Mahajan Sagar

Bio: Mahajan Sagar is an academic researcher. The author has contributed to research in topics: Inverter & Topology (electrical circuits). The author has an hindex of 1, co-authored 1 publications receiving 4 citations.

Multilevel inverter with level shifting spwm technique using fewer number of switches for solar applications

Abstract: A multilevel inverter (MLI) is a popular inverter for solar based high power applications. The drawback of conventional H-bridge inverter is non-sinusoidal output voltage, which reduces the output quality of inverter. Later, the drawback of conventional Hbridge was overcome by conventional MLI. But, conventional MLI needs maximum number of diodes and switches. In order to overcome this drawback proposed MLI topology with level shifting sinusoidal pulse width modulation (SPWM) technique can be employed. Proposed MLI contain fewer number of switches and diodes, which helps in optimizing the circuit layout, reducing gate driver circuit for those switches. SPWM technique uses multicarrier waveforms with level shifting ensuring the reduction in total harmonics distortion (THD). In this Paper level shifting SPWM technique has been incorporated in which 5 kHz carrier wave is compare with 50Hz of sinusoidal wave with a modulation index of 0.8. THD of proposed 9-level inverter is 17.27% without filter and 4.29% with LC filter. Simulation of proposed inverter is carried out in MATLAB/SIMULINK.

Distribution Transformer Tap Setting Control using Particle Swarm Optimization

Abstract: Load uncertainty increases with the increase in power consumption, and it causes power losses, and low voltage profile in the radial distribution system. Improvement of voltage profile helps to reduce the power losses, DG and capacitor placement boost up the voltage at the consumer end. By the increase of distribution transformer tap settings the voltage profile of buses will be improved and reduces the power losses in the distribution system. But execs of voltage levels are causes higher power losses in the distribution system. This paper aims to reduce the real and reactive power losses in the distribution system by changing the transformer tap settings using the PSO algorithm. The proposed methodology examined on standard 15 bus distribution system with an EV charging station and DG system. Voltage-dependent load modeling is applied to a standard 15 bus test system.

Investigation of a Transistor Clamped T-Type Multilevel H-Bridge Inverter With Inverted Double Reference Single Carrier PWM Technique for Renewable Energy Applications.

Abstract: The Multilevel inverters (MLIs) are a new breed of power electronics converters. They are primarily used for the conversion of dc power to ac power. The two-level inverters are conventionally used to obtain ac power, but it requires operating the switches under very high switching frequency. Besides, the two-level inverter necessitates the use of LC filters with the switches operating under high dv/dt stress. The MLIs offer the advantage of utilizing several dc voltage sources to generate a stepped ac waveform with the proper arrangement of switches. Investigation of a Transistor Clamped T Type H-Bridge Multilevel Inverter (TC-TT-HB-MLI) with Inverted Double Reference Single Carrier PWM Technique (IDRSCPWM) for Renewable Energy Applications are discussed in this paper. A PV source is taken as an input to the TC-TT-HB-MLI. For different modulation indices like 0.85, 1 and 1.25, the FFT analysis is performed and presented, which corresponds to the variations in the irradiations from solar energy. A single unit of the TC-TT-HB-MLI is extended to a generalized MLI structure named Generalized Transistor Clamped T-Type H-Bridge Multilevel Inverter (GTC-TT-HB-MLI). The significant benefits of GTC-TT-HB-MLI are the multiple numbers of reductions in the switch count, and driver circuit counts for a higher number of MLI levels. Fast Fourier Transform (FFT) analysis is carried out on the MLI output to calculate the total harmonics distortion (THD). The experimental verification is performed using SPARTAN 3E-XCS250E; the gate signals are generated and provided to the switches.

Simplified sinusoidal pulse width modulation for cascaded half-bridge multilevel inverter

Abstract: This paper presents a simplified sinusoidal pulse width modulation (SSPWM) proposed to control a half-bridge multilevel inverter. This topology has less number of switching components compared to conventional types of multilevel inverter. It can be supplied from separated dc sources or renewable energy sources like solar energy via photovoltaic modules. This topology can be a symmetric or an asymmetric inverter via controlling the magnitude of dc sources. The asymmetric choice provides higher number of levels with less number of switches and dc sources. The proposed technique is a high switching frequency modulation based on the sinusoidal pulse width modulation. The SSPWM can be achieved using only one modulating, carrier signals and throughout a certain logic arrangement depends on number of levels. A laboratory system was built based upon the (NI PCI-6013) data acquisition controller and experimental results for single phase fifteen-level inverter show a well-matching and good similarity with the simulation results.

PV Array with Cascaded Multilevel Inverter and Medium Frequency Transformer for Grid Connection

Abstract: In the recent years, there has been an increased preference for the Photovoltaic power generation. As a result, the medium (>5 MW) and large (>10 MW) scale photovoltaic plants have garnered a lot of attention. The recent progress in power converters has resulted in grid integration of Renewable energy systems using Multilevel Inverter setup. This paper proposes a medium frequency transformer based multilevel inverter configuration to connect the PV system to a medium voltage grid. The proposed system will enhance the power quality, efficiency and also enable the medium voltage operation on the grid side. Keywords—Photovoltaic; Multilevel inverter; Grid integration; SPWM

Performance Analysis of a Water Pumping System Powered by Induction Motor and a PV Array

Abstract: Poor electricity supply in rural areas is still the biggest challenge India is facing. Farmers usually depend on supply or diesel generators for electricity which in-turns contribute to pollution. This aspect, on the other hand, allows for more efficient use of energy. In the absence of a utility grid, photovoltaic (PV) array-aided water pumping devices are becoming more common in residential and agricultural applications. The Performance analysis of a Solar PV-based Three-Phase Multilevel-Inverter for a water pumping system is proposed in this paper. Solar PV Array is used to generate dc voltage regardless of different irradiance and temperature while collecting maximum power from the sun. Reduced Switch Count Multilevel Inverter is used to produce three-phase ac output from the dc, produced by solar PV. This three-phase AC output is used for running an induction motor-based water pumping system for different loads. The simulation was done in MATLAB and the obtained results are found satisfactory at different load conditions.

Comparison of PWM Strategies for Three Level Inverters

Abstract: In this paper four PWM strategies for three level inverters are compared by simulation. The strategies differ by the waveform of the carries with offset for three of them. For the fourth the carriers are considered phase shifted. The comparison is performed taking into account the total distortion factor and the maximum value of the fundamental. Investigations are performed depending on the amplitude modulation factor.