UPS Generator Transition for Power Continuity
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Solution Overview
Problem
Power systems with generators face delays in transitioning from a primary power source to a standby generator, affecting the availability of critical loads due to the time required to stabilize the generator and connect it to the load bus.
Innovation Solution
A method and system that utilize an uninterruptible power supply (UPS) to generate voltage on the bus and synchronize the generator, allowing power transfer from the UPS to the generator once it reaches a desired output state, thereby reducing the time needed for the generator to stabilize and connect to the load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the generator is started and stabilized before being connected to the load bus, then the generator output voltage and frequency are within acceptable limits, but the transition time causes negative effects on load availability
Solution Approach 1:
The UPS is pre-positioned and pre-charged during normal operation, ready to immediately supply power to the load bus when utility power fails. This preliminary preparation eliminates the need to wait for generator stabilization before powering critical loads.
Solution Approach 2:
The UPS acts as an intermediary power source between the utility source and the load bus during transition periods. It temporarily supplies power to the load bus while the generator is being started and stabilized, bridging the gap between utility failure and generator readiness.
2Reliability
If the generator is connected to the load bus after stabilization, then power transfer is stable, but critical loads experience power interruption during the transition period
Solution Approach 1:
The UPS maintains continuous power supply to the load bus throughout the transition period. By seamlessly switching from utility power to UPS power and then to generator power, the system ensures uninterrupted power delivery to critical loads, maintaining the continuity of useful action without interruption.
3Reliability
If the UPS provides power during generator transition, then load availability is maintained, but the UPS must operate in reverse power flow mode
Solution Approach 1:
The UPS operational mode is dynamically changed from normal rectifier-inverter operation to reverse power flow operation during the transition period. The converter that normally rectifies AC to DC is operated in reverse to invert DC to AC, allowing the UPS to supply power to the load bus from the battery/DC link during generator startup.
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 enables faster transition and stabilization of the generator, ensuring continuous power availability to critical loads by using the UPS to support power until the generator is online, thus improving the overall system's reliability and reducing downtime.
Implementation Method 1
A loss of a power source for a bus is detected. Responsive to detecting the loss of the power source, a voltage is generated on the bus using an uninterruptible power supply (UPS).
Implementation Method 2
A generator is transitioned to a desired output state concurrent with generating the voltage on the bus using the UPS. The generator is coupled to the bus responsive to the generator attaining the desired output state to enable power transfer from the generator to the UPS (210) and the load.
Data Source
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AI summary
A loss of power source for a bus is detected. Responsive to detecting the loss of the power source, a voltage is generated on the bus using an uninterruptible power supply (UPS). A generator is transitioned to a desired output state concurrent with generating the voltage on the bus using the UPS. The generator is coupled to the bus responsive to the generator attaining the desired output state. The UPS may be used to provide power to a lead connected to the bus while the generator is in transition. For example, detecting the loss of the power source may be preceded by operating a converter of the UPS coupled to the bus as a rectifier and generating the voltage on the bus using the UPS may include operating the converter of the UPS as an inverter.