Polyphase UPS Dynamic Load Balancing for Smart Grid Efficiency
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Solution Overview
Problem
Conventional uninterruptible power supplies (UPS) face challenges in efficiently managing power distribution due to unbalanced loads across phases, leading to increased power losses and inefficiencies in smart grids, as they primarily rely on total load averages and lack dynamic adjustment capabilities to match real-time power demands.
Innovation Solution
A polyphase UPS system that dynamically adjusts loads by reducing current on one phase and increasing it on others, using current reference signals to maintain total output power, either in response to smart grid requests or local determinations, thereby balancing the grid and reducing losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional UPS relies on total load averages to determine baseload power, then power generation can be planned ahead of time, but power losses increase and efficiency decreases due to inability to match real-time demand
Solution Approach 1:
The UPS system dynamically adjusts its power consumption across different phases based on real-time grid conditions and load requirements. The control system continuously monitors phase imbalances and redistributes load dynamically, transitioning from static baseload planning to adaptive real-time power management that matches actual demand patterns.
Solution Approach 2:
The system changes operational parameters by adjusting the distribution of power across phases rather than maintaining fixed total load averages. By modifying phase-specific power consumption parameters while keeping total power requirements met, the system reduces losses without compromising adaptability.
2Reliability
If UPS increases baseload capacity to ensure reliability during peak demand, then service interruption is prevented, but wasted power increases due to excess generation
Solution Approach 1:
The system provides reliable power delivery through dynamic load redistribution rather than static capacity overprovisioning. When reliability is needed, the control system rapidly reallocates phases to meet demand, eliminating the need for continuous excess generation while maintaining service reliability.
Solution Approach 2:
The UPS system serves its own reliability needs by internally redistributing its load across phases rather than relying on external baseload capacity increases. The system self-adjusts to provide reliable power during peak demands without requiring wasteful overgeneration from the grid.
3Stress or pressure
If transformer phases are stepped up or down to balance line voltage, then voltage unbalance is corrected, but grid load remains unbalanced and distribution line losses persist
Solution Approach 1:
The UPS applies different power consumption characteristics to different phases rather than treating all phases uniformly. By adjusting individual phase loads based on their specific conditions and the overall grid state, the system achieves both voltage balance and load balance, eliminating distribution line losses caused by unbalanced currents.
Solution Approach 2:
The UPS performs multiple functions simultaneously: it provides uninterruptible power supply, balances line voltage, and balances grid load. This multi-functionality allows the system to address both voltage unbalance and load unbalance issues that previously required separate solutions.
4Loss of energy
If UPS operates with unbalanced phase loads, then simpler control is maintained, but power losses increase due to unbalanced grid current
Solution Approach 1:
The control system uses feedback from grid conditions and phase measurements to automatically adjust load distribution. By continuously monitoring phase imbalances and responding with appropriate load redistribution, the system reduces power losses through a relatively simple closed-loop control mechanism rather than complex open-loop calculations.
Data Source
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AI summary
A method for controlling an uninterruptible power supply (UPS) having a polyphase power input and an input power circuit coupled to the polyphase power input includes determining to reduce a load on a first phase of the polyphase power input, and in response thereto, controlling the input power circuit to reduce a first input current drawn from the first phase by a first amount and increase a second input current drawn from a second phase of the polyphase power input by a second amount. The UPS may determine to reduce the load on the first phase in response to a request from a smart grid to reduce the load on the first phase or in response to a local determination to reduce the load on the first phase.