ORCHESTRATED ACTIVE FAULT MANAGEMENT FOR OFFSHORE WIND HIGH VOLTAGE DC GRIDS

Faults in power electronic devices dominated offshore power grids may cause severe problems, e.g. blocking of inverters and instability issues, in consideration of inverters' limited overloading capability. An orchestrated active fault management (OAFM) method is devised to manage offshore wind HVDC grids' performance under grid faults. OAFM aims to 1) avoid blocking of HVDC converters by minimizing fault current contributions from offshore wind farms, 2) minimize the power fluctuation of offshore wind farm inverters and 3) provide a fast and orchestrated frequency response to reduce frequency deviations and suppress possible frequency instability issues. OAFM is formulated as a multi-objective optimization problem to incorporate customized fault management objectives and constraints in a flexible manner. Experimental studies are performed on an extended CIGRE HVDC grid system to validate the effectiveness and efficacy of OAFM. Testing results show that OAFM works effectively in real-time to reduce fault current contributions from offshore wind farms and enhance system performance.