摘要
分析直流配电网电压动态变化过程中电容器储能与旋转电机机械动能之间的能量转换关系,阐述基于虚拟电容的直流电压惯性的定义,提出适用于直流配电网中旋转电机改善电压惯性的控制策略。该控制策略通过引入电压波动信号,分别修正同步电机侧变流器的电流控制以及变速风电机组的功率曲线系数,将2种发电机组的转速与配电网直流电压相互耦合,使2种发电机组均可在系统电压变化过程中释放或吸收旋转动能,并通过模拟电容器充放电过程中的能量变化,为直流电压提供惯性支持。通过建立6端直流配电网仿真系统,验证所提控制策略在系统功率不平衡后,能利用同步发电机和风电机组提供的电压惯性支持,有效地抑制直流电压波动,从而提高系统暂态稳定性。
The energy conversion relationship between the capacitor energy storage and the mechanical kinetic energy of the rotating electrical machine during dynamic variations in voltages of DC distribution networks is analyzed. The definition of DC voltage inertia based on the virtual capacitance is clarified,and the control strategy to improve the rotating motor＇s voltage inertia in DC distribution networks is proposed. By introducing voltage fluctuation signals, the current control of the synchronous generator-side converter and the power curve coefficient of the variable-speed wind turbine are corrected. The rotor speed of the two kinds of generator and the DC voltage of the distribution network are coupled, so that the two kinds of generator can release or absorb rotational kinetic energy when the system voltage varies and provide inertial support for DC voltages based on energy variation simulation of the charging and diseharging of capacitors. A six-terminal DC distribution network simulation system is established,test results on which verify that the proposed control strategy can effectively suppress the DC voltage fluctuations under the unbalanced power by taking advantage of the voltage inertial provided by synchronous generators and wind turbines, which effectively improves the system transient stability.
作者
付媛
黄馨仪
徐岩
白聪聪
FU Yuan;HUANG Xinyi;XU Yan;BAI Congcong(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
2018年第10期32-38,共7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
直流配电网
电压暂态稳定性
旋转电机
虚拟电容
惯性控制
DC distribution network
voltage transient stability
rotating motor
virtual capacitance
inertial control
