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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 presents a Hybrid Shunt Active Power Filter (HSAPF) optimized by hybrid Particle Swarm Optimization-Grey Wolf Optimization (PSO-GWO) and Fractional Order Proportional-Integral-Derivative Controller (FOPIDC) for reactive power and harmonic compensation under balance and unbalance loading conditions. Here, the parameters of FOPID controller are tuned by PSO-GWO technique to mitigate the harmonics. Comparing Passive with Active Filters, the former is tested to be bulky and design is complex and the later is not cost effective for high rating. Hence, a hybrid structure of shunt active and passive filter is designed using MATLAB/Simulink and in real time experimental set up. The compensation process for shunt active filter is different from predictable methods such as (p-q) or (id-iq) theory, in which only the source current is to be sensed. The performance of the proposed controller is tested under different operating conditions such as steady and transient states and indices like Total Harmonic Distortion (THD), Input Power Factor (IPF), Real Power (P) and Reactive Power (Q) are estimated and compared with that of other controllers. The parameters of FOPIDC and Conventional PID Controller (CPIDC) are optimized by the techniques such as PSO, GWO and hybrid PSO-GWO. The comparative simulation/experiment results reflect the better performance of PSO-GWO optimized FOPIDC based HSAPF with respect to PSO/GWO optimized FOPIDC/CPIDC based HSAPF under different operating conditions.

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.

Stability of a standalone hybrid power system (HPS) in a smart grid is always a challenging task. Further, the operational stability of the power system depends on the associated communication infrastructure. Therefore, it is always crucial to pick up a controller that can assure system's stability along with performance, despite disturbances like (load and input wind variations) with communication delays. Present study focuses on reactive power management and voltage stability issues of an isolated HPS. The stability aspects of HPS are improved through reactive power compensation, by custom power devices like static var compensator. The control aspects of SVC as well as the whole hybrid system are taken care by H∞ linear matrix inequalities approach. Further, H-infinity control, Lyapunov stability along with linear matrix inequalities techniques estimate the delay boundary of controllers. The iterative performance of the proportional–integral–derivative controllers, and robust H∞ damping controller of the HPS, are designed through LMI approach. Later experimental study of the HPS is done, with a prototype model in dSPACE real-time control environment. In this case, dSPACE 1104 is added for data acquisition and control. Adaptability and robustness of the proposed controllers are verified under fluctuating loads and uncertain wind power input.

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.

This paper presents wavelet transform, independent component based detection of the power quality disturbances in a microgrid. Wavelet transform (WT) is well known for its better time-frequency multi-resolution analysis because of selection of adaptive window size depending inversely with the frequency. This makes it suitable for identification of both stationary and non-stationary characteristics of the power quality disturbances. But, it is analyzed in the study that the detection capability of wavelet is degraded when the input voltage signal contains noise and completely fails when the noise level is increased to 25 dB. Of course, a wavelet-denoising technique is tested to improve the ability of wavelet transform under noisy conditions, but observed to increase the detection time. Hence, independent component analysis (ICA) is proposed for detection based on its property of finding the significant components which are statistically independent and non-Gaussian. In addition, the statistical features are extracted to formulate the input dataset for support vector machine (SVM) to classify different power quality disturbances like sag, swell, interruptions, harmonics, transients, and flickering. A comparative analysis is presented and it is observed from the study that ICA-SVM hybrid combination provides better classification accuracy as comparison to WT-SVM under different operating scenarios.

This work discusses the implementation of JAYA-DE algorithm with Static Var Compensator for optimum voltage control through Reactive Power compensation inside solar based hybrid power system.The stability aspect of isolated solar based hybrid power system is enhanced through compensation of the reactive power by optimized SVC and are further analyzed with different stability criterion. The dynamic performance of the new hybrid technique under intermittent wind power input and variable load show superiority over the conventional control methods.

In this work a photovoltaic (PV) and battery storage system (BSS) based microgrid (MG) integrated with shunt hybrid active filter (SHAF) is proposed for power quality (PQ) enhancement in three phase system. The proposed system is developed to reduce harmonics and manage the reactive power in the power system. For tracking the maximum power in the PV array, a novel self-tuned perturbs and observe (SPO) algorithm is employed. The SHAF employs a maximize M Kalman filter (MMKF) for reference current estimation and hysteresis current control (HCC) for switching signal generation. The proposed system is compared with the traditional Kalman Filter using MATLAB/Simulink tool.

