Single Phase Hybrid Multilevel Inverter Research Articles

Hybrid multilevel inverter using switched capacitor with boosting and self-balancing capability

Switched capacitor based multilevel inverters with boosting capability are emerging as single stage DC–AC conversion in utilizing low voltage DC sources such as solar PV and fuel cell. This paper proposes a single-phase hybrid multilevel inverter topology based on a switched capacitor that is capable of generating 9-levels along with a voltage gain of 2. The components required to construct the basic module of topology are 11 switches, 1 diode and 2 capacitors. The voltage balancing of the switched capacitors is achieved with the help of a modulation strategy, thereby eliminating the need of sensors. The theoretical loss analysis of the inverter is presented and the nearest level control based fundamental switching frequency modulation technique is employed to study the performance of the proposed inverter. The effectiveness of the suggested topology is validated with the help of a prototype built in the laboratory. The superiority of the proposed topology is assessed with the help of comparison with existing topologies.

A high‐gain IΓ‐source hybrid single‐phase multilevel inverter for photovoltaic application

Impedance-based step-up converters are widely developed for photovoltaic applications due to providing single-stage conversion, high-efficiency, low voltage and current stresses, and high boost-factor. An improved Γ-source (IΓ-source) single-phase hybrid multilevel inverter is proposed. This structure has a better voltage gain characteristic, high-efficiency, multilevel output voltage, low output current total harmonic distortion (THD), and continuous input current. It is extensible for attaining higher voltage levels. Furthermore, higher non-shoot-through modulation indexes are obtainable by this topology in comparison with previous works due to performing higher gains in lower shoot-through duty cycles. Also, the output harmonics are reduced because of applying lower shoot-through duty cycles. This article demonstrates the operating principle of this hybrid multilevel inverter in detail. Simulation and experimental results are exhibited to evaluate the performance of this converter. Results confirm the proposed IΓ-source hybrid multilevel inverter, its operating principle, and the modulation strategy.

A New Hybrid Multilevel Inverter Topology with Reduced Switch Count and dc Voltage Sources

In this paper, a new single-phase hybrid multilevel inverter (MLI) is proposed. Compared to other existing MLI topologies, the proposed circuit is capable of producing a higher number of output voltage levels using fewer power switches and dc sources. The levels are synthesized by switching the dc voltage sources in series/parallel combinations. An auxiliary circuit is introduced to double the number of levels by creating an intermediate step in between two levels. In addition, a zero level is introduced to overcome the inherent absence of this level in the original circuit. To improve the total harmonic distortion, a hybrid modulation technique is utilized. The operation and performance of the circuit are analyzed and confirmed using MATLAB/Simulink simulation. To validate the workability of the proposed idea, a 300 W, a thirteen level MLI (including the zero level) is designed and constructed. The circuit is tested with a no-load, resistive load and resistive-inductive load. The experimental results match very closely with the simulation and mathematical analysis.

Solar powered hybrid multilevel inverter fed induction motor using fuzzy proportional integral speed controller

In this paper, speed control of solar powered single phase hybrid multilevel inverter fed induction motor using fuzzy proportional integral controller is proposed. The proposed control system has been developed using MATLAB/SIMULINK. Performance of the proposed controller is tested in reference speed conditions with step change. The parameter analyzed for the proposed controller is steady-state error and settling time. This is compared with the proportional integral controller. Proposed speed controller is tested with two speed region such as low speed region and high speed region. In low speed region, speed command is varied from 40, 60, and 80 rad/s with 0.6 s step time. In high speed region, speed command is varied from 100, 120, and 140 rad/s with 0.6 s step time. Corresponding, performance parameters are measured and analyzed for both regions with proposed controller and proportional integral controller. From the test results, fuzzy proportional integral speed controlled hybrid multilevel inverter fed induction motor outperforms than proportional integral controller. Finally, the results are verified experimentally.

Single‐phase multilevel inverter topologies with self‐voltage balancing capabilities

In this study, two new structures of single-phase hybrid multilevel inverter are proposed for both symmetrical and asymmetrical configurations that can be employed in drives and control of electrical machines and connection of renewable energy sources. The proposed configuration uses a less number of semiconductor devices and DC sources as compared with conventional and newly developed topologies which lead to a reduction in cost and installation area. The proposed topology poses a vital advantage of self-voltage balancing of its capacitor voltage regardless of load type, load dynamics and modulation index. Also, the proposed topology is expanded in a cascaded fashion which reduces the complexity and improves the performance significantly. A wide range of comparison is done with conventional and newly developed topologies to show the superior performance of proposed topologies regarding a total number of switches and DC sources. The multi-carrier pulse-width modulation strategy is adopted for generating switching pulses for respective switches. A laboratory prototype is developed for testing the performance of the proposed topology for 9-level and 17-level inverters.

Performance Evaluation of Multicarrier Based Techniques for Single Phase Hybrid Multilevel Inverter using Reduced Switches

The multilevel inverters are very popular in high power high voltage applications. However the multilevel inverters has some demerits such as requiring higher number of components, PWM control method is complex and capacitor voltage balancing problem. The hybrid multilevel inverter presented in this paper has superior characteristics over conventional multilevel inverters. The hybrid multilevel inverter employs fewer components and less carrier signals when compared to conventional multilevel inverters. It consists of level generation and polarity generation stages which involves high frequency and low frequency switches. The complexity and overall cost for higher output voltage levels are greatly reduced. Implementation of single phase 7-level, 9-level and 11-level hybrid multilevel inverter has been performed using sinusoidal pulse width modulation (SPWM) strategies i.e., phase disposition (PD), alternate phase opposition disposition (APOD) and carrier overlapping (CO). Also the three techniques are compared in terms of total harmonic distortion (THD) for various modulation indices and observed to be greatly improved when compared to conventional topologies. The performance of single phase eleven level hybrid inverter is analyzed for different loads. Simulation is performed using MATLAB/ Simulink.

Performance Evaluation of Multicarrier Based Techniques for Single Phase Hybrid Multilevel Inverter using Reduced Switches

Performance Evaluation of Multicarrier Based Techniques for Single Phase Hybrid Multilevel Inverter using Reduced Switches

A Single Phase Grid Connected Hybrid Multilevel Inverter for Interfacing Photo-voltaic System

Abstract This paper introduces a new single phase hybrid multilevel inverter with a minimum number of switches for a Photovoltaic application. A Perturb and observe maximum power point tracking is used for tracking maximum power from solar panel. A boost converter is used for boosting the generated voltage because proposed inverter operates at the asymmetric condition. The proposed inverter is the combination of reduced switch topology and cascaded H-Bridge topology. Two types of Phase Disposition carrier arrangement with sinusoidal reference is utilized for generating the gating pulses for proposed inverter. It generates a 15-level output voltage with 8.12% of total harmonic distortion.