Power Conversion Device Driving Resistor Circuit Control
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Solution Overview
Problem
Power conversion devices face challenges in controlling power transistor switching loss, surge voltage, and electromagnetic interference due to increased conduction time and conducting speed, which affect efficiency and reliability.
Innovation Solution
A power conversion device and control method that includes a primary side rectifier, main converter, secondary side rectifier, feedback controller, PWM controller, and driving compensator, where the resistance value of the driving resistor circuit is adjusted based on the input voltage to control the driving current and conduction time of the power transistor, thereby optimizing efficiency and reducing electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the driving resistance of the power transistor is lowered and driving current is increased to reduce switching loss, then the switching speed is improved and conversion efficiency is elevated, but the surge voltage increases significantly and electromagnetic interference increases
Solution Approach 1:
The patent applies dynamics by making the driving resistance adjustable rather than fixed. The driving resistance is dynamically changed based on the input voltage level: at low input voltage, lower resistance is used to increase driving current and reduce switching loss; at high input voltage, higher resistance is used to limit driving current and reduce surge voltage and electromagnetic interference. This dynamic adjustment resolves the contradiction between reducing switching loss and preventing electromagnetic interference.
Solution Approach 2:
The patent changes the parameter of driving resistance based on operating conditions (input voltage level). By switching between different resistance values according to the input voltage, the system optimizes the driving current to simultaneously achieve low switching loss and controlled surge voltage, thereby resolving the contradiction between energy efficiency and electromagnetic interference reduction.
2Productivity
If the power transistor conducting speed is increased to reduce switching loss, then the conversion efficiency is improved, but the surge voltage exceeds the rated voltage and electromagnetic interference increases
Solution Approach 1:
The patent uses dynamic adjustment of driving resistance to control the power transistor conducting speed. At low input voltage, higher driving current enables faster conduction and improves conversion efficiency. At high input voltage, reduced driving current slows down the conduction speed to prevent surge voltage from exceeding rated voltage, thereby maintaining reliability. This dynamic control resolves the contradiction between productivity and reliability.
Solution Approach 2:
The patent changes the driving resistance parameter according to input voltage conditions to control the conducting speed of the power transistor. This parameter adjustment ensures that the power transistor operates at optimal speed for efficiency while preventing excessive surge voltage that would compromise reliability, thus resolving the contradiction between conversion efficiency and surge voltage control.
3Loss of energy
If the driving current is increased to reduce switching loss, then the conduction time is shortened and efficiency is improved, but the surge voltage increases and electromagnetic interference increases
Solution Approach 1:
The patent applies dynamics by making the driving current adjustable through variable driving resistance. At low input voltage, higher driving current is permitted to reduce switching loss and shorten conduction time. At high input voltage, the driving current is automatically reduced to prevent excessive surge voltage generation. This dynamic current control resolves the contradiction between reducing energy loss and preventing harmful surge voltage.
Solution Approach 2:
The patent changes the driving current parameter based on input voltage conditions by adjusting the driving resistance. This parameter modification allows the system to achieve low switching loss through higher current at appropriate times while preventing surge voltage generation by reducing current when input voltage is high, thereby resolving the contradiction between energy efficiency and harmful factor reduction.
Data Source
AI summary
A power conversion device includes a primary side rectifier, a main converter, a secondary side rectifier, a secondary side feedback controller, a PWM controller, and a driving compensator. The primary side rectifier is configured to generate a first voltage. The main converter includes a power transistor and is configured to adjust the first voltage to generate a second voltage according to a control signal. The secondary side rectifier is configured to generate an output voltage according to the second voltage. The secondary side feedback controller is configured to generate a feedback signal according to the output voltage. The PWM controller is configured to generate a PWM signal according to the feedback signal. The driving compensator includes a driving resistor circuit. The PWM signal outputs the control signal through the driving resistor circuit, and the driving compensator adjusts a resistance value of the driving resistor circuit according to the first voltage.