新型逆变器滑模控制方案研究

Analysis and Design of Sliding Mode Control for Novel Buck Inverter

针对一种由两组独立对称的双向Buck变换器组合的新型DC/AC逆变器拓扑提出了滑模控制策略,实现信号的功率放大。给出了新型逆变电路的工作原理,对滑模控制进行了深入分析,并运用反函数变换替换参考源,在新建的相平面内改进了时不变的滑模面控制方程和控制规则。运用等效控制理论分析了滑模控制的存在和稳定条件,给出了滑模区域及动态设计和滞环控制设计依据。并且讨论了负载属性的影响以及寄生电阻对输出电压的影响。根据分析结果设计了滑模控制系数及系统参数。滑模控制方案使得滑模运动具有零阶动态特性,能有效克服系统参变量变化和外部扰动,充分发挥了快速响应和鲁棒性强的优点。实验结果证明了分析设计的正确性。

Sliding mode control strategy for novel DC/AC Buck inverter is proposed in this paper, it is composed of two independent symmetrical bi-directional Buck converters to be used in AC signal power amplifier design. The sliding mode control is applied to track and amplify DC-biased sinusoidal signal for the framework of the inverter. A time-independent sliding mode surface and corresponding sliding control law are obtained in selected phase plane, which is derived by the application of inverse function theorem. The existence and stability of the sliding mode control are analyzed by applying equivalent control, and the surface is modified for ensuring sliding domain. System parameters and converter losses are discussed. The sliding mode control scheme has zero order dynamics and robustness with respect to both external disturbances and variations on the load and input voltage. Experimental results are included to validate the analysis.