Minimizing THD of multilevel inverters with optimal values of DC voltages and switching angles using LSHADE-EpSin algorithm

Multilevel inverters are mainly used for DC to AC power conversion and these inverters can be classified into types current source inverter (CSI) and voltage source inverter (VSI). Voltage source inverters are more common in power industry to convert lower levels of DC voltages into higher levels of AC voltages. In the process of conversion widely implemented pulse width modulated (PWM) switching technique of DC sources introduces harmonics in inverter output voltage. Total harmonic distortion (THD) is a measure of harmonic pollution in the power system and it is observed that variations in both DC voltages and switching angles of inverter affect the THD of inverter output voltage. Cascaded multilevel symmetric inverters ideally have DC sources all equal and constant. This paper considers inverters where DC sources can be unequal, a justifiable and realistic supposition. Optimal values of DC voltages and switching angles, which minimize THD level, are found using evolutionary algorithm. An advanced form of Differential Evolution (DE), called LSHADE-EpSin, is applied for the optimization problem. SHADE is a success history based parameter adaptation technique of DE. LSHADE improves the performance of SHADE with linearly reducing the population size in successive generations. LSHADE-EpSin introduces an additional adaptation technique for control parameters of the evolutionary algorithm. The algorithm has successfully been implemented for higher levels of inverters considered in the scope of our research study.

[1]  P. N. Suganthan,et al.  Differential Evolution Algorithm With Strategy Adaptation for Global Numerical Optimization , 2009, IEEE Transactions on Evolutionary Computation.

[2]  Fang Lin Luo,et al.  Advanced DC/AC Inverters: Applications in Renewable Energy , 2013 .

[3]  Zainal Salam,et al.  A review of soft computing methods for harmonics elimination PWM for inverters in renewable energy conversion systems , 2014 .

[4]  Alex S. Fukunaga,et al.  Improving the search performance of SHADE using linear population size reduction , 2014, 2014 IEEE Congress on Evolutionary Computation (CEC).

[5]  Mehmet Fatih Tasgetiren,et al.  Differential evolution algorithm with ensemble of parameters and mutation strategies , 2011, Appl. Soft Comput..

[6]  Alex S. Fukunaga,et al.  Success-history based parameter adaptation for Differential Evolution , 2013, 2013 IEEE Congress on Evolutionary Computation.

[7]  A. Kavousi,et al.  Application of the Bee Algorithm for Selective Harmonic Elimination Strategy in Multilevel Inverters , 2012, IEEE Transactions on Power Electronics.

[8]  Robert G. Reynolds,et al.  An ensemble sinusoidal parameter adaptation incorporated with L-SHADE for solving CEC2014 benchmark problems , 2016, 2016 IEEE Congress on Evolutionary Computation (CEC).

[9]  V. Agelidis,et al.  Selective Harmonic Elimination PWM Control for Cascaded Multilevel Voltage Source Converters: A Generalized Formula , 2008, IEEE Transactions on Power Electronics.

[10]  T. H. Abdelhamid,et al.  Elimination of harmonics in multilevel inverters with non-equal DC sources using PSO , 2008, 2008 13th International Power Electronics and Motion Control Conference.

[11]  Arthur C. Sanderson,et al.  JADE: Adaptive Differential Evolution With Optional External Archive , 2009, IEEE Transactions on Evolutionary Computation.

[12]  S. Fathi,et al.  Application of OMTHD on the line voltage of cascaded multi-level inverters with adjustable DC sources , 2010, 2010 5th IEEE Conference on Industrial Electronics and Applications.

[13]  Hadi Vadizadeh,et al.  Calculating the Formula of Line-Voltage THD in Multilevel Inverter With Unequal DC Sources , 2011, IEEE Transactions on Industrial Electronics.

[14]  Fang Lin Luo,et al.  Investigation on best switching angles to obtain lowest THD for multilevel DC/AC inverters , 2013, 2013 IEEE 8th Conference on Industrial Electronics and Applications (ICIEA).

[15]  Fang Zheng Peng,et al.  Multilevel inverters: a survey of topologies, controls, and applications , 2002, IEEE Trans. Ind. Electron..