DC/DC Power Supply Parallel Operation Control

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Solution Overview

Problem

Existing power supply systems with multiple converter units face challenges in parallel operation, including cumbersome adjustment processes, uneven load distribution, and potential premature system failure due to hard parallel switching, and require manual adjustment of output voltages, which is time-consuming and prone to errors.

Innovation Solution

A power supply system with a higher-level controller that includes a monitoring unit to automatically detect parallel connections and adjust setpoints, ensuring balanced voltage and current regulation across converter units without manual intervention, allowing for seamless load distribution and reliable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If hard parallel switching is used with manual adjustment of output voltages, then parallel connection of converter units is achieved, but the adjustment process becomes cumbersome and time-consuming

Engineering Contradiction:
Improveparallel operation capabilityVSAvoidadjustment time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system performs self-adjustment through automatic detection of parallel connections and autonomous modification of control parameters. The control circuit detects when converter units are connected in parallel and automatically adjusts output voltage setpoints and current limiting values without requiring manual intervention from operating personnel.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements feedback mechanisms where the control circuit continuously monitors output parameters and parallel connection status, then automatically adjusts control variables based on detected conditions. This closed-loop approach enables the system to adapt to parallel operation dynamically without manual reconfiguration.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If hard parallel switching is used with manual voltage adjustment, then converter units can operate in parallel, but load distribution becomes uneven causing premature failure

Engineering Contradiction:
Improveparallel operation capabilityVSAvoidsystem reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The control system autonomously detects parallel connections and automatically balances load distribution by adjusting individual converter unit parameters. This self-regulating mechanism prevents any single unit from bearing excessive load, thereby distributing stress evenly and preventing premature failure of individual components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system dynamically modifies control parameters such as output voltage setpoints and current limiting values based on the detected parallel operation status. By changing these parameters automatically, the system ensures optimal load sharing among converter units, preventing overload conditions that would lead to premature failure.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If output voltage differences occur due to setting accuracy limits and drift, then converter units can be connected in parallel, but one unit supplies entire load until current limit is reached

Engineering Contradiction:
Improveparallel connection capabilityVSAvoidload distribution balance
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The control circuit continuously monitors output voltages and current levels of parallel-connected converter units. When voltage differences or current limit conditions are detected, the system automatically adjusts the control parameters of individual units to restore balanced load distribution, ensuring smooth operation without manual intervention.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system transitions from static manual voltage setting to dynamic automatic parameter adjustment. The control circuit continuously adapts output voltage setpoints and current limiting values based on real-time operating conditions, enabling the converter units to automatically share load evenly despite initial voltage differences or drift.

Inventive Principle:
Principle #15Dynamics

4Stability of the object's composition

If soft characteristic curve is used to reduce output voltage with increasing current, then parallel operation stability is improved, but adjustment by operating personnel remains time-consuming

Engineering Contradiction:
Improveparallel operation stabilityVSAvoidadjustment time
Core Design Contradiction:
Stability of the object's compositionVSLoss of time

Solution Approach 1:

The system automatically configures and adjusts the soft characteristic curve parameters when parallel operation is detected, eliminating the need for manual adjustment by operating personnel. The control circuit autonomously modifies the voltage-current relationship to achieve stable parallel operation without requiring user intervention or time-consuming setup procedures.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2812969B1Dc/dc power supply with outputs that can be connected in parallel
Publication Date: 2020.02.26 SIEMENS AG
  • EP2812969B1 patent drawingFigure 1~2
  • EP2812969B1 patent drawingFigure 3~4
  • EP2812969B1 patent drawingFigure 5

AI summary

The invention relates to a power supply unit comprising at least a first and a second converter unit (W1, W2). The first converter unit (W1) is controlled by a first controller (S1) and supplies a first output voltage (U1) regulated by a first voltage regulator and/or an output current regulated by a first current regulator at a first output (OUT1). The second converter unit (W2) is controlled by a second controller (S2) and supplies a second output voltage (U2) that can be regulated by a second voltage regulator and/or an output current that can be regulated by a second current regulator at a second output (OUT2). The two outputs (OUT1, OUT2) can be connected in parallel to supply a higher output power. At least one controller (S1, S2, STR) comprises a monitoring unit for recognizing a parallel connection at the output end, a recognition signal which automatically switches the signal status thereof when the outputs are connected in parallel being fed to the monitoring unit. When a parallel connection has been recognized, the two voltage regulators and/or current regulators are coupled by setting mutually adjusted desired voltage values (USoll1, USoll2) and/or desired current values (ISoll1, ISoll2).