Study on the design and switching dynamics of hysteresis current controlled four‐leg voltage source inverter for load compensation

Abstract

In a variable switching frequency control scheme, it is challenging to design the voltage source inverter (VSI) parameters without knowing the maximum and minimum switching frequencies. The switching frequency variation depends on the system parameters. Therefore, the expression for frequency variation in one inverter topology does not hold in other topologies. The design of hysteresis current controlled four-leg shunt active power filter (APF) requires the switching dynamics analysis to ensure satisfactory performance of the inverter. In this study, a detailed analysis on the switching dynamics of hysteresis current controlled four-leg VSI and design of various inverter components for compensating unbalanced and nonlinear loads are presented. The results obtained from these analyses can be used in any applications involving hysteresis current controlled four-leg VSI. These results are supported by detailed simulation studies conducted on a three-phase four-leg shunt APF system using Matlab/Simulink. The theoretical studies and design of passive components are also verified by conducting experiments on a prototype of four-leg shunt APF developed in the laboratory.

Simplified Predictive Direct Power Control of Three-Phase Three-Level Four-Leg Grid Connected NPC Converter

“…The voltage-oriented control (VOC) schemes are widely used for the 4L-GCC control [8], [9]. The VOC is based on PI controllers, coordinate transformation, and modulation stage.…”

Model predictive control with constant switching frequency for four‐leg DSTATCOM using three‐dimensional space vector modulation

“…Finally, FL-DSTATCOM is suitable for both 3P3W and 3P4W systems, however, it requires two additional switches compared to three-leg and TPSC DSTATCOM. The other advantages of this topology are better controllability, simple structure, easy control and the absence of capacitor voltage balancing problem unlike TPSC topology [7,18,19]. Therefore, FL-DSTATCOM is the best suited topology to compensate for the power quality issues in 3P4W distribution system.…”

Single‐stage high‐frequency‐isolated three‐phase four‐leg buck–boost inverter with unbalanced load

“…With only adding two switches to the three-phase three-leg inverter, the three-phase four-leg inverter becomes a pervasive and satisfactory solution to handling the neutral current caused by the unbalanced load with high utilisation of DC voltage and high power density [6][7][8][9][10]. Various control and modulation methods have also been studied to improve its steady-state and dynamic performance, including dynamic hysteresis current control, model predictive current control, and so on [11][12][13][14][15][16][17]. The authors of [12] studied the hysteresis current control method that minimises switching operations to compensate non-linear load.…”