电力机车单相PWM整流器μ综合直接电流控制

μ-synthesis Direct Current Control of Single-phase PWM Rectifier for Electric Locomotive

外界环境改变以及功率器件老化等因素,会不可避免地导致电力机车单相脉冲宽度调制(pulse width modulation,PWM)整流器系统网侧电路参数发生变化,这一现象易影响整流器系统控制性能。为提升单相PWM整流器系统在网侧电路参数摄动情况下的鲁棒性,提出一种基于结构奇异值(structure singular value,SSV)理论的μ综合直接电流控制(directcurrentcontrol,DCC)策略。在单相PWM整流器dq坐标数学模型的基础上,得出电流环系统状态空间;利用性能加权函数约束电流控制系统跟踪精度、规划抗干扰能力以及限制控制输出大小,同时引入虚拟性能不确定模块,进一步归纳出具有结构化不确定性的单相PWM整流器μ综合控制问题;经D-K迭代所得该μ综合问题结构奇异值曲线峰值为0.895,表明μ综合直接电流控制器可使单相PWM整流器系统满足鲁棒稳定与鲁棒性能要求;通过半实物仿真平台对μ综合DCC策略与直轴交轴(direct-axis quadrature-axis,DQ)电流解耦控制策略进行实验对比研究,结果表明:所提控制策略动态响应速度快,且在网侧等效电感参数摄动情况下系统鲁棒性较强。

The changes of grid-side circuit parameters caused by the external environment and aging of power devices easily affect the control performance of the single-phase PWM rectifier system for the electric locomotive.Aμ-synthesis direct current control strategy based on the structure singular value theory is proposed in this paper,which helps to improve the robustness of the single-phase PWM rectifier system under the grid-side circuit parameter perturbation.Based on the dq coordinate mathematical model of the single-phase PWM rectifier,the state space of the current loop system is obtained.The tracking accuracy,anti-interference ability and control output size of the current control system are constrained by the performance weighted function.Meanwhile,the virtual performance uncertainty module is introduced to further conclude theμ-synthesis control problems of the single-phase PWM rectifier with structural uncertainty.The peak value of the structure singular value curve obtained by D-K iteration is 0.895,which shows that theμ-synthesis direct current controller can make the single-phase PWM rectifier system meet the requirements of robust stability and robust performance.The hardware-in-loop system is adopted to verify the proposed algorithm via comparison with the direct-axis quadrature-axis current decoupling control strategy.The experimental results show that the proposedμ-synthesis DCC algorithm has superior dynamic performance and strong robustness when the equivalent inductance parameter perturbation occurs.