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Automatic generation control is extensively used to regulate power plants in a modern area of the power system network. In this paper, automatic generation and frequency control in interconnected power system is presented. A multisource such as thermal, hydro, and gas based power plant is considered in this study, which is carried out by incorporating non-linearity like generation rate constants, HVDC link, and the conventional PID controller design. Further, an optimal setting of the PID controller is performed by employing evolutionary and metaheuristic algorithm-based approach such as differential evolution and firefly algorithm, respectively. The robustness of the proposed controllers is assessed based on comparative analyses to regulate the interconnected power network's frequency profile under different loading conditions. The stability analysis is performed using the Eigen and Nyquist plots to assess the proposed controllers' efficacy. Besides, frequency control study is augmented with comparative assessment through various performance indices such as settling time, peak overshoot and undershoots under different operating conditions. Finally, the proposed control scheme, in the interconnected power system, is validated through a real-time digital simulation platform, i.e., OPAL-RT 5142. The comparison of simulation and real-time results demonstrate the effectiveness of the FA-optimized PID controller in comparison to that of De-optimised PID controller.

An adaptive fractional fuzzy sliding mode controller (AFFSMC) based power system stabilizer (PSS) is proposed for damping out low‐frequency oscillations in single machine infinite bus and multimachine power systems under various operational contingencies. The proposed stabilizer is a combination of adaptive fuzzy control with a fractional order proportional integral derivative controller and sliding mode controller. A fractional sliding surface is adopted which enables the system to remain in the proposed robust sliding surface stably to eliminate the effects of chattering at any initial conditions. In addition, fractional adaptive rules based on fuzzy sets were used for optimal selection of parameters of the controller. Here, the stability issue is addressed through Lyapunov synthesis. Speed deviation and acceleration are considered as input signals to the proposed controller. A comparative analysis of performance indices such as settling time, maximum peak overshoot is presented to demonstrate the advantages of the proposed approach. In addition, stability analysis using Eigen value, integral time absolute error and shape of demerit were also presented to augment the stability study. The simulation results confirm that the proposed AFFSMC‐PSS shows superior robust damping performance as compared to other approaches.

Regorafenib has been approved among the treatment options for patients with advanced stage colorectal cancer (CRC), hepatocellular carcinoma (HCC), and gastrointestinal stromal tumors (GIST). In this study, we aim to report the real-life experience of the safety and tolerability regorafenib in our institution. We conducted a retrospective chart review of 43 patients who received regorafenib in Kuwait Cancer Control Center (KCCC) from 2016 to the end of 2019. Data collected include diagnosis, patient demographics, performance status, number of previous lines of treatment, number of treatment cycles, side effects, best-tolerated dose, and treatment discontinuation due to intolerability. Univariate analysis with Pearson chi-square test were conducted to study co-relation between discontinuation rates and several factors. We had available data for 43 patients (23 males and 20 females). Of the patients, 83.7% had an ECOG performance status of 0 or 1. Seventy-three percent were diagnosed with metastatic CRC, 21% were diagnosed with HCC and 6% were diagnosed with GIST tumors. Half of the patients received 3 lines or more of treatment prior to regorafenib. The median number of cycles received was 3.7 with 11.6% of patients still on active treatment at the time of analysis. The most reported grade 3 and above side effects included rash (41.9%), fatigue (39.6 %), hypertension (25.6%), mucositis (21.9%), hand-foot syndrome (2.3%), and hyperbilirubinemia (4.6%). The best-tolerated dose was 80 mg and that was achieved in 44.2% of patients. The recommended dose of 160 mg could only be achieved in 20.9% of patients. The treatment was discontinued because of intolerability in 25.6% of patients. The discontinuation rates in those with ages 60 years and above versus below 60 years were 91% and 68%, respectively. In our cohort, the best-tolerated dose of regorafenib was 80 mg. Toxicity and intolerability of regorafenib lead to treatment discontinuation in nearly a quarter of patients. Patient age may influence tolerance and adherence to regorafenib.

