Electric Oil Pump Controller Thermal Protection Logic
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The mechanically and electrically integrated electric oil pump faces issues with high board temperatures exceeding the heat resistance limit of the CPU, leading to potential failure or damage, and conventional self-protection controls result in prolonged downtime and oil pressure drops, affecting fuel consumption and transmission mechanisms.
Innovation Solution
A power supply controller that includes a board temperature sensor and an oil temperature sensor, allowing for energization prohibition control when the board temperature exceeds a threshold, and cancellation determination based on oil temperature, ensuring safe operation and reducing downtime by using a series configuration of oil pumps to manage temperature effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the CPU operation is stopped when temperature exceeds the predetermined temperature, then the CPU temperature is prevented from reaching the heat resistance limit, but the time during which the electric oil pump cannot be controlled increases, resulting in deteriorated fuel consumption
Solution Approach 1:
Power supply prohibition is implemented preliminarily when the board temperature reaches a first threshold value, preventing the CPU from reaching dangerous temperatures. The control unit monitors temperature continuously and restores power when the temperature drops below a second threshold, minimizing the duration of pump shutdown while maintaining CPU safety
Solution Approach 2:
The control unit continuously monitors board temperature through the temperature sensor and dynamically adjusts power supply based on real-time temperature readings. When temperature exceeds the first threshold, power is prohibited; when it drops below the second threshold, power is restored. This feedback mechanism optimizes the balance between CPU protection and pump operational efficiency, reducing unnecessary shutdown time and improving fuel consumption
2Reliability
If the CPU is automatically shut down at high temperature using board temperature information, then the CPU is protected, but the board temperature information cannot be obtained when the CPU is shut down, making it impossible to accurately detect or infer the subsequent change of board temperature and confirm that the temperature has dropped sufficiently
Solution Approach 1:
The control unit prohibits power supply to the driver preliminarily when the board temperature reaches the first threshold value, preventing CPU shutdown and the associated loss of temperature monitoring capability. This ensures continuous temperature detection throughout the protection process
Solution Approach 2:
The control unit continuously monitors board temperature through the temperature sensor and compares readings with predetermined thresholds. This continuous feedback ensures accurate temperature detection and enables precise determination of when the temperature has dropped sufficiently to restore safe CPU operation
3Reliability
If the CPU is automatically shut down by self-protection control, then the CPU is protected from damage, but the oil pressure supplied from the electric oil pump suddenly decreases, which may cause damage to the driving force transmission mechanism
Solution Approach 1:
The control unit prohibits power supply to the driver before the CPU reaches a dangerous temperature state. By implementing protection preliminarily at a lower temperature threshold, the system avoids sudden CPU shutdown and the associated abrupt oil pressure drops that could damage the transmission mechanism
Solution Approach 2:
The control unit implements a gradual protection strategy by prohibiting power supply at a first threshold temperature that is lower than the CPU heat resistance limit. This cushioning approach prevents sudden transitions and maintains smoother oil pressure changes, protecting the transmission mechanism from shock loads while still safeguarding the CPU
Data Source
AI summary
A power supply controller includes a driver having a circuit board and controlling an operation of an electric oil pump, a control unit controlling power supply to the driver, a board temperature sensor detecting a temperature of the circuit board; and an oil temperature sensor detecting a temperature of a working oil of a transmission as an oil temperature. The control unit executes energization prohibition control for prohibiting power supply to the driver when the temperature of the circuit board detected by the board temperature sensor exceeds a predetermined first threshold temperature, and executes cancellation determination for determining whether to cancel the energization prohibition control based on the oil temperature detected by the oil temperature sensor during execution of the energization prohibition control.