Direct-current high-voltage high-resistance measuring circuit and measuring method

Abstract

The invention relates to a direct-current high-voltage high-resistance measuring circuit and a measuring method, which are characterized in that an existing voltage division method circuit adopting an operational amplifier is innovated and improved, a linked switch is introduced into the high-resistance measuring circuit, and two groups of voltage and resistance measuring loops are respectively controlled by the linked switch; the resistance value of the to-be-measured resistor can be directly calculated according to the resistance value of the standard resistor and the voltages on the two voltage resistance measurement loops, so that the influence of resistance value drift of the divider resistor and the sampling resistor and voltage drift of the power supply on the measurement precision of the high resistance is avoided. And particularly, when high resistance with the level of 100 M omega or G omega or above is measured, the measurement precision is very high.

Description

Technical Field

[0001] The invention belongs to the technical field of direct current high voltage and high value resistance measurement, and relates to a direct current high voltage and high resistance measurement circuit and a measurement method. Background Art

[0002] DC high-voltage high-value resistors (hereinafter referred to as high-resistance resistors) are mainly used as standard devices for calibrating insulation resistance meters and high-resistance meters. The accuracy of their calibration is very important to the safety of the power system, so the industry needs to regularly conduct traceability calibration of high-resistance resistors. The existing JJG 1072-2011 "DC high-voltage high-value resistor" calibration regulations propose three methods for the principle of high-resistance traceability calibration, namely, the voltage division method using operational amplifiers, the voltage division method, and the bridge method. When measuring or verifying high resistance using the voltage divider method of an operational amplifier as proposed in the verification regulations of JJG 1072-2011 "DC High Voltage High Value Resistors", the actual resistance values ​​of the voltage divider resistors and sampling resistors used will drift with environmental factors and time, which will significantly affect the measurement accuracy of high resistance. For high resistances above 100MΩ or GΩ, the resistance drift of the voltage divider resistors and sampling resistors is particularly significant, which greatly limits the measurement accuracy of high resistances. At the same time, the voltage source may also drift, which will also affect the measurement accuracy of high resistances. Therefore, how to prevent the above drift from affecting the measurement accuracy of high resistances has become a technical problem that has been waiting to be solved. Summary of the invention

[0003] In view of the above problems, the present invention proposes a DC high-voltage high-resistance measurement circuit and two DC high-voltage high-resistance measurement methods, which can effectively avoid the drift affecting the measurement accuracy of high resistance, thereby improving the measurement accuracy.

[0004] In order to achieve the above objectives, the embodiments of the present invention adopt the following technical solutions: On the one hand, a DC high-voltage high-resistance measurement circuit is provided, comprising a DC voltage source, a standard resistor, a resistor to be measured, a linkage switch, a first operational amplifier, a second operational amplifier, a first voltage-dividing sampling resistor, and a second voltage-dividing sampling resistor; The negative end of the DC voltage source is grounded, the positive end of the DC voltage source is respectively connected to one end of a standard resistor and one end of a resistor to be measured, the other end of the standard resistor is connected to the inverting input end of the first operational amplifier or the second operational amplifier through a linkage switch, the other end of the resistor to be measured is connected to the inverting input end of the first operational amplifier or the second operational amplifier through a linkage switch, the non-inverting input ends of the first operational amplifier and the second operational amplifier are both grounded, the first voltage-dividing sampling resistor is connected across the output end and the inverting input end of the first operational amplifier, and the second voltage-dividing sampling resistor is connected across the output end and the inverting input end of the second operational amplifier; When the linkage switch is closed in the first switch position, the standard resistor and the first voltage-dividing sampling resistor form a first voltage measurement circuit, and the resistor to be measured and the second voltage-dividing sampling resistor form a first resistance measurement circuit. When the linkage switch is closed in the second switch position, the resistor to be measured and the first voltage-dividing sampling resistor form a second resistance measurement circuit, and the standard resistor and the second voltage-dividing sampling resistor form a second voltage measurement circuit; the standard resistor, the voltage on the first voltage measurement circuit, the voltage on the first resistance measurement circuit, the voltage on the second resistance measurement circuit, and the voltage on the second voltage measurement circuit are used to determine the resistance value of the resistor to be measured.

