基于增益连续扩张状态观测器的永磁同步电机电流解耦控制

Current Decoupling Control of PMSM Based on an Extended State Observer With Continuous Gains

为解决传统电流解耦控制方法在电感参数失配时解耦效果不佳的问题,提出一种基于增益连续扩张状态观测器(extended state observer,ESO)的电流解耦控制方法。该方法通过ESO获得了电阻压降、交叉耦合、以及其他确定和不确定因素所引起扰动的综合观测和补偿。扰动补偿控制不仅实现了励磁和转矩控制回路间的解耦,而且将各子系统控制对象简化为一阶积分环节,从而使得调节器无需积分项,简化了设计,克服积分饱和所带来的不利影响。与基于fal()函数的常规ESO不同,文中提出了一种具有连续可微特性的非线性函数,在优化fal()函数"大误差小增益,小误差大增益"特性的同时,克服其增益在切换点处的突变问题,且所提非线性函数具有统一表达式,避免切换点判断。论文对ESO参数选择、系统稳定性等进行了讨论。最后,通过实验进行验证。

To circumvent degradation of the decoupling performance with the conventional current decoupling schemes under parameter mismatch,an extended state observer(ESO)with continuous gains was proposed and based on the observer a new current decoupling control strategy was presented.By using the proposed ESO,the resistance voltage drop,the cross coupling related with the inductance,as well as the extra disturbances introduced by certainties and uncertainties,were estimated and compensated as a whole disturbance entity.By compensating all of the disturbances,not only the magnetizing and the torque control loops were decoupled,but also the plant in the individual subsystem was simplified to a first-order integrator.As a result,the integrating term,otherwise usually included in the conventional current regulator,is not necessary in the new control system,which facilitates design of the control loops,as well as allows the negative effects of integrating saturation removed.Different from the ESO based on the conventional fal()function,a novel continuously differentiable nonlinear function was found to form the new ESO.The desired characteristic of the fal()function,i.e.lower gain to bigger error and higher gain to smaller error,was improved,in addition to that jump of the gain at the switching point was avoided.Meanwhile,the proposed error correction function can be uniformly represented with a mathematical equation,avoiding switching action between two different mathematical equations.Design of the parameters involved in the ESO,as well as its stability were discussed in this paper.At last,some experimental results were reported to make validation.