引用本文: | 陈钦泽,王 文,岳雨霏,等.基于功率补偿量及下垂系数衰减的直流微电网并网转离网无缝切换控制策略[J].电力系统保护与控制,2022,50(16):14-22.[点击复制] |
CHEN Qinze,WANG Wen,YUE Yufei,et al.Seamless switching control strategy of a DC microgrid from grid to off grid based onpower compensation and droop coefficient attenuation[J].Power System Protection and Control,2022,50(16):14-22[点击复制] |
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摘要: |
无缝切换控制策略是保证直流微电网稳定可靠运行的关键。针对传统并网转离网切换控制方法存在母线电压恢复慢、电能质量较差的问题,提出一种基于功率补偿量及下垂系数衰减的直流微电网并网转离网无缝切换控制策略。孤岛检测期间,并网变流器工作在电压控制模式,储能变流器(Energy Storage Converter, ESC)工作在下垂控制模式。通过建模分析,证明采用下垂控制时孤岛检测期间直流母线电压是可控的,由此得到下垂系数选择方法。孤岛检测完成后,以固定函数衰减ESC功率补偿量和下垂系数,实现ESC下垂控制和定电压控制的无缝切换,防止因ESC控制模式的突变而引起直流母线电压波动和ESC电流冲击。讨论了衰减函数的选择方法。仿真结果表明,所提无缝切换控制策略能够有效解决孤岛检测期间直流母线电压不可控的问题,抑制孤岛检测完成后因ESC模式切换时所产生的电流冲击。 |
关键词: 直流微电网 无缝切换 储能变流器 母线电压 冲击电流 |
DOI:DOI: 10.19783/j.cnki.pspc.211351 |
投稿时间:2021-10-07修订日期:2022-01-24 |
基金项目:国家自然科学基金面上项目资助(52077010);长沙市杰出创新青年培养计划项目资助(kq2106043) |
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Seamless switching control strategy of a DC microgrid from grid to off grid based onpower compensation and droop coefficient attenuation |
CHEN Qinze,WANG Wen,YUE Yufei,JIANG Hongwei,TANG Xin,FAN Bishuang,ZENG Xiangjun |
(School of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha 410114, China) |
Abstract: |
A seamless switching control strategy is key to ensuring the stable and reliable operation of a DC microgrid. Such a control strategy for a DC microgrid from grid to off grid based on power compensation and droop coefficient attenuation is presented. This solves the problem of slow bus voltage recovery and poor power quality in traditional switching control methods. During island detection, the grid-connected converter works in the voltage control mode, and the energy storage converter (ESC) works in the droop control mode. Through modeling and analysis, it is proved that the DC bus voltage is controllable during island detection when droop control is used, and thus the selection method of the droop factor is obtained. After the islanding detection is completed, the ESC power compensation and droop coefficients are reduced by the fixed function to achieve a seamless switch of ESC droop control and voltage control. This prevents DC bus voltage fluctuations and ESC current impacts which may occur because of abrupt changes in ESC control mode. The selection method of the attenuation function is discussed. The simulation results show that the proposed seamless handover control strategy can effectively solve the problem of DC bus voltage being uncontrollable during islanding detection, and can suppress the current impact caused by ESC mode switching when islanding detection is completed.
This work is supported by the General Program of National Natural Science Foundation of China (No. 52077010). |
Key words: DC microgrid seamless switching energy storage converter bus voltage impulse current |