Background: Early detection of pancreatic adenocarcinomas is essential for improving survival. In this regard, endoscopic ultrasound-guided fine-needle aspiration cytology (EUS-FNAC) has established itself as the method of choice for its ability to target lesions smaller than those which could be targeted by the traditional imaging methods like transabdominal ultrasound. Identifying these tumors correctly on FNA may be challenging because pancreatic adenocarcinomas may show a wide range of morphological features and the presence of contaminants from the gastrointestinal tract may show up as potential pitfalls. This study presents detailed cytomorphological analyses of 59 cases reported as pancreatic adenocarcinomas on smears and cell blocks. The clinical and histopathology follow-up data wherever available have also been presented. Materials and Methods: EUS-FNAC smears and cell blocks from cases reported as pancreatic adenocarcinomas were retrospectively evaluated with individual assessments of a range of features related to cellularity, cellular arrangement, cytoplasmic qualities, and nuclear features. Aspirates from peripancreatic lymph nodes, histopathology sections, and clinical records were reviewed wherever available. Results: Nonneoplastic cells like pancreatic ductal cells and acinar cells, duodenal, and gastric epithelia were detected along with neoplastic cells showing a wide range of variations in different cytomorphological characters. Often, a mixture of features was noted in the same case. Cell block preparations served as useful adjuncts since they made it possible to render unequivocal diagnoses of malignancies in cases where smears were hypocellular. Conclusion: The study creates a useful knowledge base of cytomorphological features of pancreatic adenocarcinomas.

Power quality (PQ) issues are significant in inverter-fed distributed generation system with non-linear loads which degrades the performance of the consumer equipments and the power system itself. Therefore, this work presents an improved photovoltaic (PV) coupled hybrid filter for the improvement in PQ in an active distribution system. A shunt hybrid active filter (SHAF) integrated with PV is designed with the help of an advanced signal processing approach called dual tree-complex wavelet transform (DT-CWT) for extracting the frequency information in the voltage and current due to the PQ disturbances. For calculating the reference current and switching signals, zero attracting least mean square (ZA-LMS) is considered in the hybrid filter and adaptive perturb and observe-fuzzy algorithm is proposed for maximum power point tracking in PV system to improve the performance under different operating conditions. The system model using the proposed technique is developed in MATLAB/Simulink and real-time experimental set up using two different controllers, i.e. the conventional proportional-integral (PI) and fuzzy-PI controllers. The results on comparison illustrates better performance of the proposed ZA-LMS and DT-CWT with fuzzy-PI based SHAF technique for PQ improvements with respect to that of LMS/normalised LMS with PI/fuzzy-PI based SHAF under different operating scenarios.

Three phase shunt active power filter (SAPF) using multilevel inverter (MLI) is implemented in this paper for a grid integrated solar photovoltaic (PV) system for eliminating the harmonics. The obj...

A novel switching pulse generation methodology based on adaptive fuzzy hysteresis current controlled hybrid shunt active power filter (A-F-HCC-HSAPF) is presented in this paper for compensating reactive power and harmonics in distribution network. The harmonic problems are mainly evolved because of extensive use of nonlinear loads in industry and domestic sectors. There are some adverse effects of harmonics such as: malfunctioning of sensitive equipment, resonance issues, conductors heating, power losses and reduced efficiency in distribution system. To mitigate harmonics issues passive, filters are used but when the harmonic component increases the design of passive filters is complex and becomes bulky. With the advancement in power electronic, the active power filter has been designed. Generally, the rating of the active filter is very high for some applications; hence hybrid shunt active power filter (HSAPF) is proposed by low-rated shunt active power filter (SAPF) and low-cost shunt passive filter. Proportional-integral or fuzzy logic controller is used to estimate the reference current and to regulate the dc capacitor voltage. To generate the switching pulse for the voltage source inverter of the SAPF, a novel adaptive fuzzy hysteresis current controller (A-F-HCC) is adopted. The performance of the proposed A-F-HCC-HSAPF is investigated during steady-state and transient conditions using MATLAB/Simulink and real-time environments.

