Vehicle Charging Converter Reverse Current Blocking for Insulation Faults
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Vehicles with high-voltage accumulators face safety risks due to insulation faults between the high-voltage network and vehicle ground, leading to potential hazardous touch voltages during charging, which existing insulation monitors may not adequately address.
Innovation Solution
Incorporating a reverse current blocking device in the charging voltage converter to prevent unlimited current flow from the high-voltage network to ground, using a unidirectional or bidirectional design with inductors and transistors to limit current flow and enable immediate protective measures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a grounding connection is provided for safety during charging, then user protection against insulation faults is improved, but hazardous touch voltage can still arise if the ground connection is deficient or has high resistance
Solution Approach 1:
The patent introduces a reverse current blocking device as an intermediary element between the high-voltage network and the grounding connection. This device acts as a mediator that allows normal grounding current to flow while blocking reverse current that would create hazardous touch voltages in case of insulation faults, thus resolving the contradiction between providing safety protection and preventing harmful effects.
2Difficulty of detecting and measuring
If insulation monitors are used to detect insulation faults, then fault detection capability is improved, but the reaction time is insufficient to prevent damage to users
Solution Approach 1:
The reverse current blocking device is installed in advance in the grounding path, performing a preliminary protective action before any insulation fault can occur. This passive protection mechanism is already in place and immediately blocks hazardous reverse currents without requiring detection or reaction time, thus resolving the time delay problem of active monitoring systems.
3Quantity of substance
If the grounding conductor has large cross section to handle charging current, then current carrying capacity is improved, but the conductor can still be damaged by unlimited current flow during insulation faults
Solution Approach 1:
The reverse current blocking device serves as a protective intermediary that limits the current flow through the grounding conductor. It allows sufficient current for normal charging operations while blocking unlimited reverse current during insulation faults, thus protecting the grounding conductor from damage without reducing its current carrying capacity.
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 reduces hazardous current flow and allows for timely identification and execution of safety measures, protecting users and preventing damage to grounding conductors.
Implementation Method 1
The reverse current blocking device is designed to conduct current only in one direction
Implementation Method 2
one of the working inductors at least initially limits the current flow (according to the jump response of the inductor)
Data Source
AI summary
A charging voltage converter on a vehicle is equipped with an upstream circuit, which includes at least one working inductor. Furthermore, the converter has a switching unit, which is connected downstream of the upstream circuit. The working inductor connects a first input potential of an input of the voltage converter to the switching unit. A second input potential of the input is connected via a reverse current blocking device of the upstream circuit to the switching unit.