DC Power Supply Current Sharing via Distributed Bus Control
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Solution Overview
Problem
Existing digital current sharing methods for rectifier modules in parallel connection face challenges such as high communication traffic and the need for a master-slave configuration, which can lead to reliability issues and complexity.
Innovation Solution
A current sharing method and device that uses the latest detected bus current as a reference to control local host currents, calculating and timing the sending time based on a preset relationship, allowing any rectifier to send the bus current when the previous one fails, eliminating the need for a master machine and reducing communication traffic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the average current method is used for digital current sharing control, then current sharing precision is improved, but communication traffic increases significantly with the number of parallel connections
Solution Approach 1:
The patent extracts only the essential current sharing information from each rectifier module and transmits it sequentially through the communication bus. Instead of all rectifiers simultaneously exchanging current data (which generates N/2 communication traffic), only one rectifier's current data is transmitted at a time in a round-robin fashion, dramatically reducing communication traffic while maintaining current sharing precision through timely data updates.
2Quantity of substance
If the master-slave method is used for digital current sharing control, then communication traffic is reduced, but system reliability decreases due to single point of failure
Solution Approach 1:
The patent assigns equal functional capabilities to all rectifier modules, with each module equipped with both master and slave functionality. Any rectifier can initiate current data transmission when its timing counter expires, eliminating the single point of failure associated with a dedicated master machine. This distributed architecture maintains low communication traffic while significantly improving system reliability through redundancy.
3Ease of operation
If a dedicated master machine is used for current sharing control, then control simplicity is achieved, but device complexity increases due to fault detection mechanisms
Solution Approach 1:
The patent implements a self-organizing distributed control mechanism where each rectifier module autonomously manages its own current data transmission timing. Each module uses a local timing counter that automatically expires and triggers data transmission without requiring centralized coordination or complex fault detection mechanisms. This self-service approach simplifies the overall control architecture while maintaining systematic current sharing.
Data Source
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AI summary
A current sharing method and device for a DC power supply are provided, and the method includes: taking a latest detected bus current as a reference current to perform current sharing control on a local host current; calculating and timing sending time of the local host current according to the latest detected bus current, the local host current, and a preset corresponding relationship between a difference between the local host current and the bus current and the sending time of the local host current, and if no new bus current is detected within a timing time, sending the local host current as a new bus current to a bus when the timing times out.. The method has small communication traffic and no master-slave relationship, and is simple to control, which reduces the difficulty of system development and improves the system reliability.