Brushless Alternator Field Winding Switching for Thermal Control
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Solution Overview
Problem
Overheating of internal components in alternators, particularly at high ambient temperatures and low RPMs with high electrical loads, is a challenge in both brushed and brushless alternators due to insufficient cooling air movement.
Innovation Solution
A brushless alternator assembly with a claw pole rotor and cylindrical stator, featuring a field coil with switching arrangements that connect field windings in series or parallel configurations, and a sensor assembly to manage temperature through switching configurations, and a boost controlling module to adjust magnetic flux.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the alternator operates at high electrical loads, then the electrical output is improved, but the temperature increases causing overheating
Solution Approach 1:
The patent applies dynamics by making the field winding configuration adjustable between series and parallel connections. This dynamic reconfiguration allows the alternator to adapt its magnetic flux output and electrical characteristics based on operating conditions, enabling it to deliver high electrical output when needed while managing thermal conditions through controlled field excitation levels.
Solution Approach 2:
The patent changes the electrical parameters of the field windings by switching between series and parallel configurations. This parameter change directly affects the current flow and magnetic flux generation, allowing the system to optimize performance across different load conditions while preventing overheating by reducing field excitation when temperatures rise.
2Adaptability or versatility
If the ambient temperature is high, then the operating environment is constrained, but the alternator performance deteriorates due to insufficient cooling
Solution Approach 1:
The patent employs feedback through temperature sensing that monitors the alternator's thermal condition and automatically adjusts the field winding configuration in response. This closed-loop control enables the alternator to adapt to high ambient temperatures by modifying its operational parameters, thereby maintaining reliable performance even in constrained thermal environments.
3Speed
If the cooling air movement is insufficient at low RPMs, then the cooling efficiency is reduced, but the temperature control capability is compromised
Solution Approach 1:
The patent applies self-service by enabling the alternator to automatically regulate its own thermal conditions through the temperature-sensitive switching mechanism. When cooling air movement is insufficient at low RPMs, the system self-adjusts by modifying field winding connections to reduce heat generation, thereby maintaining temperature control capability without external intervention or additional cooling mechanisms.
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
Effectively controls alternator temperature by reducing magnetic flux and output when overheating occurs, maintaining performance and safety under varying conditions.
Implementation Method 1
the field coil structured to be positioned relative to said rotor to generate magnetic flux upon being energized
Implementation Method 2
the field coil comprising at least a first field winding electrically connected with at least a second field winding by a switching arrangement such that in a first operable configuration the switching arrangement operates to electrically connect the first and second field windings in series during energization and in a second operable configuration the switching arrangement operates to electrically connect the first and second field windings in parallel during energization
Data Source
AI summary
A vehicle brushless alternator assembly that includes a claw pole rotor assembly having a pair of opposing pole pieces. The rotor defining an axis of rotation, each of the pole pieces having multiple circumferentially spaced pole fingers extending axially. The pole fingers of the rotor alternating between north and south magnetic polarities upon energization of a field coil. The assembly including a cylindrical stator including armature enveloping the magnetic claw poles, the stator arranged coaxially relative to the drive shaft. The field coil positioned relative to said rotor to generate magnetic flux and the field coil including a first field winding electrically connected with a second field winding by a switch such that: in a first operable configuration the switch operates to electrically connect the field windings in series during energization and in a second operable configuration the switch operates to electrically connect the field windings in parallel during energization.