| Abstract: | Maloperation of conventional relays is becoming prevalent due to ever increase in complexity of conventional
power grids. They are dominant during power system contingencies like power swing, load encroachment, voltage
instability, unbalanced loading, etc. In these situations, adaptive supervised wide-area backup protection (ASWABP)
plays a major role in enhancing the power system reliability. A balance between security and dependability of
protection is essential to maintain the reliability. This paper proposes multi-phasor measurement units (MPMU)
based ASWABP scheme that can function effectively during faults besides power system contingencies. MPMU is an
extended version of Phasor Measurement Unit (PMU). It is an intelligent electronic device which estimates the
synchronized predominant harmonic phasors (100Hz and 150Hz) along with the fundamental phasors (50Hz) of
three phase voltages and currents with high precision. The proposed ASWABP scheme can detect the fault, identify
the parent bus, determine the faulty branch and classify the faults using MPMU measurements at System Protection
Center (SPC). Based on these MPMU measurements (received at phasor data concentrator (PDC) at SPC) the
appropriate relays will be supervised to enhance the overall reliability of the power grid. Numerous case studies are
conducted on WSCC-9 bus and IEEE-14 bus systems to illustrate the security and dependability attributes of
proposed ASWABP scheme in MATLAB/Simulink environment. Also, comparative studies are performed with the
existing conventional distance protection (Mho relays) for corroborating the superiority of the proposed scheme
regarding security and dependability. Comparative studies have shown that the proposed scheme can be used as
adaptive supervised wide-area backup protection of conventional distance protection |