This paper examines whether the fiscal deficit limit of 3% as prescribed by the FRBMA is justified keeping in mind the increasing spending requirement and economic growth of Indian states? The study uses a panel data framework of taking sixteen non-special category states of India for the period over 2001–2002 to 2016–2017. This paper is the first of its kind that uses a threshold regression model due to Khan and Senhadji (IMF Staff Papers 48(1):1–21, 2001) to find the threshold level of fiscal deficit. The empirical findings show that the threshold level of fiscal deficit in sixteen states taken together is found to be 3%, which is in the line of prescribed limit of FRBM act. But at disaggregated level, it is observed that in middle- and low-income states the threshold level of fiscal deficit is 3.9% and 3.5%, respectively. This suggests that states can go for some additional percent of fiscal deficit above the limit prescribed by FRBMA. Therefore, the fiscal deficit limit of 3% needs to be revisited to give more fiscal room to the Indian states.

Cyber-physical attacks and parameter uncertainties are becoming a compelling issue on load frequency control, directly affecting the resilience (i.e., reliability plus security) of the microgrid and multi-microgrid systems enabled by internet of things and the fifth generation communication system. A resilient system aims to endure and quickly restore a system’s transients during extreme events. Therefore, it is critically important to have a resilient system to evade the total system failure or blackout in order to make them attack-resilient. With this objective, this paper presents a resilience-based frequency regulation scheme in a microgrid under different operating conditions, such as, step and random change in load and different wind speed patterns. Furthermore, a cyber-attack model is considered in the problem formulation to make the system robust against external attacks. To protect against the cyber-attack and parameter uncertainties in the system, different control schemes are employed, and their robustness characteristics are compared through various performance indices. Besides, the proposed control schemes are validated through a real-time software synchronisation environment, i.e., OPAL-RT. As noted, the proposed type-2 fuzzy proportional-integral-derivative based controller provides the most significant improvement in the dynamic performance for frequency regulation compared to that of the others under the cyber-attack and uncertainties.

This paper evaluates the revenue effort of Indian states during the 13th and 14th Finance Commission periods and estimates the impact of central transfers recommended by the Finance Commission on the relative revenue effort of states. Using panel data the study finds that Bihar, Uttar Pradesh, Madhya Pradesh, Assam and Kerala are the top five states with the greatest relative revenue effort. Further, the impact of central transfers on revenue effort was found to be negative, suggesting that greater devolution encourages laxity in the state's tax collection efficiency by providing perverse incentives.

There is a growing evidence showing that there are geographic differences in hepatocellular carcinoma (HCC). Little is known about the characteristics of hepatocellular carcinoma in the Arabian Peninsula. The present study examines the presentation and outcomes of HCC in a single institution. A retrospective chart review of patients presented with advanced-stage HCC to Kuwait Cancer Control Center (KCCC) between 2008 and 2018 was conducted. Data collected included patients demographics, HCC risk factors, performance status, Child-Pugh score, pick up of sorafenib, and survival. About 111 cases were analyzed. The mean age of the cohort was 61.8 ± 11.4 years and 94 patients (84.7%) were males. HCV and diabetes were the most common risk factors for HCC and presented in 60 patients (54.1%) and 45 patients (40.5%), respectively. About 78 (70.3%) patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0–1 at presentation. Only 29 (26.1%) patients presented with Child-Pugh class A, while 42 (40.4%) patients received sorafenib. The median overall survival was only 3 months. In our cohort, HCV and diabetes were the main risk factors for HCC. The majority of patients was not amenable to sorafenib treatment and carries a very poor prognosis.

