Stochastic adaptive-service level agreement-based energy management model for smart grid and prosumers.

The growing issue of demand-supply management between the prosumers and the local energy market requires an efficient and reliable energy management model. The microlayers, such as prosumers, energy districts, and macro players, namely retail dealers and wholesale dealers play a pivotal role in achieving mutual benefits. The stochastic nature of renewable energy generation in energy districts requires an effective model that can contemplate all stochastic complexities. Therefore, this paper proposes a mutual trade model between energy districts and smart grid to authorize the prosumers for mutual energy transactions under the stochastic adaptive-service level agreement. Moreover, multiple smart contacts are developed between the stakeholders to design adaptability and stochastic behavior of wind speed and solar irradiance. The real-time adaptations of the stochastic adaptive-service level agreement are based on technical beneficial feasibility and achieved through stochastic and adaptive functions. The optimized solution based on a genetic algorithm is proposed for the energy cost and energy surplus of prosumers and output parameters of the mutual trade model (grid revenue). In the context of mutual benefits associated with balanced demand and supply, the economic load dispatch and simplex method maximization are used for optimized demand-supply energy management. Moreover, the effectiveness of the proposed adaptive and stochastic mutual trade model is validated through simulation and statistical analysis.

Evaluating a Hybrid Circuit Topology for Fault-Ride through in DFIG-Based Wind Turbines.

Large-scale wind power integration has raised concerns about the reliability and stability of power systems. The rotor circuit of a doubly fed induction generator (DFIG) is highly vulnerable to unexpected voltage dips, which can cause considerable electromotive force in the circuit. Consequently, the DFIG must fulfil the fault-ride through (FRT) criteria to ensure the system's performance and contribute to voltage regulation during severe grid outages. This paper provides a hybrid solution for DFIG wind turbines with FRT capabilities, using both a modified switch-type fault current limiter (MSFTCL) and a direct current (DC) chopper. The proposed system has the merit of keeping the rotor current and the DC-link voltage within the permissible limits, enhancing the FRT capability of generators. Moreover, the boundness of supply voltage into its reference value ensures dynamic stability during symmetric and asymmetric grid failures. Further, electromagnetic torque variations are significantly reduced during fault events. Finally, the performance validation of the proposed scheme is performed in a simulation setup, and the results are compared with the existing sliding mode control (SMC) and proportional-integral (PI) controller-based approaches. The comparison results show that a hybrid strategy with advanced controllers provides superior performance for all critical parameters.

Surgical resection of orbital primitive neuroectodermal tumor without adjuvant chemotherapy.

Primitive neuroectodermal tumor (PNET) of the orbit is a very rare entity. We report a case of a 10-year-old boy having progressive protrusion of the eyeball, restricted ocular motility, ptosis, and ocular pain for 2 months. On examination, a fixed, nontender, firm, hyperemic, nonpulsatile globular mass was palpated in the superomedial quadrant of the orbit. Computed tomography scans of the orbit depicted a well-defined, soft tissue density lesion within the orbit without evidence of any bone defect or erosion. Surgical resection of the encapsulated lesion through anterior orbitotomy followed by histopathology and immunohistochemistry examination confirmed the diagnoses of PNET. The patient has been on regular follow-up for 2 years and has shown no sign of recurrence.

A glued technique of external dacryocystorhinostomy.

PURPOSE: Fibrin glue was used for anastomosis of lacrimal sac and nasal mucosal flaps and was compared with the conventional suture technique in external dacryocystorhinostomy. METHODS: A prospective interventional randomized control study in which 50 consecutive patients of primary acquired nasolacrimal duct obstruction (PANDO) were equally allocated into two groups. The case group underwent glued technique of external dacryocystorhinostomy (Ext DCR) in which fibrin glue was used for the apposition of the anterior lacrimal sac and nasal mucosal flaps. In the control group, conventional technique of Ext DCR was used to suture the flaps. Functional success was assessed by improvement in epiphora and fluorescein dye disappearance test (FDDT), whereas anatomical success was assessed by lacrimal irrigation and endoscopic view of the osteotomy site. RESULTS: The anatomical success in both the groups was 92%, whereas the functional success was 92% in the case group and 88% in the control group. The difference in the success rates between the two groups was statistically non-significant. CONCLUSION: Glued technique of Ext DCR is a simple and easy alternative to suturing of the flaps. Though the final outcome was comparable in both the groups, glue can be especially useful in uncooperative cases, in cases of excessive bleeding, or in situations where the flaps are very thin or have become friable.