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Modulation Effects on Power-loss and Leakage Current in Three-Phase Solar Inverters
摘要： Three-phase solar inverters can be operated with different modulation strategies such as sinusoidal pulse-width modulation (SPWM), space vector modulation (SVM), third-harmonic injection PWM (THIPWM). The selection of the modulation strategy can significantly affect PV leakage currents and power losses and compromise the inverter performance. This paper presents a detailed analysis of traditional and modified modulation effects on power semiconductor losses and photovoltaic (PV) leakage current. The research focuses on a three-phase Three-Level T-type Neutral Point Clamped (3L-TNPC) solar inverter. A detailed exploration of traditional SPWM and SVM is presented and a new modified modulation strategy referred to as two-triplen harmonic injection PWM (2THIPWM) which can substitute the SVM scheme. Analytical expressions are derived for the proposed 2THIPWM strategy which can be used for the SVM power-loss approximation. The comparison between 2THIPWM and SPWM shows a conduction-loss difference greater than the 5% normalized range. The modulation strategies are discussed with respect to the PV common mode current signature and specific design techniques in modulation lead to reduced leakage currents for safety compliance. The theoretical and experimental results obtained using a 3L-TNPC solar inverter are presented to evaluate the modulation strategies and their impact on performance.
关键词： three-phase modulation,PV leakage current,Three-phase three-level (3L) TNPC power semiconductor losses
更新于2025-09-11 14:15:04
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Calibration of Measuring Network of Leakage Current Tester by High Frequency Current Source
摘要： A novel method, which is different from the high frequency voltage source method recommended by IEC 60990, is proposed in this paper. Calibration of the leakage current measuring network is realized by direct current input using high frequency current source. It has been verified that the measurement results consist with the requirements of IEC 60990.
关键词： measuring network,high frequency current source method,leakage current tester
更新于2025-09-10 09:29:36
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Effect of Ion Implantation-Induced Defects on Leakage Current Characteristics of IEMOS
摘要： We investigated the relationship between ion implantation-induced defects and electrical characteristics, especially focusing on the leak failure rate in SiC IEMOSs and PN diodes. It was found that dislocation exists in each leakage point by analyzing identical leak-failed IEMOS by emission microscopy and refraction X-ray topography. The leak failure rate of the PN diodes and IEMOS was improved with an increase in the ion implantation temperature under the implantation and annealing conditions used in this experiment. It is considered that ion implantation-induced defects lead to an increase in leak failure rates, and also enable a decrease in leak failure rates by raising the implantation temperature up to 600 °C.
关键词： activation annealing,leakage current,ion implantation,silicon carbide
更新于2025-09-10 09:29:36
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readout chip
摘要： In order to solve the leakage current saturation of Topmetal-???? ? and to maintain its low noise, Topmetal-?????? has been designed. The new chip has the same Rolling-Shutter module as Topmetal-???? ?. It contains a charge-collection electrode and a metal layer surrounding it, called guard ring. This new design contains three different sections. Section A has the same structure as Topmetal-???? ?, in that the electrode is exposed and guard ring is covered by insulating layer. Section B has both electrode and guard ring exposed. Section C has guard ring exposed but electrode covered by insulating layer. Preliminary experiments show that if coupled with CdZnTe detector, Section C of the Topmetal-?????? chip is capable of solving the leakage current saturation. Meanwhile, the electrode receives induced signal. Moreover, the charge induction efficiency is influenced by several parameters, such as thickness of adhesive epoxy resin, collecting electrode size, etc. Thus, the optimization of parameters for induction efficiency is studied by simulations. According to the simulation results, it can be concluded that thinner epoxy resin thickness and bigger anode size contribute to higher induction efficiency.
