Description:
Reference #: 01356
The University of South Carolina is offering licensing opportunities for Method for Intelligent Load Management in off-grid AC Systems
Background:
In an off-grid application, available power is limited and the total load power exceeds the maximum power generation capability. Therefore, it becomes important to manage and prioritize loads based on current system status. This is similar to demand response in grid systems. Additionally, if energy storage is available, the battery state of charge must be managed: the battery should act as a power source when power demand is high and recharge when extra power is available.
Invention Description:
In a grid‐connected application the frequency of the AC voltage is tightly controlled by the power utility and any local inverter – for example a solar inverter – has to be phase‐synchronized to the grid. However, in an off‐grid application there is no such constraint: the local inverter establishes the AC voltage and determines its frequency. Changing the AC voltage frequency provides a channel of communication between the inverter and the rest of the system that can be used for load management. The invention provides a method for intelligent load management in off-grid AC systems. The invention provides a method to control and prioritize loads, so that supply and demand can be balanced. The method is extremely robust and reliable.
Potential Applications:
Any off-grid AC application, such as off-grid houses, small industrial facilities and islanded microgrids. This invention will manage power more efficiently than currently systems and increase the effectiveness of the systems. There are load automation products available on the market, but they are intended for grid-connected applications. Some of them may be compatible with the invention.
Advantages and Benefits:
The method provides real-time intelligent management of loads, improving system functionality and performance. It allows flexible prioritization of loads, which do not require a separate communication channel, which may fail. The method is robust and has high reliability – if AC power is available, the information is automatically provided to the entire system.