Isolated DC-DC Converter Control for Motor Drive EMI Compliance
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Solution Overview
Problem
Existing DC-DC converters in motor drive applications face challenges in achieving electromagnetic compatibility (EMC) compliance while maintaining target output voltages, particularly in systems with multiple isolated input and output voltages, and current methods struggle to adjust EMI emission spectra without hardware modifications.
Innovation Solution
A system utilizing a pulse width modulation controller and a programmable device to control multiple isolated power supplies, where the programmable device is powered by one output voltage and generates drive signals to regulate the other, enabling precise control over EMI emission spectra and voltage regulation through closed-loop feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If switching frequency is adjusted to achieve EMC compliance, then EMI emission is reduced, but output voltage regulation becomes more difficult to maintain
Solution Approach 1:
The patent implements dynamic adjustment of switching frequency through a programmable device that can modify the operating frequency of DC-DC converters in real-time. This allows the system to adapt the switching frequency to reduce EMI emissions while maintaining proper voltage regulation through closed-loop control, resolving the contradiction between EMI reduction and voltage regulation stability.
Solution Approach 2:
The system changes the switching frequency parameter dynamically based on EMI requirements. The programmable device monitors EMI levels and adjusts the switching frequency parameter accordingly, allowing the converter to operate at different frequencies to minimize electromagnetic emissions while maintaining output voltage within specification through feedback control.
2Object-affected harmful factors
If hardware is modified to control EMI emission spectrum, then EMI compliance is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces physical hardware modifications with a software-based solution using a programmable device. Instead of modifying the physical circuitry to control EMI, the system uses programmable logic to dynamically adjust switching parameters and frequency, achieving EMI spectrum control through software configuration rather than hardware changes, thereby reducing device complexity and manufacturing cost.
Solution Approach 2:
The system transitions from static hardware-based EMI filtering to dynamic software-controlled frequency adjustment. The programmable device enables real-time modification of switching characteristics without any physical hardware changes, allowing flexible EMI management through code updates rather than hardware redesign.
3Adaptability or versatility
If multiple isolated power supplies are used in motor drive electronics, then system functionality is improved, but EMI compliance becomes more difficult to achieve
Solution Approach 1:
The patent merges the control of multiple isolated power supplies under a single programmable device. This centralized control allows coordinated adjustment of switching frequencies and parameters across all converters, enabling EMI compliance to be achieved by managing the collective electromagnetic emissions of multiple supplies rather than treating each independently, thus maintaining system functionality while improving EMC performance.
Data Source
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AI summary
A system includes a pulse width modulation controller configured to control a first output voltage of a first power supply (127) associated with the system. The first power supply is referenced to a first input ground associated with the system and the first output voltage is referenced to a first output ground associated with the system. The system includes a programmable device (110) configured to configured to control a second output voltage of a second power supply (130) associated with the system. The second power supply is referenced to a second output ground associated with the system. The programmable device is powered based on the first output voltage.