一种改进的FBD指令电流检测方法研究

在有源滤波器设计中,指令电流的检测是控制与补偿的关键技术环节。在三相电压不对称情况下,由于a相电压与其正序电压之间存在相位差,使传统FBD检测法在提取指令电流时存在误差,针对此不足提出一种改进的FBD检测法,该方法通过瞬时对称分量法检测电网电压基波正序分量的相位,减小了因三相电压不对称而导致的检测误差,同时引入电流平均值理论提取等效电导的直流分量,提高了指令电流检测的动态响应能力。仿真结果表明,基于改进FBD法的有源滤波器能够快速准确地检测和补偿三相不对称系统中的谐波和无功电流。

Improved Directive Current Detecting Method Based on FBD

The detection of directive current is very important for APF. Because of the phase difference between a phase voltage and its positive sequence voltage in the three-phase asymmetry system, the directive current can not be detected accurately by traditional FBD method. An improved FBD detecting method was proposed, the improved FBD acquires the phase of the fundamental positive-sequence voltage by instantaneous symmetrical components, which reduces detection error caused by the three-phase voltage asymmetry, and introduces mean value theory to extract the linear part of equivalent conductance, so as to improve dynamic response capability of directive current detection. The simulation results verify that the APF based on the improved FBD can effectively detect and compensate harmonic and reactive current in the three-phase asymmetrical system.