Multi-Phase Bidirectional DC/DC Converter Phase Synchronization
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Solution Overview
Problem
Existing bidirectional DC/DC converters in hybrid electric and electric vehicles face inefficiencies in power transfer between 48 V and 12 V batteries, particularly in managing multiple phases and optimizing workload distribution, which affects the converter's endurance and reliability.
Innovation Solution
A multi-phase bidirectional DC/DC converter with autonomous phase circuits and dynamic programmable phase management, where each phase circuit determines its phase shift and operation based on a shared clock signal and unique identifier, allowing for synchronized operation and optimal power transfer in both buck and boost modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple phase circuits are used in bidirectional DC/DC converter, then power transfer capability and reliability are improved, but device complexity and difficulty of synchronization increase
Solution Approach 1:
The converter is divided into multiple independent phase circuits (first phase circuit, second phase circuit, etc.), each capable of autonomous operation. Each phase circuit includes its own bidirectional output stage, controller, and synchronization circuit, allowing the system to achieve higher reliability through modular architecture while managing complexity through standardization of phase units.
Solution Approach 2:
Multiple phase circuits are merged into a single integrated converter system that shares common components such as the 48V battery connection, 12V battery connection, and clock signal generation. The controllers of different phase circuits are synchronized through a shared clock signal, reducing overall system complexity while maintaining the benefits of multiple phases.
2Productivity
If dynamic phase management is implemented, then converter efficiency and power transfer optimization are improved, but control system complexity increases
Solution Approach 1:
The converter implements dynamic phase management where the number of active phases can be adjusted in real-time based on operating conditions. The controller can dynamically enable or disable specific phase circuits (e.g., activating only one phase during light load conditions, or activating multiple phases during high power transfer demands), optimizing efficiency while adapting to changing system requirements.
Solution Approach 2:
The system changes operational parameters by adjusting the number of active phases and the phase shift angles between different phase circuits. The controller modifies these parameters dynamically based on load conditions, battery states, and power transfer requirements, allowing the converter to operate at optimal efficiency points across different operating scenarios.
3Stability of the object's composition
If synchronized operation of multiple phase circuits is achieved, then workload distribution and ripple reduction are improved, but timing control complexity increases
Solution Approach 1:
The phase circuits operate with periodic switching cycles synchronized to a common clock signal. Each phase circuit switches at regular intervals with specific phase shifts relative to other phases (e.g., 180 degrees apart for two-phase operation), creating a periodic pattern that distributes workload evenly and reduces output ripple through constructive interference of current waveforms.
Solution Approach 2:
A common clock signal serves as an intermediary that coordinates the timing of all phase circuits. The clock signal is distributed to each phase circuit's controller, which uses it to generate synchronized switching commands. This intermediary timing mechanism simplifies coordination compared to direct inter-circuit communication, reducing control complexity while achieving stable synchronized operation.
Data Source
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AI summary
In an embodiment, a phase circuit (300) includes: a bidirectional output stage (321) configured to be coupled between a first battery (104) and a second battery (106); a memory (310) configured to store a number of active phases, and an identifier; and a synchronization circuit (306) configured to receive a first clock signal (SPWM_CLK) and determine a start time of a switching cycle of the bidirectional output stage based on the number of active phases, the identifier, and the first clock signal (SPWM_CLK), where the phase circuit is configured to control the timing of the switching of the bidirectional output stage based on the start time.