Purpose

The power conversion system powers all of the vehicle’s low voltage systems from the HV pack. The team has historically used Vicor DCM modules (Vicor DCM3623TA5N17B4T70) for isolated LV power, however they offer relatively poor efficiency (75-85%) at our expected loads .

The Vicor module is a highly integrated device with no opportunity to improve it’s performance, so we have decided to investigate creating our own converter.

Requirements

• Isolated output

• > 60W continuous power output

• More efficient than the Vicor module

• 90-153VDC Input

• ~12V output

Goals

• 10W efficiency of > 90%

• 30W efficiency > 94%

Other Background

Our battery pack consists of 36-S LG M50T cells, so these are the electrical characteristics:

We want our PCS to have components spec’d for a nominal input voltage of 130.68 V

Topology

Idk these are a thing:

InnoSwitch4-CZ | Power Integrations

ClampZero | Power Integrations

ZVS is achieved by the above using an active clamp flyback. LLC is another popular ZVS topology, but it only operates at resonance at a fixed buck ratio which may hurt efficiency for us since the pack varies in voltage greatly.