NxtPhase - Products - Optical Current - NXCT Optical Current Sensors


	NXCT Specifications (135 KB)
	Optical CT & VT Brochure (886 KB)

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	Opto-electronic modules provide complete signal processing for NxtPhase VTs & CTs. More...
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Optical Current Sensor
Demonstration




Optical CT & VT Articles (current & voltage)
T&D Innovation		Optical Technology: A New Generation of Instrument Transformer
Transmission & Distribution		Move Over CTs and PTs
The NxtPhase Optical Current Sensor replaces conventional CTs & bring a new level of accuracy to current sensing over the range of 1A(rms) to 63kA(rms), from 138 kV to 500 kV. The sensor is based on the Honeywell Fiber Optic Gyro system which has a trusted reputation for accuracy & reliability in aeronautic & space industries for both commercial & military applications. The sensor can be column mounted on an advanced polymeric insulating column, or bus mounted with a suspension insulator to bring the optical fiber to ground.

New Features!

Dry type insulator
Improved head design
Now available in NEMA, dual cable & rigid bus kits!

The reduced size & weight compared to conventional oil-filled equipment allows placement in compact substations, or in retrofit applications where space may be limited. The broad dynamic range means the NXCT is particularly suited to independent merchant plants which demand extreme accuracy at both full power output & station service draw.

Powerlines Feature Article:

Protection of a 230 kV Line Using Both Conventional & Optical CT Inputs at Arizona Public Service

Technical Papers

Reliability Considerations: Optical Sensors for the Control & Measurement of Power (235 KB)
Optical Current Transducers for High Voltage Applications (113 KB)
Fiber Optic Current Sensor Calibration (206 KB)
A Wide-Band High-Accuracy SF6-Free Optical Voltage Transformer (20 KB)
Optical Current Transducers for High Voltage Applications (179 KB)
Optical Current Sensors Eliminate CT Saturation (711 KB)
Portable Fiber Optic CT for Field Calibration Applications (47 KB)
Design Options Using Optical Current & Voltage Transducers in High Voltage Substation (1079 KB)

NXCT Advantages for Power Transmission & Distribution:

Utility Metering & Protection Accuracy
The NXCT design permits measurements to be made with the highest possible accuracy & stability. The performance exceeds IEC Class 0.2S & IEEE Class 0.3 accuracy requirements to address stringent revenue metering requirements. The NXCT also exceeds IEC Class 5P accuracy allowing the same device to be used for relaying & utility metering applications, eliminating the need for separate metering & relaying instrument transducers.

Wide Dynamic Range
The accuracy specification is maintained over a broad dynamic range - from 5% to 200% of rated current. By special order, this range can be extended below 1% of rated current. This allows elimination of separate high & low range CTs.

High Bandwidth
Accurate waveform reproduction from DC to 10kHz allows full power quality analysis of harmonics & transients with no sensor-imposed limitations.

Light Weight Composite Insulator
Both the pedestal mounted & bus-mounted versions are available. Field -proven lightweight composite insulator reducing transportation costs, substation support structure requirements & installation equipment demands. The light weight design allows location in seismically active areas.

Intrinsically Safe, Environmentally Friendly Design
The insulators do not contain mineral oil and cellulose insulations, or SF6 gas. There is no internal mechanism for violent failure to endanger personnel or adjacent equipment. There are no environmental concerns or gas to recycle. With an optical design there is no concern with open secondaries.

Low Maintenance
The NXCT has no active components at line potential eliminating the need for costly outages to maintain the electronics. Since there is no insulating oil or paper there are no complex maintenance procedures. The polymeric insulating column employs silicone rubber sheds that do not require live-line washing.