Bit-Stream control of three phase reversible rectifiers

Bit-stream is a new technique for controlling power electronics applications by interconnecting appropriate control elements inside an FPGA. This paper presents a Bit-Stream based controller for a three phase, 400 V / 7 kVA reversible rectifier, which is used to transfer power between an AC line and a DC bus in a controlled manner. The proposed controller is based on vector control techniques, which provide independent control of the real and reactive power flow through the rectifier, and is the first Bit-stream based vector controller to be reported in literature. The controller is implemented by interconnecting Bit-Stream controller blocks, which implement Clarke and Park´s Transformations, phase locked loops, current controllers and space vector modulation. Simulations using Matlab / Simulink and ModelSim show that the controller successfully manages the power flow through the rectifier, and is not disturbed by sudden changes in the AC line voltage. The inherently parallel nature of Bit-Stream control systems ensures that the addition of extra functionality to the controller will not affect system performance, whereas microprocessor based systems may reach execution time limits as control complexity increases.