Parallel DC Power Supply Load Sharing Without Control Lines
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Solution Overview
Problem
Existing DC power supply systems with multiple small-capacity units connected in parallel face challenges in coordinating control signals, leading to complex control lines and difficulty in achieving a smaller size and higher efficiency.
Innovation Solution
A DC power supply system where each unit operates in an inactive state if the supplied voltage is higher than its output voltage and switches to active states based on a predetermined output characteristic, transitioning between constant voltage and constant current modes to adapt to varying load currents without signal coordination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If multiple small-capacity DC power supply units are connected in parallel to achieve larger capacity, then the required power output increases, but the control system complexity increases due to coordination requirements
Solution Approach 1:
Each DC power supply unit autonomously determines its own operating state (active or inactive) by comparing its output voltage with the common output voltage, without requiring control signals from other units. This self-service mechanism eliminates the need for complex coordination control systems while achieving balanced load sharing among parallel units
Solution Approach 2:
The patent utilizes natural parameter variations (voltage differences) among parallel DC power supply units as the basis for automatic state switching. By changing the operating state based on voltage parameter comparison rather than control signals, the system achieves simple and reliable coordination without complex control circuitry
2Volume of moving object
If multiple small-capacity DC power supply units are connected in parallel to reduce size, then the equipment size decreases, but the control line quantity increases
Solution Approach 1:
The patent extracts the coordination control function from the control system and replaces it with autonomous voltage-based state determination at each unit. This eliminates the need for control lines connecting between power supply units, reducing control line quantity to zero while maintaining proper coordination
Solution Approach 2:
Each unit independently determines its activation state by comparing its own output voltage with the common output voltage, eliminating the need for inter-unit control signal transmission and reducing control line complexity
3Stability of the object's composition
If DC power supply units operate in parallel with coordination control, then the power distribution is balanced, but the control signal transmission requirements increase
Solution Approach 1:
Each DC power supply unit continuously monitors the common output voltage and uses this feedback to autonomously determine whether to remain active or switch to inactive state. This voltage feedback mechanism ensures balanced power distribution without requiring control signal transmission between units
Solution Approach 2:
Each unit autonomously adjusts its operating state based on voltage feedback, eliminating the need for external control signals and reducing information transmission requirements while maintaining balanced power distribution
Data Source
AI summary
A plurality of DC power supply apparatuses which are CVCC power supplies have output sides connected in parallel to a load. In each of the plurality of DC power supply apparatuses, an upper limit current maintained in a CC mode is designed to be equal to or lower than a rated current. Output voltages from the plurality of DC power supply apparatuses are actually different from equivalently set reference voltages Vr, due to variation within an allowable voltage range of the load 120. The plurality of DC power supply apparatuses operate to supply currents, as being accompanied by transition from a CV mode to the CC mode, sequentially in the descending order of magnitude of actual output voltages thereof, with increase in output current to the load.