Circuit breaker with self-checking function

Abstract

The utility model provides a kind of circuit breaker with self-checking function, and the circuit breaker with self-checking function includes reference source module, first switch module, ADC sampling module and processing module;Reference source module is electrically connected with the input end of ADC sampling module by first switch module, and first switch module is also electrically connected with the first output end of processing module, and the output end of ADC sampling module is electrically connected with the input end of processing module;Processing module is used to input the first reference voltage output by reference source module to ADC sampling module by first switch module, and according to the first ADC sampling voltage output by ADC sampling module, the first self-checking result of ADC sampling module is obtained.The utility model can realize the switching of ADC sampling module in working mode and self-checking mode based on the switch state of first switch module, and can be suitable for self-checking after the circuit breaker is shipped, to improve the reliability of the circuit breaker after shipment.

Description

Technical Field

[0001] This utility model relates to the field of circuit breaker technology, specifically to a circuit breaker with self-testing function. Background Technology

[0002] Circuit breakers provide protection by collecting electrical data from the busbar, such as controlling the internal trip unit to trip when abnormal electrical data occurs. It can be seen that the prerequisite for a circuit breaker to perform its protection function is the accurate acquisition of electrical data. When the relevant components used for data acquisition are damaged, it can cause the circuit breaker to malfunction or fail to operate. Therefore, ensuring the normal operation of the circuit breaker's data acquisition link is crucial.

[0003] Current technology typically only allows for the separation and individual testing of components within the data acquisition link before the circuit breaker leaves the factory, ensuring the internal data acquisition link is functioning correctly. However, during use, these components may suffer damage or aging, rendering traditional pre-shipment testing methods inapplicable and leading to reduced reliability of the circuit breaker after it leaves the factory. Utility Model Content

[0004] In view of the shortcomings of the existing technology, this utility model provides a circuit breaker with self-testing function.

[0005] In one embodiment, the present invention provides a circuit breaker with self-testing function, comprising a reference source module, a first switch module, an ADC sampling module, and a processing module;

[0006] The reference source module is electrically connected to the input terminal of the ADC sampling module through the first switch module. The first switch module is also electrically connected to the first output terminal of the processing module. The output terminal of the ADC sampling module is electrically connected to the input terminal of the processing module.

[0007] The processing module is used to input the first reference voltage output by the reference source module to the ADC sampling module through the first switch module, and obtain the first self-test result of the ADC sampling module based on the first ADC sampling voltage output by the ADC sampling module.

[0008] In one embodiment, the first switching module includes a first analog switch;

[0009] The first input terminal of the first analog switch is electrically connected to the reference source module, the second input terminal of the first analog switch is electrically connected to the input terminal of the ADC sampling module, and the controlled terminal of the first analog switch is electrically connected to the first output terminal of the processing module.

[0010] In one embodiment, the circuit breaker with self-testing function further includes a second switching module and a signal conditioning module;

[0011] The reference source module is also electrically connected to the input terminal of the signal conditioning module through the second switch module. The second switch module is also electrically connected to the second output terminal of the processing module. The output terminal of the signal conditioning module is electrically connected to the input terminal of the ADC sampling module.

[0012] The processing module is also used to input the second reference voltage output by the reference source module to the signal conditioning module through the second switch module when the first self-test result indicates that the ADC sampling module is normal, and to obtain the second self-test result of the signal conditioning module based on the second ADC sampling voltage output by the ADC sampling module.

[0013] In one embodiment, the second switching module includes a second analog switch;

[0014] The first input terminal of the second analog switch is electrically connected to the reference source module, the second input terminal of the second analog switch is electrically connected to the input terminal of the signal conditioning module, and the controlled terminal of the second analog switch is electrically connected to the second output terminal of the processing module.

[0015] In one embodiment, the circuit breaker with self-testing function further includes a current transformer and a first pull-down resistor;

[0016] The current transformer is electrically connected to the first pull-down resistor and the input terminal of the signal conditioning module, respectively.

[0017] The processing module is also used to obtain the third self-test result of the current transformer based on the third ADC sampling voltage output by the ADC sampling module when the second self-test result characterization signal conditioning module is normal.

[0018] In one embodiment, the circuit breaker with self-testing function further includes a power supply protection module and a power processing module;

[0019] The input terminal of the power supply protection module is used to connect to the power supply, and the output terminal of the power supply protection module is electrically connected to the input terminal of the power processing module to output protection power. The output terminal of the power processing module is electrically connected to the power supply terminal of the reference source module, the power supply terminal of the first switch module, the power supply terminal of the ADC sampling module, and the power supply terminal of the processing module, respectively.

[0020] The power supply protection module is used to control the state between its input and output terminals to a target state when the power supply is abnormal, so as to limit the output protective power.

[0021] In one embodiment, the power supply protection module includes an overvoltage protection unit;

[0022] The input terminal of the overvoltage protection unit is used to connect to the power supply, and the output terminal of the overvoltage protection unit is used to output the protection power supply.

[0023] The overvoltage protection unit is used to disconnect the line between its input and output terminals when the voltage of the power supply exceeds a preset voltage protection threshold.

[0024] In one embodiment, the overvoltage protection unit includes a PMOS transistor, a first PNP transistor, a second pull-down resistor, a first voltage divider resistor, and a second voltage divider resistor.

