摘要：交流电机驱动器的电流检测单元在精度、响应、集成度、隔离性等方面提出了诸多要求，本文设计了一种新型的电流检测方案，采用温度稳定性好、精度高的集成芯片来实现，以克服分立元件空间占用大、温漂明显、精度低、抗干扰能力弱等缺点。该方案通过霍尔电流传感芯片实现高集成度的电流隔离检测，再经低通滤波器滤去高频电流分量后由高精度的A/D采样模块实现电流的过采样，最终由控制芯片实现数字滤波得到电流采样值。整个过程进行实时过流保护，以确保安全性。实验结果表明，该电流检测方案线性度好、安全性高，为交流电机驱动器的电流检测提供了可靠保证。
关键词：电流检测；交流电机驱动器；过采样；霍尔电流传感芯片
Abstract: Aiming at the requirements of high accuracy, quick response, high integration and good isolation for AC motor drives, a novel current detection scheme was designed. It employed integrated chips with good temperature stability and high precision, overcoming the problems of discrete components, such as large footprint, serious temperature drift, low precision and weak antiinterference. After highly integrated and isolated current sensing by a Halleffect chip, filtering by a lowpass filter, and then oversampling by an accurate A/D converter module, the current was finally measured and further processed with digital filtering. Moreover, the whole process was in realtime overcurrent protection. Experimental results show that the designed current detection scheme has good linearity and excellent security, providing a reliable solution for AC motor drives.
Key words: current detection; AC motor drive; over ampling; Halleffect current sensing chip