JPH08160082A - Method and device for detecting insulation deterioration - Google Patents

Method and device for detecting insulation deterioration

Info

Publication number
JPH08160082A
JPH08160082A JP32967594A JP32967594A JPH08160082A JP H08160082 A JPH08160082 A JP H08160082A JP 32967594 A JP32967594 A JP 32967594A JP 32967594 A JP32967594 A JP 32967594A JP H08160082 A JPH08160082 A JP H08160082A
Authority
JP
Japan
Prior art keywords
resonance circuit
lc resonance
insulation
object
insulation resistance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP32967594A
Other languages
Japanese (ja)
Inventor
Makoto Kawakami
Shigeru Yamaguchi
Masato Yasuoka
正登 安岡
茂 山口
川上  誠
Original Assignee
Sumitomo Special Metals Co Ltd
住友特殊金属株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Special Metals Co Ltd, 住友特殊金属株式会社 filed Critical Sumitomo Special Metals Co Ltd
Priority to JP32967594A priority Critical patent/JPH08160082A/en
Publication of JPH08160082A publication Critical patent/JPH08160082A/en
Granted legal-status Critical Current

Links

Abstract

PURPOSE: To provide an insulation deterioration detecting method by which the degree of deterioration of the insulation resistances of various kinds of equipment used in electric automobiles, fuel battery power generation systems, etc., without a direct grounding. CONSTITUTION: A capacitor 4 having a capacitance (Cc) which is sufficiently larger than the presumed maximum capacitance (Cs) between an object 1 to be measured, such as the electric automobile, etc., and earth 2 is connected in series between an LC resonance circuit 3 connected to an AC power source 5 which is provided as an energy source for maintaining oscillation and the object 1 so as to make the influence of the output caused by the capacitance between the object 1 and earth (ground) 2 substantially zero. In addition, since an electric circuit (not shown in the figure) can change (fo→fs) the resonance frequency of the power source 5 in accordance with the capacitance (Cs) between the object 1 and ground 2 is provided to the power source, the insulation resistance (Rs) between the object 1 and earth 2 can be found by measuring the voltage (Vm) of the circuit 3 when the insulation resistance (Rs) is limited.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting insulation deterioration in an electric vehicle, a fuel cell power generation system, or the like, in which an LC resonance circuit capable of maintaining oscillation is connected to an object to be measured through a capacitor, and an insulation resistance The present invention relates to an insulation deterioration detecting method and device capable of determining deterioration or accurately measuring insulation resistance without grounding deterioration.

[0002]

2. Description of the Related Art Recently, devices using direct current have been used in a wide range of fields. During maintenance and management for smooth operation of these various devices, the insulation resistance of each device is measured, It is necessary to monitor the condition of insulation deterioration.

Conventionally, as a measuring instrument for measuring the insulation resistance of equipment or the insulation resistance between an electric line and ground,
Evershed & Vignoles in the UK
An insulation resistance meter called a company-made megger (trade name, Megger) is known. The insulation resistance tester includes a magnet M,
It consists of a ratio meter composed of a current coil C and a voltage coil P, and a hand-wound DC generator G. When measuring the insulation resistance of the device, the device is connected between measurement terminals E-L to connect the current coil C to the device. When the voltage coil P is connected in parallel with the power source G in series with the unknown resistor X, a clockwise torque is generated in the current coil and the pointer is swung in a predetermined direction. At this time, torque is also generated in the voltage coil and the voltage is generated. The pointer stops when the coil and current coil are balanced, and the insulation resistance can be measured.

When the insulation resistance between the electric line and the ground is measured by an insulation resistance meter, the core wire of the electric wire is connected to the L terminal and the E terminal is connected to the ground, which is measured by the above-mentioned operation. By connecting the protective terminal GR to the insulator of the electric wire, the measurement error due to the leakage current flowing on the surface of the insulator is reduced.