关键词： Leakage current,CdZnTe,Induced signal simulation,Topmetal,Low noise readout chip,Pixel
更新于2025-09-10 09:29:36
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Titanium coverage for plasma-induced uniform HfSiON film from Hf nanoscale islands on SiO <sub/>2</sub> /Si
摘要： Signi?cant improvement of the in-plane uniformity of an HfSiON ?lm is enabled by a Ti coverage over Hf islands on an SiO2/Si substrate. Surface diffusion of Hf during an HfSiON ?lm growth from Hf (island)/SiO2/Si structure induced by a nitrogen inductively coupled plasma (ICP) exposure is effectively suppressed by the Ti coverage. The nitrogen ICP exposure to the Ti/Hf (island)/SiO2/Si surface forms a TiN layer, which suppresses the surface diffusion of Hf by lowering the surface energy. Even a small Ti coverage of 5% is effective for the uniform Hf concentration in the HfSiON ?lm. The uniformity of the ?lm is monitored by an in vacuo noncontact AFM and a cross-sectional SEM imaging. An ex situ XPS analysis indicates that the TiN layer is sputtered by the ion bombardment and the Ti content in the ?lm decreases less than 1%. The intermixing of Si with Hf and the subsequent nitridation of the ?lm is successfully performed even the surface is covered with TiN. The mercury probe measurement revealed that the improved uniformity by the Ti coverage increases the capacitance and reduces the leakage current of the high-k dielectric ?lm.
关键词： uniform film,capacitance,HfSiON,Ti coverage,leakage current,nitrogen ICP,surface diffusion,plasma-induced,TiN layer
更新于2025-09-09 09:28:46
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Multi-Channel Tri-gate GaN Power Schottky Diodes with Low ON-Resistance
摘要： In this work we demonstrate high-performance lateral GaN power Schottky barrier diodes (SBDs) based on a novel multi-channel tri-gate architecture. A significant reduction in ON-resistance (RON) of 50%, down to 7.2 ± 0.4 ?·mm, along with a much smaller forward voltage (VF) of 1.57 ± 0.06 V, were achieved with multiple 2DEG channels (multi-channels) formed by periodic AlGaN/GaN heterostructures. We used a tri-anode structure to form Schottky contact to the multi-channels through the fin sidewalls, leading to a small turn-ON voltage (VON) of 0.67 ± 0.04 V. To simultaneously control the multi-channels and effectively spread the electric field in OFF state, a tri-gate structure was integrated in the anode, resulting in an ultra-low leakage current (IR) of ~1 nA/mm at -600 V and a high breakdown voltage (VBR) of -900 V at 1 μA/mm with grounded substrate. In addition, the devices presented promising switching performance, due to the small product of RON and reverse charge (Q), thanks to the optimized tri-gate geometry, and the high effective mobility (μe) of 2063 ± 123 cm2·V-1s-1 despite the small fin width (w) of 50 nm. Our approach combines in a unique way the excellent electrostatic control of the tri-gate structure with the high conductivity of multi-channels, offering a promising platform for future advances in GaN power devices.
关键词： tri-anode,GaN,leakage current,breakdown,SBD,tri-gate,multi-channel
更新于2025-09-09 09:28:46
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Analysis for the Minimization of Leakage and Common Mode Currents in Cascaded Half-Bridge PV Fed Multilevel Inverter
摘要： This paper gives the detailed study and analysis of the terminal voltage and the common mode voltage (CMV) for the photovoltaic (PV) fed cascaded half-bridge (CHB) multilevel inverter (MLI). The expression for the terminal voltage and CMV are also derived using switching function. The analytical waveforms obtained using the expression of the terminal voltage and CMV clearly indicate that the terminal voltage and CMV are not constant simultaneously. Thus, two PWM schemes are proposed using redundant states concept for CHB nine-level MLI without the addition of any extra circuit element. The first PWM scheme reduces the high-frequency transitions in the terminal voltage and thus, minimises the leakage current. The other PWM scheme is designed to reduce the common mode current by maintaining CMV constant. Further, the proposed PWM schemes are compared with the conventional PWM schemes. And the effect of each PWM schemes on the terminal voltage and CMV are analyzed using the given switching function analysis. The given switching function analysis is also supported with the help of simulation and experimental results. The simulation and experimental results of the proposed PWM schemes are further compared with the conventional SPWM technique.
