Semiconductor Relay Switching for EV Charging Short-Circuit Interruption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing charging systems for electric vehicles require complex control mechanisms and cooling systems to manage short-circuit currents during quick charging, which increases costs and complicates the charging process.
Innovation Solution
A switching device using a semiconductor relay with a controller and sensors to detect and interrupt short-circuit currents without the need for additional cooling mechanisms, by controlling the relay based on current or voltage measurements and external control signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a diode and bypass line with cooling mechanism are used to prevent short-circuit current, then short-circuit prevention is achieved, but device complexity and cost increase
Solution Approach 1:
The invention extracts the short-circuit prevention function from the complex diode-bypass-cooling system and implements it through a semiconductor relay with integrated control. The controller monitors voltage differences and directly controls the relay to open the charging line when short-circuit is detected, eliminating the need for separate cooling mechanisms and bypass lines.
Solution Approach 2:
The invention replaces the mechanical/thermal cooling system with an electronic control system. Instead of using physical cooling mechanisms to manage heat from diodes, the system uses a controller and semiconductor relay to electronically detect and interrupt short-circuit currents, substituting thermal management with electronic control.
2Measurement precision
If voltage sensors and complex control logic are used to detect insulation failure, then detection accuracy is improved, but device complexity increases
Solution Approach 1:
The invention uses feedback control where the controller continuously monitors the voltage difference between charged and uncharged lines and adjusts the relay state accordingly. When the voltage difference exceeds a threshold indicating insulation failure, the controller feedbacks a control signal to open the relay, creating a simple closed-loop detection and response system.
Solution Approach 2:
The controller performs multiple functions: it monitors voltage differences for insulation failure detection, controls the semiconductor relay for short-circuit prevention, and manages the overall charging process. This multi-functionality eliminates the need for separate dedicated detection circuits and simplifies the overall system architecture.
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 prevents short-circuit currents without additional cooling, simplifies control processes, and reduces costs by using a semiconductor relay with low ON resistance, allowing for prompt interruption of short-circuit currents and maintaining normal charging operations.
Implementation Method 1
a semiconductor relay disposed on the transmission path
Implementation Method 2
a sensor configured to measure a current flowing through the semiconductor relay, or a voltage of the semiconductor relay
Data Source
AI summary
A switching device is mounted in a vehicle, and disposed between a connector connected to a DC power source, and a storage battery. The switching device includes: a transmission path connecting the connector and the storage battery; a semiconductor relay disposed on the transmission path; a switch disposed on the transmission path; a first sensor configured to measure a current flowing through the semiconductor relay, or a voltage of the semiconductor relay; and a controller configured to control opening and closing of the semiconductor relay. The switch is controlled by an external control signal, and the controller controls the semiconductor relay, based on the control signal and a measurement value of the first sensor.