Design Of A Programmable SPWM Inverter Controller Based On FPGA

Nowadays, DC-AC inverters with Sinusoid Pulse Width Modulation (SPWM) techniques are widely used in electric power, postal, telecommunications, aerospace and other fields. Along with the continuous development and popularity of computer technology, SPWM inverters will be applied in much more occasions. The SPWM controllers, which regulate the voltage and frequency by adjusting the SPWM signals, are the core of the inverters. The performance of the controller, directly determines the performance of the inverter. Thus, the key to the design of the controller is how to generate precise and programmable SPWM signals.A design method of FPGA-based SPWM inverter controller is proposed in this thesis. Detailed RTL-level design of this controller is carried out on Altera Quartusâ…¡software, with the top-to-down approach. The SPWM inverter controller is comprised of seven functional modules, which are easy to transplant and upgrade. Therefore the whole control system can be upgraded easily. After the RTL level design is completed, simulation is made on every module and the whole controller. Finally, the design is downloaded to EP2C5Q208C8N chip at the FPGA kit, in order to verify the system function of the controller. The SPWM controller desiged with this method has advantages of output pulse is precise and programmable, frequency and amplitude can be adjusted on line, the dead-time can be preset, and the output voltage can be regulated in a closed feedback loop and so on.A prototype of full-bridge structured inverter power supply is manufactured based on the above SPWM inverter controller. The driving, sampling, filting and protecting circuits are designed in detail. Experiments are made on the protype in conditions of a voltage closed loop. The experimental results prove the feasibility of the proposed method.