Vehicle Auxiliary Power Supply Voltage Control During Battery Disconnect
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle power supply systems using a DC-DC converter as the sole power source for auxiliary loads when a switch is interrupted face significant voltage fluctuations due to changes in power demand, particularly when a lithium-ion battery is used as the auxiliary battery.
Innovation Solution
A vehicle power supply device with a DC-DC converter, an auxiliary battery, a switch, and control units that manage the connection state of the switch and adjust the DC-DC converter's output voltage to maintain stable power supply even when the switch is interrupted.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the switch is interposed between the auxiliary battery and DC-DC converter to protect the lithium-ion battery, then the auxiliary battery can be protected from overcharge or damage, but when the switch is in an interrupted state, the power supply voltage readily varies under effects of great change in electric power demand for the auxiliary load
Solution Approach 1:
The control unit dynamically changes the output voltage parameter of the DC-DC converter based on the switch state. When the switch is interrupted, the control unit increases the DC-DC converter's output voltage to compensate for the loss of auxiliary battery support, thereby maintaining stable power supply voltage despite variations in auxiliary load demand
2Adaptability or versatility
If the switch is in a conducting state, then both the auxiliary battery and DC-DC converter serve as power supply sources, but when the switch is in an interrupted state, only the DC-DC converter remains as the power supply source
Solution Approach 1:
The system dynamically adjusts the DC-DC converter's output voltage according to the switch state and auxiliary load conditions. When the switch transitions from conducting to interrupted state, the control unit increases the converter's output voltage to compensate for the reduced power supply capacity, ensuring continuous stable operation of auxiliary loads
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 system stabilizes power supply voltage by controlling the DC-DC converter output to a higher level when the switch is disconnected, preventing voltage fluctuations and ensuring stable operation of auxiliary loads despite changes in power demand.
Implementation Method 1
a DC-DC converter that is provided between the power supply source and the auxiliary loads, and that controls electric power supply from the power supply source to the auxiliary loads
Implementation Method 2
an auxiliary battery, including a lithium-ion battery that is chargeable by the power supply source
Data Source
AI summary
A vehicle power supply device for supplying electric power to a plurality of auxiliary loads mounted on a vehicle, comprising: a power supply source; an auxiliary battery including a lithium ion battery chargeable by the power supply source; a DDC provided between the power supply source and the plurality of auxiliary loads and controlling the power supply from the power supply source to the plurality of auxiliary loads; a switch provided between DDC and the plurality of auxiliary loads and the auxiliary battery, and switching an electrically connected status between the plurality of auxiliary loads and the auxiliary battery; and a control unit for controlling DDC and the switch, wherein the control unit controls the output voltage of DDC to be higher in the second voltage when the switch is shut off than the first voltage when the switch is turned on.