Vehicle Dual Alternator Voltage Transient Control
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Solution Overview
Problem
Modern vehicles with dual alternators experience voltage transients when large loads are turned on or off, leading to potential system failures, warnings, and abnormal operations due to the mechanical nature of alternators, which cannot immediately adjust to rapid changes in power demand.
Innovation Solution
A processor-controlled system that detects increasing loads at a threshold rate, reduces voltage setpoints, and turns off secondary alternators to mitigate voltage transients, then reactivates them once the transient has passed, thereby managing power consumption and maintaining stable voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If dual alternators are used to provide sufficient power for high-power loads, then power supply capacity is improved, but voltage transients occur when loads change rapidly
Solution Approach 1:
The control system performs preliminary action by detecting when a load exceeds the threshold and proactively reducing the voltage setpoint of the second alternator before the voltage transient occurs. This preventive measure allows the alternators to maintain stable voltage output during rapid load changes, resolving the contradiction between providing sufficient power capacity and maintaining voltage stability.
2Power
If the second alternator remains on during rapid load changes, then power availability is maintained, but voltage transients cause system failures or abnormal operations
Solution Approach 1:
The control system extracts the second alternator from the power supply system during periods when rapid load changes are detected. By taking the second alternator out of service temporarily (reducing its voltage setpoint to zero), the system eliminates the source of voltage transients while maintaining power availability through the first alternator, thus resolving the contradiction between power availability and preventing harmful voltage transients.
3Reliability
If the voltage setpoint of the second alternator is reduced proactively, then voltage stability is improved, but the second alternator may be unnecessarily turned off during normal operation
Solution Approach 1:
The control system uses feedback by continuously monitoring the load level and the rate of change of the load. The processor compares the current load against the threshold and the rate of change against the threshold rate, and only reduces the second alternator's voltage setpoint when both conditions indicate a rapid load change is occurring. This feedback mechanism ensures the second alternator is turned off only when necessary for voltage stability, maintaining high productivity during normal operation.
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 effectively reduces the magnitude of voltage transients, preventing system failures and ensuring smooth operation by proactively adjusting alternator output and re-engaging secondary alternators after the transient has expired, thus enhancing the reliability of power management in vehicles with high-power loads.
Implementation Method 1
An alternator may include a rotor configured to create a rotating magnetic field and a stator configured to capture the magnetic field and convert the rotational energy of the rotating magnetic field to an AC or DC current
Implementation Method 2
When a load is quickly removed, the alternator has a period of time where the inertia of the system will cause the alternator to continue producing the voltage needed to run the load even with the load being disconnected from the system
Data Source
AI summary
System and method are disclosed for power management in a vehicle having two or more alternators. An example vehicle power system includes first and second alternators, and a processor. The processor is configured to determine that a load coupled to the first and second alternators increases at greater than a threshold rate. The processor is also configured to responsively (i) reduce respective voltage setpoints of the first and second alternators, and (ii) turn off the second alternator. And the processor is further configured to, after determining that a voltage transient caused by the load has expired, turn on the second alternator.