scholarly journals Frequency Response Analysis Technique of Short Circuit Faults Detection in Photovoltaic Single-Phase Inverter Experimental Study

2021 ◽  
Vol 23 (4) ◽  
pp. 337-343
Author(s):  
Ouadfel Ghania ◽  
Houassine Hamza ◽  
Gacemi Abderzak ◽  
Bensaid Samir

The work proposed in this paper concerns the study of short circuit faults in a single-phase inverter dedicated to a photovoltaic application by applying the frequency response analysis (FRA) technique on this IGBT-based inverter controlled by a 18F2550 microcontroller, a prototype inverter was designed in the laboratory to be able to apply off-line short-circuit faults using an LRC meter. The FRA technique is based on the comparison of amplitude-frequency and phase-frequency signatures of healthy cases and fault situations. The experimental results also led to the conclusion that frequency response analysis can be used as an effective tool to detect faults in power electronic devices. This method allows for efficient detection and classification of faults with ease of implementation. For fault location, the fault branch is determined according to its position relative to its healthy state.

Author(s):  
Nilanga Abeywickrama

Power transformers encounter mechanical deformations and displacements that can originate from mechanical forces generated by electrical short-circuit faults, lapse during transportation or installation and material aging accompanied by weakened clamping force. These types of mechanical faults are usually hard to detect by other diagnostic methods. Frequency response analysis, better known as FRA, came about in 1960s (Lech & Tyminski 1966) as a byproduct of low voltage (LV) impulse test, and since then has thrived as an advanced non-destructive test for detecting mechanical faults of transformer windings by comparing two frequency responses one of which serves as the reference from the same transformer or a similar design. This chapter provides a background to the FRA, a brief description about frequency response measuring methods, the art of diagnosing mechanical faults by FRA, and some case studies showing typical faults that can be detected.


2021 ◽  
Vol 11 (7) ◽  
pp. 2923
Author(s):  
Salem Mgammal Al-Ameri ◽  
Muhammad Saufi Kamarudin ◽  
Mohd Fairouz Mohd Yousof ◽  
Ali A. Salem ◽  
A. Abu Siada ◽  
...  

Frequency response analysis (FRA) is a method of monitoring a power transformer’s mechanical integrity. However, identifying the type of fault and its severity by comparing measured responses is still challenging and mostly relies on personnel expertise. This paper is taking one step forward to standardize the FRA interpretation process by proposing guidelines based on various international standards and FRA case studies. In this study, the FRA signature is divided into three regions: low-, mid- and high-frequency regions. The deviation from the fingerprint signature for various faults is classified into small, large, and no variations, based on the calculation of the correlation coefficient. The proposed guidelines are developed based on the frequency regions, and the level of variation is represented using a simple arrow method to simplify the interpretation process. A case study is conducted on a three-phase 11/0.433 kV, 500 kVA distribution transformer with a short circuit winding fault to validate the proposed guidelines.


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