[0005]

Although it is possible to measure the insulation resistance of various devices with a conventionally known insulation resistance meter such as a Megger, these insulation resistance meters are objects to be measured. Since it is necessary to electrically connect various devices to the ground directly, it cannot be used in applications such as in electric vehicles, for example, where the condition of insulation deterioration is constantly monitored during operation. That is, it is impossible for the conventional insulation resistance meter to measure the degree of insulation deterioration of the device without grounding.

In view of the above-mentioned circumstances, the present invention has as its main object to provide an insulation deterioration detecting method and its device capable of measuring the degree of deterioration of insulation resistance of various devices without DC grounding, and in particular to DC The purpose of the present invention is to realize maintenance and management for smoothly operating the equipment using a wide range of fields.

[0007]

As a result of various studies to achieve the above object, the present invention provides an object to be measured by effectively disposing an LC resonant circuit capable of maintaining oscillation by an external power supply. It was found that it is possible to measure the insulation resistance between the DUT and the earth (ground) with high accuracy by making the effect of the output due to the capacitance between the earth and the earth (ground) substantially zero. , Completed.

That is, according to the present invention, an LC resonance circuit capable of maintaining oscillation by an external power supply is connected to a device under test through a capacitor connected in series with the LC resonance circuit, and the device under test is not grounded. The insulation deterioration detecting method is characterized in that the deterioration of the insulation resistance or the resistance value is judged or measured by comparing with the voltage of the LC resonance circuit or further with the power supply voltage. In the above configuration,
We also propose an insulation deterioration detection method in which the L portion of the LC resonance circuit is composed of a synthetic inductance made of a semiconductor.

Further, according to the present invention, an LC resonance circuit capable of maintaining oscillation by an external power supply whose drive frequency is variable, a capacitor connected in series between the LC resonance circuit and an object to be measured, an external power supply and the LC resonance circuit are provided. The insulation deterioration detecting device according to claim 1, further comprising means for measuring or comparing the voltage. Further, in the above configuration, L
This invention also proposes an insulation deterioration detecting device characterized in that the portion L constituting the C resonance circuit is constituted by a synthetic inductance made of a semiconductor. Further, in the above configuration, an insulation deterioration detecting device in which a correction circuit having an operational amplifier is connected to the combined inductance is also proposed.

[0010]

The operation of the present invention will be described with reference to the electric circuit conceptual diagram shown in FIG. In FIG. 1, reference numeral 1 is an object to be measured such as an electric vehicle, and 2 is an earth (ground) which is located at a predetermined distance from the object to be measured 1. Reference numeral 3 is an LC resonance circuit, which comprises the DUT 1 and the capacitor (Cc) 4 described above.
Are connected in series via. Further, the LC resonance circuit 3 is electrically coupled to an AC power supply 5 serving as an energy supply source in order to maintain oscillation. 6 (Rc) in the figure is
The configuration in the case where the coupling coefficient of the LC resonance circuit 3 is indicated by a resistance is shown.

In this configuration, the DUT 1 and the ground 2 are
A capacitance (Cs) is generated between them, but the capacitance (Cc) of the capacitor 4 arranged between the LC resonance circuit 3 and the DUT 1 in advance is larger than the capacitance between the ground (Cs). ) Is set sufficiently large (Cc> Cs). Here, when the insulation between the DUT 1 and the earth 2 is completely ensured, the insulation resistance (Rs) between the DUT 1 and the earth 2 becomes infinite (Rs = ∞), and the AC power supply 5 Voltage (Vo) and L
It becomes equal to the voltage (Vm) of the C resonance circuit 3 (Vm = V
o).

For example, when the distance between the device under test 1 and the earth 2 changes and the capacitance between the ground (Cs) changes, the resonance frequency also changes (fo → fs). Therefore, the operation of the LC resonance circuit 3 is performed. In order to maintain the above, it is necessary to change the frequency of the AC power supply 5 which is the energy supply source in accordance with the fluctuation of the ground capacitance (Cs). By adjusting the frequency of the AC power supply 5, , The voltage of the AC power supply 5 (V
The relationship between (o) and the voltage (Vm) of the LC resonance circuit 3 can be maintained at (Vm = Vo) as in the above case. The frequency adjustment of the AC power supply 5 is easily realized by arranging an electronic circuit or the like (not shown) configured to automatically adjust the oscillation frequency so that the voltage (Vm) of the LC resonance circuit 3 is maximized. it can.

