Scheme Design and Test verification of Long-term Assessment for ±550kV DC GIS

DC GIS equipment can significantly reduce the construction area and maintenance costs of offshore converter platforms, which is the trend of future development. Therefore, it is necessary to conduct long-term live assessment to test the insulation reliability and operational stability of the equipment under actual operating conditions. At present, there is no official IEC DC GIS standard released internationally, and there is no standard long-term live assessment plan for DC GIS. Based on the completed assessment plans and draft IEC standards for DC GIS products both domestically and internationally, propose a high standard long-term live assessment plan that meets the operational requirements. Combined with ±550kV DC GIS, according the plan to Conduct long-term electrification test verification, and the results verified the feasibility of the testing plan and the stability of the product. At the same time, it provides reference for the long-term live assessment of other DC equipment.