Vehicle Power Control Unit for DC Link Overload Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In vehicles with a DC voltage intermediate circuit and drive motors, excessive power consumption or output due to control behavior deviations can lead to overloading of the storage device, triggering protection device tripping and potentially taking the vehicle out of operation.
Innovation Solution
A power specification device that adjusts the maximum engine power by starting with a lower value and increasing it only when actual engine power conditions are met and storage current remains below a maximum value, ensuring the power limitation value is not exceeded, thus preventing overloading of the storage device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the power limit value is set to the maximum power value, then the drive motor can deliver maximum power, but the storage device may be overloaded due to tolerance deviations in control behavior
Solution Approach 1:
The power control device performs preliminary action by setting the power limit value below the maximum power value before the storage device could be overloaded. This preventive approach ensures that even with control deviations, the storage device operates within safe current limits, avoiding tripping and maintaining system reliability.
2Reliability
If the power limit value is reduced below maximum, then storage device overload is prevented, but the drive motor cannot deliver full power
Solution Approach 1:
The power control device applies dynamics by continuously monitoring storage current and dynamically adjusting the power limit value. When storage current is below the maximum threshold, the power limit is increased toward the maximum power value, allowing full power delivery. This dynamic adaptation resolves the contradiction by enabling both protection and full power output under different operating conditions.
3Power
If the power limit value is dynamically adjusted, then both power optimization and storage protection are achieved, but the control system complexity increases
Solution Approach 1:
The power control device uses feedback by monitoring the storage current and using this information to adjust the power limit value. The control device receives feedback about storage device status and modifies the power limit accordingly, enabling automated optimization without requiring complex manual intervention or sophisticated control algorithms.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates, among other things, to a vehicle (10) with a DC link (50), at least one drive motor (60) connected to the DC link (50), a motor control unit (100) controlling the drive motor (60), and at least one electrical storage device (110) connected to the DC link (50). According to the invention, a power control unit (LVGE) is provided, which transmits a power limit value (PW) specifying the maximum motor power to the motor control unit (100). The power control unit (LVGE) comprises a power increase unit (LEE) which, after each reset, generates a starting value (SW) as the target value (VW) that is lower than a predetermined maximum power value (Pmax), and subsequently increases the target value (VW) up to a maximum of the maximum power value (Pmax).as long as a predetermined motor-power-related increase condition (EB) is met and simultaneously the storage current (Iist) is below a predetermined maximum current value (Imax), and the power control device (LVGE) transmits the target value (VW) or a modified target value (VW') derived therefrom to the motor control unit (100) as the power limit value (PW) specifying the maximum motor power, and the motor control unit (100) is designed in such a way that it limits the motor power to an actual motor power value, taking into account the power limit value (PW).