High power density medium voltage photovoltaic grid-forming inverter with soft-switching

高功率密度软开关中压光伏并网逆变器

• 批准号: 578504-2022
• 负责人: Lam, JohnChiWoJCW
• 金额: $ 2.19万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=752406
• 关键词: power; density; medium; voltage; photovoltaic

The total installed photovoltaic (PV) capacity in Canada has reached to 2.4 GW in 2021, and it is projected to increase to almost 5 GW by 2040. To facilitate large-scale power conversion to electricity from PV energy, the power transmission network consists of a medium voltage (MV) AC grid that collects power from individual PV arrays. As the output voltage of the PV arrays is too low (e.g. 300-750V output) for effective long-distance power transmission, a line frequency (i.e. 60Hz) MV step-up transformer (such as the liquid-filled pad mount power transformer) is used to step up the output voltage to the MV level (> 20 kV). These step-up transformers, however, are bulky and heavy. Collaborating with Northern Transformer Corporation (NT), the goal of the proposed research partnership is to develop a fully integrated high power density PV step-up grid-forming inverter. In particular, a new multi-level based inverter topology that exhibits lossless switching characteristics over the entire power range will be investigated. The developed grid-forming control scheme will allow the proposed inverter topology to emulate as a virtual synchronous generation unit in the power grid, such that the devised topology will be able to: (1) provide fault-ride through capability to maintain normal unit operation during a voltage sag resulted from the grid faults; (2) provide grid frequency regulation to ensure system stability; (3) support seamless transition between grid-connected and islanded modes; and (4) perform output over current protection. NT is a leading manufacturer of liquid-filled power transformers in Ontario, it serves clients such as: Hydro One, Fortis, Toronto Hydro, Alectra, etc. With the significant reduction in size and weight of the proposed PV step-up inversion technology, it will be an ideal replacement for the conventional pad mounted step-up transformer used for PV energy conversion in the MV power grid. Successful development of the proposed transformer-less, step-up grid-forming power technology will provide NT a unique marketing opportunity to create revenue and capitalize on state-of-the-art power solutions for the global PV energy market.

2021 年，加拿大光伏 (PV) 总装机容量已达到 2.4 吉瓦，预计到 2040 年将增加到近 5 吉瓦。为了促进大规模的光伏能源转换为电力，输电网络包括从各个光伏阵列收集电力的中压 (MV) 交流电网。 由于光伏阵列的输出电压太低（如300-750V输出），无法有效进行长距离电力传输，因此需要采用工频（即60Hz）中压升压变压器（如充液式座装电力变压器）用于将输出电压升高至 MV 电平 (> 20 kV)。 然而，这些升压变压器体积大且重。 与北方变压器公司 (NT) 合作，拟议研究合作伙伴关系的目标是开发完全集成的高功率密度光伏升压并网逆变器。 特别是，我们将研究一种新的基于多电平的逆变器拓扑，该拓扑在整个功率范围内表现出无损开关特性。 所开发的并网控制方案将允许所提出的逆变器拓扑仿真为电网中的虚拟同步发电单元，使得所设计的拓扑将能够：（1）提供故障穿越能力以维持正常单元运行电网故障导致电压暂降期间； (2)提供电网频率调节，保证系统稳定； （3）支持并网与孤岛模式无缝过渡； (4)进行输出过流保护。 NT是安大略省领先的液体填充电力变压器制造商，其服务的客户包括：Hydro One、Fortis、Toronto Hydro、Alectra等。随着拟议的光伏升压逆变技术的尺寸和重量的显着减小，它将成为中压电网中用于光伏能量转换的传统垫式升压变压器的理想替代品。 所提议的无变压器升压并网电力技术的成功开发将为 NT 提供独特的营销机会，为全球光伏能源市场创造收入并利用最先进的电力解决方案。