Simplification of the Acquisition System for Sensored Vector Control using Resolver Sensor based on FDM and Current Synchronous Sampling

Abstract

Simplification in the acquisition system allows increasing the robustness and the sampling frequency of a motor drive system. Frequency domain multiplexing (FDM) allows reducing the number of signals to be digitized in vector control, simplifying the analog-to-digital system in a motor drive. Nonetheless, the required demultiplexing process is still an open question. This paper proposes a simple demultiplexing technique based on synchronous current sampling. The triangular carrier used in modulation and the resolver excitation signal are synchronized, so that the valley of the carrier happens when the resolver outputs are equal to zero. Thus, the demultiplexed current signals are equal to the samples obtained through synchronous current sampling, eliminating the harmonics in the current signals. The estimated current signals and an angle tracking observer are used to estimate the angular position without the previous demultiplexing of the resolver output signals. Simulation and experimental results show that the demultiplexing process has high accuracy, rejecting the current harmonics and gives a good estimation of the angular position.