Comparison of New Multilevel Inverter Topology with Conventional Topologies Used for Induction Heating System

In this article, a comparison of innovative multilevel inverter topology with standard topologies has been conducted. The proposed single phase five level inverter topology has been used for induction heating system. This suggested design generates five voltage levels with a fewer number of power switches. This reduction in number of switches decreases the switching losses and the number of driving circuits and reduce the complexity of control circuit. It also reduces the cost and size for the filter used. Analysis and comparison has been done among the conventional topologies (neutral clamped and cascade H-bridge multilevel inverters) with the proposed inverter topology. The analysis includes the total harmonic distortion THD, efficiency and overall performance of the inverter systems. The simulation and analysis have been done using MATLAB/ SIMULINK. The results show good performance for the proposed topology in comparison with the conventional topologies.

Analisa Dampak Penggunaan Filter L-C-L Terhadap Kinerja Pengatur Kecepatan Motor Induksi

Pengaturan kecepatan motor dilakukan dengan mengubah tegangan input, ataupun frekuensi yang terdapat pada motor. Maka hal yang lebih mungkin dilakukan adalah dengan mengubah kecepatan motor dengan mengubah frekuensi pada sumber stator. Inverter bisa digunakan sebagai pengontrol yang dapat mengatur kecepatan pada motor induksi, topologi inverter yang digunakan adalah diode clamped multilevel inverter tetapi inverter masih mengandung harmonisa yang cukup tinggi, sehingga inverter memerlukan filter untuk mengurangi besarnya harmonisa. Filter yang digunakan adalah filter pasif L-C-L, Kapasitas atau ukuran dari filter yang dibutuhkan akan semakin besar berbanding lurus dengan besar daya yang digunakan.Kata kunci — Diode clamped multilevel inverter, Harmonisa, Filter, Pengaturan kecepatan.

Solar Photovoltaic System-Based Reduced Switch Multilevel Inverter for Improved Power Quality

This paper deals with a reduced switch multi-level inverter for the solar photovoltaic system-based 127-level multi-level inverter. The proposed technique uses the minimum number of switches to achieve the maximum steps in staircase AC output voltage when compared to the flying capacitor multi-level inverter, cascaded type multilevel inverter and diode clamped multi-level inverter. The use of a minimum number of switches decreases the cost of the system. To eliminate the switching losses, in this topology a square wave switch is used instead of pulse width modulation. Thereby the total harmonic distortion (THD) and harmonics have been reduced in the pulsating AC output voltage waveform. The performance of 127-level MLI is compared with 15 level, 31-level and 63-level multilevel inverters. The outcomes of the solar photovoltaic system-based 127-level multi-level inverter have been simulated in a MATLAB R2009b environment.