Switched-capacitor Inverter Research Articles

A single phase nine level common ground switched capacitor inverter with double boosting capability

AbstractThis article suggests a nine‐level (9L) seven‐switch (7S) transformer‐less (TL) common‐ground (CG) switched capacitor (SC) inverter with double boosting capability. The proposed 9L7S‐CGSC‐TL inverter comprises only seven switches (7S), two diodes, three self‐balanced capacitors, and one DC source. The suggested inverter has a CG connection which eliminates ground leakage currents. Additionally, the suggested topology necessitates fewer conducting devices, thereby reducing conduction losses. The voltage across every capacitor is automatically balanced within each fundamental cycle. The proposed topology has been evaluated based on parameters such as component count, total harmonic distortion, cost, and efficiency. The proposed configuration switching sequence is governed by employing the level‐shifted pulse width modulation technique. A power loss study was conducted to determine the efficiency of the proposed switched capacitor multilevel inverter (SCMLI) under different load conditions in PLECS. The results shows that the proposed SCMLI achieves a peak efficiency of 98.17%. Further, the lifespan of the proposed SCMLI is assessed through a reliability assessment. The simulation and experimental results at different conditions are presented and elucidated.

Research on a Thirteen-Level Switched Capacitor Inverter with Low Switching Loss

This paper presents a 13-level switched capacitor inverter with a novel modulation method designed to minimize the number of switches and significantly reduce switching losses. The inverter stands out for its simplicity, requiring only ten semiconductor switches to generate 13 levels. A key feature is the inherent self-voltage balancing of the capacitors, which eliminates the need for additional control mechanisms. The inverter’s unique architecture, comprising high-voltage and low-voltage modules, enables modulation using a hybrid PWM approach that combines step waveform modulation with level-shifted PWM (LS-PWM). This innovative technique dramatically lowers the switching frequency of the high-voltage module’s switches, independent of the carrier frequency, thereby limiting the number of switches in high-frequency operation and achieving substantial reductions in switching losses. This paper provides a detailed analysis of the inverter’s operating modes, voltage-balancing mechanisms, and parameter calculations. The advantages of the topology presented in this paper are demonstrated by comparison. Finally, the simulation and experimental results confirm the practicality and effectiveness of the proposed inverter and its modulation strategy.

Advanced energy management scheme for fuel cell-based microgrid using self–regulated controller and switched capacitor inverter

Clean energy production is now the main challenge for sustainable future which can be addressed by introducing renewable energy sources. Fuel cells are critical in providing sustainable energy solutions by enabling efficient energy conversion in microgrids. To enhance the performance of fuel cell-based microgrids, advanced controllers and inverters are necessary to manage power quality and stability. One of the key benefits of this fuel cell is the separation of energy conversion and management, which allows independent optimization for each function of microgrid's performance, cost, or other installation considerations. The ability to individually control of each component of a microgrid can significantly impact various applications positively. Beyond their technological and economic advantages, fuel cells are highly sensitivity to microgrid's characteristics such as current quality and harmonics which creates difficulties for their design and management. Therefore, the entire microgrid must be managed by an effective energy management strategy and integration of advanced inverter topologies. This study aims to improve fuel cell efficiency and power quality within the microgrid through an advanced energy management (AEM) strategy. The proposed AEM structure is developed focusing on two key components: a self-regulated controller (SRC) and a switched capacitor multilevel inverter (SCMLI). These elements work together to mitigate the disturbances and enhance the power quality of the system. The methodology includes simulation and hardware-in-the-loop (HIL) testing under non-linear load conditions. Initial grid-side current total harmonic distortion (THD) of 28.38% was reduced to 2.19% through the proposed system. An impact analysis is also presented to demonstrates that reducing current harmonics and voltage imbalance have improved the efficiency of fuel cell to 50.18% and fuel utilization to 98.05%. The findings show that the proposed scheme significantly reduces current harmonics and improves the overall performance benchmark of the microgrid and fuel cell.

