Fig 1 - uploaded by Sheikh Tanzim Meraj
Content may be subject to copyright.
Source publication
This manuscript proposes a unique topology ofswitched capacitor based multilevel inverter (MLI) that employs capacitors and DC sources as DC connections to generate staircase voltage waveforms. The use of DC sources is reduced in this MLI. Even with lower DC sources, the MLI is capable of generating 9 voltage levels. The novel MLI module produces 9...
Contexts in source publication
Context 1
... pencil-shaped switched capacitor (PSSC) MLI is designed following the structure of a pencil which is illustrated in Fig. 1. It consists of 3 major parts. The first part is called the head which is designated by the symbol h, the 2 nd part is called the body symbolized by b and the final part is known as the eraser and it is symbolized by ...
Context 2
... obtained simulation results from the previous section is validated in this section by building a prototype of the proposed PSSC MLI. The hardware model is build using a digital signal processor (DSP). The switching pulses are obtained following Table I and the NLC modulation technique. The prototype of the system is shown in Fig. ...
Context 3
... keep the results similar to the simulation results, each voltage level of PSSC MLI is considered to be 10 V. Hence, two 10 V DC supplies are used in the model. While using a single unit of PSSC MLI, the output voltage level was obtained to be 40 V as shown in Fig. 11(a). The harmonic spectrum is analyzed using power quality analyzer Fluke 43B and the result is shown in Fig. 11(b). It can be confirmed by comparing the harmonics of Fig. 8(b) and Fig. 9(b) that the results are highly similar. Although the THD from the experimental result is increased by a small margin, it still followed IEEE 519 ...
Context 4
... to the simulation results, each voltage level of PSSC MLI is considered to be 10 V. Hence, two 10 V DC supplies are used in the model. While using a single unit of PSSC MLI, the output voltage level was obtained to be 40 V as shown in Fig. 11(a). The harmonic spectrum is analyzed using power quality analyzer Fluke 43B and the result is shown in Fig. 11(b). It can be confirmed by comparing the harmonics of Fig. 8(b) and Fig. 9(b) that the results are highly similar. Although the THD from the experimental result is increased by a small margin, it still followed IEEE 519 standard. Thus, validating the accurate operation of PSSC MLI. The cascaded connection consisting of two units of PSSC ...
Similar publications
Transformerless grid-connected inverters have attained a lot of research interest in renewable energy interface applications, due to certain promising properties like greater efficiency, light weight, affordable price, and tolerable power density. Among various types of transformerless grid-tied photovoltaic (PV) inverters, multilevel inverters (ML...
Citations
... In [32], the same voltage levels are produced with a smaller number of switches. In [33][34][35][36][37][38][39][40][41][42][43], nine-level SC-based inverters have been introduced. In some SC-based topologies, the capacitors do not play a role to produce a reversed output voltage, and they are charged and discharged only for boosting purposes. ...
To proceed to a net zero carbon world and to mitigate the environmental challenges associated with it, integration speed of renewable energy sources such as photovoltaic (PV) systems has been increased around the world. Here, an improved switched‐capacitor based nine‐level inverter is introduced for PV applications. This topology has several benefits such as, voltage boosting feature, using a single DC source, reduction of capacitor charging current spike and extendable input voltage. This inverter produces nine‐level output voltage waveform using single power supply. This topology, using identical two capacitors in parallel with a single DC source, can boost the input voltage. In this inverter to limit spike current of capacitor charging mode, an inductor is placed in the charging path of capacitors with a parallel diode. The power losses and overall efficiency analysis of the improved inverter are considered. To verify the accurate performance of inverter under a step change on power flows, simulation results are obtained by MATLAB/Simulink software and presented. To highlight the benefits of the inverter, a comparison of improved topology with most recent topologies is performed. Finally, to verify the feasibility and performance of the improved inverter, experimental results of a 770 W grid‐tied prototype are presented.
... The inverter topology has self capacitor voltage balance capacity but lacks the boosting ability. Three nine-level SC-based inverters with a single source topology have been suggested in [9], [10], [18], in which capacitor voltage balance is performed without complicated circuits or auxiliary power. On the other hand, the voltage multiplication factor for them is two. ...
