A surface-mounted permanent magnet synchronous machine drive 10 and a method 30 of controlling the machine drive. Flux weakening and current regulating loops 70, 60 cooperate to provide automatic transition to the flux weakening mode (operation above base speed), regardless of DC bus voltage, load or other operating conditions. This feature provides significant performance improvement. No look-up tables are used in the flux weakening loop. The on-set point for flux weakening is automatically adjusted, and may be changed through software. An appropriate d-axis current component is injected over the entire speed range, providing the maximum available torque (which corresponds to the q-axis current component). The control method works with fixed frequency current compensators.