面向光储联合供电系统的高能效多端口DC/AC变换器关键技术研究

As the penetration of photovoltaic (PV) generation increases, the random and fluctuant characteristics of its power generation will affect the stability of the power system. PV together with battery energy storage system (BESS) is an effective method to smooth the fluctuation of PV power, and also improve the utilization of PV generation. Therefore, PV/BESS hybrid systems will be an important development direction of the power system in the future. However, how to realize the high-efficiency, low-cost, flexible and reliable power conversion in PV/BESS hybrid systems is an important issue to be further researched and developed. This project aims to investigate a novel multi-port DC/AC converter based architecture and its key technologies. The main research contents of this project include: 1) Investigation of both topology derivation and circuit design methods of the multi-port DC/AC converter; 2) Development of the optimal power dispatching control and modulation strategies to achieve maximum system efficiency; 3) Study of the modular parallel technology of multi-port DC/AC converters. The key problems of power sharing and zero-sequence circulating current suppression will be deeply investigated. Based on the above work, a whole set of multi-port DC/AC converter based solution, which features high efficiency, high power density, high reliability and low cost, will be achieved for PV/BESS hybrid systems. This will significantly promote the development of multi-energy complementary power generation technologies.

随着光伏发电渗透率不断提高，其发电功率的随机性和波动性将影响电力系统的稳定运行。光储联合供电作为一种平滑光伏功率波动、提升光伏发电利用率的有效手段，成为未来能源电力系统的一个重要发展方向。如何实现光储联合供电系统中高效经济、灵活可靠的电能变换，是亟待研究的重要课题。本项目面向光储联合供电系统，研究一种新颖的多端口DC/AC变换器系统架构及其关键技术，包括：1）研究多端口DC/AC变换器的拓扑构造和电路设计方法；2)探索优化的功率调度控制和调制策略，以实现系统效率最优；3)研究多端口DC/AC变换器模块化并联技术，着重解决并联均流和零序环流抑制关键问题。研究成果将形成一整套面向光储联合供电系统应用的高效率、高功率密度、高可靠性、低成本的多端口DC/AC变换器系统解决方案，有力地促进多能互补发电技术的发展。

光储联合供电是提高光伏发电利用率、实现负荷侧持续平稳供电的重要措施。本项目将集成化多端口功率变换的思想应用于光储联合供电系统，以期提高系统效率、降低系统成本。本项目的主要研究内容包括：1)多端口DC/AC变换器MPC电路拓扑构造和电路设计方法；2)实现“最大化效率”功率调度的控制和调制策略；3)基于MPC的电能质量控制技术；4)MPC模块化并联系统及其均流和零序环流抑制策略。.本项目取得的主要研究成果包括：1)提出了MPC拓扑及其灵活功率控制策略;2)提出了一种MPC与差分功率DC/DC变换器DPPC相结合的新型光储联合供电系统架构，相比传统方案，最高提升效率约2%；3)提出了基于MPC的系列电能质量控制器，实现了有功功率的高能效传输和电能质量的综合治理，且降低了系统成本；4)提出了MPC模块化并联系统及其并联均流和零序环流抑制策略；5)研制了一台高性能的基于MPC的光储联合供电系统样机。.通过上述研究工作，实现了一整套面向光储联合供电系统应用的高效率、高功率密度、高可靠性、低成本的多端口DC/AC变换器系统解决方案，有望应用于双碳目标下的新型电力系统中，同时也丰富和完善了电力电子学多端口功率变换理论和方法。