Self-checking device and self-checking method for voltage signal source

Abstract

The invention discloses a self-checking device and method for a voltage signal source, and the method comprises the steps: outputting a control signal to an electronic switch array through a control unit; an electronic switch array is used for controlling the state of each electronic switch based on the control signal, so that each resistor in the non-inductive resistor network can form different bridge loops to be respectively connected to a measurement loop, and the resistance value ratio of the non-inductive resistor network is adjusted; performing voltage division based on the resistance ratio by using a non-inductive resistance network, and outputting a reference voltage Ux; receiving the measured voltage Uc output by the measured voltage signal source by using a difference amplifier, and amplifying the voltage difference between the measured voltage Uc and the reference voltage Ux to output a difference voltage Uo; receiving a reference voltage U by using a voltmeter, and measuring the reference voltage U and a difference voltage Uo; and calculating a reference voltage Ux, calculating a measured voltage Uc based on the reference voltage Ux and the difference voltage Uo by using a processor, and carrying out self-calibration on the measured voltage signal source based on the measured voltage Uc.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power measurement, and more particularly to a self-checking device and a self-checking method for a voltage signal source. Background Art

[0002] In the power system, the measurement accuracy of power test instruments is crucial. Especially in remote calibration services, the long-term stability and accuracy requirements of on-site metering devices are more stringent. Power test instruments usually rely on a variety of sensors, which convert the measured current, voltage and other signals into voltage signals for subsequent measurement processing. Therefore, ensuring the measurement accuracy of the voltage signal source is directly related to the test accuracy of the entire system.

[0003] At present, the self-calibration technology of voltage signal source has been widely used in various types of power test instruments as a technical means to verify the long-term stability, reliability and accuracy of signal source. Most of the existing self-calibration methods use a single reference voltage source to compare with the voltage signal source to be calibrated to verify the accuracy of the signal source. However, this method can usually only verify the output accuracy of the signal source at a single reference point, and the measurement accuracy of other points depends on the output linearity of the signal source itself and the rate stability between different measurement gears and the reference gear. The limitation of this method is that it can only guarantee the accuracy of the signal at a single calibration point, and lacks effective calibration means for the accuracy of other voltage points. For example, patent CN201610902917X proposes a self-calibration method for an electric energy meter, which automatically determines whether the electric energy meter is working properly by measuring the output value of the reference voltage source and comparing it with the preset value. This method realizes the automatic self-calibration of the electric energy meter, but its calibration point is still limited to the reference source value. The accuracy of other measurement points still depends on the stability and linearity of the signal source measurement circuit. Due to the failure to precisely control the calibration of multiple points, this method has certain technical limitations when faced with complex testing requirements.

[0004] In addition, the performance of the self-calibration system not only depends on the stability of the internal reference source, but is also easily affected by external environmental factors such as temperature, humidity, vibration, etc. These environmental conditions may have an adverse effect on the accuracy of the calibration, resulting in the inability to ensure the long-term stability of the signal source. Especially in remote calibration applications, changes in the external environment are inevitable, further increasing the difficulty of the calibration system. At present, the design of self-calibration equipment in power systems has not fully considered the impact of the above external environmental factors on measurement accuracy, resulting in the performance and reliability of existing equipment in actual use being limited.

[0005] Therefore, there is an urgent need for a self-checking device and a self-checking method for a voltage signal source that can effectively cope with the influence of external environmental changes, so as to ensure the long-term stability and accuracy of the signal source. Summary of the invention

[0006] The present invention provides a self-checking device and a self-checking method for a voltage signal source, so as to solve the problem of how to perform self-checking on the voltage signal source efficiently.

