FPGA在三相PWM逆变器死区补偿中的应用

Application of FPGA to dead band compensation of three-phase PWM inverter

为避免三相PWM逆变器中上下桥臂开关管发生直通短路故障,设置了死区。但死区使逆变器输出的电压基波幅值减小、谐波增加、调制频率受限制,尤其使电机的低速运行性能变差,必须对其进行补偿。在电流反馈补偿的原理基础上,应用FPGA借助VHDL语言编写的设计软件,对死区进行补偿,得到了很好的效果。

In three-phase inverter, dead band is set to avoid direct through short circuit of switch diodes in upper and lower bridges. Anyhow, dead band reduces the output fundamental voltage amplitude, increases harmonic, limits modulation frequency, and even more worsens the motor's performance in low velocity. So the compensation is necessary. On the basis of current feedback compensation principle, the dead band is compensated by design software programmed by VHDL language in use of FPGA, with high efficiency.