- 标题
- 摘要
- 关键词
- 实验方案
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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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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Luminescence from poly-Si films and its application to study passivating-contact solar cells
摘要： Droop control is a well-known strategy for the parallel operation of inverters. However, the droop control strategy changes its form for inverters with different types of output impedance, and so far, it is impossible to operate inverters with inductive and capacitive output impedances in parallel. In this paper, it is shown that there exists a universal droop control principle for inverters with output impedance having a phase angle between ?(π/2) rad and (π/2) rad. It takes the form of the droop control for inverters with resistive output impedance (R-inverters). Hence, the robust droop controller recently proposed in the literature for R-inverters actually provides one way to implement such a universal droop controller that can be applied to all practical inverters without the need of knowing the impedance angle. The small-signal stability of an inverter equipped with the universal droop controller is analyzed, and it is shown to be stable when the phase angle of the output impedance changes from ?(π/2) rad to (π/2) rad. Both real-time simulation results and experimental results from a test rig consisting of an R-inverter, an L-inverter, and a C-inverter operated in parallel are presented to validate the proposed strategy.
关键词： parallel operation of inverters,R-inverters,universal droop controller,robust droop controller,C-inverters,output impedance,L-inverters
更新于2025-09-16 10:30:52
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AIP Conference Proceedings [AIP Publishing INTERNATIONAL SYMPOSIUM ON GREEN AND SUSTAINABLE TECHNOLOGY (ISGST2019) - Perak, Malaysia (23–26 April 2019)] INTERNATIONAL SYMPOSIUM ON GREEN AND SUSTAINABLE TECHNOLOGY (ISGST2019) - Single - phase phase locked loop with DC offset and noise rejection capability for photovoltaic inverters in distributed generation
摘要： Green and sustainable energy could not be realised without stable and reliable grid. When green energy such as photovoltaic (PV), is injected to the grid, it requires accurate synchronization (voltage, frequency and phase angle). This can be done via phase locked loop (PLL). The performance of the conventional PLL is poor due to steady-state error. Moreover, it fails to operate under weak grid condition, i.e., with dc offset and with noise. Although many PLLs have been proposed in the literature to eliminate the steady-state error, the performance of the PLLs under weak grid condition is still poor. In this paper, a new PLL is proposed to eliminate the DC offset and noise. The results show that the proposed PLL is able to completely eliminate the perturbation of 30 % DC bias, 0.095 W of noise, with a settling time of 150 ms. 10% of magnitudes of low order 3rd, 5th and 7th harmonics are also reduced considerably. Furthermore, the under shoot of the estimated frequency waveform is reduced up to 8 Hz. With the proposed PLL, the green energy can be harvested without any grid stability concerns.
关键词： photovoltaic inverters,phase locked loop,DC offset,noise rejection,distributed generation
更新于2025-09-16 10:30:52
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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) - Open-source integrated optical modelling with RayFlare
摘要： An output line-to-line voltage model-based fault diagnostic technique is presented in this paper. From the theoretical analysis of the output voltage under normal and faulty conditions, a preprocessing method is developed to extract fault features from diagnosis eigenvalue. A voltage envelope line is generated by the proposed voltage envelope function. By comparing the preprocessed diagnosis eigenvalue and the voltage envelope, single-switch open-circuit faults can be located precisely. Because the proposed method does not rely on the accurate amplitude of the output line-to-line voltage, the influence of the load changing is minimized and simple hardware is adopted, which has advantages of low cost, high reliability, and short diagnosis time. Moreover, as long as the inverter output voltages have the feature of periodic nonpositive and nonnegative, this method is valid no matter what control strategy is adopted by the inverter and no control signal is required for the diagnosis process. The prototype system is tested to validate the adaptability of the proposed method under different conditions, such as the diverse loads, various control strategies, and fault-occurrence time.
关键词： Fault diagnosis,fault location,open-circuit fault,inverters
更新于2025-09-16 10:30:52
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Technical and Economic Optimal Solutions for Utility-Scale Solar Photovoltaic Parks
摘要： Solar energy has shown to be a successful renewable source, wherefore large investments are planned in the upcoming decades. This work aims at developing technical and economical solutions to optimize a utility‐scale grid connected solar photovoltaic park with an installed capacity of 24 MWp. Several successive simulations were automatically performed with the PVSyst software, so that each influencing parameter is individually analyzed. Moreover, a comprehensive study touching relevant aspects, such as central versus string inverters, landscape versus portrait dispositions, the optimal tilt angle (for fixed tilt systems), backtracking strategy (for single axis tracking systems), shading limit angle, and pitch is performed with the objective of finding the configuration leading to the higher grid injected energy output. The levelized cost of energy (LCOE) was obtained for 12 different cases in which, for both fixed tilt and single‐axis tracking (SAT), central and string inverters and portrait/landscape disposition were considered. The lowest LCOE achieved was 32.23 €/MWh, which is a clear indication of the competitiveness of the solar Photovoltaic (PV) technology. The most economic viable solution is characterized by the employment of an SAT system with the backtracking strategy, together with string inverters and module portrait disposition.