[0005] On the other hand, a DC high-voltage high-resistance measurement method is also provided. The method is based on a DC high-voltage high-resistance measurement circuit. The DC high-voltage high-resistance measurement circuit is configured to be connected to a voltage measurement device. The DC high-voltage high-resistance measurement circuit includes a DC voltage source, a standard resistor, a resistor to be measured, a linkage switch, a first operational amplifier, a second operational amplifier, a first voltage-dividing sampling resistor, and a second voltage-dividing sampling resistor; The negative end of the DC voltage source is grounded, the positive end of the DC voltage source is respectively connected to one end of a standard resistor and one end of a resistor to be measured, the other end of the standard resistor is connected to the inverting input end of the first operational amplifier or the second operational amplifier through a linkage switch, the other end of the resistor to be measured is connected to the inverting input end of the first operational amplifier or the second operational amplifier through a linkage switch, the non-inverting input ends of the first operational amplifier and the second operational amplifier are both grounded, the first voltage-dividing sampling resistor is connected across the output end and the inverting input end of the first operational amplifier, and the second voltage-dividing sampling resistor is connected across the output end and the inverting input end of the second operational amplifier; When the linkage switch is closed in the first switch position, the standard resistor and the first voltage-dividing sampling resistor form a first voltage measurement loop, and the resistor to be measured and the second voltage-dividing sampling resistor form a first resistance measurement loop. When the linkage switch is closed in the second switch position, the resistor to be measured and the first voltage-dividing sampling resistor form a second resistance measurement loop, and the standard resistor and the second voltage-dividing sampling resistor form a second voltage measurement loop. The DC high voltage high resistance measurement method comprises the following steps: Control the linkage switch to close at the first switch position to construct a first voltage measurement loop and a first resistance measurement loop; Measuring the voltage on the first voltage measurement loop and the voltage on the first resistance measurement loop by a voltage measurement device; Control the linkage switch to close at the second switch position to construct a second resistance measurement loop and a second voltage measurement loop; Measuring the voltage on the second resistance measurement loop and the voltage on the second voltage measurement loop by a voltage measurement device; The resistance value of the resistor to be measured is calculated according to the resistance value of the standard resistor, the voltage on the first voltage measurement loop, the voltage on the first resistance measurement loop, the voltage on the second resistance measurement loop and the voltage on the second voltage measurement loop.

[0006] In another aspect, another DC high-voltage high-resistance measurement method is provided, the method is based on a DC high-voltage high-resistance measurement circuit, the DC high-voltage high-resistance measurement circuit is configured to be connected to a voltage ratio measurement device, the DC high-voltage high-resistance measurement circuit includes a DC voltage source, a standard resistor, a resistor to be measured, a linkage switch, a first operational amplifier, a second operational amplifier, a first voltage-dividing sampling resistor, and a second voltage-dividing sampling resistor; The negative end of the DC voltage source is grounded, the positive end of the DC voltage source is respectively connected to one end of a standard resistor and one end of a resistor to be measured, the other end of the standard resistor is connected to the inverting input end of the first operational amplifier or the second operational amplifier through a linkage switch, the other end of the resistor to be measured is connected to the inverting input end of the first operational amplifier or the second operational amplifier through a linkage switch, the non-inverting input ends of the first operational amplifier and the second operational amplifier are both grounded, the first voltage-dividing sampling resistor is connected across the output end and the inverting input end of the first operational amplifier, and the second voltage-dividing sampling resistor is connected across the output end and the inverting input end of the second operational amplifier; When the linkage switch is closed in the first switch position, the standard resistor and the first voltage-dividing sampling resistor form a first voltage measurement loop, and the resistor to be measured and the second voltage-dividing sampling resistor form a first resistance measurement loop. When the linkage switch is closed in the second switch position, the resistor to be measured and the first voltage-dividing sampling resistor form a second resistance measurement loop, and the standard resistor and the second voltage-dividing sampling resistor form a second voltage measurement loop. The DC high voltage high resistance measurement method comprises the following steps: Control the linkage switch to close at the first switch position to construct a first voltage measurement loop and a first resistance measurement loop; Measuring the ratio of the voltage on the first voltage measurement loop and the voltage on the first resistance measurement loop by a voltage ratio measurement device; Control the linkage switch to close at the second switch position to construct a second resistance measurement loop and a second voltage measurement loop; Measuring the ratio of the voltage on the second resistance measurement loop to the voltage on the second voltage measurement loop by a voltage ratio measurement device; The resistance value of the resistor to be measured is calculated according to the resistance value of the standard resistor, the ratio of the voltage on the first voltage measurement loop and the first resistance measurement loop, and the ratio of the voltage on the second resistance measurement loop and the second voltage measurement loop.

[0007] The above technical solution has the following advantages and beneficial effects: The above-mentioned DC high-voltage high-resistance measurement circuit and measurement method, through innovative improvement of the existing voltage divider method circuit using an operational amplifier, introduce a linkage switch into the high-resistance measurement circuit and introduce a standard resistor, and the linkage switch is used to control two groups of voltage resistance measurement loops respectively, so that the resistance value of the resistor to be measured can be directly calculated from the resistance value of the standard resistor and the voltage on the two groups of voltage / resistance measurement loops. In this measurement process, there is no need to use the resistance value of the voltage divider resistor and the sampling resistor, and it does not rely on the power supply, thereby avoiding the influence of the resistance drift of the voltage divider resistor and the sampling resistor and the drift of the power supply on the measurement accuracy of the high resistance, and can be used for accurate measurement of high resistance with a resistance range of more than 100 Ω, especially when measuring high resistance of 100MΩ or GΩ or above, it has high measurement accuracy, and the measurement uncertainty can be controlled to within 50ppm (Parts Per Million, referred to as ppm). BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0009] Figure 1 The schematic diagram of the principle circuit of the voltage division method using an operational amplifier in one embodiment; Figure 2 A schematic diagram of the structure of a DC high-voltage high-resistance measurement circuit in one embodiment; Figure 3 A schematic diagram of the structure of a DC high-voltage high-resistance measurement circuit in another embodiment; Figure 4 1 is a flow chart of a DC high voltage high resistance measurement method in one embodiment; Figure 5 FIG. 4 is a flow chart of a DC high voltage high resistance measurement method in another embodiment. DETAILED DESCRIPTION

[0010] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0011] It should be noted that the reference to "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The presentation of this phrase at various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It will be appreciated by those skilled in the art that the embodiments described herein may be combined with other embodiments. The term "and / or" used in the specification of the present invention and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0012] The following will describe the implementation of the present invention in detail with reference to the accompanying drawings in the embodiment diagram of the present invention.

