Power Electronic Apparatus Output Impedance for PLC Interference Control
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Solution Overview
Problem
The increasing use of power electronic apparatuses in power line communication systems causes harmonic interference, affecting PLC communication quality, and existing solutions involving additional passive filters increase costs and are not highly applicable.
Innovation Solution
The power electronic apparatuses are configured to increase output impedance in the PLC communication frequency band by reducing harmonic and interharmonic currents, using a control unit to generate switch signals based on target control voltages, thereby suppressing interference without additional passive filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a filter is connected to the output end of the power electronic apparatus to reduce interference, then PLC communication quality is improved, but system cost and complexity increase
Solution Approach 1:
The patent extracts and eliminates the harmful harmonic currents from the power electronic apparatus output through active control, rather than adding a passive filter. The control unit identifies and suppresses harmonic components in the frequency band of interest, effectively removing the interference source without adding external filtering components.
Solution Approach 2:
The power electronic apparatus performs self-regulation by using its own control unit to detect and suppress harmonic currents generated by its switching operations. The system monitors its own output and actively compensates for interference, making it self-sufficient without requiring additional passive filter components.
2Reliability
If a filter is connected to the output end of the power electronic apparatus to reduce interference, then PLC communication quality is improved, but system cost increases
Solution Approach 1:
The patent extracts and eliminates the harmful harmonic currents from the power electronic apparatus output through active control, rather than adding a passive filter. The control unit identifies and suppresses harmonic components in the frequency band of interest, effectively removing the interference source without adding external filtering components.
Solution Approach 2:
The power electronic apparatus performs self-regulation by using its own control unit to detect and suppress harmonic currents generated by its switching operations. The system monitors its own output and actively compensates for interference, making it self-sufficient without requiring additional passive filter components.
3Productivity
If the switching frequency of the power electronic apparatus is increased, then power conversion efficiency is improved, but harmonic interference in the PLC communication frequency band increases
Solution Approach 1:
The patent converts the harmful harmonic currents generated by high-frequency switching into a controllable parameter. The control unit detects these harmonic components and actively suppresses them, transforming the interference problem into a manageable control task that maintains both high switching frequency and low interference.
Solution Approach 2:
The system dynamically adjusts control parameters to suppress harmonic currents in specific frequency bands. By changing the control strategy based on the detected harmonic content and PLC communication frequency band, the system maintains high switching efficiency while minimizing interference through parameter optimization.
Data Source
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AI summary
This application provides a power line communication system, a power electronic apparatus, and an interference suppression method. The power line communication PLC system includes a PLC signal transmitting end, a PLC signal receiving end, and a power electronic apparatus. The PLC signal transmitting end is connected to the PLC signal receiving end through a power line, and the power electronic apparatus is connected to the power line. The power electronic apparatus is configured to increase output impedance in a first PLC communication frequency band, to reduce interference from an output current of the power electronic apparatus to a PLC signal in the first PLC communication frequency band. The first PLC communication frequency band is a PLC communication frequency band in which the PLC signal transmitting end sends the PLC signal to the PLC signal receiving end. According to embodiments of this application, the interference from the power electronic apparatus to the PLC signal in the first PLC communication frequency band can be reduced without adding an additional passive filter.