Protection & Relay Engineering

Protection Relay Testing, Coordination and Automatic Reclosing

Safe and uninterrupted power flow depends on correct protection settings and thorough testing. We provide the full engineering chain, from system analysis through to commissioning and reporting.

Short-Circuit and Load Flow Analysis

Before any relay is configured, we analyse the power system in detail. Short-circuit and load flow calculations establish the protection levels appropriate to the fault scenarios your system can encounter. These calculations are the basis of relay coordination and of keeping the risk of unwanted tripping to a minimum.

Relay Settings

Using the values established by the analysis, we configure and validate the protection settings on site. Each relay is set according to your requirements and the specific conditions of the installation. Correct settings protect the system during faults while avoiding nuisance tripping.

Functional Testing

Once settings are applied, we carry out functional testing on site with dedicated secondary injection equipment, verifying that each relay responds correctly at the defined current, voltage and time values.

Testing covers the time–current characteristic curves and both instantaneous and time-delayed trip settings. Every protection scenario is simulated against the relay curves and the response is checked at the specified values.

We test each protection function separately — phase protection, earth fault, unbalance, over- and under-voltage and overcurrent tripping. Trip times are verified against tolerance and, where required, settings are refined so that the relay operates as intended.

Automatic Reclosing

Where the installation includes an automatic reclosing relay, or a protection relay performing that function, we configure it and verify that the system returns to service under suitable conditions with minimum loss of supply after a fault.

We check every parameter: first trip time, reclosing cycles, delayed closing times and final lockout scenarios, confirming at each stage that the relay operates in step with the rest of the system.

Commissioning and Reporting

When testing and configuration are complete, we confirm correct system operation and close out the work. The activities carried out and the test results are delivered as a detailed report — a reference point for monitoring system performance and planning periodic maintenance.

To discuss protection engineering for your installation, contact us at info@varsenerji.com.