On-Line Application of SHEM by Particle Swarm Optimization to Grid-Connected, Three-Phase, Two-Level VSCs with Variable DC Link Voltage

Abstract

This paper is devoted to an otablen-line application of the selective harmonic elimination method (SHEM) to three-phase, two-level, grid-connected voltage source converters (VSCs) by particle swarm optimization (PSO). In such systems, active power can be controlled by the phase shift angle, and reactive power by the modulation index, against variations in the direct current (DC) link voltage. Some selected, low-odd-order harmonic components in the line-to-neutral output voltage waveforms are eliminated by calculating the SHEM angle set continuously through the developed PSO algorithm on field-programmable gate array (FPGA)-based computing hardware as the modulation index is varied. The use of powerful computing hardware permits the elimination of all harmonics up to 50th. The cost function of the developed PSO algorithm is formulated by using an optimum number of particles to obtain a global optimum solution with a small fitness value in each half-cycle of the grid voltage and then updating the SHEM angle set at the beginning of the next full-cycle. Since the convergence of the solution to a global minimum point depends upon the use of correct initial values especially for a large number of SHEM angles, a generalized initialization procedure is also described in the paper. Theoretical results are verified initially using hardware co-simulation. They are also tested using a small scale photovoltaic (PV) supply prototype developed specifically for this purpose. It is demonstrated that the 5th, 7th, 11th, 13th, 17th, and 19th sidekick harmonics are eliminated by on-line calculation of seven SHEM angles through the developed PSO algorithm on a moderately powerful XEM6010-LX150, USB-2.0-integrated FPGA module. All control and protection actions and the calculation of SHEM angles are achieved by a single FPGA chip and its peripherals within the FPGA board.

Applications of Power Electronics

“…With the high penetration of power electronic systems, another aspect that again is attracting increased attention is the mitigation and control of the harmonics and EMI noise emissions of power converters. In [41], the utilization of an online selective harmonic elimination (SHE) method and particle swarm optimization to reduce harmonics is addressed, while in [42], a comprehensive review on control strategies for mitigating the dead-time effect on power converters to improve the total harmonic distortion of output waveforms is presented. With respect to EMI, modeling and proper EMI filter design in order to comply with international standards, which is of high importance, is addressed in [43,44].…”

Applications of Power Electronics

“…This special issue with 49 published articles has gained a great deal of attention from both academia and industry, clearly showing the growth in significance of "Applications of Power Electronics" in the current research and development arena. The accepted articles cover broad topics in the field of power electronics, and they are categorized into seven different focus areas: T1: Fault Diagnosis, Reliability and Condition Monitoring [14][15][16][17]; T2: Modeling, Control and Design of Power Electronic Converters [18][19][20][21][22][23][24][25]; T3: Electrical Machines, Drives and Traction Systems [26][27][28][29][30][31][32][33][34]; T4: Distributed Power Generation and e-Grid [35][36][37][38][39][40][41][42][43][44][45][46]; T5: Emerging Power Electronic Technologies (Pulsed Power, Energy Storage, Others) [47][48][49][50][51]; T6: Energy Access and Micro-Grids [52][53][54][55][56]; T7: Wireless Power Transfer Systems…”

Exploring the Limits of Floating-Point Resolution for Hardware-In-the-Loop Implemented with FPGAs

“…Digital control for power converters has been growing during the past two decades [1][2][3][4][5]. Despite all the advantages of digital control, the debugging process of this type of control is more complex because the power converter is an analog system while the control is digital.…”