Single Stage Dual Boost Inverter with Half Cycle Modulation Scheme for PV System Applications

In this paper a new control method is presented for a switched capacitor-quasi switched boost inverter (SC-qSBI). The proposed control is based on a combination of phase shift and PWM. This method increases the voltage gain and provides soft-switching conditions for the switches. The voltage gain of this inverter is flexible due to using a phase shift in the controller. The SC-qSBI has major features such as the common ground between dc input and ac output voltage, and shoot-through (ST) mode to electromagnetic interface (EMI) immunity. Moreover, a high ac output voltage is generated without adding extra elements. The switching algorithm, operating principle, and steady-state analysis of the inverter are presented. Finally, the simulation result validates the theoretical analysis.

The paper introduces a Non-Ideal Boost Inverter with Linear Load as an alternative to the traditional Voltage Source Inverter. Unlike the traditional inverter, this new design is capable of generating a sinusoidal AC output voltage that can be either higher or lower than the DC input voltage, depending on the duty cycle. This eliminates the need for a second power conversion stage. To enhance the performance of the Boost Inverter, a Sliding-PI controller, a relatively new control topology, is employed. The Kp and Ki constants for the controller are determined using a Genetic Algorithm. The paper then proceeds to present the operations, analysis, control strategy, and simulation results of the proposed inverter design.

In the conventional DC-AC inverter consisting of two DC-DC converters with unipolar output capacitors, the output capacitor voltages of the DC-DC converters must be higher than the DC input voltage. To overcome this weakness, this paper proposes a single-phase DC-AC inverter consisting of two embedded Z-source converters with bipolar output capacitors. The proposed inverter is composed of two embedded Z-source converters with a common DC source and output AC load. Though the output capacitor voltages of the converters are relatively low compared to those of a conventional inverter, an equivalent level of AC output voltages can be obtained. Moreover, by controlling the output capacitor voltages asymmetrically, the AC output voltage of the proposed inverter can be higher than the DC input voltage. To verify the validity of the proposed inverter, experiments were performed with a DC source voltage of 38 V. By controlling the output capacitor voltages of the converters symmetrically or asymmetrically, the proposed inverter can produce sinusoidal AC output voltages. The experiments show that efficiencies of up to 95% and 97% can be achieved with the proposed inverter using symmetric and asymmetric control, respectively.

Alternative energy systems (AES) are becoming popular for small scale power generation. Designing the converters which transform the DC power into AC is the main development area of AES. Conventional single-phase voltage source inverter (VSI) uses buck topology which gives lower average output voltage than the input DC voltage. However, where the output voltage requirement is larger than the input DC voltage, such as uninterruptible power supply, fuel cell (FC) and photovoltaic systems, boost inverters are used. The boost inverter applied in this study consists of two boost DC-DC converters, which provides sinusoidal AC voltage output. The key drawback of the inverter lies in its control structure. In this paper, a dual loop control method is applied to ensure pure sinusoidal output voltage with fast dynamic response and low input current ripple. The input voltage of the inverter is assumed to be stable at 48 V considering commercially available FC voltage and the output voltage is regulated at 110 Vrms. In this article, the operating principle, mathematical modelling, analysis and control strategy of the boost inverter is presented. The proposed control strategy is verified with simulation using MATLAB/Simulink®. Simulation results show that the output voltage is 110 Vrms pure sinusoidal and the input current has low ripples.

This paper compares the efficiencies of insulated gate bipolar transistor-based voltage and current source inverters. Test circuits that replicate the functionality of a single switching pole of each converter topology are used to measure the switching trajectories and loss characteristics of the semiconductor devices. These results are then used to simulate the losses for complete 3-phase voltage and current source inverters. Switching losses are shown to be dominant in the voltage source inverter whilst conduction loss is dominant in the current source inverter. It is shown that neither power converter operates more efficiently than the other over the complete operating range, with an equivalently rated voltage source inverter being preferable at lower power levels and the current source inverter being more efficient at higher power levels. (6 pages)

A novel single-stage half-bridge series-resonant buck-boost inverter (HB-SRBBI) is proposed. The main attribute of the novel inverter topology is the fact that it generates an ac output voltage larger or lower than the dc input one, depending on the instantaneous duty cycle. This property is not found in the classical voltage source inverter (VST), which produces an ac output instantaneous voltage always lower than the dc input voltage. The proposed inverter circuit topology provides the main switch for turn-on at zero-current-switching (ZCS) by an auxiliary resonant cell built before the output choke. A state-space averaging approach is employed to analyze the system. A design example of 500 W ac/dc inverter is examined to assess the inverter performance and it provides high power efficiency above 90.7% under the rated power.

