Bypass Circuit for Multi-Stage DC-DC Converters
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Solution Overview
Problem
Existing multi-stage DC-DC converters for battery-powered systems suffer from low efficiency due to the unnecessary operation of flyback converters, which are required for vehicle power but not needed for battery power, leading to reduced battery life and increased power consumption.
Innovation Solution
A high efficiency bypass circuit that uses a single control signal to connect the output of the boost converter directly to the output terminal, disabling the flyback converter and adjusting the output voltage to match the flyback converter's output, thereby bypassing the inefficient flyback converter stage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a flyback converter is used in multi-stage DC-DC converters for battery-powered systems, then the system can manage wide input voltage ranges and provide DC isolation, but the efficiency is reduced to approximately 70% and battery life is shortened
Solution Approach 1:
The system dynamically switches between two operational modes: a two-stage mode (boost converter + flyback converter) for wide input voltage ranges, and a single-stage bypass mode (boost converter only) for narrow input voltage ranges. The relay control circuit enables this dynamic reconfiguration, connecting the boost converter output directly to the output terminal when the flyback converter is bypassed, thereby optimizing efficiency for battery-powered applications while maintaining adaptability for vehicle power applications.
Solution Approach 2:
The invention extracts and removes the flyback converter stage from the power conversion chain when it is not needed for battery-powered systems. By using a relay to bypass the flyback converter and connect the boost converter output directly to the output terminal, the system eliminates the unnecessary energy loss associated with the flyback converter while retaining the capability to include it when wide input voltage management is required.
2Reliability
If a two-stage DC-DC converter with flyback converter is used, then DC isolation between vehicular source and load is provided, but power consumption increases and battery life is reduced
Solution Approach 1:
The system dynamically adjusts its architecture based on the power source being used. When battery power is detected, the relay bypasses the flyback converter, eliminating unnecessary power consumption while maintaining adequate DC isolation through the boost converter alone. When vehicle power is used, the flyback converter is activated to provide enhanced DC isolation. This dynamic reconfiguration optimizes power consumption for battery-powered applications while maintaining reliability requirements.
Solution Approach 2:
The invention removes the flyback converter from the active power conversion path when battery power is detected, thereby eliminating the additional power consumption and heat generation associated with this stage. The relay control circuit enables this extraction by routing power directly from the boost converter to the output terminal, reducing overall system power consumption while maintaining necessary isolation functions through the remaining boost converter stage.
3Measurement precision
If the flyback converter operates in battery-powered systems, then the system maintains consistent output voltage regulation, but efficiency is reduced and heat generation increases
Solution Approach 1:
The control circuit dynamically adjusts the operational configuration based on the detected power source. When battery power is detected, the system switches to a single-stage mode where the relay connects the boost converter output directly to the output terminal, eliminating the flyback converter stage. This dynamic reconfiguration maintains precise output voltage regulation through the boost converter alone while eliminating the additional heat generation that would occur in the flyback converter stage.
Solution Approach 2:
The invention extracts the flyback converter stage from the power conversion chain in battery-powered applications, removing the source of additional heat generation and energy loss. The relay control circuit enables this extraction by bypassing the flyback converter and directly connecting the boost converter output to the output terminal, thereby maintaining voltage regulation precision while eliminating unnecessary heat generation.
Data Source
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AI summary
A system and method are disclosed for providing a high efficiency bypass circuit for multi-stage direct current to direct current (DC-DC) converters used in battery powered systems. When the system is operating in a battery mode, the vehicle power source is unplugged from the power supply input connector and the external battery is connected in its place. The system uses a relay to bypass the flyback converter so as to connect the boost converter output directly to the output terminals. The system uses a single control signal to: 1) energize the relay connecting the boost converter output directly to the output terminals, 2) adjust the boost converter circuit to cause the boost converter to deliver a voltage equal to what the flyback converter would have delivered, and 3) disable the flyback converter.