Introduction  This paper explores multiple issues including the voltage application method, test voltage standard, test casing layout, and test item sequence for the handover test of the electrical primary equipment of the world's first 500 kV offshore booster station.

  Method  Based on the test conditions and requirements, a comparison and analysis of the test voltage values and the insulation strength of the equipment were conducted. According to the structural characteristics of GIS and cables, the method of jointly testing GIS and cables was used to apply voltage to the cables. Considering the spatial environment and maximum insulation distance of the offshore booster station, the 500 kV GIS withstand voltage test casing was arranged outside the booster station. By comparing the test voltage values of the test items for 500 kV and 66 kV distribution equipment, the test item sequence was arranged rationally.

  Result  The voltage application method for the withstand voltage test of the medium voltage winding of the main transformer, the voltage standard for the 66 kV GIS test, and the sequence of test items for cables and GIS equipment are determined. The handover tests of transformers, cables, and GIS are completed at the manufacturing base.

  Conclusion  The handover test method for the electrical primary equipment of the world's first 500 kV offshore booster station can be used to simplify the test preparation work and shorten the test period. The method demonstrates certain engineering application value and can be used as references for other offshore booster station projects.