Smart Grid-Flexible Power Inverter Mode Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solar power backup systems waste energy when the grid is on, as off-grid inverters cannot send power to the grid, and on-grid inverters shut down immediately when the grid is down to ensure safety, making them unsuitable for backup systems.
Innovation Solution
Smart and grid-flexible power inverters that can automatically switch between on-grid and off-grid modes, allowing solar power systems to supply energy to both the grid and AC loads, depending on grid conditions, using a single or multiple DC input channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If off-grid inverters are used to supply power to AC loads, then power supply capability during grid outages is improved, but energy waste occurs when the grid is on because power cannot be sent to the grid
Solution Approach 1:
The inverter dynamically switches between off-grid mode (supplying power to AC loads when grid is down) and on-grid mode (sending power to grid when available). The system detects grid status and automatically transitions between operating modes, allowing the same device to serve dual purposes and eliminate energy waste while maintaining power supply capability.
2Loss of energy
If on-grid inverters are used to send power to the grid, then energy utilization is improved, but reliability for backup power supply deteriorates because the inverter shuts down immediately when the grid is down
Solution Approach 1:
The inverter dynamically adapts its operation based on grid status. When grid is available, it operates in on-grid mode to maximize energy utilization by sending power to the grid. When grid fails, it immediately transitions to off-grid mode to provide backup power supply, thus maintaining both energy utilization and reliability without the shutdown limitation of conventional on-grid inverters.
Solution Approach 2:
The inverter is designed with multi-functionality to perform both on-grid power injection and off-grid backup supply using the same hardware platform. This universal design eliminates the need for separate inverters and ensures continuous operational capability across different grid conditions, improving both energy utilization and reliability.
3Device complexity
If a single inverter is used for both on-grid and off-grid operations, then device complexity is reduced, but adaptability to different grid conditions worsens
Solution Approach 1:
The single inverter incorporates dynamic control mechanisms that detect grid status (voltage, frequency, presence) and automatically adjust its operating parameters and mode accordingly. This dynamic adaptation allows the simplified single-inverter system to handle diverse grid conditions effectively, maintaining high adaptability without increasing physical complexity.
Solution Approach 2:
The inverter changes its operational parameters (output impedance, synchronization settings, power injection levels) based on detected grid conditions. When grid is present, it synchronizes and injects power; when grid fails, it switches to islanded operation with different parameters. This parameter adaptation enables a single device to handle multiple grid scenarios effectively.
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
Enables solar power systems to function as both grid-connected and backup systems, providing a cost-effective solution for areas with frequent power outages by optimizing energy usage and reducing disruption during grid instability.
Implementation Method 1
DC to AC power inverters that invert DC power from single or multiple DC power sources to single-phase or three-phase AC power
Data Source
AI summary
A method and apparatus is disclosed that can intelligently invert DC power from single or multiple DC sources to single-phase, split-phase, or three-phase AC power, supply the AC power to the electric power grid when the grid is on, or supply AC power to electric devices or loads when the grid is down. A Smart and Grid-Flexible Power Inverter, or On/Off-Grid Power Inverter, is disclosed that can work in either the on-grid or off-grid mode, and switch back and forth between the two modes manually or automatically depending on the power grid conditions. The system provides a simple and cost-effective solution for areas where the power grid has frequent outages or long downtimes.