JP2020144026A - Insulated voltage measurement device - Google Patents

Abstract

To provide an insulated voltage measurement device capable of highly accurately measuring a voltage of a measurement target conductor even in a state where another conductor is disposed near the voltage measurement target conductor.SOLUTION: A detection probe disposed on an outer surface of a voltage measurement target detects, by means of a current, a measurement target voltage component of a conductor of the voltage measurement target including a voltage noise component caused by a conductor of a nearby wire existing near the voltage measurement target. A voltage noise detection electrode disposed near the conductor of the nearby wire detects the voltage noise component including the measurement target voltage component as a current. In a current input arithmetic section, the current detected by the detection probe is inputted via a shield line and converted into a voltage, and the current detected by the voltage noise detection electrode is inputted via a shield line and converted into a voltage. In a correction voltage arithmetic section, the voltage noise component is removed from a detection voltage in which the conductor measurement target voltage component and the voltage noise component are mixed, converted into the voltage by the current input arithmetic section and a measured voltage of the conductor of the voltage measurement target is obtained.SELECTED DRAWING: Figure 1

Description

The present invention relates to an insulated voltage measuring device that measures a voltage applied to an object for voltage measurement.

As a device for measuring the voltage applied to the object to be measured with voltage, there is a non-contact voltage detection device that measures the voltage applied to the conductor of the insulated wire in a non-contact manner (see, for example, Patent Document 1). This has a first electrode on the electric wire side and a second electrode for voltage detection in the insulating member, and the second electrode is arranged at a distance from a part of the first electrode, and the outer surface of the insulating coating of the electric wire is arranged. It has a flexible detection probe that can be wound in close contact with the electrode.

In this detection probe, the capacitance Ca of the auxiliary capacitor portion formed between the first electrode and the second electrode is formed sufficiently smaller than the capacitance Cs between the conductor of the electric wire and the first electrode, and the detection probe is formed. A detection capacitor and a voltage detection circuit are connected to the auxiliary capacitor portion of the above, and the AC voltage V applied to the conductor of the electric wire is measured.

That is, since the input voltage Vin of the voltage detection circuit is Vin≈ (Ca / Cin) · V (Cin is the capacitance of the detection capacitor and V is the voltage to be measured), the voltage to be measured (AC voltage of the wire conductor). Since V is represented by the ratio of the capacitance Ca of the auxiliary capacitor portion to the capacitance C of the detection capacitor, it is not affected by the capacitance Cs between the conductor of the electric wire and the first electrode. , The voltage measurement of the AC voltage of the electric wire conductor can be performed with high accuracy.

Further, the applicant, as Japanese Patent Application No. 2018-569706 (hereinafter referred to as the earlier application), suppresses the influence of the floating capacitance of the electrode of the detection probe, and even if the type of the wire to be measured is different, the AC voltage of the conductor We have developed and applied for a patent for an isolated voltage measuring device that can measure the voltage of the above with high accuracy. In this insulated voltage measuring device, a conductor-side electrode arranged close to the outer surface of a voltage measurement object and an output-side electrode having a smaller area than the conductor-side electrode and arranged facing the conductor-side electrode at a distance from each other. A voltage composed of an I / V conversion circuit (current-voltage conversion circuit) provided with a detection probe provided between the conductor-side electrode and the output-side electrode and having a dielectric having a large insulation resistance and a small dielectric constant. The detection unit inputs the current of the output side electrode to obtain an output voltage Vout proportional to the current of the output side electrode.

Japanese Unexamined Patent Publication No. 2012-163394

However, in Patent Document 1 and the previous application, the voltage of the conductor of an insulatingly coated electric wire as a voltage measurement object is measured through capacitance. Therefore, if there is another conductor in the vicinity, Through the capacitance generated between the conductor to be measured and the measurement electrode of the detection probe, the voltage component of another nearby conductor is mixed as a voltage noise component, resulting in an error, and it is possible to perform highly accurate voltage measurement of the conductor. Can not.

In addition, when the conductor to be measured for voltage is an insulated wire, the diameter of the conductor and the thickness of the insulation coating of the conductor change depending on the type of wire. Therefore, if the type of wire to be measured is different, the voltage is to be measured. The capacitance between the conductor and the measuring electrode will change. Therefore, it is necessary to take measures when the types of electric wires to be measured for voltage are different.

FIG. 8 is an explanatory diagram of the insulated voltage measuring device of Patent Document 1. 8 (a) is a schematic configuration diagram thereof, FIG. 8 (b) is an equivalent circuit of FIG. 8 (a), and FIG. 8 (c) is a floating capacitance of the first electrode Cs1 and a floating capacitance of the second electrode 15. It is an equivalent circuit considering the capacitance Ca1. As shown in FIG. 8, when measuring the AC voltage applied to the conductor 12 (hereinafter referred to as the measurement target conductor 12) of the voltage measurement target electric wire 11, the detection probe 13 is placed on the outer surface of the insulating coating of the measurement target electric wire 11. Install. The detection probe 13 is formed on a large-area first electrode 14 on the side of the electric wire to be measured 11 and a part of the first electrode 14 in a flexible insulating member that can be wound in close contact with the outer surface of the insulating coating. It has a second electrode 15 having a small area for detecting voltage to be opposed to each other. Then, a large-capacity detection capacitor Cin is connected to the subsequent stage of the second electrode 15, and the voltage of the detection capacitor Cin is measured by the voltage detection circuit 16 to measure the AC voltage applied to the measurement target conductor 12.

As shown in FIG. 8B, the capacitance Cs between the conductor of the electric wire and the first electrode 14 and the capacitance of the auxiliary capacitor portion formed between the first electrode 14 and the second electrode 15 The combined capacitance Cp with Ca is connected in series with the detection capacitor Cin. The detection capacitor Cin is a detection capacitor in which the stray capacitance of the electric wire 11 to be measured is negligible. As shown in FIG. 8C, the stray capacitance Cs1 of the first electrode 14 and the stray capacitance Cs1 of the second electrode 15 Even if the stray capacitance Ca1 is present, it is not affected by these stray capacitances Cs1 and Ca1.

That is, the current from the second electrode 15 having a low capacitance is converted into the voltage Vin of the large-capacity detection capacitor Cin so that the stray capacitance of the cable can be ignored. From this, since the current from the second electrode 15 having a low capacitance is very small and the capacitance of the large-capacity capacitor Cin is large, the input voltage Vin of the voltage detection circuit becomes very small, which is affected by noise. Easy to receive.

