Distribution Network Voltage Control Under Unknown Line Parameters
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Solution Overview
Problem
Existing real-time voltage control techniques for electrical distribution networks with non-linear power flows lack performance and stability guarantees, and rely heavily on numerical analysis, making them unsuitable for practical applications.
Innovation Solution
A processor-implemented method and system for real-time voltage stabilization that involves obtaining load and distributed energy resources data, simulating the network using a non-linear power flow model, predicting line-parameters using online convex optimization and Gauss-Seidel techniques, and determining stable control signals to stabilize the voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional voltage controllers (tap-changing transformer, series and shunt capacitors) are used, then the system is simple to operate, but they cannot control voltage variations quickly enough due to slow response to rapid voltage swings caused by renewable energy integration
Solution Approach 1:
The patent implements dynamic voltage control through real-time optimization algorithms that continuously adjust control signals based on current operating conditions. The system solves optimization problems at each time step to determine optimal control actions, enabling rapid response to voltage variations while maintaining adaptability to changing network conditions and renewable energy outputs.
2Measurement precision
If real-time voltage control techniques based on non-linear power flow equations are used, then the control accuracy is improved, but performance and stability guarantees are lost due to reliance on numerical analysis techniques
Solution Approach 1:
The patent transforms the non-linear power flow equations into a form suitable for convex optimization by changing the parameter representation. Specifically, it uses squared voltage magnitudes and transformed power flow equations that can be expressed as convex constraints, enabling the use of efficient convex optimization algorithms while maintaining accuracy in modeling non-linear network behavior.
3Reliability
If real-time voltage control techniques with stability guarantees are used, then the system reliability is improved, but they can only be applied to linear power flow equations which do not accurately represent practical non-linear distribution networks
Solution Approach 1:
The patent replaces traditional numerical analysis methods with convex optimization techniques. By formulating the voltage control problem as a convex optimization problem with explicitly defined constraints and objective functions, the system achieves both theoretical stability guarantees and accurate modeling of non-linear power flow characteristics, eliminating the need to choose between reliability and adaptability.
4Productivity
If exact knowledge of grid topology and line-parameters is available, then the control performance is optimized, but this exact knowledge is not always available due to frequent distribution grid reconfiguration and time-varying system parameters
Solution Approach 1:
The patent incorporates preliminary estimation of line parameters using available measurement data before solving the optimization problem. By using on-line parameter estimation techniques and previous operating conditions to initialize parameter values, the system prepares accurate starting points for optimization even when exact parameters are unknown, improving convergence and control performance under uncertain conditions.
Data Source
AI summary
The disclosure relates generally to methods and systems for real-time voltage stabilization of electrical distribution networks with non-linear power flows. Existing real-time voltage control techniques are neither performance nor stability guarantees. The present disclosure proposes an online robust control algorithm, which operates without knowing an exact information of the line-parameters and resolves the voltage stability problem. In the proposed method a load data, a distributed energy resources (DER) data, and a network data of an electrical distribution network is obtained, to obtain a voltage profile at each time-step of the electrical distribution network. Next, line-parameters of the electrical distribution network are predicted using an on-line convex optimization technique and a Gauss-Seidel technique. Then, a stable control signal for each bus that stabilizes a voltage of the electrical distribution network is determined to utilize the stable voltage for the voltage stabilizing of the electrical distribution network in real-time.