Optimal Modeled Six-Phase Space Vector Pulse Width Modulation Method for Stator Voltage Harmonic Suppression

Dual Y shift 30 six-phase motors are expected to be extensively applied in high-power yet energy-effective fields, and a harmonic-suppressing control strategy plays a vital role in extending their prominent features of low losses and ultra-quiet operation. Aiming at the suppression of harmonic voltages, this paper proposes a six-phase space vector pulse width modulation method based on an optimization model, namely OM-SVPWM. First, four adjacent large vectors are employed in each of 12 sectors on a fundamental sub-plane. Second, the optimization model is constructed to intelligently determine activation durations of the four vectors, where its objective function aims to minimize the synthesis result on a harmonic sub-plane, and its constraint condition is that the synthesis result on the fundamental sub-plane satisfies a reference vector. Finally, to meet the real-time requirement, optimum solutions are obtained by using general central path following algorithm (GCPFA). Simulation and experiment results prove that, the OM-SVPWM performs around 37% better than a state-of-the-art competitive SVPWM in terms of harmonics suppression, which promise the proposed OM-SVPWM conforms to the energy-effective direction in actual engineering applications.Peer reviewe

FPGA based quasi z-source cascaded multilevel inverter using multicarrier PWM techniques

FPGA based Quasi Z-Source Cascaded Multilevel Inverter (Quasi Zs-CMLI) using multicarrier PluseWidth Modulation (PWM) techniques are presented in this paper. Multicarrier based PWM techniques have been proposed for seven level Quasi Zs-CMLI and implemented using Field Programmable Gate Array (FPGA). For generating gating pulses to the inverter switches, Phase Disposition (PD), Inverted Phase Disposition (IPD), Phase Opposition Disposition (POD) and Alternative Phase Opposition Disposition (APOD) techniques are programmed on FPGA. In the proposed system, three solar PV emulator modules are used. These are acting as input source to the inverter. Finally, THD comparison made between different carrier based modulation with shoot through and non-shoot through the states. The proposed quasi Zs-CMLI and PWM techniques are verified through MATLAB/Simulink. For confirmation of simulation results, A laboratory prototype model have been implemented using FPGA. The capture hardware results are matched with simulation results

Simulation and implementation of FPGA based hybrid asymmetric multilevel inverter

This work focuses on proposing a new structure for asymmetric multilevel inverter. In the proposed topology, a switched capacitor (SC) and conventional series inverter are combined and connected in cascade. The proposed multilevel inverter finds its application in photovoltaic inverters which has numerous advantages. Firstly, it converts power for AC requirements from comparatively low DC voltage sources and with lower number of switching devices. Second, with the removal of transformers normally used for stepping up the voltage of each inverter stage the weight, volume and size of the whole system is reduced as the proposed topology can double the input voltage without a transformer. Symmetrical step control method (SSCM) and fundamental switching frequency method (FSFM) are applied to this proposed topology to actuate the power electronic switches for effective control and monitoring of voltage levels generated at the output. The simulation is executed using MATLAB/SIMULINK software. It was found that FSFM modulation technique results in a lower value of Total Harmonic Distortion (THD). The switching strategy is implemented with an FPGA device for the experimental prototype. The simulation and experimental result of single-phase 25-level inverter is given to demonstrate the precise operation of the suggested topology

Experimental investigation on the performances of a multilevel inverter using a field programmable gate array-based control system

The Field Programmable Gate Array (FPGA) represents a valid solution for the design of control systems for inverters adopted in many industry applications, because of both its high flexibility of use and its high-performance with respect to other types of digital controllers. In this context, this paper presents an experimental investigation on the harmonic content of the voltages produced by a three-phase, five level cascaded H-Bridge Multilevel inverter with an FPGA-based control board, aiming also to evaluate the performance of the FPGA through the implementation of the main common modulation techniques and the comparison between simulation and experimental results. The control algorithms are implemented by means of the VHDL programming language. The output voltage waveforms, which have been obtained by applying to the inverter the main PWM techniques, are compared in terms of THD%. Simulation and experimental results are analyzed, compared and finally discussed