单相级联H桥整流电路非线性控制策略

针对电力电子牵引变压器输入级单相级联H桥(CHB)整流电路的非线性及扰动工况,提出一种基于静止坐标系的非线性优化控制策略。根据系统仿射非线性模型及微分几何理论,提出基于部分反馈线性化的零动态设计方案,对其线性部分采用二次型最优方法以确定反馈增益,并引入谐振环节以实现零相差跟踪;对于零动态则采用基于扩张状态观测器的自抗扰控制策略,以提高系统在负载大范围扰动时的控制品质。实验结果表明,该控制策略能提高CHB系统在电网电压及负载扰动时的动态响应速度,保证网侧电流及直流电压快速稳定调节,同时使网侧在单位功率因数下运行,各模块直流电压均衡。

Nonlinear Control Strategy of Single-Phase Cascade H-Bridge Rectifier

A static coordinate based nonlinear optimal control strategy was presented for the single-phase cascade H-bridge(CHB)rectifier,serving as the input stage of the power electronic traction transformer,for its nonlinear and disturbed operating conditions.According to the nonlinear affine model of CHB and nonlinear differential geometric theory,the zero-dynamic control scheme based on partial feedback linearization was preferred.For the linear part,the feedback gain was optimized using the linear quadratic control method,and a resonant controller was added for achieving zero phase error tracking.For the zero-dynamic variable,the active disturbance rejection controller(ADRC)based on extended state observer was designed to improve its dynamic response under wide range of load disturbance.Experimental results show that the proposed control strategy has good performance in improving dynamic response under grid voltage and load disturbances,guaranteeing fast regulation and stability of grid current and dc voltage,meanwhile achieving unity power factor operation and dc voltage balance of each module.