Traction motor controller with dissipation mode

摘要

An apparatus in an electric vehicle including a propulsion electric motor powered by energy from an energy storage system, including a field oriented motor controller generating motor control signals for the electric motor, the motor control signals responsive to a flux command signal and a torque command signal; a torque command calculator, coupled to the motor controller, generating the torque command signal to command a desired torque; an optimal efficiency controller, coupled to the torque command calculator, generating an operating efficiency flux to operate the electric motor at a first determinable efficiency using a first power from the energy storage system while providing the desired torque; an excess dissipation controller generating an inefficient flux to operate the electric motor at a second determinable efficiency using a second power from the energy storage system independent of the desired torque wherein the second power is greater than the first power; and a mode controller setting the flux command signal using one of the optimal efficiency flux and the inefficient flux.

主权项

1. An apparatus in an electric vehicle including a propulsion electric motor powered by energy from an energy storage system, comprising:
a field oriented motor controller generating one or more motor control signals for the propulsion electric motor, said one or more motor control signals responsive to a flux command signal and a torque command signal; a torque command calculator, coupled to said field oriented motor controller, generating said torque command signal to command a desired torque; an optimal efficiency controller, coupled to said torque command calculator, generating an operating efficiency flux to operate the propulsion electric motor at a first determinable efficiency using a first power from the energy storage system while providing said desired torque; an excess dissipation controller generating an inefficient flux to operate the propulsion electric motor at a second determinable efficiency using a second power from the energy storage system, wherein said second power is greater than said first power, and wherein the inefficient flux produces a higher level of power dissipation than the operating efficiency flux; and a mode controller selecting one of an optimal efficiency mode or a dissipation mode as a selected mode wherein said optimal efficiency mode uses said operating efficiency flux as said flux command signal and wherein said dissipation mode uses said inefficient flux as said flux command signal; wherein the apparatus mitigates cold ambient performance degradation of the electric vehicle, wherein the energy storage system provides a heating worthwhile reference temperature signal to the apparatus, the heating worthwhile reference temperature signal indicating a temperature when to heat the energy storage system for improving performance, and wherein selection of the dissipation mode by the mode controller comprises an intentional excess dissipation that increases available power from the energy storage system faster than dissipation-mode consumption of energy decreases the available power from the energy storage system due to reduction in a state of charge of the energy storage system.