A New Family of Cascaded Transformer Six Switches Sub-Multilevel Inverter with Several Advantages

Abstract

Abstract-This paper presents a novel topology for cascaded transformer sub-multilevel converter.Eachsub-multilevel converter consists of two DC voltage sources with six switches to achieve fivelevel voltage. The proposed topology results in reduction of DC voltage sources and switches number. Single phase low frequency transformers are used in proposed topology and voltage transformation and galvanic isolation between load and sources are given by transformers. This topology can operate as symmetric or asymmetric converter but in this paper we have focused on symmetric state. The operation and performance of the suggested multilevel converter has been verified by the simulation results of a single-phase nine-level multilevel converter using MATLAB/SIMULINK.

A new isolated multilevel inverter based on cascaded three-phase converter blocks

“…Due to safety requirement, also it is desired that battery chargers is electrically-isolated by transformers which are operated at high frequency to reduce the cost and battery charger size because of space limitation on EVs [20]. For these reasons and more, new families of cascaded multilevel inverters have been proposed such as asymmetric cascaded multilevel inverter [14], combined H bridge cascaded transformer (CHBCT) multilevel inverter [13], cascaded multilevel inverter (CMI) [12], hybrid CMI inverter [11], and sub-multilevel inverter [9] with single dc source. Fig.…”

“…This construction is used to pile output voltage levels up by increasing number of transformers instead of increasing number of dc voltage sources. Moreover, the HBCT inverter provides filtering effect of harmonic components due to the leakage reactance of the cascaded transformers [9] and also provides electric isolation between output and source [13]. multilevel inverter [12].…”

“…In general, multilevel inverter topologies can be classified into four main groups: 1) diode-clamped, also known as neutral point clamped (NPC) inverters; 2) capacitor clamped inverters (also called flying capacitor inverters); 3) cascaded H-bridge multilevel inverter with separate dc sources; and 4) interconnected three phase inverters such as Hexagram converter [13,15,16,18]. Moreover, other types of topologies have also emerged such as the one that is implemented by means of cascading the fundamental structures called hybrid inverters [9,11,18]. A good summary on various multilevel converters can be found in [16].…”

“…These technologies are employed to provide power with low cost, reduced total harmonic distortion (THD), reduced dv/dt, optimal size, and low electromagnetic interference (EMI) without dissipating too much power [9][10][11][12][13][14][15][16][17][18]. In general, multilevel inverter topologies can be classified into four main groups: 1) diode-clamped, also known as neutral point clamped (NPC) inverters; 2) capacitor clamped inverters (also called flying capacitor inverters); 3) cascaded H-bridge multilevel inverter with separate dc sources; and 4) interconnected three phase inverters such as Hexagram converter [13,15,16,18].…”

Identification of Open-Switch and Short-Switch Failure of Multilevel Inverters through DWT and ANN Approach using LabVIEW

“…The major advantages of multilevel inverters are the reduction in harmonic distortion of output voltage waveform with increase in number of levels and flexibility to use a set of batteries or fuel cells in any intermediate stages [1][2][3]. Even though multilevel inverters have made their way successfully to the industrial applications with a proven technology, failure of power electronic switches and its fault diagnosis is still a hot research topic of many researchers.…”