Microgrid Control Mode Switching for Stable Grid Interconnection
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Solution Overview
Problem
Microgrids do not effectively interoperate with distribution management systems, leading to unstable operations and potential blackouts due to complex control schemes and the simplification of microgrids as virtual power plants, which can result in suboptimal control and negative impacts on the distribution network.
Innovation Solution
A method and system that extends distribution network control into the microgrid by integrating a microgrid controller with a distribution network controller, allowing for selective control modes based on electrical entity thresholds and breaker status, enabling seamless integration and stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If microgrids are simplified as virtual power plants for control purposes, then the control scheme becomes simpler, but the interoperability with distribution management systems deteriorates and stability is compromised
Solution Approach 1:
The patent segments the control system into two distinct parts: a distribution management system (DMS) for macro-level coordination and a microgrid controller (MGC) for micro-level autonomous control. This segmentation allows each controller to operate at its appropriate level of detail without forcing oversimplification, thereby maintaining stability while managing complexity through hierarchical division of control functions.
Solution Approach 2:
The patent introduces an intermediary communication interface between the DMS and MGC that enables seamless information exchange without requiring either system to be simplified. The MGC acts as an intermediary that receives high-level instructions from the DMS while maintaining full awareness of microgrid conditions, allowing precise control decisions without compromising stability or interoperability.
2Speed
If the microgrid controller operates autonomously without integration with the distribution network controller, then the control responsiveness is improved, but the coordination and overall system stability deteriorate
Solution Approach 1:
The patent implements dynamic control modes that allow the MGC to switch between autonomous operation for rapid local response and coordinated operation with the DMS for system-wide stability. The controller dynamically adjusts its level of autonomy based on grid conditions, enabling fast response when needed while maintaining coordination when system stability requires centralized oversight.
Solution Approach 2:
The patent establishes continuous feedback loops between the MGC and DMS where the MGC reports microgrid status and receives coordination instructions. This feedback mechanism ensures that autonomous rapid responses are informed by and do not compromise overall system stability, as the DMS can provide corrective guidance when local actions may affect network-wide reliability.
3Productivity
If the distribution network controller manages the entire distribution network including the microgrid, then the overall network optimization is improved, but the microgrid control flexibility and autonomy deteriorate
Solution Approach 1:
The patent segments control authority between the DNSC and MGC, with the DNSC optimizing overall network performance and the MGC maintaining flexibility for microgrid-specific operations. This segmentation allows the DNSC to focus on macro-level efficiency while the MGC preserves adaptability for local conditions, resolving the contradiction between network-wide optimization and microgrid autonomy.
Solution Approach 2:
The patent merges the control functions of the DNSC and MGC through a unified communication framework that allows both controllers to operate simultaneously with complementary roles. The DNSC and MGC are merged in purpose rather than structure, enabling network optimization and microgrid flexibility to work together through coordinated control actions.
Data Source
AI summary
Method of controlling a distribution network and a microgrid controller adapted for the method. The distribution network comprises assets in a first part and a second part, which parts are selectively connected to each other into an interconnected state at a connection point (PCC). The method comprises monitoring and controlling the assets of the distribution network. In a first control mode, the first part is controlled by a distribution network controller and the second part is controlled by the microgrid controller. Especially, the method includes selecting between controlling the distribution network in the interconnected state in accordance with the first control mode, and controlling the distribution network in the interconnected state in accordance with a second control mode, in which second control mode the assets of the both the first part and the second part are controlled by the distribution network controller.