Power Control Circuitry for Safe Grid Isolation and Reconnection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current AC grid-connected solar PV and energy storage systems face limitations in flexibility and cost, particularly in handling microinverters and mixed net metering scenarios, and require redundant equipment for islanded operations, which restrict their use during power outages or in disaster situations.
Innovation Solution
A power control system with time delay circuitry and power switches allows for safe disconnection and reconnection to alternative AC reference sources, enabling continued energy generation during main grid outages, using a supplemental grid-synchronized power generator and power control circuitry to manage switching between main and supplemental power sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If systems deactivate power provision when voltage or frequency outside defined range is detected, then safety is improved, but system flexibility and ability to operate during grid outages deteriorates
Solution Approach 1:
The system dynamically switches between grid-connected mode and islanded mode based on real-time grid conditions. The power conversion device can operate in multiple modes: synchronized with the grid when voltage and frequency are within ranges, or independently connected to local loads when grid conditions deteriorate, allowing the system to adapt to changing conditions while maintaining safety
Solution Approach 2:
The system changes its operational parameters based on grid conditions. When grid voltage or frequency goes outside defined ranges, the system transitions from grid-synchronized operation to independent islanded operation, changing its control parameters and connection state to maintain safe and reliable power supply under different conditions
2Reliability
If redundant equipment is added for islanded operations, then system reliability during outages is improved, but device complexity and cost increase
Solution Approach 1:
The power conversion device is designed with multi-functionality, serving both as a grid-connected inverter during normal operation and as an independent power source during islanded operations. This universal design eliminates the need for separate redundant equipment, reducing system complexity while maintaining reliability during outages
Solution Approach 2:
The patent combines the grid-connected power conversion function and the islanded power supply function into a single integrated power conversion device. By merging these functions, the system avoids duplicating equipment and reduces overall system complexity while ensuring reliable operation during grid outages
3Ease of operation
If direct connection to battery bank is used, then simplicity of configuration is improved, but adaptability to grid-connected operations and microinverters deteriorates
Solution Approach 1:
The power conversion device is designed to perform multiple functions: it can charge battery banks directly, connect to the grid for synchronized operation, and interface with microinverters. This multi-functional design maintains configuration simplicity while significantly improving adaptability to various operational modes including grid-connected operations and microinverter integration
Data Source
AI summary
Power control circuitry, power systems, and related methods are disclosed. A power system includes power control circuitry including a first power switch configured to couple a supplemental grid-synchronized power generator to a main grid power source, and a second power switch configured to couple the supplemental grid-synchronized power generator to a distribution unit configured to distribute electrical power to loads. The power control circuitry also includes time delay circuitry configured to control the first power switch and the second power switch. A method includes maintaining a supplemental grid-synchronized power generator coupled to a main grid power source while main electrical power is provided thereby, and decoupling the supplemental grid-synchronized power generator therefrom responsive to a cease in the main electrical power. The method also includes coupling the supplemental grid-synchronized power generator to a distribution unit a delayed period of time following a cease in the main electrical power.