An Inductorless Triple Boost 13-Level Switched Capacitor Inverter With Reduced Ripple Current

An Inductorless Triple Boost 13-Level Switched Capacitor Inverter With Reduced Ripple Current

An enhanced 13‐level triple voltage gain switched capacitor inverter with lower power electronics devices

AbstractIn this study, a 13‐level switched‐capacitor inverter with triple voltage gain is proposed. The proposed structure generates 13‐level output voltage using only one DC source, eleven switches, and three capacitors. The capacitors have the capability of self‐balancing without the use of additional circuits or complex control methods. Additionally, the inrush current of the capacitors has been reduced using a soft charging method. The proposed structure has been compared with different 13‐level structures presented in recent studies in terms of various parameters such as the number of semiconductor devices, the number of DC sources, voltage gain, Maximum Blocking Voltage (MBV), and Total standing Voltage (TSV). Another advantage of the proposed structure is the non‐use of any diode and its cost‐effectiveness. In addition, the power losses of the proposed structure have been evaluated, and its efficiency has been calculated for various output powers. Finally, the performance of the proposed structure has been verified through simulation and laboratory implementation under both stable and various dynamic conditions.

A 17-level octuple boost switched-capacitor inverter with lower voltage stress on devices

This paper presents a new structure for switched-capacitor multilevel inverter with octuple voltage gain capability. The proposed inverter utilizes three capacitors, 13 semiconductor switches, three diodes, and an input voltage source to achieve a 17-level output voltage. The switched capacitors naturally achieve voltage balancing without the need for sensors or additional circuits, indicating the ease of control of the proposed structure. To control the inrush current of the switched capacitors, a charge limiting inductor has been utilized in the charging path of the capacitors. This not only reduces the inrush current of the capacitors and the input source current but also enables faster capacitor charging and extends their lifetime. The switches used in the proposed structure can withstand a maximum of 4 times the input voltage value or the half of the maximum output voltage, which is a significant advantage for the proposed structure. A detailed comparison with similar structures is provided to examine the advantages and disadvantages of the suggested inverter. The procedure of self-voltage balancing of the capacitors and the functional modes of the proposed topology has been explained in detail. The proposed structure is suitable for applications such as renewable energy sources transfer to load or grid. The performance of the proposed topology under different conditions is confirmed through simulation in the Matlab\\Simulink software and the implementation of the laboratory sample.

Switched Capacitor Inverter with Reduced Inrush Current and High Boosting Gain

Switched Capacitor Inverter with Reduced Inrush Current and High Boosting Gain

RSO based selective harmonic elimination control for nine-level switched capacitor inverter

Abstract Renewable energy utilization has gained much attention in the recent time owing to the sharp increase in the power demand. Out of different renewable sources, photovoltaic (PV) energy utilization in different forms is one of key focus. Power converter such as multilevel inverters (MLIs) are proven as key components for PV systems as well as for other applications such as motor drives, electric vehicles, and charging stations. With the advancement of the design of MLIs, the switched-capacitor (SC) based MLIs have been widely deployed for their boosting capability which is a major requirement for PV systems. In this paper, a reduced switch single input step-up 9-level SC MLI is first proposed. Followed by this, a new Rat Swarm Optimization (RSO) based Selective Harmonic Elimination (SHE) control method is incorporated for switching operation. RSO has the ability to provide the solution with higher competency within less time and a less computationally complex approach. The operation of proposed structure is analyzed and its advantages are justified by comparison with exiting topologies. The effectiveness of RSO based SHE scheme is also verified by comparing it with other nature-inspired algorithms. The effectiveness and workability of the proposed system are examined using simulation and experimental tests.

High-Performance Multi-Level Inverter with Symmetry and Simplification.

