PCC Power Control With Compensators for PEDG Stability
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Solution Overview
Problem
Power Electronics Dominated Grids (PEDGs) experience transient stability issues due to rapid changes in active and reactive power, leading to voltage and frequency fluctuations, which can destabilize industrial facilities connected to these grids, particularly those with strong and dynamically varying loads like electric arc furnaces.
Innovation Solution
A control system comprising power electronics blocks, compensators, and a power controller that coordinates load responder and compensator responder components via fast data communication to stabilize voltage and frequency at the point of common coupling by adjusting set points and providing inertial support.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If variable energy sources are integrated into the power grid to increase renewable energy contribution, then the green energy supply is improved, but voltage and frequency stability deteriorates due to low inertia and varying grid strength
Solution Approach 1:
The patent introduces a universal interconnect device as an intermediary between the internal grid and large-scale grid. This device includes a power quality compensator and energy storage device that mediate the interaction, absorbing/generating reactive and active power respectively, thereby stabilizing the grid connection point and preventing the propagation of instability from variable energy sources to the broader power system.
Solution Approach 2:
The patent changes the operational parameters of the industrial facility by implementing dynamic control of power consumption. The controller adjusts active and reactive power demand in response to grid conditions, transforming the facility from a passive load into an active participant that can modulate its power characteristics to support voltage and frequency stability during transient events.
2Adaptability or versatility
If transient events occur causing rapid changes in active and reactive power, then power flexibility is improved, but voltage and frequency stability deteriorates due to disturbed supply and demand balance
Solution Approach 1:
The patent implements a closed-loop feedback control system where the controller continuously monitors grid conditions and power consumption, and dynamically adjusts the operation of power electronics blocks and energy storage devices. This feedback mechanism enables the system to respond to transient events by detecting deviations in voltage and frequency and correcting them through real-time modulation of active and reactive power, thereby maintaining stability despite rapid power changes.
Solution Approach 2:
The patent employs energy storage devices that can be pre-charged or pre-discharged based on predicted or detected transient events. The power quality compensator is pre-configured to provide immediate reactive power support when transients occur, acting before the full impact of the disturbance propagates through the system, thus preventing voltage collapse or frequency excursions.
3Manufacturing precision
If voltage and frequency are tightly coupled in a Power Electronics Dominated Grid, then power control precision is improved, but stability against transient events deteriorates due to amplified impact of disturbances
Solution Approach 1:
The patent segments the power system into distinct functional zones: the internal grid with variable energy sources, the universal interconnect device with power quality compensator and energy storage, and the large-scale grid. This segmentation isolates the tight coupling effect to the internal grid level where precision control is beneficial, while the interconnect device acts as a buffer that prevents the amplification of transient events from propagating to the larger, more stability-critical grid infrastructure.
Data Source
AI summary
An industrial facility connected to a power grid includes a distribution grid connected with the power grid at a point of common coupling; at least one load connected via at least one power electronics block to the distribution grid, each power electronics block adapted for converting a current from the distribution grid into a current supplied to the respective load and each power electronics block including a load responder component adapted for determining a load demand of the respective load; at least one compensator connected to the distribution grid, each compensator being adapted for stabilizing a voltage and/or a frequency of a current in the distribution grid and each compensator including a compensator responder component adapted for receiving a stabilizing command and for applying the stabilizing command to the respective compensator; and a power controller in data communication with the one or more load responder components and the one or more compensator responder components, the power controller being adapted for receiving load demands(50) from the one or more load responder components, for determining stabilizing commands from the load demands and for sending the stabilizing commands to the one or more compensator responder components.