International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 04 | Apr -2017
p-ISSN: 2395-0072
www.irjet.net
A Simplified Topology for Nine level Modified Cascaded H-bridge Multilevel Inverter with Reduced Number of Switch & Low THD Vivekkumar.A.Patel1, Prakash.K. Jariwala2, Divyakant.V.Parmar3, Pratik.B.Patel4, Priyank.D.Patel5 1Assistant
professor, electrical Engg, Mahavir Swami college of Engg. & Tech, Surat, Gujarat, India
2345Student,
electrical Engg., Mahavir Swami college of Engg. & Tech, Surat, Gujarat, India ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - Multilevel inverter is used in applications that
b) - Symmetric cascade H-bridge multilevel inverter
need high voltage and high current. The topology of multilevel inverter has several advantages such as lower THD, better output waveform and higher efficiency for a given quality of output waveform. Multilevel inverter has the advantage of its reduced number of devices compared to conventional cascaded H-bridge multilevel inverter. According to this we are going to make inverter for output of Single phase 9-level .Motor is driven with this inverter for testing purpose. The verification of MLI is done using MATLAB.
The unequal voltage balancing among the DC link capacitors that leads to an increase in clamping diodes as the voltage level increases, can be considered as the limitation of the diode clamped at a higher level. The flying capacitor multilevel inverter circuits becomes complex as a large number of capacitor are required at higher voltage levels. The cascade H-bridge multilevel inverter topology can be an acceptable option for high voltage applications. We are used the Symmetric cascade H-bridge multilevel inverter. Number of switches & Sources are reduce. Increase the efficiency of inverter. The single phase Hbridge cell; which is the building block for the cascade Hbridge inverter is associated with separate dc sources[5];[12]
Key Words: Cascade H-bridge ; Sources ; Switches & MATLAB simulation. 1.INTRODUCTION An inverter is an electric that changes direct power (DC) to alternating power (AC).The application areas for the inverters includes the Uninterrupted Power Supply(UPS),as inverter as power backup for home etc.The concept of multilevel Inverter (MLI) is kind of modification of two-level inverter. In multilevel inverters we don’t deal with the two level voltage instead in order to create a smoother stepped output waveform, more than two voltage levels are combined together. Smoothness of the waveform is proportional to the voltage levels, as we increase the voltage level the waveform becomes smoother[1].
2. SYSTEM OVERVIEW This paper proposes the comparison of different topologies of cascaded multilevel inverters. Table 2:- Per phase switching status of the proposed 9-level inverter Output
Multilevel inverter is very effective and practical solution for increasing power & reduction harmonic of AC waveform. Three types of Multilevel inverters: 1- Diode clamped 2- Flying capacitor 3- The cascade H-bridge a) - Asymmetric cascade H-bridge multilevel inverter
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