Multilayer PCB Bus Layout for Faster Power Inverter Switching
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Solution Overview
Problem
Power inverter designs face challenges with voltage overshoots due to the collapse of magnetic fields during switching, which limits switching speed and increases switching losses.
Innovation Solution
The use of electromagnetically coupled high-side and low-side electrical conductors in a multilayer printed circuit board design, where the conductors are partially overlapping or interleaved, reduces the need for energy dissipation and minimizes voltage overshoot by maintaining a constant magnetic field, allowing for faster switching speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If low inductance design is employed to reduce voltage overshoot, then switching speed is improved, but switching loss increases
Solution Approach 1:
The patent combines the high-side and low-side input lines into a single shared input line, eliminating the need for separate conductors. This merging reduces the overall loop inductance while maintaining electromagnetic coupling between the high-side and low-side switches, thereby reducing voltage overshoot and enabling faster switching without proportionally increasing switching losses
Solution Approach 2:
The shared input line acts as an intermediary element that provides electromagnetic coupling between the high-side and low-side switches. The inductance of this shared line serves as a mediator that limits voltage overshoot during switching transitions, allowing faster switching speeds while controlling the magnitude of voltage spikes and associated losses
2Loss of energy
If low inductance design is used to allow faster switching, then switching loss is reduced, but voltage overshoot increases
Solution Approach 1:
By merging the high-side and low-side input lines into a shared conductor, the patent creates a unified current path that provides inherent electromagnetic coupling. This combination reduces the overall loop area and inductance, minimizing voltage overshoot during switching while maintaining low switching losses
Solution Approach 2:
The shared input line serves as an intermediary that provides controlled inductance to limit voltage overshoot. The inductance of this shared line acts as a natural snubber, slowing the rate of current change during switching transitions and thereby reducing voltage spikes without significantly increasing switching losses
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces voltage overshoot and enables faster switching times without compromising switching speed, thereby improving the performance and efficiency of power inverters.
Implementation Method 1
Over voltage can also be mitigated by creating mutual electromagnetic coupling between the high-side (e.g., positive side) and the low-side (e.g., negative side) electrical conductors, where the electromagnetic field created by the current through the high-side (e.g., positive side) conductor envelops the low-side (e.g., negative side) electrical conductor
Implementation Method 2
When the high-side electrical conductor and low-side electrical conductor are electromagnetically coupled as current flows in the side that is ON, either the high-side or the low-side, a magnetic field is generated on the side that is OFF. In this situation, when it is time to change the side that is ON, via switching (i.e., high-side to low-side or vice versa), because there is mutual inductance, the resulting mutual field does not need to change.
Data Source
AI summary
An article for a power inverter, includes a multilayer printed circuit board having a first and second electrically conductive wiring layer and at least a first dielectric layer interposed between the first and second electrically conductive wiring layers. Each conductive wiring layer includes a common input and output line, the common input and output lines at least partially overlapping one another in a projection along a thickness of the multilayer printed circuit board. A set of input mounting pads is carried by the first common input line and a set of input mounting pads is carried by the second common input line, the input mounting pads of the second set of input mounting pads are interleaved with the input mounting pads of the first set of input mounting pads along a first axis. The article further includes a set output mounting pads carried by the common output line.