不对称系统中基于FBD理论的无功电流快速检测方法

Fast reactive current detection based on FBD for unbalanced system

为克服传统FBD法(Fryze-Buchholz-Dpenbrock method)电流检测中低通滤波对检测速度和检测准确性的影响,对不对称系统中线性负载的无功功率检测方法进行研究,提出一种无功电流的快速检测方法。对总平均功率和瞬时总电压均方根与电压及电流正、负序分量瞬时值之间的数学关系进行推导,在对系统电压和电流进行快速序分解的基础上,利用其序分量的瞬时值直接计算总平均功率和瞬时总电压均方根。通过对总平均功率和瞬时总电压均方根的直接计算,取消了传统FBD法无功电流检测中的低通滤波器,简化了检测方法,提高了无功电流的检测速度和检测准确性。该方法适用于三相三线系统中不平衡情况下的线性负载无功电流检测,仿真验证了该检测方法的正确性和可行性。

Based on the study of reactive power current detection for linear load in unbalanced system,a fast reactive current detection method is proposed to avoid the influence of low- pass filter on the detection speed and veracity of traditional FBD （Fryze- Buchholz- Dpenbrock method）- based current detection method. Relationships between the mean value of collective instantaneous power or line voltages collective RMS（Root Mean Square） value and sequence components of line voltages and load currents are deduced. The mean value of collective instantaneous power and line voltages collective RMS value are directly calculated with sequence components of line voltages and load currents,obtained from fast sequence components decomposition,thus low-pass filters in traditional methods omitted. It simplifies detection process and enhances detection speed and veracity,suitable for the linear load reactive current detection in unbalanced three-phase three-wire systems. Simulation results verify its validity and feasibility.