Sampling circuit and circuit breaker

Abstract

The utility model discloses a sampling circuit and a circuit breaker. The sampling circuit comprises a reference source module, a voltage sampling module and a frequency sampling module. The reference source module is connected with a first power supply voltage, and the reference source module is configured to convert the first power supply voltage into a reference voltage; the voltage sampling module is connected with a sampled circuit, the voltage sampling module is connected with the reference source module, and the voltage sampling module is configured to convert output voltage of each phase of the sampled circuit and output sampling voltage corresponding to the output voltage of each phase; the frequency sampling module is respectively connected with the voltage sampling module and the reference source module, and the frequency sampling module is configured to output a pulse signal with the same frequency as the sampling voltage based on a comparison result of each sampling voltage and the reference voltage; wherein a part of devices in the reference source module and a part of devices in the frequency sampling module are integrated on the same chip. The sampling circuit provided by the utility model is small in size, and facilitates the design of a protection circuit in a miniature circuit breaker product.

Description

TECHNICAL FIELD

[0001] The utility model relates to sampling technical field especially, relate to a sampling circuit and circuit breaker. BACKGROUND

[0002] Miniature circuit breaker and other micro -off products and plastic -shell circuit breaker and other plastic -shell products need to carry out the protection of islanding prevention. The protection of islanding prevention is an important power system protection mechanism, can prevent the power generation system (for example photovoltaic grid -connected power generation system) in islanding operation state, thereby avoiding the uncontrolled voltage and frequency on the island to user, equipment and maintenance personnel cause damage. Among them, voltage detection and frequency detection are important for realizing the protection function of islanding prevention.

[0003] But the existing voltage detection and frequency detection circuit are complex, and the volume is big, is not favorable to the design of protection circuit in micro -off product. UTILITY MODEL CONTENTS

[0004] The utility model provides a kind of sampling circuit and circuit breaker, to solve the problem of the existing voltage detection and frequency detection circuit are complex, and the volume is big.

[0005] According to an aspect of the utility model, a kind of sampling circuit is provided, and the sampling circuit includes: reference source module, voltage sampling module and frequency sampling module;

[0006] The reference source module is connected with first power supply voltage, and the reference source module is configured to convert the first power supply voltage into reference voltage;

[0007] The voltage sampling module is connected with the circuit to be sampled, and the voltage sampling module is connected with the reference source module, and the voltage sampling module is configured to convert each phase output voltage of the circuit to be sampled, and output the sampling voltage corresponding to each phase output voltage;

[0008] The frequency sampling module is connected with the voltage sampling module and the reference source module respectively, and the frequency sampling module is configured to output the pulse signal of the same frequency with the sampling voltage based on the comparison result of each sampling voltage and the reference voltage;

[0009] Among them, part of the device in the reference source module and part of the device in the frequency sampling module are integrated on the same chip.

[0010] Optionally, the reference source module includes voltage follower unit and first voltage division unit;

[0011] The first end of the first voltage division unit is connected with the first power supply voltage, and the second end of the first voltage division unit is connected with second power supply voltage;

[0012] The first input end of the voltage follower unit is connected with the output end of the first voltage dividing unit, the second input end of the voltage follower unit is connected with the output end of the voltage follower unit, and the output end of the voltage follower unit outputs the reference voltage.

[0013] Optionally, the frequency sampling module comprises at least one comparison unit.

[0014] The first input end of the comparison unit is connected with the voltage sampling module, the second input end of the comparison unit is connected with the output end of the reference source module, and the comparison unit is configured to output a pulse signal of a first level when the sampling voltage is greater than the reference voltage, and output a pulse signal of a second level when the sampling voltage is less than or equal to the reference voltage.

[0015] Optionally, the voltage follower unit comprises a first operational amplifier.

[0016] The first input end of the first operational amplifier is connected with the output end of the first voltage dividing unit, the second input end of the first operational amplifier is connected with the output end of the first operational amplifier, and the output end of the first operational amplifier outputs the reference voltage.

[0017] The comparison unit comprises a second operational amplifier.

[0018] The first input end of the second operational amplifier is connected with the voltage sampling module, the second input end of the second operational amplifier is connected with the output end of the reference source module, and the output end of the second operational amplifier outputs the pulse signal.

[0019] The first operational amplifier and all the second operational amplifiers are integrated on the same chip.

