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oe1(光电查) - 科学论文

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  • [IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Ageing Mitigation Control Method for Power Devices in Multilevel Inverters in Standalone PV Systems

    摘要: Multilevel inverters (MIs) have become widely used in photovoltaic (PV) systems for their high efficiency, reduced leakage currents, and reduced EMI levels. Although MIs suffer from unequal thermal stresses in power devices that lead to aging of power device with their continuous operation. Therefore, this paper proposes a new aging mitigation control (AMC) method to enhance the reliability of MIs against the aging effects in power devices. The operation of the proposed AMC method has three operating modes that are adapted according to the level and type of aging. In small and medium aging levels, the proposed method preserves the full output power ratings of the inverter with maximum energy extraction from PV modules. Whereas, in high aging level region and multiple devices failures, the proposed method reduces the output power so as to maintain continuous operation of the inverter without harmful consequences. The simulation and experimental results with comparisons to conventional methods show effective performance of the proposed AMC method.

    关键词: lifetime,multilevel inverters (MIs),pulse width modulation (PWM),reliability,photovoltaic (PV),aging

    更新于2025-09-04 15:30:14

  • [IEEE 2018 International Conference on Smart Grid and Clean Energy Technologies (ICSGCE) - Sg. Long, Cheras, Kajang, Malaysia (2018.5.29-2018.6.1)] 2018 International Conference on Smart Grid and Clean Energy Technologies (ICSGCE) - H2D4-Type Single Phase Transformer-Less Inverter with Reactive Power Control for Grid-tied PV System

    摘要: Transformer-less inverter is popular for grid-tied photovoltaic (PV) system due to low cost, smaller size and higher efficiency. However, one of the technical challenges, which need to be handled carefully, is the issue of leakage current. Moreover, an inverter must be capable of controlling the reactive power to a certain extend to maintain the power factor (PF) close to unity. Therefore, many inverter topologies have been proposed. In this paper, a new four diodes and two IGBT switch based H2D4-type highly efficient transformer-less inverter is proposed that can handle the issue of leakage current maintaining low total harmonic distortion (THD) and higher PF where the common mode (CM) voltage is maintained constant. As a result, the leakage current deceases and the conduction loss as well as size of the system is decreased due to minimum number of IGBT switches. Furthermore, two control systems are proposed to control the reactive power with desire PF. The comparison among proposed H2D4 topology and conventional neutral point clamped (NPC) and H6 topology have been analyzed in this paper. To validate the accuracy of the theoretical analysis, the compared topologies are simulated in MATLAB/Simulink software. It is found that the PLL and PI closed loop control based H2D4 inverter topology controls the reactive power maintaining a low current THD with higher efficiency and high PF as compared to the system with only PI control based topology.

    关键词: total harmonic distortion,leakage current,H2D4 topology,reactive power,transformer-less inverter,power factor,grid connected photovoltaic

    更新于2025-09-04 15:30:14

  • [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) - A New Five-Level Inverter Topology with Voltage Controller for Grid-Connected PV System

    摘要: Photovoltaic (PV) systems are growing in demand due to the recent drop in prices of the solid state components. However, the quality of the output of the PV systems are still lacking behind and this is a major problem while connecting the system to the grid. Inverters being the brains of a solar PV system need to be made smarter and better. Multi-level inverters are one of the most popular types of inverters for grid-connected PV systems due to the higher quality output they can produce than other inverters. One of the key features they provide is the minimization of total harmonic distortion (THD) and electromagnetic interference which tackles leakage current issue. So, in this paper a new five-level inverter topology for grid-tie PV is proposed which is controlled using a new voltage controller that ensures higher efficiency while enhancing the stability of the system. The suggested closed loop voltage controller method additionally provides the ability to provide constant or adjustable voltage to the grid. In this proposed topology the voltage controller enables the PV system to provide high quality power to the grid which is vastly important. To validate the accuracy of the theoretical analysis, the control technique was applied to the existing multi-level inverter topology and then has been simulated in MATLAB/Simulink software. Moreover the five-level output provides a much better output and better PF then other existing topologies.

    关键词: closed loop system,total harmonic distortion (THD),Solar photovoltaic (PV) system,multi-level inverter,sinusoidal pulse width modulation (SPWM),voltage controller

    更新于2025-09-04 15:30:14

  • [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) - A Novel Compensation Current Control Method for Grid-Connected PV Inverter to Improve Power Quality in Micro-Grid

    摘要: This paper presents a new control method for grid-connected pulse width modulation (PWM) inverters to reduce the output current harmonic distortion in a wide range of applications, including photovoltaic (PV) inverter. The proposed control method is designed to eliminate harmonics in micro-grid and to correct the system unbalance. The proposed technique is able to increase the inverter output current around 18 times of conventional one. Another advantage of the proposed control method is that it can be easily adopted into the distributed generation (DG) control system without the installation of extra hardware. The proposed control method comprises of the advance synchronous reference frame method (ASRF).