[0025] The source of the PMOS transistor, the emitter of the first PNP transistor, and the first terminal of the first voltage divider resistor are respectively used to connect to the power supply. The second terminal of the first voltage divider resistor is electrically connected to the base of the first PNP transistor and the first terminal of the second voltage divider resistor. The collector of the first PNP transistor is electrically connected to the gate of the PMOS transistor and the first terminal of the second pull-down resistor. The drain of the PMOS transistor is used to output the protection power supply. The second terminal of the second voltage divider resistor and the second terminal of the second pull-down resistor are respectively used to ground.

[0026] In one embodiment, the power supply protection module includes an overcurrent protection unit;

[0027] The input terminal of the overcurrent protection unit is used to connect to the power supply, and the output terminal of the overcurrent protection unit is used to output the protection power supply.

[0028] The overcurrent protection unit increases the impedance between its input and output terminals when the current in the line between its input and output terminals exceeds a preset current protection threshold.

[0029] In one embodiment, the overcurrent protection unit includes a PMOS transistor, a second PNP transistor, a second pull-down resistor, and a voltage drop resistor;

[0030] The source of the PMOS transistor is electrically connected to the first terminal of the voltage drop resistor and the base of the second PNP transistor, respectively. The second terminal of the voltage drop resistor and the emitter of the second PNP transistor are used to connect to the power supply. The collector of the second PNP transistor is electrically connected to the gate of the PMOS transistor and the first terminal of the second pull-down resistor, respectively. The drain of the PMOS transistor is used to output the protection power supply, and the second terminal of the second pull-down resistor is used to ground.

[0031] The circuit breaker with self-testing function described above includes a first switching module for its ADC sampling module. When a self-test of the ADC sampling module is required, the processing module can input the first reference voltage output from the reference source module to the ADC sampling module through the first switching module. Provided the first reference voltage is accurate, the first ADC sampling voltage output by the ADC sampling module can be compared with the first reference voltage, and the first self-test result of the ADC sampling module can be obtained based on the comparison result. This invention can switch the ADC sampling module between operating mode and self-testing mode based on the switching state of the first switching module, making it suitable for self-testing of circuit breakers after they leave the factory, thus improving the reliability of the circuit breaker after it leaves the factory. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the structure of a circuit breaker with self-testing function in one embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of a circuit breaker with self-testing function in one embodiment of the present invention, which also includes a signal conditioning module and a second switching module;

[0035] Figure 3 This is a schematic diagram of the A-phase large-range conditioning subunit in one embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the specific circuit of the A-phase small-range conditioning subunit in one embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the specific circuit of the A-phase small-range conditioning subunit in another embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of the specific circuit of the first reference source unit in one embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of the specific circuit of the second reference source unit in one embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of the analog switch in one embodiment of the present invention;

[0041] Figure 9 This is a schematic diagram showing the connection between the power supply protection module and the power processing module in one embodiment of the present invention;

[0042] Figure 10 This is a schematic diagram of the power supply protection module in one embodiment of the present invention;

[0043] Figure 11 This is a flowchart illustrating the self-testing method of a circuit breaker in one embodiment of the present invention. Detailed Implementation

[0044] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0045] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified. In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to implement and use this invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this invention can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of this invention with unnecessary detail. Therefore, this invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0046] Firstly, such as Figure 1 As shown, in one embodiment, the present invention provides a circuit breaker with self-testing function, including a reference source module, a first switch module, an ADC sampling module, and a processing module.

[0047] The ADC sampling module refers to the analog-to-digital converter, which converts the input analog voltage into a digital voltage so that it can be read and processed by the processing module.

[0048] The processing module includes, but is not limited to, a microcontroller.

[0049] The reference source module is electrically connected to the input terminal of the ADC sampling module through the first switch module. The first switch module is also electrically connected to the first output terminal of the processing module. The output terminal of the ADC sampling module is electrically connected to the input terminal of the processing module.

[0050] The switching state of the first switch module is controlled by the processing module. When the first switch module is in the on state, the input terminal of the reference source module is connected to the input terminal of the ADC sampling module, so that the ADC sampling module enters the self-test mode. At this time, the output of the ADC sampling module is determined by the output of the reference source module and the sampling strategy of the ADC sampling module itself. Conversely, when the first switch module is in the off state, the input terminal of the reference source module is not connected to the input terminal of the ADC sampling module, so that the ADC sampling module enters the working mode. At this time, the output of the ADC sampling module is determined by the output of the preceding signal conditioning module and the sampling strategy of the ADC sampling module itself.

[0051] The processing module is used to input the first reference voltage output by the reference source module to the ADC sampling module through the first switch module, and obtain the first self-test result of the ADC sampling module based on the first ADC sampling voltage output by the ADC sampling module.

[0052] When the ADC sampling module needs to perform a self-test, the processing module can control the first switch module to be in the on state, so that the reference voltage VREF0 output by the reference source module can be input to the ADC sampling module through the first switch module. At this time, the reference voltage VREF0 output by the reference source module can be understood as the first reference voltage. The processing module pre-stores the reference voltage VREF0. Under the premise that the reference voltage VREF0 output by the reference source module is accurate (i.e., the actual value of the reference voltage VREF0 is consistent with the stored value in the processing module), if the ADC sampling module is normal, the ADC sampling voltage ADC0 output by the ADC sampling module is consistent with the reference voltage VREF0 stored in the processing module; conversely, if the ADC sampling module is abnormal, the ADC sampling voltage ADC0 output by the ADC sampling module is inconsistent with the reference voltage VREF0 stored in the processing module. At this time, the ADC sampling voltage ADC0 output by the ADC sampling module can be understood as the first ADC sampling voltage.

