摘要
随着高比例新能源电力系统的发展,系统等效转动惯量大幅下降,电网发生故障时,系统频率稳定问题愈发凸显。然而新能源电源传统的低穿控制策略仅考虑电压支撑需求,并未考虑大面积风电机组低穿成功造成的暂态低频问题。基于此,该文提出一种综合考虑电压与频率变化量的自适应低电压故障穿越控制策略。该控制策略通过构建电压与频率变化量指标并比较二者大小实现低电压故障穿越控制策略切换。当电压指标小于频率指标时,切换至有功功率优先模式,通过调整有功电流参考值,增大风机有功功率输出,从而有效缓解传统低穿策略下高比例新能源系统的暂态低频问题;反之,则选择无功功率优先模式,增大风机无功功率输出,以支撑系统电压。与传统低穿控制策略相比,新策略可以兼顾故障期间调压与调频需求,提升风电并网系统的稳定性。最后通过MATLAB/Simulink验证了所提控制策略的有效性。
With the development of high proportion new energy power system,the equivalent moment of inertia of the system decreases greatly.When the fault occurs,the problem of system frequency stability becomes more prominent.However,the traditional low voltage ride-through(LVRT) control strategy of new energy power supply only focuses on the demand of voltage support without considering the transient low-frequency problem caused by the success of LVRT of large-area wind turbines.Based on this,this paper proposes an adaptive LVRT control strategy considering the voltage and frequency variation.The control strategy realizes the switch of the LVRT control strategies by constructing the voltage and frequency variation indexes and comparing them.When the voltage index is less than the frequency index,the active power priority mode is switched to.The active power output of the DFIG is increased by adjusting the active current reference value so as to effectively alleviate the transient low frequency problem of the high proportion of new energy system under the traditional low voltage ride-through strategy.Otherwise,the reactive power priority mode is selected to increase the fan’s reactive power output to support the system voltage.Compared with the traditional LVRT,the new adaptive LVRT control strategy takes into account the demand of both the voltage and frequency regulations during the faults,improving the stability of the wind power grid-connected system.Finally,the effectiveness of the proposed control strategy is verified by the Matlab/Simulink.
作者
郑涛
邹芃蓥
颜景娴
王子鸣
ZHENG Tao;ZOU Pengying;YAN Jingxian;WANG Ziming(State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China;State Grid Economic Technology Research Institute Co.,Ltd.,Changping District,Beijing 102200,China)
出处
《电网技术》
EI
CSCD
北大核心
2022年第12期4666-4675,共10页
Power System Technology
基金
国家自然科学基金联合基金项目(批准号:U2166205)。
