in canada, all governmental power belongs to the federal government. provinces only have authority when it is granted to them by the federal government. there is no such thing as the feds encroaching on "state powers" because provinces are not states.
Plus the us constitution grants congress the power to “fix the Standard of Weights and Measures” in article 1, section 8. The official measure is exactly what measurement Canada isn’t supplying. If the us congress did want to impose a standard accuracy for dc fast chargers the weights and measures clause plus the commerce clause would give them all the authority they need without encroaching on states rights.
It's not true that all government power belongs to the federal government and that provinces only gain power by devolution from the federal government. The Canadian constitution describes areas of responsibility for both the federal and provincial governments with some shared areas of responsibility.
