基于AVR单片机的数字正弦逆变电源设计

Design of digital sine inverter power based on AVR singlechip

提出一种高性能的直流-交流(DC-AC)数字式正弦逆变电源的设计方法。采用SG3525A与AVR系列单片机AT90PWM2作为控制器进行设计。SG3525A产生PWM波进行前端的推挽升压控制,通过直流母线上高电压的负反馈,使得全桥逆变的输入电压保持稳定。AT90PWM2的波形发生器产生SPWM波形对后级全桥逆变进行控制,通过采样全桥逆变后的输出电流以及输出电容电压,实现双闭环控制,使得逆变电源在各种不同类型负载条件下都能具备良好的输出特性以及负责效应。实验结果表明:1 kW样机性能稳定,逆变效率大于90%,在不同种类的满功率的负载条件下均能保持电压精度为220 V±1%,频率精度50 Hz±0.1%,THD小于1%。

This paper proposed a design approach which dealt with high-performance DC-AC （DC-AC） digital inverter problem. In this method, SG3525A and AVR mieroeontroller AT90PWM2 were used as control core for design. The PWM wave was generated by SG3525A and could control the push-pull boost control. The full-bridge inverter＇s input voltage kept stale through the negative feedback of the high voltage DC bus. The SPWM wave was generated by AT90PWM2 waveform generator and could control the full-bridge inverter. Double-loop control was achieved by sampling output inductive current and output capacitor voltage. So that the inverter power had a good performance and responsible effect under all kinds of load conditions. Finally, the following results can be obtained： 1kW prototype performance is stable, inverter efficiency is more than 90%, under different types of full-power load conditions, the voltage accuracy is 220V±1%, the frequency aeeuraey is 50Hz 0.1% and THD is less than 1%.