Improved Correction Strategy for Power Flow Control Based on Multi-Machine Sensitivity Analysis

Abstract

Sensitivity analysis is a conventional power grid analysis method that has been widely used in active power safety correction of power systems. This method relies on linearizing the power flow equation, assuming that the control variable change will continue to act on the power system until a new steady-state operating point is reached. However, this method ignores the quasi-steady-state physical response of power equipment to various control operations, which makes the method not suitable for real-time decision-making. Therefore, according to the improved equal and opposite quantity adjustment principle, this paper proposes a practical power flow correction control strategy, that can avoid repeated and inefficient adjustments of the system. In the proposed method, the single-machine sensitivity matrix under the AC power flow model is obtained based on the Taylor series expansion of the power flow equation. Subsequently, the multi-machine sensitivity with no dependence on the choice of the balancing machine is proposed considering the quasi-steady-state method. The study is verified on a practical system, showing that the proposed method has an error of less than 1% with a rapid computation speed. The proposed method satisfies the requirements of real-time analysis and online control strategies, which can provide a more practical approach for active power safety correction.