Majlesi Journal of Energy Management
Volume:1 Issue: 1, Mar 2012

This paper presents integration of grid distribution network in Indian scenario with solar power converter to meet the additional electrical energy demand of a household in urban as well as rural sector which is increasing day by day due to rapid growth of population. A simulation approach using PSIM software has been adopted to explore the feasibility of developing such system to work as a supplementary source. The SPWM conversion technique used in the development of proposed solar power converter produces a grid quality usable AC power supply from PV and /or battery source. The optimal design of system components like PV, battery and inverter etc has resulted in a cost effective system and offer a stabilized consistent power supply for household loads. The PV Converter system can also work as a standalone system in remote areas of Indian villages where grid is either not existing or its availability is very poor and grid extension or expansion is not possible due to various technical and economic reasons.

This paper deals with the simulation of eight bus system having fixed capacitor and thyristor controlled reactor. The system is modeled and simulated using MATLAB. The simulation results are presented. The power and control circuits are simulated. The current drawn by the TCR varies with the variation in the firing angle. The simulation results are compared with the theoretical results.

Any weakness of insulation in a power transformer winding may result in winding deformation and hence, in the failure of the transformer. Insulation failure arises due to over voltages, notches, glitches, etc. Comparison of recorded neutral currents at reduced and full voltage reveals this integrity and any differences in wave shapes of the recorded neutral current signals shows the failures of winding insulation of the power transformer. Any shift in the recorded waveforms between reduced and full voltage confirms the existence of fault. In the present work, the recorded neutral current waveforms obtained from a generator transformer have been considered for analysis. Faults have been created in the discs of the High Voltage windings at specific locations. A low impulse voltage is applied to the high voltage winding and the neutral currents for the healthy case and the faulted discs windings have been recorded using digital oscilloscope. These recorded neutral current waveforms are analyzed using wavelets for fault identification. The component of the noise which is inherent in the signal during recording was isolated using Daubechies3 wavelet and these de-noised signals were analyzed further using Daubechies3 wavelet to identify the fault in the winding.

In this paper to determine the location and value of the capacitors, a new method is used. Two membership functions are defined for voltage and loss of distribution system. Using fuzzy sets, the best bus for compensation is selected and according to objective function, the capacitor value is obtained. The sensitivity of membership functions to their weight coefficients is considered and by varying them, the capacitor location and its value vary. Using genetic algorithm, the best weight coefficients are determined. This method is evaluated on 9-bus and 34-bus networks and the results are compared to results of previous methods.

Electromagnetic compatibility (EMC) is always a great concern for power electronics circuit designers. It has become an engineering discipline and it should be considered in the first stage design of converter. Designing becomes more complex and challenging and requires communication between EMI and Power electronics experts. In this paper, major issues related in designing a power converter are discussed. Apart from losses and harmonics, electromagnetic interference (EMI) is the major and most important aspect of a power converter. These issues affect size, cost, efficiency, reliability and quality of a power converter.

In today’s competitive environment, it is imperative to capitalize on advances in technology that allow new technique for maintenance of the electrical equipments.. As the entire energy has to pass through the transformer, it becomes necessary that transformer must give long and trouble free service therefore it is very important that transformer must receive a reasonable degree of attention regarding its health. During recent years policy of utilities is changing under the pressure of economical consideration. There is common tendency of moving the time based to the condition based maintenance to reduce cost and also to prevent sudden failure particularly catastrophic, ones that follow main insulation faults, arcing & heating. Also sometimes under compulsion it is necessary to keep transformer in operation when indication of arcing, heating, partial discharge are prevailing. Condition monitoring is only tool to handle such situation. Paper presents some newer on line diagnostics methods. Paper describes the various on line condition monitoring technique such as Dissolved gas Analysis, Moisture monitoring, Thermal scanning, Partial discharge measurement, Bushing monitoring along with some case studies.