A novel current control method for active power filter based on optimal voltage vector

Abstract

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.

提出了一種新的基于最優電壓矢量的有源濾波器滯環電流控制方法。該方法的特點是用一組滯環相間電流比較器和一組階梯式相間電流比較器相結合，快速、正確地判斷有源濾波器參考電壓空間矢量所在的區域，并由此決定最優電壓矢量及對有源濾波器實行滯環電流控制。用電磁暫態程序進行的計算機仿真結果表明，該方法能快速、正確地確定最優電壓矢量，從而可有效地降低開關頻率和提高有源濾波器的效率。其突出優點是在參考電壓空間矢量變化較快且難以預測的情況下，仍能快速跟蹤及確定其所在的區域，從而可有效地減少電流補償誤差，改善有源濾波器的性能。