当前位置: X-MOL 学术Int. Trans. Electr. Energy Syst. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Power enhancement of single-phase transformer-less grid-connected cascaded half-bridge diode clamped inverter under partial shaded photovoltaic
International Transactions on Electrical Energy Systems ( IF 1.9 ) Pub Date : 2021-07-03 , DOI: 10.1002/2050-7038.12998
Pandry Narendra Rao 1 , Lalit Mohan Saini 1
Affiliation  

This study presents a power-enhanced cascaded half-bridge (HB) diode clamped transformer-less multilevel inverter for grid-connected large-scale photovoltaic (PV) system addressing the problem of unequal power in isolated diode clamped (DC)-link due to partial shading. The HB diode clamped has the feasibility of increasing double times the DC-link voltage compared with the conventional cascaded h-bridge to enhance the inverter's power rating without compromising the count and peak inverse voltage of switching devices. Under partial shading conditions, the DC-link of individual HB suffers from different voltages and leads to unbalanced capacitor voltages. The proposed control scheme stabilizes the DC-link voltage of individual HB, extracts maximum active power from PV, and injects the same into the grid. The injected grid current total harmonic distortion satisfies the IEC 61727 and IEEE 1547 standards. PV parasitic capacitance in the transformer-less grid-connected system leads to leakage current. In the present work, LC-filters are placed among the power cells to bring these currents below 30 mA as per German standards VDE V 0126-1-1. For the planned inverter, a mathematical model using the switching function theory has been derived. The inverter's performance has been tested under partial shading conditions by using the MatLab/Simulink platform and experimentally verified with the software-in-the-loop real-time digital simulator OPAL-RT 5700.

中文翻译:

部分遮蔽光伏下单相无变压器并网级联半桥二极管钳位逆变器的功率提升

本研究提出了一种用于并网大型光伏 (PV) 系统的功率增强级联半桥 (HB) 二极管钳位无变压器多电平逆变器,解决了隔离二极管钳位 (DC) 链路中由于以下原因造成的功率不均衡问题部分阴影。与传统的级联 h 桥相比,钳位 HB 二极管具有将直流母线电压提高两倍的可行性,以提高逆变器的额定功率,而不会影响开关器件的数量和峰值反向电压。在部分遮蔽条件下,单个 HB 的直流链路受到不同电压的影响,并导致电容器电压不平衡。所提出的控制方案稳定了单个 HB 的直流母线电压,从 PV 中提取最大有功功率,并将其注入电网。注入的电网电流总谐波失真满足 IEC 61727 和 IEEE 1547 标准。无变压器并网系统中的光伏寄生电容会导致漏电流。在目前的工作中,根据德国标准 VDE V 0126-1-1,将 LC 滤波器放置在电池之间以将这些电流降低到 30 mA 以下。对于规划中的逆变器,已经推导出使用开关函数理论的数学模型。逆变器的性能已通过使用 MatLab/Simulink 平台在部分阴影条件下进行测试,并通过软件在环实时数字模拟器 OPAL-RT 5700 进行实验验证。根据德国标准 VDE V 0126-1-1,LC 滤波器放置在电池之间,以将这些电流降至 30 mA 以下。对于规划中的逆变器,已经推导出使用开关函数理论的数学模型。逆变器的性能已通过使用 MatLab/Simulink 平台在部分阴影条件下进行测试,并通过软件在环实时数字模拟器 OPAL-RT 5700 进行实验验证。根据德国标准 VDE V 0126-1-1,LC 滤波器放置在电池之间,以将这些电流降至 30 mA 以下。对于规划中的逆变器,已经推导出使用开关函数理论的数学模型。逆变器的性能已通过使用 MatLab/Simulink 平台在部分阴影条件下进行测试,并通过软件在环实时数字模拟器 OPAL-RT 5700 进行实验验证。
更新日期:2021-07-03
down
wechat
bug