[0020] Optionally, the voltage sampling module comprises at least one second voltage dividing unit, and the number of the second voltage dividing units is the same as the number of phases of the output voltage of the sampled circuit.

[0021] The first end of the second voltage dividing unit is connected with the output end of the sampled circuit, the second end of the second voltage dividing unit is connected with the output end of the reference source module, and the third end of the second voltage dividing unit outputs the sampling voltage corresponding to the output voltage of the sampled circuit.

[0022] Optionally, the second voltage dividing unit comprises at least one first resistor and a first capacitor.

[0023] At least one first resistor is connected in series between the output end of the sampled circuit and the frequency sampling module.

[0024] The first end of the first capacitor is connected with the frequency sampling module, and the second end of the first capacitor is connected with the output end of the reference source module.

[0025] Optionally, the first voltage dividing unit comprises a second resistor and a third resistor.

[0026] The first end of the second resistor is connected with the first power supply voltage, the second end of the second resistor is connected with the first end of the third resistor, and the second end of the third resistor is connected with the second power supply voltage; wherein the second end of the second resistor is the output end of the first voltage dividing unit.

[0027] Optionally, the reference source module further comprises a second capacitor.

[0028] The first end of the second capacitor is connected with the output end of the voltage follower unit, and the second end of the second capacitor is connected with the second power supply voltage.

[0029] The reference source module further comprises a fourth resistor and a voltage stabilizing diode.

[0030] The first end of the second resistor is connected with the first power supply voltage through the fourth resistor, the second end of the second resistor is connected with the first end of the voltage stabilizing diode, the second end of the voltage stabilizing diode is connected with the second end of the voltage stabilizing diode, and the third end of the voltage stabilizing diode is connected with the second power supply voltage.

[0031] Optionally, the sampling circuit further comprises a third capacitor and a fourth capacitor.

[0032] The first power supply end of the first operational amplifier or any second operational amplifier is connected with the first end of the third capacitor, and the second end of the third capacitor is connected with the second power supply voltage.

[0033] The first end of the fourth capacitor is connected with the first end of the third capacitor, and the second end of the fourth capacitor is connected with the second end of the third capacitor.

[0034] The first end of the third capacitor is connected with the first power supply voltage.

[0035] The second power supply end of the first operational amplifier or any second operational amplifier is connected with the second power supply voltage.

[0036] Optionally, the sampling circuit further comprises a processing module.

[0037] The processing module is connected with the voltage sampling module and the frequency sampling module respectively, and the processing module is configured to determine the output voltage according to the sampling voltage and determine the frequency of the output voltage according to the frequency of the pulse signal.

[0038] According to another aspect of the utility model, a kind of circuit breaker is provided, and the circuit breaker includes the sampling circuit described in any embodiment of the utility model.

[0039] The technical scheme of the utility model embodiment, the voltage sampling module converts each phase output voltage of the sampled circuit, and outputs the sampling voltage corresponding to each phase output voltage;The frequency sampling module outputs the pulse signal of the same frequency as the sampling voltage based on the comparison result of each sampling voltage and reference voltage, so as to facilitate the determination of the amplitude and frequency of the sampling voltage, and then the amplitude and frequency of each phase output voltage of the sampled circuit are determined, the sampling circuit is not too complex, and it is beneficial to the design of protection circuit in micro-break type product.And, part of the devices of reference source module and part of the devices in frequency sampling module are integrated on the same chip, which can improve the integration of the sampling circuit, thereby reducing the size of the sampling circuit, which is beneficial to the design of protection circuit in micro-break type product.

[0040] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the utility model, nor is it used to limit the scope of the utility model. Other features of the utility model will become easily understood through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical scheme in the embodiments of the utility model, the drawings needed in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0042] Figure 1 It is a structure schematic view of the sampling circuit provided by the utility model embodiment;

[0043] Figure 2 It is another structure schematic view of the sampling circuit provided by the utility model embodiment;

[0044] Figure 3 It is another structure schematic view of the sampling circuit provided by the utility model embodiment. DETAILED DESCRIPTION

[0045] In order to make those skilled in the art better understand the utility model scheme, the technical scheme in the utility model embodiments will be described clearly and completely below in conjunction with the drawings in the utility model embodiments, obviously, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the utility model.

