Non-contact electrical parameter measurement system

Abstract

To provide measurement of AC electrical parameters in an insulated wire without requiring a galvanic connection between the insulated wire and a test probe.SOLUTION: A measurement system may include a housing that includes both a non-contact voltage sensor and a non-contact current sensor. The measurement system obtains measurements from the voltage sensor and the current sensor during a measurement time interval, and processes the measurements to determine AC electrical parameters of the insulated wire. The AC electrical parameters may be presented to an operator via a visual indicator device (e.g., display, lights). The AC electrical parameters may additionally or alternatively be communicated to an external device via a wired and / or wireless communications interface. The measurement system may include an alignment feedback sensor that provides a user with feedback regarding the mechanical alignment of the insulated wire relative to the voltage sensor and the current sensor.SELECTED DRAWING: Figure 28

Claims

[Claim 1] A non-contact measurement system for measuring voltage or current within an insulated wire without directly making electrical contact with the insulated wire, A housing including a front end comprising a first end portion, a second end portion, and a receiving portion between the first and second end portions, and a gripping portion that is held by the operator of the non-contact measuring system during measurement, The housing comprises at least one processor, A voltage sensor that is physically coupled to the housing and selectively positionable in close proximity to the insulated wire, and which operates to generate a voltage sensor signal indicating the voltage within the insulated wire by capacitive coupling to the insulated wire without directly making electrical contact with the insulated wire, An internal grounding guard, which at least partially surrounds the voltage sensor and is directly electrically coupled to the internal electrical ground of the non-contact measuring system, is made of a conductive material and has dimensions such that it shields the voltage sensor from stray currents. A reference shielding body that surrounds at least a portion of the housing and does not make direct electrical contact with the internal earth guard, and is made of a conductive material that capacitively couples with the external earth, and is sized to reduce the current between the internal earth guard and the external earth. A common-mode reference voltage source electrically coupled between the internal earth guard and the reference shield, which generates an AC reference voltage having a reference frequency during operation, A first alignment feedback sensor for the first end portion and a second alignment feedback sensor for the second end portion, wherein each of the first and second alignment feedback sensors is operably coupled to the at least one processor, and when operating, each of the first and second alignment feedback sensors detects the voltage in the insulated wire when the insulated wire is positioned near the first and second alignment feedback sensors, and in response generates an alignment feedback sensor signal indicating the current alignment of the insulated wire with respect to the receiving portion, An indicator device operably coupled to at least one processor, wherein, during operation, the at least one processor receives the alignment feedback sensor signal and causes the indicator device to provide an alignment indicator to the operator of the non-contact measurement system based at least partially on the alignment feedback sensor signal, the alignment indicator indicating the degree of alignment of the insulated wire with respect to the receiving portion, The device includes a current sensor provided near the front end of the housing, which, during operation, senses the current in the insulated wire without directly making electrical contact with the insulated wire. During operation, the at least one processor, The voltage sensor signal acquired by the voltage sensor during the measurement time interval, which indicates the voltage in the insulated wire, is received from the voltage sensor. The current sensor signal acquired by the current sensor during the measurement time interval, which indicates the current in the insulated wire, is received from the current sensor. A non-contact measurement system that determines at least one alternating current (AC) electrical parameter based at least in part on the voltage sensor signal and the current sensor signal, and also on the human body capacitance, which is the operator's capacitance to ground when the operator grasps the gripping portion of the non-contact measurement system. [Claim 2] The non-contact measurement system according to claim 1, wherein the current sensor includes a magnetic field sensor. [Claim 3] The non-contact measurement system according to claim 1 or 2, wherein the voltage sensor, during operation, senses a voltage in the insulated wire having a frequency different from the reference frequency of the AC reference voltage generated by the common-mode reference voltage source of the non-contact measurement system, without directly making electrical contact with the insulated wire. [Claim 4] The non-contact measurement system according to any one of claims 1 to 3, wherein the at least one AC electrical parameter includes at least one of power, phase, frequency, harmonics, or energy. [Claim 5] The non-contact measurement system according to any one of claims 1 to 4, wherein during operation, the at least one processor determines a plurality of AC electrical parameters at least in part based on the voltage sensor signal and the current sensor signal. [Claim 6] A non-contact measurement system according to any one of claims 1 to 5, further comprising a display operably coupled to the at least one processor, wherein, when in operation, the at least one processor causes the display to show the at least one AC electrical parameter. [Claim 7] The non-contact measurement system according to claim 6, wherein, during operation, the at least one processor causes the display to show at least one of a waveform or graph related to the at least one AC electrical parameter. [Claim 8] A non-contact measurement system according to any one of claims 1 to 7, further comprising a communication interface operably coupled to the at least one processor, wherein, during operation, the at least one processor sends data via the communication interface to at least one external device, the data relating to the voltage sensor signal, the current sensor signal, or at least one of the at least one AC electrical parameter. [Claim 9] The non-contact measurement system according to claim 8, wherein the communication interface includes a wireless communication interface capable of wirelessly transmitting the data to the at least one external device. [Claim 10] The non-contact measurement system according to any one of claims 1 to 9, wherein the indicator device includes at least one of a visual indicator device or an audible indicator device. [Claim 11] The non-contact measurement system according to any one of claims 1 to 5, wherein the indicator device includes at least one of a display or a plurality of illumination units, and when in operation, the at least one processor causes the indicator device to provide the operator with the alignment indicator including a plurality of colors, each of the plurality of colors corresponding to a different degree of alignment of the insulated wire with respect to the receiving unit. [Claim 12] The non-contact measurement system according to any one of claims 1 to 11, wherein the