Testing of XLPE Cable above 33KV up to 220KV

Type Tests for XLPE Copper Cable Tests on Conductor Tests on Insulation Tests on Semiconductor Layer on the Insulation Tests on Metallic Screen Tests on Metallic Sheath Tests on Armours Tests on Outer Sheath Tests on Complete Cable Specimen Routine Tests on XLPE HV Cables Acceptance Tests on XLPE HV Cables

Ferroresonance in Potential Transformer

As the name suggests, ferroresonance is a resonance phenomenon related to iron. Ferro means ‘iron’. Before understanding the ferroresonance, let us recall the concept of resonance first. Suppose, we have a series RLC circuit, across which a voltage source is connected. Say a current I flowing through the circuit. VL is the voltage developed across … Read more

Amorphous Core for Distribution Transformer – Advantages

In general a cold rolled grain oriented (CRGO) silicon steel is used for the core of a distribution and station service transformers. Nowadays, there is another type of material used for core of distribution transformers and sometimes station service transformers. This is modern trend of core materials. This is amorphous iron material. Amorphous core material … Read more

Earth Continuity Cable (ECC) for EHV Cables

Single-core cables are the most commonly used cables for underground high-voltage transmission systems. This is because 3-core high-voltage transmission cables, mainly above 33kV, are not easily transportable due to their very thick insulation and weight. A single-core cable is lighter than a three-phase or 3-core cable. The insulation of these single-core cables is covered with … Read more

Type, Routine and Acceptance Tests for High Voltage XLPE Cables

Type Tests for above 33KV up to 220KV XLPE Copper Cable Tests on Conductor Tests on Insulation 3. Measurement of Thickness of Insulation4. Measurement of tensile strength and elongation at break5. Thermal ageing in air oven6. Hot set test7. Shrinkage test8. Void and contaminants test Tests on semiconductive layers of the insulation 9. Resistivity test … Read more

Parameters of 10MVA 66/11KV Transformer

The clearance requirements for HV and LV terminals in the air are as follows:For 66 kV side, the phase-to-phase and phase-to-earth clearance should be 700 mm, and 660 mm respectively.For 12 kV side, the phase-to-phase and phase-to-earth clearance should be 280 mm, and 140 mm respectively. The following points should be noted for designing winding … Read more

Top Interview Questions on Voltage Transformer

What is the Rated Voltage Factor in voltage transformers, and how is it determined?This is the ratio of the maximum operating voltage to the rated primary voltage of the PT. This factor is to be multiplied with the primary rated voltage to determine the maximum operating voltage of the PT at which the PT can … Read more