Switching Controller for Hybrid Fuel Cell Battery Power Management
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Solution Overview
Problem
Existing hybrid fuel cell/battery systems face challenges in efficiently managing power distribution between fuel cell stacks and batteries, leading to high energy losses and potential degradation of the fuel cell stack due to frequent switching, and require expensive bi-directional DC-DC converters for effective power sharing.
Innovation Solution
A switching controller that sets the proportion of a switching period for connecting voltage sources to a load based on received characteristics, such as stack voltage, current, temperature, and pressure, using a single DC-DC converter and field effect transistor switches, allowing for reduced energy losses and efficient power sharing through 'battery blending' and 'active charging' strategies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If bi-directional DC-DC converters are used for power sharing between fuel cell stack and battery, then power distribution efficiency is improved, but system cost and complexity increase
Solution Approach 1:
The patent introduces a switching controller as an intermediary device that manages power sharing between the fuel cell stack and battery without requiring complex bi-directional DC-DC converters. The controller uses switching elements to connect different voltage sources to the load, simplifying the system architecture while maintaining effective power distribution control
Solution Approach 2:
The patent changes the control parameter from continuous power regulation (requiring complex converters) to discrete switching control. By controlling the duty cycle of switching elements, the system achieves power sharing through temporal modulation rather than continuous analog control, reducing system complexity
2Adaptability or versatility
If frequent switching between voltage sources is performed, then power flexibility is improved, but energy losses and fuel cell degradation increase
Solution Approach 1:
The patent implements periodic switching control where the switching controller operates in fixed cycles, connecting different voltage sources to the load in a structured periodic manner. This reduces unnecessary frequent switching while maintaining power flexibility through controlled duty cycle adjustment
Solution Approach 2:
The switching controller uses feedback from voltage source characteristics (such as battery state of charge, fuel cell output voltage) to intelligently determine switching timing and duration. This feedback mechanism optimizes switching frequency to minimize energy losses and fuel cell degradation while preserving power flexibility
3Speed
If switching frequency is increased, then response speed is improved, but energy losses due to switching increase
Solution Approach 1:
The patent implements dynamic switching frequency control where the switching frequency is adjusted based on system conditions. The switching controller can operate at lower frequencies during steady-state conditions to minimize losses, and increase frequency only when rapid response is genuinely required, optimizing the trade-off between response speed and energy efficiency
Data Source
AI summary
A switching controller for coupling one of a plurality of voltage sources to a load. The switching controller is configured to receive a characteristic of one of the plurality of voltage sources; for each of the plurality of voltage sources, set a proportion of a switching period of a control signal during which the voltage source is connected to the load, wherein the proportion of the switching period is set based on the received characteristic of one of the plurality of voltage sources; and control which of the plurality of voltage sources is connected to the load in accordance with the control signal.