Under these conditions, the insulation between the device under test 1 and the ground 2 deteriorates, and the device under test 1 and the ground 2 are degraded.
When the insulation resistance (Rs) between them has a finite value, the relationship between the voltage (Vo) of the AC power supply 5 and the voltage (Vm) of the LC resonance circuit 3 is Vm = Vo. [Rs / (Rs + Rc)] Become. However, since the voltage (Vo) of the AC power supply 5 and the resistance (Rc) indicating the coupling coefficient of the LC resonance circuit 3 are known values, the object to be measured is measured by measuring the voltage (Vm) of the LC resonance circuit 3. The insulation resistance (Rs) between 1 and ground 2 can be obtained. That is, by measuring the voltage (Vm) of the LC resonant circuit 3, it is possible to constantly monitor the degree of insulation deterioration of the DUT without DC grounding between the DUT 1 and the ground 2. is there. Further, by providing an electric circuit for comparing the voltage (Vm) of the LC resonance circuit 3 and the voltage (Vo) of the AC power supply 5, similarly, the degree of insulation deterioration of the object to be measured can be constantly monitored, and the detection device It becomes possible to improve the temperature coefficient.

In the insulation deterioration detecting apparatus of the present invention, the LC resonance circuit, which maintains oscillation by being electrically connected from the outside, is connected to the object to be measured via the capacitor connected in series with the LC resonance circuit. The configuration is not limited to the configuration shown in FIG.
In particular, the form of L (inductance) that constitutes the LC resonance circuit in consideration of the required measurement range of the insulation resistance, the size of the device itself, the productivity, and the like It is desirable to appropriately select the arrangement form of the energy supply source (AC power supply) that is electrically coupled.

In the configuration of FIG. 1, the resistor (Rc) indicating the coupling coefficient of the LC resonant circuit 3 is arranged between the LC resonant circuit and the energy supply source (AC power source), but, for example, The same operation can be realized by arranging a capacitor other than Rc in series between the LC resonance circuit and the energy supply source (AC power supply). Further, a similar effect can be realized by providing a link coil in the inductor of the resonance circuit and supplying an oscillating current to the inductor, and these configurations can be appropriately selected according to various conditions required.

As for L (inductance) that constitutes the LC resonance circuit, if the resonance frequency is high, noise from the circuit to be measured and changes in the capacitance between the ground are greatly affected, so that the resonance frequency is several Hz or less. Is desirable. Therefore, it is necessary to obtain a large inductance,
The efficiency is poor only with the air-core coil, and a configuration in which a ring-shaped soft magnetic material or the like is arranged is adopted. In another embodiment of the present invention shown in FIG. 2, L constituting an LC resonance circuit is formed.
A ring-shaped soft magnetic material 7 is used for (inductance), and an exciting coil 8 penetrating the soft magnetic material 7 is connected to an AC power source 5 which is an energy supply source for maintaining oscillation of the LC resonance circuit 3. It consists of a composition. Also in this configuration, as in the case of FIG. 1, the frequency of the AC power supply 5 is adjusted by following the fluctuation of the ground capacitance (Cs) between the DUT 1 and the ground 2, and the voltage of the LC resonance circuit 3 is adjusted. By measuring (Vm), the insulation resistance (Rs) between the DUT 1 and the ground 2 can be obtained.

Further examination of the configuration shown in FIG.
The magnetic characteristics of the soft magnetic material 7 depend on the voltage (V
It can be seen that m) is greatly affected. That is, L
Since the voltage (Vm) of the C resonance circuit 3 is inversely proportional to the product of the hysteresis loss of the soft magnetic material 7 and the LC resonance frequency (= frequency of the AC power supply 5), the soft magnetic material 7 has a small hysteresis loss, That is, it becomes possible to measure a large insulation resistance with high sensitivity by using a material having a high maximum relative magnetic permeability (μm).

