CN117452058A - Current sampling circuit and device thereof - Google Patents

Current sampling circuit and device thereof Download PDF

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Publication number
CN117452058A
CN117452058A CN202311653635.7A CN202311653635A CN117452058A CN 117452058 A CN117452058 A CN 117452058A CN 202311653635 A CN202311653635 A CN 202311653635A CN 117452058 A CN117452058 A CN 117452058A
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China
Prior art keywords
capacitor
resistor
voltage
terminal
module
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CN202311653635.7A
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Inventor
赵福元
蒋中明
杨益
粟金雨
罗来明
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Hunan Megmit Electric Technology Co ltd
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Hunan Megmit Electric Technology Co ltd
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Priority to CN202311653635.7A priority Critical patent/CN117452058A/en
Publication of CN117452058A publication Critical patent/CN117452058A/en
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
    • G01R1/28—Provision in measuring instruments for reference values, e.g. standard voltage, standard waveform
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
    • G01R1/30—Structural combination of electric measuring instruments with basic electronic circuits, e.g. with amplifier
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/14—Adaptations providing voltage or current isolation, e.g. for high-voltage or high-current networks
    • G01R15/146—Measuring arrangements for current not covered by other subgroups of G01R15/14, e.g. using current dividers, shunts, or measuring a voltage drop

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Current Or Voltage (AREA)

Abstract

The embodiment of the invention discloses a current sampling circuit and a device thereof, wherein the circuit comprises: a shunt module for collecting and converting the high voltage electrical signal into a first voltage signal and a second voltage signal; the first amplifying module is used for carrying out isolation amplification on the first voltage signal and the second voltage signal and outputting a first isolation signal and a second isolation signal; the second amplifying module is used for carrying out differential proportional amplification on the first isolation signal and the second isolation signal and outputting a conversion voltage; and the control module is used for calculating a high-voltage current signal according to the conversion voltage. The high-voltage current signal is converted into two paths of low-voltage signals through the current divider, the first amplifying module and the second amplifying module conduct isolation amplification and proportional operation amplification on the two paths of voltage signals, and finally the control module calculates according to the voltage signals to obtain the high-voltage current signal.

