Ask where an EV's range comes from and most people point at the battery. But a meaningful share of range is won or lost in the inverter — the box that turns the battery's DC into the AC the motor actually uses. Every conversion has losses, and those losses are heat that came out of your range. Improve the inverter and you extend range without adding a single cell. A 2023 GM grant is about exactly that lever.
The record: on June 27, 2023, GM Global Technology Operations LLC was granted US11689093B2, a “Current source inverter having hybrid switches.” The CPC classes are power-electronics classes — H02M 7/5387 and 7/5388 (DC-to-AC conversion), H02M 1/0087 (loss reduction), plus propulsion class B60L 50/60. The interesting phrase is “hybrid switches”: mixing switch technologies in one inverter.
Here is the mechanism. An inverter switches on and off thousands of times a second to synthesize AC. Each switch type — silicon IGBTs, silicon-carbide MOSFETs, others — has its own trade-offs in switching speed, conduction loss, and cost. A “hybrid” inverter combines types, using each where it performs best, to minimize total losses across the operating range. It is a way to get more of the expensive switch's efficiency without paying for it everywhere.
Why does this matter for the spec sheet? Because inverter losses show up as reduced range and as heat that has to be cooled — a double cost. A few percentage points of conversion efficiency, sustained across a drive, is real range and less thermal load. The chemistry sets how much energy you store; the power electronics decide how much of it reaches the wheels. The inverter is where stored energy becomes motion, minus a tax, and this patent is about cutting the tax.
The honest framing of “hybrid”: it is an engineering optimization, not a breakthrough chemistry or a new physics. Mixing switch types is a cost-versus-efficiency balancing act — you accept more design complexity to avoid using the priciest switch everywhere. GM patenting a specific hybrid-switch current-source inverter is a claim on one such optimization, in a part of the car that rarely gets attention but quietly governs efficiency.
The caveat: a granted inverter topology is a method, not a measured range figure, and the gains depend on the operating profile. But the broader point holds. On paper versus on the road, EV efficiency is decided in unglamorous boxes like the inverter as much as in the battery. Follow the kilowatt-hours and you find the inverter taking its cut — and a 2023 GM grant is about shrinking it.