Developing a Robust and Universal Single-phase Three-phase DC/AC Converter with Small-size, Ripple-free DC Side and Harmonic-free AC Side

开发具有小尺寸、无纹波直流侧和无谐波交流侧的鲁棒通用单相三相 DC/AC 转换器

• 批准号: 538617-2019
• 负责人: Karimi, Houshang
• 金额: $ 9.11万
• 依托单位: École Polytechnique de Montréal
• 依托单位国家: 加拿大
• 项目类别: Idea to Innovation
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=693372
• 关键词: Developing; Robust; Universal; Single; phase

Distributed energy resource (DER) units including distributed generators and energy storage systems are being increasingly deployed to improve efficiency, increase reliability, and decrease energy costs. The DER units are often interfaced to the host grid through voltage-sourced converters (VSCs) as they offer high controllability, energy conversion flexibility, and fast dynamic response. Despite their advantages, the VSC-based DERs create certain number of concerns, e.g., power quality and stability degradation, voltage ripples on the VSC dc-side caused by unbalanced grid. The voltage imbalance imposed on the host grid is inevitable due to the presence of single-phase loads/generators, partially transposed transmission lines, etc. The presence of voltage ripples on the dc-side of the VSC causes stress and accelerates the degradation of the capacitor, and reduces its life-time. To reduce the ripples, large electrolytic capacitors are widely used which have a limited life span. The dc ripples can also cause injection of non-characteristic harmonics in the VSC ac-side which in turn lead to additional power loss, malfunctioning of protection systems, transformer saturation, etc. The aim of this project is to develop and prototype a plug-and-play converter for three-phase and single-phase DER systems to tackle the above power quality issues. The central idea is to feed a small, controlled level of unbalanced current in response to the unbalanced grid such that the ripple-free dc-side voltage and harmonic-free ac-side currents are guaranteed. Comparing to the existing VSC technologies, the proposed technology provides the following unique innovative features: (i) Ripple-free dc-side: Increased lifetime, reduced dc capacitor size, more cost competitive, improved stability are thus achieved. (ii) Harmonic-free ac-side current: Reduced power loss, increased power quality, reduced instabilities excited from ac-side grid are guaranteed.

包括分布式发电机和储能系统在内的分布式能源（DER）单元越来越多地得到部署，以提高效率、提高可靠性并降低能源成本。分布式能源单元通常通过电压源转换器 (VSC) 连接到主电网，因为它们提供高可控性、能量转换灵活性和快速动态响应。尽管有其优点，基于 VSC 的 DER 也带来了一些问题，例如电能质量和稳定性下降、电网不平衡引起的 VSC 直流侧电压纹波。由于单相负载/发电机、部分换位输电线路等的存在，主电网上的电压不平衡是不可避免的。VSC 直流侧电压纹波的存在会产生应力并加速电压的退化。电容器，并缩短其使用寿命。为了减少纹波，广泛使用大型电解电容器，但其寿命有限。直流纹波还会导致 VSC 交流侧注入非特征谐波，进而导致额外的功率损耗、保护系统故障、变压器饱和等。该项目的目的是开发并原型化一个插头适用于三相和单相分布式能源系统的即插即用转换器可解决上述电能质量问题。其中心思想是响应不平衡电网馈送一个小的、受控的不平衡电流，从而保证无纹波的直流侧电压和无谐波的交流侧电流。与现有的VSC技术相比，所提出的技术具有以下独特的创新功能：（i）无纹波直流侧：从而实现延长寿命、减小直流电容器尺寸、更具成本竞争力、提高稳定性。 (ii) 无谐波交流侧电流：保证减少功率损耗、提高电能质量、减少交流侧电网激发的不稳定性。