Power Conditioner Duty-Cycle Control for Voltage Transitions
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Solution Overview
Problem
Power conditioners, such as DC-DC converters, face challenges in maintaining stable output voltage levels when switching between different supply sources, leading to potential overshoot or undershoot, which can disrupt or damage connected loads.
Innovation Solution
A method and system that monitor voltage levels from multiple supply sources and control the duty-cycle of the output switch using feedback-based control signals, with an estimated control signal generated by multiplying previous feedback-based control signals by the ratio of the first to the second voltage level during a supply source change, to mitigate overshoot or undershoot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a backup supply source is rapidly swapped into service to ensure continuous power supply, then the reliability of power supply is improved, but the output voltage level stability deteriorates due to step change in input voltage level causing overshoot or undershoot
Solution Approach 1:
The controller predicts the required duty cycle adjustment before the supply source swap is completed by calculating the ratio between the old and new input voltage levels. This preliminary action allows the control signal to be prepared in advance, ensuring smooth transition and preventing output voltage overshoot or undershoot when the backup supply source is rapidly swapped into service.
Solution Approach 2:
The system uses feedback control by monitoring the output voltage level and comparing it with a target voltage level. The controller adjusts the duty cycle of the output switch based on the error between the actual and target voltage levels, ensuring that the output voltage remains stable even during supply source transitions. This feedback mechanism continuously corrects any deviations caused by input voltage step changes.
2Stability of the object's composition
If feedback-based control signals are used to regulate output voltage level, then the output voltage stability is improved, but the response time during supply source changes deteriorates due to the sampling frequency limitation
Solution Approach 1:
The controller performs preliminary calculation of the duty cycle adjustment ratio based on the known input voltage levels before the supply source swap occurs. By predicting the required control signal adjustment in advance using the voltage ratio, the system overcomes the delay inherent in waiting for the next feedback sampling cycle, thus improving response time during supply source transitions while maintaining output voltage stability.
Data Source
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AI summary
A method for regulating a power conditioner output voltage level includes monitoring a first voltage level of a first supply source and a second voltage level of a second supply source and, while the power conditioner is being supplied by the first supply source, controlling a duty-cycle of an output switch of the power conditioner with feedback-based control signals generated based on errors between a target voltage level and samples of the output voltage level obtained at an output voltage sampling frequency. The method also includes, controlling, for a period corresponding to the output voltage sampling frequency, the duty-cycle of the output switch with an estimated control signal. The method also includes, while the power conditioner is being supplied by the second supply source, controlling the duty-cycle of the output switch using the feedback-based control signals.