Multi-Phase Power Conversion Using Delayed Master PWM Signals
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Solution Overview
Problem
Existing multi-phase power conversion systems are complex and prone to oscillations in output inductor currents, leading to thermal performance issues and system malfunctions, due to the presence of multiple PWM comparators and interconnections between controllers and power converters.
Innovation Solution
A control system that uses a single PWM comparator to generate a master PWM signal, which is delayed and distributed to multiple power converters, allowing each to adjust the pulse width based on a delay lock loop signal for current balance, thereby simplifying the system and reducing interconnections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple PWM comparators are used in each power converter to independently control output voltage and current balance, then control precision is improved, but device complexity increases and oscillations occur
Solution Approach 1:
The patent merges multiple PWM comparators into a single centralized PWM comparator that generates master PWM signals for all power converters. This consolidation eliminates the complexity of having multiple independent comparators while maintaining control precision through centralized voltage feedback and current balance control mechanisms.
Solution Approach 2:
The single PWM comparator performs multiple functions: it generates master PWM signals for voltage regulation, provides timing references for phase-shift control, and enables current balance across all power converters through centralized control logic, replacing the need for dedicated comparators in each converter.
2Adaptability or versatility
If multiple PWM comparators and interconnections are used for adaptive control, then adaptability is improved, but system stability deteriorates due to oscillations
Solution Approach 1:
The patent implements centralized feedback control where the single PWM comparator receives voltage feedback from the output and current feedback from all power converters. This unified feedback mechanism ensures stable adaptive control by coordinating all power converters through a common control point, eliminating the oscillations caused by multiple independent feedback loops.
Solution Approach 2:
The single PWM comparator acts as an intermediary that mediates between the voltage feedback signal and the control signals for all power converters. It coordinates the operation of multiple converters through centralized timing and control logic, preventing the instability and oscillations that arise from direct interconnections between multiple controllers.
3Measurement precision
If each power converter has independent control circuits with multiple PWM comparators, then control precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent combines multiple PWM comparators that would traditionally be manufactured separately in each power converter into a single integrated control circuit. This merger reduces the total number of components, simplifies the manufacturing process, and lowers production costs while maintaining control precision through centralized control architecture.
Data Source
AI summary
A controller for controlling a multi-phase power conversion system includes a pulse width modulation (PWM) comparator configured to generate a PWM signal based on a ramp signal, a voltage reference signal and a feedback voltage from the power conversion system. A circuit may be configured to generate, based on the PWM signal, PWM signals by delaying the PWM signal with different delay times, and feed the PWM signals to respective switching power converters of the multi-phase power conversion system, to regulate an output voltage of the power conversion system. Each switching power converter may include a control circuit configured to adjust a pulse width of a received PWM signal based on a reference current and an output current of a corresponding switching power converter, to generate an adjusted PWM signal, based on which, an output voltage of the corresponding switching power converter is regulated.