[0046] It should be noted that the terms "first", "second", etc. in the description and claims of the present application and in the above drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] The embodiment provides a sampling circuit, which can be applied to a protection circuit, a monitoring circuit or the like, and is not limited by the embodiment. The sampling circuit can collect the voltage and frequency of an electric signal. Figure 1 is a structural schematic diagram of a sampling circuit provided by the embodiment of the present application, referring to Figure 1 The sampling circuit comprises a reference source module 110, a voltage sampling module 120 and a frequency sampling module 130.

[0048] The reference source module 110 is connected with a first power supply voltage VDD, and is configured to convert the first power supply voltage VDD into a reference voltage Vref.

[0049] The voltage sampling module 120 is connected with a sampled circuit, and is connected with the reference source module 110. The voltage sampling module 120 is configured to convert each-phase output voltage of the sampled circuit, and output a sampling voltage corresponding to each-phase output voltage.

[0050] The frequency sampling module 130 is connected with the voltage sampling module 120 and the reference source module 110 respectively. The frequency sampling module 130 is configured to output a pulse signal with the same frequency as the sampling voltage based on the comparison result of each sampling voltage and the reference voltage Vref.

[0051] Part of the devices in the reference source module 110 and part of the devices in the frequency sampling module 130 are integrated on the same chip.

[0052] The first power supply voltage VDD is a positive voltage, which can be a 3.3V positive voltage, or a 12V or 5V positive voltage, and the embodiment is not limited in this regard. The reference source module 110 can include a direct current conversion circuit, a voltage stabilizing circuit, a voltage boosting circuit, or a voltage dividing circuit, so that the first power supply voltage VDD can be converted to output a reference voltage Vref. The voltage sampling module 120 is connected to the sampled circuit, for example, connected to the output end of the sampled circuit. The sampled circuit can be an output circuit of a power generation system, and can output a single-phase voltage, a two-phase voltage, or a multi-phase voltage. For example, the sampled circuit outputs a three-phase voltage, the voltage sampling module 120 is connected to a first output end A of the sampled circuit to access a first phase voltage, connected to a second output end B of the sampled circuit to access a second phase voltage, and connected to a third output end C of the sampled circuit to access a third phase voltage. The voltage sampling module 120 can convert each phase output voltage of the sampled circuit, for example, to step down, and then to step up through the reference voltage Vref to output a sampling voltage corresponding to each phase output voltage, for example, to output a first sampling voltage UA corresponding to a first phase output voltage, a second sampling voltage UB corresponding to a second phase output voltage, and a third sampling voltage UC corresponding to a third phase output voltage. For example, the output voltage of the sampled circuit is a sinusoidal voltage, and the sampling voltage output by the voltage sampling module 120 is also a sinusoidal voltage.

[0053] Specifically, the frequency sampling module 130 can compare each sampling voltage with the reference voltage Vref to output a pulse signal, and the frequency of the pulse signal is the same as that of the sampling voltage, so that the frequency of the sampling voltage can be determined by the frequency of the pulse signal. The sampling voltage output by the voltage sampling module 120 can be transmitted to the processing module, and the processing module can determine the output voltage of the sampled circuit according to the sampling voltage to detect the output voltage of the sampled circuit. The pulse signal output by the frequency sampling module 130 can be transmitted to the processing module, and the processing module can determine the frequency of the sampling voltage according to the frequency of the pulse signal, i.e., determine the frequency of the output voltage of the sampled circuit. For example, the sampled circuit outputs a three-phase voltage, the frequency sampling module 130 outputs a first pulse signal FA_HZ corresponding to the first phase output voltage, a second pulse signal FB_HZ corresponding to the first phase output voltage, and a third pulse signal FC_HZ corresponding to the first phase output voltage, so as to obtain the frequency of each phase output voltage.

[0054] In this way, the voltage sampling module 120 outputs the sampling voltage corresponding to each phase output voltage of the sampled circuit, and the frequency sampling module 130 outputs the pulse signal corresponding to the sampling voltage, which can facilitate the determination of the amplitude and frequency of the sampling voltage, and further the determination of the amplitude and frequency of each phase output voltage of the sampled circuit. The sampling circuit is not too complex, which is conducive to the design of the protection circuit in the micro-break product.