indicator device includes a visual indicator device, and during operation, the at least one processor causes the indicator device to provide a color-coded display of measurement accuracy based at least in part on the alignment feedback sensor signal. [Claim 13] A method performed by a non-contact measurement system for measuring voltage or current in an insulated wire without direct electrical contact with the insulated wire, wherein the non-contact measurement system comprises a housing; a voltage sensor that is physically coupled to the housing and can be selectively positioned in close proximity to the insulated wire without electrical contact with the insulated wire; an internal earth guard made of a conductive material, at least partially surrounding the voltage sensor and electrically insulated from the voltage sensor, and sized to shield the voltage sensor from stray currents; and a reference shield made of a conductive material, at least a portion of the housing and electrically insulated from the internal earth guard, and sized to reduce the current between the internal earth guard and external earth, Receiving an alignment feedback sensor signal indicating the current alignment of an insulated wire with respect to the receiving portion of the front end located between the first and second ends, from at least one of a first alignment feedback sensor located near the first end portion of the front end of the housing of the non-contact measurement system and a second alignment feedback sensor located near the second end portion of the front end of the housing of the non-contact measurement system, via at least one processor provided within the housing of the non-contact measurement system, wherein the alignment feedback sensor signal is generated in response to the detection of voltage within the insulated wire when the insulated wire is positioned near the receiving portion, and the housing further includes a gripping portion that is grasped by the operator of the non-contact measurement system during measurement, in addition to the front end. The at least one processor causes an indicator device provided on the surface of the housing of the non-contact measuring system to provide the operator of the non-contact measuring system with an alignment indicator based at least partially on the alignment feedback sensor signal, wherein the alignment indicator displays and provides the degree of alignment of the insulated wire with respect to the receiving portion. A common-mode reference voltage source electrically coupled between the internal earth guard and the reference shield generates an alternating current (AC) reference voltage having a reference frequency. The voltage sensor provided within the housing of the non-contact measurement system detects a signal indicating the voltage within the insulated wire during the measurement time interval without directly making electrical contact with the insulated wire. The current sensor provided within the housing of the non-contact measurement system detects a signal indicating the current in the insulated wire during the measurement time interval without directly making electrical contact with the insulated wire. A method comprising determining, via at least one processor, at least in part, an alternating current (AC) electrical parameter based on the sensed voltage and the sensed current, and also on the human body capacitance, which is the operator's capacitance to ground when the operator grasps the gripping portion in the non-contact measuring system. [Claim 14] The method according to claim 13, wherein sensing the voltage includes sensing the voltage using a capacitive voltage divider type voltage sensor, and sensing the current includes sensing the current using a magnetic field sensor. [Claim 15] The method according to claim 13 or 14, wherein determining at least one AC electrical parameter includes determining at least one of power, phase, frequency, harmonics, or energy based at least in part on the sensed voltage and the sensed current. [Claim 16] The method according to any one of claims 13 to 15, further comprising showing the operator of the non-contact measurement system a display of at least one AC electrical parameter. [Claim 17] A non-contact measurement system for measuring voltage or current within an insulated wire without directly making electrical contact with the insulated wire, A housing including a front end comprising a first end portion, a second end portion, and a receiving portion between the first and second end portions, and a gripping portion that is held by the operator of the non-contact measuring system during measurement, A first alignment feedback sensor for the first end portion and a second alignment feedback sensor for the second end portion, wherein, during operation, each of the first and second alignment feedback sensors detects the voltage within the insulated wire when the insulated wire is positioned near the first and second alignment feedback sensors, and in response generates an alignment feedback sensor signal indicating the current alignment of the insulated wire with respect to the receiving portion, Indicator device and A voltage sensor, located near the front end of the housing, detects a voltage sensor signal indicating the voltage within the insulated wire during operation, without directly making electrical contact with the insulated wire. A current sensor, located near the front end of the housing, detects a current sensor signal indicating the current in the insulated wire during operation, without directly making electrical contact with the insulated wire. The housing comprises at least one processor, An internal grounding guard, which at least partially surrounds the voltage sensor and is directly electrically coupled to the internal electrical ground of the non-contact measuring system, is made of a conductive material and has dimensions such that it shields the voltage sensor from stray currents. A reference shielding body that surrounds at least a portion of the housing and does not make direct electrical contact with the internal earth guard, and is made of a conductive material that capacitively couples with the external earth, and is sized to reduce the current between the internal earth guard and the external earth. A common-mode reference voltage source electrically coupled between the internal earth guard and the reference shield, comprising a common-mode reference voltage source that generates an AC reference voltage having a reference frequency during operation, During operation, the at least one processor, The alignment feedback sensor signal indicating the current alignment of the insulated wire with respect to the receiving portion is received, The indicator device is made to provide an alignment indicator, which shows the degree of alignment of the insulated wire with respect to the receiving portion, based at least partially on the alignment feedback sensor signal. The voltage sensor signal acquired by the voltage sensor during the measurement time interval, which indicates the voltage in the insulated wire, is received from the voltage sensor. The current sensor signal acquired by the current sensor during the measurement time interval, which indicates the current in the insulated wire, is received from the current sensor. A non-contact measurement system that determines at least one alternating current (AC) electrical parameter based at least in part on the voltage sensor signal and the current sensor signal, and also on the human body capacitance, which is the operator's capacitance to ground when the operator grasps the gripping portion of the non-contact measurement system.

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