Voltage Set Point Control via Robust Optimization
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Solution Overview
Problem
Existing power grid voltage control methods are inefficient in handling fast power flow variations and uncertainties, particularly with the integration of renewable energy sources, leading to complex and time-consuming calculations.
Innovation Solution
A robust optimization method is employed using tolerance ranges for active and reactive power, allowing for flexible voltage control by determining a voltage set point that satisfies constraints across a range of uncertain parameters, with the option to minimize deviations from nominal voltages, and utilizing linear programming for efficient computation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If iterative solution of power flow equations is used to determine optimal voltage levels, then voltage control accuracy is improved, but calculation time increases significantly
Solution Approach 1:
The patent extracts the voltage optimization problem from the full iterative power flow solution by directly calculating optimal voltage levels at PV buses based on power flow variations at PQ buses, eliminating the need for repeated iterative solutions while maintaining control accuracy
Solution Approach 2:
The patent performs preliminary calculation of tolerance ranges for active power at PQ buses before determining voltage setpoints, allowing direct computation of optimal voltages without iterative refinement, thus reducing calculation time while preserving accuracy
2Adaptability or versatility
If tolerance ranges for active power are incorporated into voltage control, then adaptability to uncertain power flows is improved, but device complexity increases
Solution Approach 1:
The patent changes the control approach from fixed voltage setpoints to tolerance range-based optimization, where voltage setpoints are dynamically determined based on the incorporated tolerance ranges of active power, enhancing adaptability without requiring complex control hardware
Solution Approach 2:
The patent introduces tolerance ranges as an intermediary parameter that mediates between uncertain active power flows and voltage control decisions, allowing the system to adapt to uncertainties through mathematical modeling rather than complex control mechanisms
3Reliability
If robust optimization with tolerance ranges is implemented, then reliability of voltage control under uncertain conditions is improved, but computational complexity increases
Solution Approach 1:
The patent extracts the essential uncertainty characterization into tolerance ranges for active power, then directly incorporates these into the voltage optimization calculation, avoiding the need for full robust optimization frameworks while maintaining reliability under uncertain conditions
Solution Approach 2:
The patent performs preliminary determination of tolerance ranges and their impact on power flow before executing the voltage optimization, allowing the system to account for uncertainties in advance and compute reliable voltage setpoints with reduced computational effort
Data Source
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AI summary
For controlling a voltage in a power grid comprising a PV bus (PV1, PV2) and a PQ bus (PQ1,..., PQ3), a first tolerance range for an active power of the PV bus (PV1, PV2) and a second tolerance range for an active power of the PQ bus (PQ1,...,PQ3) are received. Furthermore, a first value for a reactive power (Q) of the PQ bus (PQ1,...,PQ3) is received. With that, a robust optimization process is run for a set of power flow equations. The first and second third tolerance range and the first reactive power value (Q) are input to the robust optimization process using the first and second tolerance range as robust optimization uncertainty. With that, the robust optimization process determines a voltage set point (vst) for the PV bus (PV1, PV2) so that the set of power flow equations is fulfilled for the first and second tolerance range. According to the determined voltage set point (vst) a voltage at the PV bus (PV1, PV2) is controlled.