逆变器电压电流双闭环控制系统设计

Design of voltage and current double closed-loop control system for inverter

逆变器在可再生能源发电中作为连接能量输入与输出负载的装置,发挥着重要作用,采用合适的控制系统可以得到满足后端电能质量需求的电能。针对电压单环控制调整滞后的缺点,补充中间电流反馈环节以提高控制系统的工作频率。比较了电感电流内环与电容电流内环反馈系统的区别,选取负载抗扰动性能更强的电容电流反馈系统,该控制方案对一般及整流性负载的干扰同时具有较强的平抑能力。针对输出电压及电感电流在数学模型上的交叉耦合作用,通过耦合信号前馈削弱其对控制系统的影响。提出一种基于"模最佳"的整定方法,对调节器的参数进行设计,最终利用仿真验证了所提设计方案的有效性。

The inverter is able to output the power which can meet the load requirements with appropriate control systems, and plays an important role in renewable energy generation systems as a device connecting renewable energy generation and load. In consideration of the regulation lag of single voltage loop, an inner current loop was added to improve the working frequency of the control system. The difference between the inductor current feedback and the capacitor current feedback was compared. The capacitor current feedback control system which suppressed the disturbance of general and rectifier loads more strongly was adopted. Regarding of the cross coupling of the output voltage and inductor current on the mathematical model, the coupling signal feedforwards were introduced to weaken their influence on control system. A design method was proposed to set the parameters of the control system based on theory of optimal module. Finally, an emulation model was developed and simulation results verified the effectiveness of the proposed method.