[0007] In order to solve the above problem, according to one aspect of the present invention, a self-checking device for a voltage signal source is provided, the device comprising: a control unit, an electronic switch array, a non-inductive resistor network, a difference amplifier and a voltmeter connected in sequence; wherein,

[0008] The control unit is used to output a control signal to the electronic switch array;

[0009] The electronic switch array is used to control the state of each electronic switch based on the control signal, so that each resistor in the non-inductive resistor network can form different bridge loops and be respectively connected to the measurement loop, thereby adjusting the resistance ratio of the non-inductive resistor network;

[0010] The non-inductive resistor network is used to receive a reference voltage U and divide the voltage based on the resistance ratio to output a divided voltage value U x ;

[0011] The differential amplifier is used to receive the measured voltage U output by the measured voltage signal source. c , and the measured voltage U c And the voltage divider value U x The voltage difference is amplified to output the difference voltage U o ;

[0012] The voltmeter is used to receive a reference voltage U and measure the reference voltage U and a difference voltage U o ;

[0013] A processor connected to the output end of the differential amplifier is used to calculate the voltage division value U x , based on the voltage divider value U x And the difference voltage U o Calculate the measured voltage U c , and based on the measured voltage U c Perform self-calibration on the voltage signal source under test.

[0014] Preferably, the electronic switch array, the non-inductive resistor network and the differential amplifier output a differential voltage U based on the bridge differential measurement principle. o The bridge circuit includes: a reference resistor, a measured resistor, a first bridge reference arm resistor and a second bridge reference arm resistor.

[0015] Preferably, the electronic switch is a low on-resistance non-inductive electronic switch; and the difference amplifier is a zero-drift amplifier.

[0016] According to another aspect of the present invention, there is provided a self-checking method for a voltage signal source based on the self-checking device for the voltage signal source as described above, the method comprising:

[0017] Using the control unit to output a control signal to the electronic switch array;

[0018] Using the electronic switch array to control the state of each electronic switch based on the control signal, so that each resistor in the non-inductive resistor network can form different bridge loops and be respectively connected to the measurement loop, thereby adjusting the resistance ratio of the non-inductive resistor network;

[0019] The non-inductive resistor network is used to divide the voltage based on the resistance ratio to output the reference voltage U x ;

[0020] The measured voltage U output by the measured voltage signal source is received by the differential amplifier. c , and the measured voltage U c and reference voltage U x The voltage difference is amplified to output the difference voltage U o ;

[0021] The reference voltage U is received by a voltmeter, and the reference voltage U and the difference voltage U are measured. o ;

[0022] The reference voltage U is calculated by a processor x , based on the reference voltage U x And the difference voltage U o Calculate the measured voltage U c , and based on the measured voltage U c Perform self-calibration on the voltage signal source under test.

[0023] Preferably, the reference voltage U x And the difference voltage U o Calculate the measured voltage U c ,include:

[0024] U c =U x -U o / k,

[0025] Wherein, k is the gain factor of the differential amplifier.

[0026] Preferably, based on the measured voltage U c Self-calibration of the voltage signal source under test, including:

[0027] If the measured voltage U c If the error between the required voltage output by the voltage signal source under test is within a preset range, it is determined that the voltage signal source under test meets the requirement; otherwise, it is determined that the voltage signal source under test does not meet the requirement.

[0028] Preferably, the electronic switch is a low on-resistance non-inductive electronic switch; and the difference amplifier is a zero-drift amplifier.

[0029] Preferably, the method calculates the partial pressure value U in the following manner: x ,include:

[0030] When the resistor R1 is connected to any resistor R x When connected to the bridge circuit, use the formula U x / U=(1+k2+…+k x ) / (1+k2+…+k x +…+k n ) Calculate the voltage divider value U x ;

[0031] Among them, U is the reference voltage; k2, k x and k n They are R2 and R x and R n The resistance ratio of R1, R2, R x ,……,R n Connect in series, one end of R1 is grounded, and the resistor R2 is connected to the resistor R n One end of each resistor is connected to one end of the switch K, and the other end of the switch K is connected to the difference amplifier, 2≤x≤n; n is the number of resistors.

[0032] Preferably, the method further comprises:

[0033] Set either resistor R x Connecting to the bridge circuit, obtaining a first difference voltage Uox based on the current bridge circuit input reference voltage U;

[0034] The two bridge reference arm resistors in the current bridge loop are swapped to obtain a new bridge loop, and a reference voltage U is input to obtain a second difference voltage Uox';

[0035] Using formula k x =R x / R1=2 / [(Uox+Uox') / (kU)+1]–1Calculate R x The resistance ratio of R1 to R2; k is the amplification factor of the differential amplifier.