[0013] The principle of "using the voltage division method of operational amplifier" proposed in the existing JJG 1072-2011 "DC high voltage and high value resistor" verification regulations is as follows Figure 1 As shown, the circuit consists of resistors R O and resistor R B The voltage measurement circuit is composed of the measured resistance R x and R A The resistance measurement circuit is composed of R x It is calculated by the following formula:

[0014] In the above formula, R O and R B It is the voltage measuring circuit voltage dividing resistor. R A Sampling resistance for resistance measurement circuit, R x is the resistance to be measured, V b Power supply voltage V The output voltage after voltage division is V a The sampling resistor R A The voltage on.

[0015] When measuring or calibrating high resistance using the voltage divider method using an operational amplifier as proposed in the calibration procedure JJG 1072-2011 "DC High-Voltage High-Value Resistors", the actual resistance values ​​of the voltage divider resistors and sampling resistors used will drift with environmental and time factors, which will significantly affect the measurement accuracy of the high resistance. For high resistances of 100MΩ or GΩ or above, the resistance drift of the voltage divider resistors and sampling resistors is particularly significant, which greatly limits the measurement accuracy of the high resistance. At the same time, the power supply may also drift, which will also affect the measurement accuracy of the high resistance.

[0016] In one embodiment, Figure 2 As shown, a DC high voltage high resistance measurement circuit 100 is provided. The DC high voltage high resistance measurement circuit 100 includes a DC voltage source DC , Standard resistance R S 、Resistance to be measured R x , linkage switch S, first operational amplifier OP1, second operational amplifier OP2, first voltage-dividing sampling resistor R a And the second voltage divider sampling resistor R b . DC voltage source DC The negative terminal of the DC voltage source is grounded. DC Connect the positive end of the standard resistor R S One end and the resistance to be measured R x Standard resistor R S The other end is connected to the inverting input terminal of the first operational amplifier OP1 or the second operational amplifier OP2 through a linkage switch S. R x The other end is connected to the inverting input terminal of the first operational amplifier OP1 or the second operational amplifier OP2 through a linkage switch S. The non-inverting input terminals of the first operational amplifier OP1 and the second operational amplifier OP2 are both grounded. R a The second voltage-dividing sampling resistor is connected between the output terminal and the inverting input terminal of the first operational amplifier OP1. R b When the linkage switch S is closed in the first switch position, the standard resistor R S The first voltage divider sampling resistor R a The first voltage measurement circuit is formed, and the resistance to be measured R x The second voltage divider sampling resistor Rb The first resistance measurement circuit is formed. When the linkage switch S is closed in the second switch position, the resistance to be measured R x The first voltage divider sampling resistor R a The second resistance measurement loop is formed, and the standard resistance R S The second voltage divider sampling resistor R b Form the second voltage measurement circuit; standard resistance R S The voltage on the first voltage measurement circuit, the voltage on the first resistance measurement circuit, the voltage on the second resistance measurement circuit, and the voltage on the second voltage measurement circuit are used to determine the resistance to be measured. R x resistance value.

[0017] It can be understood that the linkage switch S can be but is not limited to a double button switch, a double double-contact micro switch, a double-contact combination switch or other structural forms of linkage switches S. The specific type can be selected according to actual use / packaging needs, as long as it can be used to achieve the above-mentioned required circuit construction (switching) function.

[0018] Through the switching function of the circuit connection relationship provided by the linkage switch S, when the linkage switch S is closed in the first switch position, the standard resistor R S and the first voltage divider sampling resistor R a The first voltage measurement circuit is composed of a standard resistor R S And the second voltage divider sampling resistor R b Correspondingly, when the linkage switch S is closed in the second switch position, the resistance to be measured is respectively established. R x And the second voltage divider sampling resistor R b The first resistance measurement circuit is formed, or the resistance to be measured R x and the first voltage divider sampling resistor R a A second resistance measurement loop is formed.

[0019] In one embodiment, Figure 3 As shown, the linkage switch includes a linkage switch S 1 and switch S 2. Switch S The movable contact of 1 is connected to the inverting input terminal of the first operational amplifier OP1, and the switchS 1The first fixed contact is connected to the other end of the standard resistor, and the switch S The second fixed contact of 1 is connected to the other end of the resistor to be measured. S The movable contact of 2 is connected to the inverting input terminal of the second operational amplifier, and the switch S 2 is connected to the other end of the resistor to be measured, and the switch S The second fixed contact of 2 is connected to the other end of the standard resistor.

[0020] Understandably, the linkage switch S 1 and switch S 2 The basic structure of a double-pole double-throw switch can be adopted, or other structures with similar functions can be adopted. The specific structure can be selected according to the actual needs of use, as long as it can be used to provide the required circuit switching function.

