Vehicle Power Unit Capacitor Configuration for Starter Load Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In vehicles with stop-idling systems, the restart of the engine places a heavy load on the battery, causing a voltage drop that can malfunction other electric components, and existing solutions do not adequately reduce the battery load during starter operation.
Innovation Solution
A vehicle power unit is configured with first and second capacitors and a semiconductor switching element, controlled by a controller to form parallel and series connections with the battery, reducing the load on the battery by supplying power from capacitors during starter operation, especially during cold starts when high torque is required.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery drives the starter during engine restart, then the engine can be started, but the battery experiences heavy load causing voltage drop and reduced lifespan
Solution Approach 1:
The power supply system is segmented into multiple energy storage components: the battery and two capacitors (first capacitor connected in parallel, second capacitor connected in series). During starter operation, the capacitors are configured to supply power separately or in combination with the battery, dividing the total power delivery task and reducing the battery's current burden and voltage drop.
Solution Approach 2:
The capacitors are pre-charged during normal vehicle operation when the engine is running and the alternator is generating power. This preliminary energy storage ensures that when the starter needs to operate, the capacitors are already charged and ready to immediately supply power, reducing the battery's load during the high-demand starter operation.
2Productivity
If the battery supplies large current to the starter, then the engine can be started, but the terminal voltage of the battery drops causing malfunction of other electric components
Solution Approach 1:
The power supply function is segmented between the battery and capacitors. The capacitors, with their low internal resistance, are configured to supply a portion of the starter current, while the battery supplies the remainder. This segmentation prevents the battery from experiencing excessive voltage drop and maintains stable power supply to other electric components during starter operation.
Solution Approach 2:
The capacitors act as intermediary energy storage devices between the battery and the starter. During starter operation, the capacitors are connected to supply power, mediating the high-current demand and protecting the battery from direct exposure to the full starter load, thereby maintaining terminal voltage stability.
3Duration of action of stationary object
If capacitors are used to reduce battery load, then battery lifespan is extended, but the system complexity increases with multiple switches and capacitors
Solution Approach 1:
The capacitors and switching network are designed to perform multiple functions: they supply power to the starter during engine cranking, maintain battery terminal voltage stability, and can be charged from the alternator during normal operation. This multi-functionality justifies the added components by providing comprehensive power management benefits beyond just extending battery lifespan.
Solution Approach 2:
The system employs dynamic switching control through the controller and multiple switches (first switch, second switch, third switch, fourth switch, fifth switch) that can reconfigure the circuit topology in real-time. The switches dynamically connect or disconnect the capacitors in series or parallel configurations based on operational requirements, enabling flexible power delivery while protecting the battery.
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 configuration reduces the current drawn from the battery, extending its lifespan and maintaining stable power supply to other vehicle components by efficiently managing power distribution between the battery and capacitors.
Implementation Method 1
a first capacitor 15 and a second capacitor 19. The positive electrode of the first capacitor 15 is connected to the positive electrode of the battery 11 via a first switch 13. The negative electrode of the first capacitor 15 is connected to ground 10A. A second switch 17 is connected to the positive electrode of the first capacitor 15. The negative electrode of the second capacitor 19 is connected to the positive electrode of the first capacitor 15 via the second switch 17
Implementation Method 2
A semiconductor switching element is connected to the positive electrode of the second capacitor 19, and configured to connect and disconnect between the positive electrode of the battery 11 and the positive electrode of the second capacitor 19
Data Source
AI summary
A vehicle power unit is operable to, when not driving the starter, charge first and second capacitors. A controller is operable to, when driving the starter, cause the battery to supply power to the starter if a total voltage of first and second capacitor voltages is smaller than a predetermined total voltage. The controller is operable to, when driving the starter, form a parallel circuit of the battery and the first capacitor, and connect the second capacitor in series to the parallel circuit if the total voltage is not smaller than the predetermined total voltage at a beginning of use of the vehicle. The controller is operable to, when driving the starter, disconnect the battery from the starter. The vehicle power unit reduces a load applied to the battery when driving the starter, accordingly extending a life time of the battery.