光伏电站抑制电网机电振荡的物理机制研究  

Research on the Physical Mechanism of Photovoltaic Power Station to Restrain Grid Electromechanical Oscillation

作　　者：张颖 刘新元 ZHANG Ying;LIU Xinyuan(State Grid Shanxi Electric Power Research Institute,Taiyuan,Shanxi 030001,China)

机构地区：[1]国网山西省电力公司电力科学研究院,山西太原030001

出　　处：《山西电力》2021年第2期10-14,共5页Shanxi Electric Power

摘　　要：通过2个受控电流源来描述光伏在机电时间尺度下的有功、无功功率输出特性,并据此建立了光伏参与机电振荡抑制时的电网有功功率分布模型,利用电气转矩法分析了光伏在振荡抑制模式下影响同步机电系统惯量水平、阻尼能力、同步特性的物理机制及其影响规律。研究结果表明:若光伏系统根据系统机电振荡过程中的转速、频率、功率、功角等特征量的变化趋势来动态地调控其输出的有功、无功功率,则电网的阻尼能力、同步特性、惯量水平将被等效地改变。因此,光伏系统可以根据电网运行需求主动地调控系统的振荡幅值、振荡周期以及振幅的衰减速度。仿真结果验证了光伏系统抑制电网机电振荡机理分析的正确性。Two controlled current sources are used to describe the active and reactive power output characteristics of photovoltaic in electromechanical time scale,and based on this,the active power distribution model of grid is established when photovoltaic participates in electromechanical oscillation restraint.Then,the physical mechanism and law of influence of photovoltaic on the level of inertia,damping capacity and synchronization characteristics of the synchronous machine power system under the oscillation restraint mode is analyzed with the electric torque method.The research results show that,if the photovoltaic system dynamically regulates and controls its output of the active and reactive power according to the change trend of characteristic quantities like revolving speed,frequency,power and angle in the process of system electromechanical oscillation,then the damping capacity,synchronization characteristics and inertia level of the power grid will be changed equivalently.Therefore,the photovoltaic system can actively regulate and control the amplitude of the oscillation,the period of the oscillation and the decay rate of the amplitude of the system according to the requirements of power grid operation.The simulation results verify the correctness of the mechanism analysis of photovoltaic system to restrain grid electromechanical oscillation.

关 键 词：光伏电站 机电振荡 时间尺度特性 阻尼能力 同步特性 惯量水平 

分 类 号：TM712[电气工程—电力系统及自动化]