[0053] It should be noted that the reference voltage VREF0 directly output by the reference source module can be either an analog or digital quantity. However, the processing module stores the reference voltage VREF0 as a digital quantity. Furthermore, the ADC sampling voltage ADC0 output by the ADC sampling module is also a digital quantity. Therefore, the processing module can directly compare the ADC sampling voltage ADC0 with the value recorded when storing the reference voltage VREF0 to obtain the corresponding first comparison result.

[0054] Based on the above analysis, it can be seen that when the first comparison result indicates that the recorded values ​​of the ADC sampling voltage ADC0 and the storage reference voltage VREF0 are consistent, the first self-test result indicating that the ADC sampling module is normal can be obtained; conversely, when the first comparison result indicates that the recorded values ​​of the ADC sampling voltage ADC0 and the storage reference voltage VREF0 are inconsistent, the first self-test result indicating that the ADC sampling module is abnormal can be obtained.

[0055] The circuit breaker with self-testing function described above includes a first switching module for its ADC sampling module. When a self-test of the ADC sampling module is required, the processing module can input the first reference voltage output from the reference source module to the ADC sampling module through the first switching module. Provided the first reference voltage is accurate, the first ADC sampling voltage output by the ADC sampling module can be compared with the first reference voltage, and the first self-test result of the ADC sampling module can be obtained based on the comparison result. This invention can switch the ADC sampling module between operating mode and self-testing mode based on the switching state of the first switching module, making it suitable for self-testing of circuit breakers after they leave the factory, thus improving the reliability of the circuit breaker after it leaves the factory.

[0056] In one embodiment, the first switching module includes a first analog switch;

[0057] The first input terminal of the first analog switch is electrically connected to the reference source module, the second input terminal of the first analog switch is electrically connected to the input terminal of the ADC sampling module, and the controlled terminal of the first analog switch is electrically connected to the first output terminal of the processing module.

[0058] Among them, the use of analog switches can realize the self-test of each sampling channel of the ADC sampling module based on the multi-channel characteristics of analog switches, thereby improving the integration of the circuit breaker while realizing the comprehensive self-test of the ADC sampling module.

[0059] like Figure 2 As shown, in one embodiment, the circuit breaker with self-testing function further includes a second switching module and a signal conditioning module.

[0060] The signal conditioning module is mainly used to scale the analog voltage output by the front-end module (such as the current sampling module or voltage sampling module) to meet the sampling requirements of the subsequent ADC sampling module.

[0061] The reference source module is also electrically connected to the input terminal of the signal conditioning module through the second switch module. The second switch module is also electrically connected to the second output terminal of the processing module. The output terminal of the signal conditioning module is electrically connected to the input terminal of the ADC sampling module.

[0062] Similar to the first switch module, the switching state of the second switch module is also controlled by the processing module. When the second switch module is in the on state, the input terminals of the reference source module and the signal conditioning module are connected, so that the signal conditioning module enters the self-test mode. At this time, the output of the signal conditioning module is determined by the output of the reference source module and the conditioning strategy of the signal conditioning module itself. Conversely, when the second switch module is in the off state, the input terminals of the reference source module and the signal conditioning module are not connected, so that the signal conditioning module enters the working mode. At this time, the output of the signal conditioning module is determined by the output of the preceding module and the conditioning strategy of the signal conditioning module itself.

[0063] The processing module is also used to input the second reference voltage output by the reference source module to the signal conditioning module through the second switch module when the first self-test result indicates that the ADC sampling module is normal, and to obtain the second self-test result of the signal conditioning module based on the second ADC sampling voltage output by the ADC sampling module.

[0064] When the signal conditioning module needs to perform a self-test, the processing module can control the first switch module to be in the off state and the second switch module to be in the on state. This allows the reference voltage VREF0 output from the reference source module to be input to the signal conditioning module via the second switch module. At this time, the reference voltage VREF0 output from the reference source module can be understood as the second reference voltage. The second reference voltage and the first reference voltage will not appear simultaneously; therefore, they can be the same or different. Since the output of the signal conditioning module needs to be converted from analog to digital by the ADC sampling module before it can be read by the processing module, it is necessary to ensure that the ADC sampling module is functioning correctly during the self-test of the signal conditioning module.

[0065] Under the premise that the ADC sampling module is normal, if the signal conditioning module is normal, the relationship between the ADC sampling voltage ADC0 output by the ADC sampling module and the reference voltage VREF0 stored in the processing module meets the preset requirements, that is, the actual multiple between the two is consistent with the preset multiple of the signal conditioning module; conversely, if the signal conditioning module is abnormal, the relationship between the ADC sampling voltage ADC0 output by the ADC sampling module and the reference voltage VREF0 stored in the processing module does not meet the preset requirements. In this case, the ADC sampling voltage ADC0 output by the ADC sampling module can be understood as the second ADC sampling voltage.

[0066] Furthermore, the processing module can directly compare the ADC sampling voltage ADC0 with the value recorded when storing the reference voltage VREF0 to obtain the corresponding second comparison result.

