CN107064644B - Conductor alternating current resistance measuring method and system - Google Patents
Conductor alternating current resistance measuring method and system Download PDFInfo
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- CN107064644B CN107064644B CN201710193930.7A CN201710193930A CN107064644B CN 107064644 B CN107064644 B CN 107064644B CN 201710193930 A CN201710193930 A CN 201710193930A CN 107064644 B CN107064644 B CN 107064644B
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- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/08—Measuring resistance by measuring both voltage and current
Abstract
The invention relates to a conductor alternating current resistance measuring method and system, which comprises an in-phase voltage acquisition device, an amplifying device, an automatic gain adjusting device, a phase shifter and an alternating current resistance output device, wherein the in-phase voltage acquisition device is connected with a wire to be measured and the phase shifter, the amplifying device is used for connecting the wire to be measured and the alternating current resistance output device, the phase shifter is connected with the automatic gain adjusting device, the automatic gain adjusting device is connected with the amplifying device, the alternating current resistance output device is connected with a common end of the in-phase voltage acquisition device and the phase shifter, the voltage drop of current flowing through the wire to be measured and the voltage drop of the wire to be measured are measured, the current flowing through the wire to be measured is converted into a first in-phase voltage, the voltage drop and the first in-phase voltage are processed through the phase shifter, the amplifying device and the automatic gain adjusting device, a voltage component in the voltage drop of the wire to be measured and the first in-phase voltage are calculated, and the alternating current resistance of the wire to be measured is obtained, no requirement is caused on a test environment, and the operation is convenient and the accuracy is high.
Description
Technical Field
The invention relates to the technical field of high-voltage equipment and tests, in particular to a conductor alternating current resistance measuring method and system.
Background
With the development of national economy, the power demand is increasing. In order to improve the current carrying capacity, the conductor cross-sectional areas of overhead wires and high voltage cables produced are becoming larger to meet the demand for power growth. For ac systems, the essence of increasing the current carrying capacity is to reduce the ac resistance of overhead lines and cables, which in addition to the dc resistance also includes the increase in resistance caused by the alternating electromagnetic field, the sum of which is the ac resistance. As conductors become larger in size, the uneven distribution of current along the conductor cross-section due to skin effect and proximity effect significantly increases their ac resistance. The ac resistance of the conductor is related to the conductor loss and capital investment in the transmission system, and thus needs to be accurately obtained. The wire is affected by magnetic losses due to steel core hysteresis in addition to skin and proximity effects and is related to magnetic field strength (related to current carrying capacity). In addition, both the conductor portion of the wire and the core portion of the load bearing wire are complex multi-layer, multi-strand wire structures. The ac resistance of the wire is affected by factors such as the outside environment, air temperature and sunlight, in addition to the structure of the wire.
Conventional ac resistance measurement uses test techniques that can be divided into two categories: the thermal measurement method and the electrical measurement method can make absolute and relative measurement, and each measurement can be used for steady state and transient state conditions, but the thermal measurement method needs to put a wire to be measured into a constant temperature environment, otherwise, the accuracy is still unknown, and the heat insulation and measurement are difficult; the electric measuring method needs a plurality of instruments, uses a power meter, a potentiometer for measurement and the like, and adopts the principle that the voltage and the current of a measuring wire at the power frequency and the maximum design use temperature are measured, and a four-point measuring method is adopted, so that a skilled operator and a long time are required to ensure the measurement and the precision. The traditional alternating current resistor has complex measuring process, difficulty in ensuring precision and low operational convenience and accuracy.
Disclosure of Invention
Based on this, it is necessary to provide a conductor alternating-current resistance measurement method and system with high operability convenience and accuracy in view of the above-described problems.
