Power Supply Controller Delay Adjustment for Boost Chopper Switching Loss
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Solution Overview
Problem
Conventional boost choppers experience increased switching loss due to changes in input voltage, which affects the timing at which the element voltage of a switching element becomes local minimum, leading to inefficiencies in power supply control.
Innovation Solution
A power supply controller that includes a detection unit for monitoring the inductor voltage, a delay adjustment unit that adjusts the delay time based on the inductor voltage, and a switch control unit that turns on the switching element at a timing when the inductor current becomes zero and the source-drain voltage is local minimum, thereby reducing switching loss and improving energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed delay time is set in advance for turning on the switching element, then the circuit structure is simple and easy to control, but switching loss increases when input voltage changes because the timing at which element voltage becomes local minimum shifts
Solution Approach 1:
The patent applies dynamics by making the delay time adjustable rather than fixed. The delay adjustment unit dynamically changes the delay time based on the detected inductor voltage, allowing the turn-on timing of the switching element to adapt to different input voltage conditions and maintain optimal switching loss while keeping the overall control structure relatively simple.
Solution Approach 2:
The patent changes the parameter of delay time based on the detected inductor voltage. When the inductor voltage indicates a particular operating condition, the delay adjustment unit modifies the delay time parameter to ensure the switching element turns on at the optimal moment, thereby reducing switching loss under varying input voltage conditions.
2Loss of energy
If the delay time is adjusted based on inductor voltage to reduce switching loss, then energy efficiency improves, but the device complexity increases due to additional detection and adjustment circuits
Solution Approach 1:
The patent applies self-service by using the existing inductor voltage signal for the delay adjustment. The detection unit utilizes the inductor voltage that is already present in the circuit, and the delay adjustment unit processes this existing signal to generate the appropriate delay time, thereby reducing switching loss without requiring extensive additional external components or complex control mechanisms.
Solution Approach 2:
The inductor voltage serves multiple functions: it is used for detecting the operating condition and simultaneously serves as the basis for adjusting the delay time. This multi-functionality reduces the need for separate sensing circuits and simplifies the overall control structure while achieving the goal of reducing switching loss.
3Loss of energy
If the switching element is turned on when inductor current becomes zero and source-drain voltage is local minimum, then switching loss is reduced, but precise timing control becomes more difficult
Solution Approach 1:
The patent applies feedback by using the detection unit to monitor the inductor voltage and feed this information back to the delay adjustment unit. This feedback mechanism enables precise timing control for turning on the switching element at the optimal moment (when inductor current is zero and source-drain voltage is at local minimum) while maintaining ease of operation through automatic adjustment rather than manual calibration.
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 reduces switching loss and improves energy efficiency by aligning the turn-on timing of the switching element with the zero inductor current and local minimum source-drain voltage, even with changes in input voltage, thus enhancing the power supply's performance.
Implementation Method 1
The boost chopper may include a boost transformer having a main winding functioning as the inductor and an auxiliary winding. The detection unit may use an auxiliary winding voltage as the first value.
Data Source
AI summary
When an input voltage changes due to switching of an AC power supply, as a result of a change in a timing at which an inductor current becomes zero and an element voltage of a switching element becomes local minimum, a switching loss increases. Provided is a power supply controller that includes a switch control unit that controls an on/off of a switching element of a boost chopper; a detection unit that detects that a first value based on an inductor voltage of an inductor of the boost chopper is less than a threshold: and a delay adjustment unit that adjusts a delay time from when the detection unit detects that the first value is less than the threshold until when the switch control unit turns on the switching element according to a second value based on the inductor voltage.