounded.

[0143] Optionally, continue with reference to Figure 8 , the thirteenth resistor R 13 The other end of each is connected to one end of the third capacitor C3 and the input end of the protection data processing unit 22 to convert the first small current voltage signal I AL is sent to the protection data processing unit 22 for over-voltage and under-voltage protection of the circuit. The other end of the third capacitor C3 is grounded.

[0144] In this embodiment, by setting the tenth resistor, the eleventh resistor, the twelfth resistor, the thirteenth resistor, the third operational amplifier and the third capacitor in the first protection low current unit, the level of the first large current voltage signal is raised based on the reference voltage to obtain the first small current voltage signal, and the first small current voltage signal is sent to the protection data processing unit to perform over-voltage and under-voltage protection of the circuit.

[0145] Figure 9 Another structural diagram of the signal processing circuit of the circuit breaker provided in the embodiment of the present application is as follows Figure 9 As shown, the signal processing circuit of the circuit breaker further includes a power module 3. The power module 3 is connected to the first signal processing unit 11, the metering unit 12, the metering data processing unit 13, the second signal processing unit 21, the protection data processing unit 22 and the tripping unit 23 respectively.

[0146] Specifically, refer to Figure 9 The first signal processing unit 11, metering unit 12, metering data processing unit 13, second signal processing unit 21, protection data processing unit 22, and trip unit 23 each include a power supply terminal. The power supply module 3 is respectively connected to the power supply terminal of the first signal processing unit 11, the power supply terminal of the metering unit 12, the power supply terminal of the metering data processing unit 13, the power supply terminal of the second signal processing unit 21, the power supply terminal of the protection data processing unit 22, and the power supply terminal of the trip unit 23. The power supply module 3 is used to power the first signal processing unit 11, the metering unit 12, the metering data processing unit 13, the second signal processing unit 21, the protection data processing unit 22, and the trip unit 23.

[0147] The power module 3 obtains power from an external fast saturation transformer and an external power supply connected in parallel. Figure 9 The external speed-saturated transformers are connected in parallel with each other, and the external speed-saturated transformers and the external power supply are connected to the power module 3. The power supply module 3 is provided with power supply energy through two power supply modes: the external power supply and the external speed-saturated transformer.

[0148] Figure 10 Another structural diagram of the signal processing circuit of the circuit breaker provided in the embodiment of the present application is as follows Figure 10 As shown, the signal processing circuit of the circuit breaker further includes: a display control unit 14 , a display unit 15 and a communication unit 16 .

[0149] Optionally, refer to Figure 10The signal processing circuit of the circuit breaker further includes a display control unit 14, a display unit 15 and a communication unit 16. The display unit 15 is used to display data, the display control unit 14 is used to control the display unit 15, and the communication unit 16 is used for external communication.

[0150] The display control unit 14 is connected to the display unit 15 .

[0151] Optionally, continue with reference to Figure 10 The display control unit 14 is connected to the display unit 15 to send the data to be displayed to the display unit 15, and the display unit 15 displays the data to be displayed.

[0152] The metering data processing unit 13 , the display control unit 14 and the protection data processing unit 22 are connected to one end of the communication unit 16 via a controller area network bus, and the other end of the communication unit 16 is connected to an external device.

[0153] Optionally, continue with reference to Figure 10 The metering data processing unit 13, the display control unit 14 and the protection data processing unit 22 are connected to one end of the communication unit 16 via the Controller Area Network (CAN) bus. The communication unit 16 acts as a master station, and the metering data processing unit 13, the display control unit 14 and the protection data processing unit 22 act as slave stations. The metering data processing unit 13, the display control unit 14 and the protection data processing unit 22 send the data to be transmitted to the communication unit 16 via the CAN bus. The other end of the communication unit 16 is connected to an external device ( Figure 10 (not shown), the communication unit 16 outputs the data to be transmitted to the external device. For example, the external device can be a host computer.

[0154] Optionally, the metering data processing unit 13 , the display control unit 14 and the protection data processing unit 22 exchange data in the form of a CAN communication ad hoc network.

