Bipolar and unipolar schemes for confined band variable switching frequency PWM based inverter

Abstract

The single phase inverter performance through the unipolar and bipolar strategies has been previously analyzed based on the constant switching frequency pulse width modulation (CSFPWM). However, the confined band variable switching frequency PWM (CB-VSFPWM) is currently proposed as a new variable switching frequency PWM technique through unipolar strategy to facilitate the design of high order filter, to reduce the switching losses, and to reduce the current total harmonics distortion (THD) as well. To evaluate the performance of a single phase inverter based on the CBVSFPWM through bipolar strategy, this paper presents a comparative study of the CB-VSFPWM based inverter performance using the unipolar PWM and the bipolar PWM strategies. The study adopts MATLAB/Simulink to simulate the inverter and to analyze the simulation results in terms of harmonics spectrum, total harmonic distortion (THD), and fundamental components. The analysis of the study results gives an indication about the appropriate type of CB-VSFPWM strategy (unipolar PWM or bipolar PWM) to guarantee the desired performance of the connected inverter in terms of the electrical grid standards like THD, and harmonics spectrum of the inverter current.

Inter-connected AC/DC HMGS power management with 3-phase and 1-phase ILC

“…𝛥𝑃 𝑎𝑐,𝑙𝑜𝑎𝑑 = 𝛥𝑃 𝑔𝑒𝑛,𝑎𝑐 − 𝛥𝑃 𝑐𝑜𝑛 (7) Droop in frequency happens due to change in AC load demand, which causes change in generating power at AC sub grid side which is verified by (8).…”

“…A review paper discusses the power quality issues in bidirectional power flow in electric vehicle to grid [7]. To reduce the total harmonic distortion (THD) in a single-phase inverter a control technique confined band variable switching frequency pulse width modulation (CB-VSFPWM) is designed [8]. To extract maximum output power for a cluster MG, a modified reverse current flow method is proposed for radial system [9].…”

LCL-filter design and analysis for PWM recuperating system used in DC traction power substation

“…The voltage source inveter (VSI) circuit is presented in Figure 5 (b), this VSI is modulated with sinusoidal pulse-width-modulation (SPWM) technique. The fundamantal of SPWM technique had been presented in [27], [28]. Pure sinusoidal ac voltages, vg, are assumed as the voltage references in this simulation.…”