In this paper it is presented a new integrated power conditioner topology proposed for a fuel cell based on power supply system. The proposed converter combines the conventional ZVS active clamp full bridge boost converter structure with the sinusoidal pulse width modulation technique to guarantee a sinusoidal output voltage. Particularly, the proposed fuel cell power conditioner is intended for stand-alone AC power generation and low voltage fuel cell input. The main characteristic of the proposed topology is the use of fewer components when compared to the conventional two-stage power conditioners approach reducing the cost. In addition, the total efficiency is increased by reducing the power processing stages. Therefore, it is expected that the proposed integrated power conditioner topology could be effectively utilized for fuel cells applications. It is also presented a compressive analysis of the main characteristics of the fuel cell which will determine the design parameters for the power conditioner. In order to validate the proposed approach, simulation and experimental results are provided for a 100 W integrated power conditioner prototype with 120 V ac output voltage and 26 V dc input voltage.

A Dual boost inverter for open-end winding induction motor has been used to improve the power of the induction motor and reduce the number of power switches. However, this configuration still has many disadvantages: the ac output voltage is less than dc input voltage and switches on the same leg turn on at the same time must be avoided. To solve this problem, this paper presents a dual inverter combine boost converter qSBI for open-end winding induction motor configuration that is used for low energies such as solar energy, fuel cell, and battery. With the proposed configuration, the ac output is higher than the dc input without a DC-DC converter and the switches on the same leg can turn on at the same time. Simulation and experimental results will be presented to demonstrate the new features.

This paper aims to present a PFCC (Power Factor correction converter) fed permanent magnet brushless direct current motor (PMBLDCM) drive for fan application with improved power quality in a supply network with reduced voltage stress of the switch and improved efficiency. It is a single switch single-stage topology and combination of boost and zeta PFCC. Both the converters are designed in discontinuous conduction mode (DCM) of operation, considering less switch stress. The fan speed is controlled by controlling the DC link voltage of the PFCC, and a simple voltage follower control technique is utilized to get the inherent PFC at the input supply. The DC link voltage sensor is eliminated by using an auxiliary winding voltage (V awg ) to control PFCC output voltage (VDC) and achieve the fan's variable speed. These techniques make an overall system cost-effective and straightforward with less harmonic distortion. Moreover, to achieve the electronic commutation, Hall Effect sensors are utilized, and the voltage source inverter (VSI) is switched at a fundamental frequency, which provides less switching losses in VSI. The BLDCM fan's performance is simulated in a MATLAB environment, and its behavior is given to confirm the design. This topology's power quality performance is found to adhere to the international harmonic standard IEC61000-3-2 for the universal RMS input supply.

This paper addresses the issues of switching behavior of a high power insulated gate bipolar transistor (IGBT) that works in hard switching conditions. First, the voltage and current switching waveforms of IGBT modules are described for an IGBT phase-leg module with an inductive load, and the associated switching losses, reverse recovery current of free-wheeling diodes, voltage overshoot, and EMI noise are analyzed. Based on the analysis, an actively controlled gate drive circuit is proposed, which provides optimization of the fast driving for low switching losses and short switching time, and slow driving for low noise and switching stress. Compared to a conventional gate drive strategy, the proposed active gate driver (AGD) has the capability of reducing the switching losses, delay time, and Miller plateau duration effectively during both turn-on and turn-off transient. Experimental results verify the validity and effectiveness of the proposed gate driving method.

The paper presents an in-depth experimental comparative study between a three-phase Quasi-Z-Source Inverter (qZSI) and a Boost Converter with Voltage-Source Inverter (BC+VSI). Both converters obtain identical output phase voltage value of 230 V RMS from DC input voltage in range of 400 V ÷ 550 V at a similar value of input inductor current ripple. The quality factors investigated are: power losses as well as both input inductor current and output voltage quality (considering both low- and high-frequency harmonics). Moreover, four variants of modulation methods are investigated. At switching frequency of 100 kHz results of experiments using SiC-based 6-kW laboratory models show that at identical conditions the BC+VSI configuration has lower losses and better quality of the output voltage, while qZSI has better quality of the input inductor current.

