Multiphase Converter Phase Control for Low-Temperature Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multiphase converters face output restrictions due to low cooling medium temperatures, which reduce the withstand voltage of switching elements, limiting the output voltage and affecting the performance of electric vehicles.
Innovation Solution
A multiphase converter system with a controller that adjusts the number of active converters and output voltage limits based on cooling medium temperature, increasing the number of phases and heating to restore original withstand voltage characteristics when temperatures are low, and switching back to normal operation when temperatures rise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the number of phases is increased to disperse thermal load when switching element temperature exceeds threshold, then the thermal load of switching elements is reduced, but the output voltage upper limit is restricted due to low cooling medium temperature
Solution Approach 1:
The patent converts the harmful low temperature condition into a beneficial heating opportunity by driving more phases than normally required. The additional phase operation generates heat that warms the cooling medium, and once the cooling medium temperature reaches the predetermined threshold, the full output voltage capability becomes available. This transforms the temperature restriction from a limiting factor into a self-correcting mechanism.
Solution Approach 2:
The patent dynamically adjusts the number of driven phases based on real-time cooling medium temperature. When the cooling medium temperature is below the threshold, more phases are driven to generate heat; when the threshold is reached, the system transitions to normal phase operation. This dynamic adjustment allows the system to adapt to temperature conditions and restore full output capability.
2Temperature
If more converters are driven to increase heating value when cooling medium temperature is low, then the temperature of cooling medium is increased quickly, but the device complexity and control difficulty increase
Solution Approach 1:
The patent implements a feedback control mechanism where the controller continuously monitors the cooling medium temperature and compares it with a predetermined threshold. Based on this feedback, the controller automatically adjusts the number of driven phases. This closed-loop control simplifies the decision-making process and reduces control complexity by using a clear temperature-threshold-based strategy.
Solution Approach 2:
The patent changes the operational parameter (number of driven phases) based on the temperature parameter. By establishing a predetermined temperature threshold, the system transforms a complex control problem into a simple parameter adjustment task: when temperature < threshold, drive m phases; when temperature ≥ threshold, drive n phases. This parameter-based control approach reduces device complexity.
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
This approach allows the multiphase converter to quickly increase cooling medium temperature, restoring the original withstand voltage and output capabilities, ensuring efficient operation and drivability of electric vehicles even at low temperatures.
Implementation Method 1
In the cooler, a cooling medium flows so as to cool the multiphase converter
Implementation Method 2
a cooling medium flows so as to cool the multiphase converter
Data Source
AI summary
A multiphase converter system includes a multiphase converter in which a plurality of converters are connected in parallel; a cooler in which a cooling medium flows so as to cool the multiphase converter; a temperature sensor configured to measure a temperature of the cooling medium; and a controller. The controller is configured to drive the converter for n phase or the converters for n phases when a target output of the multiphase converter is lower than a prescribed output threshold and the temperature of the cooling medium falls within a prescribed temperature range, and to drive the converters for m phases when the target output is lower than the prescribed output threshold and the temperature of the cooling medium is lower than the prescribed temperature range, m being larger than n.