Electrical power generation from solar PV has taken a significant position nowadays because of its availability and less or zero pollution. Integration of solar PV with grids in a resilient way and getting power out of it efficiently has now become a new challenge because of its life-span. This paper demonstrates a model in which a three-phase voltage source inverter is connected with Interleaved Soft Switching Boost Converter which incorporates distinct topologies to provide better efficiency because of decreasing value of current and voltage ripples in isolated grid conditions. The use of a specific approach in PWM and soft switching gives remarkable minimization in switching loss. The proposed strategy has been implemented in MATLAB Simulink platform by taking variable irradiances and loads at different power factors. The simulation results from the designed model provide a ground to establish the enhancement in efficiency as well as cost-effectiveness. The THD of load current is minimum and hence the inverter output.

This article proposes an adaptive neuro-fuzzy sliding mode control based power system stabilizer (ANFSMC-PSS) with an aim to minimize low frequency oscillations (LFOs) arising due to disturbances in the power system. The proposed ANFSMC-PSS is a combination of sliding mode control (SMC) and neuro fuzzy system (NFS) to enhance stability of power system. Here, stability is assured through Lyapunov criterion. The proposed ASMT2NF-PSS considers both local signal (speed deviation) and remote signal (accelerating power) provided by PMUs as input signals and its efficacy is investigated in both single machine infinite bus (SMIB) and multimachine power system (MMPS) under various disturbance conditions. The simulation results clearly shows that the proposed ANFSMC-PSS gives superior oscillation damping performance as compared to that of fuzzy sliding mode control based PSS (FSMC-PSS), sliding mode control based PSS (FSMC-PSS) and conventional lead-lag based PSS (CPSS) under different disturbance conditions.

Hepatocellular carcinoma (HCC) is an important cause of mortality from cancer. Data from the Arabian Gulf region indicates that liver cancer is the sixth most common cancer in the Gulf Cooperation Council (GCC) states, representing 5.2% of all cancers diagnosed between 1997 and 2007. There is increasing knowledge about geographic variations for hepatocellular carcinoma (HCC) incidence. Not much is recognized about the pattern of hepatocellular carcinoma in the Arabian Peninsula. Few studies addressed epidemiology and risk factors of hepatocellular carcinoma in this region with no previous studies investigating this malignancy in Kuwait. This chapter reports the presentation and consequences of HCC in Kuwait. Throughout different chapter sections, we highlighted different etiological factors for HCC incidence with special focus on prevalence of these risk factors in Kuwait. We compared universal data with our study on HCC incidence in Kuwait. This chapter also highlights different diagnostic tools for HCC diagnosis in Kuwait and different management modalities used in our cancer center. It also shows advanced stage for HCC at time of diagnosis.

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.

Medullary thyroid cancers (MTC) constitute about 5% of all thyroid cancers. The 10-year overall survival (OS) rate of patients with localized disease in thyroid for this pathology is 80% to 90% which is comparable with differentiated thyroid cancers, figures drop to 75% for cases with nodal metastases. Only 20% of patients with distant metastases at diagnosis survive for 10 years. In metastatic disease there are variations with smoldering less active disease to progressive active disease. Surgery is cornerstone of the management with total thyroidectomy and nodal dissection as main treatment. Adjuvant treatment with radiotherapy is case selective, varies from case to case. The management of residual, recurrent disease is possible re-surgery with external beam radiation therapy. The development of targeted therapy has brought in a major advantage in management of metastatic disease. Two drugs -vandetanib and cabozantinib- have been approved for use in metastatic MTC. The optimum management in this group of patients is a challenge and long-term use of TKI needs to be balanced with monitoring side effects of TKI and dose adjustments of TKI.A retrospective review of cases with diagnosis of medullary thyroid cancers treated or registered at Kuwait Cancer Control Center was conducted. The data of patients registered between 1987 till 2017 was analyzed. The data was collected and analyzed using SPSS (version 20) software program. For analysis we considered date of surgery as the date of diagnosis. Final state of disease along with emphasis on prognostic factors was correlated with Kaplan Meyer survival curves.There were total 31 cases out of which 15(48.4%) were male and 16(51.6%) females. The median age at presentation was 51.6 years (range-28years-77years). MEN syndrome was diagnosed in 6(19.4%) patients. Staging revealed Stage I - 7/31 (22.58%), Stage II-3/31(9.67%), Stage III-7/31(22.58%), Stage IVA (nonmetastatic) -12/31 (38.70%), Stage IVC (metastatic) - 2/31 (6.45%). Total thyroidectomy and central compartment neck dissection was optimum surgery (29%). Total thyroidectomy with central compartment neck dissection and unilateral neck dissection was done in 38.7% patients, comprehensive neck dissection and total thyroidectomy was done in 32.2% patients. External beam radiotherapy (EBRT) with conformal or IMRT technique was used in 13 out of 31 patients. One patient was treated for bony metastasis with palliative intent. Four patients were treated by TKI for metastatic disease or at progression. Median follow up was 79 months. Median overall survival was 93 months. Median progression free survival irrespective of stage was 62 months. At the end of 5 years 61% patients were alive irrespective of stage of disease. Due to the small sample size and natural history of advanced MTC the observed p-value for several pathological variables in relation with survival was not significant.Stage I and stage II cases of our study did well and were all alive and disease free till our last follow up. EBRT in our cohort of patient did not revealed any added benefits in survival. The use of TKI in metastatic disease was associated with many issues including availability of drug. Elevated serum calcitonin and CEA levels in absence of measurable disease should be dealt cautiously.

