摘要
在传统光伏逆变器低电压穿越(LVRT)控制技术的基础上,提出一种根据电压故障类型进行无功功率输出的可实现柔性电压支撑的LVRT控制策略。基于瞬时功率理论,对αβ坐标系下的功率、电流关系进行了分析;基于上述理论分析,提出一种基于电压正、负序分量加权分配的无功补偿策略,该策略根据不同的电压故障类型,通过调整分配因子生成相应的无功电流参考指令来实现提升三相电压有效值、降低公共点电压三相不平衡度等目标的电压支撑功能;在PSCAD/EMTDC仿真平台上进行了三相对称故障、单相短路接地故障和两相短路接地故障的仿真实验,仿真结果验证了所提策略的正确性。
Based on the traditional LVRT（ Low Voltage Ride Through） control technology ot PV （PhotoVoltalc） inverter, an improved LVRT control strategy with flexible voltage support is proposed, in which the output reactive power is based on the voltage fault types. Firstly, the relationship between the power and current in αβ coordinate system is analyzed based on the instantaneous power theory. Subsequently, a reactive power compensation strategy based on the positive- and negative-sequence voltage component assignment is proposed, in which the reactive current reference command can be flexibly adjusted by the assignment factor according to the voltage fault. Conse- quently,voltage support functions of increasing the RMS value of the three-phase voltage and reducing the three- phase voltage imbalance can be achieved. Finally, the simulation experiments of three-phase symmetric fault, single- phase short circuit grounding fault and two-phase short circuit grounding fault are carried out on the PSCAD/ EMTDC simulation platform, and the simulative results verify the correctness of the proposed strategy.
作者
欧阳森
马文杰
OUYANG Sen;MA Wenjie(School of Electric Power,South China University of Technology,Guangzhou 510640,China)
出处
《电力自动化设备》
EI
CSCD
北大核心
2018年第9期21-26,共6页
Electric Power Automation Equipment
基金
广东省自然科学基金资助项目(2016A030313476)~~
关键词
光伏
低电压穿越
逆变器
无功支撑
故障类型
控制策略
photovoltaic
low voltage ride through
electric inverters
reactive power support
fault types
control strategy