Therefore, the applicant has developed the insulated voltage measuring device of the previous application. FIG. 9 is an explanatory diagram of the insulated voltage measuring device of the previous application. In FIG. 9, a test voltage V1 is applied from the AC power supply 17 to the measurement target conductor 12 coated with the insulating coating 26, and the AC voltage V1 applied from the AC power supply 17 is the voltage of the measurement target conductor 12. Become. In measuring the voltage of the conductor 12 to be measured, the detection probe 13 is attached to the outer surface of the insulating coating 26 of the electric wire 11 to be measured. The detection probe 13 is arranged so as to face the conductor side electrode 18 which is arranged in contact with the outer surface of the insulating coating 26 of the electric wire 11 to be measured and the conductor side electrode 18 which has a smaller area than the conductor side electrode 18 and is spaced from each other. A dielectric 20 is provided between the output side electrode 19 and the conductor side electrode 18 and the output side electrode 19.

A capacitance C12 is generated between the measurement target conductor 12 and the output side electrode 19 by the insulating coating 26 and the dielectric 20 of the measurement target conductor 12. Due to the capacitance C12, the voltage V1 of the conductor to be measured generates a current I1, and this current I1 is input to the voltage detection unit 21. The voltage detection unit 21 is formed of an I / V conversion circuit having a small impedance. Further, the shield wire 25 is arranged from the immediate vicinity of the output side electrode 19 to the negative input terminal of the operational amplifier 22 of the voltage detection unit 21 to reduce the influence of the capacitance of the wiring from the output side electrode 19 to the voltage detection unit 21. ing.

The current I1 from the output side electrode 19 is input to the negative terminal of the operational amplifier 22 of the voltage detection unit 21 through the core wire of the shield wire 25, and the output voltage Vout of the voltage detection unit 21 becomes Vout = −I1 · Z. This is because the positive terminal of the operational amplifier 22 is grounded (GND), and the operational amplifier 22 operates so that the negative terminal has the same potential as the positive terminal. As a result, an output voltage Vout proportional to the current I1 from the output side electrode 19 is obtained. Since the voltage V1 of the conductor 12 to be measured and the output voltage Vout of the measurement result have a proportional relationship with a specific proportional coefficient, the voltage V1 of the conductor 12 to be measured can be obtained from the output voltage Vout of the measurement result.

FIG. 10 shows FIG. 9 in the case where there is a conductor 29x of the first neighboring electric wire 28x coated with the insulating coating 26x (hereinafter, referred to as the first neighboring conductor 29x) in the vicinity of the measurement target conductor 12 coated with the insulating coating 26. It is explanatory drawing of the shown insulation type voltage measuring apparatus. In FIG. 10, the measurement target conductor 12 coated with the insulating coating 26 and the first neighboring conductor 29x coated with the insulating coating 26x are shown as viewed from above.

A test voltage Vx is applied from the AC power supply 17x to the first neighboring conductor 29x coated with the insulating coating 26x, and the AC voltage Vx applied from the AC power supply 17x becomes the voltage of the first neighboring conductor 29x.

When the first neighboring conductor 29x is located in the vicinity of the measurement target conductor 12, a capacitance Cx1 is generated between the first neighboring conductor 29x and the output side electrode 19 of the detection probe 13. The voltage Vx of the first neighboring conductor 29x generates a current Ix due to the capacitance Cx1 between the first neighboring conductor 29x and the output side electrode 19. Therefore, a current (I1 + Ix) in which the current I1 from the conductor 12 to be measured and the current Ix from the neighboring conductor 29 are mixed flows through the core wire of the shield wire 25, and the current flows through the voltage detection unit 21. (I1 + Ix) is input. Therefore, the output voltage Vout of the measurement result has an error of the current Ix from the neighboring conductor 29.

That is, the insulated voltage measuring device of the previous application is effective when another first neighboring conductor 29x does not exist in the vicinity of the measurement target conductor 12, but the first neighboring conductor 29x is in the vicinity of the measurement target conductor 12. If there is, an error of the current Ix from the first neighboring conductor 29x occurs in the output voltage Vout of the measurement result.

Since the electric circuit transmits electrical energy by having conductors on the outward path and the return path, there is always a return conductor in the vicinity of the conductor to be measured. Further, when the conductor 12 to be measured is related to electric power, there are many three phases, and the wiring of the electric circuit is often three. In addition, various types of single-phase and three-phase wiring are mixed in the switchboard, which is often used for measurement.

As described above, in Patent Document 1 and earlier applications, if there is a conductor different from the measurement target conductor in the vicinity, it occurs between the measurement target conductor and the output side electrode of the detection probe which is the measurement electrode. Through the capacitance, the voltage component of another conductor in the vicinity is mixed, resulting in an error of the output voltage Vout of the measurement result, and it is not possible to measure the voltage of the conductor with high accuracy.

An object of the present invention is to provide an insulated voltage measuring device capable of measuring the voltage of a conductor to be measured with high accuracy even when another conductor is arranged in the vicinity of the conductor to be measured.

The insulated voltage measuring device according to the invention of claim 1 is the voltage measuring object which is arranged on the outer surface of the voltage measuring object and contains a voltage noise component due to a conductor of a neighboring electric wire existing in the vicinity of the voltage measuring object. A detection probe that detects the voltage component to be measured of the conductor with a current, a voltage noise detection electrode that is arranged near the conductor of the neighboring electric wire and detects the voltage noise component including the voltage component to be measured as a current, and the detection. The current input calculation unit that inputs the current detected by the probe through the shield wire and converts it into a voltage, and also inputs the current detected by the voltage noise detection electrode through the shield wire and converts it into a voltage, and the current input. A correction voltage calculation unit that removes the voltage noise component from the detection voltage in which the conductor measurement target voltage component converted into a voltage by the calculation unit and the voltage noise component are mixed to obtain the measurement voltage of the conductor of the voltage measurement target. It is characterized by having.

The insulated voltage measuring device according to the invention of claim 2 is the voltage measuring object which is arranged on the outer surface of the voltage measuring object and contains a voltage noise component due to a conductor of a neighboring electric wire existing in the vicinity of the voltage measuring object. The detection probe that detects the voltage component to be measured of the conductor by the current and the shield wire that takes out the current detected by the detection probe are further shielded as a double shield wire, and the shield wire is connected to the outer shield portion of the double shield wire. The voltage noise batch detection unit, which is formed by exposing the end of the shield portion to the detection probe side and detects the voltage noise component including the measurement target voltage component as a current, and the current detected by the detection probe are described. The core wire of the shielded wire is input to the current-voltage conversion circuit to convert it into a voltage, and the current detected by the voltage noise batch detection unit is input to the current-voltage conversion circuit via the shielded portion of the shielded wire, which can be regarded as a grounded state. From the current input calculation unit that converts the current detected by the voltage noise batch detection unit into voltage, and the detection voltage in which the conductor measurement target voltage component converted into voltage by the current input calculation unit and the voltage noise component are mixed. It is characterized by including a correction voltage calculation unit that removes the voltage noise component and obtains the measured voltage of the conductor of the voltage measurement object.

