AC Uninterruptible Power Supply with Switched Parallel Emergency Path
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Solution Overview
Problem
Existing uninterruptible power supply devices for information processing systems face efficiency degradation due to double-conversion processes and require complex, bulky, and expensive DC circuit breakers to manage arc disappearance during interruptions.
Innovation Solution
An uninterruptible power supply device with a switch-controlled AC power circuit that selectively connects to either a primary or emergency power path based on system state, allowing direct AC supply in normal conditions and utilizing an emergency device only when necessary, thereby reducing stress on the emergency system and allowing for the use of AC circuit breakers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a double-conversion uninterruptible power supply device is used, then the electrical system is protected from micro-cuts, but the efficiency is degraded to approximately 85%
Solution Approach 1:
The patent extracts the emergency conversion function from the continuous power path. The electrical system is connected directly to the AC supply network through a circuit breaker, bypassing the rectifier and inverter during normal operation. The emergency device (rectifier-inverter system) is taken out as a separate parallel path that only activates during micro-cuts, eliminating the efficiency penalty of continuous double-conversion while maintaining protection.
Solution Approach 2:
The power supply system is segmented into two independent paths: a direct AC connection path for normal operation and an emergency conversion path for micro-cut protection. The switchable circuit breaker segments the direct connection, allowing the system to selectively engage or disengage the emergency path based on network conditions, optimizing both efficiency and reliability.
2Reliability
If DC circuit breakers are used to manage arc disappearance during interruptions, then power supply interruptions are handled, but the device becomes bulky, complex, and expensive
Solution Approach 1:
Instead of using a DC circuit breaker to interrupt DC current and manage arc disappearance, the patent inverts the approach by using an AC circuit breaker to interrupt AC current. The circuit breaker is placed in the direct AC connection path, allowing it to naturally extinguish arcs during AC zero-crossings. This inversion simplifies the circuit breaker design while maintaining the ability to handle power supply interruptions.
3Reliability
If the emergency device is continuously loaded, then it is ready to respond to micro-cuts, but its lifespan is reduced due to increased stress
Solution Approach 1:
The emergency device operates periodically rather than continuously. The AC circuit breaker periodically connects or disconnects the direct AC path based on network conditions. During normal operation, the emergency device is disconnected and not loaded. When a micro-cut is detected, the breaker switches to engage the emergency device, which then operates only for the duration of the micro-cut event. This periodic action maintains readiness while significantly reducing cumulative stress and extending lifespan.
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
Improves efficiency by minimizing the use of emergency devices and extending their lifespan, while enabling the use of less complex and cost-effective AC circuit breakers, thus providing reliable and efficient power supply during network failures.
Implementation Method 1
comprises a rectifier for converting the alternating current into direct current (AC/DC converter function)
Implementation Method 2
an inverter for converting the direct current generated by the energy storage device into a alternating current (DC/AC converter function)
Data Source
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AI summary
This uninterruptible power supply (32) for an electrical power supply port (12) of an installation (10) comprising at least one electrical system (141, ..., 14n) connected to the power supply port includes: - a first circuit (36) for electrically connecting the power supply port (12) to an AC power supply network (34), - a backup device (40), comprising a rectifier (42), means (44, 46) for charging, storing, and discharging electrical energy, and an inverter (48), connectable to the power supply port (12). The backup device (40) is arranged in a second AC power supply circuit (38) connectable to the power supply port (12) in parallel with the first circuit (36).In addition, the uninterruptible power supply device (32) includes a switch (50) arranged and controlled to selectively connect the first (36) or second (38) circuit to the power supply port (12) depending on a state of the power supply of the electrical system (141, ..., 14n) in the installation (10).