Design and Implementation of a Single-Phase Bipolar SPWM Inverter Power Supply Based on STM32

Abstract

We designed a single-phase bipolar SPWM digitally controlled inverter power supply based on STM32. It uses the STM32 microcontroller as the main controller to output the SPWM pulse. We achieved DC-AC conversion through the full-bridge inverter circuit and obtained the final output voltage waveform through the filter circuit. The A/D detection circuit can detect the effective value of output current and voltage in real time. The sampling circuit is electrically isolated from the output of the inverter circuit, which improves the safety factor. We used STM32 software programming to achieve input undervoltage protection and output overcurrent protection. Besides, we also added the display module and the keyboard module. After adding a 10Ω load, the system can output a stable sine wave with an error of less than 1% and an efficiency of 94.40%. This system has the character of digitally controlled, friendly human-computer interaction and high efficiency.