面向舰船综合电力系统的10 kV/2 MW模块化多电平双向直流变换器控制策略  

Control Strategy of 10 kV/2 MW Modular Multilevel Bidirectional DC-DC Converter for Vessel Integrated Power System

作　　者：刘计龙[1] 陈鹏 肖飞[1] 朱志超 黄兆捷 Liu Jilong;Chen Peng;Xiao Fei;Zhu Zhichao;Huang Zhaojie(National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering,Wuhan 430033 China;School of Electrical Engineering Southeast University,Nanjing 210096 China)

机构地区：[1]海军工程大学舰船综合电力技术国防科技重点实验室,武汉430033 [2]东南大学电气工程学院,南京210096

出　　处：《电工技术学报》2023年第4期983-997,共15页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金青年基金资助项目(51807200)。

摘　　要：由于电压等级高、模块化程度高、容错性能好等优势,模块化多电平双向直流变换器(MMBDC)非常适合在下一代舰船综合电力系统(IPS)中充当能量路由器的角色。然而,针对该变换器的控制策略存在端口电流不受控、环路耦合强、低频振荡显著等问题。为了解决上述问题,该文首先,建立构成MMBDC的子变换器数学模型,推导低频谐振点。其次,针对直流多端口模块化多电平子变换器提出基于陷波器的三环解耦控制策略,推导该策略的控制环路解耦特性,对控制框图进行了简化,并比较传统控制策略与所提控制策略的动态特性。最后,设计并制作了10 kV/2 MW级MMBDC工程样机,介绍绝缘设计、控制系统架构、电气柜结构布局等工程实现方法,并进行所提控制策略的满功率实验,验证了该文理论分析研究的有效性。A Modular multilevel bidirectional DC-DC converter(MMBDC) is recommended as the energy router for DC power distribution of the next generation of the integrated power system(IPS) to interconnect the medium-voltage DC(MVDC) bus and the low-voltage DC(LVDC) bus. However, the traditional control strategies for MMBDC have uncontrolled MVDC side currents, highly coupled control loops, and unrestrained low-frequency resonance. It poses the threats of MVDC side overcurrent, the difficulty of designing control parameters, and poor dynamic performance. Therefore, this paper proposes a notch-filter-based triple-loop decoupling control strategy, and the effectiveness is validated through a 10 kV/2 MW engineering prototype.Firstly, the fundamental topology of MMBDC is introduced, which is a cascaded system composed of multi-port modular multilevel DC-DC converter and dual active bridges(DAB). Secondly, the small-signal models of the sub-converters are established. The resonance frequency of MMBDC is derived by solving the transfer function. A generalized state space model is established for DAB to ensure accuracy at the high-frequency band. Thirdly, a triple-loop decoupling control strategy based on a notch filter is proposed, which consists of a double closed-loop control for average sub-module voltage and single closed-loop control for voltage balancing of each sub-module. The MVDC side current is selected as the inner-loop control objective of the average sub-module voltage control to eliminate the overcurrent risk. A notch filter is cascaded in the inner loop to suppress the low-frequency resonance. The control loops are decoupled by restricting the sum of the output of the voltage balancing control loop to 0. The decoupling characteristic and the simplification method of the proposed strategy are derived.Simulations with sinusoidal small-signal inputs of different frequencies are implemented to depict the scatter chart of the frequency-domain characteristics of MMBDC, which is further compared with the theoretical bode

关 键 词：舰船综合电力系统 双向直流变换器 中压直流变换器 解耦控制策略 

分 类 号：TM46[电气工程—电器]