[0067] Based on the above analysis, it can be seen that when the relationship between the recorded values ​​of the ADC sampling voltage ADC0 and the storage reference voltage VREF0 obtained by the second comparison result meets the preset requirements, a second self-test result indicating that the signal conditioning module is normal can be obtained; conversely, when the relationship between the recorded values ​​of the ADC sampling voltage ADC0 and the storage reference voltage VREF0 obtained by the second comparison result does not meet the preset requirements, a second self-test result indicating that the signal conditioning module is abnormal can be obtained.

[0068] In one embodiment, the second switching module includes a second analog switch;

[0069] The first input terminal of the second analog switch is electrically connected to the reference source module, the second input terminal of the second analog switch is electrically connected to the input terminal of the signal conditioning module, and the controlled terminal of the second analog switch is electrically connected to the second output terminal of the processing module.

[0070] Since the signal conditioning module typically includes multiple signal conditioning units for each phase of the power grid, the use of analog switches allows for self-testing of each signal conditioning unit based on the multi-channel characteristics of analog switches. This improves the integration of the circuit breaker while achieving comprehensive self-testing of the signal conditioning module.

[0071] To clarify the self-test scheme of the signal conditioning module, a detailed explanation is provided based on its specific structure. Taking phase A of the power grid as an example, the signal conditioning module includes a phase A signal conditioning unit. For example... Figure 3 and Figure 4 As shown, the A-phase signal conditioning unit includes an A-phase large-range conditioning sub-unit composed of resistors R40, R41, R37, capacitor C20, operational amplifier U1D, resistor R42, and capacitor C21, and an A-phase small-range conditioning sub-unit composed of resistors R43, R46, R39, operational amplifier U2D, resistor R45, and capacitor C22.

[0072] In this system, the common terminal of resistors R40 and R41 in the large-range conditioning subunit of phase A is electrically connected to the reference source module via a second switching module, so as to access the phase A reference voltage IA output by the reference source module through the second switching module. The output terminal of operational amplifier U1D is electrically connected to the large-range input terminal of the ADC sampling module of phase A through an RC circuit composed of resistor R42 and capacitor C21, so as to output the large-range conditioning voltage MAX_IA of phase A. The output terminal of operational amplifier U1D is also electrically connected to resistor R46 in the small-range conditioning subunit of phase A, so as to output the intermediate conditioning voltage RC_IA of phase A. This allows operational amplifier U2D in the large-range conditioning subunit of phase A to be electrically connected to the small-range input terminal of the ADC sampling module of phase A based on the accessed intermediate conditioning voltage RC_IA of phase A, through an RC circuit composed of resistor R45 and capacitor C22, so as to output the small-range conditioning voltage MIN_IA of phase A. Specifically, when the A-phase reference voltage IA is 2V, resistor R41 is 110KΩ, and resistor R37 is 270KΩ, and the A-phase large-range conditioning subunit is functioning normally, based on the conditioning factor of the A-phase large-range conditioning subunit, the processing module obtains the A-phase large-range ADC sampling voltage through the ADC sampling module as 1.5V - (2V - 1.5V) / 110K * 270K = 0.273V. Therefore, the processing module can determine whether the A-phase large-range conditioning subunit is functioning normally based on whether the read A-phase large-range ADC sampling voltage matches 0.273V.

[0073] Since the input of the A-phase small-range conditioning subunit is the output of the A-phase large-range conditioning subunit, it is necessary to ensure the A-phase large-range conditioning subunit is functioning correctly before further determining whether the A-phase small-range conditioning subunit is working properly. Assuming the A-phase large-range conditioning subunit is functioning correctly, when the A-phase small-range conditioning subunit is functioning correctly, based on the conditioning factor of the A-phase small-range conditioning subunit, the processing module obtains the A-phase small-range ADC sampling voltage through the ADC sampling module as 0.273V * 7.5 = 2.045V. Therefore, the processing module can determine whether the A-phase small-range conditioning subunit is functioning correctly based on whether the read A-phase small-range ADC sampling voltage matches 2.045V.

[0074] As mentioned in the above embodiments, since the large-range conditioning subunit of phase A and the small-range conditioning subunit of phase A are connected in series, the self-test of the small-range conditioning subunit of phase A can only be performed after the large-range conditioning subunit of phase A has completed its self-test and is functioning normally. This is because the reference voltage IA of phase A provided by the reference source module is only input to the input terminal of the large-range conditioning subunit of phase A. In other embodiments, the reference source module can provide the corresponding reference voltage to the input terminal of the small-range conditioning subunit of phase A through an additional third switching module. This allows the self-test of the small-range conditioning subunit of phase A to be performed directly based on the reference voltage input to the small-range conditioning subunit of phase A, without requiring the self-test of the large-range conditioning subunit of phase A as a prerequisite.

[0075] Specifically, such as Figure 3 As shown, when the circuit breaker with self-test function also includes a current transformer connected to terminal TP15, the end of resistor R40 furthest from resistor R41 is electrically connected to the first terminal IA+ of the current transformer, the end of resistor R41 furthest from resistor R40 is electrically connected to the inverting input terminal of operational amplifier U1D, and the non-inverting input terminal of operational amplifier U1D is electrically connected to the second terminal IA- of the current transformer. That is, referring to... Figure 3 and Figure 4 It can be seen that the input terminal of the large-range conditioning subunit of phase A is electrically connected to the current transformer, and the output terminal of the large-range conditioning subunit of phase A is electrically connected to the input terminal of the small-range conditioning subunit of phase A.