Multi-level inverters (MLIs) with switched capacitors are becoming popular due to their utilization in AC high-voltage applications as well as in the field of renewable energy. To achieve the required magnitude of output voltage, the switched capacitor (SC) technique employs a lesser number of DC sources in accordance with the voltage across the capacitor. Designing an efficient high-gain MLI with fewer sources and switches needs a rigorous effort. This paper introduces a prototype of a nine-level quadruple boost inverter (NQBI) topology powered by one solar photo-voltaic source using fewer capacitors, switches, and diodes when compared to the other SC-MLIs topology. The suggested NQB inverter produces nine levels of voltage in its output by efficiently balancing the voltages of the two capacitors. The various SC-MLIs are compared in order to highlight the benefits and drawbacks of the proposed nine-level quadruple boost inverter (NQBI) topology. To validate the efficacy of the proposed solar photovoltaic based NQBI without grid connection, detailed experimental results are presented in a laboratory setting under various test conditions.
... Besides, in some structures, they are exploited to augment the value of the input DC source. The main privilege of this type of inverters is controlling the voltage of the capacitors without any complicated algorithms [17][18][19][20]. The introduced switched-capacitor inverter in [21] provides 13 voltage levels at the output and utilises fewer number of components than the conventional structures [22,23]. ...
This study introduces a boost multilevel inverter (MLI) based on a switched capacitor structure. The proposed inverter features high modularity as a result of which more levels and ratings of voltage can be obtained in the inverter AC terminals. The extension of this topology in both symmetric and asymmetric configurations are introduced and analysed. Taking advantage of the switched‐capacitor technique, only one DC source is utilised while the voltages of several capacitors are kept balanced without the adoption of any sophisticated balancing algorithm. A combination of two basic submodules named as boost switched capacitor submodule and dual switched capacitor submodule forms the proposed structure. Compared to the existing alternatives, the proposed one provides more voltage levels with a lower number of power switches and input DC sources. The performance of the presented MLI is verified through the MATLAB/Simulink environment. Finally, the experimental results are presented, validating the feasibility and effectiveness of the studied inverter.
... Within this topology, a separate conduction path is provided to charge every capacitor equally using several switches, which increases the demand of semiconductor switches as well as the value of total standing voltage (TSV). Another switched capacitor topology proposed by the authors of [8] consists of comparatively lower number of switches than the topology in [7], but it suffers from high capacitor ripple losses problem. Furthermore, the switched capacitor inverter with alleviated number of switching devices proposed in [8] introduces high dv/dt stress voltages of the switches and an unsatisfactory amount of total harmonic distortion (THD) in current. ...
... Another switched capacitor topology proposed by the authors of [8] consists of comparatively lower number of switches than the topology in [7], but it suffers from high capacitor ripple losses problem. Furthermore, the switched capacitor inverter with alleviated number of switching devices proposed in [8] introduces high dv/dt stress voltages of the switches and an unsatisfactory amount of total harmonic distortion (THD) in current. ...
This paper presents a new hybrid multilevel inverter topology that offers several advantages such as reduced number of components, optimized costs, encapsulated size and light weight. The proposed compact cascaded inverter consists of six switches and three asymmetrical dc voltage sources that is able generate six positive voltage states, and multiple modules can be cascaded to generate a desired level of voltage. An H-bridge unit is connected between the load and the cascaded modules that helps to produce negative half cycle using the positive voltage states originated by the modules. Although the proposed compact cascaded inverter contains an H-bridge unit, it offers a moderate level of total standing voltage unlike the existing topologies, resulting in a decreased number of equipment and cost. A level shifted multi-carrier based PWM technique is used to drive the switches of the proposed inverter, which provides current with less total harmonic distortion (THD). Finally, the performance of the proposed compact cascaded inverter has been evaluated by the simulation tests carried out in MATLAB/Simulink and results presented. Index Terms-Multilevel inverter (MLI), total standing voltage (TSV), level shifted multi-carrier based PWM.
... That inverter however demands nine switches with at least four of them conducting simultaneously. The increases in switches are even more noticeable in [8] and [9] at a higher voltage level. It may therefore be more appealing to consider the variant in [10], where some switches and their gating circuits in [9] have been replaced by diodes. ...
... inverters [11]- [13]. It is however higher than those of the fivelevel inverters [7], [14], and nine-level inverters [8]- [10]. These compared MLIs nevertheless use more switches and hence more gating circuits. ...
Multilevel inverters in renewable applications usually require a high-voltage DC link fed by a front-end DC-DC boost stage. Such a two-stage power conversion however increases the switch count, leading to higher costs and power losses. To lower the number of switches, this letter proposes a six-switch inverter, capable of generating a seven-level voltage and a triple-voltage boost. Both features are achieved with only four switches operating at a high frequency, while clamped by low-voltage capacitors. The remaining two switches must however endure higher voltage stresses, but fortunately operate at a much lower frequency. Overall switching losses of the inverter are thus significantly reduced. Besides, the inverter shares a common ground between its DC input and AC output, which theoretically helps to eliminate leakage current, if powered by photovoltaic sources. Operating principles of the inverter have been described and verified through experiments with an 800-W prototype.
