Three-Phase Three-Level Shunt APF Control System Based on Multi-Task Parallel MCU

With the development of power electronics technology, the nonlinear and harmonic loads in the power grid are increasing rapidly. The increasingly prominent power quality issues raise the demand for active power filter (APF) sharply. Numerous and accurate sampling signals, timeconsuming harmonic extraction algorithms, and fractional tracking control loop make the APF control system sophisticated and costly. This paper presents the hardware structure and software architecture of a low-cost control system based on the TI dual-core microcontroller unit (MCU) TMS320F28377D for the three-phase three-level shunt APF. The dual-core MCU has the capability to process multiple tasks parallelly. The number of microchips in the control system is significantly reduced by fully utilize various peripherals and rationally arranging the timing of each serialprocessing core. Fewer microchips further simplify the peripheral circuit design, cut down the number of PCB layers, moderate layout design complexity, and improve the development efficiency. The experiments are carried out. The cost, as well as effectiveness comparisons between the control system proposed in this paper and previous control system, are given. The comparison results demonstrate the low-cost characteristics of the proposed control system. In the meanwhile, the results of experiments verify the feasibility of the low-cost control system.