Multi-Phase PWM Converter Transient Mode Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-phase power switching converters face challenges in maintaining well-controlled closed loop feedback dynamics during transient conditions, where the maximum allowable duty cycle is exceeded, especially when using time division multiplexers (TDM) that do not allow for effective transient response control.
Innovation Solution
A multi-phase power switching converter operates in two states: a first state with sequential coupling of driver inputs to a pulse width modulator (PWM) for duty cycles below the maximum, and a second state where all driver inputs are simultaneously coupled to the PWM when the duty cycle exceeds the maximum, utilizing a phase-mode selector and switch bank to manage the transition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If time division multiplexer (TDM) is used to sequentially switch drivers, then low duty cycle requirement is satisfied, but closed loop control during transient conditions deteriorates
Solution Approach 1:
The system dynamically switches between two operational modes: interleaved mode for normal operation and all-phase mode for transient conditions. The mode selection is based on real-time feedback from the error amplifier, allowing the system to adapt its control strategy to maintain reliability during transient loading conditions while satisfying low duty cycle requirements during normal operation.
Solution Approach 2:
The invention changes the operational parameter (duty cycle) by switching between two distinct modes. In interleaved mode, the duty cycle is limited to 100/N, while in all-phase mode, the duty cycle can exceed this limit. This parameter change allows the system to handle transient conditions that require higher duty cycles while maintaining low duty cycle operation during normal conditions.
2Adaptability or versatility
If all phase branches are hard-switched on during transient conditions, then duty cycle limit is exceeded, but transient response control deteriorates
Solution Approach 1:
The error amplifier continuously monitors the output voltage and provides feedback to the PWM controller. During transient conditions, this feedback mechanism ensures that even when all phase branches are activated, the system maintains adequate closed-loop control by adjusting the PWM duty cycle based on the error signal, preventing loss of control while exceeding the normal duty cycle limit.
Solution Approach 2:
The PWM controller is designed to perform multiple functions: it controls the interleaved mode for normal operation and simultaneously controls the all-phase mode for transient conditions. This multi-functionality allows the single PWM to manage both operational modes with appropriate control strategies, maintaining transient response control while expanding the duty cycle range.
3Ease of operation
If interleaved mode is used for normal operation, then low duty cycle is maintained, but transient handling capability is limited
Solution Approach 1:
The system employs dynamic mode switching between interleaved and all-phase operations based on transient detection. The error amplifier detects transient conditions and triggers a switch from interleaved mode to all-phase mode, allowing the system to maintain low duty cycle operation during normal conditions while gaining enhanced transient handling capability when needed.
Solution Approach 2:
The system prepares for transient conditions by having the all-phase mode capability pre-configured and ready to activate. The error amplifier continuously monitors for transient conditions, and when detected, the system immediately switches to the pre-prepared all-phase mode, ensuring smooth transition and adequate transient handling without loss of control.
Data Source
AI summary
A multi-phase power switching converter having first and second states includes a pulse width modulator having an output, a converter output providing an output signal, and a plurality of drivers, each having an output electrically coupled to the converter output and an input. When the converter is in the first state where a duty cycle of the converter is less than or equal to 100 divided by the number of drivers, each of the driver inputs is configured to be sequentially electrically coupled to the pulse width modulator output. When the converter is in the second state where the duty cycle of the converter is greater than 100 divided by the number of drivers, each of the driver inputs is simultaneously electrically coupled to the pulse width modulator output.