FPGA controlled dual buck half bridge three-level inverter

Multi-level inverters (MLI) have been attracting great attention in renewable energy sources. This paper proposes a novel multilevel inverter: dual buck half bridge three-level inverter (DBHBTLI). The topology of the inverter is based on dual buck half bridge inverter (DBHBI), and cherishes the merits of no shoot-through problem, no body diode reverse-recovery problem, and current half-period work mode, which promote the reliability and efficiency of the system and reduce the losses. The scheme is manipulated by field-programmable gate array (FPGA). Compared with DSP and other dedicated microcontrollers, FPGA has its own advantages in the application of inverter, such as higher speed, more configurable logic resources and peripheral devices. The FPGA controller consists of six main sections: the sine wave generator, the triangle wave generator, the voltage proportion integration (PI) module, the current proportion (P) module, sinusoidal pulse width modulation (SPWM) module, and SPWM distribution module. The FPGA control strategy adopts two-loop system: the voltage proportion integration (PI) module, the current proportion (P) module, as mentioned above. The specific design of controller is introduced in detail where VHDL is used in the design of each module. To test the scheme, the software of SABER is used to simulate the topology in the no load and full load conditions, respectively. In the end, a experimental prototype of 1000W is built in the laboratory to verify the actual performance of DBHBTLI. Theoretical analysis, simulation and experiment on DBHBTLI, which controlled by FPGA, verify the feasibility of the new topology.