It is also possible to increase the L (inductance) by increasing the number of coils wound around the soft magnetic material 7 in order to lower the LC resonance frequency, but in order to measure a large insulation resistance, it is possible to increase the L (inductance). Since the number of coil turns also becomes very large, it is desirable to select the number of coil turns and the material of the soft magnetic material 7 according to the measurement range of the insulation resistance. For example, in the configuration of FIG. 2, when silicon steel (Fe-Si alloy) is used as the ring-shaped soft magnetic material 7, the maximum relative magnetic permeability (μm) is 1,000 to
Since it is about 5,000, the number of coil turns is 3,000.
When it is set to about 0 turns (T), a relatively small insulation resistance up to several 100Ω can be measured.

If permalloy (Fe-Ni type alloy) is used as the ring-shaped soft magnetic material 7, silicon steel (F
It is possible to measure much higher insulation resistance than when using an e-Si alloy), and PC permalloy (78Ni-Fe-Mo-Cu) containing a predetermined amount of Mo, Cu or the like.
Etc.), the maximum relative magnetic permeability (μm) is 100,000 to 7
The number of coil turns is 3000 because it is about 0,000.
Even if it is about turn (T), 100 kΩ or more to 500 k
A large insulation resistance of Ω or more can be measured.

Examples of the ring-shaped soft magnetic material 7 include PD permalloy and PB in addition to the above-mentioned silicon steel and PC permalloy.
Permalloy, Sendust (Fe-Al-Si based alloy),
By adopting a known material such as soft ferrite, the target insulation resistance can be efficiently measured.

In the structure shown in FIG. 2, the ring-shaped soft magnetic material 7 is arranged in the L (inductance) portion of the LC resonance circuit. However, the number of coil turns on the ring-shaped soft magnetic material 7 is large. As the number of turns increases, the productivity deteriorates, and the number of coil turns is limited. Therefore, the present inventor studied to configure this portion with a synthetic inductance made of a semiconductor.

The configuration shown in FIG. 3 is an embodiment of the insulation deterioration detecting device according to the present invention, characterized in that the portion L constituting the LC resonance circuit is constituted by a synthetic inductance made of a semiconductor. With this configuration, since the ring-shaped soft magnetic material and the winding on the ring-shaped soft magnetic material are not required, it is possible to obtain with high productivity an insulation deterioration detecting device having the same characteristics as those of the configuration of FIG. it can.

In FIG. 3, the synthetic inductance 9 made of semiconductor is composed of operational amplifiers (10a, 10b) and CR (C).
1 , R 1 , R 2 ) are synthesized. In this configuration, a wide range of insulation resistance can be measured by appropriately selecting the values of Cr, C 1 and R 1 . For example, a large insulation resistance of 100 kΩ or more and 500 kΩ or more can be measured by setting the combined inductance 9 to 100 H or more and 1 kH or more.

The structure of FIG. 4 shows an insulation deterioration detecting device which is a modification of the structure of FIG. 3, and further includes an operational amplifier 12 and a predetermined resistor (R 3 ) 13 in addition to the combined inductance 9.
The output of the resonance circuit is made into a rectangular wave with a constant wave height by connecting the correction circuit 11 consisting of, and further positive feedback is applied, and the fluctuation of the ground-to-ground electrostatic capacitance (Cs) and the position near the object to be measured are arranged. Since it is possible to maintain a stable oscillation amplitude while automatically following changes in resonance frequency due to changes in capacitance that occur between the housings, it is possible to reliably cancel the influence of the capacitance described above. It is possible to obtain the output only by the intended insulation resistance. Although only the resonance circuit portion and the correction circuit 11 portion are shown in FIG. 4, the other configurations are the same as those in FIG.

