Hardware implementation of a hybrid protection scheme for bipolar HVDC line

Implementation of a hybrid protection scheme for bipolar HVDC line with field-programmable gate array (FPGA) is described in this paper. The protection scheme amalgamates a traveling wave protection unit, a boundary protection unit and a lightning unit. Stationary wavelet transform (SWT) and its wavelet modulus maxima are used to remove noise and represent useful traveling wave signal. Boundary protection based on SWT is used jointly with traveling wave protection to distinguish internal faults from external faults. Lightning unit is used to distinguish non-fault transients and to identify the faulty pole. Xilinx XtremeDSP Development Kit-4 is employed for prototyping the relay, with coding done using Xilinx System Generator and AccelDSP.