摘要
针对无电压传感的三相PWM整流器虚拟磁链估计中存在直流偏置和初值等问题,本文提出一种具有自适应功能的新型虚拟磁链滑模观测与控制策略。该策略将滑模变结构控制引入虚拟磁链观测器中,以Sigmoid函数为切换函数估计出网侧电源电压值,根据理想磁链与虚拟电动势的正交关系设计了自适应控制率来动态调整磁链补偿基准,使其能够快速准确地跟踪网侧电压波动带来的磁链变化,实现实时检验和修正虚拟磁链值的作用。新型的虚拟磁链观测器合理减少了传感器的数量,同时提高了虚拟磁链的观测精度,将其应用于整流器DPC系统中,仿真和实验结果表明,新型无电压传感控制策略有效抑制了直流母线电压动态响应波动,更有利于滤除网侧电流谐波,改善电能质量。
In the three-phase VSR control system, in order to solve the errors caused by direct current drift and initial value in flux estimation under the traditional no voltage sensors control, a new adaptive sliding-mode observer with virtual flux orientation under non-line voltage sensors control is presented in direct power control(DPC) system. In the new observer, the power supply voltage value is estimated by the switching function based on Sigmoid function. Meanwhile, we design a novel adaptive controller to adjust the compensated reference flux based on virtual flux linkage to be perpendicular to grid voltage. This adaptive sliding-mode observer has improved the virtual flux estimation precision, according to the justified tendency of reduction of the number of the sensors. As an efficient solution to improve the power quality used in DPC system, the proposed control strategy has effectively inhibited the bus voltage fluctuation and harmonic interference. The good dynamic and static performance is verified by simulation and experiment.
出处
《电工技术学报》
EI
CSCD
北大核心
2015年第12期152-161,共10页
Transactions of China Electrotechnical Society
基金
国家科技支撑计划项目(2012BAF09B02)
关键词
PWM整流器
虚拟磁链
自适应滑模观测器
直接功率控制
无电压传感
PWM rectifiers,virtual flux,adaptive sliding-mode observer,direct power control(DPC),non-line voltage sensors control
