Method and system for coolant flow control for a prime mover in a vehicle propulsion system

Abstract

A vehicle propulsion system includes a prime mover having a coolant inlet and coolant outlet, a coolant flow controller having a flow control inlet in communication with the prime mover coolant outlet, and a flow control outlet in communication with the prime mover coolant inlet, and a controller that determines a coefficient based upon a power of the prime mover, and that provides a coolant flow command signal to the coolant flow controller based upon the power of the prime mover.

Description

FIELD[0001]The present disclosure relates to a method and system for coolant flow control for a prime mover in a vehicle propulsion system.INTRODUCTION[0002]This introduction generally presents the context of the disclosure. Work of the presently named inventors, to the extent it is described in this introduction, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against this disclosure.[0003]Vehicle propulsion systems may control coolant flow for a prime mover based on a predetermined set of gain coefficients that are determined by operating the prime mover at steady state in a number of operating conditions and determining the optimum set of gain coefficients for each operating condition. For example, in an internal combustion engine having a flow of coolant controlled by a valve, the engine may be operated at a selected speed and load and the proportional and integral ...

AI Technical Summary

Benefits of technology

[0014]In this manner, by selecting control system coefficients based upon a power of the prime mover, control over the temperature of a prime mover in a vehicle propulsion system is greatly improved, which, in turn, improves fuel economy, efficiency, performance, reliability, and durability, reducing actuator oscillations and temperature fluctuations, improving responsiveness, reducing thermal strain, while simultaneously significantly reducing the workload associated with a calibration process that determines the coefficients corresponding to the power of the prime mover.

Problems solved by technology

An overdamped system may result in a coolant flow temperature which is very slow to respond.

An underdamped system may result in a coolant flow temperature which repeatedly overshoots and undershoots the target temperature and may generally be unstable.

An underdamped system will tend to overwork the components in the coolant flow control system which may lead to excessive wear and reduced durability.

Further, an underdamped coolant temperature control may lead to excessive thermal cycling which may have an adverse effect on the components of the coolant system.

However, the calibration workload that is required also necessarily increases with the number of operating conditions for which optimum gain coefficients are determined in this manner.

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