[0076] In other embodiments, the large-range conditioning subunit of phase A and the small-range conditioning subunit of phase A can also be connected in parallel, that is, the large-range conditioning subunit of phase A and the small-range conditioning subunit of phase A are independently connected to the analog voltage output by the front-end module.

[0077] Specifically, such as Figure 5 As shown, the A-phase small-range conditioning subunit at this time consists of resistor R36, resistor R34, capacitor C40, operational amplifier U5D, resistor R51, and capacitor C35. One end of resistor R36 is electrically connected to the first terminal IA+ of the current transformer, and the other end of resistor R36 is electrically connected to the inverting input terminal of operational amplifier U5D. The non-inverting input terminal of operational amplifier U5D is electrically connected to the second terminal IA- of the current transformer. That is to say, referring to... Figure 3 and Figure 5 It can be seen that the input terminals of the large-range conditioning subunit of phase A and the small-range conditioning subunit of phase A are electrically connected to the current transformer.

[0078] When a parallel configuration is used, if either the large-range conditioning subunit or the small-range conditioning subunit of phase A fails, the other will not be affected, thereby improving conditioning reliability.

[0079] like Figure 3As shown, in one embodiment, taking phase A as an example, the circuit breaker with self-test function also includes a current transformer connected to terminal TP15 and a first pull-down resistor R38.

[0080] The first terminal IA+ of the current transformer is electrically connected to the first pull-down resistor R38 and the resistor R40, respectively. The second terminal IA- of the current transformer is connected to the non-inverting input terminal of the operational amplifier U1D, respectively, for connecting to the reference voltage 1.5V.

[0081] The processing module is also used to obtain the third self-test result of the current transformer based on the third ADC sampling voltage output by the ADC sampling module when the second self-test result characterization signal conditioning module is normal.

[0082] As mentioned in the above embodiments, the second self-test result is obtained only after the first self-test result indicates that the ADC sampling module is normal. Therefore, in this embodiment, it is limited to the second self-test result indicating that the signal conditioning module is normal, which means that both the signal conditioning module and the ADC sampling module are normal.

[0083] When the current transformer is normally connected, the coil of the current transformer is equivalent to a small resistor. At this time, the voltages at the two input terminals of the operational amplifier U1D are equal, that is, V+=V-=1.5V. The output A-phase large-range conditioning voltage MAX_IA and the A-phase large-range ADC sampling voltage are also 1.5V respectively. Similarly, when the current transformer is abnormally connected (including disconnection or non-connection), the operational amplifier U1D is an amplifier. Due to the presence of the first pull-down resistor R49, the output A-phase large-range conditioning voltage MAX_IA and the A-phase large-range ADC sampling voltage are 1.5V*(1+R37 / (R38+R40+R41)). If R37, R38, R40, and R41 are 270KΩ, 100KΩ, 470KΩ, and 110KΩ respectively, then the voltage is 1.5V*(1+270 / (100+470+110))≈2.096V. Therefore, the processing module can determine whether the current transformer is normal by whether the large-range ADC sampling voltage of phase A is consistent with 2.096V.

[0084] like Figure 6 and Figure 7 As shown, in one embodiment, the reference source module includes a first reference source unit composed of resistor R8, resistor R12, capacitor C10, operational amplifier U1A, capacitor C3, capacitor C5, resistor R6, resistor R10, capacitor C7, capacitor C8 and capacitor C11, and a second reference source unit composed of resistor R9, resistor R13, capacitor C12, operational amplifier U2A, resistor R7, capacitor C4, capacitor C6, resistor R11 and capacitor C9.

[0085] The first reference source unit is used to perform amplitude conversion based on the initial reference voltage VREF_+3V, thereby outputting a reference voltage of 1.5V to... Figure 3 and Figure 4 The signal conditioning module shown in the figure is provided.

[0086] The second reference source unit is used to perform amplitude conversion based on the initial reference voltage VREF_+3V, thereby outputting a reference voltage VREF_+2V, which is then transmitted to the second switching module. Figure 3 The signal conditioning module shown provides the reference voltage IA for phase A.

[0087] Specifically, such as Figure 8 As shown, the second switching module includes an analog switch U1. The input terminal COM of analog switch U1 is used to connect to the reference voltage VREF_+2V, and the A-phase output terminal NO1 of analog switch U1 is used to output the A-phase reference voltage IA. The enable terminal of analog switch U1 is used to connect to the enable control signal TEST_ADC_EN output by the processing module. Therefore, under the control of the processing module, analog switch U1 can connect its input terminal COM and the A-phase output terminal NO1, thereby outputting the reference voltage VREF_+2V to... Figure 3 The signal conditioning module shown outputs the A-phase reference voltage IA.

[0088] like Figure 9 As shown, in one embodiment, the circuit breaker with self-testing function further includes a power supply protection module and a power processing module.

[0089] The power processing module is used to perform amplitude conversion in order to provide each power-consuming module with the power required for its amplitude.

[0090] The input terminal of the power supply protection module is used to connect to the power supply VCC. The output terminal of the power supply protection module is electrically connected to the input terminal of the power processing module to output the protection power supply VCC+. The output terminal of the power processing module is electrically connected to the power supply terminals of the reference source module, the first switch module, the ADC sampling module, and the processing module to output the working power supply (such as 1.5V, 3.3V, and 5V).

[0091] The power supply protection module is used to control the state between its input and output terminals to a target state when the power supply is abnormal, so as to limit the output protective power.