[0021] Through the switch S1 at the contact a 1 and contact a 2, respectively, by establishing the standard resistor R S and the first voltage divider sampling resistor R a The first voltage measurement circuit is composed of a standard resistor R S And the second voltage divider sampling resistor R b The second voltage measurement circuit is formed by the switch S 1 Linked switch S 2 at the contact point b 1 and contact b 2, respectively, by the resistance to be measured R x And the second voltage divider sampling resistor R b The first resistance measurement circuit is formed, or the resistance to be measured R x and the first voltage divider sampling resistor R a The second resistance measurement loop is formed. The switch structure is simple, reliable and has lower cost.

[0022] The voltage on the first voltage measurement circuit can be measured using an existing voltage measurement device (which can be recorded as U a1 ) and the voltage on the first resistor measurement loop (which can be written as U b1 ), and use the voltage measuring device to measure the voltage on the second resistance measurement circuit respectively (which can be recorded as U a2) and the voltage on the second voltage measurement circuit (which can be recorded as U b2 ). Through the voltage U a1 ,Voltage U b1 ,Voltage U a2 ,Voltage U b2 And standard resistors R S The resistance value of the resistor to be measured can be directly calculated R x The voltage measuring device is, for example, but not limited to, a voltage detector, a voltage and current tester, or a withstand voltage tester in the art, and the specific type can be selected according to actual use needs.

[0023] Specifically, the resistance to be measured R x The calculation process is as follows: (1) Switch S 1 and contact a 1 connected and switch S 2 and contact b 1 is connected (i.e. one of the first switch positions), the standard resistance R S The first voltage divider sampling resistor R a The first voltage measurement circuit is formed, and the resistance to be measured R x The second voltage divider sampling resistor R b The first resistance measurement circuit is formed. Assume that the DC voltage source is DC The output voltage is U 1, then: Voltage on the first voltage measurement circuit ; The first resistor measures the voltage on the circuit ; The ratio of the voltage on the first voltage measurement circuit to the voltage on the first resistance measurement circuit: Formula (1) (2) Switch S 1 and contact a 2 connected and switch S 2 and contact b 2 is connected (i.e. one of the corresponding second switch positions), the standard resistance R S The second voltage divider sampling resistor R bThe second voltage measurement circuit is formed, and the resistance to be measured R x The first voltage divider sampling resistor R a The second resistance measurement circuit is formed. Assume that the DC voltage source DC The output voltage is U 2, then: The second resistor measures the voltage across the loop ; Voltage on the second voltage measurement circuit ; The ratio of the voltage on the second resistance measurement circuit to the voltage on the second voltage measurement circuit: Formula (2) (3) According to formula (1) and formula (2), we can get: Formula (3) Take the square root of formula (3) and combine it with the standard resistance R S The resistance value of the resistor to be measured can be obtained R x The resistance value is as follows: Formula (4) or, Formula (5) That is, the voltage on the first voltage measurement circuit and the first resistance measurement circuit are measured by using the voltage measurement device. U a1 and U b1 After switching the switch, the voltage measuring device is used to measure the voltage on the second resistance measurement circuit and the second voltage measurement circuit respectively. U a2 and U b2 , the resistance to be measured can be calculated by formula (4) R x resistance value.

[0024] Alternatively, a voltage ratio measuring device can be used to directly measure the ratio of the voltage on the first voltage measurement loop to the voltage on the first resistance measurement loop. K 1, and directly measure the ratio of the voltage on the second resistance measurement loop to the voltage on the second voltage measurement loop using a voltage ratio measurement device K 2, the resistance to be measured can be calculated by formula (5) R x resistance value.

[0025] It can be seen from formula (4) or formula (5) that the resistance to be measured is R x It has nothing to do with the two voltage-dividing sampling resistors and is independent of the DC voltage source. DC The output voltage of the voltage divider is also irrelevant. Therefore, the resistance drift of the voltage divider sampling resistor is related to the DC voltage source. DC The drift will no longer affect the measurement accuracy of high resistance.

[0026] The above-mentioned DC high-voltage high-resistance measurement circuit 100, by innovatively improving the existing voltage-dividing method circuit using an operational amplifier, introduces a linkage switch into the high-resistance measurement circuit and introduces a standard resistor, and the linkage switch is used to control two groups of voltage-resistance measurement circuits respectively, so that the resistance value of the resistor to be measured can be directly calculated from the resistance value of the standard resistor and the voltage on the two groups of voltage-resistance measurement circuits. In this measurement process, there is no need to use the resistance value of the voltage-dividing resistor and the sampling resistor, and it does not rely on the power supply, thereby avoiding the influence of the resistance drift of the voltage-dividing resistor and the sampling resistor and the drift of the power supply on the measurement accuracy of the high resistance, and can be used for accurate measurement of high resistance with a resistance range of more than 100 Ω, especially when measuring high resistance of 100 MΩ or GΩ or above, it has high measurement accuracy, and the measurement uncertainty can be controlled to within 50ppm.

