Electric Motor
Protecting Motor From External Network Disturbances (Unbalance, V/Hz-ratio and Re-Energizing)
Unbalance in the supply voltage is typically due to a broken phase condition somewhere in the upstream network. This may result from single-phase fuse failure or pole discrepancy of a circuit breaker or a disconnector. In addition, unequal loading of… Read more
Jan 29, 2018 | By Edvard Csanyi
Energy and Power
How to control and protect capacitor banks before something goes wrong
The purpose of a capacitor bank’s protective control is to remove the bank from service before any units or any of the elements that make up a capacitor unit are exposed to more than 110% of their voltage rating. When… Read more
Jan 24, 2018 | By Edvard Csanyi
Protection
Recommended and commonly applied protection for transformers
The protection that is recommended and commonly applied for transformers is summarized in the following figures. It should be noted and recognized that these are general recommendations, not strict. More or less protection may be applied for any specific situation… Read more
Jan 12, 2018 | By Edvard Csanyi
Electric Motor
Protection Of Industrial Power Supply Systems (Fuses, MCCBs and Overcurrent Relays Settings)
As industrial operations processes and plants have become more complex and extensive, the requirement for improved reliability of electrical power supplies has also increased. The potential costs of outage time following a failure of the power supply to a plant… Read more
Jan 02, 2018 | By Edvard Csanyi
Power Substation
Three Bad Conditions That Cause False Differential Current In Power Transformer
When applying differential protection of power transformer, three bad conditions must be considered which can lead to unbalance to the currents applied to the relay (compared with the expected currents when power flow into the transformer is equal to the… Read more
Dec 27, 2017 | By Edvard Csanyi
Electric Motor
10 Common Questions You Can Expect In Electrical Engineering Examination Test
This examination will focus on testing the fundamentals of electrical engineering from low voltage to high voltage. Of course, you can use huge EEP’s resources for help in calculations and finding right answers. Ok, let’s start with questions. You can… Read more
Dec 26, 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
Energy and Power
Protections For Medium Voltage Synchronous Machines (Generators) – IEEE C37-2 Codes
The protection system for MV generators (synchronous machines) must be carefully selected and studied for the application it is destined for and it is not normally possible to define a single solution. Only medium voltage generators are analysed and large… Read more
Dec 04, 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
Differential Protection Of Feeders For Transformers And Tee-Offs (Tapped Lines)
On transformer feeders, the transformer and line or cable are connected in series and form a unit. In this manner, one CB can be saved. On feeders with tee-offs, transformers along the feeder are directly connected. In this case, a… Read more
Nov 20, 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
Protection
Differential protection of transformers, machines, busbars, lines and feeders
Differential protection is very useful method of protection that can be applied to the protection of any network component, such as transformers, machines, busbars, lines and feeders. The differential relay compares the incoming phase currents of an object to the… Read more
Oct 16, 2017 | By Edvard Csanyi
Energy and Power
The Structure of Electric Power Systems: Energy Generation, Distribution and Transmission
From a general perspective, an electric power system is usually understood as a very large network that links power plants (large or small) to loads, by means of an electric grid that may span a whole continent, such as Europe… Read more
Oct 09, 2017 | By Edvard Csanyi
High Voltage
Seven design diagrams that every HV substation engineer MUST understand
A substation engineer should have a good understanding of the electrical equipment and layout of HV power substation. It’s also important to understand relationship between protection and the other equipment in the substations and the distribution system. Beside this, it’s… Read more
Oct 04, 2017 | By Edvard Csanyi
Energy and Power
Rules for power distribution in LV switchgear and protection of branch / distributed lines
In designing a power distribution concept, encompassing the sizing of systems and devices, it is essential to align the requirements and feasibility with both the end user and the manufacturer. The appropriate sizing of low-voltage switchgear necessitates an understanding of… Read more
Sep 20, 2017 | By Edvard Csanyi
