Highly integrated inverter with multiturn encoder and software-based PFC for low cost applications

Motor control gets more and more common in fields where it was not applicable a few years ago. The prizes for computing power due to higher integration of the power electronics are going down. Because of this, brush-less DC and permanent magnet synchronous machines capture new markets and replace simple grid connected induction machines. The rising standards for electromagnetic interference (EMI) emissions make a power factor correction (PFC) in a lot of applications necessary. In addition a PFC offers some advantages because of the DC bus regulation. In this paper an inverter with a particularly low prize and a high performance is presented. A software based PFC is integrated into the motor control circuit and a low cost absolute position encoder has been developed. In addition some synergetic effect between motor control and PFC will be shown. The experimental results show the feasibility of the integration of a field orientated control with an integrated PFC in one low cost microcontroller.