模块化单级式高频隔离型双向升降压谐振式AC-DC功率变换技术研究

AC grid-connected energy storage systems put forward higher and higher requirements on AC-DC converter in aspects of the grid voltage adaptability, efficiency, life time, cost and volume. A novel modular single-stage AC-DC conversion technology well meeting the above requirements is proposed and the following research is carried out in this project. (1) Topology technologies of the novel single-stage low-voltage single & three-phase high-frequency isolated bidirectional buck-boost resonant AC-DC power conversion modules; Fixed-frequency phase-shifted modulation strategy based on three phase-shifted angles which can achieve full range soft-switching and optimization of resonant current characteristics and corresponding control technology; (2) Topology technologies of single & three-phase multi-module series single-stage AC-DC converters based on above novel power conversion module; Seeking of the optimal module series number based on optimization of efficiency, cost and volume; System-level unified closed-loop control technology integrating AC & DC current control and AC voltage balance control of each module; (3) Implementation technologies and its application in the energy storage systems. The proposed power conversion technology has significant advantages of wide grid voltage adaptability, bidirectional buck-boost ability, high efficiency, long life time and high power density. The expected research results will contribute to the improvement of the comprehensive performance of energy storage systems and further promote its large-scale application, which is of important scientific significance and practical value.

交流并网型储能系统对AC-DC功率变换器的电网电压适应性、效率、寿命、成本和体积等方面提出越来越高的要求。项目提出适应上述需求的新型模块化单级式AC-DC功率变换技术，开展如下研究：(1) 低压单、三相新型单级式高频隔离型双向升降压谐振式AC-DC功率变换模块的拓扑、可实现全范围软开关和谐振电流特性优化的定频移相调制策略及控制技术；(2) 基于上述新型功率变换模块的面向中、高压电网的单、三相多模块串联单级式AC-DC功率变换拓扑、基于效率、成本和体积优化的最优模块串联数量寻求、包含交、直流电流控制及各模块交流侧电压均衡控制的系统级统一闭环控制技术；(3) 实用化技术及在储能系统中的应用。所提出的功率变换技术具有宽电网电压适应性、双向升降压、高效率、长寿命、高功率密度等显著优点。研究成果有助于储能系统综合性能的提高进而推进其大规模推广应用，具有重要的科学意义和实用价值。

本项目以面向交流并网型储能系统的AC-DC功率变换技术为研究对象，提出了模块化单级式高频隔离型双向升降压AC-DC功率变换技术，旨在提高系统在电网电压适应性、效率、寿命、成本和体积等方面的综合性能。项目开展并取得了如下创新性成果：(1) 提出了电感储能型准单级式高频隔离型AC-DC功率变换模块的可实现全范围软开关和电流特性优化的三移相角定频移相调制策略及控制技术；(2) 提出了单级式高频隔离型谐振式AC-DC功率变换模块的拓扑及其电流特性优化调制策略；(3) 分别提出了基于上述新型功率变换模块的面向中、高压电网的多模块串联单级式AC-DC功率变换拓扑、包含交、直流电流控制及各模块交流侧电压均衡控制的系统级统一闭环控制技术；(4) 形成了完备的实用化技术并在储能系统中进行了实验验证。.所提出的功率变换技术具有宽电网电压适应性、双向升降压、高效率、长寿命、高功率密度等显著优点，研究成果有助于提高储能系统综合性能，进而推进其大规模推广应用，具有重要的科学意义和实用价值。