Description

Current sampling circuit and device thereof
Technical Field
The embodiment of the invention relates to the technical field of electronic circuits, in particular to a current sampling circuit and a device thereof.
Background
A battery energy storage system is a device that uses a battery for energy storage and release. With the increase in energy demand and the popularization of renewable energy sources, battery energy storage systems play an increasingly important role in the energy field. The working principle of the battery energy storage system is based on the charge and discharge process of the battery. When the system needs to store energy, the battery is charged from an external power source, converting the electrical energy into chemical energy for release at a future time of use. When the system needs energy, the battery can convert the stored chemical energy into electric energy through the reverse process to be used by a load. This process may be cycled to achieve continuous storage and supply of energy.
The current sampling in the battery energy storage system is a very important index, and the current application circuit applied to the battery energy storage system at present has the defects of low full-range sampling precision, high cost and low reliability, so that the whole battery energy storage management system is inaccurate in metering and unstable in control.
Disclosure of Invention
The technical problem which is mainly solved by the embodiment of the invention is to provide a current sampling circuit and a device thereof, which can be applied to current sampling of a battery energy storage system, improve the sampling precision of the whole measuring range, reduce the cost of the current sampling circuit and improve the reliability.
In order to solve the technical problems, one technical scheme adopted by the embodiment of the invention is as follows: there is provided a current sampling circuit including: a shunt module for collecting and converting the high voltage electrical signal into a first voltage signal and a second voltage signal; the first amplifying module is used for carrying out isolation amplification on the first voltage signal and the second voltage signal and outputting a first isolation signal and a second isolation signal; the second amplifying module is used for carrying out differential proportional amplification on the first isolation signal and the second isolation signal and outputting conversion voltage; a control module for calculating the high voltage current signal from the converted voltage; the first output end and the second output end of the current divider module are respectively connected with the first input end and the second input end of the first amplifying module, the first output end and the second output end of the first amplifying module are respectively connected with the first input end and the second input end of the second amplifying module, and the first output end and the second output end of the second amplifying module are respectively connected with the first input end and the second input end of the control module.
In some embodiments, the current sampling circuit further comprises: and the output end of the reference voltage module is connected to the third input end of the second amplifying module.
In some embodiments, the first amplifying module includes a differential isolation amplifier chip U1, a resistor R2, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, and a capacitor C5, where a first signal input end of the differential isolation amplifier chip U1 is connected to a first end of the resistor R1, a second end of the resistor R1 is connected to a first output end of the shunt module, a second signal input end of the differential isolation amplifier chip U1 is connected to a first end of the resistor R2, a second end of the resistor R2 is connected to a second output end of the shunt module, the capacitor C3 is connected between the first end of the resistor R1 and the first end of the resistor R2, a first end of the capacitor C4 is connected to a first end of the resistor R2, a first end of the capacitor C5 is connected to a first end of the resistor R1, and a second end of the capacitor C4 is connected to a second ground; the first electric energy input end of the differential isolation amplifier chip U1 is connected with a first voltage source and the first end of the capacitor C1, the second electric energy input end of the differential isolation amplifier chip U1 is connected with a second voltage source and the first end of the capacitor C2, and the second end of the capacitor C1 and the second end of the capacitor C2 are grounded; the first output end of the differential isolation amplifier chip U1 is connected with the first input end of the second amplifying module, and the second output end of the differential isolation amplifier chip U1 is connected with the second input end of the second amplifying module.
