Bidirectional Inverter for Uninterruptible EV Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric vehicle (EV) charging systems with energy reinjection functions experience interruptions in power supply to electrical installations due to delays in decoupling from the electrical power network, leading to potential power cuts and stress on the vehicle battery.
Innovation Solution
A control method for an EV charging system that includes a switch and bidirectional AC-DC converters to manage power supply, allowing for uninterruptible power supply mode, charging mode, and power injection mode, where the switch is controlled to seamlessly transition between using the electrical power network and the vehicle's battery, minimizing battery stress and avoiding power cuts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a decoupling device is installed to physically separate the electrical installation from the power supply network, then safety is improved, but the response time to prevent power cuts deteriorates
Solution Approach 1:
The patent introduces a bidirectional inverter as an intermediary device that can operate in both voltage source mode and voltage follower mode. This inverter acts as a mediator between the electrical installation and the power supply network, allowing seamless transition during power failures without requiring physical decoupling devices that cause delays.
Solution Approach 2:
The inverter dynamically switches between two operational modes: voltage source mode (when grid power is available) and voltage follower mode (when grid power fails). This dynamic adaptability allows the system to respond instantly to power failures, eliminating the response time delay associated with static decoupling devices.
2Reliability
If the inverter operates in voltage source mode to supply the electrical installation, then power supply continuity is improved, but the complexity of the control system deteriorates
Solution Approach 1:
The control system periodically monitors the operational status and grid conditions, switching between voltage source mode and voltage follower mode based on real-time requirements. This periodic assessment simplifies control logic compared to continuous complex calculations, while maintaining power supply continuity.
3Use of energy by moving object
If the vehicle battery is used as an energy storage means, then energy efficiency is improved, but the stress on the battery deteriorates
Solution Approach 1:
The bidirectional inverter serves as an intelligent intermediary between the vehicle battery and the electrical installation. It manages charge/discharge cycles optimally, using the battery as energy storage during grid availability and as backup power during failures, thereby reducing unnecessary battery stress while maintaining energy efficiency.
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
Ensures continuous power supply to electrical installations during network disruptions, reduces battery stress, and allows for efficient energy reinjection without modifying the vehicle architecture, thereby enhancing power reliability and battery longevity.
Implementation Method 1
a bidirectional inverter which charges the battery of the electric vehicle and also discharges it
Data Source
Figure 1~2
AI summary
Power supply control system of an electrical installation (4) connected to a power supply network (3) via a charging station (1) connected to an electric or hybrid vehicle (2), the system comprising a first AC-DC converter (5) connected on the one hand to the power supply network (3) and on the other hand to a battery (12) of the vehicle (2), the charging station (1) comprising a second AC-DC converter (6) connected to the electrical installation (4) and to the battery (12) of the vehicle (2), the charging station (1) further comprising a switch (7) connected between the power supply network (3) and the electrical installation (4) upstream of the first AC-DC converter (5) and the second AC-DC converter (6), the vehicle (2) being connected to the charging station (1) via at least one DC connection (11).