abstract |
This disclosure relates to a method for preventing or minimizing electrostatic discharge and dielectric breakdown in an electric vehicle powertrain by controlling electrical conductivity over a lifetime of a lubricating oil in an electric vehicle powertrain lubricated with the lubricating oil. The lubricating oil has a composition including a lubricating oil base stock as a major component, and an additive package as a minor component comprising one or more lubricating oil additives, and an effective amount of one or more conductivity agents, as a minor component. The lubricating oil has an electrical conductivity from 10 pS/m to 20,000 pS/m, a dielectric constant of 1.6 to 3.6, with a ratio of electrical conductivity-to-dielectric constant from 1,000 to 10,000. Also provided are methods for obtaining a desired electrical conductivity-to-dielectric constant ratio of a lubricating oil for an electric powertrain and powertrain components and methods for lubricating an electric vehicle powertrain and powertrain components. |