A comprehensive review on stability analysis in multimachine power system is presented in this study. The increasing demand of power has led to the expansion of power system and complexity in design as well as operation. This threatens to deteriorate the stability and reliability in the power network. However, with the advances in semiconductor and power electronic control technology, various flexible AC transmission systems (FACTS) are designed to enhance the power system stability. Different power system configurations with the incorporation of conventional and distributed generations (DGs) are proposed whose stability is being tested in the presence of the FACTS controllers. The optimal damping of power system oscillations under transient operating conditions are studied in presence of HVAC and HVDC links with conventional as well as DG systems and energy storage options like battery, supercapacitors and so on. Different control approaches such as classical control, robust control, wide-area control along with soft computing approaches like neural networks, fuzzy logic control, adaptive neuro-fuzzy inference system, genetic algorithm, particle swarm optimisation and so on are broadly discussed. A comparative analysis of different methodologies is presented to establish a quick survey of the proposed solutions for stability enhancement.

In this paper, the simulation results of static var compensator (SVC) for improvement of transient stability in a photo voltaic (PV) system integrated power system are presented. A Proportional Integral Derivative (PID) controller was also incorporated with SVC for contributing necessary damping in case of various disturbance conditions. Here, the dynamic stability of the PV based power system was studied in single machine infinite bus (SMIB) and power system. SVC is integrated with the above PV based power system for damping low frequency oscillations produced due to disturbances in the power system. Further a novel soft computing based approach called quasi-oppositional differential search algorithm (QODSA) was for designing an optimal SVC-PID based damping controller. Initially DSA was applied for optimizing the gains of the controller and finally quasi oppositional learning was incorporated to DSA for obtaining the optimal parameters of SVC-PID controller and also for enhancing the convergence speed. The effectiveness of the proposed technique was also tested with particle swarm optimization (PSO) technique. Transient stability analysis for conventional PID controller, PSO based PID controller, DSA based PID controller and QDSA based PID controller was done analytically as well as quantitatively. It can be observed from the simulation results that the proposed QDSA based PID controller outperforms over other techniques in improving power system stability and also damping low frequency oscillations.

Solar photo voltaic cells are increasingly finding application in either grid connected power system or Standalone solar power system. PV cells are being used in combination with other renewable energy sources to form a distributed generation based hybrid power system. Though solar cell ideally contributes lot in hybrid power generation, uncertainty in solar insolation creates disturbances and power quality problem. Variable solar insolation, uncertain weather condition affects the Photo voltaic cell causing voltage disturbance, harmonics and other quality problems. Because of this Efficiency of solar cell is highly affected though harmonics remains low in comparison to conventional AC power supply in both load and source side. This paper analyses a practical set up of solar system in lab VIEW platform and investigates the effect of variable solar radiation on it.