This paper presents a high-performance, multilevel inverter with symmetry and simplification. This inverter is a single-phase, seven-level symmetric switched-capacitor inverter based on the concept of the double voltage clamping circuit connected to the half-bridge circuit. Above all, only a single DC power supply is used to achieve a single-phase inverter with seven levels and a voltage gain of three. In addition to analyzing the operating principle of the proposed switched-capacitor multilevel inverter in detail, the stability analysis and controller design are carried out by the state-space averaging method. The feasibility and effectiveness of the proposed structure are validated by some simulated results based on the PSIM simulation tool and by some experiments using FPGA as a control kernel, respectively. However, in this study, the switches were implemented by MOSFETs to meet a high switching frequency. These MOSFETs can be replaced by IGBTs in the motor drive applications so that the used switching frequency can be reduced.

A Novel Leg-Integrated Switched Capacitor Inverter Topology for Three-Phase Induction Motor Drives

This paper presents an optimized leg-integrated switched capacitor inverter (LISCI) topology for 3-φ induction motor driven home appliance applications where a switched capacitor (SC) network, used for voltage boosting, is integrated with one of the inverter legs (phase-A leg). This results in a reduced semiconductor requirement as the voltage ratings of the phase-A switches are reduced by half. Moreover, due to the unique structure of the proposed topology, it can produce 3-level pole voltage corresponding to phase-A, even though the pole voltages of phases B and C remain 2-level. This kind of performance, referred to as quasi 3-level performance, results in an unusual space vector (SV) hexagon with 12 SVs, which is implemented by using a novel PWM method. A comparison study of the proposed topology with the existing SC based 3-φ inverter topologies reveals that the former has the lowest semiconductor requirement, highly improved harmonic performance and very low losses. All the claims are supported by experimental validations performed on a 3φ induction motor (3φIM) drive.

A Self Tuning Fuzzy Control Based Dual Input Nine-Level Self Balancing Switched-Capacitor Inverter for Induction Heating Applications

A Self Tuning Fuzzy Control Based Dual Input Nine-Level Self Balancing Switched-Capacitor Inverter for Induction Heating Applications

A 17-level quadruple boost switched-capacitor inverter with reduced devices and limited charge current

In this paper, a quadruple boost switched-capacitor multi-level inverter is proposed. The proposed structure utilizes a DC source, 11 switches, and a diode to achieve 17-level output voltage levels. This structure consists of three capacitors with the ability for self-balancing voltages. The capacitors achieve automatic voltage balancing through a series/parallel connection with the input voltage source. To control the switching pulses of the switches, level-shifted pulse width modulation (LS-PWM) strategy has been employed. A comparative evaluation has been performed between the proposed structure and structures presented in recent articles, considering various parameters such as voltage gain, number of DC sources, number of semiconductor devices, maximum blocking voltage (MBV), and total standing voltage (TSV). Considering this comparison, the lower number of semiconductor devices for generating a 17-level output with suitable voltage gain, and especially the cost-effectiveness of the structure, are the main advantages of the proposed configuration. In addition, a soft charging method has been employed to limit the inrush current of capacitors. Moreover, the power losses of the proposed structure have been investigated, indicating its acceptable efficiency. Finally, for the analysis and validation of the proposed structure's performance, an experimental prototype has been implemented and evaluated under various conditions. The results indicate satisfactory performance of the proposed structure under various stable and dynamic operating conditions.

Nine level switched capacitor inverter with level shifted pulse width modulation approach

This article proposes a nine-level switched capacitor inverter (NLSCI) with a minimum number of switches. In recent years, switching capacitor (SC) multilevel inverters (MLIs) have become one of the most common inverter topologies. These proposed nine level switched capacitor inverter (NLSCI) do not deserve any external control unit for capacitor control. Since, the charging and discharging of the capacitors are controlled by the on and off states of switches. Furthermore, by employing fewer switches and DC voltage sources, the suggested design produces a greater amount of resultant voltage. Additionally, pulse width modulation (PWM) is recommended as a method to enhance output quality and power level quality. The switched-capacitor two-output multilevel inverter (SCMLI) structure's viability and effectiveness have been demonstrated using MATLAB simulation.

