Distributed generations (DGs) are small generating plants which are connected to consumers in distribution systems to improve the voltage profile, stability improvement, reduction in power losses and economic benefits. The above benefits can be achieved by optimal placement of DGs. In this paper, a novel nature-inspired algorithm called elephant herding optimization algorithm is used to determine the optimal distributed generation size. It has been developed based on herding behaviour of elephant groups in nature. The proposed algorithm is tested on IEEE 15-, 33-and 69-bus test systems. The proposed algorithm with type III DG unit operating at 0.9 pf gives better results when compared with other methods in the literature.

With the advancements in semiconductor technology, high power medium voltage (MV) Drives are extensively used in numerous industrial applications. Challenging technical requirements of MV Drives is to control multilevel inverter (MLI) with less Total harmonic distortion (%THD) which satisfies IEEE standard 519-1992 harmonic guidelines and less switching losses. Among all modulation control strategies for MLI, Selective harmonic elimination (SHE) technique is one of the traditionally preferred modulation control technique at fundamental switching frequency with better harmonic profile. On the other hand, the equations which are formed by SHE technique are highly non-linear in nature, may exist multiple, single or even no solution at particular modulation index (MI). However, in some MV Drive applications, it is required to operate over a range of MI. Providing analytical solutions for SHE equations during the whole range of MI from 0 to 1, has been a challenging task for researchers. In this paper, an attempt is made to solve SHE equations by using deterministic and stochastic optimization methods and comparative harmonic analysis has been carried out. An effective algorithm which minimizes %THD with less computational effort among all optimization algorithms has been presented. To validate the effectiveness of proposed MPSO technique, an experiment is carried out on a low power proto type of three phase CHB 11- level Inverter using FPGA based Xilinx’s Spartan -3A DSP Controller. The experimental results proved that MPSO technique has successfully solved SHE equations over all range of MI from 0 to 1, the %THD obtained over major range of MI also satisfies IEEE 519-1992 harmonic guidelines too.

<p>This paper proposes a power management strategy of parallel inveters based system, to enhance the power generation capacity of the existing system with distributed energy sources one has to choose DG source based inverter connected in parallel with the existing system.Two DG sources PV, Fuel cells feeds the DC voltage to two parallel inverters connected to the grid. Fixed band hysteresis current control with Instantaneous p-q power theory is adopted to create an artificial environment. Two parallel inverters are able to deliver the harvested power from PV, FC to grid and able to balance the load Without communication between parallel inverters this controller having the capability of load following, the harmonic components of currents at output of inverter are also very low; this will automatically reduces the circulating currents between parallel inverters. Simulation studies are carried out to investigate the results of PV, FC systems connected to the utility grid.</p>

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This paper presents a novel control strategy to control DG integrated DVR (dynamic voltage restorer) for mitigation voltage quality problems. Power quality is the most concerning areas in power engineering and voltage quality is of prime focus. Voltage sag, voltage swell and harmonics in voltage causes deterioration in quality of voltage delivered to load. A minor disturbance in voltage profile can degrade the performance of load. Dynamic voltage restorer is a quick responsive custom power device for voltage quality improvement. Photovoltaic (PV) system is considered as DG and output voltage of PV system is boosted with a boost converter to support voltage source converter of DVR. DG integrated DVR with novel control strategy for mitigation of voltage sag, swell and voltage harmonic is presented in this paper. The power system model with DG integrated DVR is developed and results are obtained using MATLAB/SIMULINK. Results are discussed during pre and post sag/swell condition with compensation and THD in voltage is maintained within nominal values.

This paper presents a novel control strategy for the compensation of voltage quality issues in power system networks with AC drives. Voltage quality is one of the key parameter for power engineers and to deliver the power with good quality should be given at most priority. Voltage quality mitigation in power system network is done by employing dynamic voltage restorer (DVR). DVR consists of power switches and power switches are to be controlled. DVR in this paper is controlled using a novel control strategy. A novel control strategy can effectively control DVR by improving voltage quality reducing the adverse effects of voltage sag and voltage swell in power system networks. The paper presents the DVR controlled with novel control strategy for electrical machine (induction motor) drive load application.

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