永磁同步发电系统中转矩和磁链精确线性化解耦控制

为了实现直接转矩控制(direct torque control,DTC)永磁同步发电系统直流输出电压的快速而平稳控制,需要电磁转矩与定子磁链控制之间的解耦。该文首先根据定子静止坐标系中定子电流和定子磁链状态方程,推导出以电磁转矩和定子磁链幅值平方为状态变量的永磁同步发电机仿射非线性模型。然后以该非线性模型为基础,结合输入输出线性化理论推导出以电磁转矩和定子磁链幅值平方为输出变量的定子电压矢量给定数学模型。根据定子磁链幅值平方和电磁转矩跟踪控制要求,设计出线性化后系统输入控制变量形式,并据此进一步计算出定子电压参考矢量。最后利用空间电压矢量调制(space voltage vector modulation,SVVM),实现永磁同步发电机定子磁链幅值和电磁转矩控制的动态解耦。实验结果表明,采用该文提出的新型控制策略发电系统具有理想的电磁转矩和定子磁链幅值跟踪性能,转矩及电流脉动较小,直流输出电压控制迅速而平稳。

Precision Linearization Decoupling Control for Torque and Flux Linkage of Permanent Synchronous Generating System

Decoupling between torque and stator flux linkage is necessary to achieve the quick and smooth control for output DC voltage of permanent synchronous generating system based on direct torque control(DTC).Firstly,a nonlinear mathematical model with state variables of torque and square of stator flux linkage amplitude was deduced according to the state equations of stator current and flux linkage in static coordinate frame in this paper.Secondly,the stator voltage mathematical model was constructed with the output variables of torque and square of stator flux linkage amplitude by the input-output linearization method according to the deduced nonlinear model.Thirdly,the input control variables of linearized system was designed on the track control demands for toque and stator flux linkage,and on which the given stator voltage vector was calculated.At last,the space voltage vector modulation(SVVM) was applied to obtain the dynamic decoupling control between the torque and stator flux linkage.The experimental results show that the generating system with the proposed control strategy has the ideal tracking performance of torque and stator flux linkage with small ripples of torque and current,and the output DC voltage is modulated quickly and smoothly.