According to the invention of claim 1, the measurement of the conductor of the voltage measurement object including the voltage noise component by the conductor of the neighboring electric wire existing in the vicinity of the voltage measurement object by the detection probe arranged on the outer surface of the voltage measurement object. The target voltage component is detected by the current, the voltage noise component including the measurement target voltage component is detected by the current by the voltage noise detection electrode provided near the conductor of the neighboring electric wire, and the current and voltage noise detected by the detection probe are detected. The current detected by the electrodes is converted to voltage by the current input calculation unit, and the correction voltage calculation unit converts voltage noise from the detection voltage in which the conductor measurement target voltage component and voltage noise component converted to voltage by the current input calculation unit are mixed. Since the component is removed and the measured voltage of the conductor of the voltage measurement target is obtained, the voltage of the measurement target conductor can be measured with high accuracy even when another conductor is arranged in the vicinity of the measurement target conductor.

According to the invention of claim 2, the shield wire that takes out the current detected by the detection probe is further shielded as a double shielded wire, and the end portion of the shielded portion of the shielded wire is detected from the outer shield portion of the double shielded wire. The voltage noise component including the voltage component to be measured is detected by the current by the voltage noise batch detection unit formed by exposing it to the side. Therefore, the current detected by the detection probe or the voltage noise batch detection unit can be input to the current input calculation unit regardless of the capacitance of the shielded wire or the double shielded wire or the change in capacitance due to routing.

Since the voltage noise batch detection unit is formed in a circumferential structure by exposing the end of the shielded part of the shielded wire to the detection probe side, the voltage noise due to the conductors of all the neighboring electric wires existing in the vicinity of the voltage measurement object is formed. Ingredients can be detected. Since the current input calculation unit inputs the current detected by the voltage noise batch detection unit to the current-voltage conversion circuit via the shield unit of the shield wire that can be regarded as the grounded state, it is the same as when the shield wire is grounded. Then, the correction voltage calculation unit removes the voltage noise component from the detection voltage in which the conductor measurement target voltage component and the voltage noise component converted into voltage by the current input calculation unit are mixed, and obtains the measurement voltage of the conductor of the voltage measurement target. Therefore, the voltage of the measurement target conductor can be measured with high accuracy even when another conductor is arranged in the vicinity of the voltage measurement target conductor.

The block diagram which shows an example of the insulation type voltage measuring apparatus which concerns on 1st Embodiment of this invention. The circuit diagram of the equivalent circuit of the insulation type voltage detection apparatus shown in FIG. The block diagram which shows another example of the insulation type voltage measuring apparatus which concerns on 1st Embodiment of this invention. The block diagram which shows another other example of the insulation type voltage measuring apparatus which concerns on 1st Embodiment of this invention. The block diagram which shows an example of the insulation type voltage measuring apparatus which concerns on 2nd Embodiment of this invention. The circuit diagram of the equivalent circuit of the insulation type voltage detection apparatus shown in FIG. The block diagram which shows another example of the insulation type voltage measuring apparatus which concerns on 2nd Embodiment of this invention. Explanatory drawing of the insulated voltage measuring apparatus of Patent Document 1. Explanatory drawing of the insulated voltage measuring apparatus of the previous application. Explanatory drawing of the insulated voltage measuring apparatus shown in FIG. 9 when there is a conductor of a neighboring electric wire in the vicinity of the conductor of the electric wire to be measured.

Hereinafter, embodiments of the present invention will be described. FIG. 1 is a configuration diagram showing an example of an insulated voltage measuring device according to the first embodiment of the present invention. FIG. 1 shows a case where two neighboring conductors 29, that is, a first neighboring conductor 29x and a second neighboring conductor 29y exist in the vicinity of the measurement target conductor 12. In the case of electric power, there are many three phases, so one of the three phases is set as the measurement target conductor 12, and the case where the first neighboring conductor 29x and the second neighboring conductor 29y are located on both sides of the measurement target conductor 12 Shown.

A test voltage V1 is applied from the AC power supply 17 to the measurement target conductor 12 coated with the insulating coating 26, and the AC voltage V1 applied from the AC power supply 17 becomes the voltage of the measurement target conductor 12. On the other hand, a test voltage Vx is applied from the AC power supply 17x to the first neighboring conductor 29x coated with the insulating coating 26x, and the AC voltage Vx applied from the AC power supply 17x is the voltage of the first neighboring conductor 29x. Become. Similarly, a test voltage Vy is applied to the second neighboring conductor 29y coated with the insulating coating 26y from the AC power supply 17y, and the AC voltage Vy applied from the AC power supply 17y is the voltage of the second neighboring conductor 29y. It becomes.

In measuring the voltage of the conductor 12 to be measured, the detection probe 13 is arranged on the outer surface of the insulating coating 26 of the electric wire 11 to be measured. The detection probe 13 has a dielectric 20A and an output side electrode 19 arranged in contact with the outer surface of the insulating coating 26 of the electric wire 11 to be measured.

A capacitance Cm is generated between the measurement target conductor 12 and the output side electrode 19 by the insulating coating 26 of the measurement target conductor 12 and the dielectric 20A. Due to this capacitance Cm, the voltage V1 of the conductor 12 to be measured generates a current I1. The current I1 is the current of the voltage component to be measured from the conductor 12 to be measured. Further, a capacitance Cx1 is generated between the first neighboring conductor 29x and the output side electrode 19 of the detection probe 13. The voltage Vx of the first neighboring conductor 29x generates a current Ix due to the capacitance Cx1 between the first neighboring conductor 29x and the output side electrode 19. The current Ix is the current of the voltage noise component from the first neighboring conductor 29x. Similarly, a capacitance Cy1 is generated between the second neighboring conductor 29y and the output side electrode 19 of the detection probe 13. The voltage Vy of the second neighboring conductor 29y generates a current Iy due to the capacitance Cy1 between the first neighboring conductor 29x and the output side electrode 19. The current Iy is the current of the voltage noise component from the second neighboring conductor 29y.

