Design and Torque Ripple Analysis of Brush-less DC Motor According to Delta Winding Connection

Abstract

In this study, we describe the design method of a Brush-less DC (BLDC) motor with delta winding connection. After designing delta winding connection model with the 60° flat-top region of the Back Electro-Motive Force (BEMF), an ideal current source analysis and a voltage source analysis, with a 6-step control, were conducted primarily employing Finite Element Method. In addition, as a current controller, we considered the Current Regulator with PI controller using Simulink for the comparison of torque characteristics. When the input current is controlled, the switching regions and reference signals are determined by means of the phase BEMF zero-crossing point. In reality, the input current variation depends on the inductance as well as input voltage, and it causes a torque ripple after all. Therefore, each control method considered in this research showed different torque ripple results. Based on the comparison, the causes of the torque ripple have been verified in detail.

Improving Speed Characteristics of High Torque Density Motors for Physical Human-Robot Interaction using Independent 3-Phase Winding Structure

“…With this system, since all three phases are excited by a single voltage source. The uneven distribution of voltage applied to each phase, as seen in Figure 2 (b), creates ripples in the operation of the BLDC motor [18]. 𝑉 𝑙𝑖𝑛𝑒 = 𝑉 𝑝ℎ𝑎𝑠𝑒 , 𝐼 𝑙𝑖𝑛𝑒 = √3𝐼 𝑝ℎ𝑎𝑠𝑒 ( 11)…”

Improving Speed Characteristics of High-Torque-Density Motors for Physical Human–Robot Interaction Using an Independent Three-Phase Winding Structure

“…With this system, all three phases are excited by a single voltage source. The uneven distribution of voltage applied to each phase, as seen in Figure 3b, creates ripples in the operation of the BLDC motor [17].…”