基于等价输入干扰的UPS逆变器H_(∞)重复控制

Equivalent input disturbance-based H_(∞)repetition control of UPS inverter

针对不间断电源(uninterruptible power supplies,UPS)逆变器H_(∞)重复控制系统在跟踪精度和扰动抑制性能之间的固有约束,提出一种附加等价输入干扰(equivalent input disturbance,EID)补偿的H_(∞)重复控制策略,实现对负载突变等干扰的快速抑制和参考电压的高精度跟踪。首先采用状态空间平均法建立UPS逆变器的动态数学模型,并给出总体控制框图;在H重复控制器的基础上,求得一组负载突变时仍能保持稳定的状态反馈增益;其次,通过状态观测器构造EID估计器,给出了具体设计步骤。实验结果表明,所提控制策略能将UPS逆变器遭受非线性强干扰后的恢复时间缩短约1个周期,输出电压有效值的最大偏移量降至0.09%,改善UPS逆变器重复控制系统对扰动抑制的动态性能。

Aiming at the inherent constraints between tracking accuracy and disturbance suppression performance of H_(∞)repetitive control system for uninterruptible power supplies(UPS)inverter,an H_(∞)repetitive control strategy with equivalent input disturbance(EID)compensation is proposed,which realizes the rapid suppression of load sudden change and other disturbances and the high-precision tracking of reference voltage.Firstly,the dynamic mathematical model of UPS inverter is established by using the state space average method,and the overall control block diagram is given.Based on the H_(∞)repetitive controller,a set of state feedback gains that can maintain stability when the load changes suddenly are obtained.Secondly,the EID estimator is constructed by a state observer,and the specific design steps are given.The experimental results show that the proposed control strategy can shorten the recovery time of UPS inverter after suffering from strong nonlinear interference by about one cycle,reduce the maximum offset of output voltage RMS to 0.09%,and improve the dynamic performance of UPS inverter repetitive control system for disturbance suppression.