[0036] The present invention provides a self-checking device and a self-checking method for a voltage signal source, wherein the device comprises: a processor, and a control unit, an electronic switch array, a non-inductive resistor network, a differential amplifier and a voltmeter connected in sequence; the self-checking method comprises: using the control unit to output a control signal to the electronic switch array; using the electronic switch array to control the state of each electronic switch based on the control signal, so that each resistor in the non-inductive resistor network can form different bridge loops and be respectively connected to a measurement loop, thereby adjusting the resistance ratio of the non-inductive resistor network; using the non-inductive resistor network to divide the voltage based on the resistance ratio, and outputting a reference voltage U x ; Use the differential amplifier to receive the measured voltage U output by the measured voltage signal source c , and the measured voltage U c and reference voltage U x The voltage difference is amplified to output the difference voltage U o ; Using a voltmeter to receive a reference voltage U and measure the reference voltage U and the difference voltage U o ; Using the processor to calculate the reference voltage U x , based on the reference voltage U x And the difference voltage U o Calculate the measured voltage U c , and based on the measured voltage U c The voltage signal source under test is self-calibrated; the present invention can realize multi-point calibration under the condition of a single reference source, and can solve the dependence on the linearity and rate stability of the signal source in the traditional method, thereby significantly improving the accuracy of the voltage signal source in multi-point measurement, and improving the reliability and practicality of the equipment in the remote calibration service. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0038] Figure 1 It is a structural schematic diagram of a self-checking device 100 for a voltage signal source according to an embodiment of the present invention;

[0039] Figure 2 A connection diagram of a self-checking device for a voltage signal source according to an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of a resistance ratio measurement circuit based on a bridge difference measurement principle according to an embodiment of the present invention;

[0041] Figure 4 A schematic diagram of a multi-resistance ratio measurement circuit based on an electronic switch array according to an embodiment of the present invention;

[0042] Figure 5A schematic diagram of a circuit for verifying a voltage signal based on a precision non-inductive resistor ratio array according to an embodiment of the present invention;

[0043] Figure 6 FIG. 6 is a flow chart of a self-checking method 600 for a voltage signal source according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0045] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0046] Figure 1 FIG. 1 is a schematic diagram of the structure of a self-checking device 100 for a voltage signal source according to an embodiment of the present invention. Figure 1 As shown, the self-checking device of the voltage signal source provided by the embodiment of the present invention can realize multi-point calibration under the condition of a single reference source, and can solve the dependence on the linearity and rate stability of the signal source in the traditional method, thereby significantly improving the accuracy of the voltage signal source in multi-point measurement, and improving the reliability and practicality of the equipment in remote calibration services. The self-checking device 100 of the voltage signal source provided by the embodiment of the present invention includes: a control unit 101, an electronic switch array 102, a non-inductive resistor network 103, a differential amplifier 104 and a voltmeter 105 connected in sequence; and a processor 106.

[0047] Preferably, the control unit 101 is used to output a control signal to the electronic switch array.

[0048] Preferably, the electronic switch array 102 is used to control the state of each electronic switch based on the control signal, so that each resistor in the non-inductive resistor network can form different bridge loops and be respectively connected to the measurement loop, thereby adjusting the resistance ratio of the non-inductive resistor network.

[0049] Preferably, the non-inductive resistor network 103 is used to receive a reference voltage U, and divide the voltage based on the resistance ratio to output a divided voltage value U x .

[0050] Preferably, the differential amplifier 104 is used to receive the measured voltage U output by the measured voltage signal source. c , and the measured voltage U c And the voltage divider value U x The voltage difference is amplified to output the difference voltage U o .

[0051] Preferably, the voltmeter 105 is used to receive a reference voltage U and measure the reference voltage U and a difference voltage U o .