Therefore, in the core wire of the shielded wire 25, in addition to the current I1 from the conductor 12 to be measured, the current Ix from the first neighboring conductor 29x and the current Iy from the second neighboring conductor 29y are mixed in the current Im (= I1). + Ix + Iy) will flow, and the current Im is input to the voltage detection unit 21 of the current input calculation unit 30. That is, the current Im includes the current I1 of the voltage component to be measured of the conductor 12 to be measured, the current Ix of the voltage noise component due to the first neighboring conductor 29x existing in the vicinity of the conductor 12 to be measured, and the second neighboring conductor 29y. The current Iy of the voltage noise component is included. This current Im is input to the negative terminal of the operational amplifier 22 of the voltage detection unit 21 of the current input calculation unit 30 through the core wire of the shield wire 25, and the output voltage Voutm of the voltage detection unit 21 becomes Voutm = −Im · Z. .. As a result, the voltage detection unit 21 of the current input calculation unit 30 obtains a detection voltage Voutm proportional to the current Im. The detection voltage Voutm of the measurement target conductor 12 includes a voltage noise component for the current (Ix + Iy) from the neighboring conductor 29 in addition to the measurement target voltage component for the current I1 from the measurement target conductor 12. ..

Next, a voltage noise detection electrode 27 is provided in the vicinity of the two first neighboring electric wires 28x and the second neighboring electric wire 28y. FIG. 1 shows a case where two voltage noise detection electrodes 27x and 27y are provided, and shows a case where the two voltage noise detection electrodes 27x and 27y are attached to the dielectric 20A of the detection probe 13. , Another dielectric may be provided instead of the dielectric 20A, and voltage noise detection electrodes 27x and 27y may be provided on the other dielectric, respectively. In that case, it is desirable that another dielectric to which the voltage noise detection electrodes 27x and 27y are attached has a structure integrally attached to the detection probe 13. This is because the voltage noise detection electrode 27x is located at a position where the voltage of the first neighboring conductor 29x of the first neighboring electric wire 28x can be detected when the detection probe 13 is arranged on the measurement target electric wire 11, and the voltage noise detecting electrode 27y This is because the voltage of the second neighboring conductor 29y of the second neighboring electric wire 28y is located at a position where the voltage can be detected.

Here, the output side electrode 19 of the measurement target conductor 12 is arranged as close as possible to the measurement target conductor 12, and the voltage noise detection electrodes 27x, 27y for detecting the voltages Vx and Vy of the first neighboring conductor 29x and the second neighboring conductor 29y. Is arranged at a position away from the conductor 12 to be measured.

The voltage noise detection electrode 27x is the total current Ix1 (= Ix2 + Ix3) of the current Ix2 flowing in the capacitance Cx2 between the first neighboring conductor 29x and the current Ix3 flowing in the capacitance Cx3 between the conductors 12 to be measured. Is detected and input to the voltage detection unit 21x of the current input calculation unit 30 as the detection current Ix1 (= Ix2 + Ix3) of the voltage noise detection electrode 27x. The current Ix2 is a voltage noise component from the first neighboring conductor 29x, and the current Ix3 is a current of the voltage component to be measured from the measurement target conductor 12. That is, the current Ix1 includes the current Ix2 of the voltage noise component from the first neighboring conductor 29x and the current Ix3 of the voltage component to be measured from the measurement target conductor 12. This current Ix1 is input to the negative terminal of the operational amplifier 22x of the voltage detection unit 21x of the current input calculation unit 30 through the core wire of the shield wire 25, and the output voltage Voutx of the voltage detection unit 21x becomes Voutx = -Ix1 · Z. .. As a result, the voltage detection unit 21x of the current input calculation unit 30 obtains a detection voltage Voutx proportional to the current Ix1 (= Ix2 + Ix3).

The detection voltage Voutx of the voltage noise detection electrode 27x has a capacitance Cx3 between the current Ix2 (current of the voltage noise component) flowing in the capacitance Cx2 between the first neighboring conductor 29x and the conductor 12 to be measured. It is a mixed voltage of the voltage component to be measured and the voltage noise component by the flowing current Ix3 (current of the voltage component to be measured).

Similarly, the voltage noise detection electrode 27y is the total current Iy1 of the current Iy2 flowing in the capacitance Cy2 between the second neighboring conductor 29y and the current Iy3 flowing in the capacitance Cy3 between the measurement target conductor 12 ( = Iy2 + Iy3) is detected and input to the voltage detection unit 21y of the current input calculation unit 30 as the detection current Iy1 (= Iy2 + Iy3) of the voltage noise detection electrode 27y. The current Iy2 is a voltage noise component from the second neighboring conductor 29y, and the current Iy3 is a current of the voltage component to be measured from the measurement target conductor 12. That is, the current Iy1 includes the current Iy2 of the voltage noise component from the second neighboring conductor 29y and the current Iy3 of the voltage component to be measured from the measurement target conductor 12. The current Ix1 and the current Iy1 are input to the negative terminal of the operational amplifier 22y of the voltage detection unit 21y of the current input calculation unit 30 through the core wire of the shield wire 25, and the output voltage Vouty of the voltage detection unit 21y is Vouty = −Iy1 · Z. It becomes. As a result, the voltage detection unit 21y of the current input calculation unit 30 obtains a detection voltage Vouty proportional to the current Iy1 (= Iy2 + Iy3).

The detection voltage Vouty of the voltage noise detection electrode 27y is set to the capacitance Cy3 between the current Iy2 (current of the voltage noise component) flowing in the capacitance Cy2 between the second neighboring conductor 29y and the conductor 12 to be measured. It is a mixed voltage of the voltage component to be measured and the voltage noise component due to the flowing current Iy3 (current of the voltage component to be measured).

The detection voltage Voutm of the voltage detection unit 21 of the current input calculation unit 30, the detection voltage Voutx of the voltage detection unit 21x of the current input calculation unit 30, and the detection voltage Vouty of the voltage detection unit 21y of the current input calculation unit 30 are corrected voltage calculations. It is input to the unit 31. In the correction voltage calculation unit 31, the voltage noise component corresponding to the current (Ix + Iy) from the neighboring conductor 29 from the detected voltage Voutm of the measurement target conductor 12, and the current Ix2 from the detected voltage Voutx of the voltage noise detection electrode 27x to the neighboring conductor 29x. The measured voltage of the measurement target conductor 12 obtained by removing the voltage noise component of the minute voltage noise component and the voltage noise component of the voltage noise detection electrode 27y from the detection voltage Vouty of the voltage noise detection electrode 27y for the current Iy2 minutes from the neighboring conductor 29y is output as the output voltage Vout. That is, the correction voltage calculation unit 31 obtains the measurement voltage value of the measurement target voltage V1 by the calculation formula shown in (1) below and outputs it as the output voltage Vout.