[0155] In this embodiment, a display control unit, a display unit, and a communication unit are provided in the signal processing circuit of the circuit breaker. The display control unit is connected to the display unit and sends data to be displayed to the display unit, which then displays the data to be displayed. The metering data processing unit, the display control unit, and the protection data processing unit are connected to one end of the communication unit via a controller area network bus. The communication unit acts as a master station, and the metering data processing unit, the display control unit, and the protection data processing unit act as slave stations. The metering data processing unit, the display control unit, and the protection data processing unit send data to be transmitted to the communication unit via the controller area network bus, and the communication unit outputs the data to be transmitted to an external device. Data exchange between the metering data processing unit, the display control unit, and the protection data processing unit is carried out in the form of a controller area network communication ad hoc network, thereby improving the efficiency of data exchange.

[0156] The present application also provides a circuit breaker, comprising the signal processing circuit, air-core mutual inductor and circuit breaker body of the circuit breaker described in the aforementioned embodiment.

[0157] The above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the protection scope of the present application.

Claims

1. A signal processing circuit for a circuit breaker, characterized in that: include: A metering module and a protection module, wherein the metering module includes: a first signal processing unit, a metering unit, and a metering data processing unit; and the protection module includes: a second signal processing unit, a protection data processing unit, and a tripping unit; The input end of the first signal processing unit is used to connect to the terminal of the air-core transformer, the output end of the first signal processing unit is connected to the input end of the metering unit, and the output end of the metering unit is connected to the input end of the metering data processing unit; the first signal processing unit is used to limit the voltage signal of the current from the air-core transformer and send the voltage signal after the limit processing to the metering unit for measurement; The input end of the second signal processing unit is used to connect to the terminal of the hollow core transformer, the output end of the second signal processing unit is connected to the input end of the protection data processing unit, and the output end of the protection data processing unit is connected to the input end of the tripping unit; the second signal processing unit is used to perform multiple amplitude conversions on the voltage signal of the current from the hollow core transformer to obtain a large current voltage signal and a small current voltage signal, and input the large current voltage signal and the small current voltage signal into the protection data processing unit for protection processing, wherein the voltage of the large current voltage signal is smaller than the voltage signal of the current of the hollow core transformer, and the voltage of the small current voltage signal is greater than the voltage signal of the current of the hollow core transformer.

2. The circuit according to claim 1, wherein: The first signal processing unit includes: a first metering clipping unit, a second metering clipping unit, a third metering clipping unit and a fourth metering clipping unit; The input end of the first measurement and limiting unit is connected to the voltage signal of the first live wire current of the terminal of the air-core transformer, the first output end of the first measurement and limiting unit is connected to the input end of the metering unit, and the second output end of the first measurement and limiting unit is grounded; The input end of the second measurement and limiting unit is connected to the voltage signal of the second live wire current of the terminal of the air-core transformer, the first output end of the second measurement and limiting unit is connected to the input end of the metering unit, and the second output end of the second measurement and limiting unit is grounded; The input end of the third measurement and limiting unit is connected to the voltage signal of the third live wire current of the terminal of the air-core transformer, the first output end of the third measurement and limiting unit is connected to the input end of the metering unit, and the second output end of the third measurement and limiting unit is grounded; The input end of the fourth metering limiter unit is connected to the voltage signal of the neutral current of the terminal of the air-core transformer, the first output end of the fourth metering limiter unit is connected to the input end of the metering unit, and the second output end of the fourth metering limiter unit is grounded.

3. The circuit according to claim 2, characterized in that The first metering limiter unit includes: a first resistor, a second resistor, a first bidirectional diode and a first capacitor; One end of the first resistor is connected to the voltage signal of the first live wire current of the connection terminal of the air-core transformer, and the other end of the first resistor is connected to one end of the second resistor and one end of the first bidirectional diode; The other end of the second resistor is connected to one end of the first capacitor and the input end of the metering unit; The other end of the first bidirectional diode and the other end of the first capacitor are grounded.

