New Three-Phase Symmetrical Multilevel Voltage Source Inverter

Abstract

This paper presents a new design and implementation of a three-phase multilevel inverter for distributed power generation system using low frequency modulation and sinusoidal pulse width modulation as well. It is a modular type and it can be extended for extra number of output voltage levels by adding additional modular stages. The impact of the proposed topology is its proficiency to maximize the number of voltage levels using a reduced number of isolated dc voltage sources and electronic switches. Moreover, this paper proposes a significant factor , which is developed to define the number of the required components per pole voltage level. A detailed comparison based on is provided in order to categorize the different topologies of the s addressed in the literature. In addition, a prototype has been developed and tested for various modulation indexes to verify the control technique and performance of the topology. Experimental results show a well-matching and good similarity with the simulation results.Index Terms-Low frequency modulation, multi-level inverter, multi-level inverter comparison factor, sinusoidal pulse-width modulation (SPWM), symmetrical DC power sources, three-phase. NOMENCLATURESComponents per pole voltage level. Number of voltage levels per pole. Capacitors count. Diodes count. Switching devices count. dc-power supplies count. Transformers count.

Grid-Connected Harmonic Current Suppression of Permanent Magnet Direct Drive Wind Power Converter Based on Current Cross-Coupling Control

“…For the q-axis harmonic current control, the d-axis current can be adjusted by closedloop PI, and the corresponding q-axis control voltage can be obtained by adding the q-axis resistance compensation term. Combining (22) to (25), the harmonic current control (26) to (29) of the grid-side converter in multi-synchronous rotating coordinate system can be further obtained, as follows.…”

“…In the control system, the low pass filter is used to detect the dq axis component of the harmonic current. Because the lowest frequency of the AC current component of the dq axis is 300Hz in each rotating coordinate system, the cut-off frequency of the lowpass filter in each harmonic detection channel is 50 Hz, which can not only ensure the accurate DC component and reduce the interaction between the harmonic currents, but also make the system have better dynamic characteristics [26]- [30]. For the fundamental current control of the control system, in order to effectively filter out the harmonic current in the fundamental current and make the fundamental current have excellent dynamic regulation ability, It is necessary to ensure that the fundamental current control has a certain response bandwidth.…”

A Different Voltage-Source Power Inverter with Carrier Based SPWM for Open-End Connection Loads

“…A multilevel inverter is a type of inverter working to produce ac voltage or ac current waveforms with three or more level numbers of waveforms [1][2][3]. When the input source is a dc voltage, the inverter is categorized as a voltage source inverter.…”

A novel generalized concept for three phase cascaded multilevel inverter topologies

“…Owing to the several advantages of cascaded multi-level inverters (CMLIs) including its ability to generate high voltage by utilizing low voltage power electronic devices [1][2][3], low voltage stress (dv⁄dt) on the switches [4,5], and low harmonic distortion in the output waveforms, applications of CMLIs in power systems have received much attention and several CMLI topologies have been recently proposed and published in the literature [5][6][7][8][9][10][11][12][13]. Based on the operating principle and the structure, CMLI topologies can be classified into three groups: (1) topologies with level generator and polarity generator [5,7,13,14]; (2) modified CMLI topologies [6,8,9,12,[15][16][17][18] and (3) three phase CMLI topologies [1,3,10,[19][20][21][22].…”