The conductor alternating current resistance measuring system comprises an in-phase voltage acquisition device, an amplifying device, an automatic gain adjusting device, a phase shifter and an alternating current resistance output device, wherein the in-phase voltage acquisition device is connected with the phase shifter and is also used for being connected with a wire to be measured, the amplifying device is connected with the alternating current resistance output device and is also used for being connected with the wire to be measured, the phase shifter is connected with the automatic gain adjusting device, the automatic gain adjusting device is connected with the amplifying device, the alternating current resistance output device is connected with a common end of the in-phase voltage acquisition device and the phase shifter,
the in-phase voltage acquisition device is used for converting the measured current flowing through the wire to be measured into a first in-phase voltage and transmitting the first in-phase voltage to the phase shifter and the alternating current resistor output device;
the phase shifter is used for shifting the phase of the received first in-phase voltage to obtain a phase-shifted voltage, and transmitting the phase-shifted voltage to the automatic gain adjusting device;
the automatic gain adjusting device obtains gain voltage according to the received phase-shift voltage and sends the gain voltage to the amplifying device;
the amplifying device is used for measuring the voltage drop of the wire to be tested, receiving the gain voltage sent by the automatic gain adjusting device, calculating the voltage component according to the voltage drop and the gain voltage, and sending the voltage component to the alternating current resistance output device;
and the alternating current resistance output device calculates and obtains the alternating current resistance of the wire to be tested according to the received first in-phase voltage and the voltage component and outputs the alternating current resistance.
A conductor alternating current resistance measuring method comprises the following steps:
the in-phase voltage acquisition device measures the current flowing through the wire to be tested, converts the current flowing through the wire to be tested into a first in-phase voltage, and sends the first in-phase voltage to the phase shifter and the alternating current resistor output device;
the phase shifter shifts the phase of the first in-phase voltage according to the received first in-phase voltage to obtain a phase-shifted voltage, and sends the phase-shifted voltage to an automatic gain adjusting device;
the automatic gain adjusting device obtains gain voltage according to the received phase-shift voltage and sends the gain voltage to the amplifying device;
the amplifying device measures the voltage drop of the wire to be tested, receives the gain voltage sent by the automatic gain adjusting device, calculates a voltage component according to the gain voltage and the voltage drop, and sends the voltage component to the alternating current resistance output device;
and the alternating current resistance output device calculates and obtains the alternating current resistance of the wire to be tested according to the received first in-phase voltage and the voltage component and outputs the alternating current resistance.
According to the conductor alternating current resistance measuring system and method, the current flowing in the wire to be measured and the voltage drop of the wire to be measured are measured at the same time, the current flowing in the wire to be measured is converted into the first same-phase voltage, the voltage drop and the first same-phase voltage are processed through the phase shifter, the amplifying device and the automatic gain adjusting device to obtain the voltage component, the alternating current resistance of the wire to be measured is obtained through calculation of the voltage component in the voltage drop of the wire to be measured and the first same-phase voltage, no requirement is made on the test environment, and the operation is convenient and accuracy is high.
Drawings
FIG. 1 is a block diagram of an AC resistance measuring system according to one embodiment;
FIG. 2 is a phasor diagram of a loop signal of a wire under test;
FIG. 3 is a block diagram of an alternate current resistance measurement system according to another embodiment;
FIG. 4 is a block diagram of an alternate current resistance measurement system according to another embodiment;
FIG. 5 is a block diagram of an alternate current resistance measurement system according to another embodiment;
FIG. 6 is a flowchart of an alternating current resistance measurement method according to an embodiment.
Detailed Description
In one embodiment, as shown in fig. 1, a conductor ac resistance measurement system includes an in-phase voltage acquisition device 110, an amplifying device 120, an automatic gain adjustment device 130, a phase shifter 140 and an ac resistance output device 150, where the in-phase voltage acquisition device 110 is connected to the phase shifter 140 and is further connected to a wire 200 to be measured, the amplifying device 120 is connected to the ac resistance output device 150 and is further connected to the wire 200 to be measured, the phase shifter 140 is connected to the automatic gain adjustment device 130, the automatic gain adjustment device 130 is connected to the amplifying device 120, the ac resistance output device 150 is connected to a common terminal of the in-phase voltage acquisition device 110 and the phase shifter 140, and the in-phase voltage acquisition device 110 is configured to convert a measured current flowing through the wire 200 to be measured into a first in-phase voltage and send the first in-phase voltage to the phase shifter 140 and the ac resistance output device 150; the phase shifter 140 is configured to shift the phase of the received first in-phase voltage to obtain a phase-shifted voltage, and send the phase-shifted voltage to the automatic gain adjustment device 130, where the automatic gain adjustment device 130 obtains a gain voltage according to the received phase-shifted voltage and sends the gain voltage to the amplifying device 120; the amplifying device 120 is configured to measure a voltage drop of the wire 200 to be measured, receive the gain voltage sent by the automatic gain adjustment device 130, calculate a voltage component according to the voltage drop and the gain voltage, and send the voltage component to the ac resistor output device 150; the ac resistance output device 150 calculates the ac resistance of the wire 200 to be tested according to the received first in-phase voltage and the voltage component and outputs the ac resistance.
