Power Grid Phase-Angle Synchronization for Safe Interconnection
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Solution Overview
Problem
Existing electrical power grid synchronization technologies often fail to synchronize the phase angle of alternating current (AC) voltages between independent grids effectively, leading to potential damage from inrush currents and instability when connecting grids, as they primarily focus on synchronizing amplitude and frequency without maintaining phase angle synchronization for an adequate duration.
Innovation Solution
A system and method that include a controller to determine synchronization metrics such as amplitude, frequency, and phase angle differences between nodes in two power grids, using these metrics to adjust dispatchable energy sources to synchronize the phase angle of AC voltages before electrical connection, ensuring seamless and safe grid interconnection by maintaining synchronization for a duration that covers the switching apparatus' operation time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing synchronization technologies focus primarily on synchronizing amplitude and frequency, then amplitude and frequency synchronization can be achieved, but phase angle synchronization is not maintained effectively leading to inrush currents and grid instability
Solution Approach 1:
The system performs preliminary phase angle synchronization by adjusting dispatchable energy sources before the switching apparatus connects the grids. The controller continuously monitors phase angle differences and applies corrective actions in advance to ensure phase angles are synchronized and remain synchronized throughout the switching operation, preventing inrush currents and instability.
Solution Approach 2:
The system implements continuous feedback by monitoring the phase angle difference between the two grids in real-time. The controller uses this feedback information to dynamically adjust the dispatchable energy sources, ensuring phase angle synchronization is maintained throughout the connection process. This closed-loop control prevents phase angle deviations that could cause inrush currents.
2Reliability
If the switching apparatus operation time is not covered by synchronization duration, then connection speed can be improved, but phase angle desynchronization occurs during switching causing harmful effects
Solution Approach 1:
The system establishes phase angle synchronization in advance before the switching apparatus operates. The controller ensures phase angles are synchronized and maintains this synchronization throughout the entire switching operation duration. By preparing the synchronization state beforehand and maintaining it through the switching period, the system eliminates phase angle desynchronization without requiring extended synchronization time beyond the switching operation.
3Productivity
If amplitude and frequency are synchronized without adequate phase angle control, then connection can proceed faster, but grid stability and safety are compromised
Solution Approach 1:
The system implements real-time feedback control of phase angle differences during the connection process. The controller continuously monitors phase angle synchronization status and dynamically adjusts dispatchable energy sources to maintain synchronization. This feedback mechanism ensures grid stability is maintained throughout the connection operation, allowing faster connection speeds without compromising safety.
Solution Approach 2:
The system dynamically changes operational parameters of dispatchable energy sources (such as frequency and voltage output) to maintain phase angle synchronization. By adjusting these parameters in real-time based on phase angle differences, the system ensures stable and safe grid connection while maintaining connection speed efficiency.
Data Source
AI summary
Electrically connecting a first node of a first power grid to a second node of a second power grid includes: determining a phase angle of at least one phase of an AC voltage at the first node in the first power grid; determining a phase angle of at least one phase of an AC voltage at the second node in the second power grid; determining a phase angle metric based on comparing the phase angle of the AC voltage in the first power grid to the phase angle of the AC voltage in the second power grid; comparing the phase angle metric to a phase angle threshold; and if the phase angle metric is equal to or exceeds the phase angle threshold, controlling a dispatchable energy source in the first power grid in a P-Q control mode to adjust the phase angle of at least one phase of the AC voltage at the first node.