在传统电压模式基础上,对单相全桥逆变器提出了一种前馈型电压模式控制方案,利用开关变换器稳态输入/输出占空比关系构造控制方程,引入输入电压前馈使得输入电压波动对输出无影响,同时在无积分反馈环节下输出电压就能稳定跟踪参考信号.避免了PID控制中积分项对系统性能的影响,控制实现上则采用输入电压积分电路求解控制方程中的开关占空比。进行了性能分析并与传统PID控制逆变器的模型比较。理论分析表明前馈型电压模式控制逆变器具有稳态跟踪性能好、抗输入电压扰动以及对负载跳变动态响应好的优点。仿真对比和实验验证的结果表明理论分析的正确性和前馈型电压模式控制的有效性。所提控制方案具有控制简单、模拟电路容易实现的优点.便于实际应用。
Based on the traditional voltage mode,a feedS-forward voltage mode control scheme is proposed for the single-phase full-bridge inverter. The control equation is created according to the steady-state input-to-output duty cycle of switching converter and the feed-forward of input voltage is adopted to suppress its impact on output voltage. Without integral compensation,the output voltage can track the reference signal stably to avoid the impact of the integral term of PID control on system performance. Integral circuit of input voltage is implemented to solve the duty cycle of control equation. The system performance is analyzed and compared with the model of traditional PID-controlled inverter. Theoretical analysis shows that the feed-forward voltage-mode-controlled inverter has better static tracking performance and faster response to load step change,and is immune to input voltage disturbance. The simulative and experimental results verify the correctness of theoretical analysis and the validity of the proposed control scheme. The control scheme is simple and practical ,which is easily realized with analog circuit.