针对电网电压不平衡下电流平衡及功率恒定问题,提出改进型光储虚拟同步发电机(virtual synchronous generator,VSG)控制策略,该策略通过引入虚拟阻抗技术和双二阶广义积分器(double second order generalized integrator,DSOGI)实现正负序分量的有效分离,并基于瞬时功率理论优化电流和功率的协调控制,显著提高了系统在不平衡电网条件下的电流平衡性和功率稳定性.首先,构建基于电机瞬态模型的光伏储能VSG系统的数学模型,以深入理解和模拟VSG在实际电网中的动态行为.通过应用双二阶广义积分器技术,实现了正序与负序分量的有效分离,并基于瞬时功率理论和负序虚拟复阻抗技术,进一步实现电流和功率的协调控制,确保电流平衡及功率恒定.最后,利用MATLA/Simulink软件构建仿真模型,模拟光伏储能系统在不平衡电网状态下的运行情况,仿真结果表明所提控制策略显著提高了控制策略的精度和响应速度,可确保动态电网环境中的操作效率和可靠性.
Improved VSG Control Strategy for Photovoltaic-storage Systems Under Grid Voltage Imbalance
To solve the problem of current balance and constant power under unbalance of power grid voltage,this study proposesan improved optical storage virtual synchronous generator(VSG)control strategy,which realizes effective separation of positive and negative sequence components by introducing virtual impedance technology and double second-order generalized integrator(DSOGI).This strategy optimizes the coordinated control of current and power based on instantaneous power theory,thus significantly improving the current balance and power stability of the system under unbalanced network conditions.Firstly,this study constructs a mathematical model of PV energy storage VSG system based on motor transient model in order to deeply understand and simulate the dynamic behavior of VSG in the actual power grid.By using the double seconf-order generalized integrator technology,effective separation of positive and negative components is realized.Based on the instantaneous power theory and the negative sequence virtual complex impedance technology,the current and power can be coordinated to ensure the current balance and constant power.Finally,MATLAB/Simulink software is used to build a simulation model to simulate the operation of the photovoltaic energy storage system in the unbalanced power grid state.The simulation results verify that the proposed control strategy significantly improves the precision and response speed of the control strategy,and ensures the operational efficiency and reliability in the dynamic power grid environment.
energy storage systemunbalanced power gridvirtual synchronous motorsequential controlpower fluctuation
万方数据
维普
