基于改进直接功率控制的电压暂降耐受能力提升方法

Enhancement method of voltage sag tolerance ability based on improved direct power control

变频器被广泛应用于现代化的工业生产领域,但其对电压暂降非常敏感,常因电压暂降而使转速跌破下限,导致设备跳停,造成较大的经济损失。基于此,提出了基于改进直接功率控制的电压暂降耐受能力提升方法。首先,利用弱励磁电流控制,减小励磁电流参考值,旨在维持转速高水平运行和避免直流端电压过饱和。然后,提出了改进功率参考值计算器,将转速参考值引入有功功率计算中,维持其处于较高水平,并将励磁电流参考值引入无功功率计算中,使其自动减小,从而避免转速跌破下限造成设备跳停。最后,在MATLAB/Simulink平台上搭建了仿真模型,通过算例分析验证了所提方法在提升电压暂降耐受能力方面的有效性和适用性。

Inverters are widely used in modern industrial production fields,but it is very sensitive to voltage sags.It often causes the speed to fall below the lower limit due to voltage sags,resulting in equipment jump and greater economic losses.Based on this,a weak excitation current control is proposed to reduce the excitation current reference value to maintain the high level of speed operation and avoid the oversaturation of DC terminal voltage.Secondly,an improved power reference value calculator is proposed to introduce the speed reference value into the active power calculation to maintain it at a high level,and to introduce the excitation current reference value into the reactive power calculation to reduce it actively,so as to avoid the speed falling below the lower limit and causing the equipment to trip-stop.Finally,a simulation model is constructed on the MATLAB/Simulink platform,and the effectiveness and applicability of the proposed method in improving the voltage dips tolerance ability are verified through the analysis of examples.