基于DSTATCOM的点焊机无功功率补偿研究

为了更好地解决点焊机负荷引起三相负荷不平衡、系统功率因数低等电能质量问题，提出了基于静止同步补偿器（DSTATCOM）的无功功率补偿方法。首先给出了配电静止同步补偿器的主电路结构，然后利用改进的基于瞬时无功理论的电流检测方法检测出谐波和无功电流，分析了配电静止同步补偿器平衡三相不平衡负荷的原理。最后根据点焊机在实际工作中的情况，通过Matlab/Simulink仿真验证了采用的补偿方法可以平衡三相电流，提高系统功率因数和缓解电压跌落。该研究表明用于不平衡负荷的配电静止同步补偿器具有良好的动态性能和静态补偿效果。

Research of spot welding reactive compensation based on DSTATCOM

In order to better solve power quality problems caused by spot welder load such as three-phase unbalanced load and low system power factor, a reactive power compensation method based on static synchronous compensator (DSTATCOM) is proposed. The structure of main circuit of DSTATCOM is provided firstly, and then an improved current detection method based on the instantaneous power theory is presented, which can detect harmonic and reactive current. Subsequently, the principle of balancing unbalanced three phase load using DSTATCOM is analyzed. According to the actual working conditions of spot welding, simulation is done, which shows the proposed method can balance three-phase currents, improve system power factor and reduce voltage sags, and also proves that DSTATCOM has good dynamic and static compensation performance.