[0025]

【Example】

Example 1 In the insulation deterioration detecting apparatus of the present invention shown in FIG. 2, the ring-shaped soft magnetic material 7 has a maximum magnetic permeability (μm) of 2,0.
00 steel and maximum permeability (μm) of 250,0
Insulation resistance (R per 00 PC Permalloy)
FIG. 5 shows the relationship between s) and the voltage (Vm) of the LC resonance circuit 3. However, each of the ring-shaped soft magnetic materials 7 made of silicon steel and PC permalloy had a plate thickness of 0.5 mm, an outer diameter of 45 mm, an inner diameter of 33 mm, and a number of 33 sheets, and a wire diameter of 0.
A 15 mm enamel wire was wound 3,000 turns (T). In addition, the capacitor (C
r) was 1 μF, the capacitor (Cc) arranged between the LC resonance circuit 3 and the object to be measured was 0.1 μF, and the resonance frequency was set to 5 Hz for measurement. The equivalent resistance (R loss ) indicating the loss of the LC resonance circuit 3 is 1 kΩ for silicon steel and 500 kΩ for PC permalloy.
Met.

As is apparent from FIG. 5, when PC permalloy is used, the conductance (1 / Rs) is 1
In the range of μS to 10 μS, that is, when the insulation resistance (Rs) is 1,000 kΩ to 100 kΩ, a large displacement appears in the output voltage, and when silicon steel is used, the conductance (1 / Rs) is 500 μS to 5, 000
Since a large displacement appears in the output voltage in the μS range, that is, in the insulation resistance (Rs) of 2 kΩ to 0.2 kΩ, it can be seen that highly sensitive measurement of the insulation resistance (Rs) can be realized in each of the above ranges.

Embodiment 2 In the insulation deterioration detecting apparatus of the present invention shown in FIG. 3, a capacitor C 1 = 1 μF constituting a combined inductance,
Resistor R 1 = 20 kΩ, R 2 = 20 kΩ (combined inductance L = 400 H), and capacitor Cr =
4.4 μF, the capacitor Cc between the resonance circuit 3 and the object to be measured is 1 μF, and the resonance frequency is 3.4 Hz.
FIG. 6 shows the relationship between the insulation resistance (Rs) and the voltage (Vm) of the resonance circuit 3 when set to.

As is apparent from FIG. 6, a large displacement appears in the output voltage when the conductance (1 / Rs) is in the range of 1 μS to 10 μS, that is, when the insulation resistance (Rs) is in the range of 1 MΩ to 100 kΩ.
It can be seen that highly sensitive measurement of insulation resistance (Rs) can be realized.

[0029]

According to the present invention, between an LC resonance circuit to which an AC power source serving as an energy supply source is connected in order to maintain oscillation and an object to be measured such as an electric vehicle, and an object to be measured and a ground 2 which are assumed in advance. Capacitor (Cc), which is sufficiently larger than the maximum capacitance (Cs), is placed in series to substantially eliminate the influence of the output due to the capacitance between the DUT and the earth (ground), and For the AC power supply, the ground capacitance (C
If an insulation circuit (Rs) between the object to be measured and the ground has a finite value by disposing an electronic circuit etc. that can change the resonance frequency (fo → fs) with the change of (s), the voltage (Vo) of the AC power supply And the voltage (Vm) of the LC resonance circuit is V
Since m = Vo · [Rs / (Rs + Rc)],
By measuring the voltage (Vm) of the LC resonance circuit, the insulation resistance (Rs) between the object to be measured and the ground can be obtained, and the insulation deterioration of the object to be measured can be achieved without grounding the object to be measured and the ground. The degree can be constantly monitored.

As is apparent from the above-described embodiments, the insulation deterioration detecting device of the present invention makes it possible to measure the insulation resistance of the object to be measured without DC grounding. It is possible to constantly monitor the status of insulation deterioration even during operation, further improve the accuracy of maintenance management, and realize maintenance management for operating DC equipment smoothly in a wide range of fields. It becomes possible.

[Brief description of drawings]

FIG. 1 is a conceptual explanatory diagram of an electric circuit for explaining the operation principle of the insulation deterioration detecting device of the present invention.

