高频伺服系统逆变器死区非线性补偿策略  

Dead-Time Nonlinearity Compensation Strategy for Inverter in High Frequency Servo Systems

作　　者：周国祥 王邦继[1] 王梦轩 许琨辉 Zhou Guoxiang;Wang Bangji;Wang Mengxuan;Xu Kunhui(School of Physical Science and Technology Southwest Jiaotong University,Chengdu 610031 China)

机构地区：[1]西南交通大学物理科学与技术学院,成都610031

出　　处：《电工技术学报》2025年第8期2630-2642,共13页Transactions of China Electrotechnical Society

摘　　要：针对伺服系统在高开关频率应用下逆变器死区非线性效应引起的电流谐波畸变问题,提出无死区双调制波脉冲宽度调制(PWM)和逆变器非线性补偿相结合的策略。首先基于反并联二极管的续流特性,在互补驱动脉冲之间加入驱动空缺区以避免死区时间的引入。其次通过向直轴注入斜坡电流来获取逆变器非线性特性所对应的误差电压,采用线性迭代插值法来求解逆变器非线性误差电压与电流幅值之间的关系,最终实现逆变器非线性误差电压的在线补偿。同时阐述了引入死区时间后再进行补偿和无死区双调制波PWM的区别,对两者解除占空比限制的效果进行了分析。最后通过仿真和实验表明,所提策略能够增加输出电压的线性调制区,消除由死区时间导致的输出占空比限制,有效地抑制了高开关频率逆变器死区非线性效应导致的电流谐波畸变。此外所提策略易于实现,无需额外的控制环路计算,可适用于更高开关频率的伺服驱动控制系统。In servo systems,the bandwidth of the current loop is increased by raising the switching frequency.However,the dead-time nonlinearity of the voltage source inverter(VSI)intensifies with the increase of switching frequency,causing the deviation between the actual and the theoretical output voltage,resulting in serious distortion of the inverter output current waveform.The requirement of computational power constrains the implementation of high switching frequency control.Consequently,the dead-time nonlinearity compensation strategy should be more straightforward to decrease computational time,especially for high switching frequency applications.The amplitude increase is relatively modest at a low switching frequency but significantly surges at a high one,bringing on a severe degradation of the linear modulation region.It is an imperfect solution to compensate after the occurrence of dead-time,which unavoidably introduces compensation errors.Furthermore,the accurate solution of inverter nonlinear voltage error(INVE)under different currents represents a crucial aspect of achieving exact INVE compensation.Nevertheless,the existing methods are complex.This paper proposes a novel strategy that combines no-dead-time double modulation wave pulse-width modulation(PWM)and inverter nonlinearity compensation for analyzing the dead-time nonlinearity and the nonideal characteristics of the inverter on the output voltage error.Firstly,according to the continuous current characteristics of the anti-parallel diode,the drive vacancy area is added between the complementary drive pulses to avoid the introduction of dead time.Compared with the ideal space vector pulse width modulation(SVPWM),an auxiliary modulating wave is added.Depending on the current polarity,its amplitude is adjusted up or down from the original modulating waveform.The underlap periods are generated between the complementary drive pulse by contrasting the double-modulating and the triangular carrier waves.It is practical to avoid both the bridge arm shoot-through

关 键 词：永磁同步电机 逆变器死区非线性 死区消除 非线性补偿 误差电压计算 

分 类 号：TM464[电气工程—电器]