不平衡电压下光伏并网节能发电维稳调控方法研究

Research on Stability Maintenance and Control Methods of Photovoltaic Grid-Connected Energy-Saving Power Generation under Unbalanced Voltage

中文关键词:不平衡电压  光伏并网  节能发电  维稳调控

keywords:unbalanced voltage  PV grid connection  energy-saving power generation  stability maintenance control

中文摘要:维稳调控方法不能对光伏并网节能发电具有的非线性、不确定性等进行有效补偿，导致电网电压调节过程中出现超调现象，影响电网发电质量。设计一种基于电压定向的并网节能发电维稳调控方法。根据光伏并网系统的工作原理，建立光伏电池的等效电路和数学模型，分析输出电压、电流的关系；基于电压定向对逆变器和电容器进行控制，获取调控流程，根据直流侧电压和输出功率之间的关系来设计接入位置，保证电网运行过程中的电压稳定。实验结果表明：所设计调控方法的算例的三相电压未出现超调点，均在允许范围内，且光伏消纳率较高。

Abstract:Existing stability maintenance and regulation methods fail to effectively compensate for the nonlinearity， uncertainty， and other characteristics of grid-connected photovoltaic （PV） energy-saving power generation. This leads to overshoot phenomena during power grid voltage regulation， which impairs the power generation quality of the grid. To address this issue， this paper designs a stability maintenance and regulation method for grid-connected PV energy-saving power generation based on voltage orientation. First， according to the working principle of the grid-connected PV system， an equivalent circuit and a mathematical model of the PV cell are established to analyze the relationship between the output voltage and current. Second， the inverter and capacitor are controlled based on voltage orientation to obtain the regulation process. The connection position is designed according to the relationship between the DC-side voltage and output power， so as to ensure voltage stability during the operation of the power grid. Experimental results show that the three-phase voltage in the case study of the designed regulation method has no overshoot points and all values are within the allowable range， with a relatively high PV accommodation rate.