[0055] And, part of the device in the reference source module 110 and part of the device in the frequency sampling module 130 are integrated on the same chip, for example, the device for voltage conversion or voltage following in the reference source module 110 and the device for comparing the sampling voltage with the reference voltage Vref in the frequency sampling module 130 are integrated on the same chip, that is, the device for voltage conversion or voltage following in the reference source module 110 and the device for comparing the sampling voltage with the reference voltage Vref in the frequency sampling module 130 can be different parts of the same chip. In this way, the integration of the sampling circuit can be improved, thereby reducing the size of the sampling circuit, which is beneficial to the design of the protection circuit in the micro-break product.

[0056] It should be noted that, Figure 1 The case that the three-phase output voltage output by the sampled circuit is shown in the figure, but it is not limited thereto.

[0057] The technical scheme of the embodiment, the voltage sampling module converts each phase output voltage of the sampled circuit and outputs the sampling voltage corresponding to each phase output voltage; the frequency sampling module outputs the pulse signal with the same frequency as the sampling voltage based on the comparison result of each sampling voltage and the reference voltage, so as to facilitate the determination of the amplitude and frequency of the sampling voltage, and further the determination of the amplitude and frequency of each phase output voltage of the sampled circuit, the sampling circuit is not too complex, which is beneficial to the design of the protection circuit in the micro-break product. And, part of the device in the reference source module and part of the device in the frequency sampling module are integrated on the same chip, which can improve the integration of the sampling circuit, thereby reducing the size of the sampling circuit, which is beneficial to the design of the protection circuit in the micro-break product.

[0058] On the basis of the above technical scheme, Figure 2 It is another structure diagram of the sampling circuit provided by the embodiment of the utility model, optionally, reference Figure 2 The reference source module 110 includes a voltage following unit 111 and a first voltage dividing unit 112.

[0059] The first end of the first voltage dividing unit 112 is connected to the first power supply voltage VDD, and the second end of the first voltage dividing unit 112 is connected to the second power supply voltage VSS.

[0060] The first input end of the voltage following unit 111 is connected to the output end of the first voltage dividing unit 112, the second input end of the voltage following unit 111 is connected to the output end of the voltage following unit 111, and the output end of the voltage following unit 111 outputs the reference voltage Vref.

[0061] Among them, the second power supply voltage VSS can be a negative voltage, or a zero voltage, that is, a ground, and the embodiment does not limit it.

[0062] Specifically, the first voltage dividing unit 112 can divide the first power supply voltage VDD, so as to divide the first power supply voltage VDD to obtain the reference voltage Vref. The voltage follower unit 111 can realize voltage following, so as to ensure that the output voltage is the same as the reference voltage Vref output by the first voltage dividing unit 112, thereby ensuring the accuracy of the output reference voltage Vref.

[0063] Optionally, with reference to Figure 2 The frequency sampling module 130 includes at least one comparison unit 131.

[0064] The first input end of the comparison unit 131 is connected with the voltage sampling module 120, the second input end of the comparison unit 131 is connected with the output end of the reference source module 110, and the comparison unit 131 is configured to output a pulse signal of a first level when the sampling voltage is greater than the reference voltage Vref, and output a pulse signal of a second level when the sampling voltage is less than or equal to the reference voltage.

[0065] The first level is a high level and the second level is a low level, or the first level is a low level and the second level is a high level, which is not limited in the embodiment. The number of comparison units 131 is the same as the number of voltages output by the sampled circuit, so as to sample the frequency of each phase voltage. When the sampled circuit outputs three-phase voltage, the frequency sampling module 130 includes three comparison units 131.

[0066] Specifically, the comparison unit 131 can compare each sampling voltage with the reference voltage Vref, output a pulse signal of a first level when the sampling voltage is greater than the reference voltage Vref, and output a pulse signal of a second level when the sampling voltage is less than or equal to the reference voltage, so as to output a pulse signal with the same frequency as the sampling voltage, thereby facilitating determination of the frequency of the sampling voltage, i.e. the frequency of the output voltage of the sampled circuit, according to the pulse signal.

[0067] Optionally, with reference to Figure 2 The voltage follower unit 111 includes a first operational amplifier U1D.

[0068] The first input end of the first operational amplifier U1D is connected with the output end of the first voltage dividing unit 112, the second input end of the first operational amplifier U1D is connected with the output end of the first operational amplifier U1D, and the output end of the first operational amplifier U1D outputs the reference voltage Vref.

[0069] The comparison unit 131 includes a second operational amplifier.

[0070] The first input end of the second operational amplifier is connected with the voltage sampling module 120, the second input end of the second operational amplifier is connected with the output end of the reference source module 110, and the output end of the second operational amplifier outputs the pulse signal.

