A novel discrete-time state-space model for real-time simulation of power system based on characteristics of capacitor and inductor

Abstract

With the development of the power system, the dynamic characteristics of power systems become more and more complex because of the growing scales. As a critical tool in power system researches, the real-time simulation suffers from issues of slow speed and low accuracy. This paper proposes a novel discrete-time state-space model based on characteristics of capacitor and inductor, which aims to improve the speed and accuracy of real-time simulation in power systems. In the proposed method, the characteristic equations of capacitor and inductor are firstly discretized by numerical integration methods. Subsequently, mathematical methods and formulas are employed to derive the new discrete-time state-space model. Compared with the traditional discrete-time state-space model, the proposed method effectively reduces computational cost when applying the same implicit numerical integration method of third-order or higher. Additionally, the accuracy and speed of real-time simulation can be synthetically improved by employing higher order numerical integration methods for the selected state variables. Finally, the advantages of the proposed method are validated through three real-time simulations of an RLC circuit system, a grid-connected inverter system, and a boost-inverter system.