[0027] In one embodiment, the DC high voltage high resistance measurement circuit 100 is configured to be connected to a voltage measurement device. In this embodiment, the DC high voltage high resistance measurement circuit 100 can also be connected to a voltage measurement device, and the voltage measurement device is used to measure the voltage on the first voltage measurement loop, the voltage on the first resistance measurement loop, the voltage on the second resistance measurement loop, and the voltage on the second voltage measurement loop, respectively.

[0028] In one embodiment, the DC high voltage high resistance measurement circuit 100 is configured to be connected to a voltage ratio measurement device. In this embodiment, the DC high voltage high resistance measurement circuit 100 can also be connected to a voltage ratio measurement device, which is used to measure the ratio of the voltage on the first voltage measurement loop to the first resistance measurement loop, and to measure the ratio of the voltage on the second resistance measurement loop to the second voltage measurement loop.

[0029] Specifically, the voltage ratio measurement device can be used to directly measure the ratio of the voltage on the first voltage measurement loop to the voltage on the first resistance measurement loop. K 1= U a1 / U b1 , and directly measure the ratio of the voltage on the second resistance measurement loop to the voltage on the second voltage measurement loop using a voltage ratio measurement device K 2= U a2 / Ub2 , the resistance to be measured can be directly calculated by formula (5) R x The voltage ratio measuring device can adopt various types of voltage ratio measuring circuits, chips or other types of measuring devices existing in the art, and the specific type can be selected according to the actual use needs.

[0030] In one embodiment, a DC high-voltage high-resistance measurement method is also provided, based on a DC high-voltage high-resistance measurement circuit, the DC high-voltage high-resistance measurement circuit is configured to be connected to a voltage measurement device, and the DC high-voltage high-resistance measurement circuit includes a DC voltage source, a standard resistor, a resistor to be measured, a linkage switch, a first operational amplifier, a second operational amplifier, a first voltage-dividing sampling resistor, and a second voltage-dividing sampling resistor. The negative end of the DC voltage source is grounded, the positive end of the DC voltage source is respectively connected to one end of the standard resistor and one end of the resistor to be measured, the other end of the standard resistor is connected to the inverting input end of the first operational amplifier or the second operational amplifier through the linkage switch, the other end of the resistor to be measured is connected to the inverting input end of the first operational amplifier or the second operational amplifier through the linkage switch, the in-phase input ends of the first operational amplifier and the second operational amplifier are both grounded, the first voltage-dividing sampling resistor is connected across the output end and the inverting input end of the first operational amplifier, and the second voltage-dividing sampling resistor is connected across the output end and the inverting input end of the second operational amplifier. When the linkage switch is closed in the first switch position, the standard resistor and the first voltage-dividing sampling resistor form a first voltage measurement circuit, and the resistor to be measured and the second voltage-dividing sampling resistor form a first resistance measurement circuit. When the linkage switch is closed in the second switch position, the resistor to be measured and the first voltage-dividing sampling resistor form a second resistance measurement circuit, and the standard resistor and the second voltage-dividing sampling resistor form a second voltage measurement circuit.

[0031] like Figure 4 As shown, the DC high voltage high resistance measurement method may include the following processing steps S10 to S18: S10, controlling the linkage switch to close at the first switch position, to construct a first voltage measurement loop and a first resistance measurement loop; S12, measuring the voltage on the first voltage measurement loop and the voltage on the first resistance measurement loop by a voltage measurement device; S14, controlling the linkage switch to close at the second switch position, to construct a second resistance measurement loop and a second voltage measurement loop; S16, measuring the voltage on the second resistance measurement loop and the voltage on the second voltage measurement loop by a voltage measurement device; S18, calculating the resistance value of the resistor to be measured according to the resistance value of the standard resistor, the voltage on the first voltage measurement loop, the voltage on the first resistance measurement loop, the voltage on the second resistance measurement loop, and the voltage on the second voltage measurement loop.

[0032] It can be understood that after constructing the DC high-voltage high-resistance measurement circuit, the linkage switch is closed in the first switch position to construct the first voltage measurement loop and the first resistance measurement loop, and then the voltages on the first voltage measurement loop and the first resistance measurement loop can be measured respectively. Then the linkage switch is closed in the second switch position to construct the second resistance measurement loop and the second voltage measurement loop, and then the voltages on the second resistance measurement loop and the second voltage measurement loop are measured respectively, and finally, the resistance value of the resistor to be measured is calculated based on the voltages on the above measurement loops and the resistance value of the standard resistor.

[0033] The above-mentioned DC high-voltage high-resistance measurement method, through innovative improvement of the existing voltage-dividing method circuit using an operational amplifier, introduces a linkage switch into the high-resistance measurement circuit and introduces a standard resistor, and the linkage switch is used to control two groups of voltage-resistance measurement circuits respectively, so that the resistance value of the resistor to be measured can be directly calculated from the resistance value of the standard resistor and the voltage on the two groups of voltage-resistance measurement circuits. In this measurement process, there is no need to use the resistance value of the voltage-dividing resistor and the sampling resistor, and it does not rely on the power supply, thereby avoiding the influence of the resistance drift of the voltage-dividing resistor and the sampling resistor and the drift of the power supply on the measurement accuracy of the high resistance, and can be used for accurate measurement of high resistance with a resistance range of more than 100 Ω, especially when measuring high resistance of 100 MΩ or GΩ or above, it has high measurement accuracy, and the measurement uncertainty can be controlled to within 50ppm.

