Analysis and Applicability Comparison of Single Current Regulator Methods of PMSM Under Square-Wave Mode

Single current regulator (SCR) control is a popular flux-weakening control for permanent magnet synchronous motor (PMSM), which can maintain the output voltage amplitude constant at the maximum value (suitable for square-wave mode), while providing well dynamic performance. Currently, four kinds of SCR control have been proposed separately from different views. The principle of SCR control is summarized from a novel view in this article. Based on that, another two SCR methods are derived naturally, which is single
q
-axis current regulator-regulates
d
-axis and
q
-axis voltage(SQCR-RDV and SQCR-RQV) methods respectively. More than that, the issue of current regulator structure is discussed in detail. Small signal analysis is adopted to test the system stability while the proper and improper regulators are applied. The influence of the unstable operation is also analyzed by the current locus. Then, appropriate SCR methods are recommended for finite and infinite speed PMSM. The analyses are verified by simulation and experimental results.