In some embodiments, the second amplifying module includes an operational amplifier chip U2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, and a capacitor C10, where the operational amplifier chip U2 includes two paths of operational amplifiers, a power input end of the operational amplifier chip U2 is connected to a second voltage source and a first end of the capacitor C8, and a second end of the capacitor C8 is grounded; the first non-inverting input terminal of the operational amplifier chip U2 is connected to the first terminal of the resistor R6, the first terminal of the resistor R7 and the first terminal of the capacitor C10, the second terminal of the resistor R6 is connected to the second output terminal of the first amplifying module, and the second terminal of the resistor R7 and the second terminal of the capacitor C10 are connected to the second inverting input terminal and the second output terminal of the operational amplifier chip U2; the first inverting input terminal of the operational amplifier chip U2 is connected to the first terminal of the resistor R5, the first terminal of the resistor R4 and the first terminal of the capacitor C7, the second terminal of the resistor R5 is connected to the first output terminal of the first amplifying module, the second terminal of the resistor R4 is connected to the second terminal of the capacitor C7, the first terminal of the resistor R3 and the first output terminal of the operational amplifier chip U2, the second terminal of the resistor R3 is connected to the first terminal of the capacitor C6 and the input terminal of the control module, and the second terminal of the capacitor C6 is grounded; the second non-inverting input terminal of the operational amplifier chip U2 is connected to the first terminal of the capacitor C9 and the output terminal of the reference voltage module, and the second terminal of the capacitor C9 is grounded.
In some embodiments, the reference voltage module includes a voltage reference chip U3, a resistor R8, a resistor R9, a capacitor C11, and a capacitor C12, where an input end of the voltage reference chip U3 is connected to the first end of the capacitor C11 and the third voltage source, an output end of the voltage reference chip U3 is connected to the first end of the capacitor C12 and the first end of the resistor R8, a second end of the resistor R8 is connected to the third input end of the second amplifying module and the first end of the resistor R9, and a second end of the resistor R9, a second end of the capacitor C11, a second end of the capacitor C12, and a ground of the voltage reference chip U3 are grounded.
In some embodiments, the reference voltage is 1.65V.
In some embodiments, the differential isolation amplifier chip U1 has a fixed gain of 8.
In some embodiments, the output voltage of the first voltage source is 5V, the output voltage of the second voltage source is 3.3V, and the output voltage of the third voltage source is 5V.
In some embodiments, the control module includes a single-chip microcomputer and a hall current sensor, the hall current sensor is used for collecting a conversion current generated by the conversion voltage, and the single-chip microcomputer is used for calculating the high-voltage current signal according to the conversion current.
In order to solve the technical problems, another technical scheme adopted by the embodiment of the invention is as follows: there is provided a current sampling apparatus including: a current sampling circuit as described above.
The beneficial effects of the embodiment of the invention are as follows: compared with the prior art, the embodiment of the invention converts the high-voltage current signal into two paths of low-voltage signals through the current divider, the first amplifying module and the second amplifying module carry out isolation amplification and proportional operation amplification on the two paths of voltage signals, and finally the control module calculates according to the voltage signals to obtain the high-voltage current signal, so that the premise of ensuring the sampling precision, the multi-range premise can be realized, the anti-interference performance and the reliability are improved, and the bidirectional positive/negative current sampling can be realized at the same time.
Drawings
Fig. 1 is a schematic diagram of a current sampling circuit according to an embodiment of the present invention;
fig. 2 is a circuit configuration diagram of a first amplifying module according to an embodiment of the present invention;
fig. 3 is a circuit configuration diagram of a second amplifying module according to an embodiment of the present invention;
fig. 4 is a circuit configuration diagram of a reference voltage module according to an embodiment of the present invention; .
Detailed Description
