DC-DC Converter Auxiliary Switch Duty Control by Load Power
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Solution Overview
Problem
Existing DC-DC converters face challenges in minimizing energy loss due to rapid load fluctuations, particularly in applications like electric vehicles, where controlling the duty of the auxiliary switch in real time is difficult, leading to increased freewheeling margins and energy inefficiency.
Innovation Solution
A load power based DC-DC converter that calculates load power through the output terminal and controls the auxiliary switch's duty based on this power, using a lookup table to adjust the duty according to predefined load power margins, thereby reducing freewheeling margins and energy loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the duty of the auxiliary switch is controlled in real-time to minimize energy loss, then power efficiency is improved, but device complexity increases due to the need for real-time load power calculation and dynamic control
Solution Approach 1:
The patent changes the control parameter from fixed duty cycle to dynamic duty cycle based on load power. The controller calculates load power in real-time and adjusts the auxiliary switch duty cycle accordingly, transforming the system from static parameter control to dynamic parameter adjustment, thereby reducing energy loss while maintaining manageable complexity through systematic control strategy
Solution Approach 2:
The patent implements feedback control by continuously monitoring the output voltage and current at the output terminal, calculating load power based on these measurements, and using this feedback information to adjust the auxiliary switch duty cycle. This closed-loop feedback mechanism enables real-time optimization of power efficiency while keeping control complexity organized through structured feedback processing
2Power
If the auxiliary switch duty is increased to handle higher load power, then power transfer capability is improved, but energy loss increases due to larger freewheeling margins
Solution Approach 1:
The patent applies dynamics by making the auxiliary switch duty cycle variable rather than fixed. The duty cycle dynamically adapts to load power conditions - increasing when load power is high to maintain power transfer capability, and decreasing when load power is low to minimize freewheeling margins and energy loss. This dynamic adjustment resolves the contradiction between power capability and energy efficiency
Solution Approach 2:
The patent changes the duty cycle parameter based on load power levels. By calculating load power and adjusting the auxiliary switch duty cycle accordingly, the system optimizes the balance between power transfer capability and energy loss - using higher duty cycles only when necessary for high power loads, and reducing duty cycles for low power conditions to minimize freewheeling losses
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 enhances power efficiency by minimizing energy loss and improving control responsiveness by adjusting the auxiliary switch duty based on real-time load power calculations, reducing the complexity of control.
Implementation Method 1
a resonant circuit that is connected to the input circuit and includes an auxiliary switch for zero-voltage switching the main switch
Data Source
AI summary
Proposed is a load power based DC-DC converter. The load power based DC-DC converter may include an input circuit that is connected to an input terminal and includes a main switch. The converter may also include a resonant circuit that is connected to the input circuit and includes an auxiliary switch for zero-voltage switching the main switch. The converter may further include an output circuit that is connected to the resonant circuit and outputs a voltage to an output terminal. The converter may further include a controller that controls the main switch and the auxiliary switch, in which the controller calculates a load power, which is power output through the output terminal, and controls the auxiliary switch so that on duty of the auxiliary switch increases or decreases based on the load power.