[0052] Preferably, the processor 106 is connected to the output end of the differential amplifier and is used to calculate the voltage division value U x , based on the voltage divider value U x And the difference voltage U o Calculate the measured voltage U c , and based on the measured voltage U c Perform self-calibration on the voltage signal source under test.

[0053] Preferably, the electronic switch array, the non-inductive resistor network and the differential amplifier output a differential voltage U based on the bridge differential measurement principle. o The bridge circuit includes: a reference resistor, a measured resistor, a first bridge reference arm resistor and a second bridge reference arm resistor.

[0054] Preferably, the electronic switch is a low on-resistance non-inductive electronic switch; and the difference amplifier is a zero-drift amplifier.

[0055] Preferably, the method calculates the partial pressure value U in the following manner: x ,include:

[0056] When the resistor R1 is connected to any resistor R x When connected to the bridge circuit, use the formula U x / U=(1+k2+…+k x ) / (1+k2+…+k x +…+k n ) Calculate the voltage divider value U x ;

[0057] Among them, U is the reference voltage; k2, k x and k n They are R2 and R x and R n The resistance ratio of R1, R2, R x ,……,R n Connect in series, one end of R1 is grounded, and the resistor R2 is connected to the resistor R nOne end of each resistor is connected to one end of the switch K, and the other end of the switch K is connected to the difference amplifier, 2≤x≤n; n is the number of resistors.

[0058] Preferably, the method further comprises:

[0059] Set either resistor R x Connecting to the bridge circuit, obtaining a first difference voltage Uox based on the current bridge circuit input reference voltage U;

[0060] The two bridge reference arm resistors in the current bridge loop are swapped to obtain a new bridge loop, and a reference voltage U is input to obtain a second difference voltage Uox';

[0061] Using formula k x =R x / R1=2 / [(Uox+Uox') / (kU)+1]–1Calculate R x The resistance ratio of R1 to R2; k is the amplification factor of the differential amplifier.

[0062] Combination Figure 2 As shown, in the present invention, the voltage signal originates from the calibration device, which is composed of a precision non-inductive resistor network, an electronic switch array, a differential amplifier, a voltmeter, a control unit, and a processor (not shown in the figure). The control unit outputs a control signal to control the states of the switches in the electronic switch array, switches the connection of each resistor in the precision non-inductive resistor network, and combines each resistor into a bridge circuit. The precision non-inductive resistor network receives a reference voltage U and outputs a voltage divider value U x ; The differential amplifier amplifies the voltage divider value U output by the bridge circuit x And the measured voltage U c The weak voltage difference, output differential voltage U o ; The voltmeter measures the differential voltage U o and the reference voltage U of the input bridge circuit; the processor calculates the voltage division value U x , based on the voltage divider value U x And the difference voltage U o Calculate the measured voltage U c , and based on the measured voltage U c Perform self-calibration on the voltage signal source under test.

[0063] In the present invention, the electronic switch array, the non-inductive resistor network and the differential amplifier output the differential voltage U based on the bridge differential measurement principle. o The bridge circuit includes: a reference resistor, a measured resistor, a first bridge reference arm resistor, and a second bridge reference arm resistor. The resistance ratio measurement circuit based on the bridge difference measurement principle of the present invention is as follows: Figure 3 As shown, R1 is the reference resistor, R2 is the resistor to be measured, R1b , R 2b is the bridge reference arm resistance, K 1b , K 2b is the symbol of the electronic switch, k is the gain factor of the differential amplifier, U is the input reference voltage, U1 and U2 are the median voltages of the two arms of the bridge, and U o is the output voltage after the difference is amplified. 1b , R 2b They are all high-precision, low temperature coefficient, non-inductive resistors with similar resistance values, K 1b , K 2b It is a low on-resistance non-inductive electronic switch, and k is the gain factor of the zero-drift precision instrument amplifier.

