DC Power Supply System with Reverse Charging Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing DC power supply systems with secondary batteries as backup power sources face inefficiencies in charging when the voltage of the DC power supply is lower than the secondary battery voltage, leading to reduced charging efficiency and increased energy loss due to the need for voltage stepping up using DC/DC converters.
Innovation Solution
The system incorporates a backup power supply circuit with dual DC/DC converters and a control circuit that dynamically switches between charging and discharging modes, using the secondary battery's power to add extra voltage to the DC power supply when it's lower, allowing direct current usage for charging, thereby maintaining high efficiency without relying on step-up converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a step-up DC/DC converter is used to charge the secondary battery when the DC power supply voltage is lower than the battery voltage, then charging is enabled, but the charging efficiency is reduced and energy loss increases
Solution Approach 1:
Instead of stepping up the DC power supply voltage to charge the battery, the invention inverts the approach by stepping down the battery voltage to match the DC power supply voltage, enabling direct charging without a step-up converter. This is achieved by configuring the DC/DC converter to operate in reverse mode, where the battery terminal becomes the input and the DC power supply terminal becomes the output, thereby eliminating the inefficiencies of high-ratio voltage stepping up.
Solution Approach 2:
The invention dynamically switches the operating mode of the DC/DC converter based on the voltage relationship between the DC power supply and the secondary battery. When the DC power supply voltage is higher than the battery voltage, the converter operates in normal charging mode. When the DC power supply voltage is lower, the converter switches to reverse mode to step down the battery voltage, thereby adapting to varying voltage conditions and maintaining high charging efficiency.
2Ease of operation
If the voltage of the DC power supply is lower than the voltage of the secondary battery, then direct charging is not possible, but using a step-up converter reduces charging efficiency
Solution Approach 1:
The invention resolves the contradiction by inverting the voltage conversion direction. Instead of attempting to step up the low DC power supply voltage to match the battery voltage, the system steps down the battery voltage to match the DC power supply voltage, enabling direct charging while maintaining high efficiency. This is accomplished by reversing the power flow direction through the DC/DC converter.
Solution Approach 2:
The invention changes the operating parameters of the DC/DC converter dynamically. When the DC power supply voltage is lower than the battery voltage, the converter operates in reverse mode with inverted voltage and current directions, effectively changing the conversion ratio from greater than 1 (step-up) to less than 1 (step-down), thereby maintaining high charging efficiency while enabling direct charging.
3Power
If a DC/DC converter is used to step up voltage for charging, then charging is enabled, but the current value decreases considerably
Solution Approach 1:
The invention inverts the voltage conversion approach to prevent current reduction. By stepping down the battery voltage to match the DC power supply voltage instead of stepping up, the system avoids the current multiplication effect that occurs in step-up converters. This maintains a higher charging current value while still enabling charging when the DC power supply voltage is lower than the battery voltage.
Solution Approach 2:
The system dynamically adjusts the DC/DC converter operation to maintain optimal charging current. When the DC power supply voltage is lower than the battery voltage, the converter switches to reverse mode, dynamically changing the current transfer ratio to prevent excessive current reduction, thereby maintaining higher charging power and productivity throughout the charging process.
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
This approach ensures high charging efficiency and effective power storage from DC power supplies like photovoltaic generators, even when the voltage is lower, by utilizing the secondary battery's power to enhance the input voltage, reducing energy loss and maintaining high discharging efficiency.
Implementation Method 1
a second charging DC/DC converter configured to add an extra voltage to a voltage of the DC power supply by using an electric power of the secondary battery
Data Source
AI summary
A DC power supply system includes a DC power supply and a secondary battery for backing up the DC power supply. When a voltage of the DC power supply is lower than a voltage of the secondary battery, the DC power system adds an extra voltage to the voltage of the DC power supply to provide an input voltage to the secondary battery higher than the voltage of the secondary battery by using an electric power of the secondary battery, and the secondary battery is charged.