engleski

Analysis of Croatian Power System Dynamic Response In Case Of Switching The 400 kV Line Tumbri – Heviz In Real System

The paper presents field test and simulation results of the dynamic behaviour of the Croatian power system following switching off and on of the 400 kV line Tumbri - Héviz. This interconnection line between Croatia and Hungary has major impact to the operation of the Croatian power system. Power flow on it is usually 500 to 1000 MW in the north-east to south-west direction. Results of preliminary dynamic stability studies of Croatian power systems pointed at potential risk of inadequate stability margins, hence it was felt necessary to verify the simulation results by comparison with field test results. Suitable tests were performed when the above mentioned 400 kV line had been switched off for maintenance purposes. Four test teams were engaged: three of them at the major 400 kV substations in Croatian power system and one at the National Dispatching Center in Zagreb from where the whole operation was coordinated. Active power flows on selected transmission lines and power frequency were recorded by suitable digital equipment. Steady state of the Croatian and neighbouring power systems immediately before and after the line switching was captured in close collaboration with operators in regional dispatching centers and in neighbouring countries. Prony analysis of the test results yielded characteristic interarea modes of oscillations observable in the Croatian power system. In comparison with simulation results the measured dynamic responses are better damped which calls for further refinement of simulation models.

electric power system; electromechanical transients; measurement; Prony analysis; simulation

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