[0064] Initial state, electronic switch K 1b , K 2b Connect the 1st and 2nd terminals of the

[0065] U1 / U=R1 / (R1+R2) (1)

[0066] U2 / U=R 1b / (R 1b +R 2b ) (2)

[0067] U o / U=k[R1 / (R1+R2)-R 1b / (R 1b +R 2b )] (3)

[0068] Then, the electronic switch K 1b , K 2b Connect the 1st and 3rd terminals of the bridge, that is, change the position of the bridge reference arm resistor, and input the reference voltage U, then

[0069] U1 / U=R1 / (R1+R2) (4)

[0070] U2 / U=R 2b / (R 1b +R 2b ) (5)

[0071] U o ' / U=k[R1 / (R1+R2)–R 2b / (R 1b +R 2b )] (6)

[0072] From formula (3) and formula (6), we can get

[0073] (U o +U o') / U=k[(R1-R2) / (R1+R2)] (7)

[0074] R2 / R1=2 / [(U o +U o ') / (k U)+1]-1 (8)

[0075] Because the resistance of R2 is close to that of R1, U o , U o ' is much smaller than k U, that is, U o , U o The measurement error of ' and the deviation of k have little effect on the measurement result of the resistance ratio of R2 to R1, and the bridge reference arm resistance R 1b , R 2b The deviation of has little effect on the measurement result. For example, when k is 100, U o , U o When the absolute value is close to U and the measurement error of the voltmeter is 1%, the influence on the measurement result of the resistance ratio of R2 and R1 is about 0.01%, that is, the high-accuracy measurement of the resistance ratio can be achieved by an ordinary voltmeter.

[0076] In the present invention, the resistors in the precision non-inductive resistor network are connected to the measurement circuit in sequence through the electronic switch array, and the resistance ratio of each resistor to the reference resistor is accurately measured. Figure 4 As shown, R x ,……,R n Replace R2 in the measurement loop in turn to obtain R x ,……,R n Ratio to the resistance of R1.

[0077] In the present invention, the resistors in the precision non-inductive resistor network are connected in series to the measurement loop through an electronic switch array to achieve accurate self-calibration of the voltage signal source. Figure 5 As shown, R1, R2, R x ,……,R n Connect in series, the 1 end of switch K is connected to the 2, x, ..., n ends in sequence, and multiple precise voltage division values ​​U of the reference voltage U are obtained. x .

[0078] Among them, set R2, R x ,……,R n The resistance ratios of R2 and R1 are k2 and k x ,……,k n , then the 1st and 2nd terminals of switch K are connected, and when resistor R1 is connected to the bridge circuit, there exists:

[0079] U x / U=1 / (1+k2+…+k x +…+kn ) (9)

[0080] When the 1 terminal and the x terminal of the switch K are connected, the resistor R1 is connected to any resistor R x When connected to the bridge circuit, there are:

[0081] U x / U=(1+k2+…+k x ) / (1+k2+…+k x +…+k n ) (10)

[0082] When the 1 and n terminals of switch K are connected, the resistor R1 to the resistor R n When connected to the bridge circuit, there are:

[0083] U x / U=(1+k2+…+k x +…+k n ) / (1+k2+k x +…+k n ) (11)

[0084] Because U c is the output value of the voltage signal source under test, U o is the difference amplifier output value, then we can get:

[0085] U c =U x -U o / k (12)

[0086] From the above formula, we can see that U o The error of the measurement result is c The impact of the measurement result is reduced by k times. x It is an accurate voltage division of the reference voltage U, that is, accurate self-calibration of multiple voltage signal sources can be achieved through a single reference voltage source.

[0087] Specifically, in the present invention, the self-checking method of the voltage signal source is as follows: Figure 6 As shown in the figure, the self-checking process includes:

[0088] Step 601: Use a control unit to output a control signal to an electronic switch array.

[0089] Step 602: Using the electronic switch array to control the state of each electronic switch based on the control signal, so that each resistor in the non-inductive resistor network can form different bridge loops and be respectively connected to the measurement loop, thereby adjusting the resistance ratio of the non-inductive resistor network.

[0090] Step 603: Use a non-inductive resistor network to divide the voltage based on the resistance ratio to output a reference voltage U x.