Vout = K1 × (Voutm- (K2 × Voutx + K3 × Vouty))… (1)
In the equation (1), K1 is a coefficient for taking the correspondence between the output voltage Vout and the voltage (measurement target voltage) V1 of the measurement target conductor 12 so that it becomes 1V at 100 Vrms. K2 is a coefficient such that the voltage noise component contained in Voutx is at the same level as the voltage noise component contained in Voutm, and K3 is a coefficient at which the voltage noise component contained in Vouty is at the same level as the voltage noise component contained in Voutm. It is such a coefficient. As a result, the voltage noise component due to the neighboring voltages Vx and Vy can be removed, and the value of the measurement target voltage V1 can be obtained with high accuracy.

As described above, the output side electrode 19 of the measurement target conductor 12 is arranged as close as possible to the measurement target conductor 12, and the voltage noise detection electrode 27x for detecting the voltages Vx and Vy of the first neighboring conductor 29x and the second neighboring conductor 29y. , 27y are arranged at positions away from the conductor 12 to be measured, so that the following equations (2a), (2b), and (2c) are established.

Cm> Cx1, Cy1 ... (2a)
Cm> Cx2, Cy2 ... (2b)
Cm> Cy3, Cx3 ... (2c)
However,
Cm: Capacitance between the conductor 12 to be measured and the output side electrode 19 Cx1: Capacitance between the first neighboring conductor 29x and the output side electrode 19 Cy1: The second neighboring conductor 29y and the output side electrode 19 Capacitance Cx2 between: Capacitance between the first neighboring conductor 29x and the voltage noise detection electrode 27x Cy2: Capacitance between the second neighboring conductor 29y and the voltage noise detection electrode 27y Cx3: Measurement target Capacitance Cy3 between the conductor 12 and the voltage noise detection electrode 27x: Capacitance between the conductor 12 to be measured and the voltage noise detection electrode 27y.

FIG. 2 is a circuit diagram of an equivalent circuit of the isolated voltage detection device shown in FIG. In addition to the capacitance Cm between the measurement target conductor 12 and the output side electrode 19 of the measurement target conductor 12, the capacitance Cx1 between the first neighboring conductor 29x and the static electricity between the second neighboring conductor 29y The capacitance Cy1 and the like are generated. Therefore, the currents Ix and Iy due to the components of the neighboring voltages Vx and Vy are mixed in the current I1 due to the components of the voltage V1 of the conductor 12 to be measured. Further, a current Ix1 is generated by a component of the voltage V1 of the conductor 12 to be measured and a component of the neighboring voltage Vx, and similarly, a current Iy1 is generated by a component of the voltage V1 of the conductor 12 to be measured and a component of the neighboring voltage Vy.

The current I1 in FIG. 2 is a current (current from the output side electrode 19) flowing through the capacitance Cm due to the voltage V1 of the conductor to be measured, and is a current of the voltage component to be measured. The current Ix is a current flowing through the capacitance Cx1 due to the voltage Vx of the first neighboring conductor 29x, and is a current of a voltage noise component. The current Iy is a current flowing through the capacitance Cy1 due to the voltage Vy of the second neighboring conductor 29y, and is a current of a voltage noise component. The current Ix1 is the current flowing through the capacitance Cx2 due to the voltage Vx of the first neighboring conductor 29x (current of the voltage noise component) and the current flowing through the capacitance Cx3 by the voltage V1 of the conductor to be measured (current of the voltage component to be measured). Is the total current of. The current Iy1 is the current flowing through the capacitance Cy2 due to the voltage Vy of the second neighboring conductor 29y (current of the voltage noise component) and the current flowing through the capacitance Cy3 by the voltage V1 of the conductor to be measured (current of the voltage component to be measured). Is the total current of.

As shown in the above equations (2a) to (2c), the capacitance Cm between the measurement target conductor 12 and the output side electrode 19 has other capacitances Cx1, Cy1, Cx2, Cy2, Cy3, Cx3. Since it is larger, the current I1 from the output side electrode 19 contains more components of the measurement target voltage V1 than the current Ix1 and the current Iy1.

Further, from the positional relationship between the detection target conductor 12, the first neighboring conductor 29x, the second neighboring conductor 29y, the detection probe 13 (output side electrode 19), and the voltage noise detection electrodes 27x, 27y, the following (3a), ( 3b) Equation holds.

Cx2> Cx1 ... (3a)
Cy2> Cy1 ... (3b)
Therefore, the current Ix1 from the voltage noise detection electrode 27x contains a large amount of components of the neighboring voltage Vx. The current Iy1 from the voltage noise detection electrode 27y contains a large amount of components of the neighboring voltage Vy.

Further, the voltage noise detection electrode 27x has a capacitance Cx3 between the measurement target conductor 12 and the measurement target conductor 12, but the capacitance Cx3 is smaller than the capacitance Cm between the measurement target conductor 12 and the output side electrode 19. In the current Ix1 flowing from the voltage noise detection electrode 27x, the component of the measurement target voltage V1 is smaller than the current I1 from the output side electrode 19. Similarly, the voltage noise detection electrode 27y has a capacitance Cy3 between the measurement target conductor 12 and the measurement target conductor 12, but the voltage noise detection is smaller than the capacitance Cm between the measurement target conductor 12 and the output side electrode 19. In the current Iy1 flowing from the electrode 27y, the component of the measurement target voltage V1 is smaller than the current I1 from the output side electrode 19.

Then, as described above, in the current input calculation unit 30, the detection voltage Voutm proportional to the current I1 from the output side electrode 19, the detection voltage Voutx proportional to the current Ix1 flowing from the voltage noise detection electrode 27x, and the voltage noise detection electrode The detection voltage Vouty proportional to the current Iy1 flowing from 27y is obtained and output to the correction voltage calculation unit 31.

In the correction voltage calculation unit 31, the voltage noise component corresponding to the current (Ix + Iy) from the neighboring conductor 29 from the detected voltage Voutm of the measurement target conductor 12, and the current Ix2 from the detected voltage Voutx of the voltage noise detection electrode 27x to the neighboring conductor 29x. The measured voltage of the measurement target conductor 12 obtained by removing the voltage noise component of the minute voltage noise component and the voltage noise component of the voltage noise detection electrode 27y from the detection voltage Vouty of the voltage noise detection electrode 27y for the current Iy2 minutes from the neighboring conductor 29y is output as the output voltage Vout.

