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This paper proposes a single-stage direct AC to high-frequency (HF) AC resonant converter based on LLC configuration for induction heating (IH) systems or HF applications. Unlike conventional converters for IH systems, the proposed topology converts the utility frequency to HF AC in a single stage without using a DC link inductor and capacitors and takes the advantages of LLC configuration. Additionally, it improves the power factor to 0.9–1, lowers the THD (3.2% experimentally), and protects against the high-frequency components. An embedded control scheme was designed to keep the HF current oscillating at a resonant frequency, ensuring zero-voltage switching. The operating principle of the proposed topology was investigated using mathematical equations and equivalent circuits. Finally, it was verified using computer simulation, and an experimental prototype of 1.1 kW was developed to demonstrate the proposed topology's uniqueness. [ABSTRACT FROM AUTHOR]

A dual output dual-frequency (DODF) resonant converter-based AC-AC induction heating (IH) by using asymmetrical duty cycle (ADC) control is presented in this paper. The proposed scheme gives two outputs with independent power control, which improves input power factor and achieves zero voltage switching (ZVS) with a wide range of operations. It includes two pairs of two half-bridge series resonant converters, each pair having one common capacitor along with various resonant frequencies. These converters are modulated with the ADC control scheme to obtain smooth operation. The proposed topology doesn't use the DC stage; it is directly connected to the power supply to produce high-frequency AC output. With the use of direct connection, the converter components are reduced when compared to conventional converters. There will be a reduction in voltage drop, power losses, cost of the converter and which will result in improved efficiency. Simulation results are obtained from PSIM 11.1.7 software. This scheme controls two different loads with an efficiency of 98.25%. [ABSTRACT FROM AUTHOR]

This article presents a step-up multilevel inverter with a reduced number of devices. The inverter can realise nine output voltage levels with 4 times higher input source voltage at the output with 11 switching devices. The inverter uses switched capacitor (SC) technique to step up the output voltage. One of the important drawbacks of the recently proposed SC-based MLI is the higher input current ripples or spikes due to the capacitor charging states. These high ripples hamper the life of the source such as photovoltaic (PV) array or fuel cells. The proposed inverter can lower the input current ripples than others as well as can provide the maximum boosting at the output voltage. A detailed discussion on the operating principle, selection procedure of components, and power losses analysis of the proposed inverter has been presented. Furthermore, a comparative evaluation shows a significant reduction of input current spikes and component count of the proposed inverter than others. Moreover, the proposed inverter provides a lower cost function per boosting factor per level as compared to others. The performances of the inverter are verified by an extensive simulation and experimental study. The inverter works well with desired performances under different load conditions. [ABSTRACT FROM AUTHOR]

In this study, a new circuit topology using a Z-source resonant inverter (ZSRI) for high power applications in large-air-gap contactless power transfer (CPT) systems, has been investigated. The main shortcoming of a large-air-gap CPT system is the poor power transfer efficiency due to low magnetic coupling. In order to minimize this shortcoming and to improve the overall performance of the system by boosting the power transfer capability, in this paper a CPT system with the newly developed circuit topology using high frequency Z-source resonant inverter has been proposed. Using the newly developed circuit topology for the CPT system, it has been observed that the overall performance of the system has been improved to a reasonable level with a purely sinusoidal resonant current flowing through the primary side. Therefore, no harmonics will be injected into the source. The proposed CPT system with an air gap of 16 cm and a misalignment of 3 cm has been simulated using the Maxwell finite element tool and Simplorer circuit simulation software for an output power of 2 kW.

Partial shading is a significant limitation that decreases the maximum power output of large photovoltaic (PV), and building integrated photovoltaic (BIPV) arrays installed in modern buildings. One of the optimum solutions to mitigate the difficulty related to partial shading is applying different interconnected fixed BIPV array configurations. This research article aims to modelling, simulation, and performance analysis of a novel conventional 7 × 8 Quarter-Tied (QrTd) fixed BIPV array configuration under the centre, left staircase, frame, left corner, diagonal, and left side shading pattern cases in Matlab/Simulink. Moreover, a comprehensive study with existing conventional fixed BIPV array configurations such as Series-Parallel (SePl), Bridge-Linked (BdLk), Honey-Combed (HnCb), Triple-Tied (TrTd), Total-Cross-Tied (TtCrTd) array interconnections is also executed. The variable parameters for performance evaluation include global maximum power point (GlMxPoPt), mismatch losses (MmLs), fill factor (FiFa), efficiency (Effy), relative power loss (RlPwLs) and relative power gained (RlPwGn). Experimental validation under two partial shading cases is also reported for the justification of simulation results. The simulation results infer that the proposed QrTd configuration improves GlMxPoPt by 4.31%, reduces MmLs by 3.54%, and improves FiFa & Effy by 2.44% and 0.34%, respectively, under six different shading cases. The experimental results conclude that the proposed QrTd configuration improves GlMxPoPt by 1.62%, reduces MmLs by 1.15%, and improves FiFa & Effy by 0.65% and 0.14%, respectively, under two shading cases. Moreover, the wiring requirement and the wiring losses are also lower in the proposed QrTd configuration than in the TtCrTd configuration. [ABSTRACT FROM AUTHOR]

A novel circuit topology of modified switched boost high frequency hybrid resonant inverter fitted induction heating equipment is presented in this paper for efficient induction heating. Recently, induction heating technique is becoming very popular for both domestic and industrial purposes because of its high energy efficiency and controllability. Generally in induction heating, a high frequency alternating magnetic field is required to induce the eddy currents in the work piece. High frequency resonant inverters are incorporated in induction heating equipment which produce a high frequency alternating magnetic field surrounding the coil. Previously this high frequency alternating magnetic field was produced by voltage source inverters. But VSIs have several demerits. So, in this paper, a new scheme of modified switched boost high frequency hybrid resonant inverter fitted induction heating equipment has been depicted which enhances the energy efficiency and controllability and the same is validated by PSIM.

On-grid and off-grid building integrated photovoltaic (BIPV) systems require a large size BIPV array (LSBA) as their major renewable energy generator. Partial Shading (PS) significantly contributes to power loss in LSBA. One effective solution to mitigate the adverse effect of PS in LSBA is the application of fixed or static BIPV array configurations (BIPV-ACs). This research article critically compares the different fixed BIPV-ACs for modelling, designing and critical analysis of LSBA. Different existing and proposed fixed BIPV-ACs are modelled and simulated in MATLAB/Simulink under six dissimilar cases of PS patterns. Further, the performance is investigated in terms of global maximum power point (G-M-PP), mismatch loss (ML), fill factor (FF), efficiency (η), relative power loss (RPL) and relative power gained (RPG) to identify the best BIPV-AC. Experimental justification of simulation results under two PS pattern cases is reported. The best BIPV-ACs with high G-M-PP and low ML are Total-Cross-Tied (TCT), Triple-Tied (TT), Modified Triple-Tied (M-TT) and Hybrid Bridge-Linked Total-Cross-Tied (H-BL-TCT). Finally, the comprehensive critical analysis reveals that the H-BL-TCT array is the best performing array with low ML, high FF and η, and high G-M-PP with low wiring requirements than the TCT array. The simulation results conclude that the H-BL-TCT array improves G-M-PP by 6.40 %, reduces ML by 4.23 %, and improves FF & η by 4.58 % and 0.54 %. The experimental results infer that the H-BL-TCT array improves G-M-PP by 0.83 %, reduces ML by 0.75 %, and improves FF & η by 0.88 % and 0.09 %. [ABSTRACT FROM AUTHOR]