Microgrid Load Shedding for Stable Renewable-Powered Production
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Solution Overview
Problem
The variability of green energy sources like solar and wind power leads to potential tripping or disconnection of loads and power sources, limiting the utilization of renewable energy, especially in remote locations where generation conditions are optimal.
Innovation Solution
A method and device for operating a production plant with green generating systems, using a controller to manage power dispatch and buffer, and selectively reducing loads based on criteria such as restart, storage, and product closeness to balance power supply and demand, ensuring maximum utilization of renewable energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If green generating systems operate at maximum capacity, then renewable energy utilization is improved, but power supply stability deteriorates due to variability causing tripping or disconnection
Solution Approach 1:
The controller performs preliminary assessment of multiple load shutdown scenarios before actual load shedding occurs. It calculates predicted frequency deviations and identifies optimal shutdown sequences in advance, allowing the system to prepare mitigation strategies before stability issues arise from maximum green energy operation
Solution Approach 2:
The system dynamically adjusts the operating state of loads based on real-time green energy availability and system frequency conditions. The controller continuously monitors and reconfigures which loads remain online versus those that are shed, creating a dynamic balance between maximizing renewable utilization and maintaining power supply stability
2Reliability
If loads are reduced to maintain stability, then power supply stability is improved, but renewable energy utilization deteriorates due to limiting power usage below production capacity
Solution Approach 1:
The controller implements feedback control by continuously monitoring system frequency and green energy generation levels, then adjusting load configuration accordingly. When frequency deviates from acceptable ranges, the controller automatically sheds appropriate loads and provides feedback on the new system state, creating a closed-loop system that maximizes renewable utilization while maintaining stability
Solution Approach 2:
The system changes operational parameters by selectively shutting down specific loads based on calculated frequency deviations and load characteristics. Rather than uniformly reducing all loads, the controller modifies the operational state of individual loads or load groups, changing system parameters dynamically to accommodate variable green energy input while maintaining overall stability
3Productivity
If multiple loads operate simultaneously, then productivity is improved, but system control complexity increases making it difficult to manage variable power sources
Solution Approach 1:
The controller segments the total load into multiple independent load groups or individual controllable loads, each with distinct shutdown characteristics and priorities. This segmentation allows selective control of specific loads rather than treating the entire production system as a single entity, simplifying the control strategy while maintaining productivity through partial load operation
Solution Approach 2:
The system implements partial action by shutting down only the necessary portion of loads required to maintain stability, rather than shutting down all loads or using excessive mitigation measures. The controller calculates the minimum load reduction needed to correct frequency deviations, allowing other loads to continue operating and maintaining overall productivity
Data Source
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AI summary
A method of operating a microgrid while isolated from an outside grid includes dispatching a plurality of green generating systems to deliver a first quantity of power to the microgrid. The method also includes drawing a second quantity of power from the microgrid to power a system that operates to produce a final output product. The drawing step further includes powering a first load to produce a first output product in response to the consumption of a first portion of the second quantity of power and powering a second load to produce the final output product based in part on the first output product and in response to the consumption of a second portion of the second quantity of power. The method also includes calculating a power difference between the first quantity of power and the second quantity of power and reducing the second quantity of power in response to the power difference indicating that the second quantity of power is greater than the first quantity of power. The reducing step follows a sequence of reductions which includes calculating a selection criterion for each of the first load and the second load based in part on at least two of a restart criterion, a product storage criterion, a final product closeness criterion, an oversize criterion, and a magnitude criterion of each of the first load and the second load, and reducing one of the first portion of the second quantity of power and the second portion of the second quantity of power based on the calculation of the selection criteria.