Vehicle Generator Current Detection via Rectifier Voltage Drop
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Solution Overview
Problem
Conventional vehicle generators with current detectors have high production costs and weight due to their complex and heavy structures, which are not efficiently addressed by existing technologies.
Innovation Solution
A vehicle generator design that detects output current by measuring voltage differences between specific points in the rectifier's current path, using a resistance value and temperature-compensating circuits to calculate the output current, eliminating the need for heavy and complex current detecting components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional current detector with laminated cores and current detecting coil is used, then output current detection function is achieved, but production cost and weight increase
Solution Approach 1:
The patent extracts the current detection function from a separate heavy current detector and integrates it into the rectifier's existing current path section. By utilizing the rectifier's inherent resistance and voltage detection capabilities, the design eliminates the need for additional heavy laminated cores and current detecting coils, achieving current detection without increasing weight.
Solution Approach 2:
The rectifier's current path section is designed to serve multiple functions: it conducts the output current and simultaneously acts as the detection path for voltage measurement. The existing resistance in the current path is utilized for both power transmission and current sensing, eliminating the need for separate detection components.
2Measurement precision
If a conventional current detector with laminated cores and current detecting coil is used, then output current detection function is achieved, but production cost increases
Solution Approach 1:
The patent removes the expensive laminated cores and current detecting coils from the design and extracts the detection function to be performed by the rectifier's existing components. This eliminates the need for additional expensive materials and complex assembly processes, significantly reducing production cost.
Solution Approach 2:
The rectifier's current path section is designed to serve dual purposes: power conduction and current detection. By utilizing the existing resistance and voltage detection capability of the rectifier, the design eliminates the need for separate expensive detection components, reducing overall production cost.
3Weight of stationary object
If voltage detection method is used to eliminate heavy current detecting components, then weight and cost are reduced, but temperature compensation becomes necessary
Solution Approach 1:
The patent introduces a temperature compensation circuit that acts as an intermediary to correct the resistance value based on temperature variations. This compensation mechanism uses the detected temperature to adjust the resistance value, thereby maintaining accurate current detection despite temperature-induced resistance changes in the rectifier.
4Device complexity
If simple voltage detection is used, then device complexity is reduced, but long-term accuracy deteriorates due to component characteristic changes
Solution Approach 1:
The patent implements a feedback mechanism where the output current calculating circuit continuously monitors the voltage difference and adjusts the calculation based on the resistance value and temperature compensation. This feedback loop ensures that even as component characteristics change over time, the system maintains accurate current detection by dynamically adjusting for these changes.
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 design reduces production costs and weight while maintaining accurate output current detection, even under varying temperature conditions, without the need for additional temperature sensors, and allows for long-term accurate measurement by accounting for over-time characteristic changes.
Implementation Method 1
a first voltage detector circuit detecting a voltage difference between two points of the current path section located along a direction in which the output current flows
Implementation Method 2
an output current calculating circuit calculating a value of the output current on the basis of the voltage difference detected by the first voltage detector circuit and a resistance value between the two points of the current path section
Implementation Method 3
a temperature-compensating circuit correcting the resistance value in accordance with a temperature of the rectifier
Data Source
AI summary
The vehicle generator includes a rotor around which a field winding is wound, a stator around which an armature winding is wound, a rectifier rectifying an AC voltage induced in the armature winding to generate a DC output current. The rectifier has a plurality of rectifying elements mounted to a current path section thereof, the DC output current flowing through the current path section to reach an output terminal of the vehicle generator. The vehicle generator further includes a first voltage detector circuit detecting a voltage difference between two points of the current path section located along a direction in which the output current flows, and an output current calculating circuit calculating a value of the output current on the basis of the voltage difference detected by the first voltage detector circuit and a resistance value between the two points of the current path section.