摘要
不连续PWM调制与传统空间矢量调制相比能够降低开关次数与损耗,提高变换效率。然而,死区效应、管压降会引起感应电机的相电压非线性误差,导致定子电流谐波畸变增加,转子磁链观测精度降低,且传统的基于占空比的补偿方法并不适用于不连续PWM调制。针对不连续最小值调制策略(DPWMMIN)的损耗与电压误差展开研究,首先对导通损耗与开关损耗进行分析与计算,然后在考虑开关时间、死区时间、管压降的情况下对不同扇区三相桥臂电压误差进行推导。在此基础上,提出一种针对DPWMMIN调制方式的平均电压前馈补偿策略。最后通过仿真实验进行验证,结果表明该补偿策略能够有效降低定子电流的谐波畸变,增加转子磁链与速度观测器的精度,证明理论分析与补偿策略的可行性与正确性。
Compared with traditional space vector modulation,discontinuous PWM modulation can reduce switching times and losses and improve conversion efficiency.However,the dead-time effect and tube volage drop can cause phase voltage errors in the induction motor,increase harmonic distortion of stator current,reduce accuracy of rotor flux observer,and the traditional voltage error compensation method based on duty cycle is not suitable for discontinuous PWM modulation.In this paper,the loss and voltage error of DPWMMIN are studied.First,the conduction loss and switching loss are analyzed and calculated,and then the three phase-voltage of different sectors is deduced taking into account switching delay,dead time and tube voltage drop.The voltage error is deduced.From this an average voltage feedforward compensation strategy for DPWMMIN modulation is proposed.Finally,the simulation and experimental results show that the compensation strategy can effectively reduce the torque ripple and harmonic distortion of stator current and voltage,and increase the accuracy of the rotor flux observer.This proves the feasibility and correctness of the theoretical analysis and compensation strategy.
作者
汤梦阳
苗轶如
雍涛
TANG Mengyang;MIAO Yiru;YONG Tao(Key Laboratory of Smart Grid and Intelligent Control in Nanchong,Southwest Petroleum University,Nanchong 637001,China;College of Electrical and Information Engineering,Hunan University,Changsha 410082,China)
出处
《电力系统保护与控制》
CSCD
北大核心
2022年第2期21-29,共9页
Power System Protection and Control
基金
国家自然科学基金项目资助(51507055)
西南石油大学市校合作战略项目资助(18SXHZ0043)。
