Accurate, high bandwidth current control is a requirement for high performance vector controlled AC drives. Synchronous PI current regulators are the preferred solution for this purpose. Design and operation principles of synchronous PI current regulators are well established. However, there are a number of issues that must be considered, especially when the drive must operate at high synchronous frequencies, including regulator design, effects due to discretization and the associated delays, voltage constraints and current sampling issues among other. Inadmissible degradation of the current regulator performance and consequently of the drive can occur otherwise.