Variable Amplitude Short-Circuit Current for UPS Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for generating short-circuit currents in uninterruptible power supplies (UPS) do not maximize the available capacity for protecting electrical faults, as they either exceed thermal limits or fail to efficiently trigger protection devices like fuses or circuit breakers.
Innovation Solution
A method that generates an alternating short-circuit current with an initial maximum amplitude tolerable by the UPS components, followed by a decreasing amplitude based on thermal inertia, optimizing energy delivery and thermal management to ensure efficient triggering of protection elements without overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a high amplitude short-circuit current is supplied to trigger protection devices quickly, then the energy delivery and fault isolation capability are improved, but the thermal conditions of the UPS components deteriorate and may cause degradation or damage
Solution Approach 1:
The patent applies dynamics by making the short-circuit current amplitude variable over time rather than constant. The control unit adjusts the current amplitude dynamically: starting with a high initial amplitude to quickly trigger protection devices, then progressively reducing the amplitude to maintain thermal safety. This temporal variation in current amplitude resolves the contradiction between delivering high energy for fast fault isolation and preventing excessive heating of components.
Solution Approach 2:
The patent implements periodic action through the oscillating nature of the short-circuit current. The control unit generates an oscillating current signal with periodic amplitude modulation, where the amplitude follows an envelope function that decreases over time. This periodic structure allows the system to deliver concentrated energy bursts during each cycle while providing thermal relief during the decreasing amplitude phases, thus balancing fault triggering effectiveness with component thermal safety.
2Reliability
If a fixed amplitude alternating current is supplied, then the thermal limit conditions are maintained, but the energy delivery capability and effectiveness of triggering protection devices are reduced
Solution Approach 1:
The patent resolves this contradiction by dynamically adjusting the current amplitude according to a time-varying envelope function. Instead of maintaining a fixed amplitude, the control unit varies the amplitude to be high during initial cycles for maximum energy delivery and fault triggering effectiveness, then progressively reduces it to maintain thermal safety. This dynamic approach allows the system to achieve both high power delivery when needed and thermal reliability over the extended duration.
Solution Approach 2:
The patent applies parameter changes by modifying the current amplitude parameter over time. The control unit changes the amplitude parameter from a constant value to a time-varying value that follows a decreasing envelope function. This parameter transformation allows the system to deliver higher peak power for effective fault triggering while ensuring that the time-averaged power remains within thermal safety limits, thus resolving the contradiction between energy delivery and thermal reliability.
3Power
If a two-level amplitude current is supplied with higher initial amplitude, then the energy delivery during first instants is improved, but the current must be reduced later to comply with thermal limits
Solution Approach 1:
The patent extends the two-level amplitude concept to a continuous dynamic variation. Instead of switching between just two discrete amplitude levels, the control unit implements a smooth, continuous amplitude modulation following a decreasing envelope function. This dynamic approach maintains the benefit of high initial energy delivery while providing a more refined and automated control strategy that adapts the current amplitude continuously, thereby managing thermal limits more effectively without significantly increasing operational complexity.
Solution Approach 2:
The patent incorporates feedback mechanisms through the control unit that monitors system state and automatically adjusts the current amplitude accordingly. The control algorithm uses feedback about thermal conditions and fault status to dynamically modulate the amplitude envelope, ensuring high initial power delivery while automatically complying with thermal limits as the fault response progresses. This feedback-driven approach manages the complexity of variable amplitude control while achieving the desired power delivery and thermal safety balance.
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 delivers a higher short-circuit current and greater energy over time, effectively maximizing the chances of triggering protection devices while maintaining thermal safety, thus isolating faults efficiently without overheating the UPS components.
Implementation Method 1
the various electrical components of the circuit heat up in response to this current
Data Source
Figure 1~3
Figure 4~5
Figure 6~8
AI summary
A method for generating a short-circuit by a power supply device (1) comprising electrical components (8) for causing the triggering of a protection element (6) connected between a load (3) and said power supply device (1). In response to the detection of an electrical fault situation in the power supply device (1), in order to eliminate the short-circuit fault with a shortened trigger time, an alternating short-circuit current is generated (120) having: - for a first period of said signal, a current amplitude that is equal to the maximum current amplitude that can be supported by the electrical components (8) of said power supply device (1), and - for the following periods, a current amplitude that decreases as a function of the thermal inertia of said electrical components (8).