[0091] Step 604: using a differential amplifier to receive the measured voltage U output by the measured voltage signal source c , and the measured voltage U c and reference voltage U x The voltage difference is amplified to output the difference voltage U o .

[0092] Step 605: Receive a reference voltage U using a voltmeter and measure the reference voltage U and the difference voltage U o .

[0093] Step 606: Calculate the reference voltage U using a processor x , based on the reference voltage U x And the difference voltage U o Calculate the measured voltage U c , and based on the measured voltage U c Perform self-calibration on the voltage signal source under test.

[0094] Preferably, the reference voltage U x And the difference voltage U o Calculate the measured voltage U c ,include:

[0095] U c =U x -U o / k,

[0096] Wherein, k is the gain factor of the differential amplifier.

[0097] Preferably, based on the measured voltage U c Self-calibration of the voltage signal source under test, including:

[0098] If the measured voltage U c If the error between the required voltage output by the voltage signal source under test is within a preset range, it is determined that the voltage signal source under test meets the requirement; otherwise, it is determined that the voltage signal source under test does not meet the requirement.

[0099] Preferably, the method calculates the partial pressure value U in the following manner: x ,include:

[0100] When the resistor R1 is connected to any resistor R x When connected to the bridge circuit (when the 1 terminal of switch K is connected to the x terminal), use the formula U x / U=(1+k2+…+k x ) / (1+k2+…+k x +…+k n ) Calculate the voltage divider value Ux ;

[0101] Among them, U is the reference voltage; k2, k x and k n They are R2 and R x and R n The resistance ratio of R1, R2, R x ,……,R n Connect in series, one end of R1 is grounded, and the resistor R2 is connected to the resistor R n One end of each resistor is connected to one end of the switch K, and the other end of the switch K is connected to the difference amplifier, 2≤x≤n; n is the number of resistors.

[0102] Preferably, the method further comprises:

[0103] Set either resistor R x Connecting to the bridge circuit, obtaining a first difference voltage Uox based on the current bridge circuit input reference voltage U;

[0104] The two bridge reference arm resistors in the current bridge loop are swapped to obtain a new bridge loop, and a reference voltage U is input to obtain a second difference voltage Uox';

[0105] Using formula k x =R x / R1=2 / [(Uox+Uox') / (kU)+1]–1Calculate R x The resistance ratio of R1 to R2; k is the amplification factor of the differential amplifier.

[0106] The present invention significantly improves the accuracy and stability of voltage measurement by adopting a voltage divider network composed of precision non-inductive resistors and combining the measurement means of non-inductive low on-resistance relays and digital bridges. The voltage divider network design ensures the accuracy and linearity of the measurement signal during the measurement of different voltage points. Through the measurement of normalized ratios and the acquisition of self-calibration parameters, the present invention realizes accurate self-calibration of multi-point measurement parameters of the voltage signal source, solving the problems of single calibration point and susceptibility to external interference and equipment aging during the calibration process in traditional methods. By directly measuring the multi-point signal source, the self-calibration accuracy of the voltage signal source is further improved, ensuring long-term stability and reliability in practical applications.

[0107] The mechanism of switching the resistor network voltage divider ratio adopted by the present invention enables the present invention to flexibly adapt to various measurement requirements, reduces the errors that may occur during the calibration process, and further improves the robustness of the system. Compared with the prior art, the present invention significantly improves the self-calibration efficiency of the voltage signal source by simplifying the calibration process and ensuring multi-point accurate measurement, and overcomes the limitations of the traditional single reference source comparison method. In short, while maintaining the measurement accuracy, the present invention enhances the long-term stability and environmental adaptability of the system and has a wide range of application prospects.