[0071] The first operational amplifier U1D and all the second operational amplifiers are integrated on the same chip.

[0072] For example, the three-phase voltage output by the sampled circuit, the frequency sampling module 130 includes three comparison units 131, that is, three second operational amplifiers, for example, the first second operational amplifier U1A, the second second operational amplifier U1B and the third second operational amplifier U1C.

[0073] Specifically, the first input end of the first operational amplifier U1D is connected with the output end of the first voltage dividing unit 112, the second input end of the first operational amplifier U1D is connected with the output end of the first operational amplifier U1D, and the amplification factor of the first operational amplifier U1D is 1, so that the voltage output by the first operational amplifier U1D is the reference voltage Vref output by the first voltage dividing unit 112, realizing voltage following.

[0074] The second operational amplifier can compare the input sampled voltage with the reference voltage Vref to realize the function of a comparator, so as to output a pulse signal including a first level and a second level according to the comparison result of the sampled voltage and the reference voltage Vref.

[0075] By integrating the first operational amplifier U1D and all the second operational amplifiers in the same operational amplifier, the integration degree of the sampling circuit can be improved, so as to reduce the volume of the sampling circuit, and facilitate the realization of the protection circuit in the micro-break product.

[0076] The first input end of the first operational amplifier U1D can be a non-inverting input end, and the second input end of the first operational amplifier U1D is an inverting input end. The first input end of the second operational amplifier is an inverting input end, and the second input end of the second operational amplifier is a non-inverting input end; in other some embodiments, the first input end of the second operational amplifier can be a non-inverting input end, and the second input end of the second operational amplifier is an inverting input end, which is not limited in the embodiment.

[0077] Optionally, with reference to Figure 2 The voltage sampling module 120 includes at least one second voltage dividing unit 121; the number of the second voltage dividing units 121 is the same as the number of phases of the output voltage of the sampled circuit;

[0078] The first end of the second voltage dividing unit 121 is connected with the output end of the sampled circuit, the second end of the second voltage dividing unit is connected with the output end of the reference source module 110, and the third end of the second voltage dividing unit 121 outputs a sampled voltage corresponding to the output voltage of the sampled circuit.

[0079] Specifically, the second voltage dividing unit 121 can divide the output voltage of the sampled circuit, so as to convert into a sampling voltage, so that the sampling voltage is small, facilitating input to the processing module, so that the processing module can determine the output voltage of the sampled circuit according to the sampling voltage and the voltage dividing parameter of the second voltage dividing unit 121.

[0080] Optionally, referring to Figure 2 , the second voltage dividing unit 121 includes at least one first resistor R1 and a first capacitor C1.

[0081] The at least one first resistor R1 is connected in series between the output end of the sampled circuit and the frequency sampling module 130.

[0082] The first end of the first capacitor C1 is connected with the frequency sampling module 130, and the second end of the first capacitor C1 is connected with the output end of the reference source module 110.

[0083] Specifically, by arranging the at least one first resistor R1, the output voltage of the sampled circuit can be divided, facilitating obtaining the sampling voltage. The number and resistance value of the first resistor R1 can be determined according to the amplitude of the sampling voltage that the processing module can withstand, and the embodiment is not limited. The resistance values of different first resistors R1 can be the same or different, which is not limited here. By arranging the first capacitor C1, the sampling voltage can be filtered, and the accuracy of the sampling voltage output by the voltage sampling module 120 is improved.

[0084] It should be noted that Figure 2 The second voltage dividing unit 121 includes five first resistors R1, but is not limited.

[0085] Optionally, referring to Figure 2 , the first voltage dividing unit 112 includes a second resistor R2 and a third resistor R3.

[0086] The first end of the second resistor R2 is connected to the first power supply voltage VDD, the second end of the second resistor R2 is connected with the first end of the third resistor R3, and the second end of the third resistor R3 is connected to the second power supply voltage VSS. The second end of the second resistor R2 is the output end of the first voltage dividing unit 112.

[0087] Specifically, by arranging the second resistor R2 and the third resistor R3, the first power supply voltage VDD can be divided, so as to convert into a reference voltage Vref. The resistance values of the second resistor R2 and the third resistor R3 can be determined according to the amplitude of the reference voltage Vref and the first power supply voltage VDD, and the embodiment is not limited.

