在现代雷达控制系统中,伺服系统的转速稳定性和定点精度,直接影响到最终成像品质。文中针对伺服系统常用的永磁同步电机控制器中的功率器件金属-氧化物半导体场效应晶体管(MOSFET)展开研究,主要分析了MOSFET 的米勒效应,介绍了MOSFET 的电路模型和开通过程,分析了米勒平台电压的振荡原因和米勒效应对驱动电路的危害,并设计两种优化电路来抑制米勒效应。理论分析和实验结果表明,经过改进的驱动电路有效抑制了米勒效应产生的栅源脉冲电压尖峰。所设计电路已应用于20 kHz/1 kW 永磁同步电机驱动器,有效提升了雷达伺服系统的环境适应性和稳定性。

In modern radar control system, the speed stability and fixed point accuracy of servo system directly affect the final image quality. This article focuses on the research of the power device metal-oxide-semiconductor filed-effect transistor (MOSFET) in permanent magnet synchronous electric control system. The problem of MOSFET Miller effect is analyzed, and the circuit model and turn-on process of MOSFET are introduced. The causes of voltage oscillation of Miller effect on the drive circuit are analyzed. Tow optimization circuits are designed to suppress the amplitude of the gate-source pulse voltage generated by the Miller effect. Theoretical analysis and experimental results show that the improved drive circuit has limited suppression of gate source pulse voltage spikes caused by Mille effect. The improved circuit has been applied to 20 kHz/1 kW motor controller, effectively improves the stability of radar servo system and environmental adaptability.

TB937