A carrier-based synchronous type single phasephase synchronous inverter (S-PSI) is proposed to develop the inverter output phase and voltage waveform. The major problem of the microgrid connected inverter is unbalanced DC supply, high switching loss, power quality and phase error. Therefore, to overcome those issues, a phase synchronous technique can perception not only conventional DC to AC inverter but also low-frequency inverter source ripple current reduction with lower switches of the inverter. However, a carrier-based synchronous PWM control technique is proposed for capable of regulating both side of the inverter input and output performance. The working performance of the S-PSI is analyzed, including steady-state behavior, efficiency, and circuit parameters. As well, the equivalence of the switching control technique and the similarity of inverter evaluate circuit parameters are exposed between this S-PSI and a traditional two-level inverter. In addition, lowpass LCL filters are utilized to convert squire wave to sine wave with same frequency and to reduce the higher harmonic distortion of the microgrid voltage. Balanced resistive load of = 11 $\Omega$ for star configuration and input DC voltage, ± 340V have assume to design the inverter. From the simulated results, the carrier-based S-PSI systems are developed the phase error of 55%, reduced 11% of THD and the conversion efficiency of 97.02%. Finally, it highly appreciated that the proposed design will improve the microgrid system.

Technological developments such as Flexible AC Transmission Systems (FACTS) can improve the power quality of the power system and can respond to the ever-increasing demand for electrical energy.Superconducting magnetic energy storage (SMES) is a FACTS device that has been used for several years at utility and industrial sites throughout the United States, Japan, Europe, and South Africa to provide both transmission voltage support and power quality to customers who are vulnerable to fluctuating power quality [1]- [3].SMES systems are classified into two groups: voltage source inverter (VSI) and current source inverter (CSI) SMES.The VSI SMES has many advantages when compared with the CSI SMES; for example, in the VSI SMES, the power rating of power electronic devices that are used in the inverter is much less than that of the CSI SMES, resulting in fewer switching and power losses.Also, the VSI SMES can be used as a Static synchronous Compensator (STATCOM) when its chopper is out of service.Moreover, for the same condition, the VSI SMES can store more energy than the CSI SMES; these advantages encouraged the authors to study VSI SMES.This type of SMES is composed of a magnetic energy storage coil with various structures and power conditioning systems that are also composed of different parts, such as AC-DC filters, a multi-level chopper, a capacitor bank, and a multi-level converter (i.e. an inverter or rectifier).These power conditioning systems are also used in many different sustainable energy systems, such as bio fuels, solar power, wind power, wave power, geothermal power, and tidal power.The converter is an interface between the power network and the capacitor bank and controls the electrical energy exchange between the two.Likewise, the chopper is also an interface between the magnetic energy storage coil and the capacitor bank, and controls electrical energy exchange between them.To store the electrical energy in the capacitor bank and the magnetic energy storage coil in the range of mega joules, it is necessary to employ high power-rating converters; to overcome the limitations of the current and voltage range of the semiconductors, multi-level converters are used.The advantages of using such converters include reducing voltage on the switches, harmonic order correction, decreasing or eliminating lateral equipment, decreasing switching frequency, decreasing total harmonic distortion (THD), decreasing switching losses, and decreasing the output current ripple.

The most admired alternative to conventional energy sources is solar energy. In north-eastern regions of India, where availability of sun is unpredictable but irradiance level is high, special observation is needed to upgrade the solar collection systems. The main objective of the research work is to develop a renewable system, which can extract maximum voltage using dual axis movable surface and design a cascaded converter, which can further increase the voltage while maintaining high efficiency. The output of the smart independent self-regulating solar panel hardware model proposed in this paper is fed into a DC–DC cascaded Boost-SEPIC system for renewable-based applications. The newly created renewable system is built to move the panel so that the most voltage is extracted. The DC–DC cascaded converter receives power from the solar panel’s output. To assess the system’s effectiveness and voltage gain, a thorough circuit analysis is carried out. The converter is tested using various duty cycles. With a 50% duty ratio and 90% efficiency, the suggested converter produces a 40 V DC output from a 20 V DC input voltage from a solar panel. Results from an experimental prototype are used to verify the converter’s viability.

In this paper, a new 23-level inverter topology has been proposed with two different modulation schemes, viz., Nearest Level Control (NLC) and Unipolar Phase Disposition (UPD) techniques. It comprises six unidirectional switches, three bidirectional switches, and five DC sources. A backend H-bridge is not needed to produce negative voltage levels because all levels are naturally produced. The main advantage of this topology is that in every state, only three switches are in conduction mode, and the rest are in the OFF state. Here, switching losses are significantly reduced due to the NLC technique's fundamental switching frequency, which is also particularly appropriate for a wide range of levels. Similarly, the UPD technique is a high switching frequency technique and because of absolute function, the number of carrier count can be reduced by half as compared with the conventional In-Phase Disposition (IPD) technique. Finally, with a step-change in input dc voltage, the proposed topology has been tested with two different control schemes and validated through MATLAB/Simulink platform.KeywordsMultilevel DC link inverterNearest level controlUnipolar phase disposition