[0088] Optionally, referring to Figure 2 , the reference source module 110 further includes a second capacitor C2.

[0089] The first end of the second capacitor C2 is connected with the output end of the voltage follower unit 111, and the second end of the second capacitor C2 is connected with the second power supply voltage VSS;

[0090] The reference source module 110 further comprises a fourth resistor R4 and a voltage stabilizing diode D1;

[0091] The first end of the second resistor R2 is connected with the first power supply voltage VDD through the fourth resistor R4, the second end of the second resistor R2 is connected with the first end of the voltage stabilizing diode D1, the second end of the voltage stabilizing diode D1 is connected with the second end of the voltage stabilizing diode D1, and the third end of the voltage stabilizing diode D1 is connected with the second power supply voltage VSS.

[0092] Specifically, by setting the second capacitor C2, filtering can be performed to ensure the stability and accuracy of the output reference voltage Vref, thereby improving the accuracy of the pulse signal output by the frequency sampling module 130 and improving the accuracy of the sampling circuit. By setting the fourth resistor R4, current limiting and voltage division can be performed. By setting the voltage stabilizing diode D1, the voltage input by the first voltage division unit 112 can be stabilized, so that the reference voltage Vref output by the first voltage division unit 112 is stable, thereby ensuring the stability and reliability of the reference voltage Vref output by the reference source module 110.

[0093] Optionally, with reference Figure 2 to the sampling circuit further comprises a third capacitor C3 and a fourth capacitor C4;

[0094] The first power supply end of the first operational amplifier U1D or any second operational amplifier is connected with the first end of the third capacitor C3, and the second end of the third capacitor C3 is connected with the second power supply voltage VSS;

[0095] The first end of the fourth capacitor C4 is connected with the first end of the third capacitor C3, and the second end of the fourth capacitor C4 is connected with the second end of the third capacitor C3;

[0096] The first end of the third capacitor C3 is connected with the first power supply voltage VDD;

[0097] The second power supply end of the first operational amplifier U1D or any second operational amplifier is connected with the second power supply voltage VSS.

[0098] Specifically, by setting the third capacitor C3 and the fourth capacitor C4, the first power voltage VDD can be filtered, so that the first operational amplifier U1D and all the second operational amplifier integrated operational amplifiers can be better powered. By integrating the first operational amplifier U1D and all the second operational amplifiers into one operational amplifier, only the first operational amplifier U1D or any second operational amplifier can be connected to the first power voltage VDD and the second power voltage VSS, that is, the power supply of the entire operational amplifier can be realized, thereby saving space and further reducing the size of the sampling circuit.

[0099] On the basis of the above technical solutions, Figure 3 is a structure diagram of another sampling circuit provided by the embodiment of the utility model, optionally, referring to Figure 3 The sampling circuit further comprises a processing module 140.

[0100] The processing module 140 is connected with the voltage sampling module 120 and the frequency sampling module 130 respectively, and the processing module 140 is configured to determine an output voltage according to a sampling voltage and determine a frequency of the output voltage according to a frequency of the pulse signal.

[0101] Specifically, the processing module 140 can include a single-chip microcomputer, a microcontroller or a field programmable gate array (FPGA) and the like. The processing module 140 can determine the amplitude of the output voltage of the corresponding sampled circuit according to the sampling voltage and the resistance value of at least one first resistor R1 in the second voltage dividing unit 121. The processing module 140 can determine the frequency of the output voltage of the corresponding sampled circuit according to the pulse signal. In this way, the sampling of voltage and frequency is realized.

[0102] The utility model further provides a circuit breaker, the circuit breaker includes the sampling circuit provided by any implementation scheme, therefore the circuit breaker has the same beneficial effect with the sampling circuit provided by any implementation scheme, and does not repeat here.

[0103] The above specific embodiments do not constitute a limitation on the protection scope of the utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A sampling circuit, characterized by, The application relates to a voltage and frequency sampling module. The application comprises a reference source module, a voltage sampling module and a frequency sampling module. The reference source module is connected to a first power supply voltage, and is configured to convert the first power supply voltage into a reference voltage. The voltage sampling module is connected to a sampled circuit and the reference source module, and is configured to convert each phase output voltage of the sampled circuit into a corresponding sampling voltage. The frequency sampling module is connected to the voltage sampling module and the reference source module, and is configured to output a pulse signal with the same frequency as the sampling voltage based on the comparison result of each sampling voltage and the reference voltage. Part of the devices in the reference source module and part of the devices in the frequency sampling module are integrated on the same chip.

