894 / 2019-04-30 15:04:42

Performance on Investigation of Half-bridge MMC typed DC Chopper Design for Wind Farm Connected VSC-HVDC Project

DC chopper, half-bridged MMC, braking resistor, wind farm connected VSC-HVDC

This paper provides the design of DC chopper for a VSC-HVDC project consisting of half bridge MMC typed chopper valve and braking resistors. The modulation strategy developed would ensure that DC chopper can absorb any percentage of the energy from wind farm, even for the most severe operational condition. HVDC converter stations would be able to ride through any grid faults as long as the entire accumulated energy, which could not be fed into the grid due to grid faults, is less than the thermal capacity of the chopper. The HVDC system would be designed to temporarily reduce the active power in-feed into the onshore grid if the EPC1 signal is triggered, since the system automatic EPC1 function ensures a short-term active power reduction of the HVDC system by using the braking resistor (Chopper) in the DC circuit.