[0034] In one embodiment, the linkage switch includes a linkage switch S 1 and switch S 2. Switch S 1 is connected to the inverting input terminal of the first operational amplifier, and the switch S 1The first fixed contact is connected to the other end of the standard resistor, and the switch S The second fixed contact of 1 is connected to the other end of the resistor to be measured. S The movable contact of 2 is connected to the inverting input terminal of the second operational amplifier, and the switch S 2 is connected to the other end of the resistor to be measured, and the switch S The second fixed contact of 2 is connected to the other end of the standard resistor.

[0035] In one embodiment, the DC high voltage high resistance measurement method is used to measure high resistance within the resistance range of 100Ω to 10000TΩ with high accuracy. It can be understood that when the DC high voltage high resistance measurement method is used to measure high resistance within the resistance range of 100Ω to 10000TΩ, its measurement accuracy can reach a high level and has a good practical application effect.

[0036] In one embodiment, another DC high-voltage high-resistance measurement method is also provided, based on a DC high-voltage high-resistance measurement circuit, which is configured to be connected to a voltage ratio measurement device, and the DC high-voltage high-resistance measurement circuit includes a DC voltage source, a standard resistor, a resistor to be measured, a linkage switch, a first operational amplifier, a second operational amplifier, a first voltage-dividing sampling resistor, and a second voltage-dividing sampling resistor. The negative end of the DC voltage source is grounded, and the positive end of the DC voltage source is respectively connected to one end of the standard resistor and one end of the resistor to be measured. The other end of the standard resistor is connected to the inverting input of the first operational amplifier or the second operational amplifier through the linkage switch, and the other end of the resistor to be measured is connected to the inverting input of the first operational amplifier or the second operational amplifier through the linkage switch, and the in-phase input of the first operational amplifier and the second operational amplifier are both grounded. The first voltage-dividing sampling resistor is connected between the output and the inverting input of the first operational amplifier, and the second voltage-dividing sampling resistor is connected between the output and the inverting input of the second operational amplifier. When the linkage switch is closed in the first switch position, the standard resistor and the first voltage-dividing sampling resistor form a first voltage measurement circuit, and the resistor to be measured and the second voltage-dividing sampling resistor form a first resistance measurement circuit. When the linkage switch is closed in the second switch position, the resistor to be measured and the first voltage-dividing sampling resistor form a second resistance measurement circuit, and the standard resistor and the second voltage-dividing sampling resistor form a second voltage measurement circuit.

[0037] like Figure 5 As shown, the DC high voltage high resistance measurement method may include the following processing steps S30 to S38: S30, controlling the linkage switch to close at the first switch position, to construct a first voltage measurement loop and a first resistance measurement loop; S32, measuring the ratio of the voltage on the first voltage measurement loop and the voltage on the first resistance measurement loop by a voltage ratio measurement device; S34, controlling the linkage switch to close at the second switch position, to construct a second resistance measurement loop and a second voltage measurement loop; S36, measuring the ratio of the voltage on the second resistance measurement loop and the voltage on the second voltage measurement loop by a voltage ratio measurement device; S38, calculating the resistance value of the resistor to be measured according to the resistance value of the standard resistor, the ratio of the first voltage measurement loop to the voltage on the first resistance measurement loop, and the ratio of the voltage on the second resistance measurement loop to the voltage on the second voltage measurement loop.

[0038] It can be understood that after constructing the DC high-voltage high-resistance measurement circuit, the linkage switch is closed in the first switch position to construct the first voltage measurement loop and the first resistance measurement loop, and then the ratio of the voltage on the first voltage measurement loop to the first resistance measurement loop can be directly measured. Then the linkage switch is closed in the second switch position to construct the second resistance measurement loop and the second voltage measurement loop, and then the ratio of the voltage on the second resistance measurement loop to the second voltage measurement loop is directly measured. Finally, the resistance of the resistor to be measured is calculated based on the ratio of the two voltages of the above-mentioned loop and the resistance of the standard resistor.

[0039] The above-mentioned DC high-voltage high-resistance measurement method, through innovative improvement of the existing voltage-dividing method circuit using an operational amplifier, introduces a linkage switch into the high-resistance measurement circuit and introduces a standard resistor, and the linkage switch is used to control two groups of voltage-resistance measurement circuits respectively, so that the resistance value of the resistor to be measured can be directly calculated from the resistance value of the standard resistor and the voltage on the two groups of voltage-resistance measurement circuits. In this measurement process, there is no need to use the resistance value of the voltage-dividing resistor and the sampling resistor, and it does not rely on the power supply, thereby avoiding the influence of the resistance drift of the voltage-dividing resistor and the sampling resistor and the drift of the power supply on the measurement accuracy of the high resistance, and can be used for accurate measurement of high resistance with a resistance range of more than 100 Ω, especially when measuring high resistance of 100 MΩ or GΩ or above, it has high measurement accuracy, and the measurement uncertainty can be controlled to within 50ppm.

