Dynamic Power Distribution for EV Battery Charging
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Solution Overview
Problem
Existing battery charging systems face issues when charging in-vehicle batteries in electric vehicles, as the voltage of the battery can exceed its upper limit due to surplus power from PWM pulse-driven air conditioners, leading to potential battery deterioration.
Innovation Solution
A battery charging system that dynamically adjusts the power distribution between battery charging and load operation by using a system control unit to set the supply power based on the state of charge (SOC) of the battery and the request driving power, ensuring the charging power does not exceed the allowable limit, thereby preventing voltage exceeding the upper limit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If power is supplied to the battery preferentially during charging operation, then the battery charging efficiency is improved, but the battery voltage may exceed the upper limit when the air conditioner power consumption decreases periodically
Solution Approach 1:
The patent applies dynamics by making the supply power from the external power source dynamically adjustable based on real-time conditions. The system continuously monitors the air conditioner's power consumption and battery state, then adjusts the supply power accordingly. This is achieved through the controlling section that sets the supply power to a predetermined value during air conditioner operation, preventing voltage excursions while maintaining charging efficiency.
Solution Approach 2:
The patent implements feedback mechanisms where the system continuously monitors the air conditioner's power consumption and battery voltage levels. When the air conditioner power consumption decreases below a threshold, the system detects this change and adjusts the supply power from the external power source to prevent battery voltage from exceeding the upper limit. This closed-loop control ensures both charging efficiency and voltage stability.
2Reliability
If the charging current is temporarily decreased at the start of air conditioner drive, then the spike current is accommodated, but the battery voltage may still exceed the upper limit due to subsequent power distribution
Solution Approach 1:
The patent applies preliminary action by setting the supply power from the external power source to a predetermined limited value before and during air conditioner operation. Rather than temporarily adjusting current and risking subsequent voltage excursions, the system proactively limits the supply power to a safe level that accounts for the air conditioner's minimum power consumption. This prevents both spike current issues and subsequent voltage excursions, maintaining safe battery voltage throughout the operation.
Data Source
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AI summary
A battery charging system includes a battery, a load and a controller to control supply power to be supplied from an external power source to the battery and the load, in accordance with a request charging power and a request load power. The controller limits power supplied from the external power source to the battery to an allowable battery power, and distributes the supply power from the external power source between the battery and the load in a state holding limitation of limiting the supply power from the external power source to the allowable battery power when a request for the supply of power to the load is generated.