Power System Synchronization Stability Without Equilibrium Prediction
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Solution Overview
Problem
Existing methods for analyzing transient stability in power systems, particularly the direct method, face challenges in predicting equilibrium points after faults due to system complexity, dynamics, and fluctuations, making it difficult to assess synchronization transient stability without specific equilibrium point information.
Innovation Solution
A method involving a synchronous energy function is developed to determine synchronization convergence regions based on state and algebraic variables, allowing transient stability assessment independent of equilibrium points, using the formula α(∥η(x,z)∥)≤(x,z)≤β(∥ξ(x,z)∥) and ∥h(x,z)∥≤c∥η(x,z)∥, with α, β, and γ being class functions, and h representing a continuously differentiable function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the direct method is used to analyze transient stability by constructing Lyapunov functions, then calculation time is reduced and quantitative stability information is provided, but the method requires advance knowledge of equilibrium points which are difficult to predict in complex power systems with new energy
Solution Approach 1:
The patent extracts and removes the dependency on equilibrium point information from the stability analysis process. By formulating a direct stability assessment method that evaluates transient stability based on system state variables and energy functions without requiring identification or prediction of equilibrium points, the method eliminates the bottleneck caused by complex equilibrium point prediction in systems with high new energy penetration
Solution Approach 2:
The patent changes the fundamental parameters of the stability analysis by transitioning from equilibrium-point-based parameters to state-variable-based parameters. The method uses algebraic equations involving system state variables (such as rotor angles, frequencies, and voltages) to directly assess stability, replacing the traditional approach that required solving for equilibrium points as intermediate steps
2Measurement precision
If time-domain simulation method is used to obtain accurate stability trajectory, then accuracy is improved, but calculation amount increases significantly and quantitative stability information cannot be provided
Solution Approach 1:
The patent substitutes the mechanical time-domain simulation process with an algebraic direct assessment method. Instead of performing step-by-step numerical integration of differential equations to simulate system trajectories, the method uses algebraic equations and energy functions to directly compute stability margins and assess stability, achieving both accuracy and efficiency
Solution Approach 2:
The patent performs preliminary formulation of algebraic stability criteria that can be directly evaluated without iterative simulation. By pre-establishing the algebraic relationships between system states and stability margins, the method enables immediate stability assessment upon system disturbance, avoiding the need for lengthy time-domain simulations
3Reliability
If direct method is applied to predict equilibrium point after fault, then stability region can be estimated, but the method fails when equilibrium point is non-unique or non-isolated which is common in modern power systems
Solution Approach 1:
The patent creates a universal stability assessment method that functions across diverse power system configurations, including traditional systems and those with high penetration of new energy sources. The algebraic approach based on state variables and energy functions is applicable regardless of whether equilibrium points are unique, non-unique, isolated, or non-isolated, making the method universally adaptable to modern power system complexities
Data Source
AI summary
A method for determining synchronization transient stability of a power system and an electronic device are provided. The synchronous energy function corresponding to the power system model is determined; the synchronization convergence region is determined according to the synchronization energy function; it is determined whether the power system is transient stable according to the synchronization convergence region and the initial value of power system after fault; and adjusting parameters of the power system in response to determining that the power system is transient unstable.