2. The sampling circuit of claim 1, wherein, The reference source module comprises a voltage follower unit and a first voltage dividing unit. The first end of the first voltage dividing unit is connected to the first power supply voltage, and the second end of the first voltage dividing unit is connected to a second power supply voltage. The first input end of the voltage follower unit is connected to the output end of the first voltage dividing unit, the second input end of the voltage follower unit is connected to the output end of the voltage follower unit, and the output end of the voltage follower unit outputs the reference voltage.

3. The sampling circuit of claim 2, wherein, The frequency sampling module comprises at least one comparison unit. The first input end of the comparison unit is connected to the voltage sampling module, the second input end of the comparison unit is connected to the output end of the reference source module, and the comparison unit is configured to output a pulse signal with a first level when the sampling voltage is greater than the reference voltage, and output a pulse signal with a second level when the sampling voltage is less than or equal to the reference voltage.

4. The sampling circuit of claim 3, wherein, The voltage follower unit comprises a first operational amplifier. The first input end of the first operational amplifier is connected to the output end of the first voltage dividing unit, the second input end of the first operational amplifier is connected to the output end of the first operational amplifier, and the output end of the first operational amplifier outputs the reference voltage. The comparison unit comprises a second operational amplifier. The first input end of the second operational amplifier is connected to the voltage sampling module, the second input end of the second operational amplifier is connected to the output end of the reference source module, and the output end of the second operational amplifier outputs the pulse signal. The first operational amplifier and all the second operational amplifiers are integrated on the same chip.

5. The sampling circuit of claim 1, wherein, The voltage sampling module comprises at least one second voltage dividing unit, and the number of the second voltage dividing units is the same as the number of the phases of the output voltage of the sampled circuit. The first end of the second voltage dividing unit is connected to the output end of the sampled circuit, the second end of the second voltage dividing unit is connected to the output end of the reference source module, and the third end of the second voltage dividing unit outputs the sampling voltage corresponding to the output voltage of the sampled circuit.

6. The sampling circuit of claim 5, wherein, The second voltage dividing unit comprises at least one first resistor and a first capacitor. At least one first resistor is connected in series between the output end of the sampled circuit and the frequency sampling module. The first end of the first capacitor is connected with the frequency sampling module, and the second end of the first capacitor is connected with the output end of the reference source module.

7. The sampling circuit of claim 2, wherein, The first voltage dividing unit comprises a second resistor and a third resistor. The first end of the second resistor is connected with the first power supply voltage, the second end of the second resistor is connected with the first end of the third resistor, and the second end of the third resistor is connected with the second power supply voltage; wherein the second end of the second resistor is the output end of the first voltage dividing unit.

8. The sampling circuit of claim 7, wherein, The reference source module further comprises a second capacitor. The first end of the second capacitor is connected with the output end of the voltage follower unit, and the second end of the second capacitor is connected with the second power supply voltage. The reference source module further comprises a fourth resistor and a voltage stabilizing diode. The first end of the second resistor is connected with the first power supply voltage through the fourth resistor, the second end of the second resistor is connected with the first end of the voltage stabilizing diode, the second end of the voltage stabilizing diode is connected with the second end of the voltage stabilizing diode, and the third end of the voltage stabilizing diode is connected with the second power supply voltage.

9. The sampling circuit of claim 4, wherein, The sampling circuit further comprises a third capacitor and a fourth capacitor. The first power supply end of the first operational amplifier or any one of the second operational amplifiers is connected with the first end of the third capacitor, and the second end of the third capacitor is connected with the second power supply voltage. The first end of the fourth capacitor is connected with the first end of the third capacitor, and the second end of the fourth capacitor is connected with the second end of the third capacitor. The first end of the third capacitor is connected with the first power supply voltage. The second power supply end of the first operational amplifier or any one of the second operational amplifiers is connected with the second power supply voltage.

10. The sampling circuit of claim 1, wherein, The sampling circuit further comprises a processing module. The processing module is connected with the voltage sampling module and the frequency sampling module respectively, and the processing module is configured to determine the output voltage according to the sampling voltage and determine the frequency of the output voltage according to the frequency of the pulse signal.

11. A circuit breaker characterized by, The sampling circuit comprises any one of claims 1-10. The sampling circuit comprises any one of claims 1-10.

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