High-performance Digital Control of Power Converters

During the implementation of a power converter digital control system, one of the usual main drawbacks is the required programming time which introduces a delay between the system design and simulation and the experimental phase. An effective way to minimize it is achieved by specific tools which automatically generate the needed code for the target platform, hence, for instance, either C code for a microcontroller or HDL code for an FPGA. In this thesis, the Simulink HDL Coder tool effectiveness is validated for the automatic generation of DC/DC and DC/AC power converters digital control systems VHDL codes. In particular, two different high-performance digital average current control systems are designed and simulated on Simulink. Then HDL Coder is used to automatically generate the corresponding VHDL code. At last, the control systems are implemented on an FPGA and their correct operation is experimentally tested on the corresponding power converter. After addressing the main digital average current control issues, a PWM modulator and a current controller are implemented for a four-quadrant DC/DC H-bridge converter. Then, the same system is extended for the current control of a DC/AC three-phase inverter, designing a carrier-based space vector PWM modulator. In both modulation cases, a multisampling double-update strategy is exploited. Moreover, a dSPACE rapid prototyping system is used to provide a visual user interface, where the main reference and control signals can be visualized. As a final application, the digital current control system is adapted to the torque control of a permanent magnet assisted synchronous reluctance motor.