Power transformers are among the most critical components in today’s transmission and distribution infrastructure.
Unexpected transformer failures can lead to significant financial losses due to unscheduled maintenance and power outages. Therefore, it is essential to make testing and diagnostics both reliable and efficient to ensure long-term system stability.
Sweep Frequency Response Analysis (SFRA) is a powerful and highly sensitive diagnostic method used to evaluate the mechanical integrity of the transformer core, windings, and clamping structures. By measuring the transformer’s electrical transfer function over a wide frequency range, SFRA detects subtle internal changes that may not be visible through conventional tests. Moreover, this method provides early detection of mechanical issues, reducing unexpected downtime.
Adiradh Energy offers the FRAX Series Sweep Frequency Response Analyzer, including models FRAX101, FRAX99, and FRAX150. These instruments detect both mechanical and electrical deviations in transformer cores and winding assemblies. The system captures a unique fingerprint of each transformer and compares it with previous measurements or reference data. Consequently, any deviation clearly indicates geometrical or electrical changes within the transformer structure.
Sweep frequency response analyser-Frax 101
Ordering Information for FRAX 101 in India
FRAX-101 with accessories, 18 m cable set – Art. No: AC-19090
FRAX-101 with accessories, 9 m cable set – Art. No: AC-19092
FRAX-101 with accessories including battery, 18 m cable set – Art. No: AC-19091
FRAX-101 with accessories including battery, 9 m cable set – Art. No: AC-19093
Sweep Frequency Response Analyzer -Frax 99
Ordering Information for FRAX 99 in India
FRAX-99 with accessories, 18 m cable set – Art. No: AC-29092
FRAX-99 with accessories, 9 m cable set – Art. No: AC-29090
FRAX-99 with accessories including battery, 18 m cable set – Art. No: AC-29096
FRAX-99 with accessories including battery, 9 m cable set – Art. No: AC-29095
Sweep Frequency Response Analyzer-FRAX 150
Ordering Information for FRAX 150 in India
FRAX-150 with accessories, 18 m cable set – Art. No: AC-39090
FRAX-150 with accessories, 9 m cable set – Art. No: AC-39092
Brochure for Sweep Frequency Response Analyzers SFRA FRAX101-FRAX99-FRAX150
SFRA detects problems
SFRA FRAX Series Key features
These networks produce a distinctive electrical signature when tested across various frequencies. The Sweep Frequency Response Analyzer (SFRA) measures this signature by plotting the frequency response curve, which helps detect internal mechanical or electrical changes efficiently.
The FRAX Series from Adiradh Energy offers advanced features such as:
Frequency range: 0.1 Hz to 25 MHz (user-selectable)
Dynamic range: over 130 dB
Wireless communication for convenient operation
To ensure test accuracy, international FRA standards recommend verifying the integrity of cables and instruments before and after each test. The FRAX analyzer includes a Field Test Box (FTB101) as a standard accessory, allowing on-site validation and ensuring reliable, high-quality measurements at all times.
Sweep frequency response curve -SFRA curve
Standards for Sweep Frequency Response Analyzer
The IEEE guide for SFRA is IEEE C57.149 – Guide for the Application and Interpretation of Frequency Response Analysis for Oil-Immersed Transformers. Other relevant SFRA documents include:
IEC60076-18 Ed.1 – 2012
DL/T911-2004
Cigré Technical Brochure No. 342, April 2008
The power factor or tan delta test, traditionally performed only at 50 Hz, is a valuable method for assessing the condition of transformer insulation systems. However, this single-frequency approach has limitations. Many of these can be overcome by conducting measurements over a range of frequencies, providing deeper diagnostic insights.
Another lesser-known test, the short-circuit impedance measurement, evaluates winding deformation by analyzing leakage reactance. When performed at several frequencies—typically between 1 Hz and 500 Hz—and focused on the resistive component, it yields valuable diagnostic information known as the Frequency Response of Stray Losses (FRSL) technique.
It’s important not to confuse Dielectric Frequency Response (DFR) or FRSL with Sweep Frequency Response Analysis (SFRA). While SFRA identifies mechanical changes in transformer cores and windings, DFR determines the moisture content in cellulose insulation. Both tests serve different diagnostic purposes.
The Adiradh FRAX Series SFRA test set enhances this process by providing FRSL results concurrently with SFRA short-circuit measurements, enabling a more complete and accurate evaluation of transformer health.
Adiradh Energy offer Sweep frequency response analysers FRAX99, FRAX150,FRAX101 in India; Hyderabad; Visakhapatnam; Vijayawada; Chennai; Puducherry; Trichy; Coimbatore; Hosur; Bangalore; Hubli; Mysore; Cochin; Kolkata; Pune; Goa; Mumbai; Thane; Kanpur; Jaipur; Nagpur; Delhi; Noida; Gurugam; Bhopal; Vadodara; Ahmedabad;Chandigarh;Chandigarh;Tata Nagar; Raipur; Rudrapur;; Durgapur; Kharagpur;Raigarh; Bhilai;Angul; Haldia;Jabalpur;Indore; Jamshedpur; Rajahmundry; Bokaro Steel City;salem;kochi; Rourkela; Ahmedabad ;Jamnagar; Bharuch; Sri City ; Nashik;Haridwar; Mathura;Aurangabad; Bhubaneswar and other cities
Adiradh Energy Pvt.Ltd
Lakshmi Nilayam, #15-29-887/C2,
Rd Number 2, Kukatpally Housing Board Colony,
Hyderabad, Telangana 500072
Mobile : 9440761200
Land line : 04023051200
info@adiradh.com
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