Distributed power supply has infinite scope preferentially ideal for automotive powertrain components of hybrid electric-vehicle (HEV), electric-vehicle (EV) and the plug-in hybrid electric-vehicles (PHEVs). Usually, automotive powertrains use centralized power supply via a multichannel transformers that takes 12-V dc power from battery and converts it to supply 6 isolated gate-drive circuits. Many a time, designers might face numerous challenges with respect to the centralized transformer models. The issues might range from electromagnetic interference (EMI) to layout complexities, larger board space, as well as costs of higher printed-circuit-board (PCB). The reason being, multiple layers are required to route isolated power/signal lines.
Creating a distributed power supply is a simple task which requires a few discrete components along with a mini high-efficiency transformer that needs to be placed juxtaposed to IC that integrates integrated flyback controller with automotive-grade smart gate drive. This leads to significant decrement in average footprint, EMI, and noise coupling between IGBT (Insulated-Gate Bipolar Transistor) channels.
Simplification Of Design
The distributed power supply framework gives better flexibility to the designers in terms of planning circuit layouts. The low-voltage plane can be easily identified and isolated from the high-voltage place. Also, it gets easier to manage and look after overall PCB routing. If you can see the below given figures, you will know the difference between IGBT gate-driver board based on distributed power supply and centralized power supply. You can easily make out that PCB layout is more simplified with way more efficient routing. You will find no PCB traces or intercrossing between high and low voltage circuits, increasing the signal integrity and keeping away unwanted noise disturbance in the signal lines.
The transformer used in the distributed power supply is 14 times smaller than the centralized transformer in terms of volume. In the below given figure you can see a single transformer placed right next to the centralized transformer. You can easily figure out the difference in dimensions of the two. Also, a sole low-profile transformer for every driver improves the robustness and reliability of complete system. It is much more efficient than the regular heavier, high-level transformers that are more susceptible to mechanical vibrations. Centralized power supply frameworks employ larger power-supply capacitors that come in a CAN package along with a high profile, designers usually prefer to install SMD package capacitors that are much smaller and equally efficient. The voltage requirements of the smaller ones is 10-20V less than the range demanded by centralized power-supply circuits.
Apart from simple design and robustness, the distributed power supply framework also helps in reducing the costs by minimizing the overall size of boards and PCB layers. The distributed framework of drivers along with a single transformer permits all components to be stay close and save significant board space. It also brings down total number of PCB layers as there is nil overlapping of low-voltage traces in the high-voltage planes.
Improved EMI Performance
The larger transformers in the centralized power system yield high EMI noise than a single mini transformer. In a distributed power supply system, every smart gate-drive optocoupler receives its own transformer along with integrated dc-dc controller for transferring power to the secondary end for the IGBT arm. So, to conclude, there can be no second opinion to the fact that distributed power supply framework simplifies designs of automotive multichannel IGBT gate-drive as brings up its overall efficiency, EMI performance, and several other aspects.
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