基于STM32的单相逆变器并网系统设计与实现
Design and Implementation of Single-Phase Inverter Grid-Connected System Based on STM32

本设计采用STM32单片机作为主控芯片，采用双极性SPWM调制方法，以单相全桥逆变电路为核心电路，实现双逆变器的并网供电。提出一种新型主从控制方法，通过对主从机不同的SPWM调节速度的控制，实现电流内环电压外环控制。提出了系统软启动以及过流之后重启动的控制思想，保证系统始终处于安全工作状态，并且可以快速响应。通过UART完成两单片机之间通信，实现了从路输出相位跟随主路的目标。利用SPI的通信模式与采样模块相配合，加入系统的PID算法的分段调节，实现了高精度的采样和快速的系统闭环控制。本系统输出电压较为稳定，THD在2%以下，可以实现两逆变器输出电流按比例分配为1:1、1:2、2:1，效率达到90%以上。
This design adopts STM32 single-chip microcomputer as the main control chip, adopts bipolar SPWM modulation method, and uses single-phase full-bridge inverter circuit as the core circuit to realize grid-connected power supply of dual inverters. A new master-slave control method is pro-posed, which realizes the current inner loop voltage outer loop control by controlling the different SPWM adjustment speeds of the master and slave machines. The control idea of system soft start and restart after overcurrent is proposed to ensure that the system is always in a safe working state and can respond quickly. The communication between the two single-chip microcomputers is completed through UART, and the goal of the output phase of the slave circuit to follow the main circuit is realized. Using the SPI communication mode to cooperate with the sampling module, adding the segmented adjustment of the system’s PID algorithm, realizes high-precision sampling and fast system closed-loop control. The output voltage of this system is relatively stable, and the THD is below 2%, and the output current of the two inverters can be distributed proportionally to 1:1, 1:2, 2:1, and the efficiency reaches more than 90%.