一种基于FPGA的新型移相PWM发生器

Design of a new phase-shift PWM generator based on FPGA

在逆变开关电源中,隔离变压器通常要求正、反方向的磁通变化量相等,以防止偏磁等现象发生,在移相全桥DC-DC开关电源中尤为重要。介绍了一种基于FPGA的移相PWM(pulse width modulation)发生器,该发生器主要包括分频模块、计数模块、比较模块和死区控制模块等;该发生器不仅将移相PWM数字化,且考虑了逆变全桥DC-DC开关电源中隔离变压器的工作特点。仿真结果表明,该发生器实现了移相PWM输出,可以满足逆变电源的工作要求。

In inverter switch power,the magnetic change in positive and negative in insulating transformer is needed equal,which prevent magnetic flow,specially in phase shift full bridge DC-DC switch power. A phase shift PWM pulse width modulation generator based on FPGA is introduced in this paper,which consists of dividing frequency module,counter module,composition module,and dead area control module,ere.The design of the generator not only make phase shift PWM with digitization,but also consider the working characteristics of insulating transformer in inverter full bridge DC-DC switch power.The simulation results show that realize the output of phase shift PWM ,and meet the working requirements of inverter power source.