Specifically, as shown in fig. 2, the in-phase voltage acquisition device 110 is configured to measure the measured current flowing through the wire 200
Conversion to the first in-phase voltage->
First in-phase voltage->
Phase-shifted by 90 degrees in phase shifter 140 to a phase-shifted voltage +.>
Phase-shift voltage->
Amplified by the automatic gain adjusting device 130 to gain voltage +.>
The amplifying device 120 is used for measuring the wire 200 to be measuredVoltage drop, converting the voltage drop of the wire 200 to be measured into a second in-phase voltage +>
The wire 200 to be tested is considered as a series connection of a pure resistor and an inductor, through which a current signal is flowing +.>
In this case, a resistive voltage component +_ is generated in the wire 200>
And inductive voltage component>
Phase-shift voltage->
With a second in-phase voltage->
Inductive voltage component->
In-phase, when gain voltage->
With a second in-phase voltage->
Inductive voltage component->
When equal, the amplifying device 120 outputs a resistive voltage component proportional to the voltage drop of the alternating current resistor of the wire 200 to be tested and in phase
Finally by resistive voltage component->
And a first in-phase voltage->
And calculating and outputting the alternating current resistance r of the wire 200 to be tested.
Specifically, in the conductor ac resistance measurement system, the current flowing in the wire 200 to be measured and the voltage drop of the wire 200 to be measured are measured at the same time, the current flowing in the wire 200 to be measured is converted into the first in-phase voltage, the voltage drop and the first in-phase voltage are processed through the phase shifter 140, the amplifying device 120 and the automatic gain adjusting device 130 to obtain the voltage component, and the ac resistance of the wire 200 to be measured is obtained by calculating the ratio of the voltage component in the voltage drop of the wire 200 to be measured and the first in-phase voltage, so that the requirement on the test environment is avoided, and the operation is convenient and the accuracy is high.
In one embodiment, the in-phase voltage obtaining device 110 includes a current sensor 112 and a resistor 114, one end of the current sensor 112 is connected to one end of the resistor 114, the other end of the current sensor 112 and the other end of the resistor 114 are grounded, and a common end of the current sensor 112 and the resistor 114 is connected to the phase shifter 140.
Specifically, the type of in-phase voltage acquisition device 110 is not unique, and in the present embodiment, the current transformer 112 senses a current signal flowing through the wire 200 to be measured
Current transformer 112 and pure resistor 114R s Connected in series in a loop, resistor 114R s Is grounded at one end of resistor 114R s The other end voltage of (2) is>
The output signal of the in-phase voltage obtaining means 110 is therefore AND +.>
First in-phase voltage ∈>
In one embodiment, the amplifying device 120 includes a differential amplifier 122 and a differential amplifier 124, wherein an input end of the differential amplifier 122 is connected to the wire 200 to be tested, an output end of the differential amplifier 122 is connected to a non-inverting input end of the differential amplifier 124, an inverting input end of the differential amplifier 124 is also connected to an output end of the automatic gain adjusting device 130, and an output end of the differential amplifier 124 is connected to an input end of the ac resistor output device 150; the differential amplifier 122 is configured to measure the voltage drop of the wire 200 to be measured, convert the voltage drop of the wire 200 to be measured into a second in-phase voltage, and send the second in-phase voltage to the differential amplifier 124; the differential amplifier 124 is configured to obtain a voltage component according to the received second in-phase voltage and the gain voltage, and send the voltage component to the ac resistor output device 150.
