Harmonic analysis and FPGA implementation of SHE controlled three phase CHB 11-level inverter in MV drives using deterministic and stochastic optimization techniques

Abstract

With the advancements in semiconductor technology, high power medium voltage (MV) Drives are extensively used in numerous industrial applications. Challenging technical requirements of MV Drives is to control multilevel inverter (MLI) with less Total harmonic distortion (%THD) which satisfies IEEE standard 519-1992 harmonic guidelines and less switching losses. Among all modulation control strategies for MLI, Selective harmonic elimination (SHE) technique is one of the traditionally preferred modulation control technique at fundamental switching frequency with better harmonic profile. On the other hand, the equations which are formed by SHE technique are highly non-linear in nature, may exist multiple, single or even no solution at particular modulation index (MI). However, in some MV Drive applications, it is required to operate over a range of MI. Providing analytical solutions for SHE equations during the whole range of MI from 0 to 1, has been a challenging task for researchers. In this paper, an attempt is made to solve SHE equations by using deterministic and stochastic optimization methods and comparative harmonic analysis has been carried out. An effective algorithm which minimizes %THD with less computational effort among all optimization algorithms has been presented. To validate the effectiveness of proposed MPSO technique, an experiment is carried out on a low power proto type of three phase CHB 11- level Inverter using FPGA based Xilinx’s Spartan -3A DSP Controller. The experimental results proved that MPSO technique has successfully solved SHE equations over all range of MI from 0 to 1, the %THD obtained over major range of MI also satisfies IEEE 519-1992 harmonic guidelines too.

Improving power quality with reducing output harmonics for electric vehicle applications by using bacteria foraging algorithm

“…It was found that BFA consistently outperformed PSO under all test systems and configurations. It can be observed that BFA converges to a better solution in a faster time (Vesapogul et al, 2013). This trend was consistently observed with all problems attempted.…”

Selective Harmonic Elimination for a Single-Phase 13-level TCHB Based Cascaded Multilevel Inverter Using FPGA

“…Usually, this is done offline, using optimization techniques such as the Newton-Raphson (NR) method [14]- [17]. More complex techniques such as the genetic algorithm (GA) [15], [18]- [20] and the particle swarm optimization (PSO) [15], [21], [22] have also been demonstrated. Although these new techniques are fast in determining the optimized angle, the solutions only minimize the harmonics rather than eliminate them.…”

“…Since the effectiveness of the SHE method depends heavily on the switching angle, various algorithms have been developed for determining the optimum switching angles [14], [15]. Usually, this is done offline, using optimization techniques such as the Newton-Raphson (NR) method [14]- [17].…”

“…This limitation can be resolved with a field-programmable gate array (FPGA) as an alternative to programmable logic device (PLD) and application specific integrated circuit (ASIC) technologies. FPGAs are digital hardware-based devices and they have become an increasingly popular technology in digital prototyping for multilevel inverters [15], [28] due to their speed and flexibility.…”

Generalized Selective Harmonic Elimination Modulation for Transistor-Clamped H-Bridge Multilevel Inverter

“…As these equations increase, solving them becomes a challenge. One of the most widely used techniques is the Newton-Raphson (NR) method [17], [18]. This is an iterative method to find complex roots in polynomials and roots of equations with several variables.…”