Optimized 9-Level Switched-Capacitor Inverter for Grid-Connected Photovoltaic Systems

Optimized 9-Level Switched-Capacitor Inverter for Grid-Connected Photovoltaic Systems

A Reduced Component Count Self-Balance Quadruple Boost Seventeen-Level Switched Capacitor Inverter

A Reduced Component Count Self-Balance Quadruple Boost Seventeen-Level Switched Capacitor Inverter

Seven‐level single‐source switched capacitor inverter with triple boosting capability and high reliability

SummaryA single‐source switched capacitor multilevel inverter (SCMLI) topology utilizing only 10 switches and 1 diode with the capability of generating seven output voltage levels and a triple voltage boosting factor is proposed in this paper. The converter has capacitors that are self‐balanced and do not require any additional circuitry. The multicarrier sinusoidal pulse width modulation (PWM) technique is used to generate various switching signals for the 10 switches. Moreover, the reliability analysis using the Markov model has been carried out to assess the lifespan of power electronic components used in the proposed converter. The converter's performance is analyzed when an open circuit fault occurs in one or multiple switches. Power loss and efficiency in the converter are calculated by PLECS software using thermal modeling. The efficiency of SCMLI was found to be 97.6% for a 300 W load. The inverter working is verified by building a 500 W prototype in the lab. The experimental results in steady‐state and dynamic conditions agree with the theoretical and simulation analysis.

A Single Phase Five Level Switched Capacitor Inverter With Common Ground Configuration

A Single Phase Five Level Switched Capacitor Inverter With Common Ground Configuration

A Single Source Quadruple Boost Nine-Level Switched-Capacitor Inverter with Reduced Components and Continuous Input Current

A Single Source Quadruple Boost Nine-Level Switched-Capacitor Inverter with Reduced Components and Continuous Input Current

Design and Implementation of Transformer-less Common-Ground Inverter With Reduced Components

Nowadays, common-ground-type (CGT) based transformer-less inverters (TIs) are gaining more popularity in photovoltaic (PV) applications owing to their low cost, weight of the systems, losses and zero ground leakage current. For PV applications, a separate boost converter is often used to boost the low PV array voltage, resulting in increased component count, cost and lower efficiency. To resolve this issue, switched-capacitor (SC) based CGT inverter with reduced component count is proposed in this paper. The proposed amalgamation of CGT and SC technique, results in inherent boosting and zero ground leakage current. In the proposed inverter, SCs are connected in series/parallel with the dc voltage source for several instances in a fundamental cycle preserving the self-voltage balancing ability. Therefore, the proposed topology is devoid of voltage sensors to balance the voltage across SCs. Further, A simplified logic gatebased pulse-width-modulation strategy is developed. In addition, the benefits of proposed inverter are highlighted and compared with the other recent SC inverter topologies with regard to boosted voltage, elimination of leakage current and reduced component count. A laboratory prototype is developed by using DS1202/1302 dSPACE controller and experimental results are presented for both steady state and dynamic conditions and verifying the feasibility of the proposed TI.

A New 5L SC-Based Boosting Inverter with Reduced Spike Current

The drawbacks of conventional multi-level inverters (MLIs) include insufficient boost capacity, unbalanced capacitor voltage, and complicated regulation. This research presents a 5-level (5-L) switched capacitor (SC) boost inverter for single-phase applications as a solution to the aforementioned problems. The 5-L inverter is well-suited for renewable energy generation since it can produce five output levels with two voltage gains and maintain a natural balance in capacitor voltages with only seven switches. However, the SC inverter’s large current spikes could harm capacitors, switches, and DC sources. The suggested inverter’s charging loop incorporates an inductor to mitigate this issue by smoothing out voltage fluctuations and current spikes. The simulation and experiment findings presented here prove that the proposed system works and performs as expected.