Universal Digital Class D Current Driver for Inductive Motors

Abstract

This thesis discusses the basic architecture, design details, circuit implementation, and measurements of a digital class D current driver.
The driver contains two main parts: a digital control loop and analog circuits.
Parts of the important part in the digital control loop contain noise shaper, plant compensator, and cable capacitance compensator. The noise shaper has two core functions: 1. It seeks to minimize the difference between the process variable and the set point. 2. It shapes the noise that is generated in the forward loop. The plant compensator is used to compensate for the output filter, the load, and the cable. The cable capacitance compensation is a measure-based technique to generate a negative output capacitance to compensate for the cable capacitance. The analog circuits consist of a full bridge, data acquisition circuits, and floating supplies.
Multiple simulation models have been made in Matlab. According to the simulation results, the amplifier shows its flexibility and performance to handle a large range of inductive loads.
A prototype has been implemented. The measurement results show that most of the hardware performance is as intended. Due to the time limitation, the whole amplifier is not tested.