The latest C2000 Delfino™ family of microcontrollers supports fast current loop (FCL) implementation for high bandwidth control of motor drives over a wide speed range in high end multi axes industrial servo control applications. Due to the stringent computational demands of the control algorithm and the demands of interfacing to various position feedback sensors used in these applications, traditionally FPGAs and discrete ADCs have been widely used to implement the core control solution. However, recent C2000 MCUs can cost effectively replace FPGAs and external ADCs in these applications and exceed the functional requirements due to superior features.
This technical brief analyses the functional behavior of the servo loops using fast current loop algorithms in terms of bandwidth and phase margin. The test bench consists of a motor-generator set (2MTR-DYNO), an F28379D launch pad (LAUNCHXL-F28379D) and TI’s low voltage GaN inverter modules (BOOSTXL-3PHGANINV). The results show a three times improvement in current loop bandwidth for a given phase margin.