Analyzing the Influence of DC-Link Inductor Design on Adjustable Speed Drive Performance

DC-link filter in Adjustable Speed Drives (ASDs) with a diode bridge rectifier typically includes a DC-link capacitor and an inductor, which can be positioned either on the AC side or within the DC-link itself. In industrial drives, the inductor is more commonly placed in the DC-link due to its lower voltage drop compared to an AC-side configuration. The shape of the laminations in the core of a DC-link inductor (also known as DC-coil) is a crucial design element, as it significantly affects the magnetic properties, efficiency, and overall performance of the inductor. Selecting the appropriate lamination shape is essential for optimizing the magnetic flux path, minimizing losses, and fitting the physical constraints of the inductor. This work analyzes the commonly used EI core shape, highlighting its challenges, and demonstrates how the UI core shape can address these issues effectively.