关键词： Cascaded multilevel inverter,leakage current,common mode current,common mode voltage,terminal voltage
更新于2025-09-04 15:30:14
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Analysis of transformer less inverter for PV applications
摘要： To enhance the effectiveness and decrease the cost of a Photovoltaic (PV) system, the utilization of transformer less PV inverters is an option of expanding interest. In any case, this topology should be considered in detail, as it shows a few issues like effectiveness degradation and safety issues identified with the galvanic association between the system and the PV generator. In this research paper, a review of standalone and grid-connected PV inverter structures has been done. From one viewpoint, a few options in light of established structures have been introduced. At last parasitic capacitance in PV arrays and leakage current produced from PV systems are examined.
关键词： Grid Connected Systems,Parasitic Capacitance,Leakage Current,Photovoltaic,Transformer Less Inverters
更新于2025-09-04 15:30:14
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Study on the Physical and Leakage Current Characteristics of an Optimized High-k/InAlAs MOS Capacitor with a HfO2–Al2O3 Laminated Dielectric
摘要： High-k/n-InAlAs MOS capacitors are popular for the isolated gate of InAs/AlSb and InAlAs/InGaAs high-electron mobility transistors. In this study, a new kind of high-k/n-InAlAs MOS-capacitor with a HfO2–Al2O3 laminated dielectric was successfully fabricated using an optimized process. Compared with the traditional HfO2/n-InAlAs MOS capacitor, the new device has a larger equivalent oxide thickness. Two devices, with a HfO2 (8 nm)–Al2O3 (4 nm) laminated dielectric and a HfO2 (4 nm)–Al2O3 (8 nm) laminated dielectric, respectively, were studied in comparison to analyze the effect of the thickness ratios of HfO2 and Al2O3 on the performance of the devices. It was found that the device with a HfO2 (4 nm)–Al2O3 (8 nm) laminated dielectric showed a lower effective density of oxide charges, and an evidently higher conduction band offset, making its leakage current achieve a signi?cantly low value below 10?7 A/cm2 under a bias voltage from ?3 to 2 V. It was demonstrated that the HfO2–Al2O3 laminated dielectric with a HfO2 thickness of 4 nm and an Al2O3 thickness of 8 nm improves the performance of the high-k dielectric on InAlAs, which is advantageous for further applications.
关键词： C–V characteristics,high-k/InAlAs MOS-capacitor,HfO2–Al2O3 laminated dielectric,leakage current
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - Kota Kinabalu, Malaysia (2018.10.7-2018.10.10)] 2018 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - Transformer-less Single Phase H2D4 Inverter with Voltage Controller for Grid-tied PV System
摘要： Nowadays the transformer-less photovoltaic (PV) grid connected inverter is more popular because of its higher efficiency, compact size and lower cost. The issue of leakage current is a technical challenge, which needs to be controlled carefully. Moreover, many inverter topologies have been proposed to proficient the inverter to control the reactive power to a certain point in order to maintain the power factor (PF) close to one. In case of solar PV system, voltage fluctuation and synchronization with the utility grid is the challenging issue. Therefore, in this paper a new transformer-less inverter is proposed consisting of four diodes and two IGBT switches called H2D4 topology. The proposed topology can overcome the issue of leakage current by maintaining the common mode (CM) voltage constant while maintain low total harmonic distortion (THD) and higher PF. Because of the minimum number of IGBT switches, the leakage current and the conduction loss decrease. Besides, the size of the system is also decreased. Additionally, voltage fluctuation and synchronization are controlled by a newly proposed voltage controlled closed loop system where duty ratio is controlled. The proposed topology and the existing neutral point clamped (NPC) and H6 topologies are simulated in MATLAB/Simulink software, to clarify the theoretical analysis. It is found that the voltage controller closed loop control system of H2D4 inverter topology more efficiently control the voltage fluctuation problems while maintaining a low current THD with higher efficiency and high PF as compared with the system without control topology.
关键词： Grid connection,voltage synchronization,utility grid,total harmonic distortion,transformer-less inverter,power factor,leakage current,reactive power
更新于2025-09-04 15:30:14