Specifically, the input end of the differential amplifier 122 is connected to two terminals of the wire 200 to be measured for measuring the voltage drop of the wire 200 to be measured, so that the input signal of the differential amplifier 122 is the voltage drop of the wire 200 to be measured, and the level conversion is realized, because the wire 200 to be measured is considered to be a series connection of a pure resistor and an inductor, and a current signal flows
In this case, a resistive voltage component +_ is generated in the wire 200>
And inductive voltage component>
The two voltage drops together form the input of the differential amplifier 122, which differential amplifier 122 amplifies the input signal according to a certain amplification factor to obtain a second in-phase voltage +.>
The second in-phase voltage of the output signal>
The phase of the input signal is the same, and the magnitude is changed; the differential amplifier 124 obtains a voltage linearly proportional to the voltage drop across the wire 200 to be measured and a voltage linearly proportional to the inductive voltage drop across the wire 200 to be measured, orthogonal to the wire current, and outputs a voltage in phase with the wire current and linearly proportional to the resistive voltage drop across the wire.
In one embodiment, as shown in fig. 3, the automatic gain adjustment device 130 is further configured to connect the common terminal of the amplifying device 120 and the ac resistor output device 150, and the amplifying device 120 is further configured to send a voltage component to the automatic gain adjustment device 130, update the voltage component according to the received first gain voltage and the voltage drop, obtain an updated voltage component, and send the updated voltage component to the ac resistor output device 150; the automatic gain adjustment device 130 is further configured to perform an operation according to the received voltage component and the phase-shifted voltage, adjust the gain voltage to obtain a first gain voltage, and send the first gain voltage to the amplifying device 120.
Specifically, the automatic gain adjustment device 130 is connected to the common terminal of the differential amplifier 124 of the amplifying device 120 and the ac resistor output device 150.
Specifically, the amplifying device 120 sends the output voltage component to the automatic gain adjusting device 130, and the automatic gain adjusting device 130 determines whether the voltage component contains the gain voltage or not
In-phase component, if the voltage component contains a value equal to +.>
The automatic gain adjusting device 130 calculates and adjusts the gain G according to the received voltage component and the phase-shifted voltage to obtain a first gain voltage so as to enable the first gain voltage to be equal to +.>
Inductive voltage component->
Equal, cancel out
The amplifying means 120 outputs the updated voltage component +.>
And sent to the ac resistor output device 150, finally through the updated voltage component +.>
And a first in-phase voltage->
The ac resistance r of the wire 200 to be measured is calculated and output, the received voltage component is judged by the automatic gain adjustment device 130, and the inductive voltage component in the voltage is offset, so that the voltage component is updated, the pure resistive voltage component is finally obtained, the ac resistance r of the wire 200 to be measured is accurately calculated, and the accuracy is effectively improved.
In one embodiment, as shown in fig. 4, the automatic gain adjustment device 130 includes an operation device 132 and an automatic gain control amplifier 134, wherein an input end of the operation device 132 is connected to an output end of the amplifying device 120, an input end of the operation device 132 is also connected to a common end of the phase shifter 140 and the automatic gain control amplifier 134, an output end of the operation device 132 is connected to an input end of the automatic gain control amplifier 134, an output end of the automatic gain control amplifier 134 is connected to an input end of the amplifying device 120, and the operation device 132 performs operation according to the received voltage component and the phase-shifted voltage to obtain a control signal, and sends the control signal to the automatic gain control amplifier 134; the automatic gain control amplifier 134 adjusts the gain according to the received control signal, obtains a gain voltage according to the adjusted gain and the phase-shift voltage, and transmits the gain voltage to the amplifying device 120.
Specifically, the input terminal of the operation device 132 is connected to the output terminal of the differential amplifier 124 of the amplifying device 120, and the output terminal of the automatic gain adjustment amplifier is connected to the inverting input terminal of the differential amplifier 124 of the amplifying device 120.
