Backup Power Supply Switching Between DC and AC Battery Strings
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Solution Overview
Problem
Existing energy systems, such as wind turbines, require backup power supplies for critical loads like yaw and pitch motors, leading to increased costs and maintenance due to the need for multiple battery packs and UPS systems.
Innovation Solution
A multi-phased energy storage system that can supply both AC and DC voltage, reducing the need for dedicated battery packs by using a switching arrangement with H-bridge configurations to switch between DC and AC output based on grid availability, enabling online and offline UPS functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate battery packs are used for online UPS and offline UPS, then backup power reliability is improved, but system complexity and maintenance costs increase
Solution Approach 1:
The patent combines online UPS and offline UPS battery packs into a single shared battery pack. The battery pack can be configured to supply power to either the online UPS or offline UPS depending on operational needs, eliminating the need for separate battery packs and reducing overall system complexity while maintaining backup power reliability.
Solution Approach 2:
The single battery pack is designed with multi-functionality to serve dual purposes: it can operate as an online UPS battery pack during normal operation and as an offline UPS battery pack during grid failures. This universal design allows one battery pack to replace what would traditionally require two separate battery packs.
2Reliability
If multiple battery packs are deployed for different UPS systems, then power availability is improved, but maintenance costs increase
Solution Approach 1:
By merging the battery packs into a single shared resource, the system reduces the total number of battery packs from two to one. This directly lowers maintenance costs as there is less equipment to service, while power availability is maintained through intelligent switching between online and offline UPS modes.
3Reliability
If AC voltage is continuously supplied to backup supply, then power quality is improved, but battery cycle life decreases
Solution Approach 1:
The system dynamically switches between different operational modes based on grid availability. During normal operation, the battery pack supplies DC voltage to the backup supply. During grid failures, it switches to supplying AC voltage through the inverter. This dynamic operation reduces the time the battery pack spends in heavy AC cycling, thereby extending its operational life.
Solution Approach 2:
The system employs periodic action by only activating AC voltage supply through the inverter when grid failure occurs. During normal grid operation, the battery pack remains in a lighter DC supply mode. This periodic switching between operational states reduces overall battery stress and extends cycle life.
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
Reduces the number of battery packs required, lowers maintenance costs, and maintains power supply to critical loads during grid failures, while extending battery life by minimizing heavy cycling.
Implementation Method 1
the switching arrangements comprises four semiconductor switches in an H-bridge configuration
Data Source
AI summary
A power backup system includes a multi phased energy storage and a backup supply. The energy storage includes battery strings, each capable of supplying either an AC or DC voltage to a load. During normal operation, the backup supply is configured for being supplied with an AC voltage from a utility grid and being connectable to a DC voltage supplying battery string of the energy storage. During abnormal operation, the backup supply is configured for, in a first period of time, being supplied from a DC output voltage established by the a first battery string and after expiration of the first period of time being supplied from the AC output voltage established by a second battery string.