4. The circuit according to claim 1, characterized in that The second signal processing unit includes: a first processing unit, a second processing unit, a third processing unit and a fourth processing unit; The input end of the first processing unit is connected to the voltage signal of the first live wire current of the terminal of the air-core transformer, the first output end and the second output end of the first processing unit are both connected to the input end of the protection data processing unit, the first output end of the first processing unit is used to output a first large current voltage signal, and the second output end of the first processing unit is used to output a first small current voltage signal; The input end of the second processing unit is connected to the voltage signal of the second live wire current of the terminal of the air-core transformer, the first output end and the second output end of the second processing unit are both connected to the input end of the protection data processing unit, the first output end of the second processing unit is used to output the second large current voltage signal, and the second output end of the second processing unit is used to output the second small current voltage signal; The input end of the third processing unit is connected to the voltage signal of the third live wire current of the terminal of the air-core transformer, the first output end and the second output end of the third processing unit are both connected to the input end of the protection data processing unit, the first output end of the third processing unit is used to output the third large current voltage signal, and the second output end of the third processing unit is used to output the third small current voltage signal; The input end of the fourth processing unit is connected to the voltage signal of the neutral current of the terminal of the air-core transformer, the first output end and the second output end of the fourth processing unit are both connected to the input end of the protection data processing unit, the first output end of the fourth processing unit is used to output a fourth large current voltage signal, and the second output end of the fourth processing unit is used to output a fourth small current voltage signal.

5. The circuit according to claim 4, characterized in that The first processing unit includes: a first protection limiting unit, a first protection high current unit and a first protection low current unit; The input end of the first protection limiter unit is connected to the voltage signal of the first live wire current of the connection terminal of the air-core transformer, and the output end of the first protection limiter unit is connected to the first input end of the first protection high current unit; The second input terminal of the first large current protection unit is connected to the reference voltage, the first output terminal of the first large current protection unit is connected to the first input terminal of the first small current protection unit, and the second output terminal of the first large current protection unit is connected to the input terminal of the protection data processing unit; The second input terminal of the first protection low current unit is connected to the reference voltage, and the output terminal of the first protection low current unit is connected to the input terminal of the protection data processing unit.

6. The circuit according to claim 5, characterized in that The first protection limiter unit includes: a third resistor, a first operational amplifier and a fourth resistor; One end of the third resistor is connected to the voltage signal of the first live wire current of the connection terminal of the air-core transformer, and the other end of the third resistor is connected to one end of the fourth resistor and the first input end of the first operational amplifier; The second input terminal of the first operational amplifier is grounded, and the output terminal of the first operational amplifier is connected to the other end of the fourth resistor and the first input terminal of the first high-current protection unit.

7. The circuit according to claim 5, characterized in that The first high current protection unit includes: a fifth resistor, a sixth resistor, a second operational amplifier, a seventh resistor, an eighth resistor, a ninth resistor and a second capacitor; One end of the fifth resistor is connected to the output end of the first protection limiter unit, and the other end of the fifth resistor is connected to one end of the sixth resistor and the first input end of the second operational amplifier; The other end of the sixth resistor is connected to the output end of the second operational amplifier, one end of the ninth resistor and the first input end of the first protection low current unit; One end of the seventh resistor is connected to the reference voltage, and the other end of the seventh resistor is connected to one end of the eighth resistor and the second input end of the second operational amplifier; The other end of the eighth resistor is grounded; The other end of the ninth resistor is connected to one end of the second capacitor and the input end of the protection data processing unit; The other end of the second capacitor is grounded.

8. The circuit according to claim 5, characterized in that The first low current protection unit includes: a tenth resistor, an eleventh resistor, a third operational amplifier, a twelfth resistor, a thirteenth resistor and a third capacitor; One end of the tenth resistor is connected to the first output end of the first high-current protection unit, and the other end of the tenth resistor is connected to one end of the eleventh resistor and the first input end of the third operational amplifier; The other end of the tenth resistor is connected to the output end of the third operational amplifier and one end of the thirteenth resistor; One end of the twelfth resistor is connected to the reference voltage, and the other end of the twelfth resistor is connected to the second input end of the third operational amplifier; The other end of the thirteenth resistor is connected to one end of the third capacitor and the input end of the protection data processing unit; The other end of the third capacitor is grounded.

9. The circuit according to claim 1, wherein: The circuit further comprises: a display control unit, a display unit and a communication unit; The display control unit is connected to the display unit; The metering data processing unit, the display control unit and the protection data processing unit are connected to one end of the communication unit via a controller area network bus, and the other end of the communication unit is connected to an external device.

10. A circuit breaker, characterized in that: include: The signal processing circuit, air-core mutual inductor and circuit breaker body of a circuit breaker according to any one of claims 1 to 9.

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