Power swing testing
The realistic power system quantities generated by NetSim are essential for successfully testing advanced power swing blocking functions in modern relays. In this context, simple impedance ramps or sequences of impedance states are often not sufficiently realistic to test the function correctly. Asynchronous power swings can also be generated with multiple pole slips for effectively testing Out-of-Step (OST) functions. The synchronous power swing test case simulates a transient oscillation that returns to a stable state. In the impedance view the apparent impedance trajectory can be shown together with the relay distance zones.
Three terminal line
Due to their cost benefits, tapped lines are being installed more frequently. Depending on the individual segment properties (e.g. cable tap on overhead line) or topographical layout (e.g. a tap is located close to one end) distance protection may have serious zone reach problems with this configuration. The three-terminal line test case included in NetSim is ideal for investigating fault conditions on tapped lines. Finding optimized protection settings for this difficult case is made much simpler.
End-to-end testing application
Dynamic End-to-End testing of the complete protection scheme (e.g. for transmission lines) offers many advantages but is also subject to some limitations due to its high level of complexity, time consuming preparation, and the time available for the execution of the test. NetSim helps to overcome these through its intuitive operation, defined models, and instant calculation of the different test cases.
Unlike other commonly used power system analysis software, NetSim is intended mainly for the needs of the protection engineer. It provides a direct output of test signals without the need for intermediate transient file handling steps. The support of the CMGPS and CMIRIG-B units in NetSim allows the synchronization of test sets at each end of the line with precise test initiation and timing. In addition, it is possible to integrate a sequence of test cases into the OMICRON Control Center and execute the whole sequence with just one mouse click.
