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This paper presents an investigation on mitigation of current harmonics, using Cascaded H-bridge Multilevel Converter (CHB-MLC)-based Shunt Active Power Filter (SAPF). Development and analysis of SAPF for harmonic compensation in distribution network for power quality improvement has been discussed. In the proposed work, transformer-less CHB MLC is used which reduces weight and cost of the system. Moreover, a novel controller based on average power method is adopted for generation of compensation active filter current. In order to generate switching signals, multi-carrier Alternate Phase Opposition Disposition (APOD) — Pulse Width Modulation (PWM) schemes are used. The proposed CHB-MLC SAPF reduces the source current THD below 5%. The results are simulated in MATLAB/Simulink and demonstrate the effective mitigation of current harmonics with APOD-PWM schemes. Opal-RT OP4500 real-time digital simulator is used to validate the proposed scheme under different steady state and transient conditions. [ABSTRACT FROM AUTHOR]

Multilevel inverter (MLI) is gaining rapid popularity in high/medium power applications due to low THD and high quality output waveform. Recently, the MLI topologies with reduced part count has attracted the researchers by offering higher number of output voltage level with reduced part count as compared to classical topologies (CHB, NPC and FC). It is observed that these recently proposed topologies are aimed to increase the output level with less number of components but the discussion over their suitability for a particular application is not yet explored completely. The main purpose of this paper is to provide an instructive review and analysis of existing MLIs with reduced part count. An exhaustive comparison of MLIs are assessed based on the number of switches, standing/blocking voltage across the switches, conduction losses, switching losses and cost. With the outcome of comparison results, suitable structure of MLI can be judged with reduced number of components and losses for given applications. [ABSTRACT FROM AUTHOR]

Reduced part count multilevel inverters (RPC-MLIs), an emerging technology for grid interfacing applications of renewable energy sources. RPC-MLIs overcome the limitations of conventional two-level and classical multilevel inverters (NPC, FC and CHB) by the use of reduced part counts for generation of same number of levels in the output. Focus of this paper is on to present review of the RPC-MLIs for researchers and engineers and classification of all the topologies. RPC-MLIs are compared considering its circuit complexity and performance. The comparison exposes advantages and disadvantages of topologies, as well as a wide spectrum for future research. This paper also draws the most potential topology in the field of grid integrated applications. Promising topology is simulated here under the same load and input source condition using real time simulator. [ABSTRACT FROM AUTHOR]

This paper deal with soft computing techniques such as artificial neural network (ANN), fuzzy logic controller (FLC) and proportional-integral (PI)-based static series voltage regulator (SSVR) for constant speed prime mover driven self excited induction generator (SEIG) feeding three phases linear and nonlinear loads. The constant speed prime mover such as biogas, biomass and gas-turbine driven standalone generating system has problem of poor voltage regulation. The SSVR is injects series voltage in to system to maintain constant source and load voltage with power quality improvement of source and load current. The SSVR is modeled using insulated gate bipolar junction transistor (IGBT)-based voltage controlled-voltage source converter (VC-VSC) with self supported DC bus. The A 7.5 kW, 415 V, 50 Hz asynchronous machine with voltage regulator and loads are designed, modeled and simulated in MATLAB environment. Simulated results are presented capability of an SEIG system with ANN, fuzzy and PI-based SSVR and their comparison. [ABSTRACT FROM AUTHOR]