基于二端口阻抗模型的ES越限失效机理分析与控制方法

Mechanism analysis and control method of electric spring off-limit failure based on two-port impedance model

电力弹簧(ES)对大量可再生能源发电并网引起的电压波动具有抑制作用,但其只能在一个确定的系统电压波动范围内工作,当系统电压波动较大时,ES存在越限失效的风险。因此文中首先分析了ES的稳态运行范围以及越限失效机理;其次分析了关键负载目标电压值变化对ES运行范围的影响;然后基于ES的二端口阻抗模型,提出一种系统电压越限后关键负载目标电压计算方法,优化系统电压越限后的关键负载目标电压,有效扩大ES的运行范围;最后搭建了三相ES仿真模型,验证了所提方法处理ES越限问题的有效性。

Electric spring(ES)can suppress the voltage fluctuation caused by large-scale grid-connected renewable energy sources.However,ES can only work within a certain range of gird voltage fluctuations.This means,if the grid voltage fluctuates greatly,the ES will expose to the risk of off-limit failure.Focusing on this problem,the steady-state operating range and the failure mechanism of ES are analyzed.Then the influence of changes in critical load target voltage on the operating range of ES is analyzed.After that,a calculation method for critical load target voltage based on a two-port impedance model of ES is proposed,which can expand the operation range of the ES through optimal adjustment of the critical load target voltage effectively.Finally,a simulation model of the three-phase ES is built,and the detailed simulation results verify the validity of the proposed method.