[0040] In one embodiment, the linkage switch includes a linkage switch S 1 and switch S 2. Switch S 1 is connected to the inverting input terminal of the first operational amplifier, and the switch S 1The first fixed contact is connected to the other end of the standard resistor, and the switch S The second fixed contact of 1 is connected to the other end of the resistor to be measured. S The movable contact of 2 is connected to the inverting input terminal of the second operational amplifier, and the switch S 2 is connected to the other end of the resistor to be measured, and the switch S The second fixed contact of 2 is connected to the other end of the standard resistor.

[0041] In one embodiment, the DC high voltage high resistance measurement method is used to perform high-accuracy measurement of high resistance within a resistance range of 100Ω to 10000TΩ.

[0042] Those skilled in the art can understand that, according to the performance and parameters of existing electronic components such as DC voltage sources, standard resistors, operational amplifiers and analog-to-digital converters (ADCs), the DC high-voltage high-resistance measurement method described in this specification can be used for high-accuracy measurement of high resistances ranging from 100Ω to 10000TΩ. In particular, when measuring high resistances of 100MΩ or GΩ or above, the measurement uncertainty can be controlled to within 50ppm.

[0043] For the specific limitations of the above-mentioned DC high-voltage high-resistance measurement methods, please refer to the above-mentioned limitations on the DC high-voltage high-resistance measurement circuit 100, which will not be repeated here.

[0044] It should be understood that although Figure 4 and Figure 5 The steps in the flowchart are shown in sequence as indicated by the arrows, but the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of the steps, and the steps can be executed in other orders. Moreover, Figure 4 and Figure 5 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0045] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0046] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of protection of the invention. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A DC high voltage high resistance measurement circuit, characterized in that: It includes a DC voltage source, a standard resistor, a resistor to be measured, a linkage switch, a first operational amplifier, a second operational amplifier, a first voltage-dividing sampling resistor, and a second voltage-dividing sampling resistor; The negative end of the DC voltage source is grounded, the positive end of the DC voltage source is respectively connected to one end of the standard resistor and one end of the resistor to be measured, the other end of the standard resistor is connected to the inverting input end of the first operational amplifier or the second operational amplifier through the linkage switch, the other end of the resistor to be measured is connected to the inverting input end of the first operational amplifier or the second operational amplifier through the linkage switch, the non-inverting input ends of the first operational amplifier and the second operational amplifier are both grounded, the first voltage-dividing sampling resistor is connected between the output end and the inverting input end of the first operational amplifier, and the second voltage-dividing sampling resistor is connected between the output end and the inverting input end of the second operational amplifier; When the linkage switch is closed in the first switch position, the standard resistor and the first voltage-dividing sampling resistor form a first voltage measurement loop, and the resistor to be measured and the second voltage-dividing sampling resistor form a first resistance measurement loop; when the linkage switch is closed in the second switch position, the resistor to be measured and the first voltage-dividing sampling resistor form a second resistance measurement loop, and the standard resistor and the second voltage-dividing sampling resistor form a second voltage measurement loop; the standard resistor, the voltage on the first voltage measurement loop, the voltage on the first resistance measurement loop, the voltage on the second resistance measurement loop, and the voltage on the second voltage measurement loop are used to determine the resistance value of the resistor to be measured.

2. The DC high voltage high resistance measurement circuit according to claim 1, characterized in that: The linkage switch includes a linkage switch S 1 and switch S 2. The switch S 1 is connected to the inverting input terminal of the first operational amplifier, and the switch S 1 is connected to the other end of the standard resistor, the switch S The second fixed contact of 1 is connected to the other end of the resistor to be measured; The switch S 2 is connected to the inverting input terminal of the second operational amplifier, and the switch S 2 is connected to the other end of the resistor to be measured, and the switch S The second fixed contact of 2 is connected to the other end of the standard resistor.

3. The DC high voltage high resistance measurement circuit according to claim 1 or 2, characterized in that: The DC high-voltage high-resistance measurement circuit is configured to be connected to a voltage measurement device.

4. The DC high voltage high resistance measurement circuit according to claim 1 or 2, characterized in that: The DC high voltage high resistance measurement circuit is configured to be connected to a voltage ratio measurement device.

