Power systems are usually exposed to numerous disturbances that can have an adverse effect on system
operation. Insufficient generation could lead to frequency declination and subsequently system collapse
in the absence of immediate control action. Frequency Load Shedding (UFLS) is a technique commonly
applied to overcome overloading and restore the system frequency. This paper presents an adaptive load
shedding approach to determine the best location with minimum amount of load to be shed. Load Ranking
Fuzzy Logic (LRFL) is used to rank the load based on their sensitivity and stability index. In order to
achieve this, the proposed strategy is verified using 11 kV Malaysian distributed network consisting of
different type of loads connected with single and multiple Distribution Generator (DG). The simulation
results show that the proposed strategy successfully stabilizes the system’s frequency.
Polyethyleneglycol bound sulfonic acid (PEG-OSO₃H), a chlorosulphonic acid-modified polyethylene glycol was successfully used as an efficient and eco-friendly polymeric catalyst in the synthesis of 14-aryl/heteroaryl-14H-dibenzo[a,j]xanthenes obtained from the reaction of 2-naphthol and carbonyl compounds under solvent-free conditions with short reaction times and excellent yields. The biological properties of these synthesized title compounds revealed that compounds 3b, 3c, 3f and 3i showed highly significant anti-viral activity against tobacco mosaic virus.
This paper proposes an approach to accurately estimate the impedance value of a high impedance fault (HIF) and the distance from its fault location for a distribution system. Based on the three-phase voltage and current waveforms which are monitored through a single measurement in the network, several features are extracted using discrete wavelet transform (DWT). The extracted features are then fed into the optimized artificial neural network (ANN) to estimate the HIF impedance and its distance. The particle swarm optimization (PSO) technique is employed to optimize the parameters of the ANN to enhance the performance of fault impedance and distance estimations. Based on the simulation results, the proposed method records encouraging results compared to other methods of similar complexity for both HIF impedance values and estimated distances.