Optical Voltage Transformer Based on FBG-PZT for Power Quality Measurement

Area of Science:

• Electrical Engineering
• Optoelectronics
• Power Systems

Background:

• Optical Current Transformers (OCTs) and Optical Voltage Transformers (OVTs) offer advantages over conventional transformers, including smaller size and weight.
• While their use for protection and metering is established, research on their application for power quality monitoring remains limited.

Purpose of the Study:

• To develop and evaluate a temperature-independent optical voltage transformer (OVT) prototype for power quality monitoring.
• To assess the OVT's capability in detecting voltage disturbances on 13.8 kV distribution lines.

Main Methods:

• Construction of a prototype OVT utilizing fiber Bragg grating (FBG) and piezoelectric ceramics (PZT).
• Testing the OVT prototype under various power system disturbances, including SAG, SWELL, and INTERRUPTION, as per IEEE standards.
• Evaluation of the OVT's harmonic and impulsive surge reproduction capabilities.

Main Results:

• The developed OVT demonstrated a dynamic response suitable for measuring short-duration voltage variations like SAG, SWELL, and INTERRUPTION.
• The prototype successfully reproduced harmonics up to the 41st without significant distortion and impulsive surges up to 2.5 kHz.
• The OVT proved effective as a power quality monitor for a 13.8 kV distribution system.

Conclusions:

• The proposed temperature-independent OVT is a viable tool for field surveys and power quality monitoring in distribution systems.
• The OVT's remote monitoring capability and lack of need for electrical power offer significant advantages over conventional systems.
• This technology enables strategic placement on distribution lines for effective, long-distance power quality assessment.