Specifically, the computing device 132 is configured to perform a computation based on the received voltage component and the phase-shifted voltage, determine whether there is still a component in the inductive direction in the voltage component, and if there is still a component in the inductive direction, adjust the gain G, which is a variable whose value is determined by the phase-shifted voltage, according to the computation result
Is determined in conjunction with the output of the operation means 132 such that the first gain voltage +.>
And->
And the pure resistive voltage component is finally obtained, the alternating current resistance r of the wire 200 to be measured is accurately calculated, and the accuracy is effectively improved.
In one embodiment, the operation device 132 includes a multiplier 1322 and an integrator 1324, the input end of the multiplier 1322 is connected to the output end of the amplifying device 120, the output end of the multiplier 1322 is connected to the input end of the integrator 1324, the output end of the integrator 1324 is connected to the input end of the automatic gain control amplifier 134, the multiplier 1322 performs product operation according to the received voltage component and the phase-shifted voltage to obtain an operation value, and sends the operation value to the integrator 1324; the integrator 1324 integrates the received operation value to obtain a control signal, and sends the control signal to the automatic gain control amplifier 134.
Specifically, the input terminal of the multiplier 1322 is connected to the common terminal of the differential amplifier 124 of the amplifying device 120 and the ac resistor output device 150.
Specifically, the computing device 132 obtains and integrates the inductive component in the output of the differential amplifier 124 corresponding to the voltage drop across the wire 200 to be tested, and uses the cascade of the multiplier 1322 and the integrator 1324 to obtain the control signal for the automatic gain control amplifier 134, the determination is made by the multiplier 1322 if the gain voltage is to be obtained
And->
There is still a difference in the voltage component +.>
There will be a component of the inductive direction, then the voltage component +.>
And phase shift voltage->
The product operation by the multiplier 1322 is not zero, the output of the multiplier 1322 is not zero, the integral operation by the integrator 1324 is not zero, the feedback signal enters the automatic gain control amplifier 134, and the automatic gain control amplifier 134 receives the output signal of the integrator 1324 and the phase-shift voltage>
Adjusting the gain G to obtain a first gain voltage so that the first gain voltage is equal to +.>
Inductive component->
And the voltage component is updated equally, the pure resistive voltage component is finally obtained, the alternating current resistance r of the wire 200 to be measured is accurately calculated, and the accuracy is effectively improved.
Further, the initial value of the gain G of the automatic gain control amplifier 134 is set to a constant value within the gain range when
Less than/>
The inductive component in (i.e.)>
The output signal from the differential amplifier 124 contains an AND
The in-phase components are combined with +.>
The value input to the integrator 1324 after the product operation is a positive value, and the signal integrated by the integrator 1324 is input to the control end of the automatic gain control amplifier 134, so that the gain of the automatic gain control amplifier 134 is reduced; conversely->
Is greater than->
The inductive component in (i.e.)>
The output signal from the differential amplifier 124 contains an AND/OR>
The inverted components are multiplied by multipliers 1322 and +.>
The value input to the integrator 1324 after the product operation is a negative value, and the signal integrated by the integrator 1324 is input to the control terminal of the automatic gain control amplifier 134, so that the gain of the automatic gain control amplifier 134 increases, and the system balance is achieved. The output of differential amplifier 124 contains only the updated voltage component, i.e., resistive, if the system is balanced, i.e., at this timeThe voltage component, then the pure resistive voltage signal is operated on in multiplier 1322>
Phase-shifted voltage in phase with the pure inductive voltage signal>
That is to say +.>
And->
The phase difference is 90 degrees, the operation result of the multiplier 1322 is 0, that is, the multiplier 1322 has no output signal, the integrator 1324 has no input signal, and the automatic gain control amplifier 134 reaches an equilibrium state at this time, so as to obtain a pure resistive voltage component of the wire 200 to be measured, accurately calculate the ac resistance r of the wire 200 to be measured, and effectively improve accuracy.
In one embodiment, the ac resistive output device 150 is a divider.
Specifically, the type of divider is not unique, and the divider receives the voltage component output by the amplifying device 120 or the updated voltage component
And a phase-shifted voltage in phase with the inductive voltage component +.>
The two are divided by a divider to obtain the alternating current resistance of the wire 200 to be tested.