In order to facilitate an understanding of the present application, the present application will be described in more detail below with reference to the accompanying drawings and specific examples. It will be understood that when an element is referred to as being "fixed" to another element, it can be directly on the other element or one or more intervening elements may be present therebetween. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or one or more intervening elements may be present therebetween. The terms "upper," "lower," "inner," "outer," "bottom," and the like as used in this specification are used in an orientation or positional relationship based on that shown in the drawings, merely to facilitate the description of the present application and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present application. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application in this description is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and/or" as used in this specification includes any and all combinations of one or more of the associated listed items.
In addition, the technical features described below in the different embodiments of the present application may be combined with each other as long as they do not collide with each other.
In the embodiment of the present application, a current sampling circuit is provided, which is applied to a battery energy storage system to sample a high-voltage current signal, and the structural schematic diagram of the current sampling circuit is shown in fig. 1, and the current sampling circuit includes a current divider module 100, a first amplifying module 200, a second amplifying module 300, a control module 400 and a reference voltage module 500.
Wherein a first output end of the current divider module 100 is connected with a first input end of the first amplifying module 200, and a second output end of the current divider module 100 is connected with a second input end of the first amplifying module 200; the first output end of the first amplifying module 200 is connected with the first input end of the second amplifying module 300, and the second output end of the first amplifying module 200 is connected with the second input end of the second amplifying module 300; the first output end of the second amplifying module 300 is connected to the first input end of the control module 400, and the second output end of the second amplifying module 300 is connected to the second input end of the control module 400.
The shunt module 100 is configured to collect a high voltage current signal and convert the high voltage current signal into a first voltage signal and a second voltage signal. In the embodiment of the present application, the specification of the current divider module 100 is 50 mV/250A/0.1%/brass+precision manganese copper, and let the high voltage current signal be I, the converted differential voltage signal Va (i.e. the first voltage signal bas+ and the second voltage signal BAS-) =bas+ -BAS- =50×i/250 mv=0.2×imv. It should be noted that, the two current sampling lines of the current divider module 100 are twisted pair cables with shielding, and the lengths thereof are as short as possible; meanwhile, the splitter module 100 is calibrated in software, so that the anti-interference performance of sampling is enhanced, and the sampling precision is improved.
The first amplifying module 200 is configured to perform isolation amplification on the first voltage signal bas+ and the second voltage signal BAS-, and output a first isolation signal TN and a second isolation signal TP. The magnitudes of the first voltage signal bas+ and the second voltage signal BAS-output by the shunt module 100 are small, and noise current on the common mode high voltage line may interfere with and damage the current sampling signal without isolation. I.e. the first amplification module 200 acts to amplify the first voltage signal BAS + and the second voltage signal BAS-, and to prevent noise currents on the common mode high voltage line from interfering with and damaging the current sampling signal.
The second amplifying module 300 is configured to differentially amplify the first isolation signal TN and the second isolation signal TP, and output a conversion voltage Vc. It should be noted that the second amplifying module 300 includes two operational amplifier circuits, where the first operational amplifier circuit is used for differential proportional amplification of the first isolation signal TN and the second isolation signal TP, and the second operational amplifier circuit is used for voltage following of the reference voltage module 400. Specifically, the reference voltage output by the reference voltage module 400 is output to the input end of the first path of operational amplifier circuit after passing through the second path of operational amplifier circuit voltage, so as to increase the reference voltage of the first path of operational amplifier circuit, and the purpose of measuring the forward/reverse current is to measure the forward/reverse current.
The control module 400 is configured to calculate a high voltage current signal according to the converted voltage Vc, and the reference voltage module 500 is configured to provide a reference voltage for the second amplifying module 300.
In the embodiment of the present application, the reference voltage provided by the reference voltage module 500 is a dc voltage of 1.65V.
In the embodiment of the present application, a specific implementation manner of the first amplifying module 200 is provided, and a circuit structure diagram of the specific implementation manner is shown in fig. 2, where the first amplifying module 200 includes a differential isolation amplifier chip U1, a resistor R2, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, and a capacitor C5.
