摘要
该文提出一种基于快速选择表的永磁同步电机改进模型预测转矩控制策略,以扩大输出电压矢量选择范围,同时减小双矢量模型预测转矩控制中忽略的定子磁链波动。在该方法中,通过增加有效电压矢量,使输出电压矢量方向和幅值均可调节,并采用快速选择表来降低算法复杂度,在确保转矩性能的同时,对磁链波动进行综合考虑。首先,对电压矢量与转矩和定子磁链之间的关系进行综合分析,并根据定子磁链值进行扇区判断;其次,依据实际转矩与给定转矩之间的差值和扇区值在快速选择表中进行有效电压矢量选择,以降低对有效电压矢量的选择时间;最后,根据无差拍控制原理计算出各个电压矢量作用时间。仿真和实验结果表明,该方法可以减小转矩脉动和磁链波动,并能有效降低算法复杂度。
An oulput volage vector with adjustable amplitude has been synthesized with the selected.voltage vector of ffectiveness and a zero by calculating the duty cycle in the two-vector model prediction torque control,eftivctly reducing the actual and design value eror.Due to the limited sleletion range,there are still some defeets.Thus,some three-vector improvement measures have been proposed with different seleetion methods.Based on the new two-vector model prediction torque control,a torque control strategy for three-vector model prediction is proposed based on the fast selection table.A synthetie voltage vector with adjustable amplitude and range is obtained by increasing the effctive voltage vector,and a fast selection table is proposed 1to reduce the computalion of the efetive voltage vector selection.Firstly,by analyzing the inluence of the voltage vectors on the slope of torque and stator flux,it can be known that the zero-volage vector mainly afects the torque ripples,and the infuence on the stalor fIux is almost negligible.Therefore,the slope of stator flux under zero voltage vector can be neglected in the operation time allocation.Secondly,the fast sclection table is constructed according to the effect of the efective voltage vector on torque and stator flux.Thus,the prediction times can be greatly reduced while selecting the efective voltage vector.Then,the sector judgment is made according to the position of stator Dux at the current time,and the efective voltage vector is slected quickly according to the error of actual and designed torque values and the value of sectors in the fast selection table.Finally,the operating time of voltage vectors is calculated by the prineiple of deadbeat control.The simulation test mainly verifies the transient experiment.Firstly,the motor speed is set at 1500 r/min and started in a no-load state.Then,when the motor runs stably to 1500 r/min,the simulation test condition of load torque is suddenly added to 3Nm at 0.18.Simulation waveform shows that this strategy can efctively reduce flux fluctuation and torque ripples on the virtual platform and reduce the current harmonics from 13.27%1to 6.77%。In order 1to further verily the fesibilily of the algorithm,a relevant experimental plaform is buil,which is mainly divided into two parts:steady-state experiment and transient experiment verification.The steady-state experiment mainly verifes the motor operation condition under low speed without load and high speed with load.The torque ripples and flux fluctuation can be effectively improved to a certain extent under both conditions,and the current harmonics under high speed with load are reduced from 32.37%to 25.68%。The.transient experiment is to add Load to the motor under stable operation suddenly.Both experiments show that the.control strategy in this paper can reduce current harmonics,and the steady-state performance is better than before.In addition,whem the torque changes,although the speed will be afected to some extent,the results will be less afected,and the dynamie response can be maintained quickly.
作者
兰志勇
罗杰
李延昊
李超
李福
Lan Zhiyong;Luo Jie;Li Yanhao;Li Chao;Li Fu(School of Automation and Electronic Information Xiangtan University,Xiangtan 411105 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2023年第21期5749-5757,共9页
Transactions of China Electrotechnical Society
关键词
永磁同步电机
模型预测转矩控制
三矢量
无差拍控制
开关表
Permanent magnet synchronous motor
model-predicted torque control
three vectors
deadbeat control
switching table
