Power Transmission Device Passive Electrode Potential Control

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Solution Overview

Problem

In power transfer systems, the passive electrodes are remotely located, leading to high potential relative to ground, causing unnecessary electromagnetic field leakage and corona discharge when a grounded external body is near, especially when the passive electrode's voltage is high.

Innovation Solution

A power transmission device with a potential control section that adjusts the passive electrode's potential to ground level by applying a voltage, using a detection electrode and an auxiliary high-frequency high-voltage generator, and optionally incorporating a shield electrode connected to ground to suppress electromagnetic field leakage and corona discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the passive electrode is located remotely from the active electrode to enable power transfer, then the power transfer function is achieved, but the potential of the passive electrode becomes excessively high relative to ground potential

Engineering Contradiction:
Improvepower transfer functionVSAvoidhigh potential of passive electrode
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A potential control electrode is introduced as an intermediary between the passive electrode and ground. This control electrode applies a controlled voltage to counterbalance the high potential of the passive electrode, effectively mediating the potential difference and preventing harmful effects while maintaining the remote power transfer configuration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The voltage applied to the passive electrode is dynamically adjusted by the potential control electrode. By changing the voltage parameter of the passive electrode through the control electrode, the system maintains effective power transfer while suppressing the excessive potential relative to ground, thus resolving the contradiction.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the passive electrode voltage is increased to improve power transfer efficiency, then power transfer efficiency is improved, but corona discharge occurs when grounded external bodies are nearby

Engineering Contradiction:
Improvepower transfer efficiencyVSAvoidcorona discharge
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The potential control electrode serves as a mediator that applies a counter-voltage to the passive electrode. This control mechanism allows the system to maintain high voltage for efficient power transfer while simultaneously suppressing the potential that would otherwise cause corona discharge with nearby grounded objects.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The potential control electrode applies a preliminary counter-voltage to the passive electrode before corona discharge can occur. By anticipating and counteracting the potential buildup that leads to corona discharge, the system maintains high power transfer efficiency without experiencing the harmful effects of corona discharge.

Inventive Principle:
Principle #9Preliminary anti-action

3Power

If the passive electrode voltage is high to maintain power transfer, then power transfer is maintained, but unnecessary electromagnetic field leakage occurs

Engineering Contradiction:
Improvepower transferVSAvoidelectromagnetic field leakage
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The potential control electrode dynamically adjusts the voltage parameter of the passive electrode. By controlling the potential of the passive electrode through this mechanism, the system maintains the voltage necessary for power transfer while reducing the electromagnetic field leakage that would otherwise occur due to excessively high potential.

Inventive Principle:
Principle #35Parameter 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

The solution effectively controls the passive electrode's potential to ground level, reducing electromagnetic field leakage and preventing corona discharge, thereby enhancing the safety and efficiency of power transfer.

Implementation Method 1

The active electrode 3 of the power transmission device and the active electrode 6 of the power reception device are located in proximity to each other via a gap 4, so that the two electrodes are capacitively coupled to each other.

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

The potential control section has, for example, an auxiliary high-frequency high-voltage generator which generates a voltage to be applied to the power transmission device's passive electrode.

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP2707940B1Power transmission device and power transfer system
Publication Date: 2016.08.10 MURATA MFG CO LTD
  • EP2707940B1 patent drawingFigure 1~2
  • EP2707940B1 patent drawingFigure 3(A)~4
  • EP2707940B1 patent drawingFigure 5~6

AI summary

A power transmission device and a power transfer system are constructed which suppress the leakage of unnecessary electromagnetic field from a passive electrode of a power reception device as well as the occurrence of corona discharge. The power transmission device includes a high-frequency high-voltage generating circuit (13) which applies a high voltage of high frequency between a power transmission device side active electrode (11) and a power transmission device side passive electrode (12), the power transmission device side passive electrode (12) being disposed in a manner to surround the power transmission device side active electrode (11) and the high-frequency high-voltage generating circuit (13). An auxiliary high-frequency high-voltage generating circuit (33) is provided between a ground of the power transmission device (101) having a potential substantially equal to the ground potential and the power transmission device side passive electrode (12). The auxiliary high-frequency high-voltage generating circuit (33) suppresses a potential change of the power reception device side passive electrode (22) relative to the ground potential.