This treatise deals with Transistor Clamped Five Level Inverter using Non-Inverting Double Reference Single Carrier PWM (NIDRSC PWM) Technique. Conventional or two level inverter have drawbacks like: i) Requirement of fast switching devices, ii) Very high dv/dt, iii) High Electromagnetic Interferences (EMI), iv) Bulky filters, v) Faster heating of switches, and vi) Not suitable for high voltage applications. Multilevel Inverters (MLIs) are engaged to conquer the drawbacks of conventional two levels inverter. MLIs generate an AC voltage using small voltage steps obtained with the help of DC supplies or capacitor banks. To design the proposed five level inverter five numbers of power control switches and eight diodes are required. The proposed inverter circuitry is investigated by using Non-Inverting Double Reference Single Carrier PWM (NIDRSC PWM) Technique in terms of harmonics content in output waveform. Under-modulation (modulation Index = 0.85), unity (modulation Index =1) and over-modulation (modulation Index = 1.25) PWM signal is obtained to drive control switches. Simulation results will confirm the functionality, design and operation of the proposed MLI and NIDRSC PWM Technique.

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Transistor Clamped Five-Level Inverter using Non-Inverting Double Reference Single Carrier PWM Technique for photovoltaic applications

The Multilevel inverters (MLIs) are a new breed of power electronics converters. They are primarily used for the conversion of dc power to ac power. The two-level inverters are conventionally used to obtain ac power, but it requires operating the switches under very high switching frequency. Besides, the two-level inverter necessitates the use of LC filters with the switches operating under high dv/dt stress. The MLIs offer the advantage of utilizing several dc voltage sources to generate a stepped ac waveform with the proper arrangement of switches. Investigation of a Transistor Clamped T Type H-Bridge Multilevel Inverter (TC-TT-HB-MLI) with Inverted Double Reference Single Carrier PWM Technique (IDRSCPWM) for Renewable Energy Applications are discussed in this paper. A PV source is taken as an input to the TC-TT-HB-MLI. For different modulation indices like 0.85, 1 and 1.25, the FFT analysis is performed and presented, which corresponds to the variations in the irradiations from solar energy. A single unit of the TC-TT-HB-MLI is extended to a generalized MLI structure named Generalized Transistor Clamped T-Type H-Bridge Multilevel Inverter (GTC-TT-HB-MLI). The significant benefits of GTC-TT-HB-MLI are the multiple numbers of reductions in the switch count, and driver circuit counts for a higher number of MLI levels. Fast Fourier Transform (FFT) analysis is carried out on the MLI output to calculate the total harmonics distortion (THD). The experimental verification is performed using SPARTAN 3E-XCS250E; the gate signals are generated and provided to the switches.

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Investigation of a Transistor Clamped T-Type Multilevel H-Bridge Inverter With Inverted Double Reference Single Carrier PWM Technique for Renewable Energy Applications.

This paper presents a simplified sinusoidal pulse width modulation (SSPWM) proposed to control a half-bridge multilevel inverter. This topology has less number of switching components compared to conventional types of multilevel inverter. It can be supplied from separated dc sources or renewable energy sources like solar energy via photovoltaic modules. This topology can be a symmetric or an asymmetric inverter via controlling the magnitude of dc sources. The asymmetric choice provides higher number of levels with less number of switches and dc sources. The proposed technique is a high switching frequency modulation based on the sinusoidal pulse width modulation. The SSPWM can be achieved using only one modulating, carrier signals and throughout a certain logic arrangement depends on number of levels. A laboratory system was built based upon the (NI PCI-6013) data acquisition controller and experimental results for single phase fifteen-level inverter show a well-matching and good similarity with the simulation results.

