Parallel Power Supply Current Sharing for Fast Dynamic Loads
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Solution Overview
Problem
Existing power supply systems with parallel-connected units face challenges in achieving fast and accurate dynamic current sharing, particularly under severe and continuous dynamic load conditions, leading to uneven output currents and poor load response due to limitations in current-sharing technologies such as active and droop current-sharing methods.
Innovation Solution
The integration of active current-sharing control, average current difference compensation control, and droop current control within a power supply unit and system, utilizing a current detection circuit, detection signal peripheral circuit, and control processor to generate control signals that adjust output voltage and current, ensuring equal output currents across parallel-connected power supply units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If active current-sharing technology is used to achieve accurate current sharing under stable load, then current-sharing precision is improved, but dynamic load response speed deteriorates
Solution Approach 1:
The patent applies dynamics by making the current-sharing control method adaptable to different operating conditions. The system dynamically switches between active current-sharing control (for stable loads) and droop current-sharing control (for dynamic loads), allowing the control strategy to change based on real-time load conditions. This resolves the contradiction by enabling the system to optimize for precision when loads are stable and for speed when loads change dynamically.
Solution Approach 2:
The patent changes the control parameter from a fixed active current-sharing method to a variable method that selects between active and droop control based on load characteristics. By monitoring load current changes and switching control modes accordingly, the system adjusts its behavior to maintain both precision and speed under different operating conditions.
2Speed
If droop current-sharing technology is used to achieve fast dynamic load response, then response speed is improved, but current-sharing accuracy deteriorates
Solution Approach 1:
The system dynamically selects the appropriate control mode based on real-time load conditions. When dynamic load changes are detected, droop current-sharing control is activated for fast response. When loads are stable, the system switches to active current-sharing control for high precision. This dynamic adaptation resolves the contradiction between speed and accuracy.
Solution Approach 2:
The patent applies droop current-sharing control partially - only when dynamic load conditions are detected. For the majority of stable operating conditions, active current-sharing control is used. This partial application of droop control provides fast response when needed without sacrificing overall current-sharing accuracy during stable operation.
3Power
If parallel-connected power supply units are used to handle high power loads, then power capacity is improved, but current-sharing performance under dynamic loads deteriorates
Solution Approach 1:
The patent implements feedback by continuously monitoring the load current and detecting dynamic load conditions. Based on this feedback, the system automatically switches between active and droop current-sharing control modes. This feedback mechanism ensures that parallel-connected power supply units maintain optimal current-sharing performance under both stable and dynamic load conditions, resolving the reliability issue while preserving power capacity.
Solution Approach 2:
The system makes the current-sharing control dynamic by adapting to real-time load conditions. When parallel power supply units operate under stable loads, active control ensures precise current sharing. When dynamic load changes occur, droop control provides fast response. This dynamic adaptation maintains reliable current-sharing performance across all operating conditions while preserving the power capacity benefits of parallel connection.
Data Source
AI summary
A power supply system with dynamic current sharing includes a current-sharing bus and a plurality of power supply units connected to each other through the current-sharing bus. The current-sharing bus provides a first current signal. Each power supply unit includes a local current bus for providing a second current signal. The active current-sharing unit compares the first current signal with the second current signal to generate a compensation voltage. The current-averaging unit compares a difference value between an average value of the first current signal and an average value of the second current signal to generate an average voltage. The droop current unit receives the second current signal to generate a droop compensation voltage. The integration calculation unit makes output currents of the power supply units be approximately equal according to the compensation voltage, the average voltage, and the droop compensation voltage.