Swati Mishra

Voltage and frequency control of a micro-grid using a fuzzy logic controller based STATCOM equiped with battery energy storage system

It has become now a big challenging task to generate electricity in remote locations without the help of any external energy sources. One of the most effective solution to encounter this problem is the use of self excited induction generator producing electricity even in the absence of external energy source. Though self excited induction generator can act as a good isolated source of electricity, one of its greatest disadvantage is its fluctuating nature of voltage and frequency under varying load condition. Here in this paper we have considered a self excited induction generator along with a doubly fed induction generator with the former connected to the latter by a transmission line to form the proposed micro-grid system. The problems associated with the system are the varying nature of voltage and frequency which can be observed under different loading conditions such as linear load, nonlinear load, and dynamic load. The system also comprises of also a STATCOM with battery energy storage system which acts in order to balance the deviation resulted in the reactive and active power thereby maintaining the voltage and frequency. The controller used in this work is a fuzzy logic controller which carries out the controlling action through the STATCOM. The simulation for the above model is done in MATLAB / SIMULINK.

Pityriasis rosea like drug rash - a need to identify the disease in childhood.

Pityriasis rosea is a common dermatosis named by Gibert in 1860. It is an acute self limiting papulosquamous disease, probably infective in origin affecting healthy adolescents and young adults. It is characterized by distinctive skin eruptions and minimal constitutional symptoms. Drug induced pityriasis rosea tend to occur in older generation and resolution seen only after withdrawal of the offending drug. We report a case of 12-year-old boy with erythematous papules distributed over trunk and proximal arms after nimesulide therapy consistent with a clinical diagnosis of atypical pityriasis rosea. The relation of drug and development of pityriasis rosea is confirmed by dechallenge test of the suspected drug.

A sliding mode controller based STATCOM with battery storage for voltage and frequency stabilization in a micro-grid

Self excited induction generators are preferred to be one of the best machines for generation of electricity in remote and rural areas due to its capability of generating electricity without any external source. But on the other hand it is also a challenging task to maintain its voltage and frequency under load varying condition. In this paper we have considered a micro grid system with a Self excited induction generator and doubly fed induction generator as the source of generation connected by a transmission line. The Self excited induction generator is employed in a micro-hydro generation system where as the doubly fed induction generator is used for power conversion in a wind energy conversion system. A STATCOM with battery energy storage system is connected to the load bus acting as a compensator of active and reactive power, maintaining the voltage and frequency of system constant under different loading conditions such as linear load, nonlinear load and dynamic load. Sliding mode controller is used to control the STATCOM in a purpose to generate desired active and reactive power. The above system is modeled and simulated in MATLAB/SIMULINK and results are presented.