- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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A Non-Isolated Buck-Boost DC-DC Converter with Continuous Input Current for Photovoltaic Applications
摘要： High-power grinding mills are used in the cement and mining industries to crush clinker or copper ore and grind these materials to fine powder. The multi-megawatt speed-controlled mill drives operate at a very low angular speed. Synchronous motors with a high number of pole pairs are used as the prime movers. They are traditionally fed by load-commutated thyristorized cycloconverters. These are prone to failure modes that can lead to excessive torque pulsations and high overcurrents. The huge stator, which was built as a separate ring-shaped structure around the tubular mill, may then get mechanically displaced, and the operation of the plant is interrupted. A novel and reliable direct drive uses a voltage source inverter that operates at the unity power factor for increased efficiency. Synchronous optimal pulsewidth modulation ensures a low harmonic current distortion and reduced switching losses at a very low switching frequency. The optimization of the pulse patterns takes the anisotropic magnetic properties of a separately excited synchronous motor into account. The implementation in a 23-MW semiautonomous grinding mill installed in a Zambian copper mine is intended.
关键词： Alternators,pulse width modulation inverters,gradient methods,ball milling,software algorithms,variable speed drives,Fourier transform
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Curve Correction of the Energy Yield by Flexible Photovoltaics for VIPV and BIPV Applications Using a Simple Correction Factor
摘要： High-power grinding mills are used in the cement and mining industries to crush clinker or copper ore and grind these materials to fine powder. The multi-megawatt speed-controlled mill drives operate at a very low angular speed. Synchronous motors with a high number of pole pairs are used as the prime movers. They are traditionally fed by load-commutated thyristorized cycloconverters. These are prone to failure modes that can lead to excessive torque pulsations and high overcurrents. The huge stator, which was built as a separate ring-shaped structure around the tubular mill, may then get mechanically displaced, and the operation of the plant is interrupted. A novel and reliable direct drive uses a voltage source inverter that operates at the unity power factor for increased efficiency. Synchronous optimal pulsewidth modulation ensures a low harmonic current distortion and reduced switching losses at a very low switching frequency. The optimization of the pulse patterns takes the anisotropic magnetic properties of a separately excited synchronous motor into account. The implementation in a 23-MW semiautonomous grinding mill installed in a Zambian copper mine is intended.
关键词： Alternators,ball milling,pulse width modulation inverters,gradient methods,software algorithms,variable speed drives,Fourier transform
更新于2025-09-19 17:13:59
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An Integrated Semi-Double Stage based Multilevel Inverter with Voltage Boosting Scheme for Photovoltaic Systems
摘要： This paper proposes a single-phase, seven-level, transformerless inverter, employing a semi-double stage based conversion technique, which is particularly suitable for PV applications. The proposed configuration achieves voltage boosting using a non-isolated interleaved buck-boost converter, which is fused with the inverter configuration through two switched capacitors (SC). The interleaved front-end boost stage is capable of achieving a voltage gain of three while resulting in reduced peak current stress on the switching devices. In this topology, a part of the load power is transferred directly from the PV source, while the other part is transferred through the SCs. The proposed topology and the associated PWM technique are capable of reducing the leakage current by isolating the terminals of the PV source during the freewheeling state. This paper also presents a thorough analysis of the stray capacitor voltage and the common-mode voltage (CMV). These analyses reveal that the high-switching frequency transitions are eliminated in both of these waveforms. Furthermore, the proposed topology results in the reduction of the low-frequency transitions in the stray capacitor voltage and the CMV, which results in further reduction of the leakage current. The simulation and experimental results are in agreement with the mathematical analysis of the proposed inverter.
关键词： Leakage current minimization,Pulse width modulation inverters,Multilevel-inverter,Voltage boosting,Semi-double stage system,Photovoltaic systems
更新于2025-09-11 14:15:04