This paper proposes a novel high-efficiency generation technique for photovoltaic(PV) system,named maximum power point capturing(MPPC) technique. This is an aperiodic perturbation MPPC technique compared to the conven...This paper proposes a novel high-efficiency generation technique for photovoltaic(PV) system,named maximum power point capturing(MPPC) technique. This is an aperiodic perturbation MPPC technique compared to the conventional periodic perturbation maximum power point tracking technique. Firstly, under a closed-loop circuit and an open-loop circuit,the complete I-V curves and P-V curves are defined. Secondly, the proposed MPPC technique is based on the complete I-V curves and a practical model of solar PV systems.The proposed method realizes that maximum power point(MPP) is captured online, and its control strategy is designed to set a steady operating area around MPP. The duty cycle keeps constant when the operating point is within the steady operating area, i.e., aperiodic perturbation, and when the operating point is outside the steady operating area, MPPC is triggered to capture a new MPP with an updated steady operating area. Simulation results demonstrate that no oscillations exist in steady-state;dynamic performances are improved;and only two perturbations are required to capture the new MPP. Using the proposed MPPC method,low voltage ride through and high voltage ride through can be prevented.展开更多
我国具有丰富的潮流能资源,但是存在潮流流速偏低、难以高效利用等问题。潮流能水轮机变桨距技术的利用,可有效提高潮流能资源利用效率。以提高潮流能水轮机高效获能为目标,分析了水轮机叶片桨距角对潮流能水轮机获能的影响规律,研究了...我国具有丰富的潮流能资源,但是存在潮流流速偏低、难以高效利用等问题。潮流能水轮机变桨距技术的利用,可有效提高潮流能资源利用效率。以提高潮流能水轮机高效获能为目标,分析了水轮机叶片桨距角对潮流能水轮机获能的影响规律,研究了水轮机变桨距技术原理及控制策略。在20 k W潮流能水轮机中运用了电动变桨距技术,根据潮流流速的不同,使用最大功率点追踪控制算法控制桨距角,并对机组运行过程进行实时测试。机组运行数据表明,与非变桨水轮机相比,变桨式潮流能水轮机可有效提高其获能效率。展开更多
基金supported in part by Australian Research Council (ARC) Discovery Project (No. DP170104426)
文摘This paper proposes a novel high-efficiency generation technique for photovoltaic(PV) system,named maximum power point capturing(MPPC) technique. This is an aperiodic perturbation MPPC technique compared to the conventional periodic perturbation maximum power point tracking technique. Firstly, under a closed-loop circuit and an open-loop circuit,the complete I-V curves and P-V curves are defined. Secondly, the proposed MPPC technique is based on the complete I-V curves and a practical model of solar PV systems.The proposed method realizes that maximum power point(MPP) is captured online, and its control strategy is designed to set a steady operating area around MPP. The duty cycle keeps constant when the operating point is within the steady operating area, i.e., aperiodic perturbation, and when the operating point is outside the steady operating area, MPPC is triggered to capture a new MPP with an updated steady operating area. Simulation results demonstrate that no oscillations exist in steady-state;dynamic performances are improved;and only two perturbations are required to capture the new MPP. Using the proposed MPPC method,low voltage ride through and high voltage ride through can be prevented.
文摘我国具有丰富的潮流能资源,但是存在潮流流速偏低、难以高效利用等问题。潮流能水轮机变桨距技术的利用,可有效提高潮流能资源利用效率。以提高潮流能水轮机高效获能为目标,分析了水轮机叶片桨距角对潮流能水轮机获能的影响规律,研究了水轮机变桨距技术原理及控制策略。在20 k W潮流能水轮机中运用了电动变桨距技术,根据潮流流速的不同,使用最大功率点追踪控制算法控制桨距角,并对机组运行过程进行实时测试。机组运行数据表明,与非变桨水轮机相比,变桨式潮流能水轮机可有效提高其获能效率。