The first signal input end of the differential isolation amplifier chip U1 is connected to the first end of the resistor R1, the second end of the resistor R1 is connected to the first output end of the shunt module 100, the second signal input end of the differential isolation amplifier chip U1 is connected to the first end of the resistor R2, the second end of the resistor R2 is connected to the second output end of the shunt module 100, the capacitor C3 is connected between the first end of the resistor R1 and the first end of the resistor R2, the first end of the capacitor C4 is connected to the first end of the resistor R2, the first end of the capacitor C5 is connected to the first end of the resistor R1, and the second end of the capacitor C4 is grounded to the second end of the capacitor C5.
The first power input end of the differential isolation amplifier chip U1 is connected with a first voltage source (namely, 5V_HV shown in FIG. 2) and the first end of the capacitor C1, the second power input end of the differential isolation amplifier chip U1 is connected with a second voltage source (namely, 3V3_LV shown in FIG. 2) and the first end of the capacitor C2, and the second end of the capacitor C1 and the second end of the capacitor C2 are grounded; the first output terminal of the differential isolation amplifier chip U1 is connected to the first input terminal of the second amplification module 300 (i.e., the first terminal of the resistor R5 shown in fig. 3), and the second output terminal of the differential isolation amplifier chip U1 is connected to the second input terminal of the second amplification module 300 (i.e., the first terminal of the resistor R6 shown in fig. 3).
In this embodiment, the capacitor C3, the capacitor C4, and the capacitor C5 play a role in isolation filtering, and the capacitor C1 and the capacitor C2 play a role in filtering.
The differential isolation amplifier chip U1 has a differential input voltage range of + -250 mV and low noise of 3.1mV RMS A differential isolation amplifier chip with a fixed gain of 8, a high common mode rejection ratio of 108dB, an isolation voltage of 4250V and a transient immunity of 10kV/us to realize the isolation amplification of the first voltage signal BAS+ and the second voltage signal BAS-. The amplified isolated voltage signal Vb (i.e., the first isolated signal TN and the second isolated signal TP) =tp-tn=8×va=1.6×imv.
The output voltage of the first voltage source 5v_hv is 5V, and the output voltage of the second voltage source 3v3_lv is 3.3V.
In the embodiment of the present application, a specific implementation manner of the second amplifying module 300 is provided, and the circuit structure diagram of the second amplifying module 300 is shown in fig. 3, where the second amplifying module 300 includes an operational amplifier chip U2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, and a capacitor C10.
The operational amplifier chip U2 includes two paths of operational amplifiers, the power input end of the operational amplifier chip U2 is connected to the second voltage source (i.e. 3v3_lv shown in fig. 3) and the first end of the capacitor C8, and the second end of the capacitor C8 is grounded; the first in-phase input terminal of the operational amplifier chip U2 is connected to the first terminal of the resistor R6, the first terminal of the resistor R7, and the first terminal of the capacitor C10, the second terminal of the resistor R6 is connected to the second output terminal of the first amplifying module 200 (i.e., the second output terminal of the differential isolation amplifier chip U1 shown in fig. 2), and the second terminal of the resistor R7 and the second terminal of the capacitor C10 are connected to the second in-phase input terminal and the second output terminal of the operational amplifier chip U2.
The first inverting input terminal of the operational amplifier chip U2 is connected to the first terminal of the resistor R5, the first terminal of the resistor R4, and the first terminal of the capacitor C7, the second terminal of the resistor R5 is connected to the first output terminal of the first amplifying module 200 (i.e., the first output terminal of the differential isolation amplifier chip U1 shown in fig. 2), the second terminal of the resistor R4 is connected to the second terminal of the capacitor C7, the first terminal of the resistor R3, and the first output terminal of the operational amplifier chip U2, the second terminal of the resistor R3 is connected to the first terminal of the capacitor C6 and the input terminal of the control module 400, and the second terminal of the capacitor C6 is grounded; the second non-inverting input of the op-amp chip U2 is connected to the first terminal of the capacitor C9 and the output of the reference voltage module 500 (i.e., VREF_1V65 of FIG. 3), and the second terminal of the capacitor C9 is grounded.
