Speaker: Charles Sweetser, OMICRON electronics Corp. USA
Testing voltage transformers (VTs) or also referred to as potential transformers (PTs), has always been a challenging task. Application and technology applied can vary. Test plans, test procedures, and analysis of the results must be executed correctly if we are to determine and continually track the condition of VT/PT instrument transformers. It is important to understand the need, value, and application of comprehensive testing of PT/VT instrument transformers.
This paper will focus on both inductive and coupling capacitor (CCVT) PT/VT instrument transformers, including theory and practice. Both L-L and L-G configurations with be included, as well as recommended test voltages and settings. We will investigate the best practices regarding test procedure, test preparation, and the analysis of the results.
The following standard electrical field tests will be included in the discussion:
- Power Factor
- Cross Check
- Exciting Current
- Voltage Ratio
The audience will be provided with an understanding of the application, and analysis of these best practices, supported by specially selected case studies validating the value that these diagnostic tests bring to testing, and finally assessing, PT/VT instrument transformers.