In a more detailed embodiment, as shown in FIG. 5, a current transformer senses a current signal flowing through a wire 200 under test
Current transformer and resistor R s Connected in series to form a loop with the output voltage of the loop being the first in-phase currentPressure->
Differential amplifier 122 measures the voltage drop of wire 200 to be measured, and converts the voltage drop of wire 200 to be measured into a second in-phase voltage +.>
First in-phase voltage->
Phase-shifted by 90 degrees to form a phase-shifted voltage +.>
And is in phase with the second in-phase voltage->
Inductive voltage component in (a)
In-phase, phase-shifted voltage->
Gain voltage is obtained after G gain amplification>
When gain voltage +>
And inductive component->
When equal, the differential amplifier 124 outputs a resistive voltage component, which is a voltage component proportional to the voltage drop of the ac resistor of the wire 200 to be tested and in phase>
If the voltage component->
There is also a gain voltage->
In the case of the in-phase component, the voltage component and the phase-shifted voltage are multiplied and integrated to adjust the gain G to cancel +.>
The inductive voltage component in (2) is updated to obtain an updated voltage component, and finally the updated voltage component is used for +.>
And a first in-phase voltage->
And calculating and outputting the alternating current resistance r of the wire 200 to be tested.
According to the conductor alternating current resistance measuring system, the current flowing in the wire 200 to be measured and the voltage drop of the wire 200 to be measured are measured at the same time, the current flowing in the wire 200 to be measured is converted into the first same-phase voltage, the voltage drop and the first same-phase voltage are processed through the phase shifter 140, the amplifying device 120 and the automatic gain adjusting device 130, the updated voltage component, namely the resistive voltage component, is obtained, the alternating current resistance of the wire 200 to be measured is obtained through the ratio of the resistive voltage component in the voltage drop of the wire 200 to be measured and the first same-phase voltage, no requirement is required for a test environment, and the conductor alternating current resistance measuring system is convenient to operate, high in speed and accuracy, and meets the test requirements of research institutions and manufacturers.
In one embodiment, as shown in fig. 6, a method for measuring alternating current resistance of a conductor includes the steps of:
step S110: the in-phase voltage acquisition device measures the current flowing through the wire to be tested, converts the current flowing through the wire to be tested into a first in-phase voltage, and sends the first in-phase voltage to the phase shifter and the alternating current resistor output device.
Specifically, the in-phase voltage acquisition device comprises a current sensor and a resistor, wherein the current sensor is used for sensing current flowing through a wire to be tested.
Step S120: the phase shifter shifts the first in-phase voltage according to the received first in-phase voltage to obtain a phase-shifted voltage, and sends the phase-shifted voltage to the automatic gain adjusting device.
Specifically, the phase shifter receives a first in-phase voltage, phase-shifts the first in-phase voltage by 90 degrees to obtain a phase-shifted voltage, and sends the phase-shifted voltage to the automatic gain adjustment device. Because the first in-phase voltage lags behind the inductive voltage component by 90 degrees, the first in-phase voltage needs to be shifted by 90 degrees to be changed into a phase-shifting voltage, so that the phase-shifting voltage is in phase with the inductive voltage component in the second in-phase voltage.
Step S130: the automatic gain adjusting device obtains gain voltage according to the received phase-shift voltage and sends the gain voltage to the amplifying device.
Step S140: the amplifying device is used for measuring the voltage drop of the wire to be measured, receiving the gain voltage sent by the automatic gain adjusting device, calculating according to the gain voltage and the voltage drop to obtain a voltage component, and sending the voltage component to the alternating current resistance output device. In this embodiment, the automatic gain adjustment device is further used for connecting the common terminal of the amplifying device and the ac resistor output device, and step S140 includes steps 142 to 148.
Step 142: and calculating a voltage component according to the gain voltage and the voltage drop.
