Active Decoupling Impedance for Smart Meter Signal Stability
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Solution Overview
Problem
Devices connected to power lines, such as smart meters and active filters, face signal attenuation and transmission errors due to low load impedance, which existing passive solutions like choke networks cannot adequately address without introducing power losses.
Innovation Solution
An active decoupling impedance system using a transformer with a primary winding connected to the power line and a burden network on the secondary winding, which presents a low impedance at power frequency and a higher impedance in a specific frequency band, preventing signal attenuation and noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a choke network is used to increase impedance in the frequency band above power frequency, then signal attenuation is reduced, but power losses are introduced
Solution Approach 1:
The patent applies dynamics by making the burden network impedance variable with frequency. The active burden network dynamically adjusts its impedance based on the frequency of the signal, presenting low impedance at power frequency to minimize power losses and high impedance in the PLC frequency band to prevent signal attenuation. This dynamic impedance adjustment resolves the contradiction between reducing power losses and preventing signal attenuation.
Solution Approach 2:
The patent changes the impedance parameter of the burden network based on frequency. By using an active circuit that modifies its electrical characteristics according to frequency, the system achieves low impedance at 50/60 Hz (reducing power losses) and high impedance at PLC frequencies (preventing signal attenuation). This parameter change approach allows the same component to serve dual purposes without the trade-off inherent in fixed impedance solutions.
2Reliability
If a large choke is used to prevent core saturation, then saturation is avoided, but device size and cost increase
Solution Approach 1:
The active burden network dynamically controls the magnetic flux in the transformer core by adjusting its impedance with frequency. At power frequency, the low impedance allows controlled current flow that prevents core saturation without requiring excessive core size. This dynamic control enables the use of a smaller, more cost-effective transformer core compared to what would be needed with a passive choke network.
Solution Approach 2:
The patent replaces the mechanical/passive approach of using a large physical choke to prevent saturation with an active electronic control system. The active burden network uses electronic circuitry to control the magnetic flux and prevent saturation, substituting electronic control for the mechanical solution of simply increasing core size. This reduces device size and complexity while maintaining reliability.
3Stability of the object's composition
If passive attenuation network is used to isolate victim device from impedance variation, then impedance stability is improved, but signal attenuation increases
Solution Approach 1:
The active burden network provides dynamic impedance stabilization that adapts to different frequency components. It presents frequency-dependent impedance that stabilizes the total impedance seen by the victim device across varying load conditions, while simultaneously minimizing signal attenuation through its active control mechanism. This dynamic approach overcomes the fixed trade-off of passive networks.
Solution Approach 2:
The active burden network employs feedback control to maintain impedance stability. By monitoring the electrical conditions and actively adjusting its impedance output, the system stabilizes the impedance seen by the victim device while compensating for load variations. This feedback mechanism allows the system to maintain impedance stability without the signal attenuation penalties of passive networks.
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 solution stabilizes the line impedance, improves signal-to-noise ratio, and prevents core saturation, allowing for efficient communication and reduced power losses by introducing an additional resistive impedance in the targeted frequency band.
Implementation Method 1
an active decoupling impedance (20) comprising a transformer (25) having a primary winding connected on an electrical power line (35)
Data Source
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Figure 8
AI summary
An active decoupling device for stabilizing the impedance on an electric line in a determined band of frequency. The decoupling device of the invention is inductively coupled to the power line and comprises a transformer with a primary winding connectable to the power line, and a secondary winding closed on a burden network. In an application, the invention, is used to decouple a smart meter from variations of the load impedance.