6/19/2023 0 Comments Change peak picking in inmr to hzSince insulation properties are temperature dependent, temperature correction is commonly used for measurements not performed at 20☌. Analysis is based on standards, historical data and comparison against factory values. There are also tests with variable voltage (tip-up/step-up testing) as well as tests where tan delta over temperature is measured. DF tests are typically done at ‘any’ temperature using a test voltage from about 30 V up to about 10 kV for field tests and up to nominal voltage in factory measurements. This is the standard test performed whenever there is a need to investigate insulation properties. Manufacturer of long rod insulators, line post insulators, station post insulators, hollow core insulators and many other composite products as per customer specifications.Ī common insulation diagnostic test is measurement of capacitance and dissipation factor (DF) at 50/60 Hz. We produce and test reliable products to international standards (IEC, ANSI, BS, DIN, AS). CTC Insulators has the quality certification ISO9001. World Class supplier of Composite insulators established in 2002 in Dalian, China. Adding just a few more years to the expected end-of-life of a transformer or bushing can yield substantial savings. On the other hand, it’s also important to identify ‘good’ units in the ageing population of equipment. Moreover, bushings and cables with high dissipation factor at high temperature can explode due to ‘thermal runaway’. Transformers with high moisture content cannot sustain high loads without elevated risk. The condition of insulation is essential to ensuring operational reliability of transformers, generators, cables and other high voltage equipment. It also explained how these can improve understanding of insulation properties and be used for assessing condition of insulation on bushings and instrument transformers. This edited past contribution to INMR by experts at Megger in Sweden, provided a background on DFR as well as on insulation modeling. Since the modeling theory contains influence of temperature, DFR and modeling can also be used to calculate temperature dependence of the insulation system. DFR data, in combination with mathematical modeling of the oil/paper insulation, has proven to be an excellent tool for moisture assessment. Dielectric frequency response or DFR, (also known as Frequency Domain Spectroscopy or FDS), was introduced over 25 years ago and has been evaluated in research projects and field tests, usually with good results. Of particular interest are dielectric response measurements where insulation properties of oil/paper systems can be investigated. Modern technology in signal acquisition and analysis techniques has provided new tools for transformer diagnostics.
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