Specifically, the amplifying device comprises a differential amplifier and a differential amplifier, wherein the differential amplifier measures the voltage drop of a wire to be tested, converts the voltage drop of the wire to be tested into a second in-phase voltage, and sends the second in-phase voltage to the differential amplifier; the differential amplifier obtains a voltage component from the received second in-phase voltage and the gain voltage.
Step 144: the amplifying means sends the voltage component to the automatic gain adjusting means.
Step 146: the automatic gain adjusting device calculates according to the received voltage component and the phase-shift voltage, adjusts the gain voltage to obtain a first gain voltage, and sends the first gain voltage to the amplifying device.
Specifically, the automatic gain adjusting device comprises an operation device and an automatic gain control amplifier, wherein the operation device performs operation according to the received voltage component and the phase-shift voltage to obtain a control signal, and sends the control signal to the automatic gain control amplifier; the automatic gain control amplifier adjusts the gain according to the received control signal, obtains a first gain voltage according to the adjusted gain and the phase-shift voltage, and sends the first gain voltage to the amplifying device, and further sends the first gain voltage to the differential amplifier of the amplifying device.
Step 148: the amplifying device updates the voltage component according to the received first gain voltage and voltage drop, and sends the updated voltage component to the alternating current resistance output device.
Specifically, the amplifying device includes a differential amplifier and a differential amplifier, the differential amplifier updates the voltage component according to the received first gain voltage and the second in-phase voltage, so as to obtain an updated voltage component, namely a resistive voltage component, and sends the updated voltage component to the ac resistor output device, so that the ac resistor r of the wire 200 to be tested is accurately calculated, and accuracy is effectively improved.
Step S150: and the alternating current resistance output device calculates and obtains the alternating current resistance of the wire to be tested according to the received first in-phase voltage and the voltage component and outputs the alternating current resistance.
According to the conductor alternating current resistance measuring method, the current flowing in the wire to be measured and the voltage drop of the wire to be measured are measured at the same time, the current flowing in the wire to be measured is converted into the first same-phase voltage, the voltage drop and the first same-phase voltage are processed through the phase shifter, the amplifying device and the automatic gain adjusting device, the updated voltage component is obtained, the alternating current resistance of the wire to be measured is obtained through the ratio of the updated voltage component in the voltage drop of the wire to be measured and the first same-phase voltage, no requirement is met for the test environment, and the method is convenient, rapid and high in accuracy, and meets the test requirements of research institutions and manufacturers.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (8)
1. The conductor alternating current resistance measuring system is characterized by comprising an in-phase voltage acquisition device, an amplifying device, an automatic gain adjusting device, a phase shifter and an alternating current resistance output device, wherein the in-phase voltage acquisition device is connected with the phase shifter and is also used for being connected with a wire to be measured, the amplifying device is connected with the alternating current resistance output device and is also used for being connected with the wire to be measured, the phase shifter is connected with the automatic gain adjusting device, the automatic gain adjusting device is connected with the amplifying device, the alternating current resistance output device is connected with a public end of the in-phase voltage acquisition device and the phase shifter,
the in-phase voltage acquisition device is used for converting the measured current flowing through the wire to be measured into a first in-phase voltage and transmitting the first in-phase voltage to the phase shifter and the alternating current resistor output device;
the phase shifter is used for shifting the phase of the received first in-phase voltage to obtain a phase-shifted voltage, and transmitting the phase-shifted voltage to the automatic gain adjusting device;
the automatic gain adjusting device obtains gain voltage according to the received phase-shift voltage and sends the gain voltage to the amplifying device;
the amplifying device is used for measuring the voltage drop of the wire to be measured, receiving the gain voltage sent by the automatic gain adjusting device, calculating to obtain a voltage component according to the gain voltage and the voltage drop, and sending the voltage component to the automatic gain adjusting device;
the automatic gain adjusting device calculates according to the received voltage component and the phase-shifting voltage, adjusts the gain voltage to obtain a first gain voltage and sends the first gain voltage to the amplifying device;
the amplifying device updates the voltage component according to the received first gain voltage and the voltage drop, and sends the updated voltage component to the alternating current resistor output device;
and the alternating current resistance output device calculates and obtains the alternating current resistance of the wire to be tested according to the received first in-phase voltage and the voltage component and outputs the alternating current resistance.
