HVDC stands for High Voltage Direct Current. An HVDC electric power transmission system uses direct current for the bulk transmission of electrical power, in contrast with the more common alternating current systems. For long-distance distribution, HVDC systems are less expensive and suffer lower electrical losses. For shorter distances, the higher cost of DC conversion … [Read more...] about What is an HVDC (High Voltage Direct Current) Transmission System?
Insulation Resistance or IR Test is carried out by maintenance engineers to ensure the healthiness of the overall insulation system of electrical equipment. It reflects the presence or absence of harmful contamination, dirt, moisture, and gross degradation. IR value will be usually high (several hundred Megaohms) for a dry insulation system. Maintenance engineers use … [Read more...] about Insulation Resistance Test (IR Test) or Megger Test
The effects of voltage and frequency variation on the transformer is discussed in this article. Usually, power transformers are not subjected to wide frequency variations. Also, modest voltage variations occur on power transformers. But it is interesting to consider their effects thereof. Variation of voltage and frequency affects the iron losses (hysteresis and eddy current … [Read more...] about Effects of Voltage and Frequency Variation on Transformers