In this embodiment, the operational amplifier chip U2 is an operational amplifier chip integrating two paths of operational amplifiers, having a low quiescent current of 200uA, a wide bandwidth of 10MHz, and ultra-low noise, the first path of operational amplifier circuit is used for differential proportional amplification of the first isolation signal TN and the second isolation signal TP, and the second path of operational amplifier circuit is used for voltage following of the reference voltage module 400. Specifically, the reference voltage output by the reference voltage module 400 is output to the input end of the first path of operational amplifier circuit after passing through the second path of operational amplifier circuit voltage, so as to increase the reference voltage of the first path of operational amplifier circuit, and the purpose of measuring the forward/reverse current is to measure the forward/reverse current. According to the characteristics of the operational amplifier such as the virtual break and the virtual short, the converted voltage vc=r4/r5 (TP-TN) +1.65v=4.1×1.6×i×10 output by the second amplifying module 300 can be obtained -3 +1.65V＝6.56*I*10 -3 +1.65V。
The output voltage of the second voltage source 3v3_lv is 3.3V.
It should be noted that, through selecting the shunt of different specifications and selecting the resistance of different proportions of first amplification module and second amplification module, can realize the multiscale current sampling of this current sampling circuit.
In the embodiment of the present application, a specific implementation manner of a reference voltage module 500 is provided, and a circuit structure diagram of the reference voltage module 500 is shown in fig. 4, where the reference voltage module 500 includes a voltage reference chip U3, a resistor R8, a resistor R9, a capacitor C11, and a capacitor C12.
The input end of the voltage reference chip U3 is connected to the first end of the capacitor C11 and the third voltage source, the output end of the voltage reference chip U3 is connected to the first end of the capacitor C12 and the first end of the resistor R8, the second end of the resistor R8 is connected to the third input end of the second amplifying module 300 (i.e., the second in-phase input end of the operational amplifier chip U2 shown in fig. 3) and the first end of the resistor R9, and the second end of the resistor R9, the second end of the capacitor C11, the second end of the capacitor C12 and the ground of the voltage reference chip U3 are grounded.
The output voltage of the third voltage source is 5V, and the resistances of the resistor R8 and the resistor R9 are equal.
Specifically, the third voltage source provides the voltage reference chip U3 with a working voltage, the voltage reference chip U3 converts the working voltage into a stable voltage of 3.3V, and then the stable reference voltage of 1.65V is obtained by dividing the voltage through the resistor R8 and the resistor R9 having the same resistance value.
In this embodiment of the present application, the control module 400 at least includes a single-chip microcomputer, and the single-chip microcomputer collects the voltage value of the converted voltage Vc through the AD, and then calculates the current value of the high-voltage sampling current, where the calculation formula is as follows: i=10 3 *250*R5*(Vc-1.65)/(50*8*R4)＝10 3 *(Vc-1.65)/6.56A。
In other embodiments of the present application, the control module 400 includes a single-chip microcomputer and a hall current sensor, wherein the hall current sensor is configured to collect a conversion current generated by a conversion voltage, and the single-chip microcomputer is configured to calculate a high-voltage current signal according to the conversion current.
Compared with the prior art, the embodiment of the invention converts the high-voltage current signal into two paths of low-voltage signals through the current divider, the first amplifying module and the second amplifying module carry out isolation amplification and proportional operation amplification on the two paths of voltage signals, and finally the control module calculates according to the voltage signals to obtain the high-voltage current signal, so that the premise of ensuring the sampling precision, the multi-range premise can be realized, the anti-interference performance and the reliability are improved, and the bidirectional positive/negative current sampling can be realized at the same time.
In other embodiments of the present application, a current sampling apparatus is also provided based on the current sampling circuit described above, the current sampling apparatus including the current sampling circuit described above.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; the technical features of the above embodiments or in the different embodiments may also be combined under the idea of the present application, the steps may be implemented in any order, and there are many other variations of the different aspects of the present application as above, which are not provided in details for the sake of brevity; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims (10)

