All industrial drives need a controlled output and it can be achieved by controlling the input supply. In this regard, the inverter circuit plays an important role in the applications of industrial drives. The industrial drives are operated at high rated power and the conventional inverters cannot be applicable for high power demands because of the large dV/dt (rate of change of voltage) and more switching losses. Therefore, multilevel inverters are introduced for high power-medium voltage applications. For all AC drives the MLIs are reliable in operation. This MLI topology also reduces the harmonics and bearings stress of a motor with low dV/dt. In most applications multilevel inverters are used because we can get more number of voltage levels. To increase the number of voltage levels, circuit needs to have more switches. But, we have to optimize the switch count and switching operations. The power level of the inverter is limited due to high currents and stress. In this paper, we proposed a new circuit topology which enables the switches to be active at different voltage levels, causes reduction of the switching losses and also increases the efficiency of the inverter. In this we have presented two configurations for an eleven level MLI for three phase induction motor drive application. In this an individual DC source is connected for each bridge circuit of each phase in one configuration and only one common DC link is used for three phases in another configuration. With this the size, cost and complexity could be decreased. In both the configurations the controlled output of the inverter is connected to the induction motor drive. The circuits are modeled using Matlab/simulink software and corresponding output waveforms are analyzed for both configurations.

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<p>Penetration of multilevel inverters (MLI) in to high power and medium voltage application has been increasing because of its advantages. The conventional two levels inverter has high harmonic distortion which gives poor power quality. Lot of topologies has been developed to overcome the drawbacks of a two level inverter. These topologies include more number of switching devices which increases the design complexity and cost. The optimum design of inverter requires less number of switches with better quality in waveform. In this paper, a symmetrical five level and seven levels inverter configuration with simplified pulse width modulation technique is proposed. This proposed inverter requires less switches, less protection circuits along with low cost and size. The analysis of the inverter circuits is done by using Matlab/Simulink software. The synthesized staircase wave form is shown and total harmonic distortion (THD) is also measured.</p>

In present Electricity market Renewable Energy Sources (RES) are gaining much importance. The most common Renewable Energy Sources are Photo voltaic (PV), fuel cell (FC) and wind energy systems, out of these three PV systems PV system can implemented in most of the locations. Due to the power cuts and power disturbances in Distribution systems agriculture application is concentrated on PV based Energy system. The use of PV system is increasing day by day in agriculture application, due to their ease of control and flexibility. PV Electrification schemes also involves various subsidies in government national and international donors. Especially in Agriculture field by use of PV one can achieve higher subsidy. The output of PV system is low voltage DC to have high efficiency. The motors used in agriculture field are Induction Motors (IM) fed from Three phase AC supply, to boost the PV output we need a high voltage gain boost converter along with PWM inverter to Induction motor drive. Out of various DC-DC converter configurations interleaved boost converter is gaining much attention, due to its reduction in size and Electromagnetic Interference (EMI). In this work we are proposing a PV fed interleaved boost converter with PWM inverter for agriculture applications. The design process of interleaved boost converter is explain detail and compared with existing boost converter. A 10KW Power rating is choosing for the Induction motor drive and design calculations are carried out. A MATLAB/SIMULINK based model is developed for boost and interleaved boost converter and simulation results are presented, finally a scaled down hardware circuit design for interleaved boost converter and results are presented.

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