消除三相电压不平衡引起的电压源逆变器直流环节电压脉动的控制方法

Control Method for DC-link Voltage Ripple Cancellation in Voltage Source Inverter under Unbalanced Three-phase Voltage Supply Conditions

研究和分析了用于消除电网不平衡时电压源逆变器直流母线脉动电流的补偿控制方法。脉动电流不仅影响传动装置的运行性能,而且降低逆变器的电源品质。控制参数范围的选择取决于变流器抵抗电压不平衡的能力和系统参数。文中讨论和分析了在控制参数范围内控制方法对每相的功率因数和电流幅值的影响,重点分析了功率因数和前端整流器输入端电流不平衡问题,并提供系统在无补偿控制和补偿控制两种状态下的数值仿真和实验测量结果。

A control method for the compensation of unbalanced voltage supply that eliminates pulsating current in the DC bus of a voltage source inverter is investigated and analyzed. Such a pulsating current can have detrimental effects on operating properties of the drive as well as on the quality of power supply in the electrical vicinity of the inverter. A feasible range of control parameters is determined based on the required level of immunity against unbalanced voltage supply and on the parameters of the system. The impact of the control method on the power factors and current amplitudes in individual input phases for the available range of control parameters is analyzed and discussed. In particular, achievable power factor and current unbalance at the input of the front-end rectifier are addressed. Examples of numerical simulations and experimental measurements illustrate operation of the system under investigation, both with and without the use of the compensation method.