[0108] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0109] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise therein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of said means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

[0110] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0111] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0112] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0113] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A self-checking device for a voltage signal source, characterized in that: The device comprises: a control unit, an electronic switch array, a non-inductive resistor network, a differential amplifier and a voltmeter connected in sequence; wherein, The control unit is used to output a control signal to the electronic switch array; The electronic switch array is used to control the state of each electronic switch based on the control signal, so that each resistor in the non-inductive resistor network can form different bridge loops and be respectively connected to the measurement loop, thereby adjusting the resistance ratio of the non-inductive resistor network; The non-inductive resistor network is used to receive a reference voltage U and divide the voltage based on the resistance ratio to output a divided voltage value U x ; The differential amplifier is used to receive the measured voltage U output by the measured voltage signal source. c , and the measured voltage U c And the voltage divider value U x The voltage difference is amplified to output the difference voltage U o ; The voltmeter is used to receive a reference voltage U and measure the reference voltage U and a difference voltage U o ; A processor connected to the output end of the differential amplifier is used to calculate the voltage division value U x , based on the voltage divider value U x And the difference voltage U o Calculate the measured voltage U c , and based on the measured voltage U c Perform self-calibration on the voltage signal source under test.

2. The device according to claim 1, characterized in that The electronic switch array, the non-inductive resistor network and the differential amplifier output a differential voltage U based on the bridge differential measurement principle. o .

3. The device according to claim 1, characterized in that The electronic switch is a low on-resistance non-inductive electronic switch; and the difference amplifier is a zero-drift amplifier.

4. A self-checking method for a voltage signal source based on the self-checking device for a voltage signal source according to any one of claims 1 to 3, characterized in that: The method comprises: Using the control unit to output a control signal to the electronic switch array; Using the electronic switch array to control the state of each electronic switch based on the control signal, so that each resistor in the non-inductive resistor network can form different bridge loops and be respectively connected to the measurement loop, thereby adjusting the resistance ratio of the non-inductive resistor network; The non-inductive resistor network is used to divide the voltage based on the resistance ratio, and the output voltage division value U x ; The measured voltage U output by the measured voltage signal source is received by the differential amplifier. c , and the measured voltage U c And the voltage divider value U x The voltage difference is amplified to output the difference voltage U o ; The reference voltage U is received by a voltmeter, and the reference voltage U and the difference voltage U are measured. o ; The voltage division value U is calculated by a processor x , based on the voltage divider value U x And the difference voltage U o Calculate the measured voltage U c , and based on the measured voltage U c Perform self-calibration on the voltage signal source under test.

5. The method according to claim 4, characterized in that The partial pressure value U x And the difference voltage U o Calculate the measured voltage U c , include: IN c =U x -IN o / k, Wherein, k is the gain factor of the differential amplifier.

6. The method according to claim 5, characterized in that Based on the measured voltage U c Self-calibration of the voltage signal source under test, including: If the measured voltage U c If the error between the required voltage output by the voltage signal source under test is within a preset range, it is determined that the voltage signal source under test meets the requirement; otherwise, it is determined that the voltage signal source under test does not meet the requirement.

7. The device according to claim 4, characterized in that The electronic switch is a low on-resistance non-inductive electronic switch; and the difference amplifier is a zero-drift amplifier.

8. The method according to claim 4, characterized in that The method calculates the partial pressure value U in the following way x ,include: When the resistor R1 is connected to any resistor R x When connected to the bridge circuit, use the formula U x / U=(1+k2+…+k x ) / (1+k2+…+k x +…+k n ) Calculate the voltage divider value U x ; Among them, U is the reference voltage; k2, k x and k n They are R2 and R x and R n The resistance ratio of R1, R2, R x ,……,R n Connect in series, one end of R1 is grounded, and the resistor R2 is connected to the resistor R n One end of each resistor is connected to one end of the switch K, and the other end of the switch K is connected to the difference amplifier, 2≤x≤n; n is the number of resistors.

9. The method according to claim 8, characterized in that The method further comprises: Set either resistor R x Connecting to the bridge circuit, obtaining a first difference voltage Uox based on the current bridge circuit input reference voltage U; The two bridge reference arm resistors in the current bridge loop are swapped to obtain a new bridge loop, and the reference voltage U is input to obtain the second difference voltage Uox. ’ ; Using formula k x =R x / R1=2 / [(Uox+Uox ’ ) / (kU)+1]–1Calculate R x The resistance ratio of R1 to R2; k is the amplification factor of the differential amplifier.

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