5. A DC high voltage high resistance measurement method, characterized in that: Based on a DC high-voltage high-resistance measurement circuit, the DC high-voltage high-resistance measurement circuit is configured to be connected to a voltage measurement device, and the DC high-voltage high-resistance measurement circuit includes a DC voltage source, a standard resistor, a resistor to be measured, a linkage switch, a first operational amplifier, a second operational amplifier, a first voltage-dividing sampling resistor, and a second voltage-dividing sampling resistor; The negative end of the DC voltage source is grounded, the positive end of the DC voltage source is respectively connected to one end of the standard resistor and one end of the resistor to be measured, the other end of the standard resistor is connected to the inverting input end of the first operational amplifier or the second operational amplifier through the linkage switch, the other end of the resistor to be measured is connected to the inverting input end of the first operational amplifier or the second operational amplifier through the linkage switch, the non-inverting input ends of the first operational amplifier and the second operational amplifier are both grounded, the first voltage-dividing sampling resistor is connected between the output end and the inverting input end of the first operational amplifier, and the second voltage-dividing sampling resistor is connected between the output end and the inverting input end of the second operational amplifier; When the linkage switch is closed in the first switch position, the standard resistor and the first voltage-dividing sampling resistor form a first voltage measurement loop, and the resistor to be measured and the second voltage-dividing sampling resistor form a first resistance measurement loop; when the linkage switch is closed in the second switch position, the resistor to be measured and the first voltage-dividing sampling resistor form a second resistance measurement loop, and the standard resistor and the second voltage-dividing sampling resistor form a second voltage measurement loop; The DC high voltage high resistance measurement method comprises the following steps: Control the linkage switch to close at a first switch position to construct the first voltage measurement loop and the first resistance measurement loop; Measuring the voltage on the first voltage measurement loop and the voltage on the first resistance measurement loop by the voltage measurement device; Controlling the linkage switch to close at a second switch position to construct the second resistance measurement loop and the second voltage measurement loop; Measuring the voltage on the second resistance measurement loop and the voltage on the second voltage measurement loop by the voltage measurement device; The resistance value of the resistor to be measured is calculated according to the resistance value of the standard resistor, the voltage on the first voltage measurement loop, the voltage on the first resistance measurement loop, the voltage on the second resistance measurement loop and the voltage on the second voltage measurement loop.

6. The DC high voltage high resistance measurement method according to claim 5, characterized in that: The linkage switch includes a linkage switch S 1 and switch S 2. The switch S 1 is connected to the inverting input terminal of the first operational amplifier, and the switch S 1 is connected to the other end of the standard resistor, the switch S The second fixed contact of 1 is connected to the other end of the resistor to be measured; The switch S 2 is connected to the inverting input terminal of the second operational amplifier, and the switch S 2 is connected to the other end of the resistor to be measured, and the switch S The second fixed contact of 2 is connected to the other end of the standard resistor.

7. The DC high voltage high resistance measurement method according to claim 5 or 6, characterized in that: The method is used to measure high resistance within the resistance range of 100Ω to 10000TΩ with high accuracy.

8. A DC high voltage high resistance measurement method, characterized in that: Based on a DC high-voltage high-resistance measurement circuit, the DC high-voltage high-resistance measurement circuit is configured to be connected to a voltage ratio measurement device, and the DC high-voltage high-resistance measurement circuit includes a DC voltage source, a standard resistor, a resistor to be measured, a linkage switch, a first operational amplifier, a second operational amplifier, a first voltage-dividing sampling resistor, and a second voltage-dividing sampling resistor; The negative end of the DC voltage source is grounded, the positive end of the DC voltage source is respectively connected to one end of the standard resistor and one end of the resistor to be measured, the other end of the standard resistor is connected to the inverting input end of the first operational amplifier or the second operational amplifier through the linkage switch, the other end of the resistor to be measured is connected to the inverting input end of the first operational amplifier or the second operational amplifier through the linkage switch, the non-inverting input ends of the first operational amplifier and the second operational amplifier are both grounded, the first voltage-dividing sampling resistor is connected between the output end and the inverting input end of the first operational amplifier, and the second voltage-dividing sampling resistor is connected between the output end and the inverting input end of the second operational amplifier; When the linkage switch is closed in the first switch position, the standard resistor and the first voltage-dividing sampling resistor form a first voltage measurement loop, and the resistor to be measured and the second voltage-dividing sampling resistor form a first resistance measurement loop; when the linkage switch is closed in the second switch position, the resistor to be measured and the first voltage-dividing sampling resistor form a second resistance measurement loop, and the standard resistor and the second voltage-dividing sampling resistor form a second voltage measurement loop; The DC high voltage high resistance measurement method comprises the following steps: Control the linkage switch to close at a first switch position to construct the first voltage measurement loop and the first resistance measurement loop; Measuring the ratio of the voltages on the first voltage measurement loop and the first resistance measurement loop by the voltage ratio measurement device; Controlling the linkage switch to close at a second switch position to construct the second resistance measurement loop and the second voltage measurement loop; Measuring the ratio of the voltage on the second resistance measurement loop to the voltage on the second voltage measurement loop by the voltage ratio measurement device; The resistance value of the resistor to be measured is calculated according to the resistance value of the standard resistor, the ratio of the voltage on the first voltage measurement loop and the first resistance measurement loop, and the ratio of the voltage on the second resistance measurement loop and the second voltage measurement loop.

9. The DC high voltage high resistance measurement method according to claim 8, characterized in that: The linkage switch includes a linkage switch S 1 and switch S 2. The switch S 1 is connected to the inverting input terminal of the first operational amplifier, and the switch S 1 is connected to the other end of the standard resistor, the switch S The second fixed contact of 1 is connected to the other end of the resistor to be measured; The switch S 2 is connected to the inverting input terminal of the second operational amplifier, and the switch S 2 is connected to the other end of the resistor to be measured, and the switch S The second fixed contact of 2 is connected to the other end of the standard resistor.

10. The DC high voltage high resistance measurement method according to claim 8 or 9, characterized in that: The method is used to measure high resistance within the resistance range of 100Ω to 10000TΩ with high accuracy.

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