High Voltage Direct Current (HVDC) Few weeks back I posted an article about advantages of HVDC over HVAC transmission systems. Advantages of HVDC are numerous and very well recognized, but like everything on this earth this system has other side too. The eight main disadvantages of HVDC transmission systems, including DC links connecting HVAC systems area, […]
Electrical Thumb Rules You MUST Follow (Part 7)
Continued from: Electrical Thumb Rules You MUST Follow (Part 6) 8 electrical thumb rules to follow: Overhead conductor / cable size Transmission / distribution line (span, height of tower) Types of towers Tower swing angle clearance (metal part to live part) Cable coding, IS 1554 (A2XFY, FRLS, FRPVC, FRLA, PILC) Corona ring size Load as per […]
Advantages of HVDC over HVAC transmission
AC as preferred option Despite alternating current being the dominant mode for electric power transmission, in a number of applications, the advantages of HVDC makes it the preferred option over AC transmission. Examples include: Undersea cables where high capacitance causes additional AC losses (e.g., the 250-km Baltic Cable between Sweden and Germany). Endpoint-to-endpoint long-haul bulk […]
15 hypothesis responsible for the aging of composite insulators
Major causes of aging in composite insulators Most technical work concentrates on the aging of nonceramic insulators and the development of test methods that simulate the aging process. Transmission lines operate in a polluted atmosphere. Inevitably, insulators will become polluted after several months in operation. Fog and dew cause wetting and produce uneven voltage distribution, […]
General principles of electricity supply systems
Transmission of electricity The generation of electricity in most modern power stations is at 25 kV, and this voltage is then transformed to 400 kV for transmission. Virtually all the generators of electricity throughout the world are three-phase synchronous generators. The generator consists of a prime mover and a magnetic field excitor. The magnetic field […]
Special Transformers for Industrial Applications
Specific Industrial Transformers A number of industry applications require specific industrial transformers due to the usage of power (current) as a major resource for production. Electric arc furnace transformers (EAF) DC electric arc furnace transformers (DC EAF) Rectifier transformers Converter transformers Line Feeder Electric arc furnaces (EAF), ladle furnaces (LF) and high-current rectifiers need a […]
Talking About HV Shunt Reactor Switching (part 2)
Continued from first part: Talking About HV Shunt Reactor Switching (part 1) Content Scope (explained in previous part) Shunt reactors application (explained in previous part) Closing operation (explained in previous part) Opening operation Conclusions Opening operation In the case of shunt reactors the current to be interrupted are very low (typically less than few hundreds […]
Talking About HV Shunt Reactor Switching (part 1)
Content Scope Shunt reactors application Closing operation Opening operation (in next part) Conclusions (in next part) Scope These notes aim to give basic idea of the main criticalities related to HV shunt reactor switching, particularly in terms of voltage, and how such problems are faced and solved by modern switching technology. Go to Content ↑ Shunt reactors […]
Commissioning of HV Panel – Operational and Functional Checkup
Main Objective The main objective of the test is to check the proper operation function of the circuit breaker; in this test we do the following: A. Close Operation Test – Local—Remote This test is conducted by manual, Local and Remote. For the manual Operation test, we will charge the spring manual and breaker is […]
High voltage testing – Direct current (DC)
DC Tests DC tests are used mainly to do “pressure tests” on high voltage cables. Although the cables operate with AC, AC testing is not practical. The high capacitance of the cables necessitates AC test sets with a high kVA rating to be able to supply the capacitive current. In the case of DC, once the […]
