Power Transmission Sampling Module With Optical Isolation
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Solution Overview
Problem
Conventional multiplex systems for sampling analogue characteristics in power transmission systems are large, heavy, prone to non-linearity errors, and suffer from cross-talk due to the use of large isolating transformers, which also introduce bottlenecks and skew in sampling.
Innovation Solution
A sampling module with separate scaling and isolating circuits, including a sigma-delta modulator for concurrent sampling, reduces the need for transformers, minimizing size, weight, and errors, while allowing for independent sample rates and noise isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional isolating transformers are used for sampling analogue characteristics, then electrical isolation and protection are provided, but the system becomes large, heavy, and prone to cross-talk and non-linearity errors
Solution Approach 1:
The patent replaces the mechanical/electromagnetic isolating transformer with an optical isolation system using light-emitting diodes (LEDs) and photodetectors. The analogue signal is converted to optical signals for transmission across the isolation barrier, eliminating the need for large magnetic transformers while maintaining electrical isolation and protection.
Solution Approach 2:
The patent changes the physical parameter used for signal transmission from electromagnetic (transformers) to optical (LEDs and photodetectors). This parameter change enables compact, lightweight isolation without the magnetic core and windings that make traditional transformers large and heavy.
2Reliability
If conventional isolating transformers are used for sampling analogue characteristics, then electrical isolation is achieved, but cross-talk and non-linearity errors increase
Solution Approach 1:
The patent replaces the electromagnetic coupling of isolating transformers with optical coupling using LEDs and photodetectors. This substitution eliminates magnetic flux leakage and cross-talk between adjacent channels, providing cleaner signal transmission and improved measurement precision.
Solution Approach 2:
The patent extracts the signal transmission function from the isolating transformer and separates it into distinct optical components (LED transmitter and photodetector receiver). This separation allows for better signal integrity and reduced interference, improving sampling accuracy.
3Device complexity
If multiplex sampling is used to reduce component count, then system complexity is reduced, but sampling skew and bottlenecks are introduced
Solution Approach 1:
The patent segments the sampling system into multiple independent parallel channels, each with its own optical isolation and ADC. This segmentation allows simultaneous sampling of multiple analogue characteristics without the sequential bottlenecks of multiplexing, eliminating sampling skew while keeping each channel relatively simple.
Solution Approach 2:
The patent transitions from sequential multiplex sampling to parallel concurrent sampling by adding spatial dimensionality with multiple independent channels. Each channel operates independently in parallel, eliminating the time-based bottlenecks of multiplexing while distributing complexity across multiple simple identical units.
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 solution results in a more compact, accurate, and efficient sampling system with reduced cross-talk and non-linearity errors, enabling concurrent sampling of multiple characteristics with finer resolution and improved noise resistance.
Implementation Method 1
an isolating circuit for creating an electrical barrier between respective upstream and downstream portions of the input circuit
Implementation Method 2
A sampling module with separate scaling and isolating circuits, including a sigma-delta modulator for concurrent sampling
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a sampling module (30), for sampling one or more analogue characteristics of a power transmission system, comprising at least one input circuit for sampling a respective analogue characteristic, the or each input circuit including: a scaling circuit (34) for reducing the magnitude of the analogue characteristic to a desired level; an isolating circuit (40) for creating an electrical barrier between respective upstream and downstream portions of the input circuit; and an analogue to digital converter (22) for digitising the analogue characteristic to produce a digital data stream, the scaling circuit (34) being electrically connected to an input of the analogue to digital converter (22) and the isolating circuit (40) being electrically connected directly to an output thereof.