Station Power Supply Device Regenerative Energy Buffering
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Solution Overview
Problem
Conventional techniques for using surplus regenerative power from trains in station-building power supply systems lead to intermittent and destabilizing fluctuations in the AC power system due to the direct regeneration of power into the AC system.
Innovation Solution
A station-building power supply device that includes a feeding-voltage detection unit, a capacitor unit for storing surplus regenerative power, an SOC detection unit, a first power conversion unit for bidirectional DC/DC conversion between the feeder and capacitor, a second power conversion unit for converting DC power to AC, and a control unit that manages these components to stabilize power supply by charging the capacitor when surplus power is generated and discharging it to the station load when needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If surplus regenerative power is directly transformed into AC power and supplied to the AC system, then the regenerative power is effectively utilized, but the AC system power amount fluctuates intermittently and becomes destabilized
Solution Approach 1:
A capacitor unit is introduced as an intermediary energy storage device between the regenerative power source and the AC system. The capacitor unit absorbs surplus regenerative power when available and releases stored energy when needed, mediating the connection to prevent direct fluctuations from reaching the AC system while maintaining effective utilization of regenerative power.
Solution Approach 2:
The capacitor unit performs preliminary energy storage by accumulating surplus regenerative power during periods when regenerative power exceeds consumption. This preliminary action allows the system to prepare energy in advance, releasing it during periods of deficiency to maintain stable AC system operation without direct fluctuations.
2Stability of the object's composition
If a capacitor unit is introduced to store surplus regenerative power, then AC system stability is improved, but the device complexity increases
Solution Approach 1:
The capacitor unit serves multiple functions: it stores surplus regenerative power, releases energy during power deficiency, and acts as a buffer to stabilize the AC system. This multi-functionality reduces the need for separate components for each function, thereby limiting the increase in device complexity while achieving stability.
Solution Approach 2:
The system dynamically adjusts operational parameters such as charging and discharging voltages of the capacitor unit based on real-time conditions. By changing these parameters adaptively, the system optimizes performance without requiring complex structural modifications, thus improving stability while controlling device complexity.
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 configuration effectively utilizes surplus regenerative power while maintaining stable AC power supply to station loads, reducing fluctuations in the AC system by storing and managing power through the capacitor unit.
Implementation Method 1
a capacitor unit that stores therein the surplus regenerative power
Implementation Method 2
a first power conversion unit that performs DC/DC power conversion in both directions between a feeder and the capacitor unit
Implementation Method 3
a second power conversion unit that converts DC power supplied from the capacitor unit to AC power and supplies the AC power to the station load
Data Source
Figure 1
Figure 2(a)~2(d)
Figure 3(a)~3(b)
AI summary
To provide a station-building power supply device that can effectively use surplus regenerative power while suppressing fluctuations in the amount of power of an AC system that supplies AC power to station loads. The station-building power supply device includes a capacitor unit 9 that stores therein surplus regenerative power in an electrical transformation zone, a first power conversion unit 11 that performs DC/DC power conversion in both directions between a feeder 6 and the capacitor unit 9, and a second power conversion unit 12 that converts DC power supplied from the capacitor unit 9 to AC power to be supplied to the station loads 4. A first voltage threshold for detecting the occurrence of surplus regenerative power generated in the electrical transformation zone is set for a feeding voltage and a first SOC threshold for detecting whether the capacitor unit 9 can discharge is set for an SOC of the capacitor unit 9. The first power conversion unit 11 is controlled such that power is supplied from the feeder 6 to the capacitor unit 9 to charge the capacitor unit 9 when the feeding voltage exceeds the first voltage threshold, and the second power conversion unit 12 is controlled such that power is supplied from the capacitor unit 9 to the station loads 4 when the SOC of the capacitor unit 9 exceeds the first SOC threshold.