高压直挂储能功率变换技术与世界首例应用

Transformerless High-voltage Power Conversion System for Battery Energy Storage System and the First Demonstration Application in World

从拓扑、控制、设计、实验验证到工程应用,全面论证与评估无变压器直挂电网的链式储能功率变换关键技术问题。提出应对电网电压不平衡、模块故障以及相间电池组均衡的统一零序电压算法及综合集成控制策略,探讨模块间共模电流抑制及电池侧二次脉动电流的平抑问题,研发3相、每相20链节的低压模拟样机,对控制策略进行了全面验证。提出链式储能功率变换系统的优化设计方法,设计并研发了10kV/2MW/2MW×h的大容量链式储能功率变换系统,在国家863计划的支持下,于2014年在深圳宝清储能电站进行了世界首例工程示范应用,目前已经安全运行4年,积累了丰富的运行数据与经验,为链式储能功率变换技术的推广应用奠定了基础。

Comprehensive argumentation and evaluation of the key issues of the transformerless cascaded H-bridge converter applied in battery energy storage system(BESS)were performed from the aspects of topology,control,and design and experiment verification.A unified balance control scheme was proposed in this paper,which reduced the complexity of the whole control scheme and integrates the control under unbalanced grid voltage,module fault-tolerant control and interphase state of charge(SOC)balancing control together.In order to verify the feasibility of the proposed control scheme,a downscaled experimental prototype was built up in the laboratory.The suppression of common-mode current among modules and the second-order rippled current of the battery were discussed in detail.Then,the optimal design method of the cascaded H-bridge converter for BESS was proposed.We have designed a 10 k V/2 MW/2 MW×h battery energy storage system based on cascaded H-bridge converter(CHBC-BESS).Supported by the national high technology research and development of China 863 program,the first practical engineering demonstration application was performed at the Baoqing energy storage power station in Shenzhen in 2014.We has accumulated rich experience and operating data in practice,which lays a foundation for the promotion and application of CHBC-BESS.