FIG. 2 is a conceptual explanatory diagram of an electric circuit showing an embodiment of the insulation deterioration detecting device of the present invention.

FIG. 3 is a conceptual explanatory diagram of an electric circuit showing an embodiment of the insulation deterioration detecting device of the present invention.

FIG. 4 is a conceptual explanatory diagram of an electric circuit showing an embodiment of the insulation deterioration detecting device of the present invention.

5 is a graph showing the relationship between the insulation resistance (Rs) and the voltage (Vm) of the resonance circuit 3 when the insulation deterioration detecting device shown in FIG. 2 is used.

6 is a graph showing the relationship between the insulation resistance (Rs) and the voltage (Vm) of the resonance circuit 3 when the insulation deterioration detecting device shown in FIG. 3 is used.

[Explanation of symbols]

1 DUT 2 Ground 3 LC resonance circuit 4 Capacitor 5 AC power supply 6, 13, R 1 , R 2 , R 3 , Rc Resistor 7 Soft magnetic material 8 Excitation coil 9 Inductance 10a, 10b, 12 Opamp 11 Correction circuit C 1 , Cc, Cs, Cr Capacitor capacitance Vo, Vm Voltage L Inductance Rs Insulation resistance R 1 , R 2 , R 3 , Rc Resistance value

Claims (5)

[Claims]
1. An LC capable of maintaining oscillation by an external power supply.
The resonance circuit is connected to the DUT through a capacitor connected in series with the LC resonance circuit, and the insulation resistance is degraded or the resistance value is changed to the voltage of the LC resonance circuit without grounding the DUT in a DC manner. Alternatively, an insulation deterioration detecting method is characterized by further judging or measuring by comparing with the power supply voltage.
2. The insulation deterioration detecting method according to claim 1, wherein the L portion of the LC resonance circuit is formed of a synthetic inductance made of a semiconductor.
3. An LC resonance circuit capable of maintaining oscillation by an external power supply whose drive frequency is variable, a capacitor connected in series between the LC resonance circuit and an object to be measured, and a voltage applied to the external power supply and the LC resonance circuit. The insulation deterioration detecting device according to claim 1, further comprising a comparing means.
4. The insulation deterioration detecting device according to claim 3, wherein the L portion constituting the LC resonance circuit is constituted by a synthetic inductance made of a semiconductor.
5. The insulation deterioration detecting device according to claim 3, wherein a correction circuit having an operational amplifier is connected to the combined inductance.
JP32967594A 1994-12-02 1994-12-02 Method and device for detecting insulation deterioration Granted JPH08160082A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP32967594A JPH08160082A (en) 1994-12-02 1994-12-02 Method and device for detecting insulation deterioration

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP32967594A JPH08160082A (en) 1994-12-02 1994-12-02 Method and device for detecting insulation deterioration

Publications (1)

Publication Number Publication Date
JPH08160082A true JPH08160082A (en) 1996-06-21

Family

ID=18224018

Family Applications (1)

Application Number Title Priority Date Filing Date
JP32967594A Granted JPH08160082A (en) 1994-12-02 1994-12-02 Method and device for detecting insulation deterioration

Country Status (1)

Country Link
JP (1) JPH08160082A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011062907A2 (en) * 2009-11-19 2011-05-26 Valence Technology, Inc. Battery insulation resistance measurement methods, insulation resistance, measurement methods, insulation resistance determination apparatuses, and aritcles of manufacture
JP2011154028A (en) * 2010-01-26 2011-08-11 Maxim Integrated Products Inc Isolation monitoring system and method utilizing variable emulated inductance
WO2012036498A2 (en) * 2010-09-17 2012-03-22 Sk Innovation Co.,Ltd. Insulation resistance measurement circuit having self-test function without generating leakage current
CN104166048A (en) * 2014-07-25 2014-11-26 广西电网公司电力科学研究院 Power frequency interference resistant insulation resistor testing apparatus and testing method based on resonance network
WO2017009891A1 (en) * 2015-07-10 2017-01-19 株式会社東芝 Internal-resistance deriving device, battery device, and internal-resistance-value deriving method