[0092] Power supply anomalies include overvoltage or overcurrent. Overvoltage is usually caused by abnormal sudden changes in the power supply VCC, while overcurrent is usually caused by a large number of downstream power-consuming modules being powered on at the same time. Regardless of the type of anomaly, it may affect the safety and reliability of the circuit breaker. Therefore, when a power supply anomaly occurs, by controlling the state between the input and output terminals of the power supply protection module as the target state to limit the output protection power supply, the power supply of downstream power-consuming modules can be protected in a timely manner.

[0093] In one embodiment, the power supply protection module includes an overvoltage protection unit. The input terminal of the overvoltage protection unit is used to connect to the power supply, and the output terminal of the overvoltage protection unit is used to output protective power. The overvoltage protection unit is used to disconnect the line between its input terminal and output terminal when the voltage of the power supply exceeds a preset voltage protection threshold.

[0094] Specifically, such as Figure 10 As shown, the overvoltage protection unit includes a PMOS transistor Q1, a first PNP transistor Q2, a second pull-down resistor R5, a first voltage divider resistor R2, and a second voltage divider resistor R4.

[0095] The source Q1 of the PMOS transistor, the emitter of the first PNP transistor Q2, and the first terminal of the first voltage divider resistor R2 are respectively used to connect to the power supply (such as a 12V power supply). The second terminal of the first voltage divider resistor R2 is electrically connected to the base of the first PNP transistor Q2 through resistor R3 and is also electrically connected to the first terminal of the second voltage divider resistor R4. The collector of the first PNP transistor Q2 is electrically connected to the gate of the PMOS transistor Q1 and the first terminal of the second pull-down resistor R5 through diode D4. The drain of the PMOS transistor Q1 is used to output the protection power supply (such as a +12V protection power supply). The second terminal of the second voltage divider resistor R4 and the second terminal of the second pull-down resistor R5 are respectively used to ground.

[0096] When the power supply is operating within its rated range, the first PNP transistor Q2 is in the off state, and the PMOS transistor Q1 is in the on state due to the second pull-down resistor R5, thus achieving normal power supply. When an overvoltage occurs in the power supply, the voltage division by the first voltage divider resistor R2 and the second voltage divider resistor R4 causes the first PNP transistor Q2 to be in the on state. At this time, the gate voltage of the PMOS transistor Q1 is approximately equal to its source voltage, causing the PMOS transistor Q1 to be in the off state, thus interrupting the power supply.

[0097] In one embodiment, the power supply protection module includes an overcurrent protection unit. The input terminal of the overcurrent protection unit is used to connect to the power supply, and the output terminal of the overcurrent protection unit is used to output protective power. The overcurrent protection unit is used to increase the impedance between its input terminal and output terminal when the current on the line between its input terminal and output terminal exceeds a preset current protection threshold.

[0098] Specifically, such as Figure 10 As shown, the overcurrent protection unit includes a PMOS transistor Q1, a second PNP transistor Q3, a second pull-down resistor R5, and a voltage drop resistor R1.

[0099] The source of PMOS transistor Q1 is electrically connected to the first terminal of voltage drop resistor R1 and the base of second PNP transistor Q3 through diode D1. The second terminal of voltage drop resistor R1 and the emitter of second PNP transistor Q3 are used to connect to the power supply (such as a 12V power supply). The collector of second PNP transistor Q3 is electrically connected to the gate of PMOS transistor Q1 and the first terminal of second pull-down resistor R5 through diode D3. The drain of PMOS transistor Q1 is used to output protection power (such as a +12V protection power supply). The second terminal of second pull-down resistor R5 is used to ground.

[0100] When power is supplied to the power modules, current flows through the voltage drop resistor R1, creating a voltage drop across it. When there are many power modules, the current increases. When the voltage drop across R1 exceeds the turn-on voltage (e.g., 0.6V) of the second PNP transistor Q3, Q3 is turned on and operates in the amplification region, forming a voltage divider with the second pull-down resistor R5. The larger the current, the lower the turn-on voltage drop of Q3, and the larger the on-resistance of the PMOS transistor Q1 (operating in the amplification region). This allows for automatic adjustment of the on-resistance of the PMOS transistor Q1 to control the current.

[0101] In this circuit, diode D1 is used to prevent reverse connection, while capacitor C1 and diode D2 provide secondary protection to absorb surge residual voltage and prevent damage to PMOS transistor Q1.

[0102] Secondly, in one embodiment, the present invention provides a self-testing method for a circuit breaker, applicable to a circuit breaker with self-testing function in any of the above embodiments; see reference. Figure 1 The circuit breaker's self-test method includes the following steps performed by the processing module:

[0103] In response to the first self-test command, the first switch module is controlled to be in the on state so that the first reference voltage output by the reference source module is input to the ADC sampling module.

[0104] The first self-test command can be generated based on the power-on of the circuit breaker or based on user input.

[0105] Obtain the first ADC sampling voltage output by the ADC sampling module, and determine the first self-test result of the ADC sampling module based on the first reference voltage and the first ADC sampling voltage.

[0106] Since the ADC sampling module is closest to the processing module in the acquisition link, it needs to perform self-test first to ensure that it can subsequently perform self-tests on other modules in the preceding stage. The specific self-test principle can be referred to the relevant embodiments mentioned above, and will not be repeated here.