This article focuses on the implementation of a hybrid firefly algorithm-particle swarm optimization (FAPSO) scheme for optimizing the parameters of an interval type-2 fractional order fuzzy proportional integral derivative (IT2FOFPID)-based power system stabilizer (PSS) to minimize the low-frequency oscillations in a power system. Here, the IT2FOFPID-based PSS is designed by considering speed deviation and acceleration as input signals. In this article, a single machine infinite bus system and the New England 10 machine 39-bus power system are used for testing and comparing the approaches. Stability studies are also performed using OPAL-RT's OP5600, a real-time digital simulator. The comparative studies demonstrate that the hybrid FAPSO optimized IT2FOFPID-PSS provides better damping and stability performance when compared with the PSSs based on the FA/PSO/ hybrid genetic algorithm and bacterial foraging optimization and hybrid differential evolution and pattern search optimized IT2FOFPID approaches under various operating scenarios.

This paper examines the link between economic growth and fiscal deficit in India for the periods between 1970–71 to 2016–17 and 1970–71 to 2003–04. The study uses an autoregressive distributed lag ...

Magnetic materials have become more and more user friendly in recent days particularly in an electronic based infrastructure. The study proposes a direct drive permanent magnet based Synchronous Generator as Tidal turbine in a hybrid tidal wave energy conversion system (TWECS) and discusses its performance for better stability. The objective of the study is to analyse the role of permanent magnet based generator in TWECS for overall improvement of stability through reactive power management. The isolated TWECS becomes unstable either by random load variations or by non uniform wind and tidal power inputs. Consequently the overall stability of the TWECS is brought to stable and normal stage by the control of reactive power with the inclusion of the custom power based devices. In addition to the effects of permanent magnet in case of DDPMSG for improving the overall system stability, optimisation tools like PSO, GSA and PSOGSA are added for further improvement in system performance.

In this paper, a multilevel inverter based shunt hybrid active filter is used, which is composed of passive filter and shunt active filter, used for enhancing the quality of power, by reducing the total harmonic distortions below 5% as per IEEE-519 standard and managing the reactive power as well as correcting the power factor. The objective of this paper is to advance the power quality by reducing the harmonic distortions in the distribution line, which are affected because of utilising non-linear loads across the load end. For reference current generation and for controlling the switching signal, conventionally PI controller was used with different reference signal detection techniques. But with the evolution of different intelligence approaches, made more advantageous than the PI controller. In this paper, two artificial intelligence methods, i.e, artificial neural network and adaptive neuro-fuzzy interference system (ANFIS) are applied. Comparison of the results of the proposed methods is analysed using MATLAB/ SIMULINK tool. For reference current generation, synchronous reference frame theory is used and hysteresis current control technique is employed for generating the gating signal.

In this paper, a three-phase series hybrid active filter (SEHAF) interconnected with photovoltaic (PV) system and dc–dc boost converter is proposed to minimize sag, swell, and harmonics caused due to nonlinear power electronic loads. The SEHAF consists of a voltage source inverter (VSI) with a capacitor connected across it to provide consistency in managing and compensating the reactive power. This minimizes the sag, swell, and harmonics present in the source and load voltages. With the integration of PV, the voltage across the dc-link capacitor of VSI is controlled effectively, which helps in better compensation. Reference current generation is done using the proposed robust extended complex Kalman filter (RECKF) technique. The performance of the PV-integrated-HAF is analyzed using a synchronous reference frame with proportional-integral (PI) as well as fuzzy logic controller (FLC) and is compared with the proposed RECKF technique. The PV-integrated hybrid power system is developed using MATLAB/SIMULINK. Further, real-time digital simulation using OPAL-RT OP5142 is also carried out to support the simulation results. It is observed that the proposed control scheme provides better harmonic compensation compared to conventional PI and FLC.

This work describes a number of soft-computing based solar forecasting techniques that facilitate the modelling of newly installed solar cell. The solar cell model is developed and validated against measured data. Prediction of solar radiation of a particular location depends upon number of inputs. So selection of most relevant input parameters is an important task for getting good predictions. The input parameters of the model used in this paper are sunshine duration, temperature, humidity where as the clearness index is considered as an output parameter. The magnitude of active current associated with PV inverter has been finalised by the solar based irradiation. The reactive current associated with the PV based inverter is controlled through the optimised solar radiation.