Liquid Cooled Inverter with Predictive Bypass Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing liquid-cooled inverters for electric drive motors in vehicles face inefficiencies in temperature control, leading to increased wear and tear due to thermal stress, as they rely on complex and delayed cooling systems that fail to effectively manage temperature fluctuations, thereby reducing the service life of power stages.
Innovation Solution
A liquid-cooled inverter design featuring a temperature control device with a bypass coolant line and volume flow controller, allowing for predictive cooling by adjusting the cooling capacity based on the operating point and thermal loss predictions, thereby reducing temperature fluctuations and extending the service life of the power unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If temperature-controlled cooling systems are used to regulate coolant flow based on power stage temperature, then energy efficiency is improved, but device complexity increases due to temperature sensors, air conditioning compressors, and flow regulation mechanisms
Solution Approach 1:
The control device adjusts the coolant volume flow through the heat sink in advance based on predicted thermal loss input from the power unit, rather than reacting to actual temperature measurements. This predictive approach allows the cooling system to prepare for upcoming thermal loads, reducing the need for complex temperature sensing and reactive control mechanisms while maintaining energy efficiency.
2Loss of energy
If reactive temperature control is used where coolant flow is adjusted based on detected temperature, then cooling capacity is optimized, but reliability decreases due to system inertia and delayed response to temperature changes
Solution Approach 1:
The system uses a control device that predicts future thermal loss input based on operating parameters and pre-adjusts the coolant volume flow accordingly. This eliminates the time delay inherent in reactive temperature control systems, allowing the cooling capacity to be optimized in advance while ensuring reliable temperature management that protects the power stage from thermal stress.
3Reliability
If constant coolant flow is used through the heat sink, then cooling reliability is improved, but energy efficiency decreases due to unnecessary cooling when thermal loss is low
Solution Approach 1:
The control device dynamically adjusts the coolant volume flow through the heat sink based on predicted thermal loss input from the power unit. Instead of maintaining constant flow, the system varies the flow rate to match actual cooling needs, improving energy efficiency while maintaining adequate cooling reliability through predictive control based on operating conditions.
Solution Approach 2:
The system changes the operating parameter of coolant volume flow based on predicted thermal conditions. By adjusting the flow rate parameter according to anticipated thermal loss input, the system achieves energy efficiency improvements while maintaining cooling reliability through adaptive parameter modification rather than constant operation.
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
The solution enables precise control of cooling power, reducing both absolute temperatures and temperature fluctuations, thereby enhancing the service life of the power unit by anticipating and adjusting cooling capacity according to the operating conditions, thus improving the reliability and efficiency of the inverter.
Implementation Method 1
a cooling liquid flowing through a heat sink onto which an underside of the substrate is applied
Implementation Method 2
Part of the heat loss occurring in the inverter is absorbed by the coolant and transported away
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a liquid-cooled inverter (1) for controlling an electric drive motor of a vehicle. The inverter (1) comprises a power unit (2) having a circuit arrangement comprising power semiconductor elements (4) arranged on the upper side of a substrate (3). The inverter (1) further comprises a temperature control device (5) for cooling the power unit (2). The temperature control device (5) has a heat sink (6) through which a coolant flows, and on which an underside of the substrate (3) is applied. The temperature control device (5) further comprises a main coolant section (7) which extends at least partially through the heat sink (6) and a bypass coolant line (8) branching off from the main coolant line (7) to reduce the cooling power transferred to the power unit (2).The temperature control device (5) further comprises a volume flow controller (9) configured to adjust the volume flow fraction (10) of the coolant diverted from the main coolant line (7) into the bypass coolant line (8) in order to influence the cooling capacity transferred from the temperature control device (5) to the power unit (2). The invention further relates to a motor vehicle, preferably a commercial vehicle, comprising the liquid-cooled inverter (1).