Servo Driver Inverter Circuit Based on Pure Resistance Current Sampling

The current sampling method is the key to determine the performance of the servo driver, and widening the current loop bandwidth is one of the main ways to improve the dynamic performance of the driver. This paper proposes a scheme based on purely resistive sampling of the output phase current of the servo driver. That is, the two-phase current of PMSM is sampled by pure resistance, and the phase current analog signal is analog-digital converted by TI's AMC1204. The phase current is analog filtering and digital filtering to improve the sampling effect of the phase current. Finally, the experimental results show that the designed servo driver current loop bandwidth frequency reaches 1.8kHz, which is much higher than the Hall current sensor scheme (current loop bandwidth frequency is 1.2kHz), which greatly improves the dynamic performance of the servo system.