[0107] In one embodiment, refer to Figure 2 The circuit breaker's self-test method also includes the following steps performed by the processing module:

[0108] In response to the second self-test command, when the first self-test result indicates that the ADC sampling module is normal, the first switch module is controlled to be in the off state and the second switch module is in the on state, so that the second reference voltage output by the reference source module is input to the signal conditioning module.

[0109] In this embodiment, when the first self-test result indicates an abnormality in the ADC sampling module, the output of the signal conditioning module needs to be transmitted to the processing module through the ADC sampling module, making it impossible to determine the status of the signal conditioning module under these circumstances. Therefore, this embodiment only performs a self-test on the signal conditioning module when the first self-test result indicates that the ADC sampling module is normal.

[0110] The purpose of keeping the first switch module in the off state is to ensure that the output of the ADC sampling module is generated based on the output of the signal conditioning module.

[0111] The second self-test instruction can be generated based on the result of the first self-test or based on user input.

[0112] Obtain the second ADC sampling voltage output by the ADC sampling module, and determine the second self-test result of the signal conditioning module based on the second reference voltage and the second ADC sampling voltage.

[0113] Under the premise that the ADC sampling module is normal, there is no need to consider the ADC sampling module. At this time, the signal conditioning module is the closest to the processing module in the acquisition link, so it needs to perform self-test first to ensure that it can perform self-test on other modules in front of it. The specific self-test principle can be referred to the above-mentioned relevant embodiments, which will not be repeated here.

[0114] In one embodiment, refer to Figure 3 The circuit breaker's self-test method also includes the following steps performed by the processing module:

[0115] In response to the third self-test command, when the second self-test result indicates that the signal conditioning module is normal, the first switch module and the second switch module are controlled to be in the off state respectively.

[0116] In this embodiment, when the first self-test result indicates an abnormality in the ADC sampling module or the second self-test result indicates an abnormality in the signal conditioning module, the transformer's output needs to be transmitted to the processing module through both the signal conditioning module and the ADC sampling module, making it impossible to determine the transformer's state under these circumstances. Therefore, this embodiment only performs a self-test on the transformer when the first self-test result indicates that the ADC sampling module is functioning normally and the second self-test result indicates that the signal conditioning module is functioning normally.

[0117] The purpose of controlling the first switch module to be in the off state and the second switch module to be in the off state is to ensure that the output of the ADC sampling module is generated based on the output of the mutual inductor.

[0118] The third self-test instruction can be generated based on the result of the second self-test or based on user input.

[0119] Obtain the third ADC sampling voltage output by the ADC sampling module, and determine the third self-test result of the current transformer based on the third ADC sampling voltage.

[0120] Under the premise that the ADC sampling module and the signal conditioning module are normal, there is no need to consider the ADC sampling module and the signal conditioning module. At this time, the current transformer is the closest to the processing module in the acquisition link, so it can reliably perform self-test. The specific self-test principle can be referred to the above-mentioned relevant embodiments, which will not be repeated here.

[0121] To make the above self-testing method clearer, the above embodiments will now be described in combination. For example... Figure 11 As shown, in one embodiment, the self-testing method of the circuit breaker includes:

[0122] After entering the circuit breaker self-test process, the first analog switch is first controlled to be in the conducting state and the first ADC sampling voltage output by the ADC sampling module is read.

[0123] If the first ADC sampling voltage does not meet the requirements, the first self-test result, which indicates an abnormality in the ADC sampling module, is obtained. The test result is recorded and reported, and the self-test ends.

[0124] If the first ADC sampling voltage meets the requirements, the first self-test result, which indicates that the ADC sampling module is normal, is obtained. Then, the first analog switch is controlled to be in the off state and the second analog switch is in the on state, and the second ADC sampling voltage output by the ADC sampling module is read.

[0125] If the sampling voltage of the second ADC does not meet the requirements, a second self-test result indicating an abnormality in the signal conditioning module is obtained. The test result is recorded and reported, and the self-test ends.

[0126] If the second ADC sampling voltage meets the requirements, a second self-test result indicating that the signal conditioning module is normal is obtained. Then, the first analog switch is controlled to be in the open state and the second analog switch is in the open state, and the third ADC sampling voltage output by the ADC sampling module is read.

[0127] If the third ADC sampling voltage does not meet the requirements, the third self-test result characterizing the transformer abnormality is obtained. The test result is recorded and reported, and the self-test ends.

[0128] If the third ADC sampling voltage meets the requirements, the third self-test result, which indicates that the transformer is normal, is obtained. The test result is recorded and reported, and the self-test ends.

[0129] As a supplement, circuit breakers are usually equipped with multiple acquisition links for each phase of the power grid. Each acquisition link includes a corresponding transformer, signal conditioning module and ADC sampling module. When the above method is used to perform self-test on each module in the acquisition link, if the ADC sampling voltage corresponding to each acquisition link does not meet the requirements and the deviation of each ADC sampling voltage is the same, a fourth self-test result that characterizes the abnormality of the reference source module can be obtained.

[0130] Specifically, taking the self-test of the ADC sampling module as an example, when performing a self-test on multiple ADC sampling modules, the first reference voltage output by the reference source module is input to the corresponding ADC sampling module through multiple first switch modules, and the first self-test results corresponding to the multiple ADC sampling modules are obtained based on the multiple first ADC sampling voltages output by the multiple ADC sampling modules respectively.

[0131] If the sampling voltage of each first ADC is inconsistent with the corresponding first reference voltage and the degree of deviation is the same, then the fourth self-test result characterizing the abnormality of the reference source module is obtained.