1. A current sampling circuit, comprising:
a shunt module for collecting and converting the high voltage electrical signal into a first voltage signal and a second voltage signal;
the first amplifying module is used for carrying out isolation amplification on the first voltage signal and the second voltage signal and outputting a first isolation signal and a second isolation signal;
the second amplifying module is used for carrying out differential proportional amplification on the first isolation signal and the second isolation signal and outputting conversion voltage;
a control module for calculating the high voltage current signal from the converted voltage;
the first output end and the second output end of the current divider module are respectively connected with the first input end and the second input end of the first amplifying module, the first output end and the second output end of the first amplifying module are respectively connected with the first input end and the second input end of the second amplifying module, and the first output end and the second output end of the second amplifying module are respectively connected with the first input end and the second input end of the control module.
2. The circuit of claim 1, further comprising:
and the output end of the reference voltage module is connected to the third input end of the second amplifying module.
3. The circuit of claim 1, wherein the first amplification module comprises a differential isolation amplifier chip U1, a resistor R2, a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4, and a capacitor C5, wherein,
the first signal input end of the differential isolation amplifier chip U1 is connected with the first end of the resistor R1, the second end of the resistor R1 is connected with the first output end of the shunt module, the second signal input end of the differential isolation amplifier chip U1 is connected with the first end of the resistor R2, the second end of the resistor R2 is connected with the second output end of the shunt module, the capacitor C3 is connected between the first end of the resistor R1 and the first end of the resistor R2, the first end of the capacitor C4 is connected with the first end of the resistor R2, the first end of the capacitor C5 is connected with the first end of the resistor R1, and the second end of the capacitor C4 and the second end of the capacitor C5 are grounded;
the first electric energy input end of the differential isolation amplifier chip U1 is connected with a first voltage source and the first end of the capacitor C1, the second electric energy input end of the differential isolation amplifier chip U1 is connected with a second voltage source and the first end of the capacitor C2, and the second end of the capacitor C1 and the second end of the capacitor C2 are grounded;
the first output end of the differential isolation amplifier chip U1 is connected with the first input end of the second amplifying module, and the second output end of the differential isolation amplifier chip U1 is connected with the second input end of the second amplifying module.
4. The circuit of claim 2, wherein the second amplification module comprises an operational amplifier chip U2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a resistor R7, a capacitor C6, a capacitor C7, a capacitor C8, a capacitor C9, and a capacitor C10, wherein,
the operational amplifier chip U2 comprises two paths of operational amplifiers, the electric energy input end of the operational amplifier chip U2 is connected with a second voltage source and the first end of the capacitor C8, and the second end of the capacitor C8 is grounded;
the first non-inverting input terminal of the operational amplifier chip U2 is connected to the first terminal of the resistor R6, the first terminal of the resistor R7 and the first terminal of the capacitor C10, the second terminal of the resistor R6 is connected to the second output terminal of the first amplifying module, and the second terminal of the resistor R7 and the second terminal of the capacitor C10 are connected to the second inverting input terminal and the second output terminal of the operational amplifier chip U2;
the first inverting input terminal of the operational amplifier chip U2 is connected to the first terminal of the resistor R5, the first terminal of the resistor R4 and the first terminal of the capacitor C7, the second terminal of the resistor R5 is connected to the first output terminal of the first amplifying module, the second terminal of the resistor R4 is connected to the second terminal of the capacitor C7, the first terminal of the resistor R3 and the first output terminal of the operational amplifier chip U2, the second terminal of the resistor R3 is connected to the first terminal of the capacitor C6 and the input terminal of the control module, and the second terminal of the capacitor C6 is grounded;
the second non-inverting input terminal of the operational amplifier chip U2 is connected to the first terminal of the capacitor C9 and the output terminal of the reference voltage module, and the second terminal of the capacitor C9 is grounded.
5. The circuit of claim 2, wherein the reference voltage module comprises a voltage reference chip U3, a resistor R8, a resistor R9, a capacitor C11, and a capacitor C12, wherein,
the input end of the voltage reference chip U3 is connected with the first end of the capacitor C11 and the third voltage source, the output end of the voltage reference chip U3 is connected with the first end of the capacitor C12 and the first end of the resistor R8, the second end of the resistor R8 is connected with the third input end of the second amplifying module and the first end of the resistor R9, and the second end of the resistor R9, the second end of the capacitor C11, the second end of the capacitor C12 and the grounding end of the voltage reference chip U3 are grounded.
6. The circuit of claim 2, wherein the reference voltage is 1.65V.
7. A circuit according to claim 3, wherein the differential isolation amplifier chip U1 has a fixed gain of 8.
8. A circuit according to claim 3, wherein the output voltage of the first voltage source is 5V, the output voltage of the second voltage source is 3.3V, and the output voltage of the third voltage source is 5V.
9. The circuit of any one of claims 1-8, wherein the control module comprises a single-chip microcomputer and a hall current sensor, the hall current sensor is configured to collect a switching current generated by the switching voltage, and the single-chip microcomputer is configured to calculate the high-voltage current signal according to the switching current.
10. A current sampling apparatus, comprising:
a current sampling circuit as claimed in any one of claims 1 to 9.
CN202311653635.7A 2023-12-04 2023-12-04 Current sampling circuit and device thereof Pending CN117452058A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311653635.7A CN117452058A (en) 2023-12-04 2023-12-04 Current sampling circuit and device thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311653635.7A CN117452058A (en) 2023-12-04 2023-12-04 Current sampling circuit and device thereof

Publications (1)

Publication Number Publication Date
CN117452058A true CN117452058A (en) 2024-01-26

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ID=89589305

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202311653635.7A Pending CN117452058A (en) 2023-12-04 2023-12-04 Current sampling circuit and device thereof

Country Status (1)

Country Link
CN (1) CN117452058A (en)

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