Parallel Power Supply Units Current Balancing via Digital Feedback
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Solution Overview
Problem
Existing power supply units connected in parallel often experience uneven loading, leading to reduced service life due to performance limitations, as structurally identical units can differ slightly in output voltage, causing one unit to handle the full load while others contribute minimally.
Innovation Solution
Implementing a digital communication interface and bus interface within each power supply unit to compare and adjust output currents, allowing units to dynamically adjust their output voltage to achieve even current distribution without external complex wiring, using a CAN specification for communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If power supply units are connected in parallel without additional control measures, then the system can provide redundant capacity and handle higher loads, but the loading becomes uneven causing one unit to operate at maximum current continuously which reduces service life
Solution Approach 1:
The patent implements a feedback mechanism where each power supply unit measures its own output current and communicates this information to other units via a digital communication interface. Based on this feedback, each unit dynamically adjusts its output voltage to achieve balanced current distribution. The control unit compares measured current with target current and modifies the output voltage accordingly, creating a closed-loop control system that continuously optimizes load sharing.
Solution Approach 2:
The patent changes the operating parameters of each power supply unit dynamically based on real-time conditions. Specifically, the output voltage of each unit is adjusted as a control parameter to achieve equal current distribution. The control unit modifies voltage parameters based on measured current values and communication with other units, transforming the static parallel connection into a dynamically balanced system where parameters adapt to maintain optimal operation.
2Duration of action of stationary object
If additional external control loops are implemented to achieve even loading, then load distribution improves, but material costs and installation effort increase
Solution Approach 1:
The patent enables each power supply unit to autonomously determine its own operating parameters based on information exchanged with other units. Each unit measures its own current, communicates this data digitally, and independently adjusts its voltage without requiring external control signals. This self-service approach eliminates the need for complex external control loops while achieving balanced load distribution through decentralized autonomous control.
Solution Approach 2:
The patent replaces analog control circuits and external control loops with a digital communication-based control system. Instead of using complex analog voltage control circuits that require precise hardware adjustments, the system uses digital communication interfaces to exchange current information and implement control algorithms, substituting mechanical/electrical control complexity with digital information processing.
3Device complexity
If power supply units operate without current measurement and regulation, then the system is simpler, but one unit takes over full load causing uneven distribution and reduced reliability
Solution Approach 1:
The patent implements a control mechanism where each power supply unit measures its current and compares it with a target current value. When the measured current exceeds or falls short of the target, the unit adjusts its output voltage to correct the deviation. This partial adjustment approach, where only the necessary voltage modification is applied based on current measurements, achieves reliable load balancing without requiring overly complex control systems.
Data Source
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AI summary
The invention relates to a method for parallel connection of at least two power supply units (10a - 10c) on the output side, comprising the following steps: - Detecting in each case an output current (I) of the at least two power supply units (10a - 10c); - Transferring the detected output current values via a communication interface (16, 123) of the power supply units (10a - 10c); - Comparing the detected output current values; - Modifying at least one output voltage (U) of at least one of the power supply units (10a - 10c), depending on a result of the comparison of the detected output current values, if the comparison indicates an unequal load of the power supply units (10a - 10c). The invention further relates to a power supply unit (10a - 10c) geared to implementation of the method.