[0132] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0133] The above provides a detailed description of a circuit breaker with self-testing function and a self-testing method for the circuit breaker provided by this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

[0134] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A circuit breaker with self-testing function, characterized in that, The circuit breaker with self-testing function includes a reference source module, a first switch module, an ADC sampling module, and a processing module. The reference source module is electrically connected to the input terminal of the ADC sampling module through the first switch module. The first switch module is also electrically connected to the first output terminal of the processing module. The output terminal of the ADC sampling module is electrically connected to the input terminal of the processing module. The processing module is used to input the first reference voltage output by the reference source module to the ADC sampling module through the first switch module, and obtain the first self-test result of the ADC sampling module based on the first ADC sampling voltage output by the ADC sampling module.

2. The circuit breaker with self-testing function according to claim 1, characterized in that, The first switch module includes a first analog switch; The first input terminal of the first analog switch is electrically connected to the reference source module, the second input terminal of the first analog switch is electrically connected to the input terminal of the ADC sampling module, and the controlled terminal of the first analog switch is electrically connected to the first output terminal of the processing module.

3. The circuit breaker with self-testing function according to claim 1, characterized in that, The circuit breaker with self-testing function also includes a second switching module and a signal conditioning module; The reference source module is also electrically connected to the input terminal of the signal conditioning module through the second switch module, the second switch module is also electrically connected to the second output terminal of the processing module, and the output terminal of the signal conditioning module is electrically connected to the input terminal of the ADC sampling module. The processing module is further configured to input the second reference voltage output by the reference source module to the signal conditioning module through the second switch module when the first self-test result indicates that the ADC sampling module is normal, and to obtain the second self-test result of the signal conditioning module based on the second ADC sampling voltage output by the ADC sampling module.

4. The circuit breaker with self-testing function according to claim 3, characterized in that, The second switching module includes a second analog switch; The first input terminal of the second analog switch is electrically connected to the reference source module, the second input terminal of the second analog switch is electrically connected to the input terminal of the signal conditioning module, and the controlled terminal of the second analog switch is electrically connected to the second output terminal of the processing module.

5. The circuit breaker with self-testing function according to claim 3, characterized in that, The circuit breaker with self-test function also includes a current transformer and a first pull-down resistor; The current transformer is electrically connected to the first pull-down resistor and the input terminal of the signal conditioning module, respectively. The processing module is further configured to obtain the third self-test result of the current transformer based on the third ADC sampling voltage output by the ADC sampling module when the second self-test result indicates that the signal conditioning module is normal.

6. The circuit breaker with self-testing function according to claim 1, characterized in that, The circuit breaker with self-testing function also includes a power supply protection module and a power processing module; The input terminal of the power supply protection module is used to connect to the power supply, and the output terminal of the power supply protection module is electrically connected to the input terminal of the power processing module to output protection power. The output terminal of the power processing module is electrically connected to the power supply terminal of the reference source module, the power supply terminal of the first switch module, the power supply terminal of the ADC sampling module, and the power supply terminal of the processing module, respectively. The power supply protection module is used to control the state between its input and output terminals to a target state when the power supply is abnormal, so as to limit the output of the protective power supply.

7. The circuit breaker with self-testing function according to claim 6, characterized in that, The power supply protection module includes an overvoltage protection unit; The input terminal of the overvoltage protection unit is used to connect to the power supply, and the output terminal of the overvoltage protection unit is used to output the protection power supply. The overvoltage protection unit is used to disconnect the line between its input and output terminals when the voltage of the power supply exceeds a preset voltage protection threshold.

8. The circuit breaker with self-testing function according to claim 7, characterized in that, The overvoltage protection unit includes a PMOS transistor, a first PNP transistor, a second pull-down resistor, a first voltage divider resistor, and a second voltage divider resistor; The source of the PMOS transistor, the emitter of the first PNP transistor, and the first terminal of the first voltage divider resistor are respectively used to connect to the power supply. The second terminal of the first voltage divider resistor is electrically connected to the base of the first PNP transistor and the first terminal of the second voltage divider resistor. The collector of the first PNP transistor is electrically connected to the gate of the PMOS transistor and the first terminal of the second pull-down resistor. The drain of the PMOS transistor is used to output the protection power supply. The second terminal of the second voltage divider resistor and the second terminal of the second pull-down resistor are respectively used to ground.

9. The circuit breaker with self-testing function according to claim 6, characterized in that, The power supply protection module includes an overcurrent protection unit; The input terminal of the overcurrent protection unit is used to connect to the power supply, and the output terminal of the overcurrent protection unit is used to output the protection power supply. The overcurrent protection unit is used to increase the impedance between its input and output terminals when the current in the line between its input and output terminals exceeds a preset current protection threshold.

10. The circuit breaker with self-testing function according to claim 9, characterized in that, The overcurrent protection unit includes a PMOS transistor, a second PNP transistor, a second pull-down resistor, and a voltage drop resistor; The source of the PMOS transistor is electrically connected to the first terminal of the voltage drop resistor and the base of the second PNP transistor, respectively. The second terminal of the voltage drop resistor and the emitter of the second PNP transistor are respectively used to connect to the power supply. The collector of the second PNP transistor is electrically connected to the gate of the PMOS transistor and the first terminal of the second pull-down resistor, respectively. The drain of the PMOS transistor is used to output the protection power supply, and the second terminal of the second pull-down resistor is used to ground.

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