Redundant Transformer Test Circuit for Secondary Winding Fault Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transformers used in high-safety position sensors face issues with fault detection due to electrical connections or short circuits between secondary winding packages, which can corrupt measurement results and render redundant modes of operation ineffective.
Innovation Solution
A transformer design with galvanically isolated secondary inductors and a test circuit using DC voltage dividers allows for reliable fault detection and distinction by overlaying specific DC voltage potentials on alternating voltages, enabling discrete access to all secondary inductor terminals and providing distinct test voltages for different fault states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If secondary inductors are arranged redundantly with overlapping windings, then safety and reliability are improved, but fault detection capability deteriorates due to electrical connections between winding packages
Solution Approach 1:
The patent introduces an intermediary test circuit with test voltage sources and evaluation electronics that mediates between the redundant secondary inductors and the control system. This intermediary system enables fault detection by injecting test voltages and evaluating the responses, thereby resolving the contradiction between maintaining redundant overlapping windings for safety and detecting faults in such configurations.
Solution Approach 2:
The transformer performs self-diagnosis through integrated test circuits that continuously monitor the condition of secondary inductors. The system uses its own internal resources (test voltage sources, evaluation electronics) to detect faults without requiring external diagnostic equipment, enabling the redundant system to verify its own integrity and maintain reliability.
2Difficulty of detecting and measuring
If DC voltage potentials are overlaid on alternating voltage for fault detection, then fault states become detectable, but short-circuit faults between non-galvanically connected winding packages cannot be detected
Solution Approach 1:
The patent segments the fault detection process into multiple independent test circuits, each with its own test voltage source and evaluation electronics. By dividing the monitoring function into separate segments for each secondary inductor, the system can detect short-circuit faults between non-galvanically connected winding packages that a single unified test circuit would miss.
Solution Approach 2:
The patent changes the electrical parameters by using different DC voltage potentials for different test circuits and evaluating the responses at different operating points. This parameter variation enables the detection of short-circuit faults that would be invisible at a single voltage level, as different voltage potentials reveal different fault conditions in the redundant secondary inductors.
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 enables comprehensive and reliable fault detection, distinguishing between various fault states, including short circuits and discontinuities, ensuring effective operation even in high-safety applications like electrohydraulic brake systems.
Implementation Method 1
a primary circuit with a primary inductor, a first secondary circuit with a first secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor, a second secondary circuit with a second secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor
Data Source
AI summary
A transformer including a primary circuit with a primary inductor, a first secondary circuit with a first secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor, a second secondary circuit with a second secondary inductor that is galvanically isolated from the primary inductor and coupled to the primary inductor. The second secondary inductor is implemented redundantly with respect to the first secondary inductor, in particular such that the first secondary inductor encloses the second or the second encloses the first. The first and second secondary inductors are connected to one, or each to one, DC voltage source as well as each to a test circuit with a tapping point for tapping off a test voltage.