48 V is emerging as a safe-to-touch alternative voltage level for electric vehicles (EVs). Using low- instead of high-voltage drive train reduces isolation efforts, eliminates the risk shock, and thus increases system safety. In contrast, fast charging battery would require very high currents incompatible with widely established vehicle infrastructure. Instead employing additional on board powe...

Recall the global U(1) symmetry: Ψ→ e−ieΨ i.e. δΨ = −ieΨ. Let’s run the Noether argument: consider a slightly deformed, infinitesimal version of the symmetry transformation: Ψ→ Ψ + ρδΨ, where is just a small number to keep track of order, and ρ is some general function of x. The fact that we have a U(1) symmetry tells us the action must change under the deformed transformation by δS = ∫ dx J N∂...