... Another topology based on the SC concept has been presented in [27], which generates nine levels at the output while employing 12 power semiconductor switches with a voltage gain of two. Furthermore, the topologies suggested in [28]- [30] requires a higher switch count. ...
... The proposed topologies [P1] and [P2] along with the topologies suggested in [25]- [28] gives the nine-level output voltage with twice voltage gain. The topology suggested in [27] requires three capacitors with 11 switches. ...
... Out of three capacitors, one has a voltage rating equal to the input voltage. The topology proposed in [28] uses the lowest number of switches for nine-level output voltage, however, the voltage stress of the switches have a higher voltage rating. ...
Multilevel inverter (MLI) topologies play a crucial role
in the dc-ac power conversion due to their high-quality
performance and efficiency. This paper aims to propose a new
switched-capacitor based boost multilevel inverter topology
(SCMLI). The proposed topology consists of nine power
semiconductor switches with one dc voltage source and two
capacitors, capable of generating a nine-level output voltage
waveform with twice voltage gain. Other features of the proposed
topology include self-voltage balancing of capacitors, parallel
operation of capacitors, lower voltage stress across the switches,
along with inherent polarity changing capability. To obtain the
high-quality output waveform, selective harmonic elimination
pulse width modulation (SHEPWM) technique is applied. In this
technique, the detrimental low-order harmonics can easily be
regulated and eliminated from the output voltage of MLI. The
proposed topology is compared with the recently introduced
SCMLI topologies considering various parameters to set the
benchmark of the proposed topology. The performance of the
proposed MLI is investigated through various experimental
results using a laboratory prototype setup.
... Different switched capacitor cell (SCC) Modules (a) presented in [12], (b) presented in [13], (c) presented in [15], (d) presented in [16] and (e) Proposed SCC Module. ...
... In this topology, the maximum voltage stress on the switch is equal to the input voltage as shown in Fig. 1 (c) and 9L inverter topologies with different switched capacitor cell (a) presented in [15], (b) presented in [16] and (c) Proposed circuit diagram. ...
... the corresponding structure is shown in Fig. 2(a). MLI with quadarable voltage boosting is presented in [16], [17]. The output voltage is four times higher than the v in . ...
In this letter, a new cross-connected compact
switched capacitor (C 3 SC) cell is introduced for multilevel
inverter applications. The proposed CCS cell uses four
switches and two diodes for interconnecting the input dc
source and floating capacitors (FCs). A nine-level inverter is
derived with the proposed C 2 SC cell requiring only ten
switches and two FCs. The proposed C 3 SC cell-based MLI is
self-balancing and has a voltage gain of two. All the switches of
the proposed topology have a maximum blocking voltage
within the input dc voltage (v in ) value. The operating principle
is detailed, and a simple logic gate based gate pulse generation
scheme is presented. Detailed simulations and experimental
results obtained from an 850 W prototype with several test
cases are presented to validate the operation of the proposed
topology. Finally, a detailed comparative assessment is
performed with other recent SCMLIs to demonstrate the
merits and superiority of the proposed topology.
... In recent years, the switched-capacitor based MLIs (SCMLIs) have gained tremendous popularity over other types of MLIs. The SCMLIs usually utilizes only one single DC source and several self-voltage balancing capacitors, which leads to less size, weight, cost, simple and easy control and also high voltage gain [7][8][9][10][11]. In SCMLIs with natural voltage balancing of capacitors, the capacitors can be charged by input DC source and at the same time be applied for producing desired voltage level [12]. ...
This article proposes a compact five-level common-ground-type inverter with inherent boosting capability. Due to
the common ground feature, the leakage current is eliminated,
making it suitable for solar photovoltaic applications. The distinctive features of the proposed inverter are that it employs two
switched capacitors rated for only half of the output voltage with
self-voltage balancing ability, which reduces the inverter’s size,
cost, and complexity. In addition, the proposed topology has the
lower component count, the lower total standing voltage, a low
dv/dt, lower number of conducting devices, and reduced capacitor
voltage diversity factor as compared to its counterparts. The
circuit description and operating principle are discussed in detail.
Furthermore, the proposed and state-of-the-art topologies are
compared to highlight their pros and cons. Further, a discussion
of additional features such as the cost and volume requirements,
addresses the usefulness of the proposed topology in practical
situations. Finally, experiential results are presented for grid-connected operation of the proposed topology, so as to validate
its feasibility.
