Electric Drive Module Pump Control for Cooling and Lubrication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thermal systems in battery electric vehicles (BEVs) inefficiently provide coolant pump flow, leading to insufficient cooling and lubrication, increased operating temperatures, reduced motoring performance, and excessive power consumption, which affects the vehicle's range and reliability.
Innovation Solution
A thermal management system with a controller that adjusts pump speed based on temperature and power loss thresholds, using sensors to determine optimal fluid flow for cooling and lubrication, and incorporates a poppet valve to manage fluid distribution efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coolant pump operates at constant high flow rates, then the EDM is adequately cooled and lubricated, but power consumption increases and vehicle range decreases
Solution Approach 1:
The pump operates at variable speeds rather than constant speed, dynamically adjusting the flow rate based on real-time temperature conditions and power loss requirements, thereby optimizing the balance between cooling adequacy and energy consumption
Solution Approach 2:
The system uses temperature sensors and power loss measurements to continuously monitor system conditions, with the controller adjusting pump speed based on this feedback to maintain adequate cooling while minimizing power consumption
2Use of energy by moving object
If the coolant pump operates at reduced flow rates, then power consumption decreases and vehicle range increases, but cooling and lubrication may become insufficient
Solution Approach 1:
Temperature sensors continuously monitor the EDM components, and the controller adjusts pump speed in response to temperature feedback, ensuring that cooling adequacy is maintained even at reduced flow rates by pumping only when and where needed
Solution Approach 2:
The system directs coolant flow selectively to specific areas of the EDM based on local temperature conditions and power loss requirements, rather than providing uniform flow throughout, thereby maintaining effective cooling with reduced overall flow rate
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enhances cooling effectiveness, reduces power consumption, and maximizes vehicle range by optimizing coolant flow according to the EDM's operating conditions, thereby improving motoring performance and reliability.
Implementation Method 1
The pump delivers fluid through a hydraulic circuit to the electric motor
Implementation Method 2
The first temperature sensor senses a first temperature at the pump. The second temperature sensor senses a second temperature at the sump
Implementation Method 3
The controller is configured to: determine an initial pump flow based on a heat losses associated with a speed and torque of the electric motor; command the pump to operate at an initial speed to satisfy the initial pump flow
Implementation Method 4
EDMs have electric motors that are cooled by thermal systems to prevent overheating
Data Source
AI summary
A thermal management system for an electric drive module configured to generate and transfer drive torque to a driveline for propulsion of an electric vehicle is provided. The system includes a motor housing, a pump, a first and second temperature sensor and a controller. The motor housing has an electric motor and a sump. The pump delivers fluid through a hydraulic circuit to the electric motor. The first temperature sensor senses a first temperature at the pump. The second temperature sensor senses a second temperature at the sump. The controller is configured to: determine an initial pump flow based on a heat losses associated with a speed and torque of the motor; command the pump to operate at an initial speed to satisfy the initial pump flow; compare at least one of the first and second temperatures to a threshold; command the pump to operate at a first modified speed.