关键词： string inverters,levelized cost of energy (LCOE),optimization,design parameters,economic analysis,utility‐scale solar PV park
更新于2025-09-16 10:30:52
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Testing guidelines for connection of solar photovoltaic farm to distribution grid: The Malaysian experience
摘要： Solar photovoltaic technology is intermittent in nature and employs power converters for grid-interconnection, which can bring stability and power quality (PQ) issues to the power grid. Therefore, a set of testing guidelines is required to assure that solar plants comply with the grid and inverter requirements. As such, this article presents comprehensive testing guidelines for the interconnection of solar systems into Malaysian power grid, including inverter and PQ tests. The test points, conditions, parameters and acceptable limits for both tests are discussed in detail. This article also presents the results of a case study in which the testing guidelines were applied to examine the PQ of an actual grid-connected solar photovoltaic plant in Malaysia and to assess the performance of the smart inverter used in the tested solar system. The testing outcomes, which were recorded by a PQ analyser, showed that the tested solar system was in compliance with all the requirements stipulated in the testing guidelines. The findings presented in this article will help relevant parties to understand these solar testing guidelines and serve to promote the wide deployment of solar technology towards a clean and sustainable future.
关键词： testing guidelines,photovoltaic systems,power quality,renewable energy sources,inverters
更新于2025-09-16 10:30:52
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A Reconfigurable Solar Photovoltaic Grid-Tied Inverter Architecture for Enhanced Energy Access in Backup Power Applications
摘要： In this paper, a photovoltaic (PV) reconfigurable grid-tied inverter (RGTI) scheme is proposed. Unlike a conventional GTI that ceases operation during a power outage, the RGTI is designed to act as a regular GTI in the on-grid mode but it is reconfigured to function as a DC-DC charge-controller that continues operation during a grid outage. During this period, the RGTI is tied to the battery-bank of an external UPS based backup power system to augment it with solar power. Such an operation in off-grid mode without employing high-bandwidth communication with the UPS is challenging, as the RGTI control must not conflict with the battery management system of the UPS. The hardware and control design aspects of this requirement are discussed in this paper. A battery emulation control scheme is proposed for the RGTI that facilitates seamless functioning of the RGTI in parallel with the physical UPS battery to reduce its discharge current. A system-level control scheme for overall operation and power management is presented to handle the dynamic variations in solar irradiation and UPS loads during the day, such that the battery discharge burden is minimized. The design and operation of the proposed RGTI system are independent of the external UPS and can be integrated with an UPS supplied by any manufacturer. Experimental results on a 4 kVA hardware setup validate the proposed RGTI concept, its operation and control.
关键词： Solar PV,Battery,Grid-tied Inverters,dual-mode inverters,UPS,Closed-loop control
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE Energy Conversion Congress and Exposition (ECCE) - Baltimore, MD, USA (2019.9.29-2019.10.3)] 2019 IEEE Energy Conversion Congress and Exposition (ECCE) - Interharmonics Reduction in Photovoltaic Systems with Random Sampling MPPT Technique
摘要： An increasing penetration level of grid-connected Photovoltaic (PV) systems raises a concern regarding power quality problem, in particularly, interharmonics. According to previous research, the perturbation from the Maximum Power Point Tracking (MPPT) algorithm is one of the main root-cause of interharmonic emission in PV systems. In general, the interharmonic characteristics are strongly dependent on the sampling rate of the MPPT algorithm. A slow sampling rate of the MPPT algorithm can minimize the interharmonic emission but it results in poor tracking performance of the MPPT algorithm. Thus, there is a trade-off between the interharmonic emission and the MPPT efficiency when selecting the MPPT sampling rate. To overcome this problem, a new MPPT technique implemented with a random sampling rate is proposed in this paper. The proposed method randomly selects the MPPT algorithm sampling rate during each perturbation. This method is simple to be implemented but results in a significant reduction in the interharmonics of the output current and, at the same time, a high MPPT efficiency. The effectiveness of the proposed method has been validated experimentally with a single-phase grid-connected PV system. Moreover, the effect of interharmonic cancellation when implementing the proposed random sampling MPPT technique with parallel-connected PV inverters has also been demonstrated.
关键词： inverters,interharmonics,maximum power point tracking (MPPT),power quality,Photovoltaic (PV) systems
更新于2025-09-12 10:27:22
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Advances in reduction of total harmonic distortion in solar photovoltaic systems: A literature review
摘要： The use of photovoltaic (PV) systems has increased in recent years due to the high demand for clean energy sources. PV systems can utilize abundant and free energy from the sun, which is a substantial advantage. However, compared with other renewable technologies, the PV system still faces major obstacles such as high cost and low efficiency. In addition, fluctuating incident energy from the sun creates harmonics in the generated power that might lead to undesirable system performance. Total harmonic distortion (THD) is the ratio of distorted power to the main power of the signal, and is most commonly used to indicate the amount of signal distortion. THD has become a serious concern as more PV systems are integrated into grid systems. Previous research and reviews have attempted to reduce THD and its effect, but unfortunately focused on reducing THD at individual parts of the PV system. For the first time, this study holistically and systematically reviews the advances in THD reduction techniques for the entire PV system. The causes of harmonics, current solutions, and research gaps for further investigation are described in detail. Moreover, the current THD reduction techniques used in each stage of the PV system are compared, including their main benefits and drawbacks. Finally, this study recommends the use of adaptive filters as a possible solution for THD reduction because these filters have effectively reduced noise and disturbance in other systems.
关键词： THD reduction,DC-DC converter,harmonics,THD,photovoltaic,inverters,PV,adaptive filters,renewable energy,MPPT
更新于2025-09-12 10:27:22
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Computer Simulation and Investigations of the Roof Mount Photovoltaic System
摘要： The interest in the renewable energy sources is increasing due to the depletion of the conventional energy sources and the environmental pollution. In this paper we present a computer simulation and investigations of the roof mounted photovoltaic system. The results of the generated power of the 5kW built-in photovoltaic system by months over a period of 5 years are presented. Depending on the meteorological conditions, the investigated photovoltaic system generates year-round energy necessary for the needs of the household.
关键词： computer simulation inverters,photovoltaic systems,Computational modeling
更新于2025-09-12 10:27:22