Power Substation
What does a good grounding of the power substation and switching station really mean?
Provision of adequate grounding in a substation and switching stations are very important for the safety of operating personnel as well a electrical devices do not rise above tolerable thresholds and that the earth connection is rugged to dissipate the… Read more
Dec 18, 2017 | By Edvard Csanyi
Protection
Primary injection testing of protection system for wiring errors between VTs / CTs and relays
This type of test involves the entire circuit – current transformer primary and secondary windings, relay coils, trip and alarm circuits, and all intervening wiring are checked. There is no need to disturb wiring, which obviates the hazard of open-circuiting… Read more
Dec 13, 2017 | By Edvard Csanyi
Protection
Secondary injection tests for checking the correct operation of the protection scheme
Secondary injection tests are always done prior to primary injection tests. The purpose of secondary injection testing is to prove the correct operation of the protection scheme that is downstream from the inputs to the protection relay(s). Why done prior… Read more
Nov 22, 2017 | By Edvard Csanyi
Protection
Commissioning Numerical Protection and Procedure For Carrying Out Performance Tests
Numerical protection is based on a number of microprocessors that can be programmed to reproduce virtually any type of protection and relay. It represents important advantages in reliability, space and economics compared to conventional protection arrangements. The method of calculating… Read more
Oct 30, 2017 | By Edvard Csanyi
Power Substation
3 greatest enemies to the transformer operation (and how to prevent them)
The principal object of transformer maintenance is to maintain the insulation in good condition. Moisture, dust and excessive heat are the main reasons of insulation deterioration and avoidance of these will keep insulation in good condition. Heat and contamination are… Read more
Jul 28, 2017 | By Edvard Csanyi
Maintenance
How do faults develop in a HV transformer and why condition monitoring is important
Condition monitoring equipment that can be used to extend the life of a transformer or to prevent catastrophic failure could pay for itself many times over. However, condition monitoring does not come free of charge, and tight budgets are to… Read more
Jul 10, 2017 | By Edvard Csanyi
Protection
Pre-commissioning tests and in-service checks of protection system
The pre-commissioning tests need to be carefully programmed so that they take place in a logical and efficient order, in order that no equipment is disturbed again during subsequent tests. Before starting the tests, it is essential to ensure that… Read more
Jun 14, 2017 | By Edvard Csanyi
Testing and Commissioning
Commissioning substation busbars in an efficient and modern way
The commissioning procedure of substation busbars for differential protection and other busbar protection schemes involves a large number of input and output circuits that require a verification check in both the primary and secondary circuits. This large amount of data… Read more
Jun 13, 2017 | By Edvard Csanyi
High Voltage
Generation of high voltages in the lab (AC/DC, switching and lightning impulse)
Benjamin Franklin – The man who dared to fly his kite in a thunder storm! In this technical article laboratory tests and test equipment needed to assess the performance of insulating materials and equipment are discussed. Laboratory testing attempts to… Read more
May 29, 2017 | By Edvard Csanyi
Industrial Automation
PLC power supply and safety (emergency) circuits requirements
The source for a PLC power supply is generally single-phase and 120 or 240 VAC. If the controller is installed in an enclosure, the two power leads (L1 hot and L2 common) normally enter the enclosure through the top part… Read more
Mar 15, 2017 | By Edvard Csanyi
Maintenance
Performing power factor test on dry-type transformer during commissioning
The power factor test is a maintenance test used to determine the insulation system dielectric power loss by measuring the power angle between an applied AC voltage and the resultant current. Power factor is defined as the ratio of the… Read more
Mar 01, 2017 | By Edvard Csanyi
Low Voltage
Measurement of N–PE loop resistance in TN, TT and IT systems
Up-to-date test instruments, with built in modern electronics, can measure loop resistance even between the neutral N and protection PE conductors in spite of possible high currents in the neutral conductor. The current, which is driven by phase voltages through… Read more
Feb 24, 2017 | By Edvard Csanyi
Cables
Guidelines for high potential (Hi-Pot) DC testing of medium voltage cables
This technical article provides general guidelines for high potential “Hi-Pot” DC testing of MV power cables. All tests made following cable installation and during the warranty period must be performed in accordance with the applicable specifications. Testing should be performed… Read more
Feb 20, 2017 | By Edvard Csanyi
Energy and Power
The easiest way to measure ground resistance using clamp meter, but be carefull!
The ground clamp meter / tester is an effective and time-saving tool when used correctly because the user does not have to disconnect the ground system to make a measurement or place probes in the ground. The method is based… Read more
Feb 06, 2017 | By Edvard Csanyi
Maintenance
Transformer exterior inspection and tests you MUST perform periodically
Periodic transformer exterior inspection (visual) reveals important condition information. For example, valves positioned incorrectly, plugged radiators, stuck temperature indicator and level gauges, and noisy oil pumps or fans. Oil leaks can often be seen which indicate a potential for oil… Read more
Jan 25, 2017 | By Edvard Csanyi
