基于最优电压矢量的有源滤波器电流控制新方法

A NOVEL CURRENT CONTROL METHOD FOR ACTIVE POWER FILTER BASED ON OPTIMAL VOLTAGE VECTOR

提出了一种新的基于最优电压矢量的有源滤波器滞环电流控制方法。该方法的特点是用一组滞环相间电流比较器和一组阶梯式相间电流比较器相结合，快速、正确地判断有源滤波器参考电压空间矢量所在的区域，并由此决定最优电压矢量及对有源滤波器实行滞环电流控制。用电磁暂态程序进行的计算机仿真结果表明，该方法能快速、正确地确定最优电压矢量，从而可有效地降低开关频率和提高有源滤波器的效率。其突出优点是在参考电压空间矢量变化较快且难以预测的情况下，仍能快速跟踪及确定其所在的区域，从而可有效地减少电流补偿误差，改善有源滤波器的性能。

A novel hysteresis current control method for active power filter based on optimal voltage vector is suggested. The method jointly utilizes two sets of phase current difference comparators to determine the locations of the reference voltage vector and the current error vector. When the system reference voltage vector is changing rapidly and randomly which makes it difficult to estimate its location, the new method can fast detect its correct position by a single try-and-error process which is essential to the performance of active power filter. The related concept and formulation are presented. Computer simulation is conducted on a testing system and the results show that the method can fast determine optimal voltage vector, therefore effectively reduce current tracking error, and in the meanwhile apparently reduce switching frequency of voltage source inverter (VSI) and hence improve efficiency of active power filter noticeably.