According to the first embodiment, voltage noise detection electrodes 27x and 27y are provided for neighboring electric wires 28x and 28y existing in the vicinity of the voltage measurement object 11, and the voltage of the neighboring conductors 29x and 29y is the detection voltage of the measurement target conductor 12. Detects voltage noise components that affect. Then, the current input calculation unit 30 obtains the detection voltage Voutm of the measurement target conductor 12 detected by the detection probe 13 and the detection voltages Voutx and Vouty detected by the voltage noise detection electrodes 27x and 27y, and these detection voltages Voutm, Since the measured voltage of the measurement target conductor 12 obtained by removing the voltage noise components due to the neighboring voltages Vx and Vy from Voutx and Vouty is obtained as the output voltage Vout, measurement is performed even when the neighboring conductors 29x and 29y are arranged in the vicinity of the measurement target conductor 12. The voltage of the target conductor 12 can be measured with high accuracy.

Depending on the arrangement position of the electrodes and the areas of the voltage noise detection electrode 27 and the output side electrode 19, the equations (3a) and (3b) may not hold, but even in that case, the structure (2a) holds. If there is, since the current Im contains many components of the voltage to be measured V1, the I / V conversion coefficients K2 and K3 that convert the voltage noise detection currents Iy1 and Ix1 into Vouty and Voutx are changed or the correction voltage is corrected. By adjusting K2 and K3 of the calculation formula of the formula (1) in the calculation unit, the detection voltage Vout which is the component output of the measurement target voltage V1 can be obtained.

In the above description, the case of the two neighboring conductors 29x and 29y has been described, but the same can be applied to the case where m voltage noise detection electrodes 27 are provided for the n neighboring conductors 29. Each of the m voltage noise detection electrodes 27 detects the voltage component to be measured of the conductor 12 to be measured and the voltage noise from all n neighboring conductors 29, but detects the voltage noise from the nearest neighboring conductor 29. It will be mainly detected.

Further, in the above description, the detection probe 13 has a dielectric 20A and an output side electrode 19 arranged in contact with the outer surface of the insulating coating 26 of the electric wire 11 to be measured, which is shown in FIG. As described above, the conductor side electrode 18 may be provided on the measurement target electric wire 11 side of the dielectric 20A. As a result, the conductor side electrode 18 is arranged in contact with the outer surface of the insulating coating 26 of the electric wire 11 to be measured. The conductor-side electrode 18 is larger than the output-side electrode 19, and is formed so that the dielectric 20A is located between the conductor-side electrode 18 and the output-side electrode 19. By providing the conductor-side electrode 18, it is possible to reduce the influence of the wire diameter (diameter of the thickness of the insulating coating) of the wire 11 to be measured and the diameter of the conductor. Since the other configurations are the same as those of the insulated voltage measuring device shown in FIG. 1, the same elements are designated by the same reference numerals and duplicate description will be omitted.

Further, in the above description, as shown in FIGS. 1 and 3, the dielectric 20A of the detection probe 13 is brought into contact with the outer surface of the insulating coating 26 of the measurement target electric wire 11, and the detection probe 13 is arranged on the measurement target electric wire 11. However, as shown in FIG. 4, as shown in FIG. 4, the distance between the detection probe 13 and the dielectric 20A is maintained so as not to come into contact with the outer surface of the insulating coating 26 of the electric wire 11 to be measured. It is also possible to arrange it. FIG. 4 shows a case where the output side electrode 19 is embedded in the dielectric 20A. Similarly, with respect to the other example shown in FIG. 3, it is possible to arrange the detection probe 13 and the dielectric 20A at intervals so as not to come into contact with the outer surface of the insulating coating 26 of the electric wire 11 to be measured. is there.

Next, the second embodiment of the present invention will be described. FIG. 5 is a configuration diagram showing an example of an insulated voltage measuring device according to a second embodiment of the present invention. In the second embodiment, the shield wire 25 for extracting the current from the output side electrode 19 of the detection probe 13 is further shielded as the double shield wire 32 as compared with the first embodiment shown in FIG. The end of the shield portion (inner shield portion of the double shield wire 32) of the shield wire 25 exposed from the outer shield portion of 32 to the detection probe 13 side is used as the voltage noise batch detection portion 33. The voltage noise batch detection unit 33 can collectively detect the voltage noise components of each of the plurality of proximity conductors 29, and even if the positional relationship between the measurement target electric wire 11 and the proximity electric wire 28 is not constant, the neighborhood electric wire 28 can be used for general purposes. It is possible to reduce the influence of. The same elements as those in FIG. 1 are designated by the same reference numerals, and redundant description will be omitted.

In FIG. 5, the double shielded wire 32 has a double shielded structure, and the end of the shielded portion of the shielded wire 25 exposed from the outer shielded portion of the double shielded wire 32 is used as the voltage noise batch detection unit 33. .. Since the voltage noise batch detection unit 33 is an end portion of the shield portion of the shield wire 25 exposed from the outer shield of the double shield wire 32, the structure is a circumferential structure and the cross section is circular. Therefore, since the electric field from the neighboring conductor 29 can be captured regardless of the positional relationship between the neighboring conductors 29x and 29y, the voltage noise component in which the voltage of the neighboring conductor 19 affects the detection voltage of the measurement target conductor 12 can be detected. ..

Further, since the voltage noise batch detection unit 33 is located in the direction perpendicular to the output side electrode 19 that detects the voltage V1 of the measurement target conductor 12, the measurement target conductor 12 of the voltage noise batch detection unit 33 On the other hand, the capacitance Cxy becomes smaller. Nevertheless, since the voltage noise batch detection unit 33 is close to the output side electrode 19 in terms of distance, it is possible to detect an equivalent component with respect to the electric field component given to the output side electrode 19 by the neighboring conductor 29. That is, the voltage noise component in which the voltage of the neighboring conductor 19 affects the detection voltage of the conductor 12 to be measured can be detected with high accuracy.

A capacitance Cm is generated between the measurement target conductor 12 and the output side electrode 19 by the insulating coating 26 and the dielectric 20 of the measurement target conductor 12. Due to this capacitance Cm, the voltage V1 of the conductor 12 to be measured generates a current I1. The current I1 is the current of the voltage component to be measured from the conductor 12 to be measured. Further, a capacitance Cx1 is generated between the first neighboring conductor 29x and the output side electrode 19 of the detection probe 13. The voltage Vx of the first neighboring conductor 29x produces a current Ix due to this capacitance Cx1. The current Ix is the current of the voltage noise component from the first neighboring conductor 29x. Similarly, a capacitance Cy1 is generated between the second neighboring conductor 29y and the output side electrode 19 of the detection probe 13. The voltage Vy of the second neighboring conductor 29y generates a current Iy due to this capacitance Cy1. The current Iy is the current of the voltage noise component from the second neighboring conductor 29y.

