摘要
针对直流微电网惯性低、母线电压质量较差的问题,考虑当前分布式微源对高升/降压比、电气隔离以及高效率变换器的急切需求,提出一种多端口隔离型DC-DC变换器(MPIC)的改进虚拟电容(IVC)控制策略。首先,采用MPIC取代传统的Buck-Boost电路,实现储能系统内部微源相互电气隔离;其次,通过类比交流微电网中虚拟同步电机的调频控制,得到适用于MPIC的IVC控制;然后,建立其IVC控制下储能接口变换器(ESC)的小信号模型,深入分析负载扰动下直流母线电压的动态特性,针对扰动过程中产生的电压过冲现象,采用前馈补偿予以消除,并给出电压跟踪系数、虚拟电容和阻尼系数等参量的整定方法;最后,仿真和实验结果验证了所提控制策略的有效性和正确性。
At present,distributed micro-source has urgent demand for high up/down ratio,electrical isolation and high efficiency converter.Aiming at the low inertia of DC microgrid and poor bus voltage quality,an improved virtual capacitor(IVC)control strategy for a multi-port isolated DC-DC converter(MPIC)is proposed.Firstly,MPIC is used to replace the traditional Buck-Boost circuit to achieve the electrical isolation of the micro sources inside the energy storage system.Secondly,through analog frequency modulation control of the virtual synchronous generator in the AC microgrid,IVC control suitable for MPIC is obtained.Then a small signal model of the energy storage interface converter(ESC)under its IVC control is established,and the dynamic characteristics of the DC bus voltage under load disturbance are analyzed in depth.The voltage overshoot phenomenon generated during the disturbance process is eliminated by feedforward compensation,and the parameters such as voltage tracking coefficient,virtual capacitance and damping coefficient are given.Finally,simulation and experimental results verify the proposed control strategy.
作者
张辉
梁誉馨
孙凯
陈欢
杜明桥
Zhang Hui;Liang Yuxin;Sun Kai;Chen Huan;Du Mingqiao(School of Electrical Engineering Xi’an University of Technology,Xi’an 710048 China;State Key Laboratory of Safety Control and Simulation of Power System and Power Generation Equipment Tsinghua University,Beijing 100084 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2021年第2期292-304,共13页
Transactions of China Electrotechnical Society
基金
国家自然科学基金面上项目(51877117,51877175)
陕西省重点研发计划资助项目(2017ZDXM-GY-003)
陕西省自然科学基金项目(2017JM5100)
台达电力电子科教发展计划重大项目(DREM2019005)
电力系统及发电设备控制与仿真国家重点实验室(SKLD18M06)资助。
