DC Link Voltage Control via Segmented Converter Ranges
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Solution Overview
Problem
In electrical systems with a DC link, voltage control delays due to communication delays in higher-level controllers can lead to system instability and collapse, especially when power balances are abruptly changed, causing inefficiencies and potential system tripping.
Innovation Solution
Implementing individual converters for voltage control, each responsible for specific voltage ranges, allowing for dynamic response and faster reaction times to voltage disturbances, with the higher-level controller providing reference values and commands when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a higher-level controller with communication interface is used to control individual apparatuses, then the system can be easily operated and controlled, but communication delays cause control delays that lead to system instability and collapse
Solution Approach 1:
The control function is segmented between the higher-level controller (for reference values and commands) and individual converters (for real-time voltage control). Each converter independently controls DC link voltage within its specific voltage range, eliminating communication delays for critical voltage control while maintaining centralized coordination for overall system management.
Solution Approach 2:
The system dynamically switches control responsibility between different converters based on real-time voltage conditions. When DC link voltage enters a converter's controlled range, that converter takes over voltage control immediately without waiting for communication cycles, enabling dynamic adaptation to changing system conditions.
2Speed
If individual converters control voltage in specific voltage ranges, then dynamic response to voltage changes is improved, but device complexity increases
Solution Approach 1:
The voltage control range is segmented into multiple zones, with each converter responsible for a specific voltage range. This segmentation allows each converter to respond independently and immediately to voltage changes within its range, achieving fast dynamic response without requiring complex coordination for the entire voltage spectrum.
Solution Approach 2:
Each converter is equipped with local voltage control capability tailored to its specific voltage range. This local quality enables converters to autonomously respond to voltage disturbances in their designated ranges without complex global coordination, simplifying the overall control architecture while maintaining fast response.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances system security and energy efficiency by minimizing downtime and improving dynamic response to voltage changes, ensuring better energy capture and overall system stability.
Implementation Method 1
a controlled rectifier (2) having an input and an output, and an electrical power source (G) connected to the input of the controlled rectifier. The output of the controlled rectifier is connected to the DC link (1)
Implementation Method 2
at least one DC to DC converter (4) connected between the DC link (1) and the means for storing electrical energy (5), wherein the at least one DC to DC converter is configured to transfer power in both directions
Implementation Method 3
at least one DC to AC converter (3) connected between the DC link (1) and the motor (M), wherein the at least one DC to AC converter is configured to transfer power in both directions
Data Source
AI summary
An electrical system and method include a DC link, a controlled rectifier connected between the DC link and a power source, an energy storage, a DC to DC converter connected between the DC link and the energy storage, a motor, and a DC to AC converter connected between the DC link and the motor. The converters are configured to transfer power in both directions. The rectifier controls the DC voltage of the DC link when the DC link voltage is in a first voltage range. The DC to DC converter controls the DC voltage of the DC link by charging the energy storage when the DC link voltage is in a second voltage range, which has higher voltage values than the first voltage range, or by discharging the energy storage when the DC link voltage is in a third voltage range, which has lower voltages than the first voltage range.