Therefore, in the core wire of the shielded wire 25, in addition to the current I1 from the conductor 12 to be measured, the current Ix from the first neighboring conductor 29x and the current Iy from the second neighboring conductor 29y are mixed in the current Im (= I1). + Ix + Iy) will flow, and the current Im is input to the voltage detection unit 21m of the current input calculation unit 30. That is, the current Im includes the current I1 of the voltage component to be measured of the conductor 12 to be measured, the current Ix of the voltage noise component due to the first neighboring conductor 29x existing in the vicinity of the conductor 12 to be measured, and the second neighboring conductor 29y. The current Iy of the voltage noise component is included. This current Im is input to the negative terminal of the operational amplifier 22 of the voltage detection unit 21m of the current input calculation unit 30 through the core wire of the shield wire 25, and the output voltage Vo1 of the voltage detection unit 21m becomes Vo1 = −Im · Z. .. As a result, the voltage detection unit 21m of the current input calculation unit 30 obtains a detection voltage Vo1 proportional to the current Im (= I1 + Ix + Iy). The detection voltage Vo1 of the measurement target conductor 12 includes a measurement target voltage component for the current I1 from the measurement target conductor 12 and a voltage noise component for the current (Ix + Iy) from the neighboring conductor 29.

Next, since the voltage V1 of the measurement target conductor 12 is applied to the voltage noise batch detection unit 33, a current Ixy is generated through the capacitance Cxy between the voltage noise batch detection unit 33 and the measurement target conductor 12. The current Ixy is the current of the voltage component to be measured from the conductor 12 to be measured. Further, since the voltage Vx of the first neighboring conductor 29x is applied to the voltage noise batch detecting unit 33, the current Ix1 passes through the capacitance Cx2 between the voltage noise batch detecting unit 33 and the first neighboring conductor 29x. Occurs. The current Ix1 is the current of the voltage noise component from the first neighboring conductor 29x. Similarly, since the voltage Vy of the second neighboring conductor 29y is applied to the voltage noise batch detecting unit 33, the current Iy1 is passed through the capacitance Cy2 between the voltage noise batch detecting unit 33 and the second neighboring conductor 29y. Occurs. The current Iy1 is the current of the voltage noise component from the second neighboring conductor 29y.

Therefore, a current Ik (= Ixy + Ix1 + Iy1) flows through the shield portion of the shield wire 25 and is input to the voltage detection unit 21k of the current input calculation unit 30. That is, the current Ik includes the current Ix1 of the voltage noise component due to the first neighboring conductor 29x, the current Iy1 of the voltage noise component due to the second neighboring conductor 29y, and the current Ixy of the voltage component to be measured from the measurement target conductor 12. ing. This current Ik is input to the negative terminal of the operational amplifier 22k of the voltage detection unit 21k of the current input calculation unit 30 through the shield unit of the shield wire 25, and the output voltage Vo2 of the voltage detection unit 21 is Vo2 = -Ik · Z. Become. As a result, the voltage detection unit 21k of the current input calculation unit 30 obtains a detection voltage Vo2 proportional to the current Ik (= Ixy + Ix1 + Iy1). The detected voltage Vo2 of the conductor 12 to be measured contains a mixture of a voltage noise component corresponding to the current (Ixy) from the conductor 12 to be measured and a voltage noise component corresponding to the current (Ix1 + Iy1) from the neighboring conductor 29.

The detection voltage Vo1 of the voltage detection unit 21 of the current input calculation unit 30 and the detection voltage Vo2 of the voltage detection unit 21k of the current input calculation unit 30 are input to the correction voltage calculation unit 31. In the correction voltage calculation unit 31, the voltage noise component for the current (Ix + Iy) from the detection voltage Vo1 of the conductor 12 to be measured and the current (Ix + Iy) from the neighboring conductor 29, and the neighboring conductor 29 (first neighboring conductor 29x, second neighboring conductor 29y) The measured voltage of the measurement target conductor 12 obtained by removing the voltage noise component for the current (Ix1 + Iy1) from the neighboring conductor 29 from the detected voltage Vo2 is output as the output voltage Vout. That is, the correction voltage calculation unit 31 obtains the measurement voltage value of the measurement target voltage V1 by the calculation formula shown in (4) below and outputs it as the output voltage Vout.

Vout = K11 × (Vo1- (K12 × Vo2))… (4)
In the equation (4), K11 is a coefficient for taking a correspondence between the output voltage Vout and the voltage (measurement target voltage) V1 of the measurement target conductor 12 so that the correspondence becomes 1V at 100 Vrms. K12 is a coefficient such that the voltage noise component contained in V02 becomes the same level as the voltage noise component contained in V01. As a result, the voltage noise component due to the neighboring voltages Vx and Vy can be removed, and the value of the measurement target voltage V1 can be obtained with high accuracy.

FIG. 6 is an equivalent circuit of the isolated voltage detection device shown in FIG. Since the voltage V1 of the conductor 12 to be measured is applied to the output side electrode 19 of the detection probe 13 through the capacitance Cm, a current I1 is generated. The current I1 is the current of the voltage component to be measured. Further, since the voltages Vx and Vy of the first neighboring conductor 29x and the second neighboring conductor 29y are applied to the output side electrode 19 of the detection probe 13 through the capacitances Cx1 and Cy1, currents Ix and Iy are generated. The current Ix is the current of the voltage noise component due to the first neighboring conductor 29x, and the current Iy is the current of the voltage noise component due to the second neighboring conductor 29y. Therefore, a current Im (= I1 + Ix + Iy) flows through the core wire of the shielded wire 25. The current Im includes the current I1 (current of the voltage component to be measured) due to the voltage V1 of the conductor to be measured, the voltage Vx of the first neighboring conductor 29x and the second neighboring conductor 29y, and the currents Ix and Iy (current of the voltage noise component) due to Vy. ) And the components are mixed.

On the other hand, since the voltage V1 of the conductor 12 to be measured is applied to the voltage noise batch detection unit 33 through the capacitance Cxy, a current Ixy is generated. The current Ixy is the current of the voltage component to be measured from the conductor 12 to be measured. Further, since the voltages Vx and Vy of the first neighboring conductor 29x and the second neighboring conductor 29y are applied to the voltage noise batch detection unit 33 through the capacitances Cx2 and Cy2, currents Ix1 and Iy1 are generated. The current Ix1 is a voltage noise component from the first neighboring conductor 29x, and the current Iy1 is a current of the voltage noise component from the second neighboring conductor 29y. Therefore, a current Ik (= Ixy + Ix1 + Iy1) flows through the shield portion of the shield wire 25. The current Ik includes a component (voltage noise) of the current Ixy (current of the voltage component to be measured) due to the voltage V1 of the conductor to be measured and the currents Ix1 and Iy1 due to the voltage Vx and Vy of the first neighboring conductor 29x and the second neighboring conductor 29y. The current of the components) is mixed.

