HVDC fault tolerant converter for renewable energy source grid

Renewable energy source network need HVDC transmission system since it has an ability to transmit large power over a long distance with less loss and without any need of synchronization. This paper deals with the operation of hybrid multilevel VSC with AC side cascaded H-bridge cells which will have ability to tolerate faults, current limiting capability during DC fault, large real and reactive power control capability and black start capability in an HVDC bipolar network. The paper also analyses the performance of the system under network alterations such as AC and DC faults using a Fuzzy controller along with PI controllers. The simulation was done using MATLAB/ SIMULINK.