Simplified sinusoidal pulse width modulation for cascaded half-bridge multilevel inverter

In this article 2.4 kW, three-phase inverter for aircraft application is articulated. When aircraft above 1000 m altitude, power amplifiers are employed to increase the strength of signal during transmission. The circuitry consist of input filter, three-phase output obtained by connecting three single-phase H-bridge inverter, transformers and LC filters at the star connected load end. The (THD) of proposed three-phase inverter is 2.8%. The Total Harmonics Distortion (THD) of the circuit is reduced by using sinusoidal pulse width modulation technique (SPWM). The component size is reduced by using high frequency modulating signal (400 Hz). The proposed circuit performance is verified with experimental and simulation result. The experimental and simulation result confirms the feasibility of proposed converter.

2.4 kW Three-Phase Inverter for Aircraft Application-Hardware Implementation

This paper presents the design of a new single-Phase 9- and 17-level inverters with sinking the components. The 17-level inverter topology is designed by cascading the two nine-step inverters. The topology produces the complex number of output voltage levels with high reliability and reduced total harmonic distortion. We develop numerical modeling of the converters using MATLAB/Simulink block sets, and we realize experimental prototype in a laboratory-scale model using digital processor dSPACE RTI 1104. Set of experimental and numerical results are provided in this paperwork to ensure and validate the feasibility as per IEC standards. Proposed inverters are well apt for low/high voltage renewable and hybrid electric vehicle applications.

A Novel Nine and Seventeen-Step Multilevel Inverters with Condensed Switch Count

Multilevel inverters (MLI) plays a vital role in high voltage and high power applications due to its capability of converting DC to AC with reduced total harmonics distortion (THD). In this paper, a new multilevel inverter (MLI) with fewer number of control switches is proposed. The proposed topology requires a fewer number of control switches compared to conventional and recently derived topologies, thereby reducing complexity and the total cost of circuit. The topology operation is discussed for a seven-level and it can be easily extended to N-level by adding (N-3)/4 repeating stages. N-level proposed topology requires (N+3)/2 unidirectional power switches and 2N-2 diodes. The proposed topology is simulated for 100W; seven levels with level shifting SPWM technique in MATLAB/SIMULINK and results shows the validity of topology.

A new multilevel inverter with fewer number of control switches

A multilevel inverter (MLI) is a popular inverter for solar based high power applications. The drawback of conventional H-bridge inverter is non-sinusoidal output voltage, which reduces the output quality of inverter. Later, the drawback of conventional Hbridge was overcome by conventional MLI. But, conventional MLI needs maximum number of diodes and switches. In order to overcome this drawback proposed MLI topology with level shifting sinusoidal pulse width modulation (SPWM) technique can be employed. Proposed MLI contain fewer number of switches and diodes, which helps in optimizing the circuit layout, reducing gate driver circuit for those switches. SPWM technique uses multicarrier waveforms with level shifting ensuring the reduction in total harmonics distortion (THD). In this Paper level shifting SPWM technique has been incorporated in which 5 kHz carrier wave is compare with 50Hz of sinusoidal wave with a modulation index of 0.8. THD of proposed 9-level inverter is 17.27% without filter and 4.29% with LC filter. Simulation of proposed inverter is carried out in MATLAB/SIMULINK.

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Multilevel inverter with level shifting spwm technique using fewer number of switches for solar applications

In this paper, A PV fed serial magnetic coupling and voltage multiplier cell Modified SEPIC converter by using P&O controlled algorithm is proposed. Using the serial magnetic coupling the voltage gain of the converter is elevated which provides the needed voltage for injecting PV to AC grid. The serial magnetic coupling with voltage multiplier cell converter can increase further by adding a number of voltage multiplier stages as per requirement of static gain. The MATLAB simulation model is developed with PV MPPT fed serial magnetic coupling and voltage multiplier cell. The result shows the proposed topologies of converters reduced switch voltage, reduces output diode voltage, reduces the reverse recovery current. With the proposed topologies the static gain of the converter is increased, as well as the efficiency of converter is increased up to about 92%

Ruchita Maheshwari

Papers

A new multilevel inverter with fewer number of control switches

Multilevel inverter with level shifting spwm technique using fewer number of switches for solar applications

Serial magnetic coupling and voltage multiplier cell modified SEPIC converter with elevated gain for solar application