中压兆瓦级电网模拟器电压采样影响及改进策略  

Voltage Sampling Influence and Improvement Strategy of Medium Voltage Megawatt Power Grid Simulator

作　　者：孙勇 苏建徽[1] 赖纪东[1] 王庆发 董磊[1,2] SUN Yong;SU Jianhui;LAI Jidong;WANG Qingfa;DONG Lei(The Ministry of Education Photovoltaic System Engineering Research Center,Hefei University of Technology,Hefei 230009;Changzhou Sino Sea Electric Power Technology Co.,Ltd.,Changzhou 213001)

机构地区：[1]合肥工业大学光伏系统教育工程研究中心,合肥230009 [2]常州中海电力科技有限公司,常州213001

出　　处：《电气工程学报》2021年第4期205-212,共8页Journal of Electrical Engineering

基　　金：中央科研基本业务支持资助项目(PA2020GDGP0053)。

摘　　要：为测试光伏电站、风电机组以及储能电站等兆瓦级、中压直挂式并网发电系统的电网适应性能力,介绍一种35 kV/3 MW电网模拟器拓扑。然而,受电压互感器(Potential transformer,PT)采样精度限制,直接采用PT输出信号作为电压调节器反馈,会严重降低系统的控制带宽,影响系统输出电压的动、稳态性能。根据PT特性进行频域建模,分析PT采样对系统控制的影响,并提出一种改进的控制策略,将PT输出电压作为有效值环反馈来保证稳态精度,同时增加高带宽低压瞬时值采样控制来跟踪电压指令,以使电网模拟器的输出特性满足要求。35 kV/3 MW电网模拟器的试验样机验证了该控制方案的可行性和正确性。In order to test the grid adaptability of MW-level and medium voltage direct-connected grid connected power generation systems such as photovoltaic power station,wind turbine and pumped storage plant,a 35 kV/3 MW grid simulator topology is introduced.However,limited by the sampling accuracy of potential transformer(PT),the direct use of PT output signal as the feedback of voltage regulator will seriously reduce the control bandwidth of the system and affect the dynamic and steady-state performance of the system output voltage.The frequency domain modeling is carried out according to the characteristics of PT,the influence of PT sampling on the system control is analyzed,and an improved control strategy is proposed.The output voltage of PT is used as the feedback of the effective value loop to ensure the steady-state accuracy.At the same time,the high-bandwidth and low-voltage instantaneous value sampling control is added to track the voltage command,so that the output characteristics of the power grid simulator can meet the requirements.The experimental prototype of 35 kV/3 MW power grid simulator verifies the feasibility and correctness of the control scheme.

关 键 词：中压电网模拟器 电压互感器 低压瞬时值反馈 电压有效值反馈 

分 类 号：TM464[电气工程—电器]