Therefore, in the equation (4), the coefficient K12 so as to be at the same level as the voltage noise components of the neighboring voltages Vx and Vy included in the current Im flowing in the core wire of the shield wire 25 is set to the current Ik flowing in the shield portion of the shield wire 25. Multiply. As described above, the coefficient K11 is a coefficient for taking a correspondence between the output voltage Vout and the voltage (measurement target voltage) V1 of the measurement target conductor 12 so that the correspondence becomes 1V at 100 Vrms. As a result, the output voltage Vout corresponds only to the measurement target voltage V1.

Here, in FIG. 5, the shield portion of the shield wire 25 constituting the voltage noise batch detection unit 33 is not connected to the ground (GND), but the minus of the operational amplifier 22k of the voltage detection unit 21k of the current input calculation unit 30. Connected to the input terminal, the voltage detection unit 21k constitutes an I / V conversion circuit. Since the negative input terminal of the I / V conversion circuit has the same GND potential as the operational amplifier 22k, the electrical relationship of the shielded wire 25 seen from the output side electrode 19 is the shielded wire 25 (shielded portion is grounded) shown in FIG. It becomes the same as the shield wire 25).

Therefore, the current Im from the output side electrode 19 is set to the voltage detection unit 21m of the current input calculation unit 30 as the current Im regardless of the capacitance of the shield wire 25 or the double shield wire 32 or the change in capacitance due to routing. Entered. Further, as described above, since the voltage noise batch detection unit 33 has a circular structure, a plurality of voltage noise detection electrodes 27 are not required as in the first embodiment shown in FIG. Further, except for the voltage noise batch detection unit 33 of the shield wire 25, since it is covered with GND by the outer shield portion of the double shield wire 32, it is not affected by the external electric field of the portion where the double shield wire 32 is routed.

Further, in the above description, the detection probe 13 has a dielectric 20A and an output side electrode 19 arranged in contact with the outer surface of the insulating coating 26 of the electric wire 11 to be measured, which is shown in FIG. As described above, the conductor side electrode 18 may be provided on the measurement target electric wire 11 side of the dielectric 20A. As a result, the conductor side electrode 18 is arranged in contact with the outer surface of the insulating coating 26 of the electric wire 11 to be measured. The conductor-side electrode 18 is larger than the output-side electrode 19, and is formed so that the dielectric 20A is located between the conductor-side electrode 18 and the output-side electrode 19. By providing the conductor-side electrode 18, it is possible to reduce the influence of the wire diameter (diameter of the thickness of the insulating coating) of the wire 11 to be measured and the diameter of the conductor. Since the other configurations are the same as those of the insulated voltage measuring device shown in FIG. 5, the same elements are designated by the same reference numerals and duplicate description is omitted. Thus, according to the second embodiment, the detection probe The shield wire 25 for extracting the current from the output side electrode 19 of 13 is further shielded as a double shield wire 32, and the end of the shield portion of the shield wire 25 exposed from the outer shield of the double shield wire 32 to the detection probe 13 side. Is the voltage noise batch detection unit 33, so that the output side electrode 19 of the detection probe 13 remains the same as the structure of the output side electrode 19 of FIG. 9, not only when there is no neighboring conductor 29, but also when a plurality of electric wires or large wires are used. It is possible to realize an insulated voltage measuring device that can be used even in the field where there is a small diameter electric wire. Further, even when the positional relationship between the measurement target electric wire 11 and the proximity electric wire 29 is not constant, it is possible to realize an insulated voltage measuring device that can be used.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

11 ... Measurement target electric current, 12 ... Measurement target conductor, 13 ... Detection probe, 14 ... First electrode, 15 ... Second electrode, 16 ... Voltage detection circuit, 17 ... AC power supply, 18 ... Conductor side electrode, 19 ... Output side Electrodes, 20, 20A ... Dielectric, 21 ... Voltage detector, 22 ... Operate, 23 ... Detection probe holding part, 24 ... Recess, 25 ... Shielded wire, 26 ... Insulation coating, 27 ... Voltage noise detection electrode, 28 ... Neighborhood Electric wire, 29 ... Proximity conductor, 30 ... Current input calculation unit, 31 ... Correction voltage calculation unit, 32 ... Double shielded wire, 33 ... Voltage noise batch detection unit

Claims (2)

A detection probe that detects the voltage component to be measured on the conductor of the voltage measurement object by current, including the voltage noise component from the conductor of the neighboring electric wire located on the outer surface of the voltage measurement object and existing in the vicinity of the voltage measurement object. ,
A voltage noise detection electrode arranged in the vicinity of the conductor of the neighboring electric wire and detecting the voltage noise component including the measurement target voltage component as a current,
A current input calculation unit that inputs the current detected by the detection probe through the shield wire and converts it into a voltage, and inputs the current detected by the voltage noise detection electrode through the shield wire and converts it into a voltage.
A correction voltage that removes the voltage noise component from the detection voltage in which the conductor measurement target voltage component and the voltage noise component converted into voltage by the current input calculation unit are mixed to obtain the measurement voltage of the conductor of the voltage measurement target. An isolated voltage measuring device characterized by having a calculation unit. A detection probe that detects the voltage component to be measured on the conductor of the voltage measurement object by current, including the voltage noise component from the conductor of the neighboring electric wire located on the outer surface of the voltage measurement object and existing in the vicinity of the voltage measurement object. ,
The shield wire for extracting the current detected by the detection probe is further shielded as a double shield wire, and the end portion of the shield portion of the shield wire is exposed from the outer shield portion of the double shield wire to the detection probe side. A voltage noise batch detection unit that detects the voltage noise component including the measurement target voltage component as a current, and
The shielded portion of the shielded wire that can input the current detected by the detection probe from the core wire of the shielded wire to the current-voltage conversion circuit and convert it into a voltage, and can regard the current detected by the voltage noise batch detector as a grounded state. A current input calculation unit that inputs to the current-voltage conversion circuit via the voltage noise unit and converts the current detected by the voltage noise batch detection unit into a voltage.
A correction voltage that removes the voltage noise component from the detection voltage in which the conductor measurement target voltage component and the voltage noise component converted into voltage by the current input calculation unit are mixed to obtain the measurement voltage of the conductor of the voltage measurement target. An isolated voltage measuring device characterized by having a calculation unit.

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