Modified wavelet called wavelet packet transform (WPT) based approach is proposed in this paper for the detection of different disturbances occurring due to faults in grid-connected solar photovoltaic (SPV) power system. The detection performance of WPT is compared with that of wavelet transform under different operating scenarios. Further, performance indices such as energy and standard deviation (SD) are calculated to identify the faults from normal operating conditions. The qualitative and quantitative study suggests better detection performance of WPT over WT under different operating scenarios.

The modern power systems have now prompted the practice of power electronics-based converters for power conversion purposes, which has emerged a solid-state device named as solid-state transformer (SST). It provides the isolation between low/medium-voltage ports with a high-frequency transformer (HFT), and in addition, it facilitates controlling the active and reactive power automatically through power converters. With this objective, the SST is projected as an essential device for smart/microgrids, particularly in multi-microgrid systems, to enhance modern distribution systems' resiliency. This study explores how it is beneficial to the distribution systems in regards to the reduction of size, controllability, reliability, resiliency, and end-use applications. Moreover, the different component types and broad applications have also been discussed pertaining to their characteristics. Lastly, the conclusion gives a brief summary, and the possible direction of future research is presented, which will be useful for researchers and engineers working in future microgrids and smart grids. This review will guide to select appropriate components to develop an SST for a particular application.

It is necessary to detect the fault disturbances as quick as possible to improve performance of microgrid. Keeping an eye to the above issue this paper introduces a novel technique for the detectio...

In industrial and utility power system it has been observed that harmonics build a major role in reducing the quality of power. These harmonics are caused because of increasingly utilize of nonlinear loads connected to the power system. In this context, active power filters play a very significant role for improvement in power quality. Moreover, at transmission ground, there is a high requirement to control reactive power and voltage stability. Conventionally, passive and active filters (shunt and series filters) were used for the development of power quality. But, they suffered from the issues like resonance, fixed compensation, and other PQ problems. Therefore, to minimize these issues, a hybrid combination of filters using passive and active filters is designed. In this paper, a comparative study of two hybrid model of HAPF is done based on current control techniques like d-q and p-q theory under different operating conditions. These results are again compared with a new estimation technique proposed in this paper well known called as recursive least square (RLS) harmonic estimation technique. The amplitude and phase angle of both the fundamental and harmonic currents are estimated with the proposed RLS technique. At the point of common coupling (PCC) the signal which is composed with harmonics is estimated with and without HAPF. Finally, it is analysed from the observation that the load current and supply current is improved significantly with a decrease of total harmonic distortion (THD) under different operating scenarios.

Solar energy is going to play a measure role in the future global energy supply. Its acceptance has already been on rise in developing countries like India, where there is acute shortage of energy due to economic and other climatic reasons. Forecasting or predicting the future output of solar energy is a much needed step to integrate high insolation of solar energy to the nation's power grid. Due to the fluctuating nature of solar energy, an efficient use is possible depending on reliable forecast information and its availability in various time and spatial scales. The current status of forecasting of solar irradiance for energy generation proposes a review of solar radiation prediction and its application in a rapidly increasing economy like India. Various models are developed for analysis which can be developed either by empirical, soft computing or by simulation approach.

This paper discusses the power management of standalone PV based Microgrid.PV based Microgrids can be of great importance in rural areas which are devoid of power through centralized Grid. Even a mesh microgrid can be devised with Solar PV systems located on different houses interconnected together. But there are certain challenges like voltage instability and other power quality problems which are to be addressed time to time to protect the Microgrid from collapsing. Addition of diesel generator help in resoration of voltage stability of the system through reactive power management. Further inclusion of FACTS devices improve the system stability as well as the damping of the system. System's behavior during different loading conditions has been monitored and contribution of solar power with different irradiations has been watched.

This paper presents a dynamic stability study in a solar energy based power system connected to infinite bus based on optimal design of a Static Var Compensator (SVC). In the proposed study, SVC is incorporated in order to improve the rotor angle and voltage oscillations because of different disturbances created in the power system. A new computational hybrid optimization approach using Particle Swarm Optimization (PSO) and Gravitational Search (GS) technique is considered for designing an optimal SVC damping controller for an improved dynamic performance. The optimization technique is used for tuning the gains of proportional integral derivative (PID) controller. Transient oscillation results for conventional PID, PSO optimized PID and PSO-GS based PID are compared analytically as well as quantitatively. It is observed that the proposed PSO-GS based PID controller is robust and effective in minimizing the oscillations in the system as compared to the other two and thus improves the stability.