T.N. Padmanabhan Nambiar

Harmonic state estimation in a distribution generation system environment

Harmonics degrade the power quality of Power Systems. It becomes vital to compute the harmonic generated by non linear loads present in the Power System. With renewable energy becoming the future of the power technology, a Harmonic estimation in a distributed generation environment becomes indispensable. Harmonic State Estimation (HSE) in such an environment is attempted using time structured Independent Component Analysis (ICA) employing least information about the power system topology. Various ICA algorithms are used for HSE, of which COMBI (Combination of WASOBI and EFICA) is applied to a four bus model and is found to be more accurate than JADE in terms of certain performance measures. It is proposed to implement the HSE problem with suitable selection algorithms to intensify the performance.

Single stage grid connected solar micro-inverter with two level fuzzy logic MPPT controller

This paper presents a single stage grid connected three phase micro inverter for transfer of power from a solar array to grid controlled by a two level fuzzy logic controller. The system utilizes a line commutated inverter, thus the need for synchronization modules are eliminated. A fuzzy logic controller is designed and developed to track the maximum power from the PV panel and generate an appropriate control variable which is compatible for the switching of thyristorised converter. A two level logic is chosen for faster convergence with variable correction steps for the fuzzy logic controller. The maximum power point voltage window is identified from the PV array characteristics and the rule base for the two levels is developed. The system is tested for two array ratings of 5.8 kW and 8.7 kW to bring out the generic nature of the proposed fuzzy controller for power tracking. The micro inverter system is executed in MATLAB/Simulink for varying ambient conditions of the PV panel and the power balance is verified as proof of theory.

Noise Based Independent Component Analysis Model for Harmonic Current Estimation

In a deregulating environment, Independent Component Analysis (ICA) is used to estimate the harmonic currents of non linear loads as it does not require information about the topology of the network. However, analysis is done by ignoring the effect of various noises that creep into the measurement system. In the present work, the effect of environmental noise on a simple interconnected power system with five buses is taken up. The two algorithms namely Fast ICA (FICA) and Efficient Variant Fast ICA(EFICA) are used for the analysis. A fixed noise is added and it is eliminated using whitening technique The simulation results of both algorithms show that noise elimination by whitening technique is highly successful. However, EFICA gives better results than FICA when random fluctuations of load exist rather than when fixed variations exist.