    关键词: photovoltaic (PV),micro-turbine (MT),power quality,three-phase grid-connected inverter,Distributed generation (DG)

    更新于2025-09-04 15:30:14

  • [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) - Automated Planning of Rooftop PV Systems with Aerial Image Processing

    摘要: The increasing prevalence of photovoltaic (PV) panels for microgrid and off-grid energy applications makes affordable PV planning an important issue. Since recording rooftop area and dimensions traditionally required on-site measurements, the process was expensive, slow, and hard to scale. This research develops software that uses image processing for roof detection. Satellite images feed into the software, which estimates the rooftop area receiving solar exposure in that area as well as the number of individual buildings receiving solar exposure. In this way, entire villages can be analyzed automatically, and PV installations planned from afar, rather than requiring a human taking measurements of each building from the ground. This research further develops a GUI to accomplish this rooftop classification for users around the globe, making this capability available even to parties with low resources who would benefit from access to electricity. In this way, the study makes planning PV systems feasible and affordable for many scales of installation, from a single home to a city of numerous assorted buildings.

    关键词: demand forecasting,solar panels,object detection,photovoltaic systems,microgrids

    更新于2025-09-04 15:30:14

  • [IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Passive Filter Design to Mitigate Dead-Time Effects in Three-Level T-Type NPC Transformerless PV Inverters Modulated with Zero CMV PWM

    摘要: Common-mode voltage (CMV) can cause common-mode (CM) current in transformerless PV inverters. In practice, large CM choke is usually required to suppress the CM current. Alternatively, zero common-mode voltage (ZCMV) modulation can be applied to eliminate the CMV. But in practical applications, CMV spikes are inevitable due to the dead-time effect. Such dead-time effect can be mitigated by special PWM sequence design, however, at the expense of increasing switching losses. In this paper, our study addresses this issue by using the DC neutral-point connected LCL (NC-LCL) filter. As the differential-mode (DM) output quality is undermined with ZCMV PWM, the LCL filter parameters must be carefully designed, where both CM and DM filters need to be considered. In addition, filter design for conventional phase disposition (PD) modulation is also included as a comparison. Both simulation results and experimental results are provided for verification.

    关键词: Photovoltaic (PV) solar inverter,LCL filter design,Phase disposition modulation,T-type 3L-NPC (PD) inverter,Zero CMV modulation

    更新于2025-09-04 15:30:14

  • [IEEE 2018 International Power Electronics Conference (IPEC-Niigata 2018-ECCE Asia) - Niigata (2018.5.20-2018.5.24)] 2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia) - The Lifetime Assessment of a Micro-Inverter for PV Applications

    摘要: Recently, introducing grid-tied PV systems is recommended in many countries. The inverter lifetime in PV applications is affected by their operating conditions. That is affected by the thermal loading of the power devices lifetime of electrolytic capacitors. Especially, the electrolytic capacitors at the DC-link to compensate the power ripple decreases when the ambient temperature increases. To improve the lifetime, a micro-inverter with an active buffer at the DC-link is introduced in this paper. In this micro-inverter, the DC-link electrolytic capacitor is replaced with a ceramic capacitor that has small capacitance. However, the reliability performance of the entire micro-inverter has not been evaluated. This paper thus assesses the lifetime of the micro-inverter considering the operational conditions (i.e., ambient temperature and solar irradiance, also referred to as mission profiles). A comparison between the proposed circuit with an active buffer and the conventional circuit based on a boost chopper is performed in this paper. It is revealed that the lifetime of the micro-inverter is very long. This is due to the over-designed power devices.

    关键词: Photovoltaic,Lifetime estimation,Micro inverter

    更新于2025-09-04 15:30:14

  • Novel Design for Thermal Management of PV Cells in Harsh Environmental Conditions

    摘要: The abundance of solar energy is a blessing in the Arabian Peninsula, where more than 2000 kWh/m2 density has been recorded annually. This has resulted in sincere consideration of PV harvesting in the energy matrix and smart grid. However, artefacts such as degradation of PV efficiency due to the high temperature effect have to be addressed. This paper presents a novel design of a PV cooling system using water to mitigate the effect of high temperature. Several experiments have been conducted, and the results have been analyzed. It has been found that the collected water from the panel after 40 min of cooling gained a temperature of 10 ?C approximately, during December 2016. Eventually, the efficiency was improved by 10.35% (without using MPPT) using water at ambient temperature (24 ?C) compared to the non-cooled panel. Moreover, the temperature of the panel during solar peak hours dropped from 64.3 ?C to 32 ?C and from 59 ?C to 27 ?C in 3 min for the back and front surface, respectively. These results, which are the ?rst of their kind in Qatar, constitute good incentives and pave the way for further investigation to enhance PV ef?ciency in harsh environments. This would be of paramount signi?cance, especially for scaling up PV deployment, as is planned in Qatar and GCC countries in their 2030 vision.

    关键词: overheating,ef?ciency,photovoltaic,water cooling,heat transfer,renewable energy

    更新于2025-09-04 15:30:14