An Extended Model Predictive-Sliding Mode Control for Three-Level AC/DC Power Converters

Abstract- In the proposed approach, an Extended Model Predictive Sliding Mode Controller (EMPSMC) was designed to control three-level AC / DC power converters for better dynamic performance and better achievement. The traditional proportional integration (PI) controller is used in the model predictive PI controller (MPPIC) technique to generate active power reference. However, this technique results in a significant overshoot/undershirt and steady-state error. Instead of PI, sliding mode control (SMC) is used to address these shortcomings. The performance of EMPSMC and MPPIC is compared and analyzed without interruption. The results show that the introduction of SMC reduces the time lag of the system and reduces overshoot. The simulation results validate the performance of the designed model.

Ecological Evaluation of Plant Resources and Vegetatation Pattern of Jelar Valley, Dir Ipper, Pakistan

The present study aimed to explore ecological evaluation of plant resources and vegetation pattern of Jelar valley, Dir Upper during 2014-2017. Floristic list of the study area revealed that flora of Jelar valley is diverse and comprised of 250 species belonging to 177 genera and 77 families. The dominant families in term of species richness were Asteraceae and Lamiaceae, (each with 20 species, 8%), Rosaceae (19 species, 7.6%) and Papilionaceae (16 species, 6.4%), while the dominant genera were Polygonum and Rosa (each with 5 species). Due to harsh climatic conditions in winter, maximum numbers of species were found in summer and autumn. Biological spectrum showed that therophytes (101 species, 40.4%) were dominant followed by hemicryptophytes (43 species, 17.2%), while microphylls (32%) and nanophylls (30%) respectively dominating the leaf spectrum.The quantitative analysis of trees species in six study sites were subjected to Pc-Ord for cluster analysis, could establish four vegetation groups. Ailanthus altissima-Quercus incana community was distributed in Gumbad and Gul Dherai at 1967±130 (Mean± SE) m altitude with 20.1±2.3 slope angle. This group was more diverse (27 trees) as compared to others. Pinus wallichiana-Quercus incana community was distributed in Sore Pao at 1808 m altitude with 20.1±2.3 slope angle. This community consisted at total of 14 trees species. Pinus wallichiana- Prunus armeniaca community with fewer numbers of species recognized in Shao at 2058.6 m mean altitude with 15.6 slope angle. Similarly, Pinus wallichiana-Ailanthus altissima association was found in Tangi Awar and Danda at 2070.8 m altitude with 12.7 slope angle. Wards cluster and NMS ordination of 88 understory vegetation from six different zones constituted a total of four groups as; Sarcococca saligna-Isodon rugosus community at Gumbad, Wikstroemia canescens-Berberis lycium community at Sore Pao and Gul Dherai, Berberis lycium-Indigofera heterantha community at Shao and Danda and Berberis lycium-Indigofera heterantha community at Tangai Awar. NMS and PCA ordination were used to explore the relation of edaphic and environmental variables with trees species. Correlation of NMS ordination axis 1, 2 revealed that the NMS ordination axis 1 was only significantly correlated with nitrogen (P<0.05) while axis 2 was significantly correlated with altitude (P<0.001), organic matter % (P<0.05), Pb (mg/kg) (r= 0.83695, P<0.05) and Ca (mg/kg) (r= 0.947312, P<0.01) while PCA ordination axis 2 was significantly correlated with altitude and organic matterand axis 1 with slope angle. The relationship of NMS ordination axis with environmental variable associated with understory vegetation revealed that altitude and organic matter were found in significant correlation (r= 0.997, P<0.001) with axis 1 and lime % with axis 2. Lead (r= 0.752, P<0.05) and Ca (r= 0.947, P<0.01) with Axis 1. NMS ordination axis 2 was significantly correlated with nitrogen (r= 0.787, P<0.05) and Cu (r= 0.939, P<0.01). The soil was generally loamy sand, acidic in nature and slightly calcareous. Contents of organic matter ranged from 0.69% to 1.932%. The nitrogen contents were 0.966 to 0.0345 (mg/kg) while potassium 110 to 240 (mg/kg) and Cu 0.245 to 0.327 (mg/kg). Similarly, Zn 0.138 to 0.573 (mg/kg), Fe 0.879 to1.305 (mg/kg), Mn 1.885 to 6.179 (mg/kg) and Pb 1.0765 to 1.88 (mg/kg) were recorded. The concentration of Ca, Mg and sodium ranged respectively from 9.126 to 9.948, 2.2835 to 2.4545 and 16.9 to 19.45 (mg/kg). ANOVA showed significant variation at P<0.001 for all physicochemical parameters except soil texture. The palatability results revealed of the 250 plants species 55 (22%) were non-palatable and 195 (78%) were palatable which shows the grazing pressure. Among them 99 (39.6%) species were highly palatable, 51 (20.4%) species less palatable and 45 (18%) species rarely palatable. Livestock preferences showed that goats and sheep preferred 172 species while buffalo 71 species. Based on part used 98 (49%) species were consumed as whole plants and in 89 (44.55%) species only leaves were utilized, while in 13 (6.5%) species inflorescence was consumed by livestock. Similarly, some 116 (59.5%) species were found to be grazed in fresh condition, 2 species when it is dried and 77 (39.5%) species both in fresh and dried condition.In addition, the elemental composition of Impatiens bicolor, Myrsine africana, Themeda anathera, Sarcococca saligna and Quercus dilatata were evaluated at pre-reproductive and postreproductive stages. The results revealved that Ca, Zn and Fe concentration were found high at pre-reproductive in all the selected species, while Mg contents were noted higher only in Sarcococca saligna and Myrsine africana at pre-reproductive stage. Phosphorus contents were found higher at pre-reproductive stage in Themeda anathera and Quercus dilatata, while Cu concentration was high at pre-reproductive stage only in Sarcococca saligna. Similarly K, Mn and Pb contents were found higher at post-reproductive stage in all the selected plants, while P were higher at post-reproductive stages only in Impatiens bicolor, Myrsine africana and Sarcococca saligna. Copper concentration was maximum at post-reproductive stages in all the species except Sarcococca saligna which was more at pre-reproductive stage. Magnesium concentration was found more only in Impatiens bicolor, Themeda anathera and Quercus dilatata at post-reproductive stages. Ethnomedicinal study of the plants depicted that almost all parts of plants (21.7%), followed by leaves only (25.3%) were used in curing diseases, while the common mode of administration was usually decoction. Most of these species were multipurpose in their medicinal uses. Based on FIV the best represented used family was Lamiaceae (91.11), followed by Asteraceae, while the highest RFC was recorded for Mentha longifolia (0.266) followed by Olea ferruginea (0.259). The conservation status of medicinal flora revealed that Melia azedarach was found endanger, 35 (42%) species were rare, 15 (18%) species infrequent and 32 (39%) species were recorded as vulnerable in the area. Following the IUCN criteria for conservation none of the population was declared in the dominant category.