Uninterruptible Power System Current Limiting Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Circuit breakers often trip due to high current demands from electrical devices, such as laser printers, causing power outages during critical tasks, as they are designed to protect against excessive current flow and cannot handle instantaneous high currents without shutting down.
Innovation Solution
An on-line uninterruptible power system comprising a first switch unit, a second switch unit, a charging circuit, a DC-AC conversion circuit, a power factor correction circuit, and a control circuit that limits input current to prevent circuit breaker tripping by enabling the DC-DC conversion circuit when voltage drops, ensuring current does not exceed the rated value.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If circuit breaker is used to protect against excessive current, then safety is improved, but power supply reliability deteriorates when high current is needed
Solution Approach 1:
The uninterruptible power system pre-charges a battery and maintains it in readiness before any power failure or overload occurs. When the system detects that the input current would exceed the circuit breaker rating, it immediately switches to battery power, preventing the circuit breaker from tripping and ensuring continuous power supply to the electrical device.
Solution Approach 2:
The uninterruptible power system acts as an intermediary device between the AC power source and the electrical device. It includes a power factor correction circuit that interfaces with the AC source, a battery that stores energy, and an inverter that converts DC battery power to AC output power. This intermediary system manages current flow to prevent circuit breaker tripping while ensuring reliable power delivery.
2Productivity
If electrical device draws high current instantaneously, then task completion capability is improved, but circuit breaker trips causing power interruption
Solution Approach 1:
The system changes the power source parameter from AC mains power to battery power when overload conditions are detected. The power factor correction circuit monitors input current and, upon detecting that it would exceed the circuit breaker rating, switches the operating mode to use battery power through the inverter, thereby maintaining continuous operation without tripping the circuit breaker.
Solution Approach 2:
The uninterruptible power system dynamically switches between two power sources based on real-time conditions. The control circuit continuously monitors the state of the AC power source and the battery, and automatically transitions between AC-powered mode and battery-powered mode to ensure continuous operation. This dynamic switching capability allows the system to maintain productivity during AC power failures or overload conditions.
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
Prevents circuit breaker tripping by managing high current demands, allowing critical tasks to continue uninterrupted by limiting input current to the rated value and providing necessary power through the power factor correction and battery support.
Implementation Method 1
the control circuit controls the operation of the power factor correction circuit to limit the magnitude of its input current to not exceed a first predetermined value
Implementation Method 2
The DC-AC conversion circuit is electrically coupled between the battery and the second switch unit
Implementation Method 3
The charging circuit is electrically coupled to the AC power source and a battery
Data Source
AI summary
An on-line uninterruptible power system and an operation method thereof are provided. The on-line uninterruptible power system comprises a first switch unit, a second switch unit, a charging circuit, a DC-AC conversion circuit, a power factor correction circuit and a control circuit. When the on-line uninterruptible power system is in a line mode, the control circuit controls the operation of the power factor correction circuit to limit the magnitude of its input current to not exceed a first predetermined value.