2. The system of claim 1, wherein the in-phase voltage acquisition device comprises a current sensor and a resistor, one end of the current sensor is connected to one end of the resistor, the other end of the current sensor and the other end of the resistor are grounded, and a common end of the current sensor and the resistor is connected to the phase shifter.
3. The conductor ac resistance measurement system according to claim 1, wherein the amplifying device comprises a differential amplifier and a differential amplifier, wherein an input end of the differential amplifier is connected with the wire to be measured, an output end of the differential amplifier is connected with a non-inverting input end of the differential amplifier, an inverting input end of the differential amplifier is also connected with an output end of the automatic gain adjustment device, and an output end of the differential amplifier is connected with an input end of the ac resistance output device;
the differential amplifier is used for measuring the voltage drop of the wire to be measured, converting the voltage drop of the wire to be measured into a second in-phase voltage and transmitting the second in-phase voltage to the differential amplifier;
the differential amplifier is used for obtaining a voltage component according to the received second in-phase voltage and the gain voltage and sending the voltage component to the alternating current resistance output device.
4. The system of claim 1, wherein said automatic gain adjustment means is further adapted to connect said amplifying means to a common terminal of said ac resistor output means,
the amplifying means is further for transmitting the voltage component to the automatic gain adjustment means; updating the voltage component according to the received first gain voltage and the voltage drop, and sending the updated voltage component to the alternating current resistance output device;
the automatic gain adjusting device is also used for carrying out operation according to the received voltage component and the phase-shifting voltage, adjusting the gain voltage to obtain the first gain voltage and sending the first gain voltage to the amplifying device.
5. The system of claim 4, wherein the automatic gain control device comprises an operation device and an automatic gain control amplifier, wherein an input end of the operation device is connected to an output end of the amplifying device, an input end of the operation device is further connected to a common end of the phase shifter and the automatic gain control amplifier, an output end of the operation device is connected to an input end of the automatic gain control amplifier, an output end of the automatic gain control amplifier is connected to an input end of the amplifying device,
the operation device performs operation according to the received voltage component and the phase-shift voltage to obtain a control signal, and sends the control signal to the automatic gain control amplifier;
the automatic gain control amplifier adjusts the gain according to the received control signal, obtains a first gain voltage according to the adjusted gain and the phase-shift voltage, and sends the first gain voltage to the amplifying device.
6. The system of claim 5, wherein the computing device comprises a multiplier and an integrator, the input end of the multiplier is connected with the output end of the amplifying device, the output end of the multiplier is connected with the input end of the integrator, the output end of the integrator is connected with the input end of the automatic gain control amplifier,
the multiplier performs product operation according to the received voltage component and the phase-shifting voltage to obtain an operation value, and sends the operation value to the integrator;
the integrator integrates the received operation value to obtain a control signal, and sends the control signal to the automatic gain control amplifier.
7. The conductor ac resistance measurement system of claim 1 wherein the ac resistance output device is a divider.
8. The conductor ac resistance measurement system of claim 1 wherein the phase shifter is specifically configured to:
and receiving the first in-phase voltage, shifting the first in-phase voltage by 90 degrees in phase, obtaining a phase-shifting voltage, and transmitting the phase-shifting voltage to an automatic gain adjusting device.
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| CN109061311A (en) * | 2018-09-10 | 2018-12-21 | 哈尔滨理工大学 | A kind of conductor AC resistance automatic testing equipment based on FPGA with stream than device electric bridge |
| CN110865577B (en) * | 2019-11-22 | 2021-03-19 | 北京东方计量测试研究所 | Digital sampling method and device for alternating current resistance calibration |
| CN111308206B (en) * | 2020-02-21 | 2022-04-15 | 苏州华兴源创科技股份有限公司 | Impedance detection device and detection method thereof |
| CN111722137B (en) * | 2020-07-01 | 2023-05-12 | 重庆西南集成电路设计有限责任公司 | Micro-resistance test system based on four-wire method and digital anti-interference circuit |
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