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011062907A2 (en) * 2009-11-19 2011-05-26 Valence Technology, Inc. Battery insulation resistance measurement methods, insulation resistance, measurement methods, insulation resistance determination apparatuses, and aritcles of manufacture
WO2011062907A3 (en) * 2009-11-19 2011-11-24 Valence Technology, Inc. Battery insulation resistance measurement methods, insulation resistance, measurement methods, insulation resistance determination apparatuses, and aritcles of manufacture
US9581652B2 (en) 2009-11-19 2017-02-28 Valence Technology, Inc. Battery insulation resistance measurement methods, insulation resistance measurement methods, insulation resistance determination apparatuses, and articles of manufacture
CN104977468B (en) * 2009-11-19 2018-06-01 威伦斯技术公司 Battery insulation resistance measurement method, insulation measurement method, insulation resistance determining device
CN104977468A (en) * 2009-11-19 2015-10-14 威伦斯技术公司 Battery Insulation Resistance Measurement Methods, Insulation Resistance Measurement Methods, Insulation Resistance Determination Apparatuses, And Aritcles Of Manufacture
JP2011154028A (en) * 2010-01-26 2011-08-11 Maxim Integrated Products Inc Isolation monitoring system and method utilizing variable emulated inductance
WO2012036498A2 (en) * 2010-09-17 2012-03-22 Sk Innovation Co.,Ltd. Insulation resistance measurement circuit having self-test function without generating leakage current
US9069024B2 (en) 2010-09-17 2015-06-30 Sk Innovation Co., Ltd. Insulation resistance measurement circuit having self-test function without generating leakage current
WO2012036498A3 (en) * 2010-09-17 2012-05-10 Sk Innovation Co.,Ltd. Insulation resistance measurement circuit having self-test function without generating leakage current
CN103250061A (en) * 2010-09-17 2013-08-14 Sk新技术株式会社 Insulation resistance measurement circuit having self-est function without generating leakage current
CN104166048A (en) * 2014-07-25 2014-11-26 广西电网公司电力科学研究院 Power frequency interference resistant insulation resistor testing apparatus and testing method based on resonance network
WO2017009891A1 (en) * 2015-07-10 2017-01-19 株式会社東芝 Internal-resistance deriving device, battery device, and internal-resistance-value deriving method

Similar Documents

Publication Publication Date Title
US8901919B2 (en) Compact, two stage, zero flux electronically compensated current or voltage transducer employing dual magnetic cores having substantially dissimilar magnetic characteristics
Ripka Electric current sensors: a review
US9291649B2 (en) On the enhancements of planar based RF sensor technology
US6411078B1 (en) Current sensor apparatus
US6698299B2 (en) Magnetoelastic torque sensor
CN100485407C (en) Magnetic field sensor and electrical current sensor thereof
Ramboz Machinable Rogowski coil, design, and calibration
JP5064712B2 (en) Current measuring device
US5414400A (en) Rogowski coil
US2542057A (en) Method and apparatus for measuring the conductivity of an electrolyte
EP0792465B1 (en) A device for sensing of electric discharges in a test object
DE69915816T2 (en) Current measuring device
US5659251A (en) Electromagnetic inductive probe
EP2293308B1 (en) Electric measuring device comprising a nanocrystalline toroidal core
US5017859A (en) Integral capacitive divider bus bar voltage measuring apparatus and combined current sensor
US7274186B2 (en) Temperature compensated and self-calibrated current sensor
EP0544646B1 (en) Apparatus for assessing insulation conditions
EP0587491B1 (en) Measuring appliance using Rogowski coil
US6715198B2 (en) Method of manufacturing a magnetic sensor
US20080079418A1 (en) High-precision rogowski current transformer
US5338332A (en) Current sensor using current transformer with sintered primary
Moore et al. The current comparator
US5066904A (en) Coaxial current sensors
CA2138822C (en) Dc current sensor
KR20050099611A (en) Method for measuring power in a transformer coupled plasma source