摘要
扰动发生后新能源发电和恒功率负荷侧换流器在现有功率控制模式下所表现出的负阻抗特性,会大幅增加直流电压振荡失稳的风险。为此,首先针对直流电压振荡失稳的问题,推导含恒功率负荷两端直流微电网的小扰动线性化状态方程。其次,结合各状态变量的参与因子,选取振荡电流、电压作为可调节控制参数,将其分别引入储能换流器与恒功率负荷换流器的占空比反馈环节中,提出基于状态反馈的多端直流电压振荡控制方法。然后,利用根轨迹、Bode图分析附加状态反馈电压振荡控制技术后的直流微电网稳定裕度的变化规律,为控制参数设计提供依据。最后,搭建时域仿真系统,验证了所提出的控制方法可有效抑制直流微电网的电压振荡,显著提高系统的动态稳定性。
Under the existing power control mode,the negative impedance characteristics of new energy generation and constant power load-side converter after disturbance greatly increase the risk of DC voltage oscillation instability.For that,the small-disturbance linearized state equation of two-terminal DC microgrid with constant power load is firstly derived to solve the problem of DC voltage oscillation instability.Secondly,the oscillation current and voltage are selected as adjustable control parameters by the coordination of par⁃ticipation factors for each state variable,which are introduced into the duty cycle feedback link of energy storage converter and constant power load converter respectively,so that the multi-terminal DC voltage oscillation control method based on state feedback is proposed.Thirdly,the root locus and Bode diagram are used to analyze the variation law of stability margin for DC microgrid with additional state feedback voltage oscillation control technology,which provides the basis for control parameter design.Finally,a time-domain simulation system is built to verify that the proposed control method can effectively suppress the voltage oscillation of DC microgrid and significantly improve the system dynamic stability.
作者
付媛
王耀铎
张祥宇
FU Yuan;WANG Yaoduo;ZHANG Xiangyu(State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Baoding 071003,China)
出处
《电力自动化设备》
EI
CSCD
北大核心
2021年第5期167-174,共8页
Electric Power Automation Equipment
基金
国家自然科学基金资助项目(51607070)
中央高校基本科研业务费专项资金资助项目(2018MS90)。
关键词
直流微电